diff -Nru basex-8.1.1/basex-api/pom.xml basex-8.2.3/basex-api/pom.xml
--- basex-8.1.1/basex-api/pom.xml	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/pom.xml	2015-07-14 10:54:40.000000000 +0000
@@ -7,7 +7,7 @@
   <parent>
     <groupId>org.basex</groupId>
     <artifactId>basex-parent</artifactId>
-    <version>8.1.1</version>
+    <version>8.2.3</version>
     <relativePath>..</relativePath>
   </parent>
 
diff -Nru basex-8.1.1/basex-api/.settings/checkstyle.xml basex-8.2.3/basex-api/.settings/checkstyle.xml
--- basex-8.1.1/basex-api/.settings/checkstyle.xml	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/.settings/checkstyle.xml	2015-07-14 10:54:40.000000000 +0000
@@ -1,12 +1,12 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE module PUBLIC "-//Puppy Crawl//DTD Check Configuration 1.3//EN" "http://www.puppycrawl.com/dtds/configuration_1_3.dtd">
 
-<!--
-    This configuration file was written by the eclipse-cs plugin configuration editor
+<!--
+    This configuration file was written by the eclipse-cs plugin configuration editor
 -->
-<!--
-    Checkstyle-Configuration: BaseX Checkstyle
-    Description: none
+<!--
+    Checkstyle-Configuration: BaseX Checkstyle
+    Description: none
 -->
 <module name="Checker">
   <property name="severity" value="warning"/>
@@ -26,7 +26,7 @@
     <module name="IllegalImport"/>
     <module name="RedundantImport"/>
     <module name="LineLength">
-      <property name="ignorePattern" value="^import"/>
+      <property name="ignorePattern" value="^(import| \*)"/>
       <property name="max" value="100"/>
       <property name="tabWidth" value="2"/>
     </module>
@@ -50,7 +50,6 @@
     </module>
     <module name="ModifierOrder"/>
     <module name="RedundantModifier"/>
-    <module name="AvoidNestedBlocks"/>
     <module name="EqualsHashCode">
       <property name="severity" value="ignore"/>
       <metadata name="net.sf.eclipsecs.core.lastEnabledSeverity" value="inherit"/>
diff -Nru basex-8.1.1/basex-api/src/main/java/org/basex/api/xmldb/BXCollection.java basex-8.2.3/basex-api/src/main/java/org/basex/api/xmldb/BXCollection.java
--- basex-8.1.1/basex-api/src/main/java/org/basex/api/xmldb/BXCollection.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/java/org/basex/api/xmldb/BXCollection.java	2015-07-14 10:54:40.000000000 +0000
@@ -10,7 +10,6 @@
 import org.basex.core.*;
 import org.basex.core.cmd.*;
 import org.basex.data.*;
-import org.basex.data.atomic.*;
 import org.basex.io.*;
 import org.basex.util.*;
 import org.basex.util.list.*;
diff -Nru basex-8.1.1/basex-api/src/main/java/org/basex/api/xmldb/BXDatabase.java basex-8.2.3/basex-api/src/main/java/org/basex/api/xmldb/BXDatabase.java
--- basex-8.1.1/basex-api/src/main/java/org/basex/api/xmldb/BXDatabase.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/java/org/basex/api/xmldb/BXDatabase.java	2015-07-14 10:54:40.000000000 +0000
@@ -76,8 +76,8 @@
       final String main = uri.startsWith(XMLDBC) ? uri : XMLDBC + uri;
       if(main.startsWith(XMLDBURI)) {
         final String host = main.substring(XMLDBURI.length());
-        final String localhost = S_LOCALHOST + ':' +
-            ctx.soptions.get(StaticOptions.SERVERPORT) + '/';
+        final int port = ctx.soptions.get(StaticOptions.SERVERPORT);
+        final String localhost = S_LOCALHOST + ':' + port + '/';
         if(host.startsWith(localhost)) return host.substring(localhost.length());
       }
     }
diff -Nru basex-8.1.1/basex-api/src/main/java/org/basex/api/xmldb/BXQueryService.java basex-8.2.3/basex-api/src/main/java/org/basex/api/xmldb/BXQueryService.java
--- basex-8.1.1/basex-api/src/main/java/org/basex/api/xmldb/BXQueryService.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/java/org/basex/api/xmldb/BXQueryService.java	2015-07-14 10:54:40.000000000 +0000
@@ -4,7 +4,6 @@
 
 import java.util.*;
 
-import org.basex.data.*;
 import org.basex.query.*;
 import org.basex.query.value.*;
 import org.basex.query.value.node.*;
@@ -71,7 +70,8 @@
   @Override
   public BXResourceSet query(final String query) throws XMLDBException {
     final DBNodes nodes = coll.ctx.current();
-    return query(query, DBNodeSeq.get(new IntList(nodes.pres), nodes.data, nodes.all, nodes.all));
+    final boolean all = nodes.all();
+    return query(query, DBNodeSeq.get(new IntList(nodes.pres()), nodes.data(), all, all));
   }
 
   @Override
diff -Nru basex-8.1.1/basex-api/src/main/java/org/basex/BaseXHTTP.java basex-8.2.3/basex-api/src/main/java/org/basex/BaseXHTTP.java
--- basex-8.1.1/basex-api/src/main/java/org/basex/BaseXHTTP.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/java/org/basex/BaseXHTTP.java	2015-07-14 10:54:40.000000000 +0000
@@ -97,8 +97,8 @@
     }
 
     // start web server in a new process
+    final Connector connector = jetty.getConnectors()[0];
     if(service) {
-      final Connector connector = jetty.getConnectors()[0];
       start(connector.getPort(), connector instanceof SslSelectChannelConnector, args);
 
       for(final Connector c : jetty.getConnectors()) {
@@ -110,10 +110,10 @@
     }
 
     // request password on command line if only the user was specified
-    if(!Options.getSystem(StaticOptions.USER).isEmpty()) {
-      while(Options.getSystem(StaticOptions.PASSWORD).isEmpty()) {
+    if(!Prop.get(StaticOptions.USER).isEmpty()) {
+      while(Prop.get(StaticOptions.PASSWORD).isEmpty()) {
         Util.out(PASSWORD + COLS);
-        Options.setSystem(StaticOptions.PASSWORD, Util.password());
+        Prop.put(StaticOptions.PASSWORD, Util.password());
       }
     }
 
@@ -121,7 +121,7 @@
     try {
       jetty.start();
     } catch(final BindException ex) {
-      throw new IOException(HTTP + ' ' + SRV_RUNNING, ex);
+      throw new IOException(Util.info(HTTP + ' ' + SRV_RUNNING_X, connector.getPort()), ex);
     }
     // throw cached exception that did not break the servlet architecture
     final IOException ex = HTTPContext.exception();
@@ -174,9 +174,7 @@
 
     // server has been started in a separate process and needs to be stopped
     if(!bool(StaticOptions.HTTPLOCAL, mprop)) {
-      final int port = num(StaticOptions.SERVERPORT, mprop);
-      final int eport = num(StaticOptions.EVENTPORT, mprop);
-      BaseXServer.stop(port, eport);
+      BaseXServer.stop(num(StaticOptions.SERVERPORT, mprop));
     }
   }
 
@@ -187,7 +185,7 @@
    * @return numeric value
    */
   private static int num(final NumberOption option, final StaticOptions sopts) {
-    final String val = Options.getSystem(option);
+    final String val = Prop.get(option);
     return val.isEmpty() ? sopts.get(option) : Strings.toInt(val);
   }
 
@@ -198,7 +196,7 @@
    * @return boolean value
    */
   private static boolean bool(final BooleanOption option, final StaticOptions sopts) {
-    final String val = Options.getSystem(option);
+    final String val = Prop.get(option);
     return val.isEmpty() ? sopts.get(option) : Boolean.parseBoolean(val);
   }
 
@@ -268,45 +266,42 @@
       if(arg.dash()) {
         switch(arg.next()) {
           case 'd': // activate debug mode
-            Options.setSystem(StaticOptions.DEBUG, true);
+            Prop.put(StaticOptions.DEBUG, true);
             Prop.debug = true;
             break;
           case 'D': // hidden flag: daemon mode
             serve = false;
             break;
-          case 'e': // parse event port
-            Options.setSystem(StaticOptions.EVENTPORT, arg.number());
-            break;
           case 'h': // parse HTTP port
             httpPort = arg.number();
             break;
           case 'l': // use local mode
-            Options.setSystem(StaticOptions.HTTPLOCAL, true);
+            Prop.put(StaticOptions.HTTPLOCAL, true);
             break;
           case 'n': // parse host name
             final String n = arg.string();
-            Options.setSystem(StaticOptions.HOST, n);
-            Options.setSystem(StaticOptions.SERVERHOST, n);
+            Prop.put(StaticOptions.HOST, n);
+            Prop.put(StaticOptions.SERVERHOST, n);
             break;
           case 'p': // parse server port
             final int p = arg.number();
-            Options.setSystem(StaticOptions.PORT, p);
-            Options.setSystem(StaticOptions.SERVERPORT, p);
+            Prop.put(StaticOptions.PORT, p);
+            Prop.put(StaticOptions.SERVERPORT, p);
             break;
           case 'P': // specify password
-            Options.setSystem(StaticOptions.PASSWORD, arg.string());
+            Prop.put(StaticOptions.PASSWORD, arg.string());
             break;
           case 's': // parse stop port
-            Options.setSystem(StaticOptions.STOPPORT, arg.number());
+            Prop.put(StaticOptions.STOPPORT, arg.number());
             break;
           case 'S': // set service flag
             service = serve;
             break;
           case 'U': // specify user name
-            Options.setSystem(StaticOptions.USER, arg.string());
+            Prop.put(StaticOptions.USER, arg.string());
             break;
           case 'z': // suppress logging
-            Options.setSystem(StaticOptions.LOG, false);
+            Prop.put(StaticOptions.LOG, false);
             break;
           default:
             throw arg.usage();
@@ -336,7 +331,7 @@
       if(ping(S_LOCALHOST, port, ssl)) return;
       Performance.sleep(c * 100L);
     }
-    throw new BaseXException(CONNECTION_ERROR);
+    throw new BaseXException(CONNECTION_ERROR_X, port);
   }
 
   /**
@@ -360,9 +355,10 @@
       new Socket(S_LOCALHOST, port).close();
       // give the notified process some time to quit
       Performance.sleep(100);
-    } catch(final IOException ex) {
+    } catch(final ConnectException ex) {
+      throw new IOException(Util.info(CONNECTION_ERROR_X, port));
+    } finally {
       stop.delete();
-      throw ex;
     }
   }
 
diff -Nru basex-8.1.1/basex-api/src/main/java/org/basex/http/HTTPCode.java basex-8.2.3/basex-api/src/main/java/org/basex/http/HTTPCode.java
--- basex-8.1.1/basex-api/src/main/java/org/basex/http/HTTPCode.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/java/org/basex/http/HTTPCode.java	2015-07-14 10:54:40.000000000 +0000
@@ -27,6 +27,8 @@
   NO_PATH(SC_NOT_FOUND, "No path specified."),
   /** Error: 404, "No function found to process the request.". */
   NO_XQUERY(SC_NOT_FOUND, "No function found that matches the request."),
+  /** Error: 404, "RESTXQ directory not found.". */
+  NO_RESTXQ(SC_NOT_FOUND, "RESTXQ directory not found."),
 
   /** Error 501, "Method not supported: %.". */
   NOT_IMPLEMENTED_X(SC_NOT_IMPLEMENTED, "Method not supported: %.");
diff -Nru basex-8.1.1/basex-api/src/main/java/org/basex/http/HTTPContext.java basex-8.2.3/basex-api/src/main/java/org/basex/http/HTTPContext.java
--- basex-8.1.1/basex-api/src/main/java/org/basex/http/HTTPContext.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/java/org/basex/http/HTTPContext.java	2015-07-14 10:54:40.000000000 +0000
@@ -24,7 +24,6 @@
 import org.basex.util.*;
 import org.basex.util.http.*;
 import org.basex.util.http.HttpText.Request;
-import org.basex.util.options.*;
 
 /**
  * Bundles context-based information on a single HTTP operation.
@@ -175,7 +174,7 @@
   }
 
   /**
-   * Returns the URL path.
+   * Returns the URL path. The path always starts with a slash.
    * @return path path
    */
   public String path() {
@@ -376,6 +375,43 @@
     context.log.write(address(), context.user(), type, info, perf);
   }
 
+  /**
+   * Sends a redirect.
+   * @param location location
+   * @throws IOException I/O exception
+   */
+  public void redirect(final String location) throws IOException {
+    res.sendRedirect(resolve(location));
+  }
+
+  /**
+   * Normalizes a redirection location. Prefixes absolute locations with the request URI.
+   * @param location location
+   * @return normalized representation
+   */
+  public String resolve(final String location) {
+    String loc = location;
+    if(location.startsWith("/")) {
+      final String uri = req.getRequestURI(), info = req.getPathInfo();
+      if(info == null) {
+        loc = uri + location;
+      } else {
+        loc = uri.substring(0, uri.length() - info.length()) + location;
+      }
+    }
+    return loc;
+  }
+
+  /**
+   * Sends a forward.
+   * @param location location
+   * @throws IOException I/O exception
+   * @throws ServletException servlet exception
+   */
+  public void forward(final String location) throws IOException, ServletException {
+    req.getRequestDispatcher(resolve(location)).forward(req, res);
+  }
+
   // STATIC METHODS =====================================================================
 
   /**
@@ -400,8 +436,8 @@
 
     // set web application path as home directory and HTTPPATH
     final String webapp = sc.getRealPath("/");
-    Options.setSystem(Prop.PATH, webapp);
-    Options.setSystem(StaticOptions.WEBPATH, webapp);
+    System.setProperty(Prop.PATH, webapp);
+    Prop.put(StaticOptions.WEBPATH, webapp);
 
     // bind all parameters that start with "org.basex." to system properties
     final Enumeration<String> en = sc.getInitParameterNames();
@@ -415,7 +451,7 @@
         Util.debug(key.toUpperCase(Locale.ENGLISH) + ": " + val);
         val = new IOFile(webapp, val).path();
       }
-      Options.setSystem(key, val);
+      Prop.put(key, val);
     }
 
     // create context, update options
@@ -441,13 +477,15 @@
    * Closes the database context.
    */
   public static synchronized void close() {
-    if(server == null) return;
-    try {
-      server.stop();
-    } catch(final IOException ex) {
-      Util.stack(ex);
+    if(server != null) {
+      try {
+        server.stop();
+      } catch(final IOException ex) {
+        Util.stack(ex);
+      }
+      server = null;
     }
-    server = null;
+    context.close();
   }
 
   /**
diff -Nru basex-8.1.1/basex-api/src/main/java/org/basex/http/HTTPParams.java basex-8.2.3/basex-api/src/main/java/org/basex/http/HTTPParams.java
--- basex-8.1.1/basex-api/src/main/java/org/basex/http/HTTPParams.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/java/org/basex/http/HTTPParams.java	2015-07-14 10:54:40.000000000 +0000
@@ -9,7 +9,6 @@
 import org.basex.io.*;
 import org.basex.io.in.*;
 import org.basex.query.*;
-import org.basex.query.iter.*;
 import org.basex.query.value.*;
 import org.basex.query.value.item.*;
 import org.basex.util.*;
@@ -89,7 +88,7 @@
       for(final Entry<String, String[]> entry : map().entrySet()) {
         final String key = entry.getKey();
         final String[] values = entry.getValue();
-        final ValueBuilder vb = new ValueBuilder(values.length);
+        final ValueBuilder vb = new ValueBuilder();
         for(final String v : values) vb.add(new Atm(v));
         query.put(key, vb.value());
       }
diff -Nru basex-8.1.1/basex-api/src/main/java/org/basex/http/restxq/RestXqFunction.java basex-8.2.3/basex-api/src/main/java/org/basex/http/restxq/RestXqFunction.java
--- basex-8.1.1/basex-api/src/main/java/org/basex/http/restxq/RestXqFunction.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/java/org/basex/http/restxq/RestXqFunction.java	2015-07-14 10:54:40.000000000 +0000
@@ -18,14 +18,15 @@
 import org.basex.build.json.*;
 import org.basex.build.text.*;
 import org.basex.core.*;
+import org.basex.core.Context;
 import org.basex.http.*;
 import org.basex.io.serial.*;
 import org.basex.query.*;
+import org.basex.query.ann.*;
 import org.basex.query.expr.*;
 import org.basex.query.expr.path.*;
 import org.basex.query.expr.path.Test.Kind;
 import org.basex.query.func.*;
-import org.basex.query.iter.*;
 import org.basex.query.util.*;
 import org.basex.query.value.*;
 import org.basex.query.value.item.*;
@@ -114,65 +115,68 @@
 
   /**
    * Checks a function for RESTFful annotations.
-   * @param http HTTP context
+   * @param ctx database context
    * @return {@code true} if module contains relevant annotations
    * @throws Exception exception
    */
-  boolean parse(final HTTPContext http) throws Exception {
+  boolean parse(final Context ctx) throws Exception {
     // parse all annotations
     final boolean[] declared = new boolean[function.args.length];
     boolean found = false;
-    final MainOptions options = http.context(false).options;
+    final MainOptions options = ctx.options;
     for(final Ann ann : function.anns) {
-      found |= eq(ann.sig.uri, QueryText.REST_URI);
-      if(ann.sig == _REST_PATH) {
+      final Annotation sig = ann.sig;
+      if(sig == null) continue;
+
+      found |= eq(sig.uri, QueryText.REST_URI);
+      if(sig == _REST_PATH) {
         try {
           path = new RestXqPath(toString(ann.args[0]), ann.info);
         } catch(final IllegalArgumentException ex) {
           throw error(ann.info, ex.getMessage());
         }
         for(final QNm v : path.vars()) checkVariable(v, AtomType.AAT, declared);
-      } else if(ann.sig == _REST_ERROR) {
+      } else if(sig == _REST_ERROR) {
         error(ann);
-      } else if(ann.sig == _REST_CONSUMES) {
+      } else if(sig == _REST_CONSUMES) {
         strings(ann, consumes);
-      } else if(ann.sig == _REST_PRODUCES) {
+      } else if(sig == _REST_PRODUCES) {
         strings(ann, produces);
-      } else if(ann.sig == _REST_QUERY_PARAM) {
+      } else if(sig == _REST_QUERY_PARAM) {
         queryParams.add(param(ann, declared));
-      } else if(ann.sig == _REST_FORM_PARAM) {
+      } else if(sig == _REST_FORM_PARAM) {
         formParams.add(param(ann, declared));
-      } else if(ann.sig == _REST_HEADER_PARAM) {
+      } else if(sig == _REST_HEADER_PARAM) {
         headerParams.add(param(ann, declared));
-      } else if(ann.sig == _REST_COOKIE_PARAM) {
+      } else if(sig == _REST_COOKIE_PARAM) {
         cookieParams.add(param(ann, declared));
-      } else if(ann.sig == _REST_ERROR_PARAM) {
+      } else if(sig == _REST_ERROR_PARAM) {
         errorParams.add(param(ann, declared));
-      } else if(ann.sig == _REST_METHOD) {
+      } else if(sig == _REST_METHOD) {
         final String mth = toString(ann.args[0]).toUpperCase(Locale.ENGLISH);
         final Item body = ann.args.length > 1 ? ann.args[1] : null;
         addMethod(mth, body, declared, ann.info);
-      } else if(eq(ann.sig.uri, QueryText.REST_URI)) {
+      } else if(eq(sig.uri, QueryText.REST_URI)) {
         final Item body = ann.args.length == 0 ? null : ann.args[0];
-        addMethod(string(ann.sig.local()), body, declared, ann.info);
-      } else if(ann.sig == _INPUT_CSV) {
+        addMethod(string(sig.local()), body, declared, ann.info);
+      } else if(sig == _INPUT_CSV) {
         final CsvParserOptions opts = new CsvParserOptions(options.get(MainOptions.CSVPARSER));
         options.set(MainOptions.CSVPARSER, parse(opts, ann));
-      } else if(ann.sig == _INPUT_JSON) {
+      } else if(sig == _INPUT_JSON) {
         final JsonParserOptions opts = new JsonParserOptions(options.get(MainOptions.JSONPARSER));
         options.set(MainOptions.JSONPARSER, parse(opts, ann));
-      } else if(ann.sig == _INPUT_HTML) {
+      } else if(sig == _INPUT_HTML) {
         final HtmlOptions opts = new HtmlOptions(options.get(MainOptions.HTMLPARSER));
         options.set(MainOptions.HTMLPARSER, parse(opts, ann));
-      } else if(ann.sig == _INPUT_TEXT) {
+      } else if(sig == _INPUT_TEXT) {
         final TextOptions opts = new TextOptions(options.get(MainOptions.TEXTPARSER));
         options.set(MainOptions.TEXTPARSER, parse(opts, ann));
-      } else if(eq(ann.sig.uri, QueryText.OUTPUT_URI)) {
+      } else if(eq(sig.uri, QueryText.OUTPUT_URI)) {
         // serialization parameters
         try {
-          output.assign(string(ann.sig.local()), toString(ann.args[0]));
+          output.assign(string(sig.local()), toString(ann.args[0]));
         } catch(final BaseXException ex) {
-          throw error(ann.info, UNKNOWN_SER, ann.sig.local());
+          throw error(ann.info, UNKNOWN_SER, sig.local());
         }
       }
     }
@@ -498,7 +502,7 @@
     final QNm qnm = checkVariable(toString(args[1]), declared);
     // default value
     final int al = args.length;
-    final ValueBuilder vb = new ValueBuilder(al);
+    final ValueBuilder vb = new ValueBuilder();
     for(int a = 2; a < al; a++) vb.add(args[a]);
     return new RestXqParam(qnm, key, vb.value());
   }
diff -Nru basex-8.1.1/basex-api/src/main/java/org/basex/http/restxq/RestXqModule.java basex-8.2.3/basex-api/src/main/java/org/basex/http/restxq/RestXqModule.java
--- basex-8.1.1/basex-api/src/main/java/org/basex/http/restxq/RestXqModule.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/java/org/basex/http/restxq/RestXqModule.java	2015-07-14 10:54:40.000000000 +0000
@@ -6,6 +6,7 @@
 import java.io.*;
 import java.util.*;
 
+import org.basex.core.*;
 import org.basex.http.*;
 import org.basex.io.*;
 import org.basex.query.*;
@@ -44,14 +45,15 @@
     functions.clear();
 
     // loop through all functions
-    try(final QueryContext qc = qc(http)) {
+    final Context ctx = http.context(false);
+    try(final QueryContext qc = qc(ctx)) {
       // loop through all functions
       final String name = file.name();
       for(final StaticFunc uf : qc.funcs.funcs()) {
         // only add functions that are defined in the same module (file)
         if(name.equals(new IOFile(uf.info.path()).name())) {
           final RestXqFunction rxf = new RestXqFunction(uf, qc, this);
-          if(rxf.parse(http)) functions.add(rxf);
+          if(rxf.parse(ctx)) functions.add(rxf);
         }
       }
     }
@@ -92,9 +94,10 @@
       throws Exception {
 
     // create new XQuery instance
-    try(final QueryContext qc = qc(http)) {
+    final Context ctx = http.context(false);
+    try(final QueryContext qc = qc(ctx)) {
       final RestXqFunction rxf = new RestXqFunction(find(qc, func.function), qc, this);
-      rxf.parse(http);
+      rxf.parse(ctx);
       RestXqResponse.create(rxf, qc, http, error);
     }
   }
@@ -103,12 +106,12 @@
 
   /**
    * Retrieves a query context for the given module.
-   * @param http HTTP context
+   * @param ctx database context
    * @return query context
    * @throws Exception exception
    */
-  private QueryContext qc(final HTTPContext http) throws Exception {
-    final QueryContext qc = new QueryContext(http.context(false));
+  private QueryContext qc(final Context ctx) throws Exception {
+    final QueryContext qc = new QueryContext(ctx);
     try {
       qc.parse(string(file.read()), file.path(), null);
       return qc;
diff -Nru basex-8.1.1/basex-api/src/main/java/org/basex/http/restxq/RestXqModules.java basex-8.2.3/basex-api/src/main/java/org/basex/http/restxq/RestXqModules.java
--- basex-8.1.1/basex-api/src/main/java/org/basex/http/restxq/RestXqModules.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/java/org/basex/http/restxq/RestXqModules.java	2015-07-14 10:54:40.000000000 +0000
@@ -24,8 +24,6 @@
 
   /** Module cache. */
   private HashMap<String, RestXqModule> modules = new HashMap<>();
-  /** RESTXQ path. */
-  private IOFile restxq;
   /** Private constructor. */
   private RestXqModules() { }
 
@@ -38,6 +36,13 @@
   }
 
   /**
+   * Initializes the module cache.
+   */
+  public void init() {
+    modules = new HashMap<>();
+  }
+
+  /**
    * Returns a WADL description for all available URIs.
    * @param http HTTP context
    * @return WADL description
@@ -55,11 +60,9 @@
    * @throws Exception exception (including unexpected ones)
    */
   RestXqFunction find(final HTTPContext http, final QNm error) throws Exception {
-    cache(http);
-
     // collect all functions
     final ArrayList<RestXqFunction> list = new ArrayList<>();
-    for(final RestXqModule mod : modules.values()) {
+    for(final RestXqModule mod : cache(http).values()) {
       for(final RestXqFunction rxf : mod.functions()) {
         if(rxf.matches(http, error)) list.add(rxf);
       }
@@ -128,20 +131,27 @@
   /**
    * Updates the module cache. Parses new modules and discards obsolete ones.
    * @param http http context
+   * @return module cache
    * @throws Exception exception (including unexpected ones)
    */
-  private synchronized void cache(final HTTPContext http) throws Exception {
-    // initialize RESTXQ directory (may be relative against WEBPATH)
-    if(restxq == null) {
-      final StaticOptions sopts = http.context(false).soptions;
+  private synchronized HashMap<String, RestXqModule> cache(final HTTPContext http)
+      throws Exception {
+
+    final StaticOptions sopts = http.context(false).soptions;
+    HashMap<String, RestXqModule> cache = modules;
+
+    // create new cache if it is empty, or if cache is to be recreated every time
+    if(cache.isEmpty() || !sopts.get(StaticOptions.CACHERESTXQ)) {
+      cache = new HashMap<>();
       final String webpath = sopts.get(StaticOptions.WEBPATH);
       final String rxqpath = sopts.get(StaticOptions.RESTXQPATH);
-      restxq = new IOFile(webpath).resolve(rxqpath);
+      final IOFile restxq = new IOFile(webpath).resolve(rxqpath);
+      if(!restxq.exists()) throw HTTPCode.NO_RESTXQ.get();
+
+      cache(http, restxq, cache, modules);
+      modules = cache;
     }
-    // create new cache
-    final HashMap<String, RestXqModule> cache = new HashMap<>();
-    cache(http, restxq, cache);
-    modules = cache;
+    return cache;
   }
 
   /**
@@ -149,18 +159,24 @@
    * @param root root path
    * @param http http context
    * @param cache cached modules
+   * @param old old cache
    * @throws Exception exception (including unexpected ones)
    */
-  private synchronized void cache(final HTTPContext http, final IOFile root,
-      final HashMap<String, RestXqModule> cache) throws Exception {
+  private static synchronized void cache(final HTTPContext http, final IOFile root,
+      final HashMap<String, RestXqModule> cache, final HashMap<String, RestXqModule> old)
+      throws Exception {
+
+    // check if directory is to be skipped
+    final IOFile[] files = root.children();
+    for(final IOFile file : files) if(file.name().equals(IGNORE)) return;
 
-    for(final IOFile file : root.children()) {
+    for(final IOFile file : files) {
       if(file.isDir()) {
-        cache(http, file, cache);
+        cache(http, file, cache, old);
       } else {
         final String path = file.path();
         if(file.hasSuffix(IO.XQSUFFIXES)) {
-          RestXqModule module = modules.get(path);
+          RestXqModule module = old.get(path);
           boolean parsed = false;
           if(module != null) {
             // check if module has been modified
diff -Nru basex-8.1.1/basex-api/src/main/java/org/basex/http/restxq/RestXqRespBuilder.java basex-8.2.3/basex-api/src/main/java/org/basex/http/restxq/RestXqRespBuilder.java
--- basex-8.1.1/basex-api/src/main/java/org/basex/http/restxq/RestXqRespBuilder.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/java/org/basex/http/restxq/RestXqRespBuilder.java	2015-07-14 10:54:40.000000000 +0000
@@ -67,12 +67,12 @@
             final byte[] nam = c.attribute(Q_NAME);
             final byte[] val = c.attribute(Q_VALUE);
             if(nam != null && val != null) {
-              final String key = string(nam);
-              final String value = string(val);
-              if(key.equals(HttpText.CONTENT_TYPE)) {
+              final String key = string(nam), value = string(val);
+              if(key.equalsIgnoreCase(HttpText.CONTENT_TYPE)) {
                 cType = value;
               } else {
-                http.res.setHeader(key, value);
+                http.res.setHeader(key, key.equalsIgnoreCase(HttpText.LOCATION) ?
+                  http.resolve(value) : value);
               }
             }
           } else {
diff -Nru basex-8.1.1/basex-api/src/main/java/org/basex/http/restxq/RestXqResponse.java basex-8.2.3/basex-api/src/main/java/org/basex/http/restxq/RestXqResponse.java
--- basex-8.1.1/basex-api/src/main/java/org/basex/http/restxq/RestXqResponse.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/java/org/basex/http/restxq/RestXqResponse.java	2015-07-14 10:54:40.000000000 +0000
@@ -96,9 +96,9 @@
       query.context.unregister(query);
 
       if(redirect != null) {
-        http.res.sendRedirect(redirect);
+        http.redirect(redirect);
       } else if(forward != null) {
-        http.req.getRequestDispatcher(forward).forward(http.req, http.res);
+        http.forward(forward);
       } else if(response != null) {
         if(response.status != 0) http.status(response.status, response.message, response.error);
         final byte[] out = response.cache.finish();
diff -Nru basex-8.1.1/basex-api/src/main/java/org/basex/http/restxq/RestXqServlet.java basex-8.2.3/basex-api/src/main/java/org/basex/http/restxq/RestXqServlet.java
--- basex-8.1.1/basex-api/src/main/java/org/basex/http/restxq/RestXqServlet.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/java/org/basex/http/restxq/RestXqServlet.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,5 +1,7 @@
 package org.basex.http.restxq;
 
+import static org.basex.http.restxq.RestXqText.*;
+
 import org.basex.http.*;
 import org.basex.query.*;
 
@@ -18,17 +20,30 @@
 public final class RestXqServlet extends BaseXServlet {
   @Override
   protected void run(final HTTPContext http) throws Exception {
+    // no trailing slash: send redirect
+    if(http.req.getPathInfo() == null) {
+      http.redirect("/");
+      return;
+    }
+
     // analyze input path
     final RestXqModules rxm = RestXqModules.get();
-    // select XQuery function
+
+    // initialize RESTXQ
+    if(http.path().equals("/" + INIT)) {
+      rxm.init();
+      return;
+    }
+
+    // select function that closest matches the request
     RestXqFunction func = rxm.find(http, null);
     if(func == null) throw HTTPCode.NO_XQUERY.get();
 
     try {
-      // process function that matches the current request
+      // process function
       func.process(http, null);
     } catch(final QueryException ex) {
-      // process optional error function
+      // run optional error function
       func = rxm.find(http, ex.qname());
       if(func == null) throw ex;
       func.process(http, ex);
diff -Nru basex-8.1.1/basex-api/src/main/java/org/basex/http/restxq/RestXqText.java basex-8.2.3/basex-api/src/main/java/org/basex/http/restxq/RestXqText.java
--- basex-8.1.1/basex-api/src/main/java/org/basex/http/restxq/RestXqText.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/java/org/basex/http/restxq/RestXqText.java	2015-07-14 10:54:40.000000000 +0000
@@ -44,6 +44,10 @@
   String WADL_URI = "http://wadl.dev.java.net/2009/02";
   /** XHTML namespace. */
   String XHTML_URL = "http://www.w3.org/1999/xhtml";
+  /** Ignore directory. */
+  String IGNORE = ".ignore";
+  /** Init call. */
+  String INIT = ".init";
 
   /** Error message. */
   String ANN_MISSING = "Annotation %% or %% missing.";
diff -Nru basex-8.1.1/basex-api/src/main/java/org/basex/http/ServletListener.java basex-8.2.3/basex-api/src/main/java/org/basex/http/ServletListener.java
--- basex-8.1.1/basex-api/src/main/java/org/basex/http/ServletListener.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/java/org/basex/http/ServletListener.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,15 +1,13 @@
 package org.basex.http;
 
 import javax.servlet.*;
-import javax.servlet.annotation.*;
 
 /**
- * <p>Servlet listener.</p>
+ * This class creates and destroys servlet contexts.
  *
  * @author BaseX Team 2005-15, BSD License
  * @author Christian Gruen
  */
-@WebListener
 public final class ServletListener implements ServletContextListener {
   @Override
   public void contextInitialized(final ServletContextEvent event) {
diff -Nru basex-8.1.1/basex-api/src/main/java/org/basex/http/SessionListener.java basex-8.2.3/basex-api/src/main/java/org/basex/http/SessionListener.java
--- basex-8.1.1/basex-api/src/main/java/org/basex/http/SessionListener.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/java/org/basex/http/SessionListener.java	2015-07-14 10:54:40.000000000 +0000
@@ -5,7 +5,7 @@
 import javax.servlet.http.*;
 
 /**
- * This class bundles context-based information on a single HTTP operation.
+ * This class creates and destroys HTTP sessions.
  *
  * @author BaseX Team 2005-15, BSD License
  * @author Christian Gruen
diff -Nru basex-8.1.1/basex-api/src/main/java/org/basex/http/webdav/impl/WebDAVService.java basex-8.2.3/basex-api/src/main/java/org/basex/http/webdav/impl/WebDAVService.java
--- basex-8.1.1/basex-api/src/main/java/org/basex/http/webdav/impl/WebDAVService.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/java/org/basex/http/webdav/impl/WebDAVService.java	2015-07-14 10:54:40.000000000 +0000
@@ -4,7 +4,6 @@
 import static org.basex.query.func.Function.*;
 
 import java.io.*;
-import java.text.*;
 import java.util.*;
 import java.util.Map.Entry;
 import java.util.List;
@@ -114,14 +113,7 @@
   public long timestamp(final String db) throws IOException {
     final WebDAVQuery query = new WebDAVQuery(DATA.args(_DB_INFO.args("$path") +
         "/descendant::" + DbFn.toName(Text.TIMESTAMP) + "[1]")).bind("path",  db);
-
-    try {
-      // retrieve and parse timestamp
-      return DateTime.parse(execute(query).get(0), DateTime.DATETIME).getTime();
-    } catch(final ParseException ex) {
-      Util.errln(ex);
-      return 0L;
-    }
+    return DateTime.parse(execute(query).get(0)).getTime();
   }
 
   /**
@@ -146,7 +138,7 @@
     final StringList result = execute(query);
     final boolean raw = Boolean.parseBoolean(result.get(0));
     final MediaType type = new MediaType(result.get(1));
-    final long mod = DateTime.parse(result.get(2));
+    final long mod = DateTime.parse(result.get(2)).getTime();
     final Long size = raw ? Long.valueOf(result.get(3)) : null;
     final String pth = stripLeadingSlash(result.get(4));
     return new ResourceMetaData(db, pth, mod, raw, type, size);
@@ -320,7 +312,7 @@
     for(int r = 0; r < rs; r += 5) {
       final boolean raw = Boolean.parseBoolean(result.get(r));
       final MediaType ctype = new MediaType(result.get(r + 1));
-      final long mod = DateTime.parse(result.get(r + 2));
+      final long mod = DateTime.parse(result.get(r + 2)).getTime();
       final Long size = raw ? Long.valueOf(result.get(r + 3)) : null;
       final String pth = stripLeadingSlash(result.get(r + 4));
       final int ix = pth.indexOf(SEP);
@@ -351,7 +343,7 @@
     final List<T> dbs = new ArrayList<>(rs >>> 1);
     for(int r = 0; r < rs; r += 2) {
       final String name = result.get(r);
-      final long mod = DateTime.parse(result.get(r + 1));
+      final long mod = DateTime.parse(result.get(r + 1)).getTime();
       dbs.add(factory.database(this, new ResourceMetaData(name, mod)));
     }
     return dbs;
diff -Nru basex-8.1.1/basex-api/src/main/java/org/basex/modules/Session.java basex-8.2.3/basex-api/src/main/java/org/basex/modules/Session.java
--- basex-8.1.1/basex-api/src/main/java/org/basex/modules/Session.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/java/org/basex/modules/Session.java	2015-07-14 10:54:40.000000000 +0000
@@ -7,7 +7,6 @@
 import org.basex.data.*;
 import org.basex.http.*;
 import org.basex.query.*;
-import org.basex.query.iter.*;
 import org.basex.query.value.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.node.*;
@@ -99,7 +98,7 @@
    */
   @Requires(Permission.NONE)
   public void set(final Str key, final Value value) throws QueryException {
-    final ValueBuilder vb = new ValueBuilder(Math.max(1, (int) value.size()));
+    final ValueBuilder vb = new ValueBuilder();
     for(final Item item : value) {
       if(item instanceof FItem) throw SessionErrors.functionItem();
       final Data d = item.data();
diff -Nru basex-8.1.1/basex-api/src/main/java/org/exquery/ns/Request.java basex-8.2.3/basex-api/src/main/java/org/exquery/ns/Request.java
--- basex-8.1.1/basex-api/src/main/java/org/exquery/ns/Request.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/java/org/exquery/ns/Request.java	2015-07-14 10:54:40.000000000 +0000
@@ -7,7 +7,6 @@
 
 import org.basex.http.*;
 import org.basex.query.*;
-import org.basex.query.iter.*;
 import org.basex.query.value.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.seq.*;
diff -Nru basex-8.1.1/basex-api/src/main/python3/BaseXClient.py basex-8.2.3/basex-api/src/main/python3/BaseXClient.py
--- basex-8.1.1/basex-api/src/main/python3/BaseXClient.py	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/python3/BaseXClient.py	2015-07-14 10:54:40.000000000 +0000
@@ -112,11 +112,6 @@
 
         self.__swrapper.connect((host, port))
 
-        self.__event_socket_wrapper = None
-        self.__event_host = host
-        self.__event_listening_thread = None
-        self.__event_callbacks = {}
-
         # receive timestamp
         response = self.recv_c_str().split(':')
 
@@ -185,76 +180,6 @@
         """Close the session"""
         self.send('exit')
         self.__swrapper.close()
-        if not self.__event_socket_wrapper is None:
-            self.__event_socket_wrapper.close()
-
-    def __register_and_start_listener(self,
-                                      receive_bytes_encoding=None,
-                                      send_bytes_encoding=None):
-        """register and start listener."""
-
-        if receive_bytes_encoding:
-            receive_bytes_encoding_ = receive_bytes_encoding
-        else:
-            receive_bytes_encoding_ = self.__swrapper.receive_bytes_encoding
-        if send_bytes_encoding:
-            send_bytes_encoding_ = send_bytes_encoding
-        else:
-            send_bytes_encoding_ = self.__swrapper.send_bytes_encoding
-
-        self.__swrapper.sendall(chr(10))
-        event_port = int(self.recv_c_str())
-        self.__event_socket_wrapper = SocketWrapper(
-            socket.socket(socket.AF_INET, socket.SOCK_STREAM),
-            receive_bytes_encoding=receive_bytes_encoding_,
-            send_bytes_encoding=send_bytes_encoding_)
-        self.__event_socket_wrapper.settimeout(5000)
-        self.__event_socket_wrapper.connect((self.__event_host, event_port))
-        token = self.recv_c_str()
-        self.__event_socket_wrapper.sendall(token + chr(0))
-        #if self.__event_socket_wrapper.recv_single_byte() != chr(0):
-        #    raise IOError("Could not register event listener")
-        #java example client does skip next byte...
-        ign = self.__event_socket_wrapper.recv_single_byte()
-
-        self.__event_listening_thread = threading.Thread(
-            target=self.__event_listening_loop
-        )
-        self.__event_listening_thread.daemon = True
-        self.__event_listening_thread.start()
-
-    def __event_listening_loop(self):
-        """event listening loop (in subthread)"""
-        reader = self.__event_socket_wrapper
-        reader.clear_buffer()
-        while True:
-            name = reader.recv_until_terminator()
-            data = reader.recv_until_terminator()
-            self.__event_callbacks[name](data)
-
-    def is_listening(self):
-        """true if registered and started listener, false otherwise"""
-        return not self.__event_socket_wrapper is None
-
-    def watch(self, name, callback):
-        """Watch the specified event"""
-        if not self.is_listening():
-            self.__register_and_start_listener()
-        else:
-            self.__swrapper.sendall(chr(10))
-        self.send(name)
-        info = self.recv_c_str()
-        if not self.server_response_success():
-            raise IOError(info)
-        self.__event_callbacks[name] = callback
-
-    def unwatch(self, name):
-        """Unwatch the specified event"""
-        self.send(chr(11) + name)
-        info = self.recv_c_str()
-        if not self.server_response_success():
-            raise IOError(info)
-        del self.__event_callbacks[name]
 
     def recv_c_str(self):
         """Retrieve a string from the socket"""
diff -Nru basex-8.1.1/basex-api/src/main/python3/WatchEventExample.py basex-8.2.3/basex-api/src/main/python3/WatchEventExample.py
--- basex-8.1.1/basex-api/src/main/python3/WatchEventExample.py	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/python3/WatchEventExample.py	1970-01-01 00:00:00.000000000 +0000
@@ -1,60 +0,0 @@
-# -*- coding: utf-8 -*-
-# Documentation: http://docs.basex.org/wiki/Events
-#
-# (C) BaseX Team 2005-12, BSD License
-
-import BaseXClient
-import time
-from datetime import datetime
-from multiprocessing import Process
-
-# event publisher process (child)
-def child():
-    # create session (listener)
-    session = BaseXClient.Session('localhost', 1984, 'admin', 'admin')
-
-    # trigger event (first)
-    session.execute("""xquery db:event("MY_EVENT", "fired MY_EVENT from child, at %s")""" % str(datetime.now()))
-
-    # Zzz...
-    time.sleep(3)
-
-    # trigger event (second)
-    session.execute("""xquery db:event("MY_EVENT", "fired MY_EVENT from child, at %s")""" % str(datetime.now()))
-
-    # close session
-    session.close()
-
-# listener function
-def dump_my_event(data):
-    print(data)
-
-# listener process main
-def main():
-    # create session (listener)
-    session = BaseXClient.Session('localhost', 1984, 'admin', 'admin')
-
-    # create event
-    session.execute("create event MY_EVENT");
-
-    try:
-        # register event watcher
-        session.watch("MY_EVENT", dump_my_event)
-
-        # fork child
-        chp = Process(target=child, args=())
-        chp.start()
-        chp.join()
-
-        # unregister event watcher
-        session.unwatch("MY_EVENT")
-
-    finally:
-        # drop event
-        session.execute("drop event MY_EVENT");
-
-    # close session
-    session.close()
-
-# test it!
-main()
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/common.xqm basex-8.2.3/basex-api/src/main/webapp/dba/common.xqm
--- basex-8.1.1/basex-api/src/main/webapp/dba/common.xqm	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/common.xqm	2015-07-14 10:54:40.000000000 +0000
@@ -13,10 +13,10 @@
  : Redirects to the start page.
  :)
 declare
-  %rest:path("dba")
+  %rest:path("/dba")
 function _:redirect(
 ) {
-  web:redirect('dba/databases')
+  web:redirect("/dba/databases")
 };
 
 (:~
@@ -25,11 +25,11 @@
  : @return rest response and binary file
  :)
 declare
-  %rest:path("dba/files/{$file=.+}")
+  %rest:path("/dba/static/{$file=.+}")
 function _:file(
   $file as xs:string
 ) as item()+ {
-  let $path := file:base-dir() || 'files/' || $file
+  let $path := file:base-dir() || 'static/' || $file
   return (
     web:response-header(map { 'media-type': web:content-type($path) }),
     file:read-binary($path)
@@ -42,7 +42,7 @@
  : @return page
  :)
 declare
-  %rest:path("dba/{$unknown}")
+  %rest:path("/dba/{$unknown}")
   %output:method("html")
 function _:any(
   $unknown  as xs:string
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/databases/alter-db.xqm basex-8.2.3/basex-api/src/main/webapp/dba/databases/alter-db.xqm
--- basex-8.1.1/basex-api/src/main/webapp/dba/databases/alter-db.xqm	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/databases/alter-db.xqm	2015-07-14 10:54:40.000000000 +0000
@@ -24,7 +24,7 @@
  :)
 declare
   %rest:GET
-  %rest:path("dba/alter-db")
+  %rest:path("/dba/alter-db")
   %rest:query-param("name",    "{$name}")
   %rest:query-param("newname", "{$newname}")
   %rest:query-param("error",   "{$error}")
@@ -70,7 +70,7 @@
 declare
   %updating
   %rest:POST
-  %rest:path("dba/alter-db")
+  %rest:path("/dba/alter-db")
   %rest:query-param("name",    "{$name}")
   %rest:query-param("newname", "{$newname}")
 function _:alter(
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/databases/backups.xqm basex-8.2.3/basex-api/src/main/webapp/dba/databases/backups.xqm
--- basex-8.1.1/basex-api/src/main/webapp/dba/databases/backups.xqm	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/databases/backups.xqm	2015-07-14 10:54:40.000000000 +0000
@@ -18,7 +18,7 @@
 declare
   %updating
   %rest:GET
-  %rest:path("dba/create-backup")
+  %rest:path("/dba/create-backup")
   %rest:query-param("name", "{$name}")
 function _:create-backup(
   $name  as xs:string
@@ -34,7 +34,7 @@
 declare
   %updating
   %rest:GET
-  %rest:path("dba/drop-backup")
+  %rest:path("/dba/drop-backup")
   %rest:query-param("name",   "{$name}")
   %rest:query-param("backup", "{$backups}")
 function _:drop-backup(
@@ -54,7 +54,7 @@
 declare
   %updating
   %rest:GET
-  %rest:path("dba/restore")
+  %rest:path("/dba/restore")
   %rest:query-param("name",   "{$name}")
   %rest:query-param("backup", "{$backup}")
 function _:restore(
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/databases/copy.xqm basex-8.2.3/basex-api/src/main/webapp/dba/databases/copy.xqm
--- basex-8.1.1/basex-api/src/main/webapp/dba/databases/copy.xqm	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/databases/copy.xqm	2015-07-14 10:54:40.000000000 +0000
@@ -24,7 +24,7 @@
  :)
 declare
   %rest:GET
-  %rest:path("dba/copy")
+  %rest:path("/dba/copy")
   %rest:query-param("name",    "{$name}")
   %rest:query-param("newname", "{$newname}")
   %rest:query-param("error",   "{$error}")
@@ -70,7 +70,7 @@
 declare
   %updating
   %rest:POST
-  %rest:path("dba/copy")
+  %rest:path("/dba/copy")
   %rest:query-param("name",    "{$name}")
   %rest:query-param("newname", "{$newname}")
 function _:copy(
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/databases/create-db.xqm basex-8.2.3/basex-api/src/main/webapp/dba/databases/create-db.xqm
--- basex-8.1.1/basex-api/src/main/webapp/dba/databases/create-db.xqm	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/databases/create-db.xqm	2015-07-14 10:54:40.000000000 +0000
@@ -25,7 +25,7 @@
  :)
 declare
   %rest:GET
-  %rest:path("dba/create-db")
+  %rest:path("/dba/create-db")
   %rest:query-param("name",  "{$name}")
   %rest:query-param("opts",  "{$opts}", "textindex", "attrindex")
   %rest:query-param("lang",  "{$lang}", "en")
@@ -93,7 +93,7 @@
 declare
   %updating
   %rest:POST
-  %rest:path("dba/create-db")
+  %rest:path("/dba/create-db")
   %rest:query-param("name", "{$name}")
   %rest:query-param("opts", "{$opts}")
   %rest:query-param("lang", "{$lang}")
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/databases/databases.xqm basex-8.2.3/basex-api/src/main/webapp/dba/databases/databases.xqm
--- basex-8.1.1/basex-api/src/main/webapp/dba/databases/databases.xqm	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/databases/databases.xqm	2015-07-14 10:54:40.000000000 +0000
@@ -22,7 +22,7 @@
  :)
 declare
   %rest:GET
-  %rest:path("dba/databases")
+  %rest:path("/dba/databases")
   %rest:query-param("sort",  "{$sort}", "")
   %rest:query-param("error", "{$error}")
   %rest:query-param("info",  "{$info}")
@@ -110,7 +110,7 @@
  :)
 declare
   %rest:POST
-  %rest:path("dba/databases")
+  %rest:path("/dba/databases")
   %rest:query-param("action", "{$action}")
   %rest:query-param("name",   "{$names}")
   %output:method("html")
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/databases/database.xqm basex-8.2.3/basex-api/src/main/webapp/dba/databases/database.xqm
--- basex-8.1.1/basex-api/src/main/webapp/dba/databases/database.xqm	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/databases/database.xqm	2015-07-14 10:54:40.000000000 +0000
@@ -25,7 +25,7 @@
  :)
 declare
   %rest:GET
-  %rest:path("dba/database")
+  %rest:path("/dba/database")
   %rest:query-param("name",     "{$name}")
   %rest:query-param("resource", "{$resource}")
   %rest:query-param("error",    "{$error}")
@@ -51,7 +51,7 @@
         ) else (),
         element backups { db:backups($name) }
       )
-    }', map { 'name': $name, 'max': $cons:MAX-ROWS + 1 })
+    }', map { 'name': $name, 'max': $cons:OPTION($cons:K-MAX-ROWS) + 1 })
   } catch * {
     element error { $cons:DATA-ERROR || ': ' || $err:description }
   }
@@ -71,11 +71,12 @@
               let $entries := $data/databases/* !
                 <e resource='{ . }' ct='{ @content-type }' raw='{
                   if(@raw = 'true') then '✓' else '–'
-                }'/>
+                }' size='{ @size }'/>
               let $headers := (
                 <resource>{ html:label($entries, ('Resource', 'Resources')) }</resource>,
                 <ct>Content type</ct>,
-                <raw>Raw</raw>
+                <raw>Raw</raw>,
+                <size type='number' order='desc'>Size (factor)</size>
               )
               let $buttons := (
                 html:button('add', 'Add…'),
@@ -149,7 +150,7 @@
  :)
 declare
   %rest:POST
-  %rest:path("dba/database")
+  %rest:path("/dba/database")
   %rest:form-param("action",   "{$action}")
   %rest:form-param("name",     "{$name}")
   %rest:form-param("resource", "{$resources}")
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/databases/drop-db.xqm basex-8.2.3/basex-api/src/main/webapp/dba/databases/drop-db.xqm
--- basex-8.1.1/basex-api/src/main/webapp/dba/databases/drop-db.xqm	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/databases/drop-db.xqm	2015-07-14 10:54:40.000000000 +0000
@@ -18,7 +18,7 @@
 declare
   %updating
   %rest:GET
-  %rest:path("dba/drop-db")
+  %rest:path("/dba/drop-db")
   %rest:query-param("name", "{$names}")
   %output:method("html")
 function _:drop(
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/databases/optimize.xqm basex-8.2.3/basex-api/src/main/webapp/dba/databases/optimize.xqm
--- basex-8.1.1/basex-api/src/main/webapp/dba/databases/optimize.xqm	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/databases/optimize.xqm	2015-07-14 10:54:40.000000000 +0000
@@ -26,7 +26,7 @@
  :)
 declare
   %rest:GET
-  %rest:path("dba/optimize")
+  %rest:path("/dba/optimize")
   %rest:query-param("name",  "{$name}")
   %rest:query-param("all",   "{$all}")
   %rest:query-param("opts",  "{$opts}")
@@ -108,7 +108,7 @@
 declare
   %updating
   %rest:POST
-  %rest:path("dba/optimize")
+  %rest:path("/dba/optimize")
   %rest:query-param("name", "{$name}")
   %rest:query-param("all",  "{$all}")
   %rest:query-param("opts", "{$opts}")
@@ -149,7 +149,7 @@
 declare
   %updating
   %rest:GET
-  %rest:path("dba/optimize-all")
+  %rest:path("/dba/optimize-all")
   %rest:query-param("name", "{$names}")
   %output:method("html")
 function _:drop(
@@ -157,7 +157,7 @@
 ) {
   cons:check(),
   try {
-    util:update("$names ! db:optimize(.)", map { 'n': $names }),
+    util:update("$n ! db:optimize(.)", map { 'n': $names }),
     db:output(web:redirect($_:CAT, map { 'info': 'Optimized databases: ' || count($names) }))
   } catch * {
     db:output(web:redirect($_:CAT, map { 'error': $err:description }))
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/databases/resources/add.xqm basex-8.2.3/basex-api/src/main/webapp/dba/databases/resources/add.xqm
--- basex-8.1.1/basex-api/src/main/webapp/dba/databases/resources/add.xqm	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/databases/resources/add.xqm	2015-07-14 10:54:40.000000000 +0000
@@ -25,7 +25,7 @@
  :)
 declare
   %rest:GET
-  %rest:path("dba/add")
+  %rest:path("/dba/add")
   %rest:query-param("name",     "{$name}")
   %rest:query-param("resource", "{$resource}")
   %rest:query-param("binary",   "{$binary}")
@@ -83,7 +83,7 @@
 declare
   %updating
   %rest:POST
-  %rest:path("dba/add")
+  %rest:path("/dba/add")
   %rest:form-param("name",     "{$name}")
   %rest:form-param("resource", "{$resource}")
   %rest:form-param("file",     "{$file}")
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/databases/resources/delete.xqm basex-8.2.3/basex-api/src/main/webapp/dba/databases/resources/delete.xqm
--- basex-8.1.1/basex-api/src/main/webapp/dba/databases/resources/delete.xqm	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/databases/resources/delete.xqm	2015-07-14 10:54:40.000000000 +0000
@@ -19,7 +19,7 @@
 declare
   %updating
   %rest:GET
-  %rest:path("dba/delete")
+  %rest:path("/dba/delete")
   %rest:query-param("name",     "{$name}")
   %rest:query-param("resource", "{$resources}")
   %output:method("html")
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/databases/resources/download.xqm basex-8.2.3/basex-api/src/main/webapp/dba/databases/resources/download.xqm
--- basex-8.1.1/basex-api/src/main/webapp/dba/databases/resources/download.xqm	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/databases/resources/download.xqm	2015-07-14 10:54:40.000000000 +0000
@@ -16,7 +16,7 @@
  : @return rest response and file content
  :)
 declare
-  %rest:path("dba/download/{$file}")
+  %rest:path("/dba/download/{$file}")
   %rest:query-param("name",     "{$name}")
   %rest:query-param("resource", "{$resource}")
 function _:download(
@@ -50,7 +50,7 @@
  : @return zip file
  :)
 declare
-  %rest:path("dba/backup/{$backup}")
+  %rest:path("/dba/backup/{$backup}")
   %output:method("raw")
   %output:media-type("application/octet-stream")
 function _:download(
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/databases/resources/query.xqm basex-8.2.3/basex-api/src/main/webapp/dba/databases/resources/query.xqm
--- basex-8.1.1/basex-api/src/main/webapp/dba/databases/resources/query.xqm	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/databases/resources/query.xqm	2015-07-14 10:54:40.000000000 +0000
@@ -16,11 +16,10 @@
  : @return result string
  :)
 declare
-  %rest:POST
-  %rest:path("dba/query-resource")
+  %rest:POST("{$query}")
+  %rest:path("/dba/query-resource")
   %rest:query-param("name",     "{$name}")
   %rest:query-param("resource", "{$resource}")
-  %rest:query-param("query",    "{$query}")
   %output:method("text")
 function _:query-resource(
   $name      as xs:string,
@@ -28,7 +27,6 @@
   $query     as xs:string
 ) as xs:string {
   cons:check(),
-  let $limit := $cons:MAX-CHARS
   let $query := if($query) then $query else '.'
   return util:query($query, "'': db:open($name, $resource)", map {
     'name': $name, 'resource': $resource
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/databases/resources/rename.xqm basex-8.2.3/basex-api/src/main/webapp/dba/databases/resources/rename.xqm
--- basex-8.1.1/basex-api/src/main/webapp/dba/databases/resources/rename.xqm	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/databases/resources/rename.xqm	2015-07-14 10:54:40.000000000 +0000
@@ -25,7 +25,7 @@
  :)
 declare
   %rest:GET
-  %rest:path("dba/rename")
+  %rest:path("/dba/rename")
   %rest:query-param("name",     "{$name}")
   %rest:query-param("resource", "{$resource}")
   %rest:query-param("newname",  "{$newname}")
@@ -76,7 +76,7 @@
 declare
   %updating
   %rest:POST
-  %rest:path("dba/rename")
+  %rest:path("/dba/rename")
   %rest:query-param("name",     "{$name}")
   %rest:query-param("resource", "{$resource}")
   %rest:query-param("newname",  "{$newname}")
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/databases/resources/replace.xqm basex-8.2.3/basex-api/src/main/webapp/dba/databases/resources/replace.xqm
--- basex-8.1.1/basex-api/src/main/webapp/dba/databases/resources/replace.xqm	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/databases/resources/replace.xqm	2015-07-14 10:54:40.000000000 +0000
@@ -24,7 +24,7 @@
  :)
 declare
   %rest:GET
-  %rest:path("dba/replace")
+  %rest:path("/dba/replace")
   %rest:query-param("name",     "{$name}")
   %rest:query-param("resource", "{$resource}")
   %rest:query-param("error",    "{$error}")
@@ -71,7 +71,7 @@
 declare
   %updating
   %rest:POST
-  %rest:path("dba/replace")
+  %rest:path("/dba/replace")
   %rest:form-param("name",     "{$name}")
   %rest:form-param("resource", "{$resource}")
   %rest:form-param("input",    "{$input}")
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/databases/resources/resource.xqm basex-8.2.3/basex-api/src/main/webapp/dba/databases/resources/resource.xqm
--- basex-8.1.1/basex-api/src/main/webapp/dba/databases/resources/resource.xqm	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/databases/resources/resource.xqm	2015-07-14 10:54:40.000000000 +0000
@@ -20,7 +20,7 @@
  :)
 declare
   %rest:POST
-  %rest:path("dba/resource")
+  %rest:path("/dba/resource")
   %rest:form-param("action",   "{$action}")
   %rest:form-param("name",     "{$name}")
   %rest:form-param("resource", "{$resource}")
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/files/basex.svg basex-8.2.3/basex-api/src/main/webapp/dba/files/basex.svg
--- basex-8.1.1/basex-api/src/main/webapp/dba/files/basex.svg	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/files/basex.svg	1970-01-01 00:00:00.000000000 +0000
@@ -1,78 +0,0 @@
-<?xml version="1.0" encoding="UTF-8" standalone="no"?>
-<svg
-   xmlns:dc="http://purl.org/dc/elements/1.1/"
-   xmlns:cc="http://creativecommons.org/ns#"
-   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
-   xmlns:svg="http://www.w3.org/2000/svg"
-   xmlns="http://www.w3.org/2000/svg"
-   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
-   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
-   viewBox="0 0 82.088621 73.135418"
-   height="73.135414"
-   width="82.088623"
-   xml:space="preserve"
-   version="1.1"
-   id="svg2"
-   inkscape:version="0.48.5 r10040"
-   sodipodi:docname="basex.svg"><sodipodi:namedview
-     pagecolor="#ffffff"
-     bordercolor="#666666"
-     borderopacity="1"
-     objecttolerance="10"
-     gridtolerance="10"
-     guidetolerance="10"
-     inkscape:pageopacity="0"
-     inkscape:pageshadow="2"
-     inkscape:window-width="2498"
-     inkscape:window-height="1417"
-     id="namedview3026"
-     showgrid="false"
-     fit-margin-top="1"
-     fit-margin-left="1"
-     fit-margin-right="1"
-     fit-margin-bottom="1"
-     inkscape:zoom="7.59107"
-     inkscape:cx="92.212069"
-     inkscape:cy="-8.8800238"
-     inkscape:window-x="-8"
-     inkscape:window-y="-8"
-     inkscape:window-maximized="1"
-     inkscape:current-layer="g12" /><metadata
-     id="metadata8"><rdf:RDF><cc:Work
-         rdf:about=""><dc:format>image/svg+xml</dc:format><dc:type
-           rdf:resource="http://purl.org/dc/dcmitype/StillImage" /><dc:title /></cc:Work></rdf:RDF></metadata><defs
-     id="defs6" /><g
-     transform="matrix(1.25,0,0,-1.25,-4.1804093,163.0317)"
-     id="g10"><g
-       transform="scale(0.1,0.1)"
-       id="g12"><path
-         id="path14"
-         style="fill:#4f4c4c;fill-opacity:1;fill-rule:nonzero;stroke:none"
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diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/files/config.xml basex-8.2.3/basex-api/src/main/webapp/dba/files/config.xml
--- basex-8.1.1/basex-api/src/main/webapp/dba/files/config.xml	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/files/config.xml	1970-01-01 00:00:00.000000000 +0000
@@ -1,7 +0,0 @@
-<config>
-  <maxchars>10000</maxchars>
-  <maxrows>500</maxrows>
-  <timeout>5</timeout>
-  <memory>100</memory>
-  <permission>admin</permission>
-</config>
\ No newline at end of file
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/files/delete-files.xqm basex-8.2.3/basex-api/src/main/webapp/dba/files/delete-files.xqm
--- basex-8.1.1/basex-api/src/main/webapp/dba/files/delete-files.xqm	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/files/delete-files.xqm	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,32 @@
+(:~
+ : Delete files.
+ :
+ : @author Christian Grün, BaseX GmbH, 2014-15
+ :)
+module namespace _ = 'dba/files';
+
+import module namespace cons = 'dba/cons' at '../modules/cons.xqm';
+
+(:~ Top category :)
+declare variable $_:CAT := 'files';
+
+(:~
+ : Deletes files.
+ : @param  $names  names of files
+ :)
+declare
+  %rest:GET
+  %rest:path("/dba/delete-files")
+  %rest:query-param("name", "{$names}")
+  %output:method("html")
+function _:drop(
+  $names  as xs:string*
+) {
+  cons:check(),
+  try {
+    $names ! file:delete($cons:DBA-DIR || .),
+    web:redirect($_:CAT, map { 'info': 'Deleted files: ' || count($names) })
+  } catch * {
+    web:redirect($_:CAT, map { 'error': $err:description })
+  }
+};
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/files/files.xqm basex-8.2.3/basex-api/src/main/webapp/dba/files/files.xqm
--- basex-8.1.1/basex-api/src/main/webapp/dba/files/files.xqm	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/files/files.xqm	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,107 @@
+(:~
+ : Files page.
+ :
+ : @author Christian Grün, BaseX GmbH, 2014-15
+ :)
+module namespace _ = 'dba/files';
+
+import module namespace Sessions = 'http://basex.org/modules/sessions';
+import module namespace Session = 'http://basex.org/modules/session';
+import module namespace cons = 'dba/cons' at '../modules/cons.xqm';
+import module namespace html = 'dba/html' at '../modules/html.xqm';
+import module namespace tmpl = 'dba/tmpl' at '../modules/tmpl.xqm';
+
+(:~ Top category :)
+declare variable $_:CAT := 'files';
+
+(:~
+ : Files page.
+ : @param  $sort   table sort key
+ : @param  $error  error message
+ : @param  $info   info message
+ : @return page
+ :)
+declare
+  %rest:GET
+  %rest:path("/dba/files")
+  %rest:query-param("sort", "{$sort}", "")
+  %rest:query-param("error", "{$error}")
+  %rest:query-param("info",  "{$info}")
+  %output:method("html")
+function _:files(
+  $sort   as xs:string,
+  $error  as xs:string?,
+  $info   as xs:string?
+) as element() {
+  cons:check(),
+
+  (: request data in a single step :)
+  let $files := file:children($cons:DBA-DIR)[file:is-file(.)]
+
+  return tmpl:wrap(map { 'top': $_:CAT, 'info': $info, 'error': $error },
+    <tr>
+      <td>
+        <form action="{ $_:CAT }" method="post" class="update">
+        <h2>Files</h2>
+        {
+          let $entries :=
+            for $file in $files
+            let $date := file:last-modified($file)
+            return <e name='{ file:name($file) }' date='{ $date }' size='{ file:size($file) }'/>
+          let $headers := (
+            <name>{ html:label($entries, ('File', 'Files')) }</name>,
+            <date type='dateTime' order='desc'>Date</date>,
+            <size type='bytes' order='desc'>Size</size>
+          )
+          let $buttons := html:button('delete-files', 'Delete', true())
+          let $link := function($value) { 'file/' || $value }
+          return html:table($entries, $headers, $buttons, map {}, $sort, $link)
+        }
+        </form>
+        <h3>Upload Files</h3>
+        <form action="upload-files" method="post" enctype="multipart/form-data">
+          <input type="file" name="files" multiple="multiple"/>
+          <input type="submit" value='Send'/>
+        </form>
+        <div class='note'>
+          The files are located on the DBA system in the temporary directory
+          <code>{ $cons:DBA-DIR }</code>.
+        </div>
+        <div>&#xa0;</div>
+      </td>
+    </tr>
+  )
+};
+
+(:~
+ : Redirects to the specified action.
+ : @param  $action  action to perform
+ : @param  $names   names of files
+ :)
+declare
+  %rest:POST
+  %rest:path("/dba/files")
+  %rest:query-param("action", "{$action}")
+  %rest:query-param("name",   "{$names}")
+  %output:method("html")
+function _:action(
+  $action  as xs:string,
+  $names   as xs:string*
+) {
+  web:redirect($action, map { 'name': $names, 'redirect': $_:CAT })
+};
+
+(:~
+ : Downloads a file.
+ : @param  $name  name of file
+ : @return file
+ :)
+declare
+  %rest:GET
+  %rest:path("/dba/file/{$name}")
+function _:files(
+  $name  as xs:string
+) as item()+ {
+  web:response-header(),
+  file:read-binary($cons:DBA-DIR || $name)
+};
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/files/js.js basex-8.2.3/basex-api/src/main/webapp/dba/files/js.js
--- basex-8.1.1/basex-api/src/main/webapp/dba/files/js.js	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/files/js.js	1970-01-01 00:00:00.000000000 +0000
@@ -1,130 +0,0 @@
-function buttons() {
-  var forms = document.getElementsByTagName("form");
-  for(var f = 0; f < forms.length; f++) {
-    var form = forms[f];
-    if(form.className != 'update') continue;
-
-    var inputs = form.getElementsByTagName("input");
-    var c = 0;
-    for(var i = 0; i < inputs.length; i++) {
-      if(inputs[i].type == "checkbox" && inputs[i].checked) c++;
-    }
-    var buttons = form.getElementsByTagName("button");
-    for(var i = 0; i < buttons.length; i++) {
-      var button = buttons[i], n = button.className, s = button.value, e = !button.disabled;
-      if(n == 'global') continue;
-
-      if(s == "optimize" || s == "optimize-all" || s == "drop-backup" ||
-         s == "drop-db" || s == "drop-pattern" || s == "drop-user" ||
-         s == "kill-session" || s == "restore" || s == "backup" || s == "delete" ||
-         s == "delete-logs" || s == "kill") {
-        e = c > 0;
-      }
-      button.disabled = !e;
-    }
-  }
-};
-
-function setInfo(message) {
-  setText(message, 'info');
-};
-
-function setWarning(message) {
-  setText(message, 'warning');
-};
-
-function setError(message) {
-  setText(message.replace(/Stack Trace:.*/, ''), 'error');
-};
-
-function setText(message, type) {
-  var i = document.getElementById("info");
-  i.className = type;
-  i.textContent = message;
-};
-
-var searchDelay = 200;
-var _d;
-function query(wait, success, key, query, enforce, target) {
-  var d = new Date();
-  _d = d;
-  setTimeout(function() {
-    if(_d != d) return;
-
-    var name = document.getElementById("name");
-    var resource = document.getElementById("resource");
-    var sort = document.getElementById("sort");
-    var loglist = document.getElementById("loglist");
-  
-    if(wait) setWarning(wait);
-    var req = window.XMLHttpRequest ? new XMLHttpRequest() : new ActiveXObject("Microsoft.XMLHTTP");
-    req.onreadystatechange = function() {
-      if(_d != d) return;
-      if(req.readyState == 4) {
-        if(req.status == 200) {
-          target(req.responseText);
-          if(success) setInfo(success);
-        } else {
-          setError(req.statusText.replace(/^.*?\] /, ''));
-        }
-      }
-    };
-    // synchronous querying: wait for server feedback
-    req.open("POST", key +
-      "?name=" + encodeURIComponent(name ? name.value : "") +
-      "&resource=" + encodeURIComponent(resource ? resource.value : "") +
-      "&sort=" + encodeURIComponent(sort ? sort.value : "") +
-      "&loglist=" + encodeURIComponent(loglist ? loglist.value : "") +
-      "&query=" + encodeURIComponent(query), true);
-    req.send(null);
-  }, enforce ? 0 : searchDelay);
-};
-
-var _list;
-function logslist(wait, success) {
-  var input = document.getElementById('loglist').value.trim();
-  if(_list == input) return false;
-  _list = input;
-  query(wait, success, 'loglist', input, false, function(text) {
-    document.getElementById("list").innerHTML = text;
-  })
-};
-
-var _logs;
-function logentries(wait, success) {
-  var input = document.getElementById('logs').value.trim();
-  if(_logs == input) return false;
-  _logs = input;
-  query(wait, success, 'log', input, false, function(text) {
-    document.getElementById("output").innerHTML = text;
-  });
-};
-
-var _input;
-function queryResource(wait, success) {
-  var input = document.getElementById('input').value.trim();
-  if(_input == input) return false;
-  _input = input;
-  var target = 'query-resource';
-  var enforce = false;
-  query(wait, success, target, input, enforce, function(text) {
-    document.getElementById("output").value = text;
-  });
-};
-
-var _editor;
-function xquery(wait, success, enforce) {
-  var mode = document.getElementById("mode").selectedIndex;
-  var update = mode == 2;
-  var realtime = mode == 1;
-  document.getElementById("run").disabled = realtime;
-
-  var editor = document.getElementById('editor').value;
-  if(enforce || (realtime && _editor != editor)) {
-    _editor = editor;
-    var target = update ? 'update-query' : 'eval-query';
-    query(wait, success, target, editor, enforce, function(text) {
-      document.getElementById("output").value = text;
-    });
-  }
-};
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/files/style.css basex-8.2.3/basex-api/src/main/webapp/dba/files/style.css
--- basex-8.1.1/basex-api/src/main/webapp/dba/files/style.css	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/files/style.css	1970-01-01 00:00:00.000000000 +0000
@@ -1,142 +0,0 @@
-body {
-  font-family: Calibri, "Trebuchet MS", sans-serif;
-  overflow-y: scroll;
-  margin: 1em;
-  font-size: 16px;
-}
-
-ul, dd {
-  padding-left: 1.2em;
-  margin-left: 0;
-}
-
-dl {
-  margin: 0;
-}
-
-dt {
-  margin: 0.6em 0 0.6em 0;
-  font-weight: bold;
-}
-
-table {
-  font-size: 100%;
-  padding: 0;
-  border: 0;
-  table-layout: fixed;
-}
-
-th {
-  padding: 0 1.2em .2em 0;
-}
-
-td {
-  padding: 0 1.2em 0 0;
-  vertical-align: top;
-  border: 0;
-}
-
-textarea {
-  font-family: "Consolas", "Ubuntu Mono", monospace;
-  font-size: 90%;
-  margin: 4px 0px 4px 0px;
-  width: 100%;
-}
-
-select {
-  width: 166;
-}
-
-code {
-  font-family: "Consolas", "Ubuntu Mono", monospace;
-  border: 1px solid #E3E3FF;
-  border-radius: 3px;
-  padding: 0 4px 0 4px;
-  margin: 0 2px 0 2px;
-  font-size: 90%;
-}
-
-pre {
-  font-family: "Consolas", "Ubuntu Mono", monospace;
-  font-size: 90%;
-}
-
-h1 {
-  font-size: 220%;
-  font-weight: bold;
-  color: #AA1818;
-  margin: -2px 0 0 0;
-}
-
-h2 {
-  font-size: 150%;
-  color: #CC3333;
-  margin: 0 0 0.2em 0;
-}
-
-h3 {
-  font-size: 120%;
-  color: #CC3333;
-  margin: 0.2em 0 0.2em 0;
-}
-
-h4 {
-  font-size: 100%;
-  margin: 0 0 0.4em 0;
-}
-
-hr {
-  height: 1px;
-  border: 0px;
-  background-color: #777;
-}
-
-a {
-  color: #CC3333;
-  text-decoration: none;
-}
-
-a:hover {
-  text-decoration:underline;
-}
-
-p {
-  margin: 0 0 0.6em 0;
-}
-
-.right {
-  float: right;
-}
-
-.error {
-  color: #FF3333;
-  font-weight: bold;
-}
-
-.info {
-  color: #009900;
-  font-weight: bold;
-}
-
-.warning {
-  color: #999999;
-  font-weight: bold;
-}
-
-.note {
-  color: #666666;
-}
-
-.small {
-  height: 10px;
-}
-
-.variable {
-  font-family: "Calibri", "Trebuchet MS", sans-serif;
-}
-
-.vertical {
-  width: 1px;
-  border-left: 1px solid #000000;
-  height: 100%;
-}
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/files/upload-files.xqm basex-8.2.3/basex-api/src/main/webapp/dba/files/upload-files.xqm
--- basex-8.1.1/basex-api/src/main/webapp/dba/files/upload-files.xqm	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/files/upload-files.xqm	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,31 @@
+(:~
+ : Upload files.
+ :
+ : @author Christian Grün, BaseX GmbH, 2014-15
+ :)
+module namespace _ = 'dba/files';
+
+import module namespace cons = 'dba/cons' at '../modules/cons.xqm';
+
+(:~ Top category :)
+declare variable $_:CAT := 'files';
+
+(:~
+ : Deletes files.
+ : @param  $files  map with uploaded files
+ :)
+declare
+  %rest:POST
+  %rest:path("/dba/upload-files")
+  %rest:form-param("files", "{$files}")
+  %output:method("html")
+function _:drop(
+  $files  as map(*)
+) {
+  cons:check(),
+  
+  map:for-each($files, function($name, $content) {
+    file:write-binary($cons:DBA-DIR || file:name($name), $content)
+  }),
+  web:redirect($_:CAT, map { 'info': 'Uploaded files: ' || map:size($files) })
+};
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/login.xqm basex-8.2.3/basex-api/src/main/webapp/dba/login.xqm
--- basex-8.1.1/basex-api/src/main/webapp/dba/login.xqm	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/login.xqm	2015-07-14 10:54:40.000000000 +0000
@@ -18,7 +18,7 @@
  : @return page
  :)
 declare
-  %rest:path("dba/login")
+  %rest:path("/dba/login")
   %rest:query-param("name" , "{$name}")
   %rest:query-param("url",   "{$url}")
   %rest:query-param("error", "{$error}")
@@ -42,13 +42,13 @@
               <td>
                 <input size="30" name="name" value="{ $name }" id="user"/>
                 { html:focus('user') }
-                { html:button('login', 'Login') }
               </td>
             </tr>
             <tr>
               <td><b>Password:</b></td>
               <td>
                 <input size="30" type="password" name="pass"/>
+                { html:button('login', 'Login') }
               </td>
             </tr>
             <tr>
@@ -82,7 +82,7 @@
  : @return redirect
  :)
 declare
-  %rest:path("dba/login-check")
+  %rest:path("/dba/login-check")
   %rest:query-param("name", "{$name}")
   %rest:query-param("pass", "{$pass}")
   %rest:query-param("url",  "{$url}")
@@ -135,7 +135,7 @@
  : Ends a session and redirects to the login page.
  : @return redirect
  :)
-declare %rest:path("dba/logout") function _:logout(
+declare %rest:path("/dba/logout") function _:logout(
 ) as element(rest:response) {
   let $name := $cons:SESSION/name
   let $url := string-join($cons:SESSION/(host, port), ':')
@@ -143,7 +143,7 @@
     admin:write-log('User was logged out: ' || $name),
     Session:delete($cons:SESSION-KEY),
     Session:close(),
-    web:redirect('login', map { 'nane': $name, 'url': $url })
+    web:redirect("/dba/login", map { 'nane': $name, 'url': $url })
   )
 };
 
@@ -167,7 +167,7 @@
     }
   ),
   admin:write-log('User was logged in: ' || $name),
-  web:redirect('databases')
+  web:redirect("databases")
 };
 
 (:~
@@ -183,5 +183,5 @@
   $message  as xs:string
 ) as element(rest:response) {
   admin:write-log('Login was denied: ' || $name),
-  web:redirect('login', map { 'name': $name, 'url': $url, 'error': $message })
+  web:redirect("login", map { 'name': $name, 'url': $url, 'error': $message })
 };
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/logs/delete-logs.xqm basex-8.2.3/basex-api/src/main/webapp/dba/logs/delete-logs.xqm
--- basex-8.1.1/basex-api/src/main/webapp/dba/logs/delete-logs.xqm	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/logs/delete-logs.xqm	2015-07-14 10:54:40.000000000 +0000
@@ -17,7 +17,7 @@
  :)
 declare
   %rest:GET
-  %rest:path("dba/delete-logs")
+  %rest:path("/dba/delete-logs")
   %rest:query-param("name", "{$names}")
   %output:method("html")
 function _:drop(
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/logs/logs.xqm basex-8.2.3/basex-api/src/main/webapp/dba/logs/logs.xqm
--- basex-8.1.1/basex-api/src/main/webapp/dba/logs/logs.xqm	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/logs/logs.xqm	2015-07-14 10:54:40.000000000 +0000
@@ -25,7 +25,7 @@
  :)
 declare
   %rest:GET
-  %rest:path("dba/logs")
+  %rest:path("/dba/logs")
   %rest:query-param("sort",    "{$sort}", "")
   %rest:query-param("name",    "{$name}")
   %rest:query-param("loglist", "{$loglist}")
@@ -87,7 +87,7 @@
  :)
 declare
   %rest:POST
-  %rest:path("dba/log")
+  %rest:path("/dba/log")
   %rest:query-param("name",    "{$name}")
   %rest:query-param("sort",    "{$sort}")
   %rest:query-param("loglist", "{$loglist}")
@@ -130,7 +130,7 @@
  :)
 declare
   %rest:POST
-  %rest:path("dba/loglist")
+  %rest:path("/dba/loglist")
   %rest:query-param("sort",  "{$sort}")
   %rest:query-param("query", "{$query}")
   %output:method("html")
@@ -172,7 +172,7 @@
  :)
 declare
   %rest:POST
-  %rest:path("dba/logs")
+  %rest:path("/dba/logs")
   %rest:query-param("action", "{$action}")
   %rest:query-param("name",   "{$names}")
   %output:method("html")
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/modules/cons.xqm basex-8.2.3/basex-api/src/main/webapp/dba/modules/cons.xqm
--- basex-8.1.1/basex-api/src/main/webapp/dba/modules/cons.xqm	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/modules/cons.xqm	2015-07-14 10:54:40.000000000 +0000
@@ -15,48 +15,48 @@
 (:~ Current session. :)
 declare variable $cons:SESSION := Session:get($cons:SESSION-KEY);
 
+(:~ Directory for DBA files. :)
+declare variable $cons:DBA-DIR := file:resolve-path(file:temp-dir() || 'dba/') !
+  (file:create-dir(.), .);
 (:~ Configuration file. :)
-declare variable $cons:CONFIG-XML := file:base-dir() || '../files/config.xml';
-(:~ Configuration. :)
-declare %private variable $cons:CONFIG := map:merge(
-  doc($cons:CONFIG-XML)/config/* ! map { name(): string() }
-);
+declare variable $cons:DBA-SETTINGS-FILE := $cons:DBA-DIR || 'dba-settings.xml';
 
-(:~ Language. :)
-declare variable $cons:LANGUAGE := cons:string('language');
+(:~ Permissions. :)
+declare variable $cons:PERMISSIONS := ('none', 'read', 'write', 'create', 'admin');
 
-(:~ Maximum length of XML characters (currently: 1mb). :)
-declare variable $cons:MAX-CHARS := cons:integer('maxchars');
-(:~ Maximum number of table entries (currently: 1000 rows). :)
-declare variable $cons:MAX-ROWS := cons:integer('maxrows');
+(:~ Maximum length of XML characters. :)
+declare variable $cons:K-MAX-CHARS := 'maxchars';
+(:~ Maximum number of table entries. :)
+declare variable $cons:K-MAX-ROWS := 'maxrows';
 (:~ Query timeout. :)
-declare variable $cons:TIMEOUT := cons:integer('timeout');
+declare variable $cons:K-TIMEOUT := 'timeout';
 (:~ Maximal memory consumption. :)
-declare variable $cons:MEMORY := cons:integer('memory');
+declare variable $cons:K-MEMORY := 'memory';
 (:~ Permission when running queries. :)
-declare variable $cons:PERMISSION := cons:string('permission');
-
-(:~ Permissions. :)
-declare variable $cons:PERMISSIONS := ('none', 'read', 'write', 'create', 'admin');
-
-(:~
- : Returns a configuration string for the specified key.
- : @param  $key  key
- : @return text
- :)
-declare %private function cons:string($key as xs:string) as xs:string {
-  let $text := $cons:CONFIG($key)
-  return if($text) then $text else error((), 'Missing in config.xml: "' || $text || '"')
-};
+declare variable $cons:K-PERMISSION := 'permission';
 
-(:~
- : Returns a configuration number for the specified key.
- : @param  $key  key
- : @return text
- :)
-declare %private function cons:integer($key as xs:string) as xs:integer {
-  xs:integer(cons:string($key))
-};
+(:~ Configuration. :)
+declare variable $cons:OPTION :=
+  let $defaults := map {
+    'maxchars': 100000,
+    'maxrows': 500,
+    'timeout': 5,
+    'memory': 100,
+    'permission': 'admin'
+  }
+  return try {
+    (: merge defaults with options in settings file :)
+    map:merge((
+      $defaults,
+      for $opt in doc($cons:DBA-SETTINGS-FILE)/config/*
+      let $key := $opt/name()
+      let $val := if($defaults($key) instance of xs:integer) then xs:integer($opt) else string($opt)
+      return map { $key: $val }
+    ))
+  } catch * {
+    (: settings file does not exist or is not well-formed... use defaults :)
+    $defaults
+  };
 
 (:~
  : Checks if the current client is logged in. If not, raises an error.
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/modules/html.xqm basex-8.2.3/basex-api/src/main/webapp/dba/modules/html.xqm
--- basex-8.1.1/basex-api/src/main/webapp/dba/modules/html.xqm	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/modules/html.xqm	2015-07-14 10:54:40.000000000 +0000
@@ -5,11 +5,10 @@
  :)
 module namespace html = 'dba/html';
 
-import module namespace Request = 'http://exquery.org/ns/request';
 import module namespace cons = 'dba/cons' at '../modules/cons.xqm';
 
 (: Number formats. :)
-declare variable $html:NUMBER := ('decimal','number', 'bytes');
+declare variable $html:NUMBER := ('decimal', 'number', 'bytes');
 
 (:~
  : Creates a checkbox.
@@ -213,7 +212,7 @@
           if(empty($sort) or $name = $sort) then (
             $value
           ) else (
-            html:link($value, Request:path(), map:merge(($param, map { 'sort': $name })))
+            html:link($value, "", map:merge(($param, map { 'sort': $name })))
           )
         }
       }
@@ -249,8 +248,9 @@
                  return $entry
         )
 
+        let $max := $cons:OPTION($cons:K-MAX-ROWS)
         for $entry at $c in $entries
-        return if($c <= $cons:MAX-ROWS) then (
+        return if($c <= $max) then (
           <tr>{
             for $header at $pos in $headers
             let $name := $header/name()
@@ -281,7 +281,7 @@
               )
             }
           }</tr>
-        ) else if($c = $cons:MAX-ROWS + 1) then (
+        ) else if($c = $max + 1) then (
           <tr>
             <td>{
               if($buttons) then <input type="checkbox" disabled=""/> else ()
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/modules/tmpl.xqm basex-8.2.3/basex-api/src/main/webapp/dba/modules/tmpl.xqm
--- basex-8.1.1/basex-api/src/main/webapp/dba/modules/tmpl.xqm	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/modules/tmpl.xqm	2015-07-14 10:54:40.000000000 +0000
@@ -40,11 +40,13 @@
       <title>Database Administration</title>
       <meta name="description" content="Database Administration"/>
       <meta name="author" content="BaseX Team, 2014-15"/>
-      <link rel="stylesheet" type="text/css" href="files/style.css"/> 
-      <script type="text/javascript" src="files/js.js"/>
+      <link rel="stylesheet" type="text/css" href="static/style.css"/> 
+      { $options('css') ! <link rel="stylesheet" type="text/css" href="static/{.}"/> }
+      <script type="text/javascript" src="static/js.js"/>
+      { $options('scripts') ! <script type="text/javascript" src="static/{.}"/> }
     </head>
     <body>
-      <div class="right"><img style='padding-left:10px;padding-bottom:10px;' src="files/basex.svg"/></div>
+      <div class="right"><img style='padding-left:10px;padding-bottom:10px;' src="static/basex.svg"/></div>
       <h1>Database Administration</h1>
       <div>{
         let $emph := <span>{(element b {
@@ -57,7 +59,7 @@
           cons:check(),
           let $cats := 
             let $top := $options('top')
-            for $cat in ('Databases', 'Queries', 'Logs', 'Users', 'Settings', 'Logout')
+            for $cat in ('Databases', 'Queries', 'Logs', 'Users', 'Files', 'Settings', 'Logout')
             let $link := <a href="{ lower-case($cat) }">{ $cat }</a>
             return if($top = $link) then (
               <b>{ $link }</b>
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/modules/util.xqm basex-8.2.3/basex-api/src/main/webapp/dba/modules/util.xqm
--- basex-8.1.1/basex-api/src/main/webapp/dba/modules/util.xqm	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/modules/util.xqm	2015-07-14 10:54:40.000000000 +0000
@@ -31,7 +31,7 @@
   $map    as xs:string,
   $vars   as map(*)
 ) as xs:string {
-  let $limit := $cons:MAX-CHARS
+  let $limit := $cons:OPTION($cons:K-MAX-CHARS)
   let $query := if($query) then $query else '()'
   let $q := "xquery:eval($query, map {" || $map || "}, " || util:query-options() || ")"
   let $s := "serialize(" || $q || ", map{ 'limit': $limit*2, 'method': 'adaptive' })"
@@ -59,9 +59,9 @@
  : @return options
  :)
 declare %private function util:query-options() {
-  "map { 'timeout':" || $cons:TIMEOUT ||
-       ",'memory':" || $cons:MEMORY ||
-       ",'permission':'" || $cons:PERMISSION || "' }"
+  "map { 'timeout':" || $cons:OPTION($cons:K-TIMEOUT) ||
+       ",'memory':" || $cons:OPTION($cons:K-MEMORY) ||
+       ",'permission':'" || $cons:OPTION($cons:K-PERMISSION) || "' }"
 };
 
 (:~
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/queries/queries.xqm basex-8.2.3/basex-api/src/main/webapp/dba/queries/queries.xqm
--- basex-8.1.1/basex-api/src/main/webapp/dba/queries/queries.xqm	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/queries/queries.xqm	2015-07-14 10:54:40.000000000 +0000
@@ -10,50 +10,72 @@
 import module namespace tmpl = 'dba/tmpl' at '../modules/tmpl.xqm';
 import module namespace util = 'dba/util' at '../modules/util.xqm';
 
-(:~ Top category :)
+(:~ Top category. :)
 declare variable $_:CAT := 'queries';
+(:~ Query file suffix. :)
+declare variable $_:SUFFIX := '.xq';
 
 (:~
  : Queries page.
- : @param  $query  input query
- : @param  $error  error string
- : @param  $info   info string
+ : @param  $error   error string
+ : @param  $info    info string
  : @return HTML page
  :)
 declare
   %rest:GET
-  %rest:path("dba/queries")
-  %rest:query-param("query",  "{$query}")
+  %rest:path("/dba/queries")
   %rest:query-param("error",  "{$error}")
   %rest:query-param("info",   "{$info}")
   %output:method("html")
 function _:queries(
-  $query  as xs:string?,
-  $error  as xs:string?,
-  $info   as xs:string?
+  $error   as xs:string?,
+  $info    as xs:string?
 ) as element() {
   cons:check(),
 
-  let $f := function($b) { "xquery('Please wait…', 'Query was successful.', " || $b || ");" }
-  return tmpl:wrap(map { 'top': $_:CAT, 'info': $info, 'error': $error },
+  let $f := function($b) { "editor('Please wait…', 'Query was successful.', " || $b || ");" }
+  return tmpl:wrap(
+    map {
+      'top': $_:CAT, 'info': $info, 'error': $error,
+      'css': 'codemirror/lib/codemirror.css',
+      'scripts': ('editor.js', 'codemirror/lib/codemirror.js',
+                  'codemirror/mode/xquery/xquery.js','codemirror/mode/xml/xml.js')
+    },
     <tr>
       <td width='50%'>
         <table width='100%'>
           <tr>
-            <td>
-              <button id='run' onClick="{ $f(true()) }">Run</button>
-              <select id='mode' onChange='{ $f(false()) }'>{
+            <td width='80%'>
+              <select id='mode' onchange='{ $f(false()) }'>{
                 ('Standard', 'Realtime', 'Updating') ! element option { . }
               }</select>
+              <button id='run' onclick="{ $f(true()) }">Run</button>
             </td>
-            <td align='right'>
+            <td width='20%' align='right'>
               <h2>Editor</h2>
             </td>
           </tr>
         </table>
-        <textarea id='editor' rows='20' spellcheck='false' onkeyup="{ $f(false()) }">{
-          $query
-        }</textarea>
+        <textarea id='editor' name='editor' rows='20' spellcheck='false' onkeyup="{ $f(false()) }"/>
+        <table width='100%'>
+          <tr>
+            <td>
+              <div align='right'>
+                <form autocomplete='off' action='javascript:void(0);'>
+                  <input id='file' name='file' placeholder='Name of query'
+                         list='files' oninput='checkButtons()' onpropertychange='checkButtons()'/>
+                  <datalist id='files'>{ _:files() ! element option { . } }</datalist>
+                  <button type='submit' name='open' id='open' disabled='true'
+                          onclick='openQuery()'>Open</button>
+                  <button type='save' name='save' id='save' disabled='true'
+                          onclick='saveQuery()'>Save</button>
+                  <button type='delete' name='delete' id='delete' disabled='true'
+                          onclick='deleteQuery()'>Delete</button>
+                </form>
+              </div>
+            </td>
+          </tr>
+        </table>
         { html:focus('editor') }
       </td>
       <td width='50%'>
@@ -65,6 +87,7 @@
           </tr>
         </table>
         <textarea id='output' rows='20' readonly='' spellcheck='false'/>
+        <script type="text/javascript">loadCodeMirror();</script>
       </td>
     </tr>
   )
@@ -76,8 +99,8 @@
  : @return result of query
  :)
 declare
-  %rest:path("dba/eval-query")
-  %rest:query-param("query", "{$query}")
+  %rest:POST("{$query}")
+  %rest:path("/dba/eval-query")
   %output:method("text")
 function _:eval-query(
   $query  as xs:string?
@@ -87,12 +110,65 @@
 };
 
 (:~
+ : Returns the contents of a query file.
+ : @param  $name  name of query file (without suffix)
+ : @return query string
+ :)
+declare
+  %rest:path("/dba/open-query")
+  %rest:query-param("name", "{$name}")
+  %output:method("text")
+function _:open-query(
+  $name  as xs:string
+) as xs:string {
+  cons:check(),
+  file:read-text(_:to-path($name))
+};
+
+(:~
+ : Delete a query file and returns the names of stored queries.
+ : @param  $name  name of query file (without suffix)
+ : @return names of stored queries
+ :)
+declare
+  %rest:path("/dba/delete-query")
+  %rest:query-param("name", "{$name}")
+  %output:method("text")
+function _:delete-query(
+  $name  as xs:string
+) as xs:string {
+  cons:check(),
+  file:delete(_:to-path($name)),
+  string-join(_:files(), '/')
+};
+
+(:~
+ : Saves a query file and returns the list of stored queries.
+ : @param  $name   name of query file (without suffix)
+ : @param  $query  query string
+ : @return names of stored queries
+ :)
+declare
+  %rest:POST("{$query}")
+  %rest:path("/dba/save-query")
+  %rest:query-param("name", "{$name}")
+  %output:method("text")
+function _:save-query(
+  $name   as xs:string,
+  $query  as xs:string
+) as xs:string {
+  cons:check(),
+  file:write-text(_:to-path($name), $query),
+  string-join(_:files(), '/')
+};
+
+(:~
  : Runs an updating query.
  : @param  $query  query
  :)
 declare
   %updating
-  %rest:path("dba/update-query")
+  %rest:path("/dba/update-query")
   %rest:query-param("query", "{$query}")
   %output:method("text")
 function _:update-query(
@@ -106,8 +182,28 @@
  : Returns the options for evaluating a query.
  : @return options
  :)
-declare %private function _:query-options() {
-  "map { 'timeout':" || $cons:TIMEOUT ||
-       ",'memory':" || $cons:MEMORY ||
-       ",'permission':'" || $cons:PERMISSION || "' }"
+declare %private function _:query-options() as xs:string {
+  "map { 'timeout':" || $cons:OPTION($cons:K-TIMEOUT) ||
+       ",'memory':" || $cons:OPTION($cons:K-MEMORY) ||
+       ",'permission':'" || $cons:OPTION($cons:K-PERMISSION) || "' }"
+};
+
+(:~
+ : Returns a normalized file path for the specified file name.
+ : @param  $name  file name
+ : @return file path
+ :)
+declare %private function _:to-path(
+  $name  as xs:string
+) as xs:string {
+  $cons:DBA-DIR || translate($name, '\/:*?"<>|', '---------') || $_:SUFFIX
+};
+
+(:~
+ : Returns the names of all files.
+ : @return list of files
+ :)
+declare %private function _:files() as xs:string* {
+  for $file in file:list($cons:DBA-DIR, false(), '*' || $_:SUFFIX)
+  return replace($file, $_:SUFFIX || '$', '')
 };
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/settings/settings.xqm basex-8.2.3/basex-api/src/main/webapp/dba/settings/settings.xqm
--- basex-8.1.1/basex-api/src/main/webapp/dba/settings/settings.xqm	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/settings/settings.xqm	2015-07-14 10:54:40.000000000 +0000
@@ -9,7 +9,7 @@
 import module namespace cons = 'dba/cons' at '../modules/cons.xqm';
 import module namespace tmpl = 'dba/tmpl' at '../modules/tmpl.xqm';
 
-declare option query:write-lock "settings";
+declare option query:write-lock 'settings';
 
 (:~ Top category :)
 declare variable $_:CAT := 'settings';
@@ -19,7 +19,7 @@
  :)
 declare
   %rest:GET
-  %rest:path("dba/settings")
+  %rest:path("/dba/settings")
   %output:method("html")
 function _:settings(
 ) as element() {
@@ -34,48 +34,30 @@
             <tr>
               <td colspan='2'><h3>Querying</h3></td>
             </tr>
-            <tr>
-              <td><b>TIMEOUT:</b></td>
-              <td><input name="timeout" type="number" value="{ $cons:TIMEOUT }"/>
-                <span class='note'> &#xa0;
-                  …query timeout (seconds)
-                </span>
-              </td>
-            </tr>
-            <tr>
-              <td><b>MEMORY:</b></td>
-              <td><input name="memory" type="number" value="{ $cons:MEMORY }"/>
-                <span class='note'> &#xa0;
-                  …memory limit (mb) during query execution
-                </span>
-              </td>
-            </tr>
-            <tr>
-              <td><b>MAXCHARS:</b></td>
-              <td><input name="maxchars" type="number" value="{ $cons:MAX-CHARS }"/>
-                <span class='note'> &#xa0;
-                  …maximum number of characters in query results
-                </span>
-              </td>
-            </tr>
-            <tr>
-              <td><b>MAXROWS:</b></td>
-              <td><input name="maxrows" type="number" value="{ $cons:MAX-ROWS }"/>
-                <span class='note'> &#xa0;
-                  …maximum number of displayed table rows
-                </span>
-              </td>
-            </tr>
+            {
+              for $option in element options {
+                element { $cons:K-TIMEOUT } { '…query timeout (seconds)' },
+                element { $cons:K-MEMORY } { '…memory limit (mb) during query execution' },
+                element { $cons:K-MAX-CHARS } { '…maximum number of characters in query results' },
+                element { $cons:K-MAX-ROWS } { '…maximum number of displayed table rows' }
+              }/*
+              let $key := name($option)
+              return <tr>
+                <td><b>{ upper-case($key) }:</b></td>
+                <td><input name="{ $key }" type="number" value="{ $cons:OPTION($key) }"/>
+                  <span class='note'> &#xa0; { $option/text() }</span>
+                </td>
+              </tr>
+            }
             <tr>
               <td><b>PERMISSION:</b></td>
               <td>
                 <select name="permission">{
+                  let $pm := $cons:OPTION($cons:K-PERMISSION)
                   for $p in $cons:PERMISSIONS
-                  return element option { attribute selected { }[$p = $cons:PERMISSION], $p }
+                  return element option { attribute selected { }[$p = $pm], $p }
                 }</select>
-                <span class='note'> &#xa0;
-                  …for running queries
-                </span>
+                <span class='note'> &#xa0; …for running queries</span>
               </td>
             </tr>
           </table>
@@ -90,20 +72,18 @@
  :)
 declare
   %rest:POST
-  %rest:path("dba/settings")
+  %rest:path("/dba/settings")
   %output:method("html")
 function _:settings-save(
 ) {
   cons:check(),
 
-  let $config := doc($cons:CONFIG-XML)/config update (
+  let $config := element config {
     for $key in Request:parameter-names()
-    (: skip empty values :)
-    for $value in Request:parameter($key)[.]
-    return replace value of node *[name() = $key] with $value
-  )
+    return element { $key } { Request:parameter($key) }
+  }
   return (
-    file:write($cons:CONFIG-XML, $config),
+    file:write($cons:DBA-SETTINGS-FILE, $config),
     web:redirect("settings")
   )
 };
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/static/basex.svg basex-8.2.3/basex-api/src/main/webapp/dba/static/basex.svg
--- basex-8.1.1/basex-api/src/main/webapp/dba/static/basex.svg	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/static/basex.svg	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,78 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<svg
+   xmlns:dc="http://purl.org/dc/elements/1.1/"
+   xmlns:cc="http://creativecommons.org/ns#"
+   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
+   xmlns:svg="http://www.w3.org/2000/svg"
+   xmlns="http://www.w3.org/2000/svg"
+   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
+   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
+   viewBox="0 0 82.088621 73.135418"
+   height="73.135414"
+   width="82.088623"
+   xml:space="preserve"
+   version="1.1"
+   id="svg2"
+   inkscape:version="0.48.5 r10040"
+   sodipodi:docname="basex.svg"><sodipodi:namedview
+     pagecolor="#ffffff"
+     bordercolor="#666666"
+     borderopacity="1"
+     objecttolerance="10"
+     gridtolerance="10"
+     guidetolerance="10"
+     inkscape:pageopacity="0"
+     inkscape:pageshadow="2"
+     inkscape:window-width="2498"
+     inkscape:window-height="1417"
+     id="namedview3026"
+     showgrid="false"
+     fit-margin-top="1"
+     fit-margin-left="1"
+     fit-margin-right="1"
+     fit-margin-bottom="1"
+     inkscape:zoom="7.59107"
+     inkscape:cx="92.212069"
+     inkscape:cy="-8.8800238"
+     inkscape:window-x="-8"
+     inkscape:window-y="-8"
+     inkscape:window-maximized="1"
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+         rdf:about=""><dc:format>image/svg+xml</dc:format><dc:type
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diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/static/codemirror/lib/codemirror.css basex-8.2.3/basex-api/src/main/webapp/dba/static/codemirror/lib/codemirror.css
--- basex-8.1.1/basex-api/src/main/webapp/dba/static/codemirror/lib/codemirror.css	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/static/codemirror/lib/codemirror.css	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,322 @@
+/* BASICS */
+
+.CodeMirror {
+  font-family: "Consolas", "Ubuntu Mono", monospace; 
+}
+
+/* PADDING */
+
+.CodeMirror-lines {
+  padding: 4px 0; /* Vertical padding around content */
+}
+.CodeMirror pre {
+  padding: 0 4px; /* Horizontal padding of content */
+}
+
+.CodeMirror-scrollbar-filler, .CodeMirror-gutter-filler {
+  background-color: white; /* The little square between H and V scrollbars */
+}
+
+/* GUTTER */
+
+.CodeMirror-gutters {
+  border-right: 1px solid #ddd;
+  background-color: #f7f7f7;
+  white-space: nowrap;
+}
+.CodeMirror-linenumbers {}
+.CodeMirror-linenumber {
+  padding: 0 3px 0 5px;
+  min-width: 20px;
+  text-align: right;
+  color: #999;
+  white-space: nowrap;
+}
+
+.CodeMirror-guttermarker { color: black; }
+.CodeMirror-guttermarker-subtle { color: #999; }
+
+/* CURSOR */
+
+.CodeMirror div.CodeMirror-cursor {
+  border-left: 1px solid black;
+}
+/* Shown when moving in bi-directional text */
+.CodeMirror div.CodeMirror-secondarycursor {
+  border-left: 1px solid silver;
+}
+.CodeMirror.cm-fat-cursor div.CodeMirror-cursor {
+  width: auto;
+  border: 0;
+  background: #7e7;
+}
+.CodeMirror.cm-fat-cursor div.CodeMirror-cursors {
+  z-index: 1;
+}
+
+.cm-animate-fat-cursor {
+  width: auto;
+  border: 0;
+  -webkit-animation: blink 1.06s steps(1) infinite;
+  -moz-animation: blink 1.06s steps(1) infinite;
+  animation: blink 1.06s steps(1) infinite;
+}
+@-moz-keyframes blink {
+  0% { background: #7e7; }
+  50% { background: none; }
+  100% { background: #7e7; }
+}
+@-webkit-keyframes blink {
+  0% { background: #7e7; }
+  50% { background: none; }
+  100% { background: #7e7; }
+}
+@keyframes blink {
+  0% { background: #7e7; }
+  50% { background: none; }
+  100% { background: #7e7; }
+}
+
+/* Can style cursor different in overwrite (non-insert) mode */
+div.CodeMirror-overwrite div.CodeMirror-cursor {}
+
+.cm-tab { display: inline-block; text-decoration: inherit; }
+
+.CodeMirror-ruler {
+  border-left: 1px solid #ccc;
+  position: absolute;
+}
+
+/* DEFAULT THEME */
+
+.cm-s-default .cm-keyword {color: #708;}
+.cm-s-default .cm-atom {color: #219;}
+.cm-s-default .cm-number {color: #164;}
+.cm-s-default .cm-def {color: #00f;}
+.cm-s-default .cm-variable,
+.cm-s-default .cm-punctuation,
+.cm-s-default .cm-property,
+.cm-s-default .cm-operator {}
+.cm-s-default .cm-variable-2 {color: #05a;}
+.cm-s-default .cm-variable-3 {color: #085;}
+.cm-s-default .cm-comment {color: #a50;}
+.cm-s-default .cm-string {color: #a11;}
+.cm-s-default .cm-string-2 {color: #f50;}
+.cm-s-default .cm-meta {color: #555;}
+.cm-s-default .cm-qualifier {color: #555;}
+.cm-s-default .cm-builtin {color: #30a;}
+.cm-s-default .cm-bracket {color: #997;}
+.cm-s-default .cm-tag {color: #170;}
+.cm-s-default .cm-attribute {color: #00c;}
+.cm-s-default .cm-header {color: blue;}
+.cm-s-default .cm-quote {color: #090;}
+.cm-s-default .cm-hr {color: #999;}
+.cm-s-default .cm-link {color: #00c;}
+
+.cm-negative {color: #d44;}
+.cm-positive {color: #292;}
+.cm-header, .cm-strong {font-weight: bold;}
+.cm-em {font-style: italic;}
+.cm-link {text-decoration: underline;}
+.cm-strikethrough {text-decoration: line-through;}
+
+.cm-s-default .cm-error {color: #f00;}
+.cm-invalidchar {color: #f00;}
+
+.CodeMirror-composing { border-bottom: 2px solid; }
+
+/* Default styles for common addons */
+
+div.CodeMirror span.CodeMirror-matchingbracket {color: #0f0;}
+div.CodeMirror span.CodeMirror-nonmatchingbracket {color: #f22;}
+.CodeMirror-matchingtag { background: rgba(255, 150, 0, .3); }
+.CodeMirror-activeline-background {background: #e8f2ff;}
+
+/* STOP */
+
+/* The rest of this file contains styles related to the mechanics of
+   the editor. You probably shouldn't touch them. */
+
+.CodeMirror {
+  position: relative;
+  overflow: hidden;
+  background: white;
+}
+
+.CodeMirror-scroll {
+  overflow: scroll !important; /* Things will break if this is overridden */
+  /* 30px is the magic margin used to hide the element's real scrollbars */
+  /* See overflow: hidden in .CodeMirror */
+  margin-bottom: -30px; margin-right: -30px;
+  padding-bottom: 30px;
+  height: 100%;
+  outline: none; /* Prevent dragging from highlighting the element */
+  position: relative;
+}
+.CodeMirror-sizer {
+  position: relative;
+  border-right: 30px solid transparent;
+}
+
+/* The fake, visible scrollbars. Used to force redraw during scrolling
+   before actuall scrolling happens, thus preventing shaking and
+   flickering artifacts. */
+.CodeMirror-vscrollbar, .CodeMirror-hscrollbar, .CodeMirror-scrollbar-filler, .CodeMirror-gutter-filler {
+  position: absolute;
+  z-index: 6;
+  display: none;
+}
+.CodeMirror-vscrollbar {
+  right: 0; top: 0;
+  overflow-x: hidden;
+  overflow-y: scroll;
+}
+.CodeMirror-hscrollbar {
+  bottom: 0; left: 0;
+  overflow-y: hidden;
+  overflow-x: scroll;
+}
+.CodeMirror-scrollbar-filler {
+  right: 0; bottom: 0;
+}
+.CodeMirror-gutter-filler {
+  left: 0; bottom: 0;
+}
+
+.CodeMirror-gutters {
+  position: absolute; left: 0; top: 0;
+  z-index: 3;
+}
+.CodeMirror-gutter {
+  white-space: normal;
+  height: 100%;
+  display: inline-block;
+  margin-bottom: -30px;
+  /* Hack to make IE7 behave */
+  *zoom:1;
+  *display:inline;
+}
+.CodeMirror-gutter-wrapper {
+  position: absolute;
+  z-index: 4;
+  height: 100%;
+}
+.CodeMirror-gutter-elt {
+  position: absolute;
+  cursor: default;
+  z-index: 4;
+}
+.CodeMirror-gutter-wrapper {
+  -webkit-user-select: none;
+  -moz-user-select: none;
+  user-select: none;
+}
+
+.CodeMirror-lines {
+  cursor: text;
+  min-height: 1px; /* prevents collapsing before first draw */
+}
+.CodeMirror pre {
+  /* Reset some styles that the rest of the page might have set */
+  -moz-border-radius: 0; -webkit-border-radius: 0; border-radius: 0;
+  border-width: 0;
+  background: transparent;
+  font-family: inherit;
+  font-size: inherit;
+  margin: 0;
+  white-space: pre;
+  word-wrap: normal;
+  line-height: inherit;
+  color: inherit;
+  z-index: 2;
+  position: relative;
+  overflow: visible;
+  -webkit-tap-highlight-color: transparent;
+}
+.CodeMirror-wrap pre {
+  word-wrap: break-word;
+  white-space: pre-wrap;
+  word-break: normal;
+}
+
+.CodeMirror-linebackground {
+  position: absolute;
+  left: 0; right: 0; top: 0; bottom: 0;
+  z-index: 0;
+}
+
+.CodeMirror-linewidget {
+  position: relative;
+  z-index: 2;
+  overflow: auto;
+}
+
+.CodeMirror-widget {}
+
+.CodeMirror-code {
+  outline: none;
+}
+
+/* Force content-box sizing for the elements where we expect it */
+.CodeMirror-scroll,
+.CodeMirror-sizer,
+.CodeMirror-gutter,
+.CodeMirror-gutters,
+.CodeMirror-linenumber {
+  -moz-box-sizing: content-box;
+  box-sizing: content-box;
+}
+
+.CodeMirror-measure {
+  position: absolute;
+  width: 100%;
+  height: 0;
+  overflow: hidden;
+  visibility: hidden;
+}
+.CodeMirror-measure pre { position: static; }
+
+.CodeMirror div.CodeMirror-cursor {
+  position: absolute;
+  border-right: none;
+  width: 0;
+}
+
+div.CodeMirror-cursors {
+  visibility: hidden;
+  position: relative;
+  z-index: 3;
+}
+.CodeMirror-focused div.CodeMirror-cursors {
+  visibility: visible;
+}
+
+.CodeMirror-selected { background: #d9d9d9; }
+.CodeMirror-focused .CodeMirror-selected { background: #d7d4f0; }
+.CodeMirror-crosshair { cursor: crosshair; }
+.CodeMirror ::selection { background: #d7d4f0; }
+.CodeMirror ::-moz-selection { background: #d7d4f0; }
+
+.cm-searching {
+  background: #ffa;
+  background: rgba(255, 255, 0, .4);
+}
+
+/* IE7 hack to prevent it from returning funny offsetTops on the spans */
+.CodeMirror span { *vertical-align: text-bottom; }
+
+/* Used to force a border model for a node */
+.cm-force-border { padding-right: .1px; }
+
+@media print {
+  /* Hide the cursor when printing */
+  .CodeMirror div.CodeMirror-cursors {
+    visibility: hidden;
+  }
+}
+
+/* See issue #2901 */
+.cm-tab-wrap-hack:after { content: ''; }
+
+/* Help users use markselection to safely style text background */
+span.CodeMirror-selectedtext { background: none; }
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/static/codemirror/lib/codemirror.js basex-8.2.3/basex-api/src/main/webapp/dba/static/codemirror/lib/codemirror.js
--- basex-8.1.1/basex-api/src/main/webapp/dba/static/codemirror/lib/codemirror.js	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/static/codemirror/lib/codemirror.js	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,8747 @@
+// CodeMirror, copyright (c) by Marijn Haverbeke and others
+// Distributed under an MIT license: http://codemirror.net/LICENSE
+
+// This is CodeMirror (http://codemirror.net), a code editor
+// implemented in JavaScript on top of the browser's DOM.
+//
+// You can find some technical background for some of the code below
+// at http://marijnhaverbeke.nl/blog/#cm-internals .
+
+(function(mod) {
+  if (typeof exports == "object" && typeof module == "object") // CommonJS
+    module.exports = mod();
+  else if (typeof define == "function" && define.amd) // AMD
+    return define([], mod);
+  else // Plain browser env
+    this.CodeMirror = mod();
+})(function() {
+  "use strict";
+
+  // BROWSER SNIFFING
+
+  // Kludges for bugs and behavior differences that can't be feature
+  // detected are enabled based on userAgent etc sniffing.
+
+  var gecko = /gecko\/\d/i.test(navigator.userAgent);
+  var ie_upto10 = /MSIE \d/.test(navigator.userAgent);
+  var ie_11up = /Trident\/(?:[7-9]|\d{2,})\..*rv:(\d+)/.exec(navigator.userAgent);
+  var ie = ie_upto10 || ie_11up;
+  var ie_version = ie && (ie_upto10 ? document.documentMode || 6 : ie_11up[1]);
+  var webkit = /WebKit\//.test(navigator.userAgent);
+  var qtwebkit = webkit && /Qt\/\d+\.\d+/.test(navigator.userAgent);
+  var chrome = /Chrome\//.test(navigator.userAgent);
+  var presto = /Opera\//.test(navigator.userAgent);
+  var safari = /Apple Computer/.test(navigator.vendor);
+  var mac_geMountainLion = /Mac OS X 1\d\D([8-9]|\d\d)\D/.test(navigator.userAgent);
+  var phantom = /PhantomJS/.test(navigator.userAgent);
+
+  var ios = /AppleWebKit/.test(navigator.userAgent) && /Mobile\/\w+/.test(navigator.userAgent);
+  // This is woefully incomplete. Suggestions for alternative methods welcome.
+  var mobile = ios || /Android|webOS|BlackBerry|Opera Mini|Opera Mobi|IEMobile/i.test(navigator.userAgent);
+  var mac = ios || /Mac/.test(navigator.platform);
+  var windows = /win/i.test(navigator.platform);
+
+  var presto_version = presto && navigator.userAgent.match(/Version\/(\d*\.\d*)/);
+  if (presto_version) presto_version = Number(presto_version[1]);
+  if (presto_version && presto_version >= 15) { presto = false; webkit = true; }
+  // Some browsers use the wrong event properties to signal cmd/ctrl on OS X
+  var flipCtrlCmd = mac && (qtwebkit || presto && (presto_version == null || presto_version < 12.11));
+  var captureRightClick = gecko || (ie && ie_version >= 9);
+
+  // Optimize some code when these features are not used.
+  var sawReadOnlySpans = false, sawCollapsedSpans = false;
+
+  // EDITOR CONSTRUCTOR
+
+  // A CodeMirror instance represents an editor. This is the object
+  // that user code is usually dealing with.
+
+  function CodeMirror(place, options) {
+    if (!(this instanceof CodeMirror)) return new CodeMirror(place, options);
+
+    this.options = options = options ? copyObj(options) : {};
+    // Determine effective options based on given values and defaults.
+    copyObj(defaults, options, false);
+    setGuttersForLineNumbers(options);
+
+    var doc = options.value;
+    if (typeof doc == "string") doc = new Doc(doc, options.mode);
+    this.doc = doc;
+
+    var input = new CodeMirror.inputStyles[options.inputStyle](this);
+    var display = this.display = new Display(place, doc, input);
+    display.wrapper.CodeMirror = this;
+    updateGutters(this);
+    themeChanged(this);
+    if (options.lineWrapping)
+      this.display.wrapper.className += " CodeMirror-wrap";
+    if (options.autofocus && !mobile) display.input.focus();
+    initScrollbars(this);
+
+    this.state = {
+      keyMaps: [],  // stores maps added by addKeyMap
+      overlays: [], // highlighting overlays, as added by addOverlay
+      modeGen: 0,   // bumped when mode/overlay changes, used to invalidate highlighting info
+      overwrite: false,
+      delayingBlurEvent: false,
+      focused: false,
+      suppressEdits: false, // used to disable editing during key handlers when in readOnly mode
+      pasteIncoming: false, cutIncoming: false, // help recognize paste/cut edits in input.poll
+      draggingText: false,
+      highlight: new Delayed(), // stores highlight worker timeout
+      keySeq: null,  // Unfinished key sequence
+      specialChars: null
+    };
+
+    var cm = this;
+
+    // Override magic textarea content restore that IE sometimes does
+    // on our hidden textarea on reload
+    if (ie && ie_version < 11) setTimeout(function() { cm.display.input.reset(true); }, 20);
+
+    registerEventHandlers(this);
+    ensureGlobalHandlers();
+
+    startOperation(this);
+    this.curOp.forceUpdate = true;
+    attachDoc(this, doc);
+
+    if ((options.autofocus && !mobile) || cm.hasFocus())
+      setTimeout(bind(onFocus, this), 20);
+    else
+      onBlur(this);
+
+    for (var opt in optionHandlers) if (optionHandlers.hasOwnProperty(opt))
+      optionHandlers[opt](this, options[opt], Init);
+    maybeUpdateLineNumberWidth(this);
+    if (options.finishInit) options.finishInit(this);
+    for (var i = 0; i < initHooks.length; ++i) initHooks[i](this);
+    endOperation(this);
+    // Suppress optimizelegibility in Webkit, since it breaks text
+    // measuring on line wrapping boundaries.
+    if (webkit && options.lineWrapping &&
+        getComputedStyle(display.lineDiv).textRendering == "optimizelegibility")
+      display.lineDiv.style.textRendering = "auto";
+  }
+
+  // DISPLAY CONSTRUCTOR
+
+  // The display handles the DOM integration, both for input reading
+  // and content drawing. It holds references to DOM nodes and
+  // display-related state.
+
+  function Display(place, doc, input) {
+    var d = this;
+    this.input = input;
+
+    // Covers bottom-right square when both scrollbars are present.
+    d.scrollbarFiller = elt("div", null, "CodeMirror-scrollbar-filler");
+    d.scrollbarFiller.setAttribute("cm-not-content", "true");
+    // Covers bottom of gutter when coverGutterNextToScrollbar is on
+    // and h scrollbar is present.
+    d.gutterFiller = elt("div", null, "CodeMirror-gutter-filler");
+    d.gutterFiller.setAttribute("cm-not-content", "true");
+    // Will contain the actual code, positioned to cover the viewport.
+    d.lineDiv = elt("div", null, "CodeMirror-code");
+    // Elements are added to these to represent selection and cursors.
+    d.selectionDiv = elt("div", null, null, "position: relative; z-index: 1");
+    d.cursorDiv = elt("div", null, "CodeMirror-cursors");
+    // A visibility: hidden element used to find the size of things.
+    d.measure = elt("div", null, "CodeMirror-measure");
+    // When lines outside of the viewport are measured, they are drawn in this.
+    d.lineMeasure = elt("div", null, "CodeMirror-measure");
+    // Wraps everything that needs to exist inside the vertically-padded coordinate system
+    d.lineSpace = elt("div", [d.measure, d.lineMeasure, d.selectionDiv, d.cursorDiv, d.lineDiv],
+                      null, "position: relative; outline: none");
+    // Moved around its parent to cover visible view.
+    d.mover = elt("div", [elt("div", [d.lineSpace], "CodeMirror-lines")], null, "position: relative");
+    // Set to the height of the document, allowing scrolling.
+    d.sizer = elt("div", [d.mover], "CodeMirror-sizer");
+    d.sizerWidth = null;
+    // Behavior of elts with overflow: auto and padding is
+    // inconsistent across browsers. This is used to ensure the
+    // scrollable area is big enough.
+    d.heightForcer = elt("div", null, null, "position: absolute; height: " + scrollerGap + "px; width: 1px;");
+    // Will contain the gutters, if any.
+    d.gutters = elt("div", null, "CodeMirror-gutters");
+    d.lineGutter = null;
+    // Actual scrollable element.
+    d.scroller = elt("div", [d.sizer, d.heightForcer, d.gutters], "CodeMirror-scroll");
+    d.scroller.setAttribute("tabIndex", "-1");
+    // The element in which the editor lives.
+    d.wrapper = elt("div", [d.scrollbarFiller, d.gutterFiller, d.scroller], "CodeMirror");
+
+    // Work around IE7 z-index bug (not perfect, hence IE7 not really being supported)
+    if (ie && ie_version < 8) { d.gutters.style.zIndex = -1; d.scroller.style.paddingRight = 0; }
+    if (!webkit && !(gecko && mobile)) d.scroller.draggable = true;
+
+    if (place) {
+      if (place.appendChild) place.appendChild(d.wrapper);
+      else place(d.wrapper);
+    }
+
+    // Current rendered range (may be bigger than the view window).
+    d.viewFrom = d.viewTo = doc.first;
+    d.reportedViewFrom = d.reportedViewTo = doc.first;
+    // Information about the rendered lines.
+    d.view = [];
+    d.renderedView = null;
+    // Holds info about a single rendered line when it was rendered
+    // for measurement, while not in view.
+    d.externalMeasured = null;
+    // Empty space (in pixels) above the view
+    d.viewOffset = 0;
+    d.lastWrapHeight = d.lastWrapWidth = 0;
+    d.updateLineNumbers = null;
+
+    d.nativeBarWidth = d.barHeight = d.barWidth = 0;
+    d.scrollbarsClipped = false;
+
+    // Used to only resize the line number gutter when necessary (when
+    // the amount of lines crosses a boundary that makes its width change)
+    d.lineNumWidth = d.lineNumInnerWidth = d.lineNumChars = null;
+    // Set to true when a non-horizontal-scrolling line widget is
+    // added. As an optimization, line widget aligning is skipped when
+    // this is false.
+    d.alignWidgets = false;
+
+    d.cachedCharWidth = d.cachedTextHeight = d.cachedPaddingH = null;
+
+    // Tracks the maximum line length so that the horizontal scrollbar
+    // can be kept static when scrolling.
+    d.maxLine = null;
+    d.maxLineLength = 0;
+    d.maxLineChanged = false;
+
+    // Used for measuring wheel scrolling granularity
+    d.wheelDX = d.wheelDY = d.wheelStartX = d.wheelStartY = null;
+
+    // True when shift is held down.
+    d.shift = false;
+
+    // Used to track whether anything happened since the context menu
+    // was opened.
+    d.selForContextMenu = null;
+
+    d.activeTouch = null;
+
+    input.init(d);
+  }
+
+  // STATE UPDATES
+
+  // Used to get the editor into a consistent state again when options change.
+
+  function loadMode(cm) {
+    cm.doc.mode = CodeMirror.getMode(cm.options, cm.doc.modeOption);
+    resetModeState(cm);
+  }
+
+  function resetModeState(cm) {
+    cm.doc.iter(function(line) {
+      if (line.stateAfter) line.stateAfter = null;
+      if (line.styles) line.styles = null;
+    });
+    cm.doc.frontier = cm.doc.first;
+    startWorker(cm, 100);
+    cm.state.modeGen++;
+    if (cm.curOp) regChange(cm);
+  }
+
+  function wrappingChanged(cm) {
+    if (cm.options.lineWrapping) {
+      addClass(cm.display.wrapper, "CodeMirror-wrap");
+      cm.display.sizer.style.minWidth = "";
+      cm.display.sizerWidth = null;
+    } else {
+      rmClass(cm.display.wrapper, "CodeMirror-wrap");
+      findMaxLine(cm);
+    }
+    estimateLineHeights(cm);
+    regChange(cm);
+    clearCaches(cm);
+    setTimeout(function(){updateScrollbars(cm);}, 100);
+  }
+
+  // Returns a function that estimates the height of a line, to use as
+  // first approximation until the line becomes visible (and is thus
+  // properly measurable).
+  function estimateHeight(cm) {
+    var th = textHeight(cm.display), wrapping = cm.options.lineWrapping;
+    var perLine = wrapping && Math.max(5, cm.display.scroller.clientWidth / charWidth(cm.display) - 3);
+    return function(line) {
+      if (lineIsHidden(cm.doc, line)) return 0;
+
+      var widgetsHeight = 0;
+      if (line.widgets) for (var i = 0; i < line.widgets.length; i++) {
+        if (line.widgets[i].height) widgetsHeight += line.widgets[i].height;
+      }
+
+      if (wrapping)
+        return widgetsHeight + (Math.ceil(line.text.length / perLine) || 1) * th;
+      else
+        return widgetsHeight + th;
+    };
+  }
+
+  function estimateLineHeights(cm) {
+    var doc = cm.doc, est = estimateHeight(cm);
+    doc.iter(function(line) {
+      var estHeight = est(line);
+      if (estHeight != line.height) updateLineHeight(line, estHeight);
+    });
+  }
+
+  function themeChanged(cm) {
+    cm.display.wrapper.className = cm.display.wrapper.className.replace(/\s*cm-s-\S+/g, "") +
+      cm.options.theme.replace(/(^|\s)\s*/g, " cm-s-");
+    clearCaches(cm);
+  }
+
+  function guttersChanged(cm) {
+    updateGutters(cm);
+    regChange(cm);
+    setTimeout(function(){alignHorizontally(cm);}, 20);
+  }
+
+  // Rebuild the gutter elements, ensure the margin to the left of the
+  // code matches their width.
+  function updateGutters(cm) {
+    var gutters = cm.display.gutters, specs = cm.options.gutters;
+    removeChildren(gutters);
+    for (var i = 0; i < specs.length; ++i) {
+      var gutterClass = specs[i];
+      var gElt = gutters.appendChild(elt("div", null, "CodeMirror-gutter " + gutterClass));
+      if (gutterClass == "CodeMirror-linenumbers") {
+        cm.display.lineGutter = gElt;
+        gElt.style.width = (cm.display.lineNumWidth || 1) + "px";
+      }
+    }
+    gutters.style.display = i ? "" : "none";
+    updateGutterSpace(cm);
+  }
+
+  function updateGutterSpace(cm) {
+    var width = cm.display.gutters.offsetWidth;
+    cm.display.sizer.style.marginLeft = width + "px";
+  }
+
+  // Compute the character length of a line, taking into account
+  // collapsed ranges (see markText) that might hide parts, and join
+  // other lines onto it.
+  function lineLength(line) {
+    if (line.height == 0) return 0;
+    var len = line.text.length, merged, cur = line;
+    while (merged = collapsedSpanAtStart(cur)) {
+      var found = merged.find(0, true);
+      cur = found.from.line;
+      len += found.from.ch - found.to.ch;
+    }
+    cur = line;
+    while (merged = collapsedSpanAtEnd(cur)) {
+      var found = merged.find(0, true);
+      len -= cur.text.length - found.from.ch;
+      cur = found.to.line;
+      len += cur.text.length - found.to.ch;
+    }
+    return len;
+  }
+
+  // Find the longest line in the document.
+  function findMaxLine(cm) {
+    var d = cm.display, doc = cm.doc;
+    d.maxLine = getLine(doc, doc.first);
+    d.maxLineLength = lineLength(d.maxLine);
+    d.maxLineChanged = true;
+    doc.iter(function(line) {
+      var len = lineLength(line);
+      if (len > d.maxLineLength) {
+        d.maxLineLength = len;
+        d.maxLine = line;
+      }
+    });
+  }
+
+  // Make sure the gutters options contains the element
+  // "CodeMirror-linenumbers" when the lineNumbers option is true.
+  function setGuttersForLineNumbers(options) {
+    var found = indexOf(options.gutters, "CodeMirror-linenumbers");
+    if (found == -1 && options.lineNumbers) {
+      options.gutters = options.gutters.concat(["CodeMirror-linenumbers"]);
+    } else if (found > -1 && !options.lineNumbers) {
+      options.gutters = options.gutters.slice(0);
+      options.gutters.splice(found, 1);
+    }
+  }
+
+  // SCROLLBARS
+
+  // Prepare DOM reads needed to update the scrollbars. Done in one
+  // shot to minimize update/measure roundtrips.
+  function measureForScrollbars(cm) {
+    var d = cm.display, gutterW = d.gutters.offsetWidth;
+    var docH = Math.round(cm.doc.height + paddingVert(cm.display));
+    return {
+      clientHeight: d.scroller.clientHeight,
+      viewHeight: d.wrapper.clientHeight,
+      scrollWidth: d.scroller.scrollWidth, clientWidth: d.scroller.clientWidth,
+      viewWidth: d.wrapper.clientWidth,
+      barLeft: cm.options.fixedGutter ? gutterW : 0,
+      docHeight: docH,
+      scrollHeight: docH + scrollGap(cm) + d.barHeight,
+      nativeBarWidth: d.nativeBarWidth,
+      gutterWidth: gutterW
+    };
+  }
+
+  function NativeScrollbars(place, scroll, cm) {
+    this.cm = cm;
+    var vert = this.vert = elt("div", [elt("div", null, null, "min-width: 1px")], "CodeMirror-vscrollbar");
+    var horiz = this.horiz = elt("div", [elt("div", null, null, "height: 100%; min-height: 1px")], "CodeMirror-hscrollbar");
+    place(vert); place(horiz);
+
+    on(vert, "scroll", function() {
+      if (vert.clientHeight) scroll(vert.scrollTop, "vertical");
+    });
+    on(horiz, "scroll", function() {
+      if (horiz.clientWidth) scroll(horiz.scrollLeft, "horizontal");
+    });
+
+    this.checkedOverlay = false;
+    // Need to set a minimum width to see the scrollbar on IE7 (but must not set it on IE8).
+    if (ie && ie_version < 8) this.horiz.style.minHeight = this.vert.style.minWidth = "18px";
+  }
+
+  NativeScrollbars.prototype = copyObj({
+    update: function(measure) {
+      var needsH = measure.scrollWidth > measure.clientWidth + 1;
+      var needsV = measure.scrollHeight > measure.clientHeight + 1;
+      var sWidth = measure.nativeBarWidth;
+
+      if (needsV) {
+        this.vert.style.display = "block";
+        this.vert.style.bottom = needsH ? sWidth + "px" : "0";
+        var totalHeight = measure.viewHeight - (needsH ? sWidth : 0);
+        // A bug in IE8 can cause this value to be negative, so guard it.
+        this.vert.firstChild.style.height =
+          Math.max(0, measure.scrollHeight - measure.clientHeight + totalHeight) + "px";
+      } else {
+        this.vert.style.display = "";
+        this.vert.firstChild.style.height = "0";
+      }
+
+      if (needsH) {
+        this.horiz.style.display = "block";
+        this.horiz.style.right = needsV ? sWidth + "px" : "0";
+        this.horiz.style.left = measure.barLeft + "px";
+        var totalWidth = measure.viewWidth - measure.barLeft - (needsV ? sWidth : 0);
+        this.horiz.firstChild.style.width =
+          (measure.scrollWidth - measure.clientWidth + totalWidth) + "px";
+      } else {
+        this.horiz.style.display = "";
+        this.horiz.firstChild.style.width = "0";
+      }
+
+      if (!this.checkedOverlay && measure.clientHeight > 0) {
+        if (sWidth == 0) this.overlayHack();
+        this.checkedOverlay = true;
+      }
+
+      return {right: needsV ? sWidth : 0, bottom: needsH ? sWidth : 0};
+    },
+    setScrollLeft: function(pos) {
+      if (this.horiz.scrollLeft != pos) this.horiz.scrollLeft = pos;
+    },
+    setScrollTop: function(pos) {
+      if (this.vert.scrollTop != pos) this.vert.scrollTop = pos;
+    },
+    overlayHack: function() {
+      var w = mac && !mac_geMountainLion ? "12px" : "18px";
+      this.horiz.style.minHeight = this.vert.style.minWidth = w;
+      var self = this;
+      var barMouseDown = function(e) {
+        if (e_target(e) != self.vert && e_target(e) != self.horiz)
+          operation(self.cm, onMouseDown)(e);
+      };
+      on(this.vert, "mousedown", barMouseDown);
+      on(this.horiz, "mousedown", barMouseDown);
+    },
+    clear: function() {
+      var parent = this.horiz.parentNode;
+      parent.removeChild(this.horiz);
+      parent.removeChild(this.vert);
+    }
+  }, NativeScrollbars.prototype);
+
+  function NullScrollbars() {}
+
+  NullScrollbars.prototype = copyObj({
+    update: function() { return {bottom: 0, right: 0}; },
+    setScrollLeft: function() {},
+    setScrollTop: function() {},
+    clear: function() {}
+  }, NullScrollbars.prototype);
+
+  CodeMirror.scrollbarModel = {"native": NativeScrollbars, "null": NullScrollbars};
+
+  function initScrollbars(cm) {
+    if (cm.display.scrollbars) {
+      cm.display.scrollbars.clear();
+      if (cm.display.scrollbars.addClass)
+        rmClass(cm.display.wrapper, cm.display.scrollbars.addClass);
+    }
+
+    cm.display.scrollbars = new CodeMirror.scrollbarModel[cm.options.scrollbarStyle](function(node) {
+      cm.display.wrapper.insertBefore(node, cm.display.scrollbarFiller);
+      // Prevent clicks in the scrollbars from killing focus
+      on(node, "mousedown", function() {
+        if (cm.state.focused) setTimeout(function() { cm.display.input.focus(); }, 0);
+      });
+      node.setAttribute("cm-not-content", "true");
+    }, function(pos, axis) {
+      if (axis == "horizontal") setScrollLeft(cm, pos);
+      else setScrollTop(cm, pos);
+    }, cm);
+    if (cm.display.scrollbars.addClass)
+      addClass(cm.display.wrapper, cm.display.scrollbars.addClass);
+  }
+
+  function updateScrollbars(cm, measure) {
+    if (!measure) measure = measureForScrollbars(cm);
+    var startWidth = cm.display.barWidth, startHeight = cm.display.barHeight;
+    updateScrollbarsInner(cm, measure);
+    for (var i = 0; i < 4 && startWidth != cm.display.barWidth || startHeight != cm.display.barHeight; i++) {
+      if (startWidth != cm.display.barWidth && cm.options.lineWrapping)
+        updateHeightsInViewport(cm);
+      updateScrollbarsInner(cm, measureForScrollbars(cm));
+      startWidth = cm.display.barWidth; startHeight = cm.display.barHeight;
+    }
+  }
+
+  // Re-synchronize the fake scrollbars with the actual size of the
+  // content.
+  function updateScrollbarsInner(cm, measure) {
+    var d = cm.display;
+    var sizes = d.scrollbars.update(measure);
+
+    d.sizer.style.paddingRight = (d.barWidth = sizes.right) + "px";
+    d.sizer.style.paddingBottom = (d.barHeight = sizes.bottom) + "px";
+
+    if (sizes.right && sizes.bottom) {
+      d.scrollbarFiller.style.display = "block";
+      d.scrollbarFiller.style.height = sizes.bottom + "px";
+      d.scrollbarFiller.style.width = sizes.right + "px";
+    } else d.scrollbarFiller.style.display = "";
+    if (sizes.bottom && cm.options.coverGutterNextToScrollbar && cm.options.fixedGutter) {
+      d.gutterFiller.style.display = "block";
+      d.gutterFiller.style.height = sizes.bottom + "px";
+      d.gutterFiller.style.width = measure.gutterWidth + "px";
+    } else d.gutterFiller.style.display = "";
+  }
+
+  // Compute the lines that are visible in a given viewport (defaults
+  // the the current scroll position). viewport may contain top,
+  // height, and ensure (see op.scrollToPos) properties.
+  function visibleLines(display, doc, viewport) {
+    var top = viewport && viewport.top != null ? Math.max(0, viewport.top) : display.scroller.scrollTop;
+    top = Math.floor(top - paddingTop(display));
+    var bottom = viewport && viewport.bottom != null ? viewport.bottom : top + display.wrapper.clientHeight;
+
+    var from = lineAtHeight(doc, top), to = lineAtHeight(doc, bottom);
+    // Ensure is a {from: {line, ch}, to: {line, ch}} object, and
+    // forces those lines into the viewport (if possible).
+    if (viewport && viewport.ensure) {
+      var ensureFrom = viewport.ensure.from.line, ensureTo = viewport.ensure.to.line;
+      if (ensureFrom < from) {
+        from = ensureFrom;
+        to = lineAtHeight(doc, heightAtLine(getLine(doc, ensureFrom)) + display.wrapper.clientHeight);
+      } else if (Math.min(ensureTo, doc.lastLine()) >= to) {
+        from = lineAtHeight(doc, heightAtLine(getLine(doc, ensureTo)) - display.wrapper.clientHeight);
+        to = ensureTo;
+      }
+    }
+    return {from: from, to: Math.max(to, from + 1)};
+  }
+
+  // LINE NUMBERS
+
+  // Re-align line numbers and gutter marks to compensate for
+  // horizontal scrolling.
+  function alignHorizontally(cm) {
+    var display = cm.display, view = display.view;
+    if (!display.alignWidgets && (!display.gutters.firstChild || !cm.options.fixedGutter)) return;
+    var comp = compensateForHScroll(display) - display.scroller.scrollLeft + cm.doc.scrollLeft;
+    var gutterW = display.gutters.offsetWidth, left = comp + "px";
+    for (var i = 0; i < view.length; i++) if (!view[i].hidden) {
+      if (cm.options.fixedGutter && view[i].gutter)
+        view[i].gutter.style.left = left;
+      var align = view[i].alignable;
+      if (align) for (var j = 0; j < align.length; j++)
+        align[j].style.left = left;
+    }
+    if (cm.options.fixedGutter)
+      display.gutters.style.left = (comp + gutterW) + "px";
+  }
+
+  // Used to ensure that the line number gutter is still the right
+  // size for the current document size. Returns true when an update
+  // is needed.
+  function maybeUpdateLineNumberWidth(cm) {
+    if (!cm.options.lineNumbers) return false;
+    var doc = cm.doc, last = lineNumberFor(cm.options, doc.first + doc.size - 1), display = cm.display;
+    if (last.length != display.lineNumChars) {
+      var test = display.measure.appendChild(elt("div", [elt("div", last)],
+                                                 "CodeMirror-linenumber CodeMirror-gutter-elt"));
+      var innerW = test.firstChild.offsetWidth, padding = test.offsetWidth - innerW;
+      display.lineGutter.style.width = "";
+      display.lineNumInnerWidth = Math.max(innerW, display.lineGutter.offsetWidth - padding) + 1;
+      display.lineNumWidth = display.lineNumInnerWidth + padding;
+      display.lineNumChars = display.lineNumInnerWidth ? last.length : -1;
+      display.lineGutter.style.width = display.lineNumWidth + "px";
+      updateGutterSpace(cm);
+      return true;
+    }
+    return false;
+  }
+
+  function lineNumberFor(options, i) {
+    return String(options.lineNumberFormatter(i + options.firstLineNumber));
+  }
+
+  // Computes display.scroller.scrollLeft + display.gutters.offsetWidth,
+  // but using getBoundingClientRect to get a sub-pixel-accurate
+  // result.
+  function compensateForHScroll(display) {
+    return display.scroller.getBoundingClientRect().left - display.sizer.getBoundingClientRect().left;
+  }
+
+  // DISPLAY DRAWING
+
+  function DisplayUpdate(cm, viewport, force) {
+    var display = cm.display;
+
+    this.viewport = viewport;
+    // Store some values that we'll need later (but don't want to force a relayout for)
+    this.visible = visibleLines(display, cm.doc, viewport);
+    this.editorIsHidden = !display.wrapper.offsetWidth;
+    this.wrapperHeight = display.wrapper.clientHeight;
+    this.wrapperWidth = display.wrapper.clientWidth;
+    this.oldDisplayWidth = displayWidth(cm);
+    this.force = force;
+    this.dims = getDimensions(cm);
+    this.events = [];
+  }
+
+  DisplayUpdate.prototype.signal = function(emitter, type) {
+    if (hasHandler(emitter, type))
+      this.events.push(arguments);
+  };
+  DisplayUpdate.prototype.finish = function() {
+    for (var i = 0; i < this.events.length; i++)
+      signal.apply(null, this.events[i]);
+  };
+
+  function maybeClipScrollbars(cm) {
+    var display = cm.display;
+    if (!display.scrollbarsClipped && display.scroller.offsetWidth) {
+      display.nativeBarWidth = display.scroller.offsetWidth - display.scroller.clientWidth;
+      display.heightForcer.style.height = scrollGap(cm) + "px";
+      display.sizer.style.marginBottom = -display.nativeBarWidth + "px";
+      display.sizer.style.borderRightWidth = scrollGap(cm) + "px";
+      display.scrollbarsClipped = true;
+    }
+  }
+
+  // Does the actual updating of the line display. Bails out
+  // (returning false) when there is nothing to be done and forced is
+  // false.
+  function updateDisplayIfNeeded(cm, update) {
+    var display = cm.display, doc = cm.doc;
+
+    if (update.editorIsHidden) {
+      resetView(cm);
+      return false;
+    }
+
+    // Bail out if the visible area is already rendered and nothing changed.
+    if (!update.force &&
+        update.visible.from >= display.viewFrom && update.visible.to <= display.viewTo &&
+        (display.updateLineNumbers == null || display.updateLineNumbers >= display.viewTo) &&
+        display.renderedView == display.view && countDirtyView(cm) == 0)
+      return false;
+
+    if (maybeUpdateLineNumberWidth(cm)) {
+      resetView(cm);
+      update.dims = getDimensions(cm);
+    }
+
+    // Compute a suitable new viewport (from & to)
+    var end = doc.first + doc.size;
+    var from = Math.max(update.visible.from - cm.options.viewportMargin, doc.first);
+    var to = Math.min(end, update.visible.to + cm.options.viewportMargin);
+    if (display.viewFrom < from && from - display.viewFrom < 20) from = Math.max(doc.first, display.viewFrom);
+    if (display.viewTo > to && display.viewTo - to < 20) to = Math.min(end, display.viewTo);
+    if (sawCollapsedSpans) {
+      from = visualLineNo(cm.doc, from);
+      to = visualLineEndNo(cm.doc, to);
+    }
+
+    var different = from != display.viewFrom || to != display.viewTo ||
+      display.lastWrapHeight != update.wrapperHeight || display.lastWrapWidth != update.wrapperWidth;
+    adjustView(cm, from, to);
+
+    display.viewOffset = heightAtLine(getLine(cm.doc, display.viewFrom));
+    // Position the mover div to align with the current scroll position
+    cm.display.mover.style.top = display.viewOffset + "px";
+
+    var toUpdate = countDirtyView(cm);
+    if (!different && toUpdate == 0 && !update.force && display.renderedView == display.view &&
+        (display.updateLineNumbers == null || display.updateLineNumbers >= display.viewTo))
+      return false;
+
+    // For big changes, we hide the enclosing element during the
+    // update, since that speeds up the operations on most browsers.
+    var focused = activeElt();
+    if (toUpdate > 4) display.lineDiv.style.display = "none";
+    patchDisplay(cm, display.updateLineNumbers, update.dims);
+    if (toUpdate > 4) display.lineDiv.style.display = "";
+    display.renderedView = display.view;
+    // There might have been a widget with a focused element that got
+    // hidden or updated, if so re-focus it.
+    if (focused && activeElt() != focused && focused.offsetHeight) focused.focus();
+
+    // Prevent selection and cursors from interfering with the scroll
+    // width and height.
+    removeChildren(display.cursorDiv);
+    removeChildren(display.selectionDiv);
+    display.gutters.style.height = 0;
+
+    if (different) {
+      display.lastWrapHeight = update.wrapperHeight;
+      display.lastWrapWidth = update.wrapperWidth;
+      startWorker(cm, 400);
+    }
+
+    display.updateLineNumbers = null;
+
+    return true;
+  }
+
+  function postUpdateDisplay(cm, update) {
+    var viewport = update.viewport;
+    for (var first = true;; first = false) {
+      if (!first || !cm.options.lineWrapping || update.oldDisplayWidth == displayWidth(cm)) {
+        // Clip forced viewport to actual scrollable area.
+        if (viewport && viewport.top != null)
+          viewport = {top: Math.min(cm.doc.height + paddingVert(cm.display) - displayHeight(cm), viewport.top)};
+        // Updated line heights might result in the drawn area not
+        // actually covering the viewport. Keep looping until it does.
+        update.visible = visibleLines(cm.display, cm.doc, viewport);
+        if (update.visible.from >= cm.display.viewFrom && update.visible.to <= cm.display.viewTo)
+          break;
+      }
+      if (!updateDisplayIfNeeded(cm, update)) break;
+      updateHeightsInViewport(cm);
+      var barMeasure = measureForScrollbars(cm);
+      updateSelection(cm);
+      setDocumentHeight(cm, barMeasure);
+      updateScrollbars(cm, barMeasure);
+    }
+
+    update.signal(cm, "update", cm);
+    if (cm.display.viewFrom != cm.display.reportedViewFrom || cm.display.viewTo != cm.display.reportedViewTo) {
+      update.signal(cm, "viewportChange", cm, cm.display.viewFrom, cm.display.viewTo);
+      cm.display.reportedViewFrom = cm.display.viewFrom; cm.display.reportedViewTo = cm.display.viewTo;
+    }
+  }
+
+  function updateDisplaySimple(cm, viewport) {
+    var update = new DisplayUpdate(cm, viewport);
+    if (updateDisplayIfNeeded(cm, update)) {
+      updateHeightsInViewport(cm);
+      postUpdateDisplay(cm, update);
+      var barMeasure = measureForScrollbars(cm);
+      updateSelection(cm);
+      setDocumentHeight(cm, barMeasure);
+      updateScrollbars(cm, barMeasure);
+      update.finish();
+    }
+  }
+
+  function setDocumentHeight(cm, measure) {
+    cm.display.sizer.style.minHeight = measure.docHeight + "px";
+    var total = measure.docHeight + cm.display.barHeight;
+    cm.display.heightForcer.style.top = total + "px";
+    cm.display.gutters.style.height = Math.max(total + scrollGap(cm), measure.clientHeight) + "px";
+  }
+
+  // Read the actual heights of the rendered lines, and update their
+  // stored heights to match.
+  function updateHeightsInViewport(cm) {
+    var display = cm.display;
+    var prevBottom = display.lineDiv.offsetTop;
+    for (var i = 0; i < display.view.length; i++) {
+      var cur = display.view[i], height;
+      if (cur.hidden) continue;
+      if (ie && ie_version < 8) {
+        var bot = cur.node.offsetTop + cur.node.offsetHeight;
+        height = bot - prevBottom;
+        prevBottom = bot;
+      } else {
+        var box = cur.node.getBoundingClientRect();
+        height = box.bottom - box.top;
+      }
+      var diff = cur.line.height - height;
+      if (height < 2) height = textHeight(display);
+      if (diff > .001 || diff < -.001) {
+        updateLineHeight(cur.line, height);
+        updateWidgetHeight(cur.line);
+        if (cur.rest) for (var j = 0; j < cur.rest.length; j++)
+          updateWidgetHeight(cur.rest[j]);
+      }
+    }
+  }
+
+  // Read and store the height of line widgets associated with the
+  // given line.
+  function updateWidgetHeight(line) {
+    if (line.widgets) for (var i = 0; i < line.widgets.length; ++i)
+      line.widgets[i].height = line.widgets[i].node.offsetHeight;
+  }
+
+  // Do a bulk-read of the DOM positions and sizes needed to draw the
+  // view, so that we don't interleave reading and writing to the DOM.
+  function getDimensions(cm) {
+    var d = cm.display, left = {}, width = {};
+    var gutterLeft = d.gutters.clientLeft;
+    for (var n = d.gutters.firstChild, i = 0; n; n = n.nextSibling, ++i) {
+      left[cm.options.gutters[i]] = n.offsetLeft + n.clientLeft + gutterLeft;
+      width[cm.options.gutters[i]] = n.clientWidth;
+    }
+    return {fixedPos: compensateForHScroll(d),
+            gutterTotalWidth: d.gutters.offsetWidth,
+            gutterLeft: left,
+            gutterWidth: width,
+            wrapperWidth: d.wrapper.clientWidth};
+  }
+
+  // Sync the actual display DOM structure with display.view, removing
+  // nodes for lines that are no longer in view, and creating the ones
+  // that are not there yet, and updating the ones that are out of
+  // date.
+  function patchDisplay(cm, updateNumbersFrom, dims) {
+    var display = cm.display, lineNumbers = cm.options.lineNumbers;
+    var container = display.lineDiv, cur = container.firstChild;
+
+    function rm(node) {
+      var next = node.nextSibling;
+      // Works around a throw-scroll bug in OS X Webkit
+      if (webkit && mac && cm.display.currentWheelTarget == node)
+        node.style.display = "none";
+      else
+        node.parentNode.removeChild(node);
+      return next;
+    }
+
+    var view = display.view, lineN = display.viewFrom;
+    // Loop over the elements in the view, syncing cur (the DOM nodes
+    // in display.lineDiv) with the view as we go.
+    for (var i = 0; i < view.length; i++) {
+      var lineView = view[i];
+      if (lineView.hidden) {
+      } else if (!lineView.node || lineView.node.parentNode != container) { // Not drawn yet
+        var node = buildLineElement(cm, lineView, lineN, dims);
+        container.insertBefore(node, cur);
+      } else { // Already drawn
+        while (cur != lineView.node) cur = rm(cur);
+        var updateNumber = lineNumbers && updateNumbersFrom != null &&
+          updateNumbersFrom <= lineN && lineView.lineNumber;
+        if (lineView.changes) {
+          if (indexOf(lineView.changes, "gutter") > -1) updateNumber = false;
+          updateLineForChanges(cm, lineView, lineN, dims);
+        }
+        if (updateNumber) {
+          removeChildren(lineView.lineNumber);
+          lineView.lineNumber.appendChild(document.createTextNode(lineNumberFor(cm.options, lineN)));
+        }
+        cur = lineView.node.nextSibling;
+      }
+      lineN += lineView.size;
+    }
+    while (cur) cur = rm(cur);
+  }
+
+  // When an aspect of a line changes, a string is added to
+  // lineView.changes. This updates the relevant part of the line's
+  // DOM structure.
+  function updateLineForChanges(cm, lineView, lineN, dims) {
+    for (var j = 0; j < lineView.changes.length; j++) {
+      var type = lineView.changes[j];
+      if (type == "text") updateLineText(cm, lineView);
+      else if (type == "gutter") updateLineGutter(cm, lineView, lineN, dims);
+      else if (type == "class") updateLineClasses(lineView);
+      else if (type == "widget") updateLineWidgets(cm, lineView, dims);
+    }
+    lineView.changes = null;
+  }
+
+  // Lines with gutter elements, widgets or a background class need to
+  // be wrapped, and have the extra elements added to the wrapper div
+  function ensureLineWrapped(lineView) {
+    if (lineView.node == lineView.text) {
+      lineView.node = elt("div", null, null, "position: relative");
+      if (lineView.text.parentNode)
+        lineView.text.parentNode.replaceChild(lineView.node, lineView.text);
+      lineView.node.appendChild(lineView.text);
+      if (ie && ie_version < 8) lineView.node.style.zIndex = 2;
+    }
+    return lineView.node;
+  }
+
+  function updateLineBackground(lineView) {
+    var cls = lineView.bgClass ? lineView.bgClass + " " + (lineView.line.bgClass || "") : lineView.line.bgClass;
+    if (cls) cls += " CodeMirror-linebackground";
+    if (lineView.background) {
+      if (cls) lineView.background.className = cls;
+      else { lineView.background.parentNode.removeChild(lineView.background); lineView.background = null; }
+    } else if (cls) {
+      var wrap = ensureLineWrapped(lineView);
+      lineView.background = wrap.insertBefore(elt("div", null, cls), wrap.firstChild);
+    }
+  }
+
+  // Wrapper around buildLineContent which will reuse the structure
+  // in display.externalMeasured when possible.
+  function getLineContent(cm, lineView) {
+    var ext = cm.display.externalMeasured;
+    if (ext && ext.line == lineView.line) {
+      cm.display.externalMeasured = null;
+      lineView.measure = ext.measure;
+      return ext.built;
+    }
+    return buildLineContent(cm, lineView);
+  }
+
+  // Redraw the line's text. Interacts with the background and text
+  // classes because the mode may output tokens that influence these
+  // classes.
+  function updateLineText(cm, lineView) {
+    var cls = lineView.text.className;
+    var built = getLineContent(cm, lineView);
+    if (lineView.text == lineView.node) lineView.node = built.pre;
+    lineView.text.parentNode.replaceChild(built.pre, lineView.text);
+    lineView.text = built.pre;
+    if (built.bgClass != lineView.bgClass || built.textClass != lineView.textClass) {
+      lineView.bgClass = built.bgClass;
+      lineView.textClass = built.textClass;
+      updateLineClasses(lineView);
+    } else if (cls) {
+      lineView.text.className = cls;
+    }
+  }
+
+  function updateLineClasses(lineView) {
+    updateLineBackground(lineView);
+    if (lineView.line.wrapClass)
+      ensureLineWrapped(lineView).className = lineView.line.wrapClass;
+    else if (lineView.node != lineView.text)
+      lineView.node.className = "";
+    var textClass = lineView.textClass ? lineView.textClass + " " + (lineView.line.textClass || "") : lineView.line.textClass;
+    lineView.text.className = textClass || "";
+  }
+
+  function updateLineGutter(cm, lineView, lineN, dims) {
+    if (lineView.gutter) {
+      lineView.node.removeChild(lineView.gutter);
+      lineView.gutter = null;
+    }
+    var markers = lineView.line.gutterMarkers;
+    if (cm.options.lineNumbers || markers) {
+      var wrap = ensureLineWrapped(lineView);
+      var gutterWrap = lineView.gutter = elt("div", null, "CodeMirror-gutter-wrapper", "left: " +
+                                             (cm.options.fixedGutter ? dims.fixedPos : -dims.gutterTotalWidth) +
+                                             "px; width: " + dims.gutterTotalWidth + "px");
+      cm.display.input.setUneditable(gutterWrap);
+      wrap.insertBefore(gutterWrap, lineView.text);
+      if (lineView.line.gutterClass)
+        gutterWrap.className += " " + lineView.line.gutterClass;
+      if (cm.options.lineNumbers && (!markers || !markers["CodeMirror-linenumbers"]))
+        lineView.lineNumber = gutterWrap.appendChild(
+          elt("div", lineNumberFor(cm.options, lineN),
+              "CodeMirror-linenumber CodeMirror-gutter-elt",
+              "left: " + dims.gutterLeft["CodeMirror-linenumbers"] + "px; width: "
+              + cm.display.lineNumInnerWidth + "px"));
+      if (markers) for (var k = 0; k < cm.options.gutters.length; ++k) {
+        var id = cm.options.gutters[k], found = markers.hasOwnProperty(id) && markers[id];
+        if (found)
+          gutterWrap.appendChild(elt("div", [found], "CodeMirror-gutter-elt", "left: " +
+                                     dims.gutterLeft[id] + "px; width: " + dims.gutterWidth[id] + "px"));
+      }
+    }
+  }
+
+  function updateLineWidgets(cm, lineView, dims) {
+    if (lineView.alignable) lineView.alignable = null;
+    for (var node = lineView.node.firstChild, next; node; node = next) {
+      var next = node.nextSibling;
+      if (node.className == "CodeMirror-linewidget")
+        lineView.node.removeChild(node);
+    }
+    insertLineWidgets(cm, lineView, dims);
+  }
+
+  // Build a line's DOM representation from scratch
+  function buildLineElement(cm, lineView, lineN, dims) {
+    var built = getLineContent(cm, lineView);
+    lineView.text = lineView.node = built.pre;
+    if (built.bgClass) lineView.bgClass = built.bgClass;
+    if (built.textClass) lineView.textClass = built.textClass;
+
+    updateLineClasses(lineView);
+    updateLineGutter(cm, lineView, lineN, dims);
+    insertLineWidgets(cm, lineView, dims);
+    return lineView.node;
+  }
+
+  // A lineView may contain multiple logical lines (when merged by
+  // collapsed spans). The widgets for all of them need to be drawn.
+  function insertLineWidgets(cm, lineView, dims) {
+    insertLineWidgetsFor(cm, lineView.line, lineView, dims, true);
+    if (lineView.rest) for (var i = 0; i < lineView.rest.length; i++)
+      insertLineWidgetsFor(cm, lineView.rest[i], lineView, dims, false);
+  }
+
+  function insertLineWidgetsFor(cm, line, lineView, dims, allowAbove) {
+    if (!line.widgets) return;
+    var wrap = ensureLineWrapped(lineView);
+    for (var i = 0, ws = line.widgets; i < ws.length; ++i) {
+      var widget = ws[i], node = elt("div", [widget.node], "CodeMirror-linewidget");
+      if (!widget.handleMouseEvents) node.setAttribute("cm-ignore-events", "true");
+      positionLineWidget(widget, node, lineView, dims);
+      cm.display.input.setUneditable(node);
+      if (allowAbove && widget.above)
+        wrap.insertBefore(node, lineView.gutter || lineView.text);
+      else
+        wrap.appendChild(node);
+      signalLater(widget, "redraw");
+    }
+  }
+
+  function positionLineWidget(widget, node, lineView, dims) {
+    if (widget.noHScroll) {
+      (lineView.alignable || (lineView.alignable = [])).push(node);
+      var width = dims.wrapperWidth;
+      node.style.left = dims.fixedPos + "px";
+      if (!widget.coverGutter) {
+        width -= dims.gutterTotalWidth;
+        node.style.paddingLeft = dims.gutterTotalWidth + "px";
+      }
+      node.style.width = width + "px";
+    }
+    if (widget.coverGutter) {
+      node.style.zIndex = 5;
+      node.style.position = "relative";
+      if (!widget.noHScroll) node.style.marginLeft = -dims.gutterTotalWidth + "px";
+    }
+  }
+
+  // POSITION OBJECT
+
+  // A Pos instance represents a position within the text.
+  var Pos = CodeMirror.Pos = function(line, ch) {
+    if (!(this instanceof Pos)) return new Pos(line, ch);
+    this.line = line; this.ch = ch;
+  };
+
+  // Compare two positions, return 0 if they are the same, a negative
+  // number when a is less, and a positive number otherwise.
+  var cmp = CodeMirror.cmpPos = function(a, b) { return a.line - b.line || a.ch - b.ch; };
+
+  function copyPos(x) {return Pos(x.line, x.ch);}
+  function maxPos(a, b) { return cmp(a, b) < 0 ? b : a; }
+  function minPos(a, b) { return cmp(a, b) < 0 ? a : b; }
+
+  // INPUT HANDLING
+
+  function ensureFocus(cm) {
+    if (!cm.state.focused) { cm.display.input.focus(); onFocus(cm); }
+  }
+
+  function isReadOnly(cm) {
+    return cm.options.readOnly || cm.doc.cantEdit;
+  }
+
+  // This will be set to an array of strings when copying, so that,
+  // when pasting, we know what kind of selections the copied text
+  // was made out of.
+  var lastCopied = null;
+
+  function applyTextInput(cm, inserted, deleted, sel, origin) {
+    var doc = cm.doc;
+    cm.display.shift = false;
+    if (!sel) sel = doc.sel;
+
+    var textLines = splitLines(inserted), multiPaste = null;
+    // When pasing N lines into N selections, insert one line per selection
+    if (cm.state.pasteIncoming && sel.ranges.length > 1) {
+      if (lastCopied && lastCopied.join("\n") == inserted)
+        multiPaste = sel.ranges.length % lastCopied.length == 0 && map(lastCopied, splitLines);
+      else if (textLines.length == sel.ranges.length)
+        multiPaste = map(textLines, function(l) { return [l]; });
+    }
+
+    // Normal behavior is to insert the new text into every selection
+    for (var i = sel.ranges.length - 1; i >= 0; i--) {
+      var range = sel.ranges[i];
+      var from = range.from(), to = range.to();
+      if (range.empty()) {
+        if (deleted && deleted > 0) // Handle deletion
+          from = Pos(from.line, from.ch - deleted);
+        else if (cm.state.overwrite && !cm.state.pasteIncoming) // Handle overwrite
+          to = Pos(to.line, Math.min(getLine(doc, to.line).text.length, to.ch + lst(textLines).length));
+      }
+      var updateInput = cm.curOp.updateInput;
+      var changeEvent = {from: from, to: to, text: multiPaste ? multiPaste[i % multiPaste.length] : textLines,
+                         origin: origin || (cm.state.pasteIncoming ? "paste" : cm.state.cutIncoming ? "cut" : "+input")};
+      makeChange(cm.doc, changeEvent);
+      signalLater(cm, "inputRead", cm, changeEvent);
+    }
+    if (inserted && !cm.state.pasteIncoming)
+      triggerElectric(cm, inserted);
+
+    ensureCursorVisible(cm);
+    cm.curOp.updateInput = updateInput;
+    cm.curOp.typing = true;
+    cm.state.pasteIncoming = cm.state.cutIncoming = false;
+  }
+
+  function triggerElectric(cm, inserted) {
+    // When an 'electric' character is inserted, immediately trigger a reindent
+    if (!cm.options.electricChars || !cm.options.smartIndent) return;
+    var sel = cm.doc.sel;
+
+    for (var i = sel.ranges.length - 1; i >= 0; i--) {
+      var range = sel.ranges[i];
+      if (range.head.ch > 100 || (i && sel.ranges[i - 1].head.line == range.head.line)) continue;
+      var mode = cm.getModeAt(range.head);
+      var indented = false;
+      if (mode.electricChars) {
+        for (var j = 0; j < mode.electricChars.length; j++)
+          if (inserted.indexOf(mode.electricChars.charAt(j)) > -1) {
+            indented = indentLine(cm, range.head.line, "smart");
+            break;
+          }
+      } else if (mode.electricInput) {
+        if (mode.electricInput.test(getLine(cm.doc, range.head.line).text.slice(0, range.head.ch)))
+          indented = indentLine(cm, range.head.line, "smart");
+      }
+      if (indented) signalLater(cm, "electricInput", cm, range.head.line);
+    }
+  }
+
+  function copyableRanges(cm) {
+    var text = [], ranges = [];
+    for (var i = 0; i < cm.doc.sel.ranges.length; i++) {
+      var line = cm.doc.sel.ranges[i].head.line;
+      var lineRange = {anchor: Pos(line, 0), head: Pos(line + 1, 0)};
+      ranges.push(lineRange);
+      text.push(cm.getRange(lineRange.anchor, lineRange.head));
+    }
+    return {text: text, ranges: ranges};
+  }
+
+  function disableBrowserMagic(field) {
+    field.setAttribute("autocorrect", "off");
+    field.setAttribute("autocapitalize", "off");
+    field.setAttribute("spellcheck", "false");
+  }
+
+  // TEXTAREA INPUT STYLE
+
+  function TextareaInput(cm) {
+    this.cm = cm;
+    // See input.poll and input.reset
+    this.prevInput = "";
+
+    // Flag that indicates whether we expect input to appear real soon
+    // now (after some event like 'keypress' or 'input') and are
+    // polling intensively.
+    this.pollingFast = false;
+    // Self-resetting timeout for the poller
+    this.polling = new Delayed();
+    // Tracks when input.reset has punted to just putting a short
+    // string into the textarea instead of the full selection.
+    this.inaccurateSelection = false;
+    // Used to work around IE issue with selection being forgotten when focus moves away from textarea
+    this.hasSelection = false;
+    this.composing = null;
+  };
+
+  function hiddenTextarea() {
+    var te = elt("textarea", null, null, "position: absolute; padding: 0; width: 1px; height: 1em; outline: none");
+    var div = elt("div", [te], null, "overflow: hidden; position: relative; width: 3px; height: 0px;");
+    // The textarea is kept positioned near the cursor to prevent the
+    // fact that it'll be scrolled into view on input from scrolling
+    // our fake cursor out of view. On webkit, when wrap=off, paste is
+    // very slow. So make the area wide instead.
+    if (webkit) te.style.width = "1000px";
+    else te.setAttribute("wrap", "off");
+    // If border: 0; -- iOS fails to open keyboard (issue #1287)
+    if (ios) te.style.border = "1px solid black";
+    disableBrowserMagic(te);
+    return div;
+  }
+
+  TextareaInput.prototype = copyObj({
+    init: function(display) {
+      var input = this, cm = this.cm;
+
+      // Wraps and hides input textarea
+      var div = this.wrapper = hiddenTextarea();
+      // The semihidden textarea that is focused when the editor is
+      // focused, and receives input.
+      var te = this.textarea = div.firstChild;
+      display.wrapper.insertBefore(div, display.wrapper.firstChild);
+
+      // Needed to hide big blue blinking cursor on Mobile Safari (doesn't seem to work in iOS 8 anymore)
+      if (ios) te.style.width = "0px";
+
+      on(te, "input", function() {
+        if (ie && ie_version >= 9 && input.hasSelection) input.hasSelection = null;
+        input.poll();
+      });
+
+      on(te, "paste", function() {
+        // Workaround for webkit bug https://bugs.webkit.org/show_bug.cgi?id=90206
+        // Add a char to the end of textarea before paste occur so that
+        // selection doesn't span to the end of textarea.
+        if (webkit && !cm.state.fakedLastChar && !(new Date - cm.state.lastMiddleDown < 200)) {
+          var start = te.selectionStart, end = te.selectionEnd;
+          te.value += "$";
+          // The selection end needs to be set before the start, otherwise there
+          // can be an intermediate non-empty selection between the two, which
+          // can override the middle-click paste buffer on linux and cause the
+          // wrong thing to get pasted.
+          te.selectionEnd = end;
+          te.selectionStart = start;
+          cm.state.fakedLastChar = true;
+        }
+        cm.state.pasteIncoming = true;
+        input.fastPoll();
+      });
+
+      function prepareCopyCut(e) {
+        if (cm.somethingSelected()) {
+          lastCopied = cm.getSelections();
+          if (input.inaccurateSelection) {
+            input.prevInput = "";
+            input.inaccurateSelection = false;
+            te.value = lastCopied.join("\n");
+            selectInput(te);
+          }
+        } else if (!cm.options.lineWiseCopyCut) {
+          return;
+        } else {
+          var ranges = copyableRanges(cm);
+          lastCopied = ranges.text;
+          if (e.type == "cut") {
+            cm.setSelections(ranges.ranges, null, sel_dontScroll);
+          } else {
+            input.prevInput = "";
+            te.value = ranges.text.join("\n");
+            selectInput(te);
+          }
+        }
+        if (e.type == "cut") cm.state.cutIncoming = true;
+      }
+      on(te, "cut", prepareCopyCut);
+      on(te, "copy", prepareCopyCut);
+
+      on(display.scroller, "paste", function(e) {
+        if (eventInWidget(display, e)) return;
+        cm.state.pasteIncoming = true;
+        input.focus();
+      });
+
+      // Prevent normal selection in the editor (we handle our own)
+      on(display.lineSpace, "selectstart", function(e) {
+        if (!eventInWidget(display, e)) e_preventDefault(e);
+      });
+
+      on(te, "compositionstart", function() {
+        var start = cm.getCursor("from");
+        input.composing = {
+          start: start,
+          range: cm.markText(start, cm.getCursor("to"), {className: "CodeMirror-composing"})
+        };
+      });
+      on(te, "compositionend", function() {
+        if (input.composing) {
+          input.poll();
+          input.composing.range.clear();
+          input.composing = null;
+        }
+      });
+    },
+
+    prepareSelection: function() {
+      // Redraw the selection and/or cursor
+      var cm = this.cm, display = cm.display, doc = cm.doc;
+      var result = prepareSelection(cm);
+
+      // Move the hidden textarea near the cursor to prevent scrolling artifacts
+      if (cm.options.moveInputWithCursor) {
+        var headPos = cursorCoords(cm, doc.sel.primary().head, "div");
+        var wrapOff = display.wrapper.getBoundingClientRect(), lineOff = display.lineDiv.getBoundingClientRect();
+        result.teTop = Math.max(0, Math.min(display.wrapper.clientHeight - 10,
+                                            headPos.top + lineOff.top - wrapOff.top));
+        result.teLeft = Math.max(0, Math.min(display.wrapper.clientWidth - 10,
+                                             headPos.left + lineOff.left - wrapOff.left));
+      }
+
+      return result;
+    },
+
+    showSelection: function(drawn) {
+      var cm = this.cm, display = cm.display;
+      removeChildrenAndAdd(display.cursorDiv, drawn.cursors);
+      removeChildrenAndAdd(display.selectionDiv, drawn.selection);
+      if (drawn.teTop != null) {
+        this.wrapper.style.top = drawn.teTop + "px";
+        this.wrapper.style.left = drawn.teLeft + "px";
+      }
+    },
+
+    // Reset the input to correspond to the selection (or to be empty,
+    // when not typing and nothing is selected)
+    reset: function(typing) {
+      if (this.contextMenuPending) return;
+      var minimal, selected, cm = this.cm, doc = cm.doc;
+      if (cm.somethingSelected()) {
+        this.prevInput = "";
+        var range = doc.sel.primary();
+        minimal = hasCopyEvent &&
+          (range.to().line - range.from().line > 100 || (selected = cm.getSelection()).length > 1000);
+        var content = minimal ? "-" : selected || cm.getSelection();
+        this.textarea.value = content;
+        if (cm.state.focused) selectInput(this.textarea);
+        if (ie && ie_version >= 9) this.hasSelection = content;
+      } else if (!typing) {
+        this.prevInput = this.textarea.value = "";
+        if (ie && ie_version >= 9) this.hasSelection = null;
+      }
+      this.inaccurateSelection = minimal;
+    },
+
+    getField: function() { return this.textarea; },
+
+    supportsTouch: function() { return false; },
+
+    focus: function() {
+      if (this.cm.options.readOnly != "nocursor" && (!mobile || activeElt() != this.textarea)) {
+        try { this.textarea.focus(); }
+        catch (e) {} // IE8 will throw if the textarea is display: none or not in DOM
+      }
+    },
+
+    blur: function() { this.textarea.blur(); },
+
+    resetPosition: function() {
+      this.wrapper.style.top = this.wrapper.style.left = 0;
+    },
+
+    receivedFocus: function() { this.slowPoll(); },
+
+    // Poll for input changes, using the normal rate of polling. This
+    // runs as long as the editor is focused.
+    slowPoll: function() {
+      var input = this;
+      if (input.pollingFast) return;
+      input.polling.set(this.cm.options.pollInterval, function() {
+        input.poll();
+        if (input.cm.state.focused) input.slowPoll();
+      });
+    },
+
+    // When an event has just come in that is likely to add or change
+    // something in the input textarea, we poll faster, to ensure that
+    // the change appears on the screen quickly.
+    fastPoll: function() {
+      var missed = false, input = this;
+      input.pollingFast = true;
+      function p() {
+        var changed = input.poll();
+        if (!changed && !missed) {missed = true; input.polling.set(60, p);}
+        else {input.pollingFast = false; input.slowPoll();}
+      }
+      input.polling.set(20, p);
+    },
+
+    // Read input from the textarea, and update the document to match.
+    // When something is selected, it is present in the textarea, and
+    // selected (unless it is huge, in which case a placeholder is
+    // used). When nothing is selected, the cursor sits after previously
+    // seen text (can be empty), which is stored in prevInput (we must
+    // not reset the textarea when typing, because that breaks IME).
+    poll: function() {
+      var cm = this.cm, input = this.textarea, prevInput = this.prevInput;
+      // Since this is called a *lot*, try to bail out as cheaply as
+      // possible when it is clear that nothing happened. hasSelection
+      // will be the case when there is a lot of text in the textarea,
+      // in which case reading its value would be expensive.
+      if (this.contextMenuPending || !cm.state.focused ||
+          (hasSelection(input) && !prevInput) ||
+          isReadOnly(cm) || cm.options.disableInput || cm.state.keySeq)
+        return false;
+
+      // See paste handler for more on the fakedLastChar kludge
+      if (cm.state.pasteIncoming && cm.state.fakedLastChar) {
+        input.value = input.value.substring(0, input.value.length - 1);
+        cm.state.fakedLastChar = false;
+      }
+      var text = input.value;
+      // If nothing changed, bail.
+      if (text == prevInput && !cm.somethingSelected()) return false;
+      // Work around nonsensical selection resetting in IE9/10, and
+      // inexplicable appearance of private area unicode characters on
+      // some key combos in Mac (#2689).
+      if (ie && ie_version >= 9 && this.hasSelection === text ||
+          mac && /[\uf700-\uf7ff]/.test(text)) {
+        cm.display.input.reset();
+        return false;
+      }
+
+      if (cm.doc.sel == cm.display.selForContextMenu) {
+        var first = text.charCodeAt(0);
+        if (first == 0x200b && !prevInput) prevInput = "\u200b";
+        if (first == 0x21da) { this.reset(); return this.cm.execCommand("undo"); }
+      }
+      // Find the part of the input that is actually new
+      var same = 0, l = Math.min(prevInput.length, text.length);
+      while (same < l && prevInput.charCodeAt(same) == text.charCodeAt(same)) ++same;
+
+      var self = this;
+      runInOp(cm, function() {
+        applyTextInput(cm, text.slice(same), prevInput.length - same,
+                       null, self.composing ? "*compose" : null);
+
+        // Don't leave long text in the textarea, since it makes further polling slow
+        if (text.length > 1000 || text.indexOf("\n") > -1) input.value = self.prevInput = "";
+        else self.prevInput = text;
+
+        if (self.composing) {
+          self.composing.range.clear();
+          self.composing.range = cm.markText(self.composing.start, cm.getCursor("to"),
+                                             {className: "CodeMirror-composing"});
+        }
+      });
+      return true;
+    },
+
+    ensurePolled: function() {
+      if (this.pollingFast && this.poll()) this.pollingFast = false;
+    },
+
+    onKeyPress: function() {
+      if (ie && ie_version >= 9) this.hasSelection = null;
+      this.fastPoll();
+    },
+
+    onContextMenu: function(e) {
+      var input = this, cm = input.cm, display = cm.display, te = input.textarea;
+      var pos = posFromMouse(cm, e), scrollPos = display.scroller.scrollTop;
+      if (!pos || presto) return; // Opera is difficult.
+
+      // Reset the current text selection only if the click is done outside of the selection
+      // and 'resetSelectionOnContextMenu' option is true.
+      var reset = cm.options.resetSelectionOnContextMenu;
+      if (reset && cm.doc.sel.contains(pos) == -1)
+        operation(cm, setSelection)(cm.doc, simpleSelection(pos), sel_dontScroll);
+
+      var oldCSS = te.style.cssText;
+      input.wrapper.style.position = "absolute";
+      te.style.cssText = "position: fixed; width: 30px; height: 30px; top: " + (e.clientY - 5) +
+        "px; left: " + (e.clientX - 5) + "px; z-index: 1000; background: " +
+        (ie ? "rgba(255, 255, 255, .05)" : "transparent") +
+        "; outline: none; border-width: 0; outline: none; overflow: hidden; opacity: .05; filter: alpha(opacity=5);";
+      if (webkit) var oldScrollY = window.scrollY; // Work around Chrome issue (#2712)
+      display.input.focus();
+      if (webkit) window.scrollTo(null, oldScrollY);
+      display.input.reset();
+      // Adds "Select all" to context menu in FF
+      if (!cm.somethingSelected()) te.value = input.prevInput = " ";
+      input.contextMenuPending = true;
+      display.selForContextMenu = cm.doc.sel;
+      clearTimeout(display.detectingSelectAll);
+
+      // Select-all will be greyed out if there's nothing to select, so
+      // this adds a zero-width space so that we can later check whether
+      // it got selected.
+      function prepareSelectAllHack() {
+        if (te.selectionStart != null) {
+          var selected = cm.somethingSelected();
+          var extval = "\u200b" + (selected ? te.value : "");
+          te.value = "\u21da"; // Used to catch context-menu undo
+          te.value = extval;
+          input.prevInput = selected ? "" : "\u200b";
+          te.selectionStart = 1; te.selectionEnd = extval.length;
+          // Re-set this, in case some other handler touched the
+          // selection in the meantime.
+          display.selForContextMenu = cm.doc.sel;
+        }
+      }
+      function rehide() {
+        input.contextMenuPending = false;
+        input.wrapper.style.position = "relative";
+        te.style.cssText = oldCSS;
+        if (ie && ie_version < 9) display.scrollbars.setScrollTop(display.scroller.scrollTop = scrollPos);
+
+        // Try to detect the user choosing select-all
+        if (te.selectionStart != null) {
+          if (!ie || (ie && ie_version < 9)) prepareSelectAllHack();
+          var i = 0, poll = function() {
+            if (display.selForContextMenu == cm.doc.sel && te.selectionStart == 0 &&
+                te.selectionEnd > 0 && input.prevInput == "\u200b")
+              operation(cm, commands.selectAll)(cm);
+            else if (i++ < 10) display.detectingSelectAll = setTimeout(poll, 500);
+            else display.input.reset();
+          };
+          display.detectingSelectAll = setTimeout(poll, 200);
+        }
+      }
+
+      if (ie && ie_version >= 9) prepareSelectAllHack();
+      if (captureRightClick) {
+        e_stop(e);
+        var mouseup = function() {
+          off(window, "mouseup", mouseup);
+          setTimeout(rehide, 20);
+        };
+        on(window, "mouseup", mouseup);
+      } else {
+        setTimeout(rehide, 50);
+      }
+    },
+
+    setUneditable: nothing,
+
+    needsContentAttribute: false
+  }, TextareaInput.prototype);
+
+  // CONTENTEDITABLE INPUT STYLE
+
+  function ContentEditableInput(cm) {
+    this.cm = cm;
+    this.lastAnchorNode = this.lastAnchorOffset = this.lastFocusNode = this.lastFocusOffset = null;
+    this.polling = new Delayed();
+    this.gracePeriod = false;
+  }
+
+  ContentEditableInput.prototype = copyObj({
+    init: function(display) {
+      var input = this, cm = input.cm;
+      var div = input.div = display.lineDiv;
+      div.contentEditable = "true";
+      disableBrowserMagic(div);
+
+      on(div, "paste", function(e) {
+        var pasted = e.clipboardData && e.clipboardData.getData("text/plain");
+        if (pasted) {
+          e.preventDefault();
+          cm.replaceSelection(pasted, null, "paste");
+        }
+      });
+
+      on(div, "compositionstart", function(e) {
+        var data = e.data;
+        input.composing = {sel: cm.doc.sel, data: data, startData: data};
+        if (!data) return;
+        var prim = cm.doc.sel.primary();
+        var line = cm.getLine(prim.head.line);
+        var found = line.indexOf(data, Math.max(0, prim.head.ch - data.length));
+        if (found > -1 && found <= prim.head.ch)
+          input.composing.sel = simpleSelection(Pos(prim.head.line, found),
+                                                Pos(prim.head.line, found + data.length));
+      });
+      on(div, "compositionupdate", function(e) {
+        input.composing.data = e.data;
+      });
+      on(div, "compositionend", function(e) {
+        var ours = input.composing;
+        if (!ours) return;
+        if (e.data != ours.startData && !/\u200b/.test(e.data))
+          ours.data = e.data;
+        // Need a small delay to prevent other code (input event,
+        // selection polling) from doing damage when fired right after
+        // compositionend.
+        setTimeout(function() {
+          if (!ours.handled)
+            input.applyComposition(ours);
+          if (input.composing == ours)
+            input.composing = null;
+        }, 50);
+      });
+
+      on(div, "touchstart", function() {
+        input.forceCompositionEnd();
+      });
+
+      on(div, "input", function() {
+        if (input.composing) return;
+        if (!input.pollContent())
+          runInOp(input.cm, function() {regChange(cm);});
+      });
+
+      function onCopyCut(e) {
+        if (cm.somethingSelected()) {
+          lastCopied = cm.getSelections();
+          if (e.type == "cut") cm.replaceSelection("", null, "cut");
+        } else if (!cm.options.lineWiseCopyCut) {
+          return;
+        } else {
+          var ranges = copyableRanges(cm);
+          lastCopied = ranges.text;
+          if (e.type == "cut") {
+            cm.operation(function() {
+              cm.setSelections(ranges.ranges, 0, sel_dontScroll);
+              cm.replaceSelection("", null, "cut");
+            });
+          }
+        }
+        // iOS exposes the clipboard API, but seems to discard content inserted into it
+        if (e.clipboardData && !ios) {
+          e.preventDefault();
+          e.clipboardData.clearData();
+          e.clipboardData.setData("text/plain", lastCopied.join("\n"));
+        } else {
+          // Old-fashioned briefly-focus-a-textarea hack
+          var kludge = hiddenTextarea(), te = kludge.firstChild;
+          cm.display.lineSpace.insertBefore(kludge, cm.display.lineSpace.firstChild);
+          te.value = lastCopied.join("\n");
+          var hadFocus = document.activeElement;
+          selectInput(te);
+          setTimeout(function() {
+            cm.display.lineSpace.removeChild(kludge);
+            hadFocus.focus();
+          }, 50);
+        }
+      }
+      on(div, "copy", onCopyCut);
+      on(div, "cut", onCopyCut);
+    },
+
+    prepareSelection: function() {
+      var result = prepareSelection(this.cm, false);
+      result.focus = this.cm.state.focused;
+      return result;
+    },
+
+    showSelection: function(info) {
+      if (!info || !this.cm.display.view.length) return;
+      if (info.focus) this.showPrimarySelection();
+      this.showMultipleSelections(info);
+    },
+
+    showPrimarySelection: function() {
+      var sel = window.getSelection(), prim = this.cm.doc.sel.primary();
+      var curAnchor = domToPos(this.cm, sel.anchorNode, sel.anchorOffset);
+      var curFocus = domToPos(this.cm, sel.focusNode, sel.focusOffset);
+      if (curAnchor && !curAnchor.bad && curFocus && !curFocus.bad &&
+          cmp(minPos(curAnchor, curFocus), prim.from()) == 0 &&
+          cmp(maxPos(curAnchor, curFocus), prim.to()) == 0)
+        return;
+
+      var start = posToDOM(this.cm, prim.from());
+      var end = posToDOM(this.cm, prim.to());
+      if (!start && !end) return;
+
+      var view = this.cm.display.view;
+      var old = sel.rangeCount && sel.getRangeAt(0);
+      if (!start) {
+        start = {node: view[0].measure.map[2], offset: 0};
+      } else if (!end) { // FIXME dangerously hacky
+        var measure = view[view.length - 1].measure;
+        var map = measure.maps ? measure.maps[measure.maps.length - 1] : measure.map;
+        end = {node: map[map.length - 1], offset: map[map.length - 2] - map[map.length - 3]};
+      }
+
+      try { var rng = range(start.node, start.offset, end.offset, end.node); }
+      catch(e) {} // Our model of the DOM might be outdated, in which case the range we try to set can be impossible
+      if (rng) {
+        sel.removeAllRanges();
+        sel.addRange(rng);
+        if (old && sel.anchorNode == null) sel.addRange(old);
+        else if (gecko) this.startGracePeriod();
+      }
+      this.rememberSelection();
+    },
+
+    startGracePeriod: function() {
+      var input = this;
+      clearTimeout(this.gracePeriod);
+      this.gracePeriod = setTimeout(function() {
+        input.gracePeriod = false;
+        if (input.selectionChanged())
+          input.cm.operation(function() { input.cm.curOp.selectionChanged = true; });
+      }, 20);
+    },
+
+    showMultipleSelections: function(info) {
+      removeChildrenAndAdd(this.cm.display.cursorDiv, info.cursors);
+      removeChildrenAndAdd(this.cm.display.selectionDiv, info.selection);
+    },
+
+    rememberSelection: function() {
+      var sel = window.getSelection();
+      this.lastAnchorNode = sel.anchorNode; this.lastAnchorOffset = sel.anchorOffset;
+      this.lastFocusNode = sel.focusNode; this.lastFocusOffset = sel.focusOffset;
+    },
+
+    selectionInEditor: function() {
+      var sel = window.getSelection();
+      if (!sel.rangeCount) return false;
+      var node = sel.getRangeAt(0).commonAncestorContainer;
+      return contains(this.div, node);
+    },
+
+    focus: function() {
+      if (this.cm.options.readOnly != "nocursor") this.div.focus();
+    },
+    blur: function() { this.div.blur(); },
+    getField: function() { return this.div; },
+
+    supportsTouch: function() { return true; },
+
+    receivedFocus: function() {
+      var input = this;
+      if (this.selectionInEditor())
+        this.pollSelection();
+      else
+        runInOp(this.cm, function() { input.cm.curOp.selectionChanged = true; });
+
+      function poll() {
+        if (input.cm.state.focused) {
+          input.pollSelection();
+          input.polling.set(input.cm.options.pollInterval, poll);
+        }
+      }
+      this.polling.set(this.cm.options.pollInterval, poll);
+    },
+
+    selectionChanged: function() {
+      var sel = window.getSelection();
+      return sel.anchorNode != this.lastAnchorNode || sel.anchorOffset != this.lastAnchorOffset ||
+        sel.focusNode != this.lastFocusNode || sel.focusOffset != this.lastFocusOffset;
+    },
+
+    pollSelection: function() {
+      if (!this.composing && !this.gracePeriod && this.selectionChanged()) {
+        var sel = window.getSelection(), cm = this.cm;
+        this.rememberSelection();
+        var anchor = domToPos(cm, sel.anchorNode, sel.anchorOffset);
+        var head = domToPos(cm, sel.focusNode, sel.focusOffset);
+        if (anchor && head) runInOp(cm, function() {
+          setSelection(cm.doc, simpleSelection(anchor, head), sel_dontScroll);
+          if (anchor.bad || head.bad) cm.curOp.selectionChanged = true;
+        });
+      }
+    },
+
+    pollContent: function() {
+      var cm = this.cm, display = cm.display, sel = cm.doc.sel.primary();
+      var from = sel.from(), to = sel.to();
+      if (from.line < display.viewFrom || to.line > display.viewTo - 1) return false;
+
+      var fromIndex;
+      if (from.line == display.viewFrom || (fromIndex = findViewIndex(cm, from.line)) == 0) {
+        var fromLine = lineNo(display.view[0].line);
+        var fromNode = display.view[0].node;
+      } else {
+        var fromLine = lineNo(display.view[fromIndex].line);
+        var fromNode = display.view[fromIndex - 1].node.nextSibling;
+      }
+      var toIndex = findViewIndex(cm, to.line);
+      if (toIndex == display.view.length - 1) {
+        var toLine = display.viewTo - 1;
+        var toNode = display.view[toIndex].node;
+      } else {
+        var toLine = lineNo(display.view[toIndex + 1].line) - 1;
+        var toNode = display.view[toIndex + 1].node.previousSibling;
+      }
+
+      var newText = splitLines(domTextBetween(cm, fromNode, toNode, fromLine, toLine));
+      var oldText = getBetween(cm.doc, Pos(fromLine, 0), Pos(toLine, getLine(cm.doc, toLine).text.length));
+      while (newText.length > 1 && oldText.length > 1) {
+        if (lst(newText) == lst(oldText)) { newText.pop(); oldText.pop(); toLine--; }
+        else if (newText[0] == oldText[0]) { newText.shift(); oldText.shift(); fromLine++; }
+        else break;
+      }
+
+      var cutFront = 0, cutEnd = 0;
+      var newTop = newText[0], oldTop = oldText[0], maxCutFront = Math.min(newTop.length, oldTop.length);
+      while (cutFront < maxCutFront && newTop.charCodeAt(cutFront) == oldTop.charCodeAt(cutFront))
+        ++cutFront;
+      var newBot = lst(newText), oldBot = lst(oldText);
+      var maxCutEnd = Math.min(newBot.length - (newText.length == 1 ? cutFront : 0),
+                               oldBot.length - (oldText.length == 1 ? cutFront : 0));
+      while (cutEnd < maxCutEnd &&
+             newBot.charCodeAt(newBot.length - cutEnd - 1) == oldBot.charCodeAt(oldBot.length - cutEnd - 1))
+        ++cutEnd;
+
+      newText[newText.length - 1] = newBot.slice(0, newBot.length - cutEnd);
+      newText[0] = newText[0].slice(cutFront);
+
+      var chFrom = Pos(fromLine, cutFront);
+      var chTo = Pos(toLine, oldText.length ? lst(oldText).length - cutEnd : 0);
+      if (newText.length > 1 || newText[0] || cmp(chFrom, chTo)) {
+        replaceRange(cm.doc, newText, chFrom, chTo, "+input");
+        return true;
+      }
+    },
+
+    ensurePolled: function() {
+      this.forceCompositionEnd();
+    },
+    reset: function() {
+      this.forceCompositionEnd();
+    },
+    forceCompositionEnd: function() {
+      if (!this.composing || this.composing.handled) return;
+      this.applyComposition(this.composing);
+      this.composing.handled = true;
+      this.div.blur();
+      this.div.focus();
+    },
+    applyComposition: function(composing) {
+      if (composing.data && composing.data != composing.startData)
+        operation(this.cm, applyTextInput)(this.cm, composing.data, 0, composing.sel);
+    },
+
+    setUneditable: function(node) {
+      node.setAttribute("contenteditable", "false");
+    },
+
+    onKeyPress: function(e) {
+      e.preventDefault();
+      operation(this.cm, applyTextInput)(this.cm, String.fromCharCode(e.charCode == null ? e.keyCode : e.charCode), 0);
+    },
+
+    onContextMenu: nothing,
+    resetPosition: nothing,
+
+    needsContentAttribute: true
+  }, ContentEditableInput.prototype);
+
+  function posToDOM(cm, pos) {
+    var view = findViewForLine(cm, pos.line);
+    if (!view || view.hidden) return null;
+    var line = getLine(cm.doc, pos.line);
+    var info = mapFromLineView(view, line, pos.line);
+
+    var order = getOrder(line), side = "left";
+    if (order) {
+      var partPos = getBidiPartAt(order, pos.ch);
+      side = partPos % 2 ? "right" : "left";
+    }
+    var result = nodeAndOffsetInLineMap(info.map, pos.ch, side);
+    result.offset = result.collapse == "right" ? result.end : result.start;
+    return result;
+  }
+
+  function badPos(pos, bad) { if (bad) pos.bad = true; return pos; }
+
+  function domToPos(cm, node, offset) {
+    var lineNode;
+    if (node == cm.display.lineDiv) {
+      lineNode = cm.display.lineDiv.childNodes[offset];
+      if (!lineNode) return badPos(cm.clipPos(Pos(cm.display.viewTo - 1)), true);
+      node = null; offset = 0;
+    } else {
+      for (lineNode = node;; lineNode = lineNode.parentNode) {
+        if (!lineNode || lineNode == cm.display.lineDiv) return null;
+        if (lineNode.parentNode && lineNode.parentNode == cm.display.lineDiv) break;
+      }
+    }
+    for (var i = 0; i < cm.display.view.length; i++) {
+      var lineView = cm.display.view[i];
+      if (lineView.node == lineNode)
+        return locateNodeInLineView(lineView, node, offset);
+    }
+  }
+
+  function locateNodeInLineView(lineView, node, offset) {
+    var wrapper = lineView.text.firstChild, bad = false;
+    if (!node || !contains(wrapper, node)) return badPos(Pos(lineNo(lineView.line), 0), true);
+    if (node == wrapper) {
+      bad = true;
+      node = wrapper.childNodes[offset];
+      offset = 0;
+      if (!node) {
+        var line = lineView.rest ? lst(lineView.rest) : lineView.line;
+        return badPos(Pos(lineNo(line), line.text.length), bad);
+      }
+    }
+
+    var textNode = node.nodeType == 3 ? node : null, topNode = node;
+    if (!textNode && node.childNodes.length == 1 && node.firstChild.nodeType == 3) {
+      textNode = node.firstChild;
+      if (offset) offset = textNode.nodeValue.length;
+    }
+    while (topNode.parentNode != wrapper) topNode = topNode.parentNode;
+    var measure = lineView.measure, maps = measure.maps;
+
+    function find(textNode, topNode, offset) {
+      for (var i = -1; i < (maps ? maps.length : 0); i++) {
+        var map = i < 0 ? measure.map : maps[i];
+        for (var j = 0; j < map.length; j += 3) {
+          var curNode = map[j + 2];
+          if (curNode == textNode || curNode == topNode) {
+            var line = lineNo(i < 0 ? lineView.line : lineView.rest[i]);
+            var ch = map[j] + offset;
+            if (offset < 0 || curNode != textNode) ch = map[j + (offset ? 1 : 0)];
+            return Pos(line, ch);
+          }
+        }
+      }
+    }
+    var found = find(textNode, topNode, offset);
+    if (found) return badPos(found, bad);
+
+    // FIXME this is all really shaky. might handle the few cases it needs to handle, but likely to cause problems
+    for (var after = topNode.nextSibling, dist = textNode ? textNode.nodeValue.length - offset : 0; after; after = after.nextSibling) {
+      found = find(after, after.firstChild, 0);
+      if (found)
+        return badPos(Pos(found.line, found.ch - dist), bad);
+      else
+        dist += after.textContent.length;
+    }
+    for (var before = topNode.previousSibling, dist = offset; before; before = before.previousSibling) {
+      found = find(before, before.firstChild, -1);
+      if (found)
+        return badPos(Pos(found.line, found.ch + dist), bad);
+      else
+        dist += after.textContent.length;
+    }
+  }
+
+  function domTextBetween(cm, from, to, fromLine, toLine) {
+    var text = "", closing = false;
+    function recognizeMarker(id) { return function(marker) { return marker.id == id; }; }
+    function walk(node) {
+      if (node.nodeType == 1) {
+        var cmText = node.getAttribute("cm-text");
+        if (cmText != null) {
+          if (cmText == "") cmText = node.textContent.replace(/\u200b/g, "");
+          text += cmText;
+          return;
+        }
+        var markerID = node.getAttribute("cm-marker"), range;
+        if (markerID) {
+          var found = cm.findMarks(Pos(fromLine, 0), Pos(toLine + 1, 0), recognizeMarker(+markerID));
+          if (found.length && (range = found[0].find()))
+            text += getBetween(cm.doc, range.from, range.to).join("\n");
+          return;
+        }
+        if (node.getAttribute("contenteditable") == "false") return;
+        for (var i = 0; i < node.childNodes.length; i++)
+          walk(node.childNodes[i]);
+        if (/^(pre|div|p)$/i.test(node.nodeName))
+          closing = true;
+      } else if (node.nodeType == 3) {
+        var val = node.nodeValue;
+        if (!val) return;
+        if (closing) {
+          text += "\n";
+          closing = false;
+        }
+        text += val;
+      }
+    }
+    for (;;) {
+      walk(from);
+      if (from == to) break;
+      from = from.nextSibling;
+    }
+    return text;
+  }
+
+  CodeMirror.inputStyles = {"textarea": TextareaInput, "contenteditable": ContentEditableInput};
+
+  // SELECTION / CURSOR
+
+  // Selection objects are immutable. A new one is created every time
+  // the selection changes. A selection is one or more non-overlapping
+  // (and non-touching) ranges, sorted, and an integer that indicates
+  // which one is the primary selection (the one that's scrolled into
+  // view, that getCursor returns, etc).
+  function Selection(ranges, primIndex) {
+    this.ranges = ranges;
+    this.primIndex = primIndex;
+  }
+
+  Selection.prototype = {
+    primary: function() { return this.ranges[this.primIndex]; },
+    equals: function(other) {
+      if (other == this) return true;
+      if (other.primIndex != this.primIndex || other.ranges.length != this.ranges.length) return false;
+      for (var i = 0; i < this.ranges.length; i++) {
+        var here = this.ranges[i], there = other.ranges[i];
+        if (cmp(here.anchor, there.anchor) != 0 || cmp(here.head, there.head) != 0) return false;
+      }
+      return true;
+    },
+    deepCopy: function() {
+      for (var out = [], i = 0; i < this.ranges.length; i++)
+        out[i] = new Range(copyPos(this.ranges[i].anchor), copyPos(this.ranges[i].head));
+      return new Selection(out, this.primIndex);
+    },
+    somethingSelected: function() {
+      for (var i = 0; i < this.ranges.length; i++)
+        if (!this.ranges[i].empty()) return true;
+      return false;
+    },
+    contains: function(pos, end) {
+      if (!end) end = pos;
+      for (var i = 0; i < this.ranges.length; i++) {
+        var range = this.ranges[i];
+        if (cmp(end, range.from()) >= 0 && cmp(pos, range.to()) <= 0)
+          return i;
+      }
+      return -1;
+    }
+  };
+
+  function Range(anchor, head) {
+    this.anchor = anchor; this.head = head;
+  }
+
+  Range.prototype = {
+    from: function() { return minPos(this.anchor, this.head); },
+    to: function() { return maxPos(this.anchor, this.head); },
+    empty: function() {
+      return this.head.line == this.anchor.line && this.head.ch == this.anchor.ch;
+    }
+  };
+
+  // Take an unsorted, potentially overlapping set of ranges, and
+  // build a selection out of it. 'Consumes' ranges array (modifying
+  // it).
+  function normalizeSelection(ranges, primIndex) {
+    var prim = ranges[primIndex];
+    ranges.sort(function(a, b) { return cmp(a.from(), b.from()); });
+    primIndex = indexOf(ranges, prim);
+    for (var i = 1; i < ranges.length; i++) {
+      var cur = ranges[i], prev = ranges[i - 1];
+      if (cmp(prev.to(), cur.from()) >= 0) {
+        var from = minPos(prev.from(), cur.from()), to = maxPos(prev.to(), cur.to());
+        var inv = prev.empty() ? cur.from() == cur.head : prev.from() == prev.head;
+        if (i <= primIndex) --primIndex;
+        ranges.splice(--i, 2, new Range(inv ? to : from, inv ? from : to));
+      }
+    }
+    return new Selection(ranges, primIndex);
+  }
+
+  function simpleSelection(anchor, head) {
+    return new Selection([new Range(anchor, head || anchor)], 0);
+  }
+
+  // Most of the external API clips given positions to make sure they
+  // actually exist within the document.
+  function clipLine(doc, n) {return Math.max(doc.first, Math.min(n, doc.first + doc.size - 1));}
+  function clipPos(doc, pos) {
+    if (pos.line < doc.first) return Pos(doc.first, 0);
+    var last = doc.first + doc.size - 1;
+    if (pos.line > last) return Pos(last, getLine(doc, last).text.length);
+    return clipToLen(pos, getLine(doc, pos.line).text.length);
+  }
+  function clipToLen(pos, linelen) {
+    var ch = pos.ch;
+    if (ch == null || ch > linelen) return Pos(pos.line, linelen);
+    else if (ch < 0) return Pos(pos.line, 0);
+    else return pos;
+  }
+  function isLine(doc, l) {return l >= doc.first && l < doc.first + doc.size;}
+  function clipPosArray(doc, array) {
+    for (var out = [], i = 0; i < array.length; i++) out[i] = clipPos(doc, array[i]);
+    return out;
+  }
+
+  // SELECTION UPDATES
+
+  // The 'scroll' parameter given to many of these indicated whether
+  // the new cursor position should be scrolled into view after
+  // modifying the selection.
+
+  // If shift is held or the extend flag is set, extends a range to
+  // include a given position (and optionally a second position).
+  // Otherwise, simply returns the range between the given positions.
+  // Used for cursor motion and such.
+  function extendRange(doc, range, head, other) {
+    if (doc.cm && doc.cm.display.shift || doc.extend) {
+      var anchor = range.anchor;
+      if (other) {
+        var posBefore = cmp(head, anchor) < 0;
+        if (posBefore != (cmp(other, anchor) < 0)) {
+          anchor = head;
+          head = other;
+        } else if (posBefore != (cmp(head, other) < 0)) {
+          head = other;
+        }
+      }
+      return new Range(anchor, head);
+    } else {
+      return new Range(other || head, head);
+    }
+  }
+
+  // Extend the primary selection range, discard the rest.
+  function extendSelection(doc, head, other, options) {
+    setSelection(doc, new Selection([extendRange(doc, doc.sel.primary(), head, other)], 0), options);
+  }
+
+  // Extend all selections (pos is an array of selections with length
+  // equal the number of selections)
+  function extendSelections(doc, heads, options) {
+    for (var out = [], i = 0; i < doc.sel.ranges.length; i++)
+      out[i] = extendRange(doc, doc.sel.ranges[i], heads[i], null);
+    var newSel = normalizeSelection(out, doc.sel.primIndex);
+    setSelection(doc, newSel, options);
+  }
+
+  // Updates a single range in the selection.
+  function replaceOneSelection(doc, i, range, options) {
+    var ranges = doc.sel.ranges.slice(0);
+    ranges[i] = range;
+    setSelection(doc, normalizeSelection(ranges, doc.sel.primIndex), options);
+  }
+
+  // Reset the selection to a single range.
+  function setSimpleSelection(doc, anchor, head, options) {
+    setSelection(doc, simpleSelection(anchor, head), options);
+  }
+
+  // Give beforeSelectionChange handlers a change to influence a
+  // selection update.
+  function filterSelectionChange(doc, sel) {
+    var obj = {
+      ranges: sel.ranges,
+      update: function(ranges) {
+        this.ranges = [];
+        for (var i = 0; i < ranges.length; i++)
+          this.ranges[i] = new Range(clipPos(doc, ranges[i].anchor),
+                                     clipPos(doc, ranges[i].head));
+      }
+    };
+    signal(doc, "beforeSelectionChange", doc, obj);
+    if (doc.cm) signal(doc.cm, "beforeSelectionChange", doc.cm, obj);
+    if (obj.ranges != sel.ranges) return normalizeSelection(obj.ranges, obj.ranges.length - 1);
+    else return sel;
+  }
+
+  function setSelectionReplaceHistory(doc, sel, options) {
+    var done = doc.history.done, last = lst(done);
+    if (last && last.ranges) {
+      done[done.length - 1] = sel;
+      setSelectionNoUndo(doc, sel, options);
+    } else {
+      setSelection(doc, sel, options);
+    }
+  }
+
+  // Set a new selection.
+  function setSelection(doc, sel, options) {
+    setSelectionNoUndo(doc, sel, options);
+    addSelectionToHistory(doc, doc.sel, doc.cm ? doc.cm.curOp.id : NaN, options);
+  }
+
+  function setSelectionNoUndo(doc, sel, options) {
+    if (hasHandler(doc, "beforeSelectionChange") || doc.cm && hasHandler(doc.cm, "beforeSelectionChange"))
+      sel = filterSelectionChange(doc, sel);
+
+    var bias = options && options.bias ||
+      (cmp(sel.primary().head, doc.sel.primary().head) < 0 ? -1 : 1);
+    setSelectionInner(doc, skipAtomicInSelection(doc, sel, bias, true));
+
+    if (!(options && options.scroll === false) && doc.cm)
+      ensureCursorVisible(doc.cm);
+  }
+
+  function setSelectionInner(doc, sel) {
+    if (sel.equals(doc.sel)) return;
+
+    doc.sel = sel;
+
+    if (doc.cm) {
+      doc.cm.curOp.updateInput = doc.cm.curOp.selectionChanged = true;
+      signalCursorActivity(doc.cm);
+    }
+    signalLater(doc, "cursorActivity", doc);
+  }
+
+  // Verify that the selection does not partially select any atomic
+  // marked ranges.
+  function reCheckSelection(doc) {
+    setSelectionInner(doc, skipAtomicInSelection(doc, doc.sel, null, false), sel_dontScroll);
+  }
+
+  // Return a selection that does not partially select any atomic
+  // ranges.
+  function skipAtomicInSelection(doc, sel, bias, mayClear) {
+    var out;
+    for (var i = 0; i < sel.ranges.length; i++) {
+      var range = sel.ranges[i];
+      var newAnchor = skipAtomic(doc, range.anchor, bias, mayClear);
+      var newHead = skipAtomic(doc, range.head, bias, mayClear);
+      if (out || newAnchor != range.anchor || newHead != range.head) {
+        if (!out) out = sel.ranges.slice(0, i);
+        out[i] = new Range(newAnchor, newHead);
+      }
+    }
+    return out ? normalizeSelection(out, sel.primIndex) : sel;
+  }
+
+  // Ensure a given position is not inside an atomic range.
+  function skipAtomic(doc, pos, bias, mayClear) {
+    var flipped = false, curPos = pos;
+    var dir = bias || 1;
+    doc.cantEdit = false;
+    search: for (;;) {
+      var line = getLine(doc, curPos.line);
+      if (line.markedSpans) {
+        for (var i = 0; i < line.markedSpans.length; ++i) {
+          var sp = line.markedSpans[i], m = sp.marker;
+          if ((sp.from == null || (m.inclusiveLeft ? sp.from <= curPos.ch : sp.from < curPos.ch)) &&
+              (sp.to == null || (m.inclusiveRight ? sp.to >= curPos.ch : sp.to > curPos.ch))) {
+            if (mayClear) {
+              signal(m, "beforeCursorEnter");
+              if (m.explicitlyCleared) {
+                if (!line.markedSpans) break;
+                else {--i; continue;}
+              }
+            }
+            if (!m.atomic) continue;
+            var newPos = m.find(dir < 0 ? -1 : 1);
+            if (cmp(newPos, curPos) == 0) {
+              newPos.ch += dir;
+              if (newPos.ch < 0) {
+                if (newPos.line > doc.first) newPos = clipPos(doc, Pos(newPos.line - 1));
+                else newPos = null;
+              } else if (newPos.ch > line.text.length) {
+                if (newPos.line < doc.first + doc.size - 1) newPos = Pos(newPos.line + 1, 0);
+                else newPos = null;
+              }
+              if (!newPos) {
+                if (flipped) {
+                  // Driven in a corner -- no valid cursor position found at all
+                  // -- try again *with* clearing, if we didn't already
+                  if (!mayClear) return skipAtomic(doc, pos, bias, true);
+                  // Otherwise, turn off editing until further notice, and return the start of the doc
+                  doc.cantEdit = true;
+                  return Pos(doc.first, 0);
+                }
+                flipped = true; newPos = pos; dir = -dir;
+              }
+            }
+            curPos = newPos;
+            continue search;
+          }
+        }
+      }
+      return curPos;
+    }
+  }
+
+  // SELECTION DRAWING
+
+  function updateSelection(cm) {
+    cm.display.input.showSelection(cm.display.input.prepareSelection());
+  }
+
+  function prepareSelection(cm, primary) {
+    var doc = cm.doc, result = {};
+    var curFragment = result.cursors = document.createDocumentFragment();
+    var selFragment = result.selection = document.createDocumentFragment();
+
+    for (var i = 0; i < doc.sel.ranges.length; i++) {
+      if (primary === false && i == doc.sel.primIndex) continue;
+      var range = doc.sel.ranges[i];
+      var collapsed = range.empty();
+      if (collapsed || cm.options.showCursorWhenSelecting)
+        drawSelectionCursor(cm, range, curFragment);
+      if (!collapsed)
+        drawSelectionRange(cm, range, selFragment);
+    }
+    return result;
+  }
+
+  // Draws a cursor for the given range
+  function drawSelectionCursor(cm, range, output) {
+    var pos = cursorCoords(cm, range.head, "div", null, null, !cm.options.singleCursorHeightPerLine);
+
+    var cursor = output.appendChild(elt("div", "\u00a0", "CodeMirror-cursor"));
+    cursor.style.left = pos.left + "px";
+    cursor.style.top = pos.top + "px";
+    cursor.style.height = Math.max(0, pos.bottom - pos.top) * cm.options.cursorHeight + "px";
+
+    if (pos.other) {
+      // Secondary cursor, shown when on a 'jump' in bi-directional text
+      var otherCursor = output.appendChild(elt("div", "\u00a0", "CodeMirror-cursor CodeMirror-secondarycursor"));
+      otherCursor.style.display = "";
+      otherCursor.style.left = pos.other.left + "px";
+      otherCursor.style.top = pos.other.top + "px";
+      otherCursor.style.height = (pos.other.bottom - pos.other.top) * .85 + "px";
+    }
+  }
+
+  // Draws the given range as a highlighted selection
+  function drawSelectionRange(cm, range, output) {
+    var display = cm.display, doc = cm.doc;
+    var fragment = document.createDocumentFragment();
+    var padding = paddingH(cm.display), leftSide = padding.left;
+    var rightSide = Math.max(display.sizerWidth, displayWidth(cm) - display.sizer.offsetLeft) - padding.right;
+
+    function add(left, top, width, bottom) {
+      if (top < 0) top = 0;
+      top = Math.round(top);
+      bottom = Math.round(bottom);
+      fragment.appendChild(elt("div", null, "CodeMirror-selected", "position: absolute; left: " + left +
+                               "px; top: " + top + "px; width: " + (width == null ? rightSide - left : width) +
+                               "px; height: " + (bottom - top) + "px"));
+    }
+
+    function drawForLine(line, fromArg, toArg) {
+      var lineObj = getLine(doc, line);
+      var lineLen = lineObj.text.length;
+      var start, end;
+      function coords(ch, bias) {
+        return charCoords(cm, Pos(line, ch), "div", lineObj, bias);
+      }
+
+      iterateBidiSections(getOrder(lineObj), fromArg || 0, toArg == null ? lineLen : toArg, function(from, to, dir) {
+        var leftPos = coords(from, "left"), rightPos, left, right;
+        if (from == to) {
+          rightPos = leftPos;
+          left = right = leftPos.left;
+        } else {
+          rightPos = coords(to - 1, "right");
+          if (dir == "rtl") { var tmp = leftPos; leftPos = rightPos; rightPos = tmp; }
+          left = leftPos.left;
+          right = rightPos.right;
+        }
+        if (fromArg == null && from == 0) left = leftSide;
+        if (rightPos.top - leftPos.top > 3) { // Different lines, draw top part
+          add(left, leftPos.top, null, leftPos.bottom);
+          left = leftSide;
+          if (leftPos.bottom < rightPos.top) add(left, leftPos.bottom, null, rightPos.top);
+        }
+        if (toArg == null && to == lineLen) right = rightSide;
+        if (!start || leftPos.top < start.top || leftPos.top == start.top && leftPos.left < start.left)
+          start = leftPos;
+        if (!end || rightPos.bottom > end.bottom || rightPos.bottom == end.bottom && rightPos.right > end.right)
+          end = rightPos;
+        if (left < leftSide + 1) left = leftSide;
+        add(left, rightPos.top, right - left, rightPos.bottom);
+      });
+      return {start: start, end: end};
+    }
+
+    var sFrom = range.from(), sTo = range.to();
+    if (sFrom.line == sTo.line) {
+      drawForLine(sFrom.line, sFrom.ch, sTo.ch);
+    } else {
+      var fromLine = getLine(doc, sFrom.line), toLine = getLine(doc, sTo.line);
+      var singleVLine = visualLine(fromLine) == visualLine(toLine);
+      var leftEnd = drawForLine(sFrom.line, sFrom.ch, singleVLine ? fromLine.text.length + 1 : null).end;
+      var rightStart = drawForLine(sTo.line, singleVLine ? 0 : null, sTo.ch).start;
+      if (singleVLine) {
+        if (leftEnd.top < rightStart.top - 2) {
+          add(leftEnd.right, leftEnd.top, null, leftEnd.bottom);
+          add(leftSide, rightStart.top, rightStart.left, rightStart.bottom);
+        } else {
+          add(leftEnd.right, leftEnd.top, rightStart.left - leftEnd.right, leftEnd.bottom);
+        }
+      }
+      if (leftEnd.bottom < rightStart.top)
+        add(leftSide, leftEnd.bottom, null, rightStart.top);
+    }
+
+    output.appendChild(fragment);
+  }
+
+  // Cursor-blinking
+  function restartBlink(cm) {
+    if (!cm.state.focused) return;
+    var display = cm.display;
+    clearInterval(display.blinker);
+    var on = true;
+    display.cursorDiv.style.visibility = "";
+    if (cm.options.cursorBlinkRate > 0)
+      display.blinker = setInterval(function() {
+        display.cursorDiv.style.visibility = (on = !on) ? "" : "hidden";
+      }, cm.options.cursorBlinkRate);
+    else if (cm.options.cursorBlinkRate < 0)
+      display.cursorDiv.style.visibility = "hidden";
+  }
+
+  // HIGHLIGHT WORKER
+
+  function startWorker(cm, time) {
+    if (cm.doc.mode.startState && cm.doc.frontier < cm.display.viewTo)
+      cm.state.highlight.set(time, bind(highlightWorker, cm));
+  }
+
+  function highlightWorker(cm) {
+    var doc = cm.doc;
+    if (doc.frontier < doc.first) doc.frontier = doc.first;
+    if (doc.frontier >= cm.display.viewTo) return;
+    var end = +new Date + cm.options.workTime;
+    var state = copyState(doc.mode, getStateBefore(cm, doc.frontier));
+    var changedLines = [];
+
+    doc.iter(doc.frontier, Math.min(doc.first + doc.size, cm.display.viewTo + 500), function(line) {
+      if (doc.frontier >= cm.display.viewFrom) { // Visible
+        var oldStyles = line.styles;
+        var highlighted = highlightLine(cm, line, state, true);
+        line.styles = highlighted.styles;
+        var oldCls = line.styleClasses, newCls = highlighted.classes;
+        if (newCls) line.styleClasses = newCls;
+        else if (oldCls) line.styleClasses = null;
+        var ischange = !oldStyles || oldStyles.length != line.styles.length ||
+          oldCls != newCls && (!oldCls || !newCls || oldCls.bgClass != newCls.bgClass || oldCls.textClass != newCls.textClass);
+        for (var i = 0; !ischange && i < oldStyles.length; ++i) ischange = oldStyles[i] != line.styles[i];
+        if (ischange) changedLines.push(doc.frontier);
+        line.stateAfter = copyState(doc.mode, state);
+      } else {
+        processLine(cm, line.text, state);
+        line.stateAfter = doc.frontier % 5 == 0 ? copyState(doc.mode, state) : null;
+      }
+      ++doc.frontier;
+      if (+new Date > end) {
+        startWorker(cm, cm.options.workDelay);
+        return true;
+      }
+    });
+    if (changedLines.length) runInOp(cm, function() {
+      for (var i = 0; i < changedLines.length; i++)
+        regLineChange(cm, changedLines[i], "text");
+    });
+  }
+
+  // Finds the line to start with when starting a parse. Tries to
+  // find a line with a stateAfter, so that it can start with a
+  // valid state. If that fails, it returns the line with the
+  // smallest indentation, which tends to need the least context to
+  // parse correctly.
+  function findStartLine(cm, n, precise) {
+    var minindent, minline, doc = cm.doc;
+    var lim = precise ? -1 : n - (cm.doc.mode.innerMode ? 1000 : 100);
+    for (var search = n; search > lim; --search) {
+      if (search <= doc.first) return doc.first;
+      var line = getLine(doc, search - 1);
+      if (line.stateAfter && (!precise || search <= doc.frontier)) return search;
+      var indented = countColumn(line.text, null, cm.options.tabSize);
+      if (minline == null || minindent > indented) {
+        minline = search - 1;
+        minindent = indented;
+      }
+    }
+    return minline;
+  }
+
+  function getStateBefore(cm, n, precise) {
+    var doc = cm.doc, display = cm.display;
+    if (!doc.mode.startState) return true;
+    var pos = findStartLine(cm, n, precise), state = pos > doc.first && getLine(doc, pos-1).stateAfter;
+    if (!state) state = startState(doc.mode);
+    else state = copyState(doc.mode, state);
+    doc.iter(pos, n, function(line) {
+      processLine(cm, line.text, state);
+      var save = pos == n - 1 || pos % 5 == 0 || pos >= display.viewFrom && pos < display.viewTo;
+      line.stateAfter = save ? copyState(doc.mode, state) : null;
+      ++pos;
+    });
+    if (precise) doc.frontier = pos;
+    return state;
+  }
+
+  // POSITION MEASUREMENT
+
+  function paddingTop(display) {return display.lineSpace.offsetTop;}
+  function paddingVert(display) {return display.mover.offsetHeight - display.lineSpace.offsetHeight;}
+  function paddingH(display) {
+    if (display.cachedPaddingH) return display.cachedPaddingH;
+    var e = removeChildrenAndAdd(display.measure, elt("pre", "x"));
+    var style = window.getComputedStyle ? window.getComputedStyle(e) : e.currentStyle;
+    var data = {left: parseInt(style.paddingLeft), right: parseInt(style.paddingRight)};
+    if (!isNaN(data.left) && !isNaN(data.right)) display.cachedPaddingH = data;
+    return data;
+  }
+
+  function scrollGap(cm) { return scrollerGap - cm.display.nativeBarWidth; }
+  function displayWidth(cm) {
+    return cm.display.scroller.clientWidth - scrollGap(cm) - cm.display.barWidth;
+  }
+  function displayHeight(cm) {
+    return cm.display.scroller.clientHeight - scrollGap(cm) - cm.display.barHeight;
+  }
+
+  // Ensure the lineView.wrapping.heights array is populated. This is
+  // an array of bottom offsets for the lines that make up a drawn
+  // line. When lineWrapping is on, there might be more than one
+  // height.
+  function ensureLineHeights(cm, lineView, rect) {
+    var wrapping = cm.options.lineWrapping;
+    var curWidth = wrapping && displayWidth(cm);
+    if (!lineView.measure.heights || wrapping && lineView.measure.width != curWidth) {
+      var heights = lineView.measure.heights = [];
+      if (wrapping) {
+        lineView.measure.width = curWidth;
+        var rects = lineView.text.firstChild.getClientRects();
+        for (var i = 0; i < rects.length - 1; i++) {
+          var cur = rects[i], next = rects[i + 1];
+          if (Math.abs(cur.bottom - next.bottom) > 2)
+            heights.push((cur.bottom + next.top) / 2 - rect.top);
+        }
+      }
+      heights.push(rect.bottom - rect.top);
+    }
+  }
+
+  // Find a line map (mapping character offsets to text nodes) and a
+  // measurement cache for the given line number. (A line view might
+  // contain multiple lines when collapsed ranges are present.)
+  function mapFromLineView(lineView, line, lineN) {
+    if (lineView.line == line)
+      return {map: lineView.measure.map, cache: lineView.measure.cache};
+    for (var i = 0; i < lineView.rest.length; i++)
+      if (lineView.rest[i] == line)
+        return {map: lineView.measure.maps[i], cache: lineView.measure.caches[i]};
+    for (var i = 0; i < lineView.rest.length; i++)
+      if (lineNo(lineView.rest[i]) > lineN)
+        return {map: lineView.measure.maps[i], cache: lineView.measure.caches[i], before: true};
+  }
+
+  // Render a line into the hidden node display.externalMeasured. Used
+  // when measurement is needed for a line that's not in the viewport.
+  function updateExternalMeasurement(cm, line) {
+    line = visualLine(line);
+    var lineN = lineNo(line);
+    var view = cm.display.externalMeasured = new LineView(cm.doc, line, lineN);
+    view.lineN = lineN;
+    var built = view.built = buildLineContent(cm, view);
+    view.text = built.pre;
+    removeChildrenAndAdd(cm.display.lineMeasure, built.pre);
+    return view;
+  }
+
+  // Get a {top, bottom, left, right} box (in line-local coordinates)
+  // for a given character.
+  function measureChar(cm, line, ch, bias) {
+    return measureCharPrepared(cm, prepareMeasureForLine(cm, line), ch, bias);
+  }
+
+  // Find a line view that corresponds to the given line number.
+  function findViewForLine(cm, lineN) {
+    if (lineN >= cm.display.viewFrom && lineN < cm.display.viewTo)
+      return cm.display.view[findViewIndex(cm, lineN)];
+    var ext = cm.display.externalMeasured;
+    if (ext && lineN >= ext.lineN && lineN < ext.lineN + ext.size)
+      return ext;
+  }
+
+  // Measurement can be split in two steps, the set-up work that
+  // applies to the whole line, and the measurement of the actual
+  // character. Functions like coordsChar, that need to do a lot of
+  // measurements in a row, can thus ensure that the set-up work is
+  // only done once.
+  function prepareMeasureForLine(cm, line) {
+    var lineN = lineNo(line);
+    var view = findViewForLine(cm, lineN);
+    if (view && !view.text)
+      view = null;
+    else if (view && view.changes)
+      updateLineForChanges(cm, view, lineN, getDimensions(cm));
+    if (!view)
+      view = updateExternalMeasurement(cm, line);
+
+    var info = mapFromLineView(view, line, lineN);
+    return {
+      line: line, view: view, rect: null,
+      map: info.map, cache: info.cache, before: info.before,
+      hasHeights: false
+    };
+  }
+
+  // Given a prepared measurement object, measures the position of an
+  // actual character (or fetches it from the cache).
+  function measureCharPrepared(cm, prepared, ch, bias, varHeight) {
+    if (prepared.before) ch = -1;
+    var key = ch + (bias || ""), found;
+    if (prepared.cache.hasOwnProperty(key)) {
+      found = prepared.cache[key];
+    } else {
+      if (!prepared.rect)
+        prepared.rect = prepared.view.text.getBoundingClientRect();
+      if (!prepared.hasHeights) {
+        ensureLineHeights(cm, prepared.view, prepared.rect);
+        prepared.hasHeights = true;
+      }
+      found = measureCharInner(cm, prepared, ch, bias);
+      if (!found.bogus) prepared.cache[key] = found;
+    }
+    return {left: found.left, right: found.right,
+            top: varHeight ? found.rtop : found.top,
+            bottom: varHeight ? found.rbottom : found.bottom};
+  }
+
+  var nullRect = {left: 0, right: 0, top: 0, bottom: 0};
+
+  function nodeAndOffsetInLineMap(map, ch, bias) {
+    var node, start, end, collapse;
+    // First, search the line map for the text node corresponding to,
+    // or closest to, the target character.
+    for (var i = 0; i < map.length; i += 3) {
+      var mStart = map[i], mEnd = map[i + 1];
+      if (ch < mStart) {
+        start = 0; end = 1;
+        collapse = "left";
+      } else if (ch < mEnd) {
+        start = ch - mStart;
+        end = start + 1;
+      } else if (i == map.length - 3 || ch == mEnd && map[i + 3] > ch) {
+        end = mEnd - mStart;
+        start = end - 1;
+        if (ch >= mEnd) collapse = "right";
+      }
+      if (start != null) {
+        node = map[i + 2];
+        if (mStart == mEnd && bias == (node.insertLeft ? "left" : "right"))
+          collapse = bias;
+        if (bias == "left" && start == 0)
+          while (i && map[i - 2] == map[i - 3] && map[i - 1].insertLeft) {
+            node = map[(i -= 3) + 2];
+            collapse = "left";
+          }
+        if (bias == "right" && start == mEnd - mStart)
+          while (i < map.length - 3 && map[i + 3] == map[i + 4] && !map[i + 5].insertLeft) {
+            node = map[(i += 3) + 2];
+            collapse = "right";
+          }
+        break;
+      }
+    }
+    return {node: node, start: start, end: end, collapse: collapse, coverStart: mStart, coverEnd: mEnd};
+  }
+
+  function measureCharInner(cm, prepared, ch, bias) {
+    var place = nodeAndOffsetInLineMap(prepared.map, ch, bias);
+    var node = place.node, start = place.start, end = place.end, collapse = place.collapse;
+
+    var rect;
+    if (node.nodeType == 3) { // If it is a text node, use a range to retrieve the coordinates.
+      for (var i = 0; i < 4; i++) { // Retry a maximum of 4 times when nonsense rectangles are returned
+        while (start && isExtendingChar(prepared.line.text.charAt(place.coverStart + start))) --start;
+        while (place.coverStart + end < place.coverEnd && isExtendingChar(prepared.line.text.charAt(place.coverStart + end))) ++end;
+        if (ie && ie_version < 9 && start == 0 && end == place.coverEnd - place.coverStart) {
+          rect = node.parentNode.getBoundingClientRect();
+        } else if (ie && cm.options.lineWrapping) {
+          var rects = range(node, start, end).getClientRects();
+          if (rects.length)
+            rect = rects[bias == "right" ? rects.length - 1 : 0];
+          else
+            rect = nullRect;
+        } else {
+          rect = range(node, start, end).getBoundingClientRect() || nullRect;
+        }
+        if (rect.left || rect.right || start == 0) break;
+        end = start;
+        start = start - 1;
+        collapse = "right";
+      }
+      if (ie && ie_version < 11) rect = maybeUpdateRectForZooming(cm.display.measure, rect);
+    } else { // If it is a widget, simply get the box for the whole widget.
+      if (start > 0) collapse = bias = "right";
+      var rects;
+      if (cm.options.lineWrapping && (rects = node.getClientRects()).length > 1)
+        rect = rects[bias == "right" ? rects.length - 1 : 0];
+      else
+        rect = node.getBoundingClientRect();
+    }
+    if (ie && ie_version < 9 && !start && (!rect || !rect.left && !rect.right)) {
+      var rSpan = node.parentNode.getClientRects()[0];
+      if (rSpan)
+        rect = {left: rSpan.left, right: rSpan.left + charWidth(cm.display), top: rSpan.top, bottom: rSpan.bottom};
+      else
+        rect = nullRect;
+    }
+
+    var rtop = rect.top - prepared.rect.top, rbot = rect.bottom - prepared.rect.top;
+    var mid = (rtop + rbot) / 2;
+    var heights = prepared.view.measure.heights;
+    for (var i = 0; i < heights.length - 1; i++)
+      if (mid < heights[i]) break;
+    var top = i ? heights[i - 1] : 0, bot = heights[i];
+    var result = {left: (collapse == "right" ? rect.right : rect.left) - prepared.rect.left,
+                  right: (collapse == "left" ? rect.left : rect.right) - prepared.rect.left,
+                  top: top, bottom: bot};
+    if (!rect.left && !rect.right) result.bogus = true;
+    if (!cm.options.singleCursorHeightPerLine) { result.rtop = rtop; result.rbottom = rbot; }
+
+    return result;
+  }
+
+  // Work around problem with bounding client rects on ranges being
+  // returned incorrectly when zoomed on IE10 and below.
+  function maybeUpdateRectForZooming(measure, rect) {
+    if (!window.screen || screen.logicalXDPI == null ||
+        screen.logicalXDPI == screen.deviceXDPI || !hasBadZoomedRects(measure))
+      return rect;
+    var scaleX = screen.logicalXDPI / screen.deviceXDPI;
+    var scaleY = screen.logicalYDPI / screen.deviceYDPI;
+    return {left: rect.left * scaleX, right: rect.right * scaleX,
+            top: rect.top * scaleY, bottom: rect.bottom * scaleY};
+  }
+
+  function clearLineMeasurementCacheFor(lineView) {
+    if (lineView.measure) {
+      lineView.measure.cache = {};
+      lineView.measure.heights = null;
+      if (lineView.rest) for (var i = 0; i < lineView.rest.length; i++)
+        lineView.measure.caches[i] = {};
+    }
+  }
+
+  function clearLineMeasurementCache(cm) {
+    cm.display.externalMeasure = null;
+    removeChildren(cm.display.lineMeasure);
+    for (var i = 0; i < cm.display.view.length; i++)
+      clearLineMeasurementCacheFor(cm.display.view[i]);
+  }
+
+  function clearCaches(cm) {
+    clearLineMeasurementCache(cm);
+    cm.display.cachedCharWidth = cm.display.cachedTextHeight = cm.display.cachedPaddingH = null;
+    if (!cm.options.lineWrapping) cm.display.maxLineChanged = true;
+    cm.display.lineNumChars = null;
+  }
+
+  function pageScrollX() { return window.pageXOffset || (document.documentElement || document.body).scrollLeft; }
+  function pageScrollY() { return window.pageYOffset || (document.documentElement || document.body).scrollTop; }
+
+  // Converts a {top, bottom, left, right} box from line-local
+  // coordinates into another coordinate system. Context may be one of
+  // "line", "div" (display.lineDiv), "local"/null (editor), "window",
+  // or "page".
+  function intoCoordSystem(cm, lineObj, rect, context) {
+    if (lineObj.widgets) for (var i = 0; i < lineObj.widgets.length; ++i) if (lineObj.widgets[i].above) {
+      var size = widgetHeight(lineObj.widgets[i]);
+      rect.top += size; rect.bottom += size;
+    }
+    if (context == "line") return rect;
+    if (!context) context = "local";
+    var yOff = heightAtLine(lineObj);
+    if (context == "local") yOff += paddingTop(cm.display);
+    else yOff -= cm.display.viewOffset;
+    if (context == "page" || context == "window") {
+      var lOff = cm.display.lineSpace.getBoundingClientRect();
+      yOff += lOff.top + (context == "window" ? 0 : pageScrollY());
+      var xOff = lOff.left + (context == "window" ? 0 : pageScrollX());
+      rect.left += xOff; rect.right += xOff;
+    }
+    rect.top += yOff; rect.bottom += yOff;
+    return rect;
+  }
+
+  // Coverts a box from "div" coords to another coordinate system.
+  // Context may be "window", "page", "div", or "local"/null.
+  function fromCoordSystem(cm, coords, context) {
+    if (context == "div") return coords;
+    var left = coords.left, top = coords.top;
+    // First move into "page" coordinate system
+    if (context == "page") {
+      left -= pageScrollX();
+      top -= pageScrollY();
+    } else if (context == "local" || !context) {
+      var localBox = cm.display.sizer.getBoundingClientRect();
+      left += localBox.left;
+      top += localBox.top;
+    }
+
+    var lineSpaceBox = cm.display.lineSpace.getBoundingClientRect();
+    return {left: left - lineSpaceBox.left, top: top - lineSpaceBox.top};
+  }
+
+  function charCoords(cm, pos, context, lineObj, bias) {
+    if (!lineObj) lineObj = getLine(cm.doc, pos.line);
+    return intoCoordSystem(cm, lineObj, measureChar(cm, lineObj, pos.ch, bias), context);
+  }
+
+  // Returns a box for a given cursor position, which may have an
+  // 'other' property containing the position of the secondary cursor
+  // on a bidi boundary.
+  function cursorCoords(cm, pos, context, lineObj, preparedMeasure, varHeight) {
+    lineObj = lineObj || getLine(cm.doc, pos.line);
+    if (!preparedMeasure) preparedMeasure = prepareMeasureForLine(cm, lineObj);
+    function get(ch, right) {
+      var m = measureCharPrepared(cm, preparedMeasure, ch, right ? "right" : "left", varHeight);
+      if (right) m.left = m.right; else m.right = m.left;
+      return intoCoordSystem(cm, lineObj, m, context);
+    }
+    function getBidi(ch, partPos) {
+      var part = order[partPos], right = part.level % 2;
+      if (ch == bidiLeft(part) && partPos && part.level < order[partPos - 1].level) {
+        part = order[--partPos];
+        ch = bidiRight(part) - (part.level % 2 ? 0 : 1);
+        right = true;
+      } else if (ch == bidiRight(part) && partPos < order.length - 1 && part.level < order[partPos + 1].level) {
+        part = order[++partPos];
+        ch = bidiLeft(part) - part.level % 2;
+        right = false;
+      }
+      if (right && ch == part.to && ch > part.from) return get(ch - 1);
+      return get(ch, right);
+    }
+    var order = getOrder(lineObj), ch = pos.ch;
+    if (!order) return get(ch);
+    var partPos = getBidiPartAt(order, ch);
+    var val = getBidi(ch, partPos);
+    if (bidiOther != null) val.other = getBidi(ch, bidiOther);
+    return val;
+  }
+
+  // Used to cheaply estimate the coordinates for a position. Used for
+  // intermediate scroll updates.
+  function estimateCoords(cm, pos) {
+    var left = 0, pos = clipPos(cm.doc, pos);
+    if (!cm.options.lineWrapping) left = charWidth(cm.display) * pos.ch;
+    var lineObj = getLine(cm.doc, pos.line);
+    var top = heightAtLine(lineObj) + paddingTop(cm.display);
+    return {left: left, right: left, top: top, bottom: top + lineObj.height};
+  }
+
+  // Positions returned by coordsChar contain some extra information.
+  // xRel is the relative x position of the input coordinates compared
+  // to the found position (so xRel > 0 means the coordinates are to
+  // the right of the character position, for example). When outside
+  // is true, that means the coordinates lie outside the line's
+  // vertical range.
+  function PosWithInfo(line, ch, outside, xRel) {
+    var pos = Pos(line, ch);
+    pos.xRel = xRel;
+    if (outside) pos.outside = true;
+    return pos;
+  }
+
+  // Compute the character position closest to the given coordinates.
+  // Input must be lineSpace-local ("div" coordinate system).
+  function coordsChar(cm, x, y) {
+    var doc = cm.doc;
+    y += cm.display.viewOffset;
+    if (y < 0) return PosWithInfo(doc.first, 0, true, -1);
+    var lineN = lineAtHeight(doc, y), last = doc.first + doc.size - 1;
+    if (lineN > last)
+      return PosWithInfo(doc.first + doc.size - 1, getLine(doc, last).text.length, true, 1);
+    if (x < 0) x = 0;
+
+    var lineObj = getLine(doc, lineN);
+    for (;;) {
+      var found = coordsCharInner(cm, lineObj, lineN, x, y);
+      var merged = collapsedSpanAtEnd(lineObj);
+      var mergedPos = merged && merged.find(0, true);
+      if (merged && (found.ch > mergedPos.from.ch || found.ch == mergedPos.from.ch && found.xRel > 0))
+        lineN = lineNo(lineObj = mergedPos.to.line);
+      else
+        return found;
+    }
+  }
+
+  function coordsCharInner(cm, lineObj, lineNo, x, y) {
+    var innerOff = y - heightAtLine(lineObj);
+    var wrongLine = false, adjust = 2 * cm.display.wrapper.clientWidth;
+    var preparedMeasure = prepareMeasureForLine(cm, lineObj);
+
+    function getX(ch) {
+      var sp = cursorCoords(cm, Pos(lineNo, ch), "line", lineObj, preparedMeasure);
+      wrongLine = true;
+      if (innerOff > sp.bottom) return sp.left - adjust;
+      else if (innerOff < sp.top) return sp.left + adjust;
+      else wrongLine = false;
+      return sp.left;
+    }
+
+    var bidi = getOrder(lineObj), dist = lineObj.text.length;
+    var from = lineLeft(lineObj), to = lineRight(lineObj);
+    var fromX = getX(from), fromOutside = wrongLine, toX = getX(to), toOutside = wrongLine;
+
+    if (x > toX) return PosWithInfo(lineNo, to, toOutside, 1);
+    // Do a binary search between these bounds.
+    for (;;) {
+      if (bidi ? to == from || to == moveVisually(lineObj, from, 1) : to - from <= 1) {
+        var ch = x < fromX || x - fromX <= toX - x ? from : to;
+        var xDiff = x - (ch == from ? fromX : toX);
+        while (isExtendingChar(lineObj.text.charAt(ch))) ++ch;
+        var pos = PosWithInfo(lineNo, ch, ch == from ? fromOutside : toOutside,
+                              xDiff < -1 ? -1 : xDiff > 1 ? 1 : 0);
+        return pos;
+      }
+      var step = Math.ceil(dist / 2), middle = from + step;
+      if (bidi) {
+        middle = from;
+        for (var i = 0; i < step; ++i) middle = moveVisually(lineObj, middle, 1);
+      }
+      var middleX = getX(middle);
+      if (middleX > x) {to = middle; toX = middleX; if (toOutside = wrongLine) toX += 1000; dist = step;}
+      else {from = middle; fromX = middleX; fromOutside = wrongLine; dist -= step;}
+    }
+  }
+
+  var measureText;
+  // Compute the default text height.
+  function textHeight(display) {
+    if (display.cachedTextHeight != null) return display.cachedTextHeight;
+    if (measureText == null) {
+      measureText = elt("pre");
+      // Measure a bunch of lines, for browsers that compute
+      // fractional heights.
+      for (var i = 0; i < 49; ++i) {
+        measureText.appendChild(document.createTextNode("x"));
+        measureText.appendChild(elt("br"));
+      }
+      measureText.appendChild(document.createTextNode("x"));
+    }
+    removeChildrenAndAdd(display.measure, measureText);
+    var height = measureText.offsetHeight / 50;
+    if (height > 3) display.cachedTextHeight = height;
+    removeChildren(display.measure);
+    return height || 1;
+  }
+
+  // Compute the default character width.
+  function charWidth(display) {
+    if (display.cachedCharWidth != null) return display.cachedCharWidth;
+    var anchor = elt("span", "xxxxxxxxxx");
+    var pre = elt("pre", [anchor]);
+    removeChildrenAndAdd(display.measure, pre);
+    var rect = anchor.getBoundingClientRect(), width = (rect.right - rect.left) / 10;
+    if (width > 2) display.cachedCharWidth = width;
+    return width || 10;
+  }
+
+  // OPERATIONS
+
+  // Operations are used to wrap a series of changes to the editor
+  // state in such a way that each change won't have to update the
+  // cursor and display (which would be awkward, slow, and
+  // error-prone). Instead, display updates are batched and then all
+  // combined and executed at once.
+
+  var operationGroup = null;
+
+  var nextOpId = 0;
+  // Start a new operation.
+  function startOperation(cm) {
+    cm.curOp = {
+      cm: cm,
+      viewChanged: false,      // Flag that indicates that lines might need to be redrawn
+      startHeight: cm.doc.height, // Used to detect need to update scrollbar
+      forceUpdate: false,      // Used to force a redraw
+      updateInput: null,       // Whether to reset the input textarea
+      typing: false,           // Whether this reset should be careful to leave existing text (for compositing)
+      changeObjs: null,        // Accumulated changes, for firing change events
+      cursorActivityHandlers: null, // Set of handlers to fire cursorActivity on
+      cursorActivityCalled: 0, // Tracks which cursorActivity handlers have been called already
+      selectionChanged: false, // Whether the selection needs to be redrawn
+      updateMaxLine: false,    // Set when the widest line needs to be determined anew
+      scrollLeft: null, scrollTop: null, // Intermediate scroll position, not pushed to DOM yet
+      scrollToPos: null,       // Used to scroll to a specific position
+      focus: false,
+      id: ++nextOpId           // Unique ID
+    };
+    if (operationGroup) {
+      operationGroup.ops.push(cm.curOp);
+    } else {
+      cm.curOp.ownsGroup = operationGroup = {
+        ops: [cm.curOp],
+        delayedCallbacks: []
+      };
+    }
+  }
+
+  function fireCallbacksForOps(group) {
+    // Calls delayed callbacks and cursorActivity handlers until no
+    // new ones appear
+    var callbacks = group.delayedCallbacks, i = 0;
+    do {
+      for (; i < callbacks.length; i++)
+        callbacks[i]();
+      for (var j = 0; j < group.ops.length; j++) {
+        var op = group.ops[j];
+        if (op.cursorActivityHandlers)
+          while (op.cursorActivityCalled < op.cursorActivityHandlers.length)
+            op.cursorActivityHandlers[op.cursorActivityCalled++](op.cm);
+      }
+    } while (i < callbacks.length);
+  }
+
+  // Finish an operation, updating the display and signalling delayed events
+  function endOperation(cm) {
+    var op = cm.curOp, group = op.ownsGroup;
+    if (!group) return;
+
+    try { fireCallbacksForOps(group); }
+    finally {
+      operationGroup = null;
+      for (var i = 0; i < group.ops.length; i++)
+        group.ops[i].cm.curOp = null;
+      endOperations(group);
+    }
+  }
+
+  // The DOM updates done when an operation finishes are batched so
+  // that the minimum number of relayouts are required.
+  function endOperations(group) {
+    var ops = group.ops;
+    for (var i = 0; i < ops.length; i++) // Read DOM
+      endOperation_R1(ops[i]);
+    for (var i = 0; i < ops.length; i++) // Write DOM (maybe)
+      endOperation_W1(ops[i]);
+    for (var i = 0; i < ops.length; i++) // Read DOM
+      endOperation_R2(ops[i]);
+    for (var i = 0; i < ops.length; i++) // Write DOM (maybe)
+      endOperation_W2(ops[i]);
+    for (var i = 0; i < ops.length; i++) // Read DOM
+      endOperation_finish(ops[i]);
+  }
+
+  function endOperation_R1(op) {
+    var cm = op.cm, display = cm.display;
+    maybeClipScrollbars(cm);
+    if (op.updateMaxLine) findMaxLine(cm);
+
+    op.mustUpdate = op.viewChanged || op.forceUpdate || op.scrollTop != null ||
+      op.scrollToPos && (op.scrollToPos.from.line < display.viewFrom ||
+                         op.scrollToPos.to.line >= display.viewTo) ||
+      display.maxLineChanged && cm.options.lineWrapping;
+    op.update = op.mustUpdate &&
+      new DisplayUpdate(cm, op.mustUpdate && {top: op.scrollTop, ensure: op.scrollToPos}, op.forceUpdate);
+  }
+
+  function endOperation_W1(op) {
+    op.updatedDisplay = op.mustUpdate && updateDisplayIfNeeded(op.cm, op.update);
+  }
+
+  function endOperation_R2(op) {
+    var cm = op.cm, display = cm.display;
+    if (op.updatedDisplay) updateHeightsInViewport(cm);
+
+    op.barMeasure = measureForScrollbars(cm);
+
+    // If the max line changed since it was last measured, measure it,
+    // and ensure the document's width matches it.
+    // updateDisplay_W2 will use these properties to do the actual resizing
+    if (display.maxLineChanged && !cm.options.lineWrapping) {
+      op.adjustWidthTo = measureChar(cm, display.maxLine, display.maxLine.text.length).left + 3;
+      cm.display.sizerWidth = op.adjustWidthTo;
+      op.barMeasure.scrollWidth =
+        Math.max(display.scroller.clientWidth, display.sizer.offsetLeft + op.adjustWidthTo + scrollGap(cm) + cm.display.barWidth);
+      op.maxScrollLeft = Math.max(0, display.sizer.offsetLeft + op.adjustWidthTo - displayWidth(cm));
+    }
+
+    if (op.updatedDisplay || op.selectionChanged)
+      op.preparedSelection = display.input.prepareSelection();
+  }
+
+  function endOperation_W2(op) {
+    var cm = op.cm;
+
+    if (op.adjustWidthTo != null) {
+      cm.display.sizer.style.minWidth = op.adjustWidthTo + "px";
+      if (op.maxScrollLeft < cm.doc.scrollLeft)
+        setScrollLeft(cm, Math.min(cm.display.scroller.scrollLeft, op.maxScrollLeft), true);
+      cm.display.maxLineChanged = false;
+    }
+
+    if (op.preparedSelection)
+      cm.display.input.showSelection(op.preparedSelection);
+    if (op.updatedDisplay)
+      setDocumentHeight(cm, op.barMeasure);
+    if (op.updatedDisplay || op.startHeight != cm.doc.height)
+      updateScrollbars(cm, op.barMeasure);
+
+    if (op.selectionChanged) restartBlink(cm);
+
+    if (cm.state.focused && op.updateInput)
+      cm.display.input.reset(op.typing);
+    if (op.focus && op.focus == activeElt()) ensureFocus(op.cm);
+  }
+
+  function endOperation_finish(op) {
+    var cm = op.cm, display = cm.display, doc = cm.doc;
+
+    if (op.updatedDisplay) postUpdateDisplay(cm, op.update);
+
+    // Abort mouse wheel delta measurement, when scrolling explicitly
+    if (display.wheelStartX != null && (op.scrollTop != null || op.scrollLeft != null || op.scrollToPos))
+      display.wheelStartX = display.wheelStartY = null;
+
+    // Propagate the scroll position to the actual DOM scroller
+    if (op.scrollTop != null && (display.scroller.scrollTop != op.scrollTop || op.forceScroll)) {
+      doc.scrollTop = Math.max(0, Math.min(display.scroller.scrollHeight - display.scroller.clientHeight, op.scrollTop));
+      display.scrollbars.setScrollTop(doc.scrollTop);
+      display.scroller.scrollTop = doc.scrollTop;
+    }
+    if (op.scrollLeft != null && (display.scroller.scrollLeft != op.scrollLeft || op.forceScroll)) {
+      doc.scrollLeft = Math.max(0, Math.min(display.scroller.scrollWidth - displayWidth(cm), op.scrollLeft));
+      display.scrollbars.setScrollLeft(doc.scrollLeft);
+      display.scroller.scrollLeft = doc.scrollLeft;
+      alignHorizontally(cm);
+    }
+    // If we need to scroll a specific position into view, do so.
+    if (op.scrollToPos) {
+      var coords = scrollPosIntoView(cm, clipPos(doc, op.scrollToPos.from),
+                                     clipPos(doc, op.scrollToPos.to), op.scrollToPos.margin);
+      if (op.scrollToPos.isCursor && cm.state.focused) maybeScrollWindow(cm, coords);
+    }
+
+    // Fire events for markers that are hidden/unidden by editing or
+    // undoing
+    var hidden = op.maybeHiddenMarkers, unhidden = op.maybeUnhiddenMarkers;
+    if (hidden) for (var i = 0; i < hidden.length; ++i)
+      if (!hidden[i].lines.length) signal(hidden[i], "hide");
+    if (unhidden) for (var i = 0; i < unhidden.length; ++i)
+      if (unhidden[i].lines.length) signal(unhidden[i], "unhide");
+
+    if (display.wrapper.offsetHeight)
+      doc.scrollTop = cm.display.scroller.scrollTop;
+
+    // Fire change events, and delayed event handlers
+    if (op.changeObjs)
+      signal(cm, "changes", cm, op.changeObjs);
+    if (op.update)
+      op.update.finish();
+  }
+
+  // Run the given function in an operation
+  function runInOp(cm, f) {
+    if (cm.curOp) return f();
+    startOperation(cm);
+    try { return f(); }
+    finally { endOperation(cm); }
+  }
+  // Wraps a function in an operation. Returns the wrapped function.
+  function operation(cm, f) {
+    return function() {
+      if (cm.curOp) return f.apply(cm, arguments);
+      startOperation(cm);
+      try { return f.apply(cm, arguments); }
+      finally { endOperation(cm); }
+    };
+  }
+  // Used to add methods to editor and doc instances, wrapping them in
+  // operations.
+  function methodOp(f) {
+    return function() {
+      if (this.curOp) return f.apply(this, arguments);
+      startOperation(this);
+      try { return f.apply(this, arguments); }
+      finally { endOperation(this); }
+    };
+  }
+  function docMethodOp(f) {
+    return function() {
+      var cm = this.cm;
+      if (!cm || cm.curOp) return f.apply(this, arguments);
+      startOperation(cm);
+      try { return f.apply(this, arguments); }
+      finally { endOperation(cm); }
+    };
+  }
+
+  // VIEW TRACKING
+
+  // These objects are used to represent the visible (currently drawn)
+  // part of the document. A LineView may correspond to multiple
+  // logical lines, if those are connected by collapsed ranges.
+  function LineView(doc, line, lineN) {
+    // The starting line
+    this.line = line;
+    // Continuing lines, if any
+    this.rest = visualLineContinued(line);
+    // Number of logical lines in this visual line
+    this.size = this.rest ? lineNo(lst(this.rest)) - lineN + 1 : 1;
+    this.node = this.text = null;
+    this.hidden = lineIsHidden(doc, line);
+  }
+
+  // Create a range of LineView objects for the given lines.
+  function buildViewArray(cm, from, to) {
+    var array = [], nextPos;
+    for (var pos = from; pos < to; pos = nextPos) {
+      var view = new LineView(cm.doc, getLine(cm.doc, pos), pos);
+      nextPos = pos + view.size;
+      array.push(view);
+    }
+    return array;
+  }
+
+  // Updates the display.view data structure for a given change to the
+  // document. From and to are in pre-change coordinates. Lendiff is
+  // the amount of lines added or subtracted by the change. This is
+  // used for changes that span multiple lines, or change the way
+  // lines are divided into visual lines. regLineChange (below)
+  // registers single-line changes.
+  function regChange(cm, from, to, lendiff) {
+    if (from == null) from = cm.doc.first;
+    if (to == null) to = cm.doc.first + cm.doc.size;
+    if (!lendiff) lendiff = 0;
+
+    var display = cm.display;
+    if (lendiff && to < display.viewTo &&
+        (display.updateLineNumbers == null || display.updateLineNumbers > from))
+      display.updateLineNumbers = from;
+
+    cm.curOp.viewChanged = true;
+
+    if (from >= display.viewTo) { // Change after
+      if (sawCollapsedSpans && visualLineNo(cm.doc, from) < display.viewTo)
+        resetView(cm);
+    } else if (to <= display.viewFrom) { // Change before
+      if (sawCollapsedSpans && visualLineEndNo(cm.doc, to + lendiff) > display.viewFrom) {
+        resetView(cm);
+      } else {
+        display.viewFrom += lendiff;
+        display.viewTo += lendiff;
+      }
+    } else if (from <= display.viewFrom && to >= display.viewTo) { // Full overlap
+      resetView(cm);
+    } else if (from <= display.viewFrom) { // Top overlap
+      var cut = viewCuttingPoint(cm, to, to + lendiff, 1);
+      if (cut) {
+        display.view = display.view.slice(cut.index);
+        display.viewFrom = cut.lineN;
+        display.viewTo += lendiff;
+      } else {
+        resetView(cm);
+      }
+    } else if (to >= display.viewTo) { // Bottom overlap
+      var cut = viewCuttingPoint(cm, from, from, -1);
+      if (cut) {
+        display.view = display.view.slice(0, cut.index);
+        display.viewTo = cut.lineN;
+      } else {
+        resetView(cm);
+      }
+    } else { // Gap in the middle
+      var cutTop = viewCuttingPoint(cm, from, from, -1);
+      var cutBot = viewCuttingPoint(cm, to, to + lendiff, 1);
+      if (cutTop && cutBot) {
+        display.view = display.view.slice(0, cutTop.index)
+          .concat(buildViewArray(cm, cutTop.lineN, cutBot.lineN))
+          .concat(display.view.slice(cutBot.index));
+        display.viewTo += lendiff;
+      } else {
+        resetView(cm);
+      }
+    }
+
+    var ext = display.externalMeasured;
+    if (ext) {
+      if (to < ext.lineN)
+        ext.lineN += lendiff;
+      else if (from < ext.lineN + ext.size)
+        display.externalMeasured = null;
+    }
+  }
+
+  // Register a change to a single line. Type must be one of "text",
+  // "gutter", "class", "widget"
+  function regLineChange(cm, line, type) {
+    cm.curOp.viewChanged = true;
+    var display = cm.display, ext = cm.display.externalMeasured;
+    if (ext && line >= ext.lineN && line < ext.lineN + ext.size)
+      display.externalMeasured = null;
+
+    if (line < display.viewFrom || line >= display.viewTo) return;
+    var lineView = display.view[findViewIndex(cm, line)];
+    if (lineView.node == null) return;
+    var arr = lineView.changes || (lineView.changes = []);
+    if (indexOf(arr, type) == -1) arr.push(type);
+  }
+
+  // Clear the view.
+  function resetView(cm) {
+    cm.display.viewFrom = cm.display.viewTo = cm.doc.first;
+    cm.display.view = [];
+    cm.display.viewOffset = 0;
+  }
+
+  // Find the view element corresponding to a given line. Return null
+  // when the line isn't visible.
+  function findViewIndex(cm, n) {
+    if (n >= cm.display.viewTo) return null;
+    n -= cm.display.viewFrom;
+    if (n < 0) return null;
+    var view = cm.display.view;
+    for (var i = 0; i < view.length; i++) {
+      n -= view[i].size;
+      if (n < 0) return i;
+    }
+  }
+
+  function viewCuttingPoint(cm, oldN, newN, dir) {
+    var index = findViewIndex(cm, oldN), diff, view = cm.display.view;
+    if (!sawCollapsedSpans || newN == cm.doc.first + cm.doc.size)
+      return {index: index, lineN: newN};
+    for (var i = 0, n = cm.display.viewFrom; i < index; i++)
+      n += view[i].size;
+    if (n != oldN) {
+      if (dir > 0) {
+        if (index == view.length - 1) return null;
+        diff = (n + view[index].size) - oldN;
+        index++;
+      } else {
+        diff = n - oldN;
+      }
+      oldN += diff; newN += diff;
+    }
+    while (visualLineNo(cm.doc, newN) != newN) {
+      if (index == (dir < 0 ? 0 : view.length - 1)) return null;
+      newN += dir * view[index - (dir < 0 ? 1 : 0)].size;
+      index += dir;
+    }
+    return {index: index, lineN: newN};
+  }
+
+  // Force the view to cover a given range, adding empty view element
+  // or clipping off existing ones as needed.
+  function adjustView(cm, from, to) {
+    var display = cm.display, view = display.view;
+    if (view.length == 0 || from >= display.viewTo || to <= display.viewFrom) {
+      display.view = buildViewArray(cm, from, to);
+      display.viewFrom = from;
+    } else {
+      if (display.viewFrom > from)
+        display.view = buildViewArray(cm, from, display.viewFrom).concat(display.view);
+      else if (display.viewFrom < from)
+        display.view = display.view.slice(findViewIndex(cm, from));
+      display.viewFrom = from;
+      if (display.viewTo < to)
+        display.view = display.view.concat(buildViewArray(cm, display.viewTo, to));
+      else if (display.viewTo > to)
+        display.view = display.view.slice(0, findViewIndex(cm, to));
+    }
+    display.viewTo = to;
+  }
+
+  // Count the number of lines in the view whose DOM representation is
+  // out of date (or nonexistent).
+  function countDirtyView(cm) {
+    var view = cm.display.view, dirty = 0;
+    for (var i = 0; i < view.length; i++) {
+      var lineView = view[i];
+      if (!lineView.hidden && (!lineView.node || lineView.changes)) ++dirty;
+    }
+    return dirty;
+  }
+
+  // EVENT HANDLERS
+
+  // Attach the necessary event handlers when initializing the editor
+  function registerEventHandlers(cm) {
+    var d = cm.display;
+    on(d.scroller, "mousedown", operation(cm, onMouseDown));
+    // Older IE's will not fire a second mousedown for a double click
+    if (ie && ie_version < 11)
+      on(d.scroller, "dblclick", operation(cm, function(e) {
+        if (signalDOMEvent(cm, e)) return;
+        var pos = posFromMouse(cm, e);
+        if (!pos || clickInGutter(cm, e) || eventInWidget(cm.display, e)) return;
+        e_preventDefault(e);
+        var word = cm.findWordAt(pos);
+        extendSelection(cm.doc, word.anchor, word.head);
+      }));
+    else
+      on(d.scroller, "dblclick", function(e) { signalDOMEvent(cm, e) || e_preventDefault(e); });
+    // Some browsers fire contextmenu *after* opening the menu, at
+    // which point we can't mess with it anymore. Context menu is
+    // handled in onMouseDown for these browsers.
+    if (!captureRightClick) on(d.scroller, "contextmenu", function(e) {onContextMenu(cm, e);});
+
+    // Used to suppress mouse event handling when a touch happens
+    var touchFinished, prevTouch = {end: 0};
+    function finishTouch() {
+      if (d.activeTouch) {
+        touchFinished = setTimeout(function() {d.activeTouch = null;}, 1000);
+        prevTouch = d.activeTouch;
+        prevTouch.end = +new Date;
+      }
+    };
+    function isMouseLikeTouchEvent(e) {
+      if (e.touches.length != 1) return false;
+      var touch = e.touches[0];
+      return touch.radiusX <= 1 && touch.radiusY <= 1;
+    }
+    function farAway(touch, other) {
+      if (other.left == null) return true;
+      var dx = other.left - touch.left, dy = other.top - touch.top;
+      return dx * dx + dy * dy > 20 * 20;
+    }
+    on(d.scroller, "touchstart", function(e) {
+      if (!isMouseLikeTouchEvent(e)) {
+        clearTimeout(touchFinished);
+        var now = +new Date;
+        d.activeTouch = {start: now, moved: false,
+                         prev: now - prevTouch.end <= 300 ? prevTouch : null};
+        if (e.touches.length == 1) {
+          d.activeTouch.left = e.touches[0].pageX;
+          d.activeTouch.top = e.touches[0].pageY;
+        }
+      }
+    });
+    on(d.scroller, "touchmove", function() {
+      if (d.activeTouch) d.activeTouch.moved = true;
+    });
+    on(d.scroller, "touchend", function(e) {
+      var touch = d.activeTouch;
+      if (touch && !eventInWidget(d, e) && touch.left != null &&
+          !touch.moved && new Date - touch.start < 300) {
+        var pos = cm.coordsChar(d.activeTouch, "page"), range;
+        if (!touch.prev || farAway(touch, touch.prev)) // Single tap
+          range = new Range(pos, pos);
+        else if (!touch.prev.prev || farAway(touch, touch.prev.prev)) // Double tap
+          range = cm.findWordAt(pos);
+        else // Triple tap
+          range = new Range(Pos(pos.line, 0), clipPos(cm.doc, Pos(pos.line + 1, 0)));
+        cm.setSelection(range.anchor, range.head);
+        cm.focus();
+        e_preventDefault(e);
+      }
+      finishTouch();
+    });
+    on(d.scroller, "touchcancel", finishTouch);
+
+    // Sync scrolling between fake scrollbars and real scrollable
+    // area, ensure viewport is updated when scrolling.
+    on(d.scroller, "scroll", function() {
+      if (d.scroller.clientHeight) {
+        setScrollTop(cm, d.scroller.scrollTop);
+        setScrollLeft(cm, d.scroller.scrollLeft, true);
+        signal(cm, "scroll", cm);
+      }
+    });
+
+    // Listen to wheel events in order to try and update the viewport on time.
+    on(d.scroller, "mousewheel", function(e){onScrollWheel(cm, e);});
+    on(d.scroller, "DOMMouseScroll", function(e){onScrollWheel(cm, e);});
+
+    // Prevent wrapper from ever scrolling
+    on(d.wrapper, "scroll", function() { d.wrapper.scrollTop = d.wrapper.scrollLeft = 0; });
+
+    d.dragFunctions = {
+      simple: function(e) {if (!signalDOMEvent(cm, e)) e_stop(e);},
+      start: function(e){onDragStart(cm, e);},
+      drop: operation(cm, onDrop)
+    };
+
+    var inp = d.input.getField();
+    on(inp, "keyup", function(e) { onKeyUp.call(cm, e); });
+    on(inp, "keydown", operation(cm, onKeyDown));
+    on(inp, "keypress", operation(cm, onKeyPress));
+    on(inp, "focus", bind(onFocus, cm));
+    on(inp, "blur", bind(onBlur, cm));
+  }
+
+  function dragDropChanged(cm, value, old) {
+    var wasOn = old && old != CodeMirror.Init;
+    if (!value != !wasOn) {
+      var funcs = cm.display.dragFunctions;
+      var toggle = value ? on : off;
+      toggle(cm.display.scroller, "dragstart", funcs.start);
+      toggle(cm.display.scroller, "dragenter", funcs.simple);
+      toggle(cm.display.scroller, "dragover", funcs.simple);
+      toggle(cm.display.scroller, "drop", funcs.drop);
+    }
+  }
+
+  // Called when the window resizes
+  function onResize(cm) {
+    var d = cm.display;
+    if (d.lastWrapHeight == d.wrapper.clientHeight && d.lastWrapWidth == d.wrapper.clientWidth)
+      return;
+    // Might be a text scaling operation, clear size caches.
+    d.cachedCharWidth = d.cachedTextHeight = d.cachedPaddingH = null;
+    d.scrollbarsClipped = false;
+    cm.setSize();
+  }
+
+  // MOUSE EVENTS
+
+  // Return true when the given mouse event happened in a widget
+  function eventInWidget(display, e) {
+    for (var n = e_target(e); n != display.wrapper; n = n.parentNode) {
+      if (!n || (n.nodeType == 1 && n.getAttribute("cm-ignore-events") == "true") ||
+          (n.parentNode == display.sizer && n != display.mover))
+        return true;
+    }
+  }
+
+  // Given a mouse event, find the corresponding position. If liberal
+  // is false, it checks whether a gutter or scrollbar was clicked,
+  // and returns null if it was. forRect is used by rectangular
+  // selections, and tries to estimate a character position even for
+  // coordinates beyond the right of the text.
+  function posFromMouse(cm, e, liberal, forRect) {
+    var display = cm.display;
+    if (!liberal && e_target(e).getAttribute("cm-not-content") == "true") return null;
+
+    var x, y, space = display.lineSpace.getBoundingClientRect();
+    // Fails unpredictably on IE[67] when mouse is dragged around quickly.
+    try { x = e.clientX - space.left; y = e.clientY - space.top; }
+    catch (e) { return null; }
+    var coords = coordsChar(cm, x, y), line;
+    if (forRect && coords.xRel == 1 && (line = getLine(cm.doc, coords.line).text).length == coords.ch) {
+      var colDiff = countColumn(line, line.length, cm.options.tabSize) - line.length;
+      coords = Pos(coords.line, Math.max(0, Math.round((x - paddingH(cm.display).left) / charWidth(cm.display)) - colDiff));
+    }
+    return coords;
+  }
+
+  // A mouse down can be a single click, double click, triple click,
+  // start of selection drag, start of text drag, new cursor
+  // (ctrl-click), rectangle drag (alt-drag), or xwin
+  // middle-click-paste. Or it might be a click on something we should
+  // not interfere with, such as a scrollbar or widget.
+  function onMouseDown(e) {
+    var cm = this, display = cm.display;
+    if (display.activeTouch && display.input.supportsTouch() || signalDOMEvent(cm, e)) return;
+    display.shift = e.shiftKey;
+
+    if (eventInWidget(display, e)) {
+      if (!webkit) {
+        // Briefly turn off draggability, to allow widgets to do
+        // normal dragging things.
+        display.scroller.draggable = false;
+        setTimeout(function(){display.scroller.draggable = true;}, 100);
+      }
+      return;
+    }
+    if (clickInGutter(cm, e)) return;
+    var start = posFromMouse(cm, e);
+    window.focus();
+
+    switch (e_button(e)) {
+    case 1:
+      if (start)
+        leftButtonDown(cm, e, start);
+      else if (e_target(e) == display.scroller)
+        e_preventDefault(e);
+      break;
+    case 2:
+      if (webkit) cm.state.lastMiddleDown = +new Date;
+      if (start) extendSelection(cm.doc, start);
+      setTimeout(function() {display.input.focus();}, 20);
+      e_preventDefault(e);
+      break;
+    case 3:
+      if (captureRightClick) onContextMenu(cm, e);
+      else delayBlurEvent(cm);
+      break;
+    }
+  }
+
+  var lastClick, lastDoubleClick;
+  function leftButtonDown(cm, e, start) {
+    if (ie) setTimeout(bind(ensureFocus, cm), 0);
+    else cm.curOp.focus = activeElt();
+
+    var now = +new Date, type;
+    if (lastDoubleClick && lastDoubleClick.time > now - 400 && cmp(lastDoubleClick.pos, start) == 0) {
+      type = "triple";
+    } else if (lastClick && lastClick.time > now - 400 && cmp(lastClick.pos, start) == 0) {
+      type = "double";
+      lastDoubleClick = {time: now, pos: start};
+    } else {
+      type = "single";
+      lastClick = {time: now, pos: start};
+    }
+
+    var sel = cm.doc.sel, modifier = mac ? e.metaKey : e.ctrlKey, contained;
+    if (cm.options.dragDrop && dragAndDrop && !isReadOnly(cm) &&
+        type == "single" && (contained = sel.contains(start)) > -1 &&
+        !sel.ranges[contained].empty())
+      leftButtonStartDrag(cm, e, start, modifier);
+    else
+      leftButtonSelect(cm, e, start, type, modifier);
+  }
+
+  // Start a text drag. When it ends, see if any dragging actually
+  // happen, and treat as a click if it didn't.
+  function leftButtonStartDrag(cm, e, start, modifier) {
+    var display = cm.display, startTime = +new Date;
+    var dragEnd = operation(cm, function(e2) {
+      if (webkit) display.scroller.draggable = false;
+      cm.state.draggingText = false;
+      off(document, "mouseup", dragEnd);
+      off(display.scroller, "drop", dragEnd);
+      if (Math.abs(e.clientX - e2.clientX) + Math.abs(e.clientY - e2.clientY) < 10) {
+        e_preventDefault(e2);
+        if (!modifier && +new Date - 200 < startTime)
+          extendSelection(cm.doc, start);
+        // Work around unexplainable focus problem in IE9 (#2127) and Chrome (#3081)
+        if (webkit || ie && ie_version == 9)
+          setTimeout(function() {document.body.focus(); display.input.focus();}, 20);
+        else
+          display.input.focus();
+      }
+    });
+    // Let the drag handler handle this.
+    if (webkit) display.scroller.draggable = true;
+    cm.state.draggingText = dragEnd;
+    // IE's approach to draggable
+    if (display.scroller.dragDrop) display.scroller.dragDrop();
+    on(document, "mouseup", dragEnd);
+    on(display.scroller, "drop", dragEnd);
+  }
+
+  // Normal selection, as opposed to text dragging.
+  function leftButtonSelect(cm, e, start, type, addNew) {
+    var display = cm.display, doc = cm.doc;
+    e_preventDefault(e);
+
+    var ourRange, ourIndex, startSel = doc.sel, ranges = startSel.ranges;
+    if (addNew && !e.shiftKey) {
+      ourIndex = doc.sel.contains(start);
+      if (ourIndex > -1)
+        ourRange = ranges[ourIndex];
+      else
+        ourRange = new Range(start, start);
+    } else {
+      ourRange = doc.sel.primary();
+      ourIndex = doc.sel.primIndex;
+    }
+
+    if (e.altKey) {
+      type = "rect";
+      if (!addNew) ourRange = new Range(start, start);
+      start = posFromMouse(cm, e, true, true);
+      ourIndex = -1;
+    } else if (type == "double") {
+      var word = cm.findWordAt(start);
+      if (cm.display.shift || doc.extend)
+        ourRange = extendRange(doc, ourRange, word.anchor, word.head);
+      else
+        ourRange = word;
+    } else if (type == "triple") {
+      var line = new Range(Pos(start.line, 0), clipPos(doc, Pos(start.line + 1, 0)));
+      if (cm.display.shift || doc.extend)
+        ourRange = extendRange(doc, ourRange, line.anchor, line.head);
+      else
+        ourRange = line;
+    } else {
+      ourRange = extendRange(doc, ourRange, start);
+    }
+
+    if (!addNew) {
+      ourIndex = 0;
+      setSelection(doc, new Selection([ourRange], 0), sel_mouse);
+      startSel = doc.sel;
+    } else if (ourIndex == -1) {
+      ourIndex = ranges.length;
+      setSelection(doc, normalizeSelection(ranges.concat([ourRange]), ourIndex),
+                   {scroll: false, origin: "*mouse"});
+    } else if (ranges.length > 1 && ranges[ourIndex].empty() && type == "single" && !e.shiftKey) {
+      setSelection(doc, normalizeSelection(ranges.slice(0, ourIndex).concat(ranges.slice(ourIndex + 1)), 0));
+      startSel = doc.sel;
+    } else {
+      replaceOneSelection(doc, ourIndex, ourRange, sel_mouse);
+    }
+
+    var lastPos = start;
+    function extendTo(pos) {
+      if (cmp(lastPos, pos) == 0) return;
+      lastPos = pos;
+
+      if (type == "rect") {
+        var ranges = [], tabSize = cm.options.tabSize;
+        var startCol = countColumn(getLine(doc, start.line).text, start.ch, tabSize);
+        var posCol = countColumn(getLine(doc, pos.line).text, pos.ch, tabSize);
+        var left = Math.min(startCol, posCol), right = Math.max(startCol, posCol);
+        for (var line = Math.min(start.line, pos.line), end = Math.min(cm.lastLine(), Math.max(start.line, pos.line));
+             line <= end; line++) {
+          var text = getLine(doc, line).text, leftPos = findColumn(text, left, tabSize);
+          if (left == right)
+            ranges.push(new Range(Pos(line, leftPos), Pos(line, leftPos)));
+          else if (text.length > leftPos)
+            ranges.push(new Range(Pos(line, leftPos), Pos(line, findColumn(text, right, tabSize))));
+        }
+        if (!ranges.length) ranges.push(new Range(start, start));
+        setSelection(doc, normalizeSelection(startSel.ranges.slice(0, ourIndex).concat(ranges), ourIndex),
+                     {origin: "*mouse", scroll: false});
+        cm.scrollIntoView(pos);
+      } else {
+        var oldRange = ourRange;
+        var anchor = oldRange.anchor, head = pos;
+        if (type != "single") {
+          if (type == "double")
+            var range = cm.findWordAt(pos);
+          else
+            var range = new Range(Pos(pos.line, 0), clipPos(doc, Pos(pos.line + 1, 0)));
+          if (cmp(range.anchor, anchor) > 0) {
+            head = range.head;
+            anchor = minPos(oldRange.from(), range.anchor);
+          } else {
+            head = range.anchor;
+            anchor = maxPos(oldRange.to(), range.head);
+          }
+        }
+        var ranges = startSel.ranges.slice(0);
+        ranges[ourIndex] = new Range(clipPos(doc, anchor), head);
+        setSelection(doc, normalizeSelection(ranges, ourIndex), sel_mouse);
+      }
+    }
+
+    var editorSize = display.wrapper.getBoundingClientRect();
+    // Used to ensure timeout re-tries don't fire when another extend
+    // happened in the meantime (clearTimeout isn't reliable -- at
+    // least on Chrome, the timeouts still happen even when cleared,
+    // if the clear happens after their scheduled firing time).
+    var counter = 0;
+
+    function extend(e) {
+      var curCount = ++counter;
+      var cur = posFromMouse(cm, e, true, type == "rect");
+      if (!cur) return;
+      if (cmp(cur, lastPos) != 0) {
+        cm.curOp.focus = activeElt();
+        extendTo(cur);
+        var visible = visibleLines(display, doc);
+        if (cur.line >= visible.to || cur.line < visible.from)
+          setTimeout(operation(cm, function(){if (counter == curCount) extend(e);}), 150);
+      } else {
+        var outside = e.clientY < editorSize.top ? -20 : e.clientY > editorSize.bottom ? 20 : 0;
+        if (outside) setTimeout(operation(cm, function() {
+          if (counter != curCount) return;
+          display.scroller.scrollTop += outside;
+          extend(e);
+        }), 50);
+      }
+    }
+
+    function done(e) {
+      counter = Infinity;
+      e_preventDefault(e);
+      display.input.focus();
+      off(document, "mousemove", move);
+      off(document, "mouseup", up);
+      doc.history.lastSelOrigin = null;
+    }
+
+    var move = operation(cm, function(e) {
+      if (!e_button(e)) done(e);
+      else extend(e);
+    });
+    var up = operation(cm, done);
+    on(document, "mousemove", move);
+    on(document, "mouseup", up);
+  }
+
+  // Determines whether an event happened in the gutter, and fires the
+  // handlers for the corresponding event.
+  function gutterEvent(cm, e, type, prevent, signalfn) {
+    try { var mX = e.clientX, mY = e.clientY; }
+    catch(e) { return false; }
+    if (mX >= Math.floor(cm.display.gutters.getBoundingClientRect().right)) return false;
+    if (prevent) e_preventDefault(e);
+
+    var display = cm.display;
+    var lineBox = display.lineDiv.getBoundingClientRect();
+
+    if (mY > lineBox.bottom || !hasHandler(cm, type)) return e_defaultPrevented(e);
+    mY -= lineBox.top - display.viewOffset;
+
+    for (var i = 0; i < cm.options.gutters.length; ++i) {
+      var g = display.gutters.childNodes[i];
+      if (g && g.getBoundingClientRect().right >= mX) {
+        var line = lineAtHeight(cm.doc, mY);
+        var gutter = cm.options.gutters[i];
+        signalfn(cm, type, cm, line, gutter, e);
+        return e_defaultPrevented(e);
+      }
+    }
+  }
+
+  function clickInGutter(cm, e) {
+    return gutterEvent(cm, e, "gutterClick", true, signalLater);
+  }
+
+  // Kludge to work around strange IE behavior where it'll sometimes
+  // re-fire a series of drag-related events right after the drop (#1551)
+  var lastDrop = 0;
+
+  function onDrop(e) {
+    var cm = this;
+    if (signalDOMEvent(cm, e) || eventInWidget(cm.display, e))
+      return;
+    e_preventDefault(e);
+    if (ie) lastDrop = +new Date;
+    var pos = posFromMouse(cm, e, true), files = e.dataTransfer.files;
+    if (!pos || isReadOnly(cm)) return;
+    // Might be a file drop, in which case we simply extract the text
+    // and insert it.
+    if (files && files.length && window.FileReader && window.File) {
+      var n = files.length, text = Array(n), read = 0;
+      var loadFile = function(file, i) {
+        var reader = new FileReader;
+        reader.onload = operation(cm, function() {
+          text[i] = reader.result;
+          if (++read == n) {
+            pos = clipPos(cm.doc, pos);
+            var change = {from: pos, to: pos, text: splitLines(text.join("\n")), origin: "paste"};
+            makeChange(cm.doc, change);
+            setSelectionReplaceHistory(cm.doc, simpleSelection(pos, changeEnd(change)));
+          }
+        });
+        reader.readAsText(file);
+      };
+      for (var i = 0; i < n; ++i) loadFile(files[i], i);
+    } else { // Normal drop
+      // Don't do a replace if the drop happened inside of the selected text.
+      if (cm.state.draggingText && cm.doc.sel.contains(pos) > -1) {
+        cm.state.draggingText(e);
+        // Ensure the editor is re-focused
+        setTimeout(function() {cm.display.input.focus();}, 20);
+        return;
+      }
+      try {
+        var text = e.dataTransfer.getData("Text");
+        if (text) {
+          if (cm.state.draggingText && !(mac ? e.altKey : e.ctrlKey))
+            var selected = cm.listSelections();
+          setSelectionNoUndo(cm.doc, simpleSelection(pos, pos));
+          if (selected) for (var i = 0; i < selected.length; ++i)
+            replaceRange(cm.doc, "", selected[i].anchor, selected[i].head, "drag");
+          cm.replaceSelection(text, "around", "paste");
+          cm.display.input.focus();
+        }
+      }
+      catch(e){}
+    }
+  }
+
+  function onDragStart(cm, e) {
+    if (ie && (!cm.state.draggingText || +new Date - lastDrop < 100)) { e_stop(e); return; }
+    if (signalDOMEvent(cm, e) || eventInWidget(cm.display, e)) return;
+
+    e.dataTransfer.setData("Text", cm.getSelection());
+
+    // Use dummy image instead of default browsers image.
+    // Recent Safari (~6.0.2) have a tendency to segfault when this happens, so we don't do it there.
+    if (e.dataTransfer.setDragImage && !safari) {
+      var img = elt("img", null, null, "position: fixed; left: 0; top: 0;");
+      img.src = "data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==";
+      if (presto) {
+        img.width = img.height = 1;
+        cm.display.wrapper.appendChild(img);
+        // Force a relayout, or Opera won't use our image for some obscure reason
+        img._top = img.offsetTop;
+      }
+      e.dataTransfer.setDragImage(img, 0, 0);
+      if (presto) img.parentNode.removeChild(img);
+    }
+  }
+
+  // SCROLL EVENTS
+
+  // Sync the scrollable area and scrollbars, ensure the viewport
+  // covers the visible area.
+  function setScrollTop(cm, val) {
+    if (Math.abs(cm.doc.scrollTop - val) < 2) return;
+    cm.doc.scrollTop = val;
+    if (!gecko) updateDisplaySimple(cm, {top: val});
+    if (cm.display.scroller.scrollTop != val) cm.display.scroller.scrollTop = val;
+    cm.display.scrollbars.setScrollTop(val);
+    if (gecko) updateDisplaySimple(cm);
+    startWorker(cm, 100);
+  }
+  // Sync scroller and scrollbar, ensure the gutter elements are
+  // aligned.
+  function setScrollLeft(cm, val, isScroller) {
+    if (isScroller ? val == cm.doc.scrollLeft : Math.abs(cm.doc.scrollLeft - val) < 2) return;
+    val = Math.min(val, cm.display.scroller.scrollWidth - cm.display.scroller.clientWidth);
+    cm.doc.scrollLeft = val;
+    alignHorizontally(cm);
+    if (cm.display.scroller.scrollLeft != val) cm.display.scroller.scrollLeft = val;
+    cm.display.scrollbars.setScrollLeft(val);
+  }
+
+  // Since the delta values reported on mouse wheel events are
+  // unstandardized between browsers and even browser versions, and
+  // generally horribly unpredictable, this code starts by measuring
+  // the scroll effect that the first few mouse wheel events have,
+  // and, from that, detects the way it can convert deltas to pixel
+  // offsets afterwards.
+  //
+  // The reason we want to know the amount a wheel event will scroll
+  // is that it gives us a chance to update the display before the
+  // actual scrolling happens, reducing flickering.
+
+  var wheelSamples = 0, wheelPixelsPerUnit = null;
+  // Fill in a browser-detected starting value on browsers where we
+  // know one. These don't have to be accurate -- the result of them
+  // being wrong would just be a slight flicker on the first wheel
+  // scroll (if it is large enough).
+  if (ie) wheelPixelsPerUnit = -.53;
+  else if (gecko) wheelPixelsPerUnit = 15;
+  else if (chrome) wheelPixelsPerUnit = -.7;
+  else if (safari) wheelPixelsPerUnit = -1/3;
+
+  var wheelEventDelta = function(e) {
+    var dx = e.wheelDeltaX, dy = e.wheelDeltaY;
+    if (dx == null && e.detail && e.axis == e.HORIZONTAL_AXIS) dx = e.detail;
+    if (dy == null && e.detail && e.axis == e.VERTICAL_AXIS) dy = e.detail;
+    else if (dy == null) dy = e.wheelDelta;
+    return {x: dx, y: dy};
+  };
+  CodeMirror.wheelEventPixels = function(e) {
+    var delta = wheelEventDelta(e);
+    delta.x *= wheelPixelsPerUnit;
+    delta.y *= wheelPixelsPerUnit;
+    return delta;
+  };
+
+  function onScrollWheel(cm, e) {
+    var delta = wheelEventDelta(e), dx = delta.x, dy = delta.y;
+
+    var display = cm.display, scroll = display.scroller;
+    // Quit if there's nothing to scroll here
+    if (!(dx && scroll.scrollWidth > scroll.clientWidth ||
+          dy && scroll.scrollHeight > scroll.clientHeight)) return;
+
+    // Webkit browsers on OS X abort momentum scrolls when the target
+    // of the scroll event is removed from the scrollable element.
+    // This hack (see related code in patchDisplay) makes sure the
+    // element is kept around.
+    if (dy && mac && webkit) {
+      outer: for (var cur = e.target, view = display.view; cur != scroll; cur = cur.parentNode) {
+        for (var i = 0; i < view.length; i++) {
+          if (view[i].node == cur) {
+            cm.display.currentWheelTarget = cur;
+            break outer;
+          }
+        }
+      }
+    }
+
+    // On some browsers, horizontal scrolling will cause redraws to
+    // happen before the gutter has been realigned, causing it to
+    // wriggle around in a most unseemly way. When we have an
+    // estimated pixels/delta value, we just handle horizontal
+    // scrolling entirely here. It'll be slightly off from native, but
+    // better than glitching out.
+    if (dx && !gecko && !presto && wheelPixelsPerUnit != null) {
+      if (dy)
+        setScrollTop(cm, Math.max(0, Math.min(scroll.scrollTop + dy * wheelPixelsPerUnit, scroll.scrollHeight - scroll.clientHeight)));
+      setScrollLeft(cm, Math.max(0, Math.min(scroll.scrollLeft + dx * wheelPixelsPerUnit, scroll.scrollWidth - scroll.clientWidth)));
+      e_preventDefault(e);
+      display.wheelStartX = null; // Abort measurement, if in progress
+      return;
+    }
+
+    // 'Project' the visible viewport to cover the area that is being
+    // scrolled into view (if we know enough to estimate it).
+    if (dy && wheelPixelsPerUnit != null) {
+      var pixels = dy * wheelPixelsPerUnit;
+      var top = cm.doc.scrollTop, bot = top + display.wrapper.clientHeight;
+      if (pixels < 0) top = Math.max(0, top + pixels - 50);
+      else bot = Math.min(cm.doc.height, bot + pixels + 50);
+      updateDisplaySimple(cm, {top: top, bottom: bot});
+    }
+
+    if (wheelSamples < 20) {
+      if (display.wheelStartX == null) {
+        display.wheelStartX = scroll.scrollLeft; display.wheelStartY = scroll.scrollTop;
+        display.wheelDX = dx; display.wheelDY = dy;
+        setTimeout(function() {
+          if (display.wheelStartX == null) return;
+          var movedX = scroll.scrollLeft - display.wheelStartX;
+          var movedY = scroll.scrollTop - display.wheelStartY;
+          var sample = (movedY && display.wheelDY && movedY / display.wheelDY) ||
+            (movedX && display.wheelDX && movedX / display.wheelDX);
+          display.wheelStartX = display.wheelStartY = null;
+          if (!sample) return;
+          wheelPixelsPerUnit = (wheelPixelsPerUnit * wheelSamples + sample) / (wheelSamples + 1);
+          ++wheelSamples;
+        }, 200);
+      } else {
+        display.wheelDX += dx; display.wheelDY += dy;
+      }
+    }
+  }
+
+  // KEY EVENTS
+
+  // Run a handler that was bound to a key.
+  function doHandleBinding(cm, bound, dropShift) {
+    if (typeof bound == "string") {
+      bound = commands[bound];
+      if (!bound) return false;
+    }
+    // Ensure previous input has been read, so that the handler sees a
+    // consistent view of the document
+    cm.display.input.ensurePolled();
+    var prevShift = cm.display.shift, done = false;
+    try {
+      if (isReadOnly(cm)) cm.state.suppressEdits = true;
+      if (dropShift) cm.display.shift = false;
+      done = bound(cm) != Pass;
+    } finally {
+      cm.display.shift = prevShift;
+      cm.state.suppressEdits = false;
+    }
+    return done;
+  }
+
+  function lookupKeyForEditor(cm, name, handle) {
+    for (var i = 0; i < cm.state.keyMaps.length; i++) {
+      var result = lookupKey(name, cm.state.keyMaps[i], handle, cm);
+      if (result) return result;
+    }
+    return (cm.options.extraKeys && lookupKey(name, cm.options.extraKeys, handle, cm))
+      || lookupKey(name, cm.options.keyMap, handle, cm);
+  }
+
+  var stopSeq = new Delayed;
+  function dispatchKey(cm, name, e, handle) {
+    var seq = cm.state.keySeq;
+    if (seq) {
+      if (isModifierKey(name)) return "handled";
+      stopSeq.set(50, function() {
+        if (cm.state.keySeq == seq) {
+          cm.state.keySeq = null;
+          cm.display.input.reset();
+        }
+      });
+      name = seq + " " + name;
+    }
+    var result = lookupKeyForEditor(cm, name, handle);
+
+    if (result == "multi")
+      cm.state.keySeq = name;
+    if (result == "handled")
+      signalLater(cm, "keyHandled", cm, name, e);
+
+    if (result == "handled" || result == "multi") {
+      e_preventDefault(e);
+      restartBlink(cm);
+    }
+
+    if (seq && !result && /\'$/.test(name)) {
+      e_preventDefault(e);
+      return true;
+    }
+    return !!result;
+  }
+
+  // Handle a key from the keydown event.
+  function handleKeyBinding(cm, e) {
+    var name = keyName(e, true);
+    if (!name) return false;
+
+    if (e.shiftKey && !cm.state.keySeq) {
+      // First try to resolve full name (including 'Shift-'). Failing
+      // that, see if there is a cursor-motion command (starting with
+      // 'go') bound to the keyname without 'Shift-'.
+      return dispatchKey(cm, "Shift-" + name, e, function(b) {return doHandleBinding(cm, b, true);})
+          || dispatchKey(cm, name, e, function(b) {
+               if (typeof b == "string" ? /^go[A-Z]/.test(b) : b.motion)
+                 return doHandleBinding(cm, b);
+             });
+    } else {
+      return dispatchKey(cm, name, e, function(b) { return doHandleBinding(cm, b); });
+    }
+  }
+
+  // Handle a key from the keypress event
+  function handleCharBinding(cm, e, ch) {
+    return dispatchKey(cm, "'" + ch + "'", e,
+                       function(b) { return doHandleBinding(cm, b, true); });
+  }
+
+  var lastStoppedKey = null;
+  function onKeyDown(e) {
+    var cm = this;
+    cm.curOp.focus = activeElt();
+    if (signalDOMEvent(cm, e)) return;
+    // IE does strange things with escape.
+    if (ie && ie_version < 11 && e.keyCode == 27) e.returnValue = false;
+    var code = e.keyCode;
+    cm.display.shift = code == 16 || e.shiftKey;
+    var handled = handleKeyBinding(cm, e);
+    if (presto) {
+      lastStoppedKey = handled ? code : null;
+      // Opera has no cut event... we try to at least catch the key combo
+      if (!handled && code == 88 && !hasCopyEvent && (mac ? e.metaKey : e.ctrlKey))
+        cm.replaceSelection("", null, "cut");
+    }
+
+    // Turn mouse into crosshair when Alt is held on Mac.
+    if (code == 18 && !/\bCodeMirror-crosshair\b/.test(cm.display.lineDiv.className))
+      showCrossHair(cm);
+  }
+
+  function showCrossHair(cm) {
+    var lineDiv = cm.display.lineDiv;
+    addClass(lineDiv, "CodeMirror-crosshair");
+
+    function up(e) {
+      if (e.keyCode == 18 || !e.altKey) {
+        rmClass(lineDiv, "CodeMirror-crosshair");
+        off(document, "keyup", up);
+        off(document, "mouseover", up);
+      }
+    }
+    on(document, "keyup", up);
+    on(document, "mouseover", up);
+  }
+
+  function onKeyUp(e) {
+    if (e.keyCode == 16) this.doc.sel.shift = false;
+    signalDOMEvent(this, e);
+  }
+
+  function onKeyPress(e) {
+    var cm = this;
+    if (eventInWidget(cm.display, e) || signalDOMEvent(cm, e) || e.ctrlKey && !e.altKey || mac && e.metaKey) return;
+    var keyCode = e.keyCode, charCode = e.charCode;
+    if (presto && keyCode == lastStoppedKey) {lastStoppedKey = null; e_preventDefault(e); return;}
+    if ((presto && (!e.which || e.which < 10)) && handleKeyBinding(cm, e)) return;
+    var ch = String.fromCharCode(charCode == null ? keyCode : charCode);
+    if (handleCharBinding(cm, e, ch)) return;
+    cm.display.input.onKeyPress(e);
+  }
+
+  // FOCUS/BLUR EVENTS
+
+  function delayBlurEvent(cm) {
+    cm.state.delayingBlurEvent = true;
+    setTimeout(function() {
+      if (cm.state.delayingBlurEvent) {
+        cm.state.delayingBlurEvent = false;
+        onBlur(cm);
+      }
+    }, 100);
+  }
+
+  function onFocus(cm) {
+    if (cm.state.delayingBlurEvent) cm.state.delayingBlurEvent = false;
+
+    if (cm.options.readOnly == "nocursor") return;
+    if (!cm.state.focused) {
+      signal(cm, "focus", cm);
+      cm.state.focused = true;
+      addClass(cm.display.wrapper, "CodeMirror-focused");
+      // This test prevents this from firing when a context
+      // menu is closed (since the input reset would kill the
+      // select-all detection hack)
+      if (!cm.curOp && cm.display.selForContextMenu != cm.doc.sel) {
+        cm.display.input.reset();
+        if (webkit) setTimeout(function() { cm.display.input.reset(true); }, 20); // Issue #1730
+      }
+      cm.display.input.receivedFocus();
+    }
+    restartBlink(cm);
+  }
+  function onBlur(cm) {
+    if (cm.state.delayingBlurEvent) return;
+
+    if (cm.state.focused) {
+      signal(cm, "blur", cm);
+      cm.state.focused = false;
+      rmClass(cm.display.wrapper, "CodeMirror-focused");
+    }
+    clearInterval(cm.display.blinker);
+    setTimeout(function() {if (!cm.state.focused) cm.display.shift = false;}, 150);
+  }
+
+  // CONTEXT MENU HANDLING
+
+  // To make the context menu work, we need to briefly unhide the
+  // textarea (making it as unobtrusive as possible) to let the
+  // right-click take effect on it.
+  function onContextMenu(cm, e) {
+    if (eventInWidget(cm.display, e) || contextMenuInGutter(cm, e)) return;
+    cm.display.input.onContextMenu(e);
+  }
+
+  function contextMenuInGutter(cm, e) {
+    if (!hasHandler(cm, "gutterContextMenu")) return false;
+    return gutterEvent(cm, e, "gutterContextMenu", false, signal);
+  }
+
+  // UPDATING
+
+  // Compute the position of the end of a change (its 'to' property
+  // refers to the pre-change end).
+  var changeEnd = CodeMirror.changeEnd = function(change) {
+    if (!change.text) return change.to;
+    return Pos(change.from.line + change.text.length - 1,
+               lst(change.text).length + (change.text.length == 1 ? change.from.ch : 0));
+  };
+
+  // Adjust a position to refer to the post-change position of the
+  // same text, or the end of the change if the change covers it.
+  function adjustForChange(pos, change) {
+    if (cmp(pos, change.from) < 0) return pos;
+    if (cmp(pos, change.to) <= 0) return changeEnd(change);
+
+    var line = pos.line + change.text.length - (change.to.line - change.from.line) - 1, ch = pos.ch;
+    if (pos.line == change.to.line) ch += changeEnd(change).ch - change.to.ch;
+    return Pos(line, ch);
+  }
+
+  function computeSelAfterChange(doc, change) {
+    var out = [];
+    for (var i = 0; i < doc.sel.ranges.length; i++) {
+      var range = doc.sel.ranges[i];
+      out.push(new Range(adjustForChange(range.anchor, change),
+                         adjustForChange(range.head, change)));
+    }
+    return normalizeSelection(out, doc.sel.primIndex);
+  }
+
+  function offsetPos(pos, old, nw) {
+    if (pos.line == old.line)
+      return Pos(nw.line, pos.ch - old.ch + nw.ch);
+    else
+      return Pos(nw.line + (pos.line - old.line), pos.ch);
+  }
+
+  // Used by replaceSelections to allow moving the selection to the
+  // start or around the replaced test. Hint may be "start" or "around".
+  function computeReplacedSel(doc, changes, hint) {
+    var out = [];
+    var oldPrev = Pos(doc.first, 0), newPrev = oldPrev;
+    for (var i = 0; i < changes.length; i++) {
+      var change = changes[i];
+      var from = offsetPos(change.from, oldPrev, newPrev);
+      var to = offsetPos(changeEnd(change), oldPrev, newPrev);
+      oldPrev = change.to;
+      newPrev = to;
+      if (hint == "around") {
+        var range = doc.sel.ranges[i], inv = cmp(range.head, range.anchor) < 0;
+        out[i] = new Range(inv ? to : from, inv ? from : to);
+      } else {
+        out[i] = new Range(from, from);
+      }
+    }
+    return new Selection(out, doc.sel.primIndex);
+  }
+
+  // Allow "beforeChange" event handlers to influence a change
+  function filterChange(doc, change, update) {
+    var obj = {
+      canceled: false,
+      from: change.from,
+      to: change.to,
+      text: change.text,
+      origin: change.origin,
+      cancel: function() { this.canceled = true; }
+    };
+    if (update) obj.update = function(from, to, text, origin) {
+      if (from) this.from = clipPos(doc, from);
+      if (to) this.to = clipPos(doc, to);
+      if (text) this.text = text;
+      if (origin !== undefined) this.origin = origin;
+    };
+    signal(doc, "beforeChange", doc, obj);
+    if (doc.cm) signal(doc.cm, "beforeChange", doc.cm, obj);
+
+    if (obj.canceled) return null;
+    return {from: obj.from, to: obj.to, text: obj.text, origin: obj.origin};
+  }
+
+  // Apply a change to a document, and add it to the document's
+  // history, and propagating it to all linked documents.
+  function makeChange(doc, change, ignoreReadOnly) {
+    if (doc.cm) {
+      if (!doc.cm.curOp) return operation(doc.cm, makeChange)(doc, change, ignoreReadOnly);
+      if (doc.cm.state.suppressEdits) return;
+    }
+
+    if (hasHandler(doc, "beforeChange") || doc.cm && hasHandler(doc.cm, "beforeChange")) {
+      change = filterChange(doc, change, true);
+      if (!change) return;
+    }
+
+    // Possibly split or suppress the update based on the presence
+    // of read-only spans in its range.
+    var split = sawReadOnlySpans && !ignoreReadOnly && removeReadOnlyRanges(doc, change.from, change.to);
+    if (split) {
+      for (var i = split.length - 1; i >= 0; --i)
+        makeChangeInner(doc, {from: split[i].from, to: split[i].to, text: i ? [""] : change.text});
+    } else {
+      makeChangeInner(doc, change);
+    }
+  }
+
+  function makeChangeInner(doc, change) {
+    if (change.text.length == 1 && change.text[0] == "" && cmp(change.from, change.to) == 0) return;
+    var selAfter = computeSelAfterChange(doc, change);
+    addChangeToHistory(doc, change, selAfter, doc.cm ? doc.cm.curOp.id : NaN);
+
+    makeChangeSingleDoc(doc, change, selAfter, stretchSpansOverChange(doc, change));
+    var rebased = [];
+
+    linkedDocs(doc, function(doc, sharedHist) {
+      if (!sharedHist && indexOf(rebased, doc.history) == -1) {
+        rebaseHist(doc.history, change);
+        rebased.push(doc.history);
+      }
+      makeChangeSingleDoc(doc, change, null, stretchSpansOverChange(doc, change));
+    });
+  }
+
+  // Revert a change stored in a document's history.
+  function makeChangeFromHistory(doc, type, allowSelectionOnly) {
+    if (doc.cm && doc.cm.state.suppressEdits) return;
+
+    var hist = doc.history, event, selAfter = doc.sel;
+    var source = type == "undo" ? hist.done : hist.undone, dest = type == "undo" ? hist.undone : hist.done;
+
+    // Verify that there is a useable event (so that ctrl-z won't
+    // needlessly clear selection events)
+    for (var i = 0; i < source.length; i++) {
+      event = source[i];
+      if (allowSelectionOnly ? event.ranges && !event.equals(doc.sel) : !event.ranges)
+        break;
+    }
+    if (i == source.length) return;
+    hist.lastOrigin = hist.lastSelOrigin = null;
+
+    for (;;) {
+      event = source.pop();
+      if (event.ranges) {
+        pushSelectionToHistory(event, dest);
+        if (allowSelectionOnly && !event.equals(doc.sel)) {
+          setSelection(doc, event, {clearRedo: false});
+          return;
+        }
+        selAfter = event;
+      }
+      else break;
+    }
+
+    // Build up a reverse change object to add to the opposite history
+    // stack (redo when undoing, and vice versa).
+    var antiChanges = [];
+    pushSelectionToHistory(selAfter, dest);
+    dest.push({changes: antiChanges, generation: hist.generation});
+    hist.generation = event.generation || ++hist.maxGeneration;
+
+    var filter = hasHandler(doc, "beforeChange") || doc.cm && hasHandler(doc.cm, "beforeChange");
+
+    for (var i = event.changes.length - 1; i >= 0; --i) {
+      var change = event.changes[i];
+      change.origin = type;
+      if (filter && !filterChange(doc, change, false)) {
+        source.length = 0;
+        return;
+      }
+
+      antiChanges.push(historyChangeFromChange(doc, change));
+
+      var after = i ? computeSelAfterChange(doc, change) : lst(source);
+      makeChangeSingleDoc(doc, change, after, mergeOldSpans(doc, change));
+      if (!i && doc.cm) doc.cm.scrollIntoView({from: change.from, to: changeEnd(change)});
+      var rebased = [];
+
+      // Propagate to the linked documents
+      linkedDocs(doc, function(doc, sharedHist) {
+        if (!sharedHist && indexOf(rebased, doc.history) == -1) {
+          rebaseHist(doc.history, change);
+          rebased.push(doc.history);
+        }
+        makeChangeSingleDoc(doc, change, null, mergeOldSpans(doc, change));
+      });
+    }
+  }
+
+  // Sub-views need their line numbers shifted when text is added
+  // above or below them in the parent document.
+  function shiftDoc(doc, distance) {
+    if (distance == 0) return;
+    doc.first += distance;
+    doc.sel = new Selection(map(doc.sel.ranges, function(range) {
+      return new Range(Pos(range.anchor.line + distance, range.anchor.ch),
+                       Pos(range.head.line + distance, range.head.ch));
+    }), doc.sel.primIndex);
+    if (doc.cm) {
+      regChange(doc.cm, doc.first, doc.first - distance, distance);
+      for (var d = doc.cm.display, l = d.viewFrom; l < d.viewTo; l++)
+        regLineChange(doc.cm, l, "gutter");
+    }
+  }
+
+  // More lower-level change function, handling only a single document
+  // (not linked ones).
+  function makeChangeSingleDoc(doc, change, selAfter, spans) {
+    if (doc.cm && !doc.cm.curOp)
+      return operation(doc.cm, makeChangeSingleDoc)(doc, change, selAfter, spans);
+
+    if (change.to.line < doc.first) {
+      shiftDoc(doc, change.text.length - 1 - (change.to.line - change.from.line));
+      return;
+    }
+    if (change.from.line > doc.lastLine()) return;
+
+    // Clip the change to the size of this doc
+    if (change.from.line < doc.first) {
+      var shift = change.text.length - 1 - (doc.first - change.from.line);
+      shiftDoc(doc, shift);
+      change = {from: Pos(doc.first, 0), to: Pos(change.to.line + shift, change.to.ch),
+                text: [lst(change.text)], origin: change.origin};
+    }
+    var last = doc.lastLine();
+    if (change.to.line > last) {
+      change = {from: change.from, to: Pos(last, getLine(doc, last).text.length),
+                text: [change.text[0]], origin: change.origin};
+    }
+
+    change.removed = getBetween(doc, change.from, change.to);
+
+    if (!selAfter) selAfter = computeSelAfterChange(doc, change);
+    if (doc.cm) makeChangeSingleDocInEditor(doc.cm, change, spans);
+    else updateDoc(doc, change, spans);
+    setSelectionNoUndo(doc, selAfter, sel_dontScroll);
+  }
+
+  // Handle the interaction of a change to a document with the editor
+  // that this document is part of.
+  function makeChangeSingleDocInEditor(cm, change, spans) {
+    var doc = cm.doc, display = cm.display, from = change.from, to = change.to;
+
+    var recomputeMaxLength = false, checkWidthStart = from.line;
+    if (!cm.options.lineWrapping) {
+      checkWidthStart = lineNo(visualLine(getLine(doc, from.line)));
+      doc.iter(checkWidthStart, to.line + 1, function(line) {
+        if (line == display.maxLine) {
+          recomputeMaxLength = true;
+          return true;
+        }
+      });
+    }
+
+    if (doc.sel.contains(change.from, change.to) > -1)
+      signalCursorActivity(cm);
+
+    updateDoc(doc, change, spans, estimateHeight(cm));
+
+    if (!cm.options.lineWrapping) {
+      doc.iter(checkWidthStart, from.line + change.text.length, function(line) {
+        var len = lineLength(line);
+        if (len > display.maxLineLength) {
+          display.maxLine = line;
+          display.maxLineLength = len;
+          display.maxLineChanged = true;
+          recomputeMaxLength = false;
+        }
+      });
+      if (recomputeMaxLength) cm.curOp.updateMaxLine = true;
+    }
+
+    // Adjust frontier, schedule worker
+    doc.frontier = Math.min(doc.frontier, from.line);
+    startWorker(cm, 400);
+
+    var lendiff = change.text.length - (to.line - from.line) - 1;
+    // Remember that these lines changed, for updating the display
+    if (change.full)
+      regChange(cm);
+    else if (from.line == to.line && change.text.length == 1 && !isWholeLineUpdate(cm.doc, change))
+      regLineChange(cm, from.line, "text");
+    else
+      regChange(cm, from.line, to.line + 1, lendiff);
+
+    var changesHandler = hasHandler(cm, "changes"), changeHandler = hasHandler(cm, "change");
+    if (changeHandler || changesHandler) {
+      var obj = {
+        from: from, to: to,
+        text: change.text,
+        removed: change.removed,
+        origin: change.origin
+      };
+      if (changeHandler) signalLater(cm, "change", cm, obj);
+      if (changesHandler) (cm.curOp.changeObjs || (cm.curOp.changeObjs = [])).push(obj);
+    }
+    cm.display.selForContextMenu = null;
+  }
+
+  function replaceRange(doc, code, from, to, origin) {
+    if (!to) to = from;
+    if (cmp(to, from) < 0) { var tmp = to; to = from; from = tmp; }
+    if (typeof code == "string") code = splitLines(code);
+    makeChange(doc, {from: from, to: to, text: code, origin: origin});
+  }
+
+  // SCROLLING THINGS INTO VIEW
+
+  // If an editor sits on the top or bottom of the window, partially
+  // scrolled out of view, this ensures that the cursor is visible.
+  function maybeScrollWindow(cm, coords) {
+    if (signalDOMEvent(cm, "scrollCursorIntoView")) return;
+
+    var display = cm.display, box = display.sizer.getBoundingClientRect(), doScroll = null;
+    if (coords.top + box.top < 0) doScroll = true;
+    else if (coords.bottom + box.top > (window.innerHeight || document.documentElement.clientHeight)) doScroll = false;
+    if (doScroll != null && !phantom) {
+      var scrollNode = elt("div", "\u200b", null, "position: absolute; top: " +
+                           (coords.top - display.viewOffset - paddingTop(cm.display)) + "px; height: " +
+                           (coords.bottom - coords.top + scrollGap(cm) + display.barHeight) + "px; left: " +
+                           coords.left + "px; width: 2px;");
+      cm.display.lineSpace.appendChild(scrollNode);
+      scrollNode.scrollIntoView(doScroll);
+      cm.display.lineSpace.removeChild(scrollNode);
+    }
+  }
+
+  // Scroll a given position into view (immediately), verifying that
+  // it actually became visible (as line heights are accurately
+  // measured, the position of something may 'drift' during drawing).
+  function scrollPosIntoView(cm, pos, end, margin) {
+    if (margin == null) margin = 0;
+    for (var limit = 0; limit < 5; limit++) {
+      var changed = false, coords = cursorCoords(cm, pos);
+      var endCoords = !end || end == pos ? coords : cursorCoords(cm, end);
+      var scrollPos = calculateScrollPos(cm, Math.min(coords.left, endCoords.left),
+                                         Math.min(coords.top, endCoords.top) - margin,
+                                         Math.max(coords.left, endCoords.left),
+                                         Math.max(coords.bottom, endCoords.bottom) + margin);
+      var startTop = cm.doc.scrollTop, startLeft = cm.doc.scrollLeft;
+      if (scrollPos.scrollTop != null) {
+        setScrollTop(cm, scrollPos.scrollTop);
+        if (Math.abs(cm.doc.scrollTop - startTop) > 1) changed = true;
+      }
+      if (scrollPos.scrollLeft != null) {
+        setScrollLeft(cm, scrollPos.scrollLeft);
+        if (Math.abs(cm.doc.scrollLeft - startLeft) > 1) changed = true;
+      }
+      if (!changed) break;
+    }
+    return coords;
+  }
+
+  // Scroll a given set of coordinates into view (immediately).
+  function scrollIntoView(cm, x1, y1, x2, y2) {
+    var scrollPos = calculateScrollPos(cm, x1, y1, x2, y2);
+    if (scrollPos.scrollTop != null) setScrollTop(cm, scrollPos.scrollTop);
+    if (scrollPos.scrollLeft != null) setScrollLeft(cm, scrollPos.scrollLeft);
+  }
+
+  // Calculate a new scroll position needed to scroll the given
+  // rectangle into view. Returns an object with scrollTop and
+  // scrollLeft properties. When these are undefined, the
+  // vertical/horizontal position does not need to be adjusted.
+  function calculateScrollPos(cm, x1, y1, x2, y2) {
+    var display = cm.display, snapMargin = textHeight(cm.display);
+    if (y1 < 0) y1 = 0;
+    var screentop = cm.curOp && cm.curOp.scrollTop != null ? cm.curOp.scrollTop : display.scroller.scrollTop;
+    var screen = displayHeight(cm), result = {};
+    if (y2 - y1 > screen) y2 = y1 + screen;
+    var docBottom = cm.doc.height + paddingVert(display);
+    var atTop = y1 < snapMargin, atBottom = y2 > docBottom - snapMargin;
+    if (y1 < screentop) {
+      result.scrollTop = atTop ? 0 : y1;
+    } else if (y2 > screentop + screen) {
+      var newTop = Math.min(y1, (atBottom ? docBottom : y2) - screen);
+      if (newTop != screentop) result.scrollTop = newTop;
+    }
+
+    var screenleft = cm.curOp && cm.curOp.scrollLeft != null ? cm.curOp.scrollLeft : display.scroller.scrollLeft;
+    var screenw = displayWidth(cm) - (cm.options.fixedGutter ? display.gutters.offsetWidth : 0);
+    var tooWide = x2 - x1 > screenw;
+    if (tooWide) x2 = x1 + screenw;
+    if (x1 < 10)
+      result.scrollLeft = 0;
+    else if (x1 < screenleft)
+      result.scrollLeft = Math.max(0, x1 - (tooWide ? 0 : 10));
+    else if (x2 > screenw + screenleft - 3)
+      result.scrollLeft = x2 + (tooWide ? 0 : 10) - screenw;
+    return result;
+  }
+
+  // Store a relative adjustment to the scroll position in the current
+  // operation (to be applied when the operation finishes).
+  function addToScrollPos(cm, left, top) {
+    if (left != null || top != null) resolveScrollToPos(cm);
+    if (left != null)
+      cm.curOp.scrollLeft = (cm.curOp.scrollLeft == null ? cm.doc.scrollLeft : cm.curOp.scrollLeft) + left;
+    if (top != null)
+      cm.curOp.scrollTop = (cm.curOp.scrollTop == null ? cm.doc.scrollTop : cm.curOp.scrollTop) + top;
+  }
+
+  // Make sure that at the end of the operation the current cursor is
+  // shown.
+  function ensureCursorVisible(cm) {
+    resolveScrollToPos(cm);
+    var cur = cm.getCursor(), from = cur, to = cur;
+    if (!cm.options.lineWrapping) {
+      from = cur.ch ? Pos(cur.line, cur.ch - 1) : cur;
+      to = Pos(cur.line, cur.ch + 1);
+    }
+    cm.curOp.scrollToPos = {from: from, to: to, margin: cm.options.cursorScrollMargin, isCursor: true};
+  }
+
+  // When an operation has its scrollToPos property set, and another
+  // scroll action is applied before the end of the operation, this
+  // 'simulates' scrolling that position into view in a cheap way, so
+  // that the effect of intermediate scroll commands is not ignored.
+  function resolveScrollToPos(cm) {
+    var range = cm.curOp.scrollToPos;
+    if (range) {
+      cm.curOp.scrollToPos = null;
+      var from = estimateCoords(cm, range.from), to = estimateCoords(cm, range.to);
+      var sPos = calculateScrollPos(cm, Math.min(from.left, to.left),
+                                    Math.min(from.top, to.top) - range.margin,
+                                    Math.max(from.right, to.right),
+                                    Math.max(from.bottom, to.bottom) + range.margin);
+      cm.scrollTo(sPos.scrollLeft, sPos.scrollTop);
+    }
+  }
+
+  // API UTILITIES
+
+  // Indent the given line. The how parameter can be "smart",
+  // "add"/null, "subtract", or "prev". When aggressive is false
+  // (typically set to true for forced single-line indents), empty
+  // lines are not indented, and places where the mode returns Pass
+  // are left alone.
+  function indentLine(cm, n, how, aggressive) {
+    var doc = cm.doc, state;
+    if (how == null) how = "add";
+    if (how == "smart") {
+      // Fall back to "prev" when the mode doesn't have an indentation
+      // method.
+      if (!doc.mode.indent) how = "prev";
+      else state = getStateBefore(cm, n);
+    }
+
+    var tabSize = cm.options.tabSize;
+    var line = getLine(doc, n), curSpace = countColumn(line.text, null, tabSize);
+    if (line.stateAfter) line.stateAfter = null;
+    var curSpaceString = line.text.match(/^\s*/)[0], indentation;
+    if (!aggressive && !/\S/.test(line.text)) {
+      indentation = 0;
+      how = "not";
+    } else if (how == "smart") {
+      indentation = doc.mode.indent(state, line.text.slice(curSpaceString.length), line.text);
+      if (indentation == Pass || indentation > 150) {
+        if (!aggressive) return;
+        how = "prev";
+      }
+    }
+    if (how == "prev") {
+      if (n > doc.first) indentation = countColumn(getLine(doc, n-1).text, null, tabSize);
+      else indentation = 0;
+    } else if (how == "add") {
+      indentation = curSpace + cm.options.indentUnit;
+    } else if (how == "subtract") {
+      indentation = curSpace - cm.options.indentUnit;
+    } else if (typeof how == "number") {
+      indentation = curSpace + how;
+    }
+    indentation = Math.max(0, indentation);
+
+    var indentString = "", pos = 0;
+    if (cm.options.indentWithTabs)
+      for (var i = Math.floor(indentation / tabSize); i; --i) {pos += tabSize; indentString += "\t";}
+    if (pos < indentation) indentString += spaceStr(indentation - pos);
+
+    if (indentString != curSpaceString) {
+      replaceRange(doc, indentString, Pos(n, 0), Pos(n, curSpaceString.length), "+input");
+      line.stateAfter = null;
+      return true;
+    } else {
+      // Ensure that, if the cursor was in the whitespace at the start
+      // of the line, it is moved to the end of that space.
+      for (var i = 0; i < doc.sel.ranges.length; i++) {
+        var range = doc.sel.ranges[i];
+        if (range.head.line == n && range.head.ch < curSpaceString.length) {
+          var pos = Pos(n, curSpaceString.length);
+          replaceOneSelection(doc, i, new Range(pos, pos));
+          break;
+        }
+      }
+    }
+  }
+
+  // Utility for applying a change to a line by handle or number,
+  // returning the number and optionally registering the line as
+  // changed.
+  function changeLine(doc, handle, changeType, op) {
+    var no = handle, line = handle;
+    if (typeof handle == "number") line = getLine(doc, clipLine(doc, handle));
+    else no = lineNo(handle);
+    if (no == null) return null;
+    if (op(line, no) && doc.cm) regLineChange(doc.cm, no, changeType);
+    return line;
+  }
+
+  // Helper for deleting text near the selection(s), used to implement
+  // backspace, delete, and similar functionality.
+  function deleteNearSelection(cm, compute) {
+    var ranges = cm.doc.sel.ranges, kill = [];
+    // Build up a set of ranges to kill first, merging overlapping
+    // ranges.
+    for (var i = 0; i < ranges.length; i++) {
+      var toKill = compute(ranges[i]);
+      while (kill.length && cmp(toKill.from, lst(kill).to) <= 0) {
+        var replaced = kill.pop();
+        if (cmp(replaced.from, toKill.from) < 0) {
+          toKill.from = replaced.from;
+          break;
+        }
+      }
+      kill.push(toKill);
+    }
+    // Next, remove those actual ranges.
+    runInOp(cm, function() {
+      for (var i = kill.length - 1; i >= 0; i--)
+        replaceRange(cm.doc, "", kill[i].from, kill[i].to, "+delete");
+      ensureCursorVisible(cm);
+    });
+  }
+
+  // Used for horizontal relative motion. Dir is -1 or 1 (left or
+  // right), unit can be "char", "column" (like char, but doesn't
+  // cross line boundaries), "word" (across next word), or "group" (to
+  // the start of next group of word or non-word-non-whitespace
+  // chars). The visually param controls whether, in right-to-left
+  // text, direction 1 means to move towards the next index in the
+  // string, or towards the character to the right of the current
+  // position. The resulting position will have a hitSide=true
+  // property if it reached the end of the document.
+  function findPosH(doc, pos, dir, unit, visually) {
+    var line = pos.line, ch = pos.ch, origDir = dir;
+    var lineObj = getLine(doc, line);
+    var possible = true;
+    function findNextLine() {
+      var l = line + dir;
+      if (l < doc.first || l >= doc.first + doc.size) return (possible = false);
+      line = l;
+      return lineObj = getLine(doc, l);
+    }
+    function moveOnce(boundToLine) {
+      var next = (visually ? moveVisually : moveLogically)(lineObj, ch, dir, true);
+      if (next == null) {
+        if (!boundToLine && findNextLine()) {
+          if (visually) ch = (dir < 0 ? lineRight : lineLeft)(lineObj);
+          else ch = dir < 0 ? lineObj.text.length : 0;
+        } else return (possible = false);
+      } else ch = next;
+      return true;
+    }
+
+    if (unit == "char") moveOnce();
+    else if (unit == "column") moveOnce(true);
+    else if (unit == "word" || unit == "group") {
+      var sawType = null, group = unit == "group";
+      var helper = doc.cm && doc.cm.getHelper(pos, "wordChars");
+      for (var first = true;; first = false) {
+        if (dir < 0 && !moveOnce(!first)) break;
+        var cur = lineObj.text.charAt(ch) || "\n";
+        var type = isWordChar(cur, helper) ? "w"
+          : group && cur == "\n" ? "n"
+          : !group || /\s/.test(cur) ? null
+          : "p";
+        if (group && !first && !type) type = "s";
+        if (sawType && sawType != type) {
+          if (dir < 0) {dir = 1; moveOnce();}
+          break;
+        }
+
+        if (type) sawType = type;
+        if (dir > 0 && !moveOnce(!first)) break;
+      }
+    }
+    var result = skipAtomic(doc, Pos(line, ch), origDir, true);
+    if (!possible) result.hitSide = true;
+    return result;
+  }
+
+  // For relative vertical movement. Dir may be -1 or 1. Unit can be
+  // "page" or "line". The resulting position will have a hitSide=true
+  // property if it reached the end of the document.
+  function findPosV(cm, pos, dir, unit) {
+    var doc = cm.doc, x = pos.left, y;
+    if (unit == "page") {
+      var pageSize = Math.min(cm.display.wrapper.clientHeight, window.innerHeight || document.documentElement.clientHeight);
+      y = pos.top + dir * (pageSize - (dir < 0 ? 1.5 : .5) * textHeight(cm.display));
+    } else if (unit == "line") {
+      y = dir > 0 ? pos.bottom + 3 : pos.top - 3;
+    }
+    for (;;) {
+      var target = coordsChar(cm, x, y);
+      if (!target.outside) break;
+      if (dir < 0 ? y <= 0 : y >= doc.height) { target.hitSide = true; break; }
+      y += dir * 5;
+    }
+    return target;
+  }
+
+  // EDITOR METHODS
+
+  // The publicly visible API. Note that methodOp(f) means
+  // 'wrap f in an operation, performed on its `this` parameter'.
+
+  // This is not the complete set of editor methods. Most of the
+  // methods defined on the Doc type are also injected into
+  // CodeMirror.prototype, for backwards compatibility and
+  // convenience.
+
+  CodeMirror.prototype = {
+    constructor: CodeMirror,
+    focus: function(){window.focus(); this.display.input.focus();},
+
+    setOption: function(option, value) {
+      var options = this.options, old = options[option];
+      if (options[option] == value && option != "mode") return;
+      options[option] = value;
+      if (optionHandlers.hasOwnProperty(option))
+        operation(this, optionHandlers[option])(this, value, old);
+    },
+
+    getOption: function(option) {return this.options[option];},
+    getDoc: function() {return this.doc;},
+
+    addKeyMap: function(map, bottom) {
+      this.state.keyMaps[bottom ? "push" : "unshift"](getKeyMap(map));
+    },
+    removeKeyMap: function(map) {
+      var maps = this.state.keyMaps;
+      for (var i = 0; i < maps.length; ++i)
+        if (maps[i] == map || maps[i].name == map) {
+          maps.splice(i, 1);
+          return true;
+        }
+    },
+
+    addOverlay: methodOp(function(spec, options) {
+      var mode = spec.token ? spec : CodeMirror.getMode(this.options, spec);
+      if (mode.startState) throw new Error("Overlays may not be stateful.");
+      this.state.overlays.push({mode: mode, modeSpec: spec, opaque: options && options.opaque});
+      this.state.modeGen++;
+      regChange(this);
+    }),
+    removeOverlay: methodOp(function(spec) {
+      var overlays = this.state.overlays;
+      for (var i = 0; i < overlays.length; ++i) {
+        var cur = overlays[i].modeSpec;
+        if (cur == spec || typeof spec == "string" && cur.name == spec) {
+          overlays.splice(i, 1);
+          this.state.modeGen++;
+          regChange(this);
+          return;
+        }
+      }
+    }),
+
+    indentLine: methodOp(function(n, dir, aggressive) {
+      if (typeof dir != "string" && typeof dir != "number") {
+        if (dir == null) dir = this.options.smartIndent ? "smart" : "prev";
+        else dir = dir ? "add" : "subtract";
+      }
+      if (isLine(this.doc, n)) indentLine(this, n, dir, aggressive);
+    }),
+    indentSelection: methodOp(function(how) {
+      var ranges = this.doc.sel.ranges, end = -1;
+      for (var i = 0; i < ranges.length; i++) {
+        var range = ranges[i];
+        if (!range.empty()) {
+          var from = range.from(), to = range.to();
+          var start = Math.max(end, from.line);
+          end = Math.min(this.lastLine(), to.line - (to.ch ? 0 : 1)) + 1;
+          for (var j = start; j < end; ++j)
+            indentLine(this, j, how);
+          var newRanges = this.doc.sel.ranges;
+          if (from.ch == 0 && ranges.length == newRanges.length && newRanges[i].from().ch > 0)
+            replaceOneSelection(this.doc, i, new Range(from, newRanges[i].to()), sel_dontScroll);
+        } else if (range.head.line > end) {
+          indentLine(this, range.head.line, how, true);
+          end = range.head.line;
+          if (i == this.doc.sel.primIndex) ensureCursorVisible(this);
+        }
+      }
+    }),
+
+    // Fetch the parser token for a given character. Useful for hacks
+    // that want to inspect the mode state (say, for completion).
+    getTokenAt: function(pos, precise) {
+      return takeToken(this, pos, precise);
+    },
+
+    getLineTokens: function(line, precise) {
+      return takeToken(this, Pos(line), precise, true);
+    },
+
+    getTokenTypeAt: function(pos) {
+      pos = clipPos(this.doc, pos);
+      var styles = getLineStyles(this, getLine(this.doc, pos.line));
+      var before = 0, after = (styles.length - 1) / 2, ch = pos.ch;
+      var type;
+      if (ch == 0) type = styles[2];
+      else for (;;) {
+        var mid = (before + after) >> 1;
+        if ((mid ? styles[mid * 2 - 1] : 0) >= ch) after = mid;
+        else if (styles[mid * 2 + 1] < ch) before = mid + 1;
+        else { type = styles[mid * 2 + 2]; break; }
+      }
+      var cut = type ? type.indexOf("cm-overlay ") : -1;
+      return cut < 0 ? type : cut == 0 ? null : type.slice(0, cut - 1);
+    },
+
+    getModeAt: function(pos) {
+      var mode = this.doc.mode;
+      if (!mode.innerMode) return mode;
+      return CodeMirror.innerMode(mode, this.getTokenAt(pos).state).mode;
+    },
+
+    getHelper: function(pos, type) {
+      return this.getHelpers(pos, type)[0];
+    },
+
+    getHelpers: function(pos, type) {
+      var found = [];
+      if (!helpers.hasOwnProperty(type)) return found;
+      var help = helpers[type], mode = this.getModeAt(pos);
+      if (typeof mode[type] == "string") {
+        if (help[mode[type]]) found.push(help[mode[type]]);
+      } else if (mode[type]) {
+        for (var i = 0; i < mode[type].length; i++) {
+          var val = help[mode[type][i]];
+          if (val) found.push(val);
+        }
+      } else if (mode.helperType && help[mode.helperType]) {
+        found.push(help[mode.helperType]);
+      } else if (help[mode.name]) {
+        found.push(help[mode.name]);
+      }
+      for (var i = 0; i < help._global.length; i++) {
+        var cur = help._global[i];
+        if (cur.pred(mode, this) && indexOf(found, cur.val) == -1)
+          found.push(cur.val);
+      }
+      return found;
+    },
+
+    getStateAfter: function(line, precise) {
+      var doc = this.doc;
+      line = clipLine(doc, line == null ? doc.first + doc.size - 1: line);
+      return getStateBefore(this, line + 1, precise);
+    },
+
+    cursorCoords: function(start, mode) {
+      var pos, range = this.doc.sel.primary();
+      if (start == null) pos = range.head;
+      else if (typeof start == "object") pos = clipPos(this.doc, start);
+      else pos = start ? range.from() : range.to();
+      return cursorCoords(this, pos, mode || "page");
+    },
+
+    charCoords: function(pos, mode) {
+      return charCoords(this, clipPos(this.doc, pos), mode || "page");
+    },
+
+    coordsChar: function(coords, mode) {
+      coords = fromCoordSystem(this, coords, mode || "page");
+      return coordsChar(this, coords.left, coords.top);
+    },
+
+    lineAtHeight: function(height, mode) {
+      height = fromCoordSystem(this, {top: height, left: 0}, mode || "page").top;
+      return lineAtHeight(this.doc, height + this.display.viewOffset);
+    },
+    heightAtLine: function(line, mode) {
+      var end = false, lineObj;
+      if (typeof line == "number") {
+        var last = this.doc.first + this.doc.size - 1;
+        if (line < this.doc.first) line = this.doc.first;
+        else if (line > last) { line = last; end = true; }
+        lineObj = getLine(this.doc, line);
+      } else {
+        lineObj = line;
+      }
+      return intoCoordSystem(this, lineObj, {top: 0, left: 0}, mode || "page").top +
+        (end ? this.doc.height - heightAtLine(lineObj) : 0);
+    },
+
+    defaultTextHeight: function() { return textHeight(this.display); },
+    defaultCharWidth: function() { return charWidth(this.display); },
+
+    setGutterMarker: methodOp(function(line, gutterID, value) {
+      return changeLine(this.doc, line, "gutter", function(line) {
+        var markers = line.gutterMarkers || (line.gutterMarkers = {});
+        markers[gutterID] = value;
+        if (!value && isEmpty(markers)) line.gutterMarkers = null;
+        return true;
+      });
+    }),
+
+    clearGutter: methodOp(function(gutterID) {
+      var cm = this, doc = cm.doc, i = doc.first;
+      doc.iter(function(line) {
+        if (line.gutterMarkers && line.gutterMarkers[gutterID]) {
+          line.gutterMarkers[gutterID] = null;
+          regLineChange(cm, i, "gutter");
+          if (isEmpty(line.gutterMarkers)) line.gutterMarkers = null;
+        }
+        ++i;
+      });
+    }),
+
+    lineInfo: function(line) {
+      if (typeof line == "number") {
+        if (!isLine(this.doc, line)) return null;
+        var n = line;
+        line = getLine(this.doc, line);
+        if (!line) return null;
+      } else {
+        var n = lineNo(line);
+        if (n == null) return null;
+      }
+      return {line: n, handle: line, text: line.text, gutterMarkers: line.gutterMarkers,
+              textClass: line.textClass, bgClass: line.bgClass, wrapClass: line.wrapClass,
+              widgets: line.widgets};
+    },
+
+    getViewport: function() { return {from: this.display.viewFrom, to: this.display.viewTo};},
+
+    addWidget: function(pos, node, scroll, vert, horiz) {
+      var display = this.display;
+      pos = cursorCoords(this, clipPos(this.doc, pos));
+      var top = pos.bottom, left = pos.left;
+      node.style.position = "absolute";
+      node.setAttribute("cm-ignore-events", "true");
+      this.display.input.setUneditable(node);
+      display.sizer.appendChild(node);
+      if (vert == "over") {
+        top = pos.top;
+      } else if (vert == "above" || vert == "near") {
+        var vspace = Math.max(display.wrapper.clientHeight, this.doc.height),
+        hspace = Math.max(display.sizer.clientWidth, display.lineSpace.clientWidth);
+        // Default to positioning above (if specified and possible); otherwise default to positioning below
+        if ((vert == 'above' || pos.bottom + node.offsetHeight > vspace) && pos.top > node.offsetHeight)
+          top = pos.top - node.offsetHeight;
+        else if (pos.bottom + node.offsetHeight <= vspace)
+          top = pos.bottom;
+        if (left + node.offsetWidth > hspace)
+          left = hspace - node.offsetWidth;
+      }
+      node.style.top = top + "px";
+      node.style.left = node.style.right = "";
+      if (horiz == "right") {
+        left = display.sizer.clientWidth - node.offsetWidth;
+        node.style.right = "0px";
+      } else {
+        if (horiz == "left") left = 0;
+        else if (horiz == "middle") left = (display.sizer.clientWidth - node.offsetWidth) / 2;
+        node.style.left = left + "px";
+      }
+      if (scroll)
+        scrollIntoView(this, left, top, left + node.offsetWidth, top + node.offsetHeight);
+    },
+
+    triggerOnKeyDown: methodOp(onKeyDown),
+    triggerOnKeyPress: methodOp(onKeyPress),
+    triggerOnKeyUp: onKeyUp,
+
+    execCommand: function(cmd) {
+      if (commands.hasOwnProperty(cmd))
+        return commands[cmd](this);
+    },
+
+    triggerElectric: methodOp(function(text) { triggerElectric(this, text); }),
+
+    findPosH: function(from, amount, unit, visually) {
+      var dir = 1;
+      if (amount < 0) { dir = -1; amount = -amount; }
+      for (var i = 0, cur = clipPos(this.doc, from); i < amount; ++i) {
+        cur = findPosH(this.doc, cur, dir, unit, visually);
+        if (cur.hitSide) break;
+      }
+      return cur;
+    },
+
+    moveH: methodOp(function(dir, unit) {
+      var cm = this;
+      cm.extendSelectionsBy(function(range) {
+        if (cm.display.shift || cm.doc.extend || range.empty())
+          return findPosH(cm.doc, range.head, dir, unit, cm.options.rtlMoveVisually);
+        else
+          return dir < 0 ? range.from() : range.to();
+      }, sel_move);
+    }),
+
+    deleteH: methodOp(function(dir, unit) {
+      var sel = this.doc.sel, doc = this.doc;
+      if (sel.somethingSelected())
+        doc.replaceSelection("", null, "+delete");
+      else
+        deleteNearSelection(this, function(range) {
+          var other = findPosH(doc, range.head, dir, unit, false);
+          return dir < 0 ? {from: other, to: range.head} : {from: range.head, to: other};
+        });
+    }),
+
+    findPosV: function(from, amount, unit, goalColumn) {
+      var dir = 1, x = goalColumn;
+      if (amount < 0) { dir = -1; amount = -amount; }
+      for (var i = 0, cur = clipPos(this.doc, from); i < amount; ++i) {
+        var coords = cursorCoords(this, cur, "div");
+        if (x == null) x = coords.left;
+        else coords.left = x;
+        cur = findPosV(this, coords, dir, unit);
+        if (cur.hitSide) break;
+      }
+      return cur;
+    },
+
+    moveV: methodOp(function(dir, unit) {
+      var cm = this, doc = this.doc, goals = [];
+      var collapse = !cm.display.shift && !doc.extend && doc.sel.somethingSelected();
+      doc.extendSelectionsBy(function(range) {
+        if (collapse)
+          return dir < 0 ? range.from() : range.to();
+        var headPos = cursorCoords(cm, range.head, "div");
+        if (range.goalColumn != null) headPos.left = range.goalColumn;
+        goals.push(headPos.left);
+        var pos = findPosV(cm, headPos, dir, unit);
+        if (unit == "page" && range == doc.sel.primary())
+          addToScrollPos(cm, null, charCoords(cm, pos, "div").top - headPos.top);
+        return pos;
+      }, sel_move);
+      if (goals.length) for (var i = 0; i < doc.sel.ranges.length; i++)
+        doc.sel.ranges[i].goalColumn = goals[i];
+    }),
+
+    // Find the word at the given position (as returned by coordsChar).
+    findWordAt: function(pos) {
+      var doc = this.doc, line = getLine(doc, pos.line).text;
+      var start = pos.ch, end = pos.ch;
+      if (line) {
+        var helper = this.getHelper(pos, "wordChars");
+        if ((pos.xRel < 0 || end == line.length) && start) --start; else ++end;
+        var startChar = line.charAt(start);
+        var check = isWordChar(startChar, helper)
+          ? function(ch) { return isWordChar(ch, helper); }
+          : /\s/.test(startChar) ? function(ch) {return /\s/.test(ch);}
+          : function(ch) {return !/\s/.test(ch) && !isWordChar(ch);};
+        while (start > 0 && check(line.charAt(start - 1))) --start;
+        while (end < line.length && check(line.charAt(end))) ++end;
+      }
+      return new Range(Pos(pos.line, start), Pos(pos.line, end));
+    },
+
+    toggleOverwrite: function(value) {
+      if (value != null && value == this.state.overwrite) return;
+      if (this.state.overwrite = !this.state.overwrite)
+        addClass(this.display.cursorDiv, "CodeMirror-overwrite");
+      else
+        rmClass(this.display.cursorDiv, "CodeMirror-overwrite");
+
+      signal(this, "overwriteToggle", this, this.state.overwrite);
+    },
+    hasFocus: function() { return this.display.input.getField() == activeElt(); },
+
+    scrollTo: methodOp(function(x, y) {
+      if (x != null || y != null) resolveScrollToPos(this);
+      if (x != null) this.curOp.scrollLeft = x;
+      if (y != null) this.curOp.scrollTop = y;
+    }),
+    getScrollInfo: function() {
+      var scroller = this.display.scroller;
+      return {left: scroller.scrollLeft, top: scroller.scrollTop,
+              height: scroller.scrollHeight - scrollGap(this) - this.display.barHeight,
+              width: scroller.scrollWidth - scrollGap(this) - this.display.barWidth,
+              clientHeight: displayHeight(this), clientWidth: displayWidth(this)};
+    },
+
+    scrollIntoView: methodOp(function(range, margin) {
+      if (range == null) {
+        range = {from: this.doc.sel.primary().head, to: null};
+        if (margin == null) margin = this.options.cursorScrollMargin;
+      } else if (typeof range == "number") {
+        range = {from: Pos(range, 0), to: null};
+      } else if (range.from == null) {
+        range = {from: range, to: null};
+      }
+      if (!range.to) range.to = range.from;
+      range.margin = margin || 0;
+
+      if (range.from.line != null) {
+        resolveScrollToPos(this);
+        this.curOp.scrollToPos = range;
+      } else {
+        var sPos = calculateScrollPos(this, Math.min(range.from.left, range.to.left),
+                                      Math.min(range.from.top, range.to.top) - range.margin,
+                                      Math.max(range.from.right, range.to.right),
+                                      Math.max(range.from.bottom, range.to.bottom) + range.margin);
+        this.scrollTo(sPos.scrollLeft, sPos.scrollTop);
+      }
+    }),
+
+    setSize: methodOp(function(width, height) {
+      var cm = this;
+      function interpret(val) {
+        return typeof val == "number" || /^\d+$/.test(String(val)) ? val + "px" : val;
+      }
+      if (width != null) cm.display.wrapper.style.width = interpret(width);
+      if (height != null) cm.display.wrapper.style.height = interpret(height);
+      if (cm.options.lineWrapping) clearLineMeasurementCache(this);
+      var lineNo = cm.display.viewFrom;
+      cm.doc.iter(lineNo, cm.display.viewTo, function(line) {
+        if (line.widgets) for (var i = 0; i < line.widgets.length; i++)
+          if (line.widgets[i].noHScroll) { regLineChange(cm, lineNo, "widget"); break; }
+        ++lineNo;
+      });
+      cm.curOp.forceUpdate = true;
+      signal(cm, "refresh", this);
+    }),
+
+    operation: function(f){return runInOp(this, f);},
+
+    refresh: methodOp(function() {
+      var oldHeight = this.display.cachedTextHeight;
+      regChange(this);
+      this.curOp.forceUpdate = true;
+      clearCaches(this);
+      this.scrollTo(this.doc.scrollLeft, this.doc.scrollTop);
+      updateGutterSpace(this);
+      if (oldHeight == null || Math.abs(oldHeight - textHeight(this.display)) > .5)
+        estimateLineHeights(this);
+      signal(this, "refresh", this);
+    }),
+
+    swapDoc: methodOp(function(doc) {
+      var old = this.doc;
+      old.cm = null;
+      attachDoc(this, doc);
+      clearCaches(this);
+      this.display.input.reset();
+      this.scrollTo(doc.scrollLeft, doc.scrollTop);
+      this.curOp.forceScroll = true;
+      signalLater(this, "swapDoc", this, old);
+      return old;
+    }),
+
+    getInputField: function(){return this.display.input.getField();},
+    getWrapperElement: function(){return this.display.wrapper;},
+    getScrollerElement: function(){return this.display.scroller;},
+    getGutterElement: function(){return this.display.gutters;}
+  };
+  eventMixin(CodeMirror);
+
+  // OPTION DEFAULTS
+
+  // The default configuration options.
+  var defaults = CodeMirror.defaults = {};
+  // Functions to run when options are changed.
+  var optionHandlers = CodeMirror.optionHandlers = {};
+
+  function option(name, deflt, handle, notOnInit) {
+    CodeMirror.defaults[name] = deflt;
+    if (handle) optionHandlers[name] =
+      notOnInit ? function(cm, val, old) {if (old != Init) handle(cm, val, old);} : handle;
+  }
+
+  // Passed to option handlers when there is no old value.
+  var Init = CodeMirror.Init = {toString: function(){return "CodeMirror.Init";}};
+
+  // These two are, on init, called from the constructor because they
+  // have to be initialized before the editor can start at all.
+  option("value", "", function(cm, val) {
+    cm.setValue(val);
+  }, true);
+  option("mode", null, function(cm, val) {
+    cm.doc.modeOption = val;
+    loadMode(cm);
+  }, true);
+
+  option("indentUnit", 2, loadMode, true);
+  option("indentWithTabs", false);
+  option("smartIndent", true);
+  option("tabSize", 4, function(cm) {
+    resetModeState(cm);
+    clearCaches(cm);
+    regChange(cm);
+  }, true);
+  option("specialChars", /[\t\u0000-\u0019\u00ad\u200b-\u200f\u2028\u2029\ufeff]/g, function(cm, val, old) {
+    cm.state.specialChars = new RegExp(val.source + (val.test("\t") ? "" : "|\t"), "g");
+    if (old != CodeMirror.Init) cm.refresh();
+  });
+  option("specialCharPlaceholder", defaultSpecialCharPlaceholder, function(cm) {cm.refresh();}, true);
+  option("electricChars", true);
+  option("inputStyle", mobile ? "contenteditable" : "textarea", function() {
+    throw new Error("inputStyle can not (yet) be changed in a running editor"); // FIXME
+  }, true);
+  option("rtlMoveVisually", !windows);
+  option("wholeLineUpdateBefore", true);
+
+  option("theme", "default", function(cm) {
+    themeChanged(cm);
+    guttersChanged(cm);
+  }, true);
+  option("keyMap", "default", function(cm, val, old) {
+    var next = getKeyMap(val);
+    var prev = old != CodeMirror.Init && getKeyMap(old);
+    if (prev && prev.detach) prev.detach(cm, next);
+    if (next.attach) next.attach(cm, prev || null);
+  });
+  option("extraKeys", null);
+
+  option("lineWrapping", false, wrappingChanged, true);
+  option("gutters", [], function(cm) {
+    setGuttersForLineNumbers(cm.options);
+    guttersChanged(cm);
+  }, true);
+  option("fixedGutter", true, function(cm, val) {
+    cm.display.gutters.style.left = val ? compensateForHScroll(cm.display) + "px" : "0";
+    cm.refresh();
+  }, true);
+  option("coverGutterNextToScrollbar", false, function(cm) {updateScrollbars(cm);}, true);
+  option("scrollbarStyle", "native", function(cm) {
+    initScrollbars(cm);
+    updateScrollbars(cm);
+    cm.display.scrollbars.setScrollTop(cm.doc.scrollTop);
+    cm.display.scrollbars.setScrollLeft(cm.doc.scrollLeft);
+  }, true);
+  option("lineNumbers", false, function(cm) {
+    setGuttersForLineNumbers(cm.options);
+    guttersChanged(cm);
+  }, true);
+  option("firstLineNumber", 1, guttersChanged, true);
+  option("lineNumberFormatter", function(integer) {return integer;}, guttersChanged, true);
+  option("showCursorWhenSelecting", false, updateSelection, true);
+
+  option("resetSelectionOnContextMenu", true);
+  option("lineWiseCopyCut", true);
+
+  option("readOnly", false, function(cm, val) {
+    if (val == "nocursor") {
+      onBlur(cm);
+      cm.display.input.blur();
+      cm.display.disabled = true;
+    } else {
+      cm.display.disabled = false;
+      if (!val) cm.display.input.reset();
+    }
+  });
+  option("disableInput", false, function(cm, val) {if (!val) cm.display.input.reset();}, true);
+  option("dragDrop", true, dragDropChanged);
+
+  option("cursorBlinkRate", 530);
+  option("cursorScrollMargin", 0);
+  option("cursorHeight", 1, updateSelection, true);
+  option("singleCursorHeightPerLine", true, updateSelection, true);
+  option("workTime", 100);
+  option("workDelay", 100);
+  option("flattenSpans", true, resetModeState, true);
+  option("addModeClass", false, resetModeState, true);
+  option("pollInterval", 100);
+  option("undoDepth", 200, function(cm, val){cm.doc.history.undoDepth = val;});
+  option("historyEventDelay", 1250);
+  option("viewportMargin", 10, function(cm){cm.refresh();}, true);
+  option("maxHighlightLength", 10000, resetModeState, true);
+  option("moveInputWithCursor", true, function(cm, val) {
+    if (!val) cm.display.input.resetPosition();
+  });
+
+  option("tabindex", null, function(cm, val) {
+    cm.display.input.getField().tabIndex = val || "";
+  });
+  option("autofocus", null);
+
+  // MODE DEFINITION AND QUERYING
+
+  // Known modes, by name and by MIME
+  var modes = CodeMirror.modes = {}, mimeModes = CodeMirror.mimeModes = {};
+
+  // Extra arguments are stored as the mode's dependencies, which is
+  // used by (legacy) mechanisms like loadmode.js to automatically
+  // load a mode. (Preferred mechanism is the require/define calls.)
+  CodeMirror.defineMode = function(name, mode) {
+    if (!CodeMirror.defaults.mode && name != "null") CodeMirror.defaults.mode = name;
+    if (arguments.length > 2)
+      mode.dependencies = Array.prototype.slice.call(arguments, 2);
+    modes[name] = mode;
+  };
+
+  CodeMirror.defineMIME = function(mime, spec) {
+    mimeModes[mime] = spec;
+  };
+
+  // Given a MIME type, a {name, ...options} config object, or a name
+  // string, return a mode config object.
+  CodeMirror.resolveMode = function(spec) {
+    if (typeof spec == "string" && mimeModes.hasOwnProperty(spec)) {
+      spec = mimeModes[spec];
+    } else if (spec && typeof spec.name == "string" && mimeModes.hasOwnProperty(spec.name)) {
+      var found = mimeModes[spec.name];
+      if (typeof found == "string") found = {name: found};
+      spec = createObj(found, spec);
+      spec.name = found.name;
+    } else if (typeof spec == "string" && /^[\w\-]+\/[\w\-]+\+xml$/.test(spec)) {
+      return CodeMirror.resolveMode("application/xml");
+    }
+    if (typeof spec == "string") return {name: spec};
+    else return spec || {name: "null"};
+  };
+
+  // Given a mode spec (anything that resolveMode accepts), find and
+  // initialize an actual mode object.
+  CodeMirror.getMode = function(options, spec) {
+    var spec = CodeMirror.resolveMode(spec);
+    var mfactory = modes[spec.name];
+    if (!mfactory) return CodeMirror.getMode(options, "text/plain");
+    var modeObj = mfactory(options, spec);
+    if (modeExtensions.hasOwnProperty(spec.name)) {
+      var exts = modeExtensions[spec.name];
+      for (var prop in exts) {
+        if (!exts.hasOwnProperty(prop)) continue;
+        if (modeObj.hasOwnProperty(prop)) modeObj["_" + prop] = modeObj[prop];
+        modeObj[prop] = exts[prop];
+      }
+    }
+    modeObj.name = spec.name;
+    if (spec.helperType) modeObj.helperType = spec.helperType;
+    if (spec.modeProps) for (var prop in spec.modeProps)
+      modeObj[prop] = spec.modeProps[prop];
+
+    return modeObj;
+  };
+
+  // Minimal default mode.
+  CodeMirror.defineMode("null", function() {
+    return {token: function(stream) {stream.skipToEnd();}};
+  });
+  CodeMirror.defineMIME("text/plain", "null");
+
+  // This can be used to attach properties to mode objects from
+  // outside the actual mode definition.
+  var modeExtensions = CodeMirror.modeExtensions = {};
+  CodeMirror.extendMode = function(mode, properties) {
+    var exts = modeExtensions.hasOwnProperty(mode) ? modeExtensions[mode] : (modeExtensions[mode] = {});
+    copyObj(properties, exts);
+  };
+
+  // EXTENSIONS
+
+  CodeMirror.defineExtension = function(name, func) {
+    CodeMirror.prototype[name] = func;
+  };
+  CodeMirror.defineDocExtension = function(name, func) {
+    Doc.prototype[name] = func;
+  };
+  CodeMirror.defineOption = option;
+
+  var initHooks = [];
+  CodeMirror.defineInitHook = function(f) {initHooks.push(f);};
+
+  var helpers = CodeMirror.helpers = {};
+  CodeMirror.registerHelper = function(type, name, value) {
+    if (!helpers.hasOwnProperty(type)) helpers[type] = CodeMirror[type] = {_global: []};
+    helpers[type][name] = value;
+  };
+  CodeMirror.registerGlobalHelper = function(type, name, predicate, value) {
+    CodeMirror.registerHelper(type, name, value);
+    helpers[type]._global.push({pred: predicate, val: value});
+  };
+
+  // MODE STATE HANDLING
+
+  // Utility functions for working with state. Exported because nested
+  // modes need to do this for their inner modes.
+
+  var copyState = CodeMirror.copyState = function(mode, state) {
+    if (state === true) return state;
+    if (mode.copyState) return mode.copyState(state);
+    var nstate = {};
+    for (var n in state) {
+      var val = state[n];
+      if (val instanceof Array) val = val.concat([]);
+      nstate[n] = val;
+    }
+    return nstate;
+  };
+
+  var startState = CodeMirror.startState = function(mode, a1, a2) {
+    return mode.startState ? mode.startState(a1, a2) : true;
+  };
+
+  // Given a mode and a state (for that mode), find the inner mode and
+  // state at the position that the state refers to.
+  CodeMirror.innerMode = function(mode, state) {
+    while (mode.innerMode) {
+      var info = mode.innerMode(state);
+      if (!info || info.mode == mode) break;
+      state = info.state;
+      mode = info.mode;
+    }
+    return info || {mode: mode, state: state};
+  };
+
+  // STANDARD COMMANDS
+
+  // Commands are parameter-less actions that can be performed on an
+  // editor, mostly used for keybindings.
+  var commands = CodeMirror.commands = {
+    selectAll: function(cm) {cm.setSelection(Pos(cm.firstLine(), 0), Pos(cm.lastLine()), sel_dontScroll);},
+    singleSelection: function(cm) {
+      cm.setSelection(cm.getCursor("anchor"), cm.getCursor("head"), sel_dontScroll);
+    },
+    killLine: function(cm) {
+      deleteNearSelection(cm, function(range) {
+        if (range.empty()) {
+          var len = getLine(cm.doc, range.head.line).text.length;
+          if (range.head.ch == len && range.head.line < cm.lastLine())
+            return {from: range.head, to: Pos(range.head.line + 1, 0)};
+          else
+            return {from: range.head, to: Pos(range.head.line, len)};
+        } else {
+          return {from: range.from(), to: range.to()};
+        }
+      });
+    },
+    deleteLine: function(cm) {
+      deleteNearSelection(cm, function(range) {
+        return {from: Pos(range.from().line, 0),
+                to: clipPos(cm.doc, Pos(range.to().line + 1, 0))};
+      });
+    },
+    delLineLeft: function(cm) {
+      deleteNearSelection(cm, function(range) {
+        return {from: Pos(range.from().line, 0), to: range.from()};
+      });
+    },
+    delWrappedLineLeft: function(cm) {
+      deleteNearSelection(cm, function(range) {
+        var top = cm.charCoords(range.head, "div").top + 5;
+        var leftPos = cm.coordsChar({left: 0, top: top}, "div");
+        return {from: leftPos, to: range.from()};
+      });
+    },
+    delWrappedLineRight: function(cm) {
+      deleteNearSelection(cm, function(range) {
+        var top = cm.charCoords(range.head, "div").top + 5;
+        var rightPos = cm.coordsChar({left: cm.display.lineDiv.offsetWidth + 100, top: top}, "div");
+        return {from: range.from(), to: rightPos };
+      });
+    },
+    undo: function(cm) {cm.undo();},
+    redo: function(cm) {cm.redo();},
+    undoSelection: function(cm) {cm.undoSelection();},
+    redoSelection: function(cm) {cm.redoSelection();},
+    goDocStart: function(cm) {cm.extendSelection(Pos(cm.firstLine(), 0));},
+    goDocEnd: function(cm) {cm.extendSelection(Pos(cm.lastLine()));},
+    goLineStart: function(cm) {
+      cm.extendSelectionsBy(function(range) { return lineStart(cm, range.head.line); },
+                            {origin: "+move", bias: 1});
+    },
+    goLineStartSmart: function(cm) {
+      cm.extendSelectionsBy(function(range) {
+        return lineStartSmart(cm, range.head);
+      }, {origin: "+move", bias: 1});
+    },
+    goLineEnd: function(cm) {
+      cm.extendSelectionsBy(function(range) { return lineEnd(cm, range.head.line); },
+                            {origin: "+move", bias: -1});
+    },
+    goLineRight: function(cm) {
+      cm.extendSelectionsBy(function(range) {
+        var top = cm.charCoords(range.head, "div").top + 5;
+        return cm.coordsChar({left: cm.display.lineDiv.offsetWidth + 100, top: top}, "div");
+      }, sel_move);
+    },
+    goLineLeft: function(cm) {
+      cm.extendSelectionsBy(function(range) {
+        var top = cm.charCoords(range.head, "div").top + 5;
+        return cm.coordsChar({left: 0, top: top}, "div");
+      }, sel_move);
+    },
+    goLineLeftSmart: function(cm) {
+      cm.extendSelectionsBy(function(range) {
+        var top = cm.charCoords(range.head, "div").top + 5;
+        var pos = cm.coordsChar({left: 0, top: top}, "div");
+        if (pos.ch < cm.getLine(pos.line).search(/\S/)) return lineStartSmart(cm, range.head);
+        return pos;
+      }, sel_move);
+    },
+    goLineUp: function(cm) {cm.moveV(-1, "line");},
+    goLineDown: function(cm) {cm.moveV(1, "line");},
+    goPageUp: function(cm) {cm.moveV(-1, "page");},
+    goPageDown: function(cm) {cm.moveV(1, "page");},
+    goCharLeft: function(cm) {cm.moveH(-1, "char");},
+    goCharRight: function(cm) {cm.moveH(1, "char");},
+    goColumnLeft: function(cm) {cm.moveH(-1, "column");},
+    goColumnRight: function(cm) {cm.moveH(1, "column");},
+    goWordLeft: function(cm) {cm.moveH(-1, "word");},
+    goGroupRight: function(cm) {cm.moveH(1, "group");},
+    goGroupLeft: function(cm) {cm.moveH(-1, "group");},
+    goWordRight: function(cm) {cm.moveH(1, "word");},
+    delCharBefore: function(cm) {cm.deleteH(-1, "char");},
+    delCharAfter: function(cm) {cm.deleteH(1, "char");},
+    delWordBefore: function(cm) {cm.deleteH(-1, "word");},
+    delWordAfter: function(cm) {cm.deleteH(1, "word");},
+    delGroupBefore: function(cm) {cm.deleteH(-1, "group");},
+    delGroupAfter: function(cm) {cm.deleteH(1, "group");},
+    indentAuto: function(cm) {cm.indentSelection("smart");},
+    indentMore: function(cm) {cm.indentSelection("add");},
+    indentLess: function(cm) {cm.indentSelection("subtract");},
+    insertTab: function(cm) {cm.replaceSelection("\t");},
+    insertSoftTab: function(cm) {
+      var spaces = [], ranges = cm.listSelections(), tabSize = cm.options.tabSize;
+      for (var i = 0; i < ranges.length; i++) {
+        var pos = ranges[i].from();
+        var col = countColumn(cm.getLine(pos.line), pos.ch, tabSize);
+        spaces.push(new Array(tabSize - col % tabSize + 1).join(" "));
+      }
+      cm.replaceSelections(spaces);
+    },
+    defaultTab: function(cm) {
+      if (cm.somethingSelected()) cm.indentSelection("add");
+      else cm.execCommand("insertTab");
+    },
+    transposeChars: function(cm) {
+      runInOp(cm, function() {
+        var ranges = cm.listSelections(), newSel = [];
+        for (var i = 0; i < ranges.length; i++) {
+          var cur = ranges[i].head, line = getLine(cm.doc, cur.line).text;
+          if (line) {
+            if (cur.ch == line.length) cur = new Pos(cur.line, cur.ch - 1);
+            if (cur.ch > 0) {
+              cur = new Pos(cur.line, cur.ch + 1);
+              cm.replaceRange(line.charAt(cur.ch - 1) + line.charAt(cur.ch - 2),
+                              Pos(cur.line, cur.ch - 2), cur, "+transpose");
+            } else if (cur.line > cm.doc.first) {
+              var prev = getLine(cm.doc, cur.line - 1).text;
+              if (prev)
+                cm.replaceRange(line.charAt(0) + "\n" + prev.charAt(prev.length - 1),
+                                Pos(cur.line - 1, prev.length - 1), Pos(cur.line, 1), "+transpose");
+            }
+          }
+          newSel.push(new Range(cur, cur));
+        }
+        cm.setSelections(newSel);
+      });
+    },
+    newlineAndIndent: function(cm) {
+      runInOp(cm, function() {
+        var len = cm.listSelections().length;
+        for (var i = 0; i < len; i++) {
+          var range = cm.listSelections()[i];
+          cm.replaceRange("\n", range.anchor, range.head, "+input");
+          cm.indentLine(range.from().line + 1, null, true);
+          ensureCursorVisible(cm);
+        }
+      });
+    },
+    toggleOverwrite: function(cm) {cm.toggleOverwrite();}
+  };
+
+
+  // STANDARD KEYMAPS
+
+  var keyMap = CodeMirror.keyMap = {};
+
+  keyMap.basic = {
+    "Left": "goCharLeft", "Right": "goCharRight", "Up": "goLineUp", "Down": "goLineDown",
+    "End": "goLineEnd", "Home": "goLineStartSmart", "PageUp": "goPageUp", "PageDown": "goPageDown",
+    "Delete": "delCharAfter", "Backspace": "delCharBefore", "Shift-Backspace": "delCharBefore",
+    "Tab": "defaultTab", "Shift-Tab": "indentAuto",
+    "Enter": "newlineAndIndent", "Insert": "toggleOverwrite",
+    "Esc": "singleSelection"
+  };
+  // Note that the save and find-related commands aren't defined by
+  // default. User code or addons can define them. Unknown commands
+  // are simply ignored.
+  keyMap.pcDefault = {
+    "Ctrl-A": "selectAll", "Ctrl-D": "deleteLine", "Ctrl-Z": "undo", "Shift-Ctrl-Z": "redo", "Ctrl-Y": "redo",
+    "Ctrl-Home": "goDocStart", "Ctrl-End": "goDocEnd", "Ctrl-Up": "goLineUp", "Ctrl-Down": "goLineDown",
+    "Ctrl-Left": "goGroupLeft", "Ctrl-Right": "goGroupRight", "Alt-Left": "goLineStart", "Alt-Right": "goLineEnd",
+    "Ctrl-Backspace": "delGroupBefore", "Ctrl-Delete": "delGroupAfter", "Ctrl-S": "save", "Ctrl-F": "find",
+    "Ctrl-G": "findNext", "Shift-Ctrl-G": "findPrev", "Shift-Ctrl-F": "replace", "Shift-Ctrl-R": "replaceAll",
+    "Ctrl-[": "indentLess", "Ctrl-]": "indentMore",
+    "Ctrl-U": "undoSelection", "Shift-Ctrl-U": "redoSelection", "Alt-U": "redoSelection",
+    fallthrough: "basic"
+  };
+  // Very basic readline/emacs-style bindings, which are standard on Mac.
+  keyMap.emacsy = {
+    "Ctrl-F": "goCharRight", "Ctrl-B": "goCharLeft", "Ctrl-P": "goLineUp", "Ctrl-N": "goLineDown",
+    "Alt-F": "goWordRight", "Alt-B": "goWordLeft", "Ctrl-A": "goLineStart", "Ctrl-E": "goLineEnd",
+    "Ctrl-V": "goPageDown", "Shift-Ctrl-V": "goPageUp", "Ctrl-D": "delCharAfter", "Ctrl-H": "delCharBefore",
+    "Alt-D": "delWordAfter", "Alt-Backspace": "delWordBefore", "Ctrl-K": "killLine", "Ctrl-T": "transposeChars"
+  };
+  keyMap.macDefault = {
+    "Cmd-A": "selectAll", "Cmd-D": "deleteLine", "Cmd-Z": "undo", "Shift-Cmd-Z": "redo", "Cmd-Y": "redo",
+    "Cmd-Home": "goDocStart", "Cmd-Up": "goDocStart", "Cmd-End": "goDocEnd", "Cmd-Down": "goDocEnd", "Alt-Left": "goGroupLeft",
+    "Alt-Right": "goGroupRight", "Cmd-Left": "goLineLeft", "Cmd-Right": "goLineRight", "Alt-Backspace": "delGroupBefore",
+    "Ctrl-Alt-Backspace": "delGroupAfter", "Alt-Delete": "delGroupAfter", "Cmd-S": "save", "Cmd-F": "find",
+    "Cmd-G": "findNext", "Shift-Cmd-G": "findPrev", "Cmd-Alt-F": "replace", "Shift-Cmd-Alt-F": "replaceAll",
+    "Cmd-[": "indentLess", "Cmd-]": "indentMore", "Cmd-Backspace": "delWrappedLineLeft", "Cmd-Delete": "delWrappedLineRight",
+    "Cmd-U": "undoSelection", "Shift-Cmd-U": "redoSelection", "Ctrl-Up": "goDocStart", "Ctrl-Down": "goDocEnd",
+    fallthrough: ["basic", "emacsy"]
+  };
+  keyMap["default"] = mac ? keyMap.macDefault : keyMap.pcDefault;
+
+  // KEYMAP DISPATCH
+
+  function normalizeKeyName(name) {
+    var parts = name.split(/-(?!$)/), name = parts[parts.length - 1];
+    var alt, ctrl, shift, cmd;
+    for (var i = 0; i < parts.length - 1; i++) {
+      var mod = parts[i];
+      if (/^(cmd|meta|m)$/i.test(mod)) cmd = true;
+      else if (/^a(lt)?$/i.test(mod)) alt = true;
+      else if (/^(c|ctrl|control)$/i.test(mod)) ctrl = true;
+      else if (/^s(hift)$/i.test(mod)) shift = true;
+      else throw new Error("Unrecognized modifier name: " + mod);
+    }
+    if (alt) name = "Alt-" + name;
+    if (ctrl) name = "Ctrl-" + name;
+    if (cmd) name = "Cmd-" + name;
+    if (shift) name = "Shift-" + name;
+    return name;
+  }
+
+  // This is a kludge to keep keymaps mostly working as raw objects
+  // (backwards compatibility) while at the same time support features
+  // like normalization and multi-stroke key bindings. It compiles a
+  // new normalized keymap, and then updates the old object to reflect
+  // this.
+  CodeMirror.normalizeKeyMap = function(keymap) {
+    var copy = {};
+    for (var keyname in keymap) if (keymap.hasOwnProperty(keyname)) {
+      var value = keymap[keyname];
+      if (/^(name|fallthrough|(de|at)tach)$/.test(keyname)) continue;
+      if (value == "...") { delete keymap[keyname]; continue; }
+
+      var keys = map(keyname.split(" "), normalizeKeyName);
+      for (var i = 0; i < keys.length; i++) {
+        var val, name;
+        if (i == keys.length - 1) {
+          name = keys.join(" ");
+          val = value;
+        } else {
+          name = keys.slice(0, i + 1).join(" ");
+          val = "...";
+        }
+        var prev = copy[name];
+        if (!prev) copy[name] = val;
+        else if (prev != val) throw new Error("Inconsistent bindings for " + name);
+      }
+      delete keymap[keyname];
+    }
+    for (var prop in copy) keymap[prop] = copy[prop];
+    return keymap;
+  };
+
+  var lookupKey = CodeMirror.lookupKey = function(key, map, handle, context) {
+    map = getKeyMap(map);
+    var found = map.call ? map.call(key, context) : map[key];
+    if (found === false) return "nothing";
+    if (found === "...") return "multi";
+    if (found != null && handle(found)) return "handled";
+
+    if (map.fallthrough) {
+      if (Object.prototype.toString.call(map.fallthrough) != "[object Array]")
+        return lookupKey(key, map.fallthrough, handle, context);
+      for (var i = 0; i < map.fallthrough.length; i++) {
+        var result = lookupKey(key, map.fallthrough[i], handle, context);
+        if (result) return result;
+      }
+    }
+  };
+
+  // Modifier key presses don't count as 'real' key presses for the
+  // purpose of keymap fallthrough.
+  var isModifierKey = CodeMirror.isModifierKey = function(value) {
+    var name = typeof value == "string" ? value : keyNames[value.keyCode];
+    return name == "Ctrl" || name == "Alt" || name == "Shift" || name == "Mod";
+  };
+
+  // Look up the name of a key as indicated by an event object.
+  var keyName = CodeMirror.keyName = function(event, noShift) {
+    if (presto && event.keyCode == 34 && event["char"]) return false;
+    var base = keyNames[event.keyCode], name = base;
+    if (name == null || event.altGraphKey) return false;
+    if (event.altKey && base != "Alt") name = "Alt-" + name;
+    if ((flipCtrlCmd ? event.metaKey : event.ctrlKey) && base != "Ctrl") name = "Ctrl-" + name;
+    if ((flipCtrlCmd ? event.ctrlKey : event.metaKey) && base != "Cmd") name = "Cmd-" + name;
+    if (!noShift && event.shiftKey && base != "Shift") name = "Shift-" + name;
+    return name;
+  };
+
+  function getKeyMap(val) {
+    return typeof val == "string" ? keyMap[val] : val;
+  }
+
+  // FROMTEXTAREA
+
+  CodeMirror.fromTextArea = function(textarea, options) {
+    options = options ? copyObj(options) : {};
+    options.value = textarea.value;
+    if (!options.tabindex && textarea.tabIndex)
+      options.tabindex = textarea.tabIndex;
+    if (!options.placeholder && textarea.placeholder)
+      options.placeholder = textarea.placeholder;
+    // Set autofocus to true if this textarea is focused, or if it has
+    // autofocus and no other element is focused.
+    if (options.autofocus == null) {
+      var hasFocus = activeElt();
+      options.autofocus = hasFocus == textarea ||
+        textarea.getAttribute("autofocus") != null && hasFocus == document.body;
+    }
+
+    function save() {textarea.value = cm.getValue();}
+    if (textarea.form) {
+      on(textarea.form, "submit", save);
+      // Deplorable hack to make the submit method do the right thing.
+      if (!options.leaveSubmitMethodAlone) {
+        var form = textarea.form, realSubmit = form.submit;
+        try {
+          var wrappedSubmit = form.submit = function() {
+            save();
+            form.submit = realSubmit;
+            form.submit();
+            form.submit = wrappedSubmit;
+          };
+        } catch(e) {}
+      }
+    }
+
+    options.finishInit = function(cm) {
+      cm.save = save;
+      cm.getTextArea = function() { return textarea; };
+      cm.toTextArea = function() {
+        cm.toTextArea = isNaN; // Prevent this from being ran twice
+        save();
+        textarea.parentNode.removeChild(cm.getWrapperElement());
+        textarea.style.display = "";
+        if (textarea.form) {
+          off(textarea.form, "submit", save);
+          if (typeof textarea.form.submit == "function")
+            textarea.form.submit = realSubmit;
+        }
+      };
+    };
+
+    textarea.style.display = "none";
+    var cm = CodeMirror(function(node) {
+      textarea.parentNode.insertBefore(node, textarea.nextSibling);
+    }, options);
+    return cm;
+  };
+
+  // STRING STREAM
+
+  // Fed to the mode parsers, provides helper functions to make
+  // parsers more succinct.
+
+  var StringStream = CodeMirror.StringStream = function(string, tabSize) {
+    this.pos = this.start = 0;
+    this.string = string;
+    this.tabSize = tabSize || 8;
+    this.lastColumnPos = this.lastColumnValue = 0;
+    this.lineStart = 0;
+  };
+
+  StringStream.prototype = {
+    eol: function() {return this.pos >= this.string.length;},
+    sol: function() {return this.pos == this.lineStart;},
+    peek: function() {return this.string.charAt(this.pos) || undefined;},
+    next: function() {
+      if (this.pos < this.string.length)
+        return this.string.charAt(this.pos++);
+    },
+    eat: function(match) {
+      var ch = this.string.charAt(this.pos);
+      if (typeof match == "string") var ok = ch == match;
+      else var ok = ch && (match.test ? match.test(ch) : match(ch));
+      if (ok) {++this.pos; return ch;}
+    },
+    eatWhile: function(match) {
+      var start = this.pos;
+      while (this.eat(match)){}
+      return this.pos > start;
+    },
+    eatSpace: function() {
+      var start = this.pos;
+      while (/[\s\u00a0]/.test(this.string.charAt(this.pos))) ++this.pos;
+      return this.pos > start;
+    },
+    skipToEnd: function() {this.pos = this.string.length;},
+    skipTo: function(ch) {
+      var found = this.string.indexOf(ch, this.pos);
+      if (found > -1) {this.pos = found; return true;}
+    },
+    backUp: function(n) {this.pos -= n;},
+    column: function() {
+      if (this.lastColumnPos < this.start) {
+        this.lastColumnValue = countColumn(this.string, this.start, this.tabSize, this.lastColumnPos, this.lastColumnValue);
+        this.lastColumnPos = this.start;
+      }
+      return this.lastColumnValue - (this.lineStart ? countColumn(this.string, this.lineStart, this.tabSize) : 0);
+    },
+    indentation: function() {
+      return countColumn(this.string, null, this.tabSize) -
+        (this.lineStart ? countColumn(this.string, this.lineStart, this.tabSize) : 0);
+    },
+    match: function(pattern, consume, caseInsensitive) {
+      if (typeof pattern == "string") {
+        var cased = function(str) {return caseInsensitive ? str.toLowerCase() : str;};
+        var substr = this.string.substr(this.pos, pattern.length);
+        if (cased(substr) == cased(pattern)) {
+          if (consume !== false) this.pos += pattern.length;
+          return true;
+        }
+      } else {
+        var match = this.string.slice(this.pos).match(pattern);
+        if (match && match.index > 0) return null;
+        if (match && consume !== false) this.pos += match[0].length;
+        return match;
+      }
+    },
+    current: function(){return this.string.slice(this.start, this.pos);},
+    hideFirstChars: function(n, inner) {
+      this.lineStart += n;
+      try { return inner(); }
+      finally { this.lineStart -= n; }
+    }
+  };
+
+  // TEXTMARKERS
+
+  // Created with markText and setBookmark methods. A TextMarker is a
+  // handle that can be used to clear or find a marked position in the
+  // document. Line objects hold arrays (markedSpans) containing
+  // {from, to, marker} object pointing to such marker objects, and
+  // indicating that such a marker is present on that line. Multiple
+  // lines may point to the same marker when it spans across lines.
+  // The spans will have null for their from/to properties when the
+  // marker continues beyond the start/end of the line. Markers have
+  // links back to the lines they currently touch.
+
+  var nextMarkerId = 0;
+
+  var TextMarker = CodeMirror.TextMarker = function(doc, type) {
+    this.lines = [];
+    this.type = type;
+    this.doc = doc;
+    this.id = ++nextMarkerId;
+  };
+  eventMixin(TextMarker);
+
+  // Clear the marker.
+  TextMarker.prototype.clear = function() {
+    if (this.explicitlyCleared) return;
+    var cm = this.doc.cm, withOp = cm && !cm.curOp;
+    if (withOp) startOperation(cm);
+    if (hasHandler(this, "clear")) {
+      var found = this.find();
+      if (found) signalLater(this, "clear", found.from, found.to);
+    }
+    var min = null, max = null;
+    for (var i = 0; i < this.lines.length; ++i) {
+      var line = this.lines[i];
+      var span = getMarkedSpanFor(line.markedSpans, this);
+      if (cm && !this.collapsed) regLineChange(cm, lineNo(line), "text");
+      else if (cm) {
+        if (span.to != null) max = lineNo(line);
+        if (span.from != null) min = lineNo(line);
+      }
+      line.markedSpans = removeMarkedSpan(line.markedSpans, span);
+      if (span.from == null && this.collapsed && !lineIsHidden(this.doc, line) && cm)
+        updateLineHeight(line, textHeight(cm.display));
+    }
+    if (cm && this.collapsed && !cm.options.lineWrapping) for (var i = 0; i < this.lines.length; ++i) {
+      var visual = visualLine(this.lines[i]), len = lineLength(visual);
+      if (len > cm.display.maxLineLength) {
+        cm.display.maxLine = visual;
+        cm.display.maxLineLength = len;
+        cm.display.maxLineChanged = true;
+      }
+    }
+
+    if (min != null && cm && this.collapsed) regChange(cm, min, max + 1);
+    this.lines.length = 0;
+    this.explicitlyCleared = true;
+    if (this.atomic && this.doc.cantEdit) {
+      this.doc.cantEdit = false;
+      if (cm) reCheckSelection(cm.doc);
+    }
+    if (cm) signalLater(cm, "markerCleared", cm, this);
+    if (withOp) endOperation(cm);
+    if (this.parent) this.parent.clear();
+  };
+
+  // Find the position of the marker in the document. Returns a {from,
+  // to} object by default. Side can be passed to get a specific side
+  // -- 0 (both), -1 (left), or 1 (right). When lineObj is true, the
+  // Pos objects returned contain a line object, rather than a line
+  // number (used to prevent looking up the same line twice).
+  TextMarker.prototype.find = function(side, lineObj) {
+    if (side == null && this.type == "bookmark") side = 1;
+    var from, to;
+    for (var i = 0; i < this.lines.length; ++i) {
+      var line = this.lines[i];
+      var span = getMarkedSpanFor(line.markedSpans, this);
+      if (span.from != null) {
+        from = Pos(lineObj ? line : lineNo(line), span.from);
+        if (side == -1) return from;
+      }
+      if (span.to != null) {
+        to = Pos(lineObj ? line : lineNo(line), span.to);
+        if (side == 1) return to;
+      }
+    }
+    return from && {from: from, to: to};
+  };
+
+  // Signals that the marker's widget changed, and surrounding layout
+  // should be recomputed.
+  TextMarker.prototype.changed = function() {
+    var pos = this.find(-1, true), widget = this, cm = this.doc.cm;
+    if (!pos || !cm) return;
+    runInOp(cm, function() {
+      var line = pos.line, lineN = lineNo(pos.line);
+      var view = findViewForLine(cm, lineN);
+      if (view) {
+        clearLineMeasurementCacheFor(view);
+        cm.curOp.selectionChanged = cm.curOp.forceUpdate = true;
+      }
+      cm.curOp.updateMaxLine = true;
+      if (!lineIsHidden(widget.doc, line) && widget.height != null) {
+        var oldHeight = widget.height;
+        widget.height = null;
+        var dHeight = widgetHeight(widget) - oldHeight;
+        if (dHeight)
+          updateLineHeight(line, line.height + dHeight);
+      }
+    });
+  };
+
+  TextMarker.prototype.attachLine = function(line) {
+    if (!this.lines.length && this.doc.cm) {
+      var op = this.doc.cm.curOp;
+      if (!op.maybeHiddenMarkers || indexOf(op.maybeHiddenMarkers, this) == -1)
+        (op.maybeUnhiddenMarkers || (op.maybeUnhiddenMarkers = [])).push(this);
+    }
+    this.lines.push(line);
+  };
+  TextMarker.prototype.detachLine = function(line) {
+    this.lines.splice(indexOf(this.lines, line), 1);
+    if (!this.lines.length && this.doc.cm) {
+      var op = this.doc.cm.curOp;
+      (op.maybeHiddenMarkers || (op.maybeHiddenMarkers = [])).push(this);
+    }
+  };
+
+  // Collapsed markers have unique ids, in order to be able to order
+  // them, which is needed for uniquely determining an outer marker
+  // when they overlap (they may nest, but not partially overlap).
+  var nextMarkerId = 0;
+
+  // Create a marker, wire it up to the right lines, and
+  function markText(doc, from, to, options, type) {
+    // Shared markers (across linked documents) are handled separately
+    // (markTextShared will call out to this again, once per
+    // document).
+    if (options && options.shared) return markTextShared(doc, from, to, options, type);
+    // Ensure we are in an operation.
+    if (doc.cm && !doc.cm.curOp) return operation(doc.cm, markText)(doc, from, to, options, type);
+
+    var marker = new TextMarker(doc, type), diff = cmp(from, to);
+    if (options) copyObj(options, marker, false);
+    // Don't connect empty markers unless clearWhenEmpty is false
+    if (diff > 0 || diff == 0 && marker.clearWhenEmpty !== false)
+      return marker;
+    if (marker.replacedWith) {
+      // Showing up as a widget implies collapsed (widget replaces text)
+      marker.collapsed = true;
+      marker.widgetNode = elt("span", [marker.replacedWith], "CodeMirror-widget");
+      if (!options.handleMouseEvents) marker.widgetNode.setAttribute("cm-ignore-events", "true");
+      if (options.insertLeft) marker.widgetNode.insertLeft = true;
+    }
+    if (marker.collapsed) {
+      if (conflictingCollapsedRange(doc, from.line, from, to, marker) ||
+          from.line != to.line && conflictingCollapsedRange(doc, to.line, from, to, marker))
+        throw new Error("Inserting collapsed marker partially overlapping an existing one");
+      sawCollapsedSpans = true;
+    }
+
+    if (marker.addToHistory)
+      addChangeToHistory(doc, {from: from, to: to, origin: "markText"}, doc.sel, NaN);
+
+    var curLine = from.line, cm = doc.cm, updateMaxLine;
+    doc.iter(curLine, to.line + 1, function(line) {
+      if (cm && marker.collapsed && !cm.options.lineWrapping && visualLine(line) == cm.display.maxLine)
+        updateMaxLine = true;
+      if (marker.collapsed && curLine != from.line) updateLineHeight(line, 0);
+      addMarkedSpan(line, new MarkedSpan(marker,
+                                         curLine == from.line ? from.ch : null,
+                                         curLine == to.line ? to.ch : null));
+      ++curLine;
+    });
+    // lineIsHidden depends on the presence of the spans, so needs a second pass
+    if (marker.collapsed) doc.iter(from.line, to.line + 1, function(line) {
+      if (lineIsHidden(doc, line)) updateLineHeight(line, 0);
+    });
+
+    if (marker.clearOnEnter) on(marker, "beforeCursorEnter", function() { marker.clear(); });
+
+    if (marker.readOnly) {
+      sawReadOnlySpans = true;
+      if (doc.history.done.length || doc.history.undone.length)
+        doc.clearHistory();
+    }
+    if (marker.collapsed) {
+      marker.id = ++nextMarkerId;
+      marker.atomic = true;
+    }
+    if (cm) {
+      // Sync editor state
+      if (updateMaxLine) cm.curOp.updateMaxLine = true;
+      if (marker.collapsed)
+        regChange(cm, from.line, to.line + 1);
+      else if (marker.className || marker.title || marker.startStyle || marker.endStyle || marker.css)
+        for (var i = from.line; i <= to.line; i++) regLineChange(cm, i, "text");
+      if (marker.atomic) reCheckSelection(cm.doc);
+      signalLater(cm, "markerAdded", cm, marker);
+    }
+    return marker;
+  }
+
+  // SHARED TEXTMARKERS
+
+  // A shared marker spans multiple linked documents. It is
+  // implemented as a meta-marker-object controlling multiple normal
+  // markers.
+  var SharedTextMarker = CodeMirror.SharedTextMarker = function(markers, primary) {
+    this.markers = markers;
+    this.primary = primary;
+    for (var i = 0; i < markers.length; ++i)
+      markers[i].parent = this;
+  };
+  eventMixin(SharedTextMarker);
+
+  SharedTextMarker.prototype.clear = function() {
+    if (this.explicitlyCleared) return;
+    this.explicitlyCleared = true;
+    for (var i = 0; i < this.markers.length; ++i)
+      this.markers[i].clear();
+    signalLater(this, "clear");
+  };
+  SharedTextMarker.prototype.find = function(side, lineObj) {
+    return this.primary.find(side, lineObj);
+  };
+
+  function markTextShared(doc, from, to, options, type) {
+    options = copyObj(options);
+    options.shared = false;
+    var markers = [markText(doc, from, to, options, type)], primary = markers[0];
+    var widget = options.widgetNode;
+    linkedDocs(doc, function(doc) {
+      if (widget) options.widgetNode = widget.cloneNode(true);
+      markers.push(markText(doc, clipPos(doc, from), clipPos(doc, to), options, type));
+      for (var i = 0; i < doc.linked.length; ++i)
+        if (doc.linked[i].isParent) return;
+      primary = lst(markers);
+    });
+    return new SharedTextMarker(markers, primary);
+  }
+
+  function findSharedMarkers(doc) {
+    return doc.findMarks(Pos(doc.first, 0), doc.clipPos(Pos(doc.lastLine())),
+                         function(m) { return m.parent; });
+  }
+
+  function copySharedMarkers(doc, markers) {
+    for (var i = 0; i < markers.length; i++) {
+      var marker = markers[i], pos = marker.find();
+      var mFrom = doc.clipPos(pos.from), mTo = doc.clipPos(pos.to);
+      if (cmp(mFrom, mTo)) {
+        var subMark = markText(doc, mFrom, mTo, marker.primary, marker.primary.type);
+        marker.markers.push(subMark);
+        subMark.parent = marker;
+      }
+    }
+  }
+
+  function detachSharedMarkers(markers) {
+    for (var i = 0; i < markers.length; i++) {
+      var marker = markers[i], linked = [marker.primary.doc];;
+      linkedDocs(marker.primary.doc, function(d) { linked.push(d); });
+      for (var j = 0; j < marker.markers.length; j++) {
+        var subMarker = marker.markers[j];
+        if (indexOf(linked, subMarker.doc) == -1) {
+          subMarker.parent = null;
+          marker.markers.splice(j--, 1);
+        }
+      }
+    }
+  }
+
+  // TEXTMARKER SPANS
+
+  function MarkedSpan(marker, from, to) {
+    this.marker = marker;
+    this.from = from; this.to = to;
+  }
+
+  // Search an array of spans for a span matching the given marker.
+  function getMarkedSpanFor(spans, marker) {
+    if (spans) for (var i = 0; i < spans.length; ++i) {
+      var span = spans[i];
+      if (span.marker == marker) return span;
+    }
+  }
+  // Remove a span from an array, returning undefined if no spans are
+  // left (we don't store arrays for lines without spans).
+  function removeMarkedSpan(spans, span) {
+    for (var r, i = 0; i < spans.length; ++i)
+      if (spans[i] != span) (r || (r = [])).push(spans[i]);
+    return r;
+  }
+  // Add a span to a line.
+  function addMarkedSpan(line, span) {
+    line.markedSpans = line.markedSpans ? line.markedSpans.concat([span]) : [span];
+    span.marker.attachLine(line);
+  }
+
+  // Used for the algorithm that adjusts markers for a change in the
+  // document. These functions cut an array of spans at a given
+  // character position, returning an array of remaining chunks (or
+  // undefined if nothing remains).
+  function markedSpansBefore(old, startCh, isInsert) {
+    if (old) for (var i = 0, nw; i < old.length; ++i) {
+      var span = old[i], marker = span.marker;
+      var startsBefore = span.from == null || (marker.inclusiveLeft ? span.from <= startCh : span.from < startCh);
+      if (startsBefore || span.from == startCh && marker.type == "bookmark" && (!isInsert || !span.marker.insertLeft)) {
+        var endsAfter = span.to == null || (marker.inclusiveRight ? span.to >= startCh : span.to > startCh);
+        (nw || (nw = [])).push(new MarkedSpan(marker, span.from, endsAfter ? null : span.to));
+      }
+    }
+    return nw;
+  }
+  function markedSpansAfter(old, endCh, isInsert) {
+    if (old) for (var i = 0, nw; i < old.length; ++i) {
+      var span = old[i], marker = span.marker;
+      var endsAfter = span.to == null || (marker.inclusiveRight ? span.to >= endCh : span.to > endCh);
+      if (endsAfter || span.from == endCh && marker.type == "bookmark" && (!isInsert || span.marker.insertLeft)) {
+        var startsBefore = span.from == null || (marker.inclusiveLeft ? span.from <= endCh : span.from < endCh);
+        (nw || (nw = [])).push(new MarkedSpan(marker, startsBefore ? null : span.from - endCh,
+                                              span.to == null ? null : span.to - endCh));
+      }
+    }
+    return nw;
+  }
+
+  // Given a change object, compute the new set of marker spans that
+  // cover the line in which the change took place. Removes spans
+  // entirely within the change, reconnects spans belonging to the
+  // same marker that appear on both sides of the change, and cuts off
+  // spans partially within the change. Returns an array of span
+  // arrays with one element for each line in (after) the change.
+  function stretchSpansOverChange(doc, change) {
+    if (change.full) return null;
+    var oldFirst = isLine(doc, change.from.line) && getLine(doc, change.from.line).markedSpans;
+    var oldLast = isLine(doc, change.to.line) && getLine(doc, change.to.line).markedSpans;
+    if (!oldFirst && !oldLast) return null;
+
+    var startCh = change.from.ch, endCh = change.to.ch, isInsert = cmp(change.from, change.to) == 0;
+    // Get the spans that 'stick out' on both sides
+    var first = markedSpansBefore(oldFirst, startCh, isInsert);
+    var last = markedSpansAfter(oldLast, endCh, isInsert);
+
+    // Next, merge those two ends
+    var sameLine = change.text.length == 1, offset = lst(change.text).length + (sameLine ? startCh : 0);
+    if (first) {
+      // Fix up .to properties of first
+      for (var i = 0; i < first.length; ++i) {
+        var span = first[i];
+        if (span.to == null) {
+          var found = getMarkedSpanFor(last, span.marker);
+          if (!found) span.to = startCh;
+          else if (sameLine) span.to = found.to == null ? null : found.to + offset;
+        }
+      }
+    }
+    if (last) {
+      // Fix up .from in last (or move them into first in case of sameLine)
+      for (var i = 0; i < last.length; ++i) {
+        var span = last[i];
+        if (span.to != null) span.to += offset;
+        if (span.from == null) {
+          var found = getMarkedSpanFor(first, span.marker);
+          if (!found) {
+            span.from = offset;
+            if (sameLine) (first || (first = [])).push(span);
+          }
+        } else {
+          span.from += offset;
+          if (sameLine) (first || (first = [])).push(span);
+        }
+      }
+    }
+    // Make sure we didn't create any zero-length spans
+    if (first) first = clearEmptySpans(first);
+    if (last && last != first) last = clearEmptySpans(last);
+
+    var newMarkers = [first];
+    if (!sameLine) {
+      // Fill gap with whole-line-spans
+      var gap = change.text.length - 2, gapMarkers;
+      if (gap > 0 && first)
+        for (var i = 0; i < first.length; ++i)
+          if (first[i].to == null)
+            (gapMarkers || (gapMarkers = [])).push(new MarkedSpan(first[i].marker, null, null));
+      for (var i = 0; i < gap; ++i)
+        newMarkers.push(gapMarkers);
+      newMarkers.push(last);
+    }
+    return newMarkers;
+  }
+
+  // Remove spans that are empty and don't have a clearWhenEmpty
+  // option of false.
+  function clearEmptySpans(spans) {
+    for (var i = 0; i < spans.length; ++i) {
+      var span = spans[i];
+      if (span.from != null && span.from == span.to && span.marker.clearWhenEmpty !== false)
+        spans.splice(i--, 1);
+    }
+    if (!spans.length) return null;
+    return spans;
+  }
+
+  // Used for un/re-doing changes from the history. Combines the
+  // result of computing the existing spans with the set of spans that
+  // existed in the history (so that deleting around a span and then
+  // undoing brings back the span).
+  function mergeOldSpans(doc, change) {
+    var old = getOldSpans(doc, change);
+    var stretched = stretchSpansOverChange(doc, change);
+    if (!old) return stretched;
+    if (!stretched) return old;
+
+    for (var i = 0; i < old.length; ++i) {
+      var oldCur = old[i], stretchCur = stretched[i];
+      if (oldCur && stretchCur) {
+        spans: for (var j = 0; j < stretchCur.length; ++j) {
+          var span = stretchCur[j];
+          for (var k = 0; k < oldCur.length; ++k)
+            if (oldCur[k].marker == span.marker) continue spans;
+          oldCur.push(span);
+        }
+      } else if (stretchCur) {
+        old[i] = stretchCur;
+      }
+    }
+    return old;
+  }
+
+  // Used to 'clip' out readOnly ranges when making a change.
+  function removeReadOnlyRanges(doc, from, to) {
+    var markers = null;
+    doc.iter(from.line, to.line + 1, function(line) {
+      if (line.markedSpans) for (var i = 0; i < line.markedSpans.length; ++i) {
+        var mark = line.markedSpans[i].marker;
+        if (mark.readOnly && (!markers || indexOf(markers, mark) == -1))
+          (markers || (markers = [])).push(mark);
+      }
+    });
+    if (!markers) return null;
+    var parts = [{from: from, to: to}];
+    for (var i = 0; i < markers.length; ++i) {
+      var mk = markers[i], m = mk.find(0);
+      for (var j = 0; j < parts.length; ++j) {
+        var p = parts[j];
+        if (cmp(p.to, m.from) < 0 || cmp(p.from, m.to) > 0) continue;
+        var newParts = [j, 1], dfrom = cmp(p.from, m.from), dto = cmp(p.to, m.to);
+        if (dfrom < 0 || !mk.inclusiveLeft && !dfrom)
+          newParts.push({from: p.from, to: m.from});
+        if (dto > 0 || !mk.inclusiveRight && !dto)
+          newParts.push({from: m.to, to: p.to});
+        parts.splice.apply(parts, newParts);
+        j += newParts.length - 1;
+      }
+    }
+    return parts;
+  }
+
+  // Connect or disconnect spans from a line.
+  function detachMarkedSpans(line) {
+    var spans = line.markedSpans;
+    if (!spans) return;
+    for (var i = 0; i < spans.length; ++i)
+      spans[i].marker.detachLine(line);
+    line.markedSpans = null;
+  }
+  function attachMarkedSpans(line, spans) {
+    if (!spans) return;
+    for (var i = 0; i < spans.length; ++i)
+      spans[i].marker.attachLine(line);
+    line.markedSpans = spans;
+  }
+
+  // Helpers used when computing which overlapping collapsed span
+  // counts as the larger one.
+  function extraLeft(marker) { return marker.inclusiveLeft ? -1 : 0; }
+  function extraRight(marker) { return marker.inclusiveRight ? 1 : 0; }
+
+  // Returns a number indicating which of two overlapping collapsed
+  // spans is larger (and thus includes the other). Falls back to
+  // comparing ids when the spans cover exactly the same range.
+  function compareCollapsedMarkers(a, b) {
+    var lenDiff = a.lines.length - b.lines.length;
+    if (lenDiff != 0) return lenDiff;
+    var aPos = a.find(), bPos = b.find();
+    var fromCmp = cmp(aPos.from, bPos.from) || extraLeft(a) - extraLeft(b);
+    if (fromCmp) return -fromCmp;
+    var toCmp = cmp(aPos.to, bPos.to) || extraRight(a) - extraRight(b);
+    if (toCmp) return toCmp;
+    return b.id - a.id;
+  }
+
+  // Find out whether a line ends or starts in a collapsed span. If
+  // so, return the marker for that span.
+  function collapsedSpanAtSide(line, start) {
+    var sps = sawCollapsedSpans && line.markedSpans, found;
+    if (sps) for (var sp, i = 0; i < sps.length; ++i) {
+      sp = sps[i];
+      if (sp.marker.collapsed && (start ? sp.from : sp.to) == null &&
+          (!found || compareCollapsedMarkers(found, sp.marker) < 0))
+        found = sp.marker;
+    }
+    return found;
+  }
+  function collapsedSpanAtStart(line) { return collapsedSpanAtSide(line, true); }
+  function collapsedSpanAtEnd(line) { return collapsedSpanAtSide(line, false); }
+
+  // Test whether there exists a collapsed span that partially
+  // overlaps (covers the start or end, but not both) of a new span.
+  // Such overlap is not allowed.
+  function conflictingCollapsedRange(doc, lineNo, from, to, marker) {
+    var line = getLine(doc, lineNo);
+    var sps = sawCollapsedSpans && line.markedSpans;
+    if (sps) for (var i = 0; i < sps.length; ++i) {
+      var sp = sps[i];
+      if (!sp.marker.collapsed) continue;
+      var found = sp.marker.find(0);
+      var fromCmp = cmp(found.from, from) || extraLeft(sp.marker) - extraLeft(marker);
+      var toCmp = cmp(found.to, to) || extraRight(sp.marker) - extraRight(marker);
+      if (fromCmp >= 0 && toCmp <= 0 || fromCmp <= 0 && toCmp >= 0) continue;
+      if (fromCmp <= 0 && (cmp(found.to, from) > 0 || (sp.marker.inclusiveRight && marker.inclusiveLeft)) ||
+          fromCmp >= 0 && (cmp(found.from, to) < 0 || (sp.marker.inclusiveLeft && marker.inclusiveRight)))
+        return true;
+    }
+  }
+
+  // A visual line is a line as drawn on the screen. Folding, for
+  // example, can cause multiple logical lines to appear on the same
+  // visual line. This finds the start of the visual line that the
+  // given line is part of (usually that is the line itself).
+  function visualLine(line) {
+    var merged;
+    while (merged = collapsedSpanAtStart(line))
+      line = merged.find(-1, true).line;
+    return line;
+  }
+
+  // Returns an array of logical lines that continue the visual line
+  // started by the argument, or undefined if there are no such lines.
+  function visualLineContinued(line) {
+    var merged, lines;
+    while (merged = collapsedSpanAtEnd(line)) {
+      line = merged.find(1, true).line;
+      (lines || (lines = [])).push(line);
+    }
+    return lines;
+  }
+
+  // Get the line number of the start of the visual line that the
+  // given line number is part of.
+  function visualLineNo(doc, lineN) {
+    var line = getLine(doc, lineN), vis = visualLine(line);
+    if (line == vis) return lineN;
+    return lineNo(vis);
+  }
+  // Get the line number of the start of the next visual line after
+  // the given line.
+  function visualLineEndNo(doc, lineN) {
+    if (lineN > doc.lastLine()) return lineN;
+    var line = getLine(doc, lineN), merged;
+    if (!lineIsHidden(doc, line)) return lineN;
+    while (merged = collapsedSpanAtEnd(line))
+      line = merged.find(1, true).line;
+    return lineNo(line) + 1;
+  }
+
+  // Compute whether a line is hidden. Lines count as hidden when they
+  // are part of a visual line that starts with another line, or when
+  // they are entirely covered by collapsed, non-widget span.
+  function lineIsHidden(doc, line) {
+    var sps = sawCollapsedSpans && line.markedSpans;
+    if (sps) for (var sp, i = 0; i < sps.length; ++i) {
+      sp = sps[i];
+      if (!sp.marker.collapsed) continue;
+      if (sp.from == null) return true;
+      if (sp.marker.widgetNode) continue;
+      if (sp.from == 0 && sp.marker.inclusiveLeft && lineIsHiddenInner(doc, line, sp))
+        return true;
+    }
+  }
+  function lineIsHiddenInner(doc, line, span) {
+    if (span.to == null) {
+      var end = span.marker.find(1, true);
+      return lineIsHiddenInner(doc, end.line, getMarkedSpanFor(end.line.markedSpans, span.marker));
+    }
+    if (span.marker.inclusiveRight && span.to == line.text.length)
+      return true;
+    for (var sp, i = 0; i < line.markedSpans.length; ++i) {
+      sp = line.markedSpans[i];
+      if (sp.marker.collapsed && !sp.marker.widgetNode && sp.from == span.to &&
+          (sp.to == null || sp.to != span.from) &&
+          (sp.marker.inclusiveLeft || span.marker.inclusiveRight) &&
+          lineIsHiddenInner(doc, line, sp)) return true;
+    }
+  }
+
+  // LINE WIDGETS
+
+  // Line widgets are block elements displayed above or below a line.
+
+  var LineWidget = CodeMirror.LineWidget = function(doc, node, options) {
+    if (options) for (var opt in options) if (options.hasOwnProperty(opt))
+      this[opt] = options[opt];
+    this.doc = doc;
+    this.node = node;
+  };
+  eventMixin(LineWidget);
+
+  function adjustScrollWhenAboveVisible(cm, line, diff) {
+    if (heightAtLine(line) < ((cm.curOp && cm.curOp.scrollTop) || cm.doc.scrollTop))
+      addToScrollPos(cm, null, diff);
+  }
+
+  LineWidget.prototype.clear = function() {
+    var cm = this.doc.cm, ws = this.line.widgets, line = this.line, no = lineNo(line);
+    if (no == null || !ws) return;
+    for (var i = 0; i < ws.length; ++i) if (ws[i] == this) ws.splice(i--, 1);
+    if (!ws.length) line.widgets = null;
+    var height = widgetHeight(this);
+    updateLineHeight(line, Math.max(0, line.height - height));
+    if (cm) runInOp(cm, function() {
+      adjustScrollWhenAboveVisible(cm, line, -height);
+      regLineChange(cm, no, "widget");
+    });
+  };
+  LineWidget.prototype.changed = function() {
+    var oldH = this.height, cm = this.doc.cm, line = this.line;
+    this.height = null;
+    var diff = widgetHeight(this) - oldH;
+    if (!diff) return;
+    updateLineHeight(line, line.height + diff);
+    if (cm) runInOp(cm, function() {
+      cm.curOp.forceUpdate = true;
+      adjustScrollWhenAboveVisible(cm, line, diff);
+    });
+  };
+
+  function widgetHeight(widget) {
+    if (widget.height != null) return widget.height;
+    var cm = widget.doc.cm;
+    if (!cm) return 0;
+    if (!contains(document.body, widget.node)) {
+      var parentStyle = "position: relative;";
+      if (widget.coverGutter)
+        parentStyle += "margin-left: -" + cm.display.gutters.offsetWidth + "px;";
+      if (widget.noHScroll)
+        parentStyle += "width: " + cm.display.wrapper.clientWidth + "px;";
+      removeChildrenAndAdd(cm.display.measure, elt("div", [widget.node], null, parentStyle));
+    }
+    return widget.height = widget.node.offsetHeight;
+  }
+
+  function addLineWidget(doc, handle, node, options) {
+    var widget = new LineWidget(doc, node, options);
+    var cm = doc.cm;
+    if (cm && widget.noHScroll) cm.display.alignWidgets = true;
+    changeLine(doc, handle, "widget", function(line) {
+      var widgets = line.widgets || (line.widgets = []);
+      if (widget.insertAt == null) widgets.push(widget);
+      else widgets.splice(Math.min(widgets.length - 1, Math.max(0, widget.insertAt)), 0, widget);
+      widget.line = line;
+      if (cm && !lineIsHidden(doc, line)) {
+        var aboveVisible = heightAtLine(line) < doc.scrollTop;
+        updateLineHeight(line, line.height + widgetHeight(widget));
+        if (aboveVisible) addToScrollPos(cm, null, widget.height);
+        cm.curOp.forceUpdate = true;
+      }
+      return true;
+    });
+    return widget;
+  }
+
+  // LINE DATA STRUCTURE
+
+  // Line objects. These hold state related to a line, including
+  // highlighting info (the styles array).
+  var Line = CodeMirror.Line = function(text, markedSpans, estimateHeight) {
+    this.text = text;
+    attachMarkedSpans(this, markedSpans);
+    this.height = estimateHeight ? estimateHeight(this) : 1;
+  };
+  eventMixin(Line);
+  Line.prototype.lineNo = function() { return lineNo(this); };
+
+  // Change the content (text, markers) of a line. Automatically
+  // invalidates cached information and tries to re-estimate the
+  // line's height.
+  function updateLine(line, text, markedSpans, estimateHeight) {
+    line.text = text;
+    if (line.stateAfter) line.stateAfter = null;
+    if (line.styles) line.styles = null;
+    if (line.order != null) line.order = null;
+    detachMarkedSpans(line);
+    attachMarkedSpans(line, markedSpans);
+    var estHeight = estimateHeight ? estimateHeight(line) : 1;
+    if (estHeight != line.height) updateLineHeight(line, estHeight);
+  }
+
+  // Detach a line from the document tree and its markers.
+  function cleanUpLine(line) {
+    line.parent = null;
+    detachMarkedSpans(line);
+  }
+
+  function extractLineClasses(type, output) {
+    if (type) for (;;) {
+      var lineClass = type.match(/(?:^|\s+)line-(background-)?(\S+)/);
+      if (!lineClass) break;
+      type = type.slice(0, lineClass.index) + type.slice(lineClass.index + lineClass[0].length);
+      var prop = lineClass[1] ? "bgClass" : "textClass";
+      if (output[prop] == null)
+        output[prop] = lineClass[2];
+      else if (!(new RegExp("(?:^|\s)" + lineClass[2] + "(?:$|\s)")).test(output[prop]))
+        output[prop] += " " + lineClass[2];
+    }
+    return type;
+  }
+
+  function callBlankLine(mode, state) {
+    if (mode.blankLine) return mode.blankLine(state);
+    if (!mode.innerMode) return;
+    var inner = CodeMirror.innerMode(mode, state);
+    if (inner.mode.blankLine) return inner.mode.blankLine(inner.state);
+  }
+
+  function readToken(mode, stream, state, inner) {
+    for (var i = 0; i < 10; i++) {
+      if (inner) inner[0] = CodeMirror.innerMode(mode, state).mode;
+      var style = mode.token(stream, state);
+      if (stream.pos > stream.start) return style;
+    }
+    throw new Error("Mode " + mode.name + " failed to advance stream.");
+  }
+
+  // Utility for getTokenAt and getLineTokens
+  function takeToken(cm, pos, precise, asArray) {
+    function getObj(copy) {
+      return {start: stream.start, end: stream.pos,
+              string: stream.current(),
+              type: style || null,
+              state: copy ? copyState(doc.mode, state) : state};
+    }
+
+    var doc = cm.doc, mode = doc.mode, style;
+    pos = clipPos(doc, pos);
+    var line = getLine(doc, pos.line), state = getStateBefore(cm, pos.line, precise);
+    var stream = new StringStream(line.text, cm.options.tabSize), tokens;
+    if (asArray) tokens = [];
+    while ((asArray || stream.pos < pos.ch) && !stream.eol()) {
+      stream.start = stream.pos;
+      style = readToken(mode, stream, state);
+      if (asArray) tokens.push(getObj(true));
+    }
+    return asArray ? tokens : getObj();
+  }
+
+  // Run the given mode's parser over a line, calling f for each token.
+  function runMode(cm, text, mode, state, f, lineClasses, forceToEnd) {
+    var flattenSpans = mode.flattenSpans;
+    if (flattenSpans == null) flattenSpans = cm.options.flattenSpans;
+    var curStart = 0, curStyle = null;
+    var stream = new StringStream(text, cm.options.tabSize), style;
+    var inner = cm.options.addModeClass && [null];
+    if (text == "") extractLineClasses(callBlankLine(mode, state), lineClasses);
+    while (!stream.eol()) {
+      if (stream.pos > cm.options.maxHighlightLength) {
+        flattenSpans = false;
+        if (forceToEnd) processLine(cm, text, state, stream.pos);
+        stream.pos = text.length;
+        style = null;
+      } else {
+        style = extractLineClasses(readToken(mode, stream, state, inner), lineClasses);
+      }
+      if (inner) {
+        var mName = inner[0].name;
+        if (mName) style = "m-" + (style ? mName + " " + style : mName);
+      }
+      if (!flattenSpans || curStyle != style) {
+        while (curStart < stream.start) {
+          curStart = Math.min(stream.start, curStart + 50000);
+          f(curStart, curStyle);
+        }
+        curStyle = style;
+      }
+      stream.start = stream.pos;
+    }
+    while (curStart < stream.pos) {
+      // Webkit seems to refuse to render text nodes longer than 57444 characters
+      var pos = Math.min(stream.pos, curStart + 50000);
+      f(pos, curStyle);
+      curStart = pos;
+    }
+  }
+
+  // Compute a style array (an array starting with a mode generation
+  // -- for invalidation -- followed by pairs of end positions and
+  // style strings), which is used to highlight the tokens on the
+  // line.
+  function highlightLine(cm, line, state, forceToEnd) {
+    // A styles array always starts with a number identifying the
+    // mode/overlays that it is based on (for easy invalidation).
+    var st = [cm.state.modeGen], lineClasses = {};
+    // Compute the base array of styles
+    runMode(cm, line.text, cm.doc.mode, state, function(end, style) {
+      st.push(end, style);
+    }, lineClasses, forceToEnd);
+
+    // Run overlays, adjust style array.
+    for (var o = 0; o < cm.state.overlays.length; ++o) {
+      var overlay = cm.state.overlays[o], i = 1, at = 0;
+      runMode(cm, line.text, overlay.mode, true, function(end, style) {
+        var start = i;
+        // Ensure there's a token end at the current position, and that i points at it
+        while (at < end) {
+          var i_end = st[i];
+          if (i_end > end)
+            st.splice(i, 1, end, st[i+1], i_end);
+          i += 2;
+          at = Math.min(end, i_end);
+        }
+        if (!style) return;
+        if (overlay.opaque) {
+          st.splice(start, i - start, end, "cm-overlay " + style);
+          i = start + 2;
+        } else {
+          for (; start < i; start += 2) {
+            var cur = st[start+1];
+            st[start+1] = (cur ? cur + " " : "") + "cm-overlay " + style;
+          }
+        }
+      }, lineClasses);
+    }
+
+    return {styles: st, classes: lineClasses.bgClass || lineClasses.textClass ? lineClasses : null};
+  }
+
+  function getLineStyles(cm, line, updateFrontier) {
+    if (!line.styles || line.styles[0] != cm.state.modeGen) {
+      var result = highlightLine(cm, line, line.stateAfter = getStateBefore(cm, lineNo(line)));
+      line.styles = result.styles;
+      if (result.classes) line.styleClasses = result.classes;
+      else if (line.styleClasses) line.styleClasses = null;
+      if (updateFrontier === cm.doc.frontier) cm.doc.frontier++;
+    }
+    return line.styles;
+  }
+
+  // Lightweight form of highlight -- proceed over this line and
+  // update state, but don't save a style array. Used for lines that
+  // aren't currently visible.
+  function processLine(cm, text, state, startAt) {
+    var mode = cm.doc.mode;
+    var stream = new StringStream(text, cm.options.tabSize);
+    stream.start = stream.pos = startAt || 0;
+    if (text == "") callBlankLine(mode, state);
+    while (!stream.eol() && stream.pos <= cm.options.maxHighlightLength) {
+      readToken(mode, stream, state);
+      stream.start = stream.pos;
+    }
+  }
+
+  // Convert a style as returned by a mode (either null, or a string
+  // containing one or more styles) to a CSS style. This is cached,
+  // and also looks for line-wide styles.
+  var styleToClassCache = {}, styleToClassCacheWithMode = {};
+  function interpretTokenStyle(style, options) {
+    if (!style || /^\s*$/.test(style)) return null;
+    var cache = options.addModeClass ? styleToClassCacheWithMode : styleToClassCache;
+    return cache[style] ||
+      (cache[style] = style.replace(/\S+/g, "cm-$&"));
+  }
+
+  // Render the DOM representation of the text of a line. Also builds
+  // up a 'line map', which points at the DOM nodes that represent
+  // specific stretches of text, and is used by the measuring code.
+  // The returned object contains the DOM node, this map, and
+  // information about line-wide styles that were set by the mode.
+  function buildLineContent(cm, lineView) {
+    // The padding-right forces the element to have a 'border', which
+    // is needed on Webkit to be able to get line-level bounding
+    // rectangles for it (in measureChar).
+    var content = elt("span", null, null, webkit ? "padding-right: .1px" : null);
+    var builder = {pre: elt("pre", [content]), content: content,
+                   col: 0, pos: 0, cm: cm,
+                   splitSpaces: (ie || webkit) && cm.getOption("lineWrapping")};
+    lineView.measure = {};
+
+    // Iterate over the logical lines that make up this visual line.
+    for (var i = 0; i <= (lineView.rest ? lineView.rest.length : 0); i++) {
+      var line = i ? lineView.rest[i - 1] : lineView.line, order;
+      builder.pos = 0;
+      builder.addToken = buildToken;
+      // Optionally wire in some hacks into the token-rendering
+      // algorithm, to deal with browser quirks.
+      if (hasBadBidiRects(cm.display.measure) && (order = getOrder(line)))
+        builder.addToken = buildTokenBadBidi(builder.addToken, order);
+      builder.map = [];
+      var allowFrontierUpdate = lineView != cm.display.externalMeasured && lineNo(line);
+      insertLineContent(line, builder, getLineStyles(cm, line, allowFrontierUpdate));
+      if (line.styleClasses) {
+        if (line.styleClasses.bgClass)
+          builder.bgClass = joinClasses(line.styleClasses.bgClass, builder.bgClass || "");
+        if (line.styleClasses.textClass)
+          builder.textClass = joinClasses(line.styleClasses.textClass, builder.textClass || "");
+      }
+
+      // Ensure at least a single node is present, for measuring.
+      if (builder.map.length == 0)
+        builder.map.push(0, 0, builder.content.appendChild(zeroWidthElement(cm.display.measure)));
+
+      // Store the map and a cache object for the current logical line
+      if (i == 0) {
+        lineView.measure.map = builder.map;
+        lineView.measure.cache = {};
+      } else {
+        (lineView.measure.maps || (lineView.measure.maps = [])).push(builder.map);
+        (lineView.measure.caches || (lineView.measure.caches = [])).push({});
+      }
+    }
+
+    // See issue #2901
+    if (webkit && /\bcm-tab\b/.test(builder.content.lastChild.className))
+      builder.content.className = "cm-tab-wrap-hack";
+
+    signal(cm, "renderLine", cm, lineView.line, builder.pre);
+    if (builder.pre.className)
+      builder.textClass = joinClasses(builder.pre.className, builder.textClass || "");
+
+    return builder;
+  }
+
+  function defaultSpecialCharPlaceholder(ch) {
+    var token = elt("span", "\u2022", "cm-invalidchar");
+    token.title = "\\u" + ch.charCodeAt(0).toString(16);
+    token.setAttribute("aria-label", token.title);
+    return token;
+  }
+
+  // Build up the DOM representation for a single token, and add it to
+  // the line map. Takes care to render special characters separately.
+  function buildToken(builder, text, style, startStyle, endStyle, title, css) {
+    if (!text) return;
+    var displayText = builder.splitSpaces ? text.replace(/ {3,}/g, splitSpaces) : text;
+    var special = builder.cm.state.specialChars, mustWrap = false;
+    if (!special.test(text)) {
+      builder.col += text.length;
+      var content = document.createTextNode(displayText);
+      builder.map.push(builder.pos, builder.pos + text.length, content);
+      if (ie && ie_version < 9) mustWrap = true;
+      builder.pos += text.length;
+    } else {
+      var content = document.createDocumentFragment(), pos = 0;
+      while (true) {
+        special.lastIndex = pos;
+        var m = special.exec(text);
+        var skipped = m ? m.index - pos : text.length - pos;
+        if (skipped) {
+          var txt = document.createTextNode(displayText.slice(pos, pos + skipped));
+          if (ie && ie_version < 9) content.appendChild(elt("span", [txt]));
+          else content.appendChild(txt);
+          builder.map.push(builder.pos, builder.pos + skipped, txt);
+          builder.col += skipped;
+          builder.pos += skipped;
+        }
+        if (!m) break;
+        pos += skipped + 1;
+        if (m[0] == "\t") {
+          var tabSize = builder.cm.options.tabSize, tabWidth = tabSize - builder.col % tabSize;
+          var txt = content.appendChild(elt("span", spaceStr(tabWidth), "cm-tab"));
+          txt.setAttribute("role", "presentation");
+          txt.setAttribute("cm-text", "\t");
+          builder.col += tabWidth;
+        } else {
+          var txt = builder.cm.options.specialCharPlaceholder(m[0]);
+          txt.setAttribute("cm-text", m[0]);
+          if (ie && ie_version < 9) content.appendChild(elt("span", [txt]));
+          else content.appendChild(txt);
+          builder.col += 1;
+        }
+        builder.map.push(builder.pos, builder.pos + 1, txt);
+        builder.pos++;
+      }
+    }
+    if (style || startStyle || endStyle || mustWrap || css) {
+      var fullStyle = style || "";
+      if (startStyle) fullStyle += startStyle;
+      if (endStyle) fullStyle += endStyle;
+      var token = elt("span", [content], fullStyle, css);
+      if (title) token.title = title;
+      return builder.content.appendChild(token);
+    }
+    builder.content.appendChild(content);
+  }
+
+  function splitSpaces(old) {
+    var out = " ";
+    for (var i = 0; i < old.length - 2; ++i) out += i % 2 ? " " : "\u00a0";
+    out += " ";
+    return out;
+  }
+
+  // Work around nonsense dimensions being reported for stretches of
+  // right-to-left text.
+  function buildTokenBadBidi(inner, order) {
+    return function(builder, text, style, startStyle, endStyle, title, css) {
+      style = style ? style + " cm-force-border" : "cm-force-border";
+      var start = builder.pos, end = start + text.length;
+      for (;;) {
+        // Find the part that overlaps with the start of this text
+        for (var i = 0; i < order.length; i++) {
+          var part = order[i];
+          if (part.to > start && part.from <= start) break;
+        }
+        if (part.to >= end) return inner(builder, text, style, startStyle, endStyle, title, css);
+        inner(builder, text.slice(0, part.to - start), style, startStyle, null, title, css);
+        startStyle = null;
+        text = text.slice(part.to - start);
+        start = part.to;
+      }
+    };
+  }
+
+  function buildCollapsedSpan(builder, size, marker, ignoreWidget) {
+    var widget = !ignoreWidget && marker.widgetNode;
+    if (widget) builder.map.push(builder.pos, builder.pos + size, widget);
+    if (!ignoreWidget && builder.cm.display.input.needsContentAttribute) {
+      if (!widget)
+        widget = builder.content.appendChild(document.createElement("span"));
+      widget.setAttribute("cm-marker", marker.id);
+    }
+    if (widget) {
+      builder.cm.display.input.setUneditable(widget);
+      builder.content.appendChild(widget);
+    }
+    builder.pos += size;
+  }
+
+  // Outputs a number of spans to make up a line, taking highlighting
+  // and marked text into account.
+  function insertLineContent(line, builder, styles) {
+    var spans = line.markedSpans, allText = line.text, at = 0;
+    if (!spans) {
+      for (var i = 1; i < styles.length; i+=2)
+        builder.addToken(builder, allText.slice(at, at = styles[i]), interpretTokenStyle(styles[i+1], builder.cm.options));
+      return;
+    }
+
+    var len = allText.length, pos = 0, i = 1, text = "", style, css;
+    var nextChange = 0, spanStyle, spanEndStyle, spanStartStyle, title, collapsed;
+    for (;;) {
+      if (nextChange == pos) { // Update current marker set
+        spanStyle = spanEndStyle = spanStartStyle = title = css = "";
+        collapsed = null; nextChange = Infinity;
+        var foundBookmarks = [];
+        for (var j = 0; j < spans.length; ++j) {
+          var sp = spans[j], m = sp.marker;
+          if (m.type == "bookmark" && sp.from == pos && m.widgetNode) {
+            foundBookmarks.push(m);
+          } else if (sp.from <= pos && (sp.to == null || sp.to > pos || m.collapsed && sp.to == pos && sp.from == pos)) {
+            if (sp.to != null && sp.to != pos && nextChange > sp.to) {
+              nextChange = sp.to;
+              spanEndStyle = "";
+            }
+            if (m.className) spanStyle += " " + m.className;
+            if (m.css) css = m.css;
+            if (m.startStyle && sp.from == pos) spanStartStyle += " " + m.startStyle;
+            if (m.endStyle && sp.to == nextChange) spanEndStyle += " " + m.endStyle;
+            if (m.title && !title) title = m.title;
+            if (m.collapsed && (!collapsed || compareCollapsedMarkers(collapsed.marker, m) < 0))
+              collapsed = sp;
+          } else if (sp.from > pos && nextChange > sp.from) {
+            nextChange = sp.from;
+          }
+        }
+        if (collapsed && (collapsed.from || 0) == pos) {
+          buildCollapsedSpan(builder, (collapsed.to == null ? len + 1 : collapsed.to) - pos,
+                             collapsed.marker, collapsed.from == null);
+          if (collapsed.to == null) return;
+          if (collapsed.to == pos) collapsed = false;
+        }
+        if (!collapsed && foundBookmarks.length) for (var j = 0; j < foundBookmarks.length; ++j)
+          buildCollapsedSpan(builder, 0, foundBookmarks[j]);
+      }
+      if (pos >= len) break;
+
+      var upto = Math.min(len, nextChange);
+      while (true) {
+        if (text) {
+          var end = pos + text.length;
+          if (!collapsed) {
+            var tokenText = end > upto ? text.slice(0, upto - pos) : text;
+            builder.addToken(builder, tokenText, style ? style + spanStyle : spanStyle,
+                             spanStartStyle, pos + tokenText.length == nextChange ? spanEndStyle : "", title, css);
+          }
+          if (end >= upto) {text = text.slice(upto - pos); pos = upto; break;}
+          pos = end;
+          spanStartStyle = "";
+        }
+        text = allText.slice(at, at = styles[i++]);
+        style = interpretTokenStyle(styles[i++], builder.cm.options);
+      }
+    }
+  }
+
+  // DOCUMENT DATA STRUCTURE
+
+  // By default, updates that start and end at the beginning of a line
+  // are treated specially, in order to make the association of line
+  // widgets and marker elements with the text behave more intuitive.
+  function isWholeLineUpdate(doc, change) {
+    return change.from.ch == 0 && change.to.ch == 0 && lst(change.text) == "" &&
+      (!doc.cm || doc.cm.options.wholeLineUpdateBefore);
+  }
+
+  // Perform a change on the document data structure.
+  function updateDoc(doc, change, markedSpans, estimateHeight) {
+    function spansFor(n) {return markedSpans ? markedSpans[n] : null;}
+    function update(line, text, spans) {
+      updateLine(line, text, spans, estimateHeight);
+      signalLater(line, "change", line, change);
+    }
+    function linesFor(start, end) {
+      for (var i = start, result = []; i < end; ++i)
+        result.push(new Line(text[i], spansFor(i), estimateHeight));
+      return result;
+    }
+
+    var from = change.from, to = change.to, text = change.text;
+    var firstLine = getLine(doc, from.line), lastLine = getLine(doc, to.line);
+    var lastText = lst(text), lastSpans = spansFor(text.length - 1), nlines = to.line - from.line;
+
+    // Adjust the line structure
+    if (change.full) {
+      doc.insert(0, linesFor(0, text.length));
+      doc.remove(text.length, doc.size - text.length);
+    } else if (isWholeLineUpdate(doc, change)) {
+      // This is a whole-line replace. Treated specially to make
+      // sure line objects move the way they are supposed to.
+      var added = linesFor(0, text.length - 1);
+      update(lastLine, lastLine.text, lastSpans);
+      if (nlines) doc.remove(from.line, nlines);
+      if (added.length) doc.insert(from.line, added);
+    } else if (firstLine == lastLine) {
+      if (text.length == 1) {
+        update(firstLine, firstLine.text.slice(0, from.ch) + lastText + firstLine.text.slice(to.ch), lastSpans);
+      } else {
+        var added = linesFor(1, text.length - 1);
+        added.push(new Line(lastText + firstLine.text.slice(to.ch), lastSpans, estimateHeight));
+        update(firstLine, firstLine.text.slice(0, from.ch) + text[0], spansFor(0));
+        doc.insert(from.line + 1, added);
+      }
+    } else if (text.length == 1) {
+      update(firstLine, firstLine.text.slice(0, from.ch) + text[0] + lastLine.text.slice(to.ch), spansFor(0));
+      doc.remove(from.line + 1, nlines);
+    } else {
+      update(firstLine, firstLine.text.slice(0, from.ch) + text[0], spansFor(0));
+      update(lastLine, lastText + lastLine.text.slice(to.ch), lastSpans);
+      var added = linesFor(1, text.length - 1);
+      if (nlines > 1) doc.remove(from.line + 1, nlines - 1);
+      doc.insert(from.line + 1, added);
+    }
+
+    signalLater(doc, "change", doc, change);
+  }
+
+  // The document is represented as a BTree consisting of leaves, with
+  // chunk of lines in them, and branches, with up to ten leaves or
+  // other branch nodes below them. The top node is always a branch
+  // node, and is the document object itself (meaning it has
+  // additional methods and properties).
+  //
+  // All nodes have parent links. The tree is used both to go from
+  // line numbers to line objects, and to go from objects to numbers.
+  // It also indexes by height, and is used to convert between height
+  // and line object, and to find the total height of the document.
+  //
+  // See also http://marijnhaverbeke.nl/blog/codemirror-line-tree.html
+
+  function LeafChunk(lines) {
+    this.lines = lines;
+    this.parent = null;
+    for (var i = 0, height = 0; i < lines.length; ++i) {
+      lines[i].parent = this;
+      height += lines[i].height;
+    }
+    this.height = height;
+  }
+
+  LeafChunk.prototype = {
+    chunkSize: function() { return this.lines.length; },
+    // Remove the n lines at offset 'at'.
+    removeInner: function(at, n) {
+      for (var i = at, e = at + n; i < e; ++i) {
+        var line = this.lines[i];
+        this.height -= line.height;
+        cleanUpLine(line);
+        signalLater(line, "delete");
+      }
+      this.lines.splice(at, n);
+    },
+    // Helper used to collapse a small branch into a single leaf.
+    collapse: function(lines) {
+      lines.push.apply(lines, this.lines);
+    },
+    // Insert the given array of lines at offset 'at', count them as
+    // having the given height.
+    insertInner: function(at, lines, height) {
+      this.height += height;
+      this.lines = this.lines.slice(0, at).concat(lines).concat(this.lines.slice(at));
+      for (var i = 0; i < lines.length; ++i) lines[i].parent = this;
+    },
+    // Used to iterate over a part of the tree.
+    iterN: function(at, n, op) {
+      for (var e = at + n; at < e; ++at)
+        if (op(this.lines[at])) return true;
+    }
+  };
+
+  function BranchChunk(children) {
+    this.children = children;
+    var size = 0, height = 0;
+    for (var i = 0; i < children.length; ++i) {
+      var ch = children[i];
+      size += ch.chunkSize(); height += ch.height;
+      ch.parent = this;
+    }
+    this.size = size;
+    this.height = height;
+    this.parent = null;
+  }
+
+  BranchChunk.prototype = {
+    chunkSize: function() { return this.size; },
+    removeInner: function(at, n) {
+      this.size -= n;
+      for (var i = 0; i < this.children.length; ++i) {
+        var child = this.children[i], sz = child.chunkSize();
+        if (at < sz) {
+          var rm = Math.min(n, sz - at), oldHeight = child.height;
+          child.removeInner(at, rm);
+          this.height -= oldHeight - child.height;
+          if (sz == rm) { this.children.splice(i--, 1); child.parent = null; }
+          if ((n -= rm) == 0) break;
+          at = 0;
+        } else at -= sz;
+      }
+      // If the result is smaller than 25 lines, ensure that it is a
+      // single leaf node.
+      if (this.size - n < 25 &&
+          (this.children.length > 1 || !(this.children[0] instanceof LeafChunk))) {
+        var lines = [];
+        this.collapse(lines);
+        this.children = [new LeafChunk(lines)];
+        this.children[0].parent = this;
+      }
+    },
+    collapse: function(lines) {
+      for (var i = 0; i < this.children.length; ++i) this.children[i].collapse(lines);
+    },
+    insertInner: function(at, lines, height) {
+      this.size += lines.length;
+      this.height += height;
+      for (var i = 0; i < this.children.length; ++i) {
+        var child = this.children[i], sz = child.chunkSize();
+        if (at <= sz) {
+          child.insertInner(at, lines, height);
+          if (child.lines && child.lines.length > 50) {
+            while (child.lines.length > 50) {
+              var spilled = child.lines.splice(child.lines.length - 25, 25);
+              var newleaf = new LeafChunk(spilled);
+              child.height -= newleaf.height;
+              this.children.splice(i + 1, 0, newleaf);
+              newleaf.parent = this;
+            }
+            this.maybeSpill();
+          }
+          break;
+        }
+        at -= sz;
+      }
+    },
+    // When a node has grown, check whether it should be split.
+    maybeSpill: function() {
+      if (this.children.length <= 10) return;
+      var me = this;
+      do {
+        var spilled = me.children.splice(me.children.length - 5, 5);
+        var sibling = new BranchChunk(spilled);
+        if (!me.parent) { // Become the parent node
+          var copy = new BranchChunk(me.children);
+          copy.parent = me;
+          me.children = [copy, sibling];
+          me = copy;
+        } else {
+          me.size -= sibling.size;
+          me.height -= sibling.height;
+          var myIndex = indexOf(me.parent.children, me);
+          me.parent.children.splice(myIndex + 1, 0, sibling);
+        }
+        sibling.parent = me.parent;
+      } while (me.children.length > 10);
+      me.parent.maybeSpill();
+    },
+    iterN: function(at, n, op) {
+      for (var i = 0; i < this.children.length; ++i) {
+        var child = this.children[i], sz = child.chunkSize();
+        if (at < sz) {
+          var used = Math.min(n, sz - at);
+          if (child.iterN(at, used, op)) return true;
+          if ((n -= used) == 0) break;
+          at = 0;
+        } else at -= sz;
+      }
+    }
+  };
+
+  var nextDocId = 0;
+  var Doc = CodeMirror.Doc = function(text, mode, firstLine) {
+    if (!(this instanceof Doc)) return new Doc(text, mode, firstLine);
+    if (firstLine == null) firstLine = 0;
+
+    BranchChunk.call(this, [new LeafChunk([new Line("", null)])]);
+    this.first = firstLine;
+    this.scrollTop = this.scrollLeft = 0;
+    this.cantEdit = false;
+    this.cleanGeneration = 1;
+    this.frontier = firstLine;
+    var start = Pos(firstLine, 0);
+    this.sel = simpleSelection(start);
+    this.history = new History(null);
+    this.id = ++nextDocId;
+    this.modeOption = mode;
+
+    if (typeof text == "string") text = splitLines(text);
+    updateDoc(this, {from: start, to: start, text: text});
+    setSelection(this, simpleSelection(start), sel_dontScroll);
+  };
+
+  Doc.prototype = createObj(BranchChunk.prototype, {
+    constructor: Doc,
+    // Iterate over the document. Supports two forms -- with only one
+    // argument, it calls that for each line in the document. With
+    // three, it iterates over the range given by the first two (with
+    // the second being non-inclusive).
+    iter: function(from, to, op) {
+      if (op) this.iterN(from - this.first, to - from, op);
+      else this.iterN(this.first, this.first + this.size, from);
+    },
+
+    // Non-public interface for adding and removing lines.
+    insert: function(at, lines) {
+      var height = 0;
+      for (var i = 0; i < lines.length; ++i) height += lines[i].height;
+      this.insertInner(at - this.first, lines, height);
+    },
+    remove: function(at, n) { this.removeInner(at - this.first, n); },
+
+    // From here, the methods are part of the public interface. Most
+    // are also available from CodeMirror (editor) instances.
+
+    getValue: function(lineSep) {
+      var lines = getLines(this, this.first, this.first + this.size);
+      if (lineSep === false) return lines;
+      return lines.join(lineSep || "\n");
+    },
+    setValue: docMethodOp(function(code) {
+      var top = Pos(this.first, 0), last = this.first + this.size - 1;
+      makeChange(this, {from: top, to: Pos(last, getLine(this, last).text.length),
+                        text: splitLines(code), origin: "setValue", full: true}, true);
+      setSelection(this, simpleSelection(top));
+    }),
+    replaceRange: function(code, from, to, origin) {
+      from = clipPos(this, from);
+      to = to ? clipPos(this, to) : from;
+      replaceRange(this, code, from, to, origin);
+    },
+    getRange: function(from, to, lineSep) {
+      var lines = getBetween(this, clipPos(this, from), clipPos(this, to));
+      if (lineSep === false) return lines;
+      return lines.join(lineSep || "\n");
+    },
+
+    getLine: function(line) {var l = this.getLineHandle(line); return l && l.text;},
+
+    getLineHandle: function(line) {if (isLine(this, line)) return getLine(this, line);},
+    getLineNumber: function(line) {return lineNo(line);},
+
+    getLineHandleVisualStart: function(line) {
+      if (typeof line == "number") line = getLine(this, line);
+      return visualLine(line);
+    },
+
+    lineCount: function() {return this.size;},
+    firstLine: function() {return this.first;},
+    lastLine: function() {return this.first + this.size - 1;},
+
+    clipPos: function(pos) {return clipPos(this, pos);},
+
+    getCursor: function(start) {
+      var range = this.sel.primary(), pos;
+      if (start == null || start == "head") pos = range.head;
+      else if (start == "anchor") pos = range.anchor;
+      else if (start == "end" || start == "to" || start === false) pos = range.to();
+      else pos = range.from();
+      return pos;
+    },
+    listSelections: function() { return this.sel.ranges; },
+    somethingSelected: function() {return this.sel.somethingSelected();},
+
+    setCursor: docMethodOp(function(line, ch, options) {
+      setSimpleSelection(this, clipPos(this, typeof line == "number" ? Pos(line, ch || 0) : line), null, options);
+    }),
+    setSelection: docMethodOp(function(anchor, head, options) {
+      setSimpleSelection(this, clipPos(this, anchor), clipPos(this, head || anchor), options);
+    }),
+    extendSelection: docMethodOp(function(head, other, options) {
+      extendSelection(this, clipPos(this, head), other && clipPos(this, other), options);
+    }),
+    extendSelections: docMethodOp(function(heads, options) {
+      extendSelections(this, clipPosArray(this, heads, options));
+    }),
+    extendSelectionsBy: docMethodOp(function(f, options) {
+      extendSelections(this, map(this.sel.ranges, f), options);
+    }),
+    setSelections: docMethodOp(function(ranges, primary, options) {
+      if (!ranges.length) return;
+      for (var i = 0, out = []; i < ranges.length; i++)
+        out[i] = new Range(clipPos(this, ranges[i].anchor),
+                           clipPos(this, ranges[i].head));
+      if (primary == null) primary = Math.min(ranges.length - 1, this.sel.primIndex);
+      setSelection(this, normalizeSelection(out, primary), options);
+    }),
+    addSelection: docMethodOp(function(anchor, head, options) {
+      var ranges = this.sel.ranges.slice(0);
+      ranges.push(new Range(clipPos(this, anchor), clipPos(this, head || anchor)));
+      setSelection(this, normalizeSelection(ranges, ranges.length - 1), options);
+    }),
+
+    getSelection: function(lineSep) {
+      var ranges = this.sel.ranges, lines;
+      for (var i = 0; i < ranges.length; i++) {
+        var sel = getBetween(this, ranges[i].from(), ranges[i].to());
+        lines = lines ? lines.concat(sel) : sel;
+      }
+      if (lineSep === false) return lines;
+      else return lines.join(lineSep || "\n");
+    },
+    getSelections: function(lineSep) {
+      var parts = [], ranges = this.sel.ranges;
+      for (var i = 0; i < ranges.length; i++) {
+        var sel = getBetween(this, ranges[i].from(), ranges[i].to());
+        if (lineSep !== false) sel = sel.join(lineSep || "\n");
+        parts[i] = sel;
+      }
+      return parts;
+    },
+    replaceSelection: function(code, collapse, origin) {
+      var dup = [];
+      for (var i = 0; i < this.sel.ranges.length; i++)
+        dup[i] = code;
+      this.replaceSelections(dup, collapse, origin || "+input");
+    },
+    replaceSelections: docMethodOp(function(code, collapse, origin) {
+      var changes = [], sel = this.sel;
+      for (var i = 0; i < sel.ranges.length; i++) {
+        var range = sel.ranges[i];
+        changes[i] = {from: range.from(), to: range.to(), text: splitLines(code[i]), origin: origin};
+      }
+      var newSel = collapse && collapse != "end" && computeReplacedSel(this, changes, collapse);
+      for (var i = changes.length - 1; i >= 0; i--)
+        makeChange(this, changes[i]);
+      if (newSel) setSelectionReplaceHistory(this, newSel);
+      else if (this.cm) ensureCursorVisible(this.cm);
+    }),
+    undo: docMethodOp(function() {makeChangeFromHistory(this, "undo");}),
+    redo: docMethodOp(function() {makeChangeFromHistory(this, "redo");}),
+    undoSelection: docMethodOp(function() {makeChangeFromHistory(this, "undo", true);}),
+    redoSelection: docMethodOp(function() {makeChangeFromHistory(this, "redo", true);}),
+
+    setExtending: function(val) {this.extend = val;},
+    getExtending: function() {return this.extend;},
+
+    historySize: function() {
+      var hist = this.history, done = 0, undone = 0;
+      for (var i = 0; i < hist.done.length; i++) if (!hist.done[i].ranges) ++done;
+      for (var i = 0; i < hist.undone.length; i++) if (!hist.undone[i].ranges) ++undone;
+      return {undo: done, redo: undone};
+    },
+    clearHistory: function() {this.history = new History(this.history.maxGeneration);},
+
+    markClean: function() {
+      this.cleanGeneration = this.changeGeneration(true);
+    },
+    changeGeneration: function(forceSplit) {
+      if (forceSplit)
+        this.history.lastOp = this.history.lastSelOp = this.history.lastOrigin = null;
+      return this.history.generation;
+    },
+    isClean: function (gen) {
+      return this.history.generation == (gen || this.cleanGeneration);
+    },
+
+    getHistory: function() {
+      return {done: copyHistoryArray(this.history.done),
+              undone: copyHistoryArray(this.history.undone)};
+    },
+    setHistory: function(histData) {
+      var hist = this.history = new History(this.history.maxGeneration);
+      hist.done = copyHistoryArray(histData.done.slice(0), null, true);
+      hist.undone = copyHistoryArray(histData.undone.slice(0), null, true);
+    },
+
+    addLineClass: docMethodOp(function(handle, where, cls) {
+      return changeLine(this, handle, where == "gutter" ? "gutter" : "class", function(line) {
+        var prop = where == "text" ? "textClass"
+                 : where == "background" ? "bgClass"
+                 : where == "gutter" ? "gutterClass" : "wrapClass";
+        if (!line[prop]) line[prop] = cls;
+        else if (classTest(cls).test(line[prop])) return false;
+        else line[prop] += " " + cls;
+        return true;
+      });
+    }),
+    removeLineClass: docMethodOp(function(handle, where, cls) {
+      return changeLine(this, handle, where == "gutter" ? "gutter" : "class", function(line) {
+        var prop = where == "text" ? "textClass"
+                 : where == "background" ? "bgClass"
+                 : where == "gutter" ? "gutterClass" : "wrapClass";
+        var cur = line[prop];
+        if (!cur) return false;
+        else if (cls == null) line[prop] = null;
+        else {
+          var found = cur.match(classTest(cls));
+          if (!found) return false;
+          var end = found.index + found[0].length;
+          line[prop] = cur.slice(0, found.index) + (!found.index || end == cur.length ? "" : " ") + cur.slice(end) || null;
+        }
+        return true;
+      });
+    }),
+
+    addLineWidget: docMethodOp(function(handle, node, options) {
+      return addLineWidget(this, handle, node, options);
+    }),
+    removeLineWidget: function(widget) { widget.clear(); },
+
+    markText: function(from, to, options) {
+      return markText(this, clipPos(this, from), clipPos(this, to), options, "range");
+    },
+    setBookmark: function(pos, options) {
+      var realOpts = {replacedWith: options && (options.nodeType == null ? options.widget : options),
+                      insertLeft: options && options.insertLeft,
+                      clearWhenEmpty: false, shared: options && options.shared,
+                      handleMouseEvents: options && options.handleMouseEvents};
+      pos = clipPos(this, pos);
+      return markText(this, pos, pos, realOpts, "bookmark");
+    },
+    findMarksAt: function(pos) {
+      pos = clipPos(this, pos);
+      var markers = [], spans = getLine(this, pos.line).markedSpans;
+      if (spans) for (var i = 0; i < spans.length; ++i) {
+        var span = spans[i];
+        if ((span.from == null || span.from <= pos.ch) &&
+            (span.to == null || span.to >= pos.ch))
+          markers.push(span.marker.parent || span.marker);
+      }
+      return markers;
+    },
+    findMarks: function(from, to, filter) {
+      from = clipPos(this, from); to = clipPos(this, to);
+      var found = [], lineNo = from.line;
+      this.iter(from.line, to.line + 1, function(line) {
+        var spans = line.markedSpans;
+        if (spans) for (var i = 0; i < spans.length; i++) {
+          var span = spans[i];
+          if (!(lineNo == from.line && from.ch > span.to ||
+                span.from == null && lineNo != from.line||
+                lineNo == to.line && span.from > to.ch) &&
+              (!filter || filter(span.marker)))
+            found.push(span.marker.parent || span.marker);
+        }
+        ++lineNo;
+      });
+      return found;
+    },
+    getAllMarks: function() {
+      var markers = [];
+      this.iter(function(line) {
+        var sps = line.markedSpans;
+        if (sps) for (var i = 0; i < sps.length; ++i)
+          if (sps[i].from != null) markers.push(sps[i].marker);
+      });
+      return markers;
+    },
+
+    posFromIndex: function(off) {
+      var ch, lineNo = this.first;
+      this.iter(function(line) {
+        var sz = line.text.length + 1;
+        if (sz > off) { ch = off; return true; }
+        off -= sz;
+        ++lineNo;
+      });
+      return clipPos(this, Pos(lineNo, ch));
+    },
+    indexFromPos: function (coords) {
+      coords = clipPos(this, coords);
+      var index = coords.ch;
+      if (coords.line < this.first || coords.ch < 0) return 0;
+      this.iter(this.first, coords.line, function (line) {
+        index += line.text.length + 1;
+      });
+      return index;
+    },
+
+    copy: function(copyHistory) {
+      var doc = new Doc(getLines(this, this.first, this.first + this.size), this.modeOption, this.first);
+      doc.scrollTop = this.scrollTop; doc.scrollLeft = this.scrollLeft;
+      doc.sel = this.sel;
+      doc.extend = false;
+      if (copyHistory) {
+        doc.history.undoDepth = this.history.undoDepth;
+        doc.setHistory(this.getHistory());
+      }
+      return doc;
+    },
+
+    linkedDoc: function(options) {
+      if (!options) options = {};
+      var from = this.first, to = this.first + this.size;
+      if (options.from != null && options.from > from) from = options.from;
+      if (options.to != null && options.to < to) to = options.to;
+      var copy = new Doc(getLines(this, from, to), options.mode || this.modeOption, from);
+      if (options.sharedHist) copy.history = this.history;
+      (this.linked || (this.linked = [])).push({doc: copy, sharedHist: options.sharedHist});
+      copy.linked = [{doc: this, isParent: true, sharedHist: options.sharedHist}];
+      copySharedMarkers(copy, findSharedMarkers(this));
+      return copy;
+    },
+    unlinkDoc: function(other) {
+      if (other instanceof CodeMirror) other = other.doc;
+      if (this.linked) for (var i = 0; i < this.linked.length; ++i) {
+        var link = this.linked[i];
+        if (link.doc != other) continue;
+        this.linked.splice(i, 1);
+        other.unlinkDoc(this);
+        detachSharedMarkers(findSharedMarkers(this));
+        break;
+      }
+      // If the histories were shared, split them again
+      if (other.history == this.history) {
+        var splitIds = [other.id];
+        linkedDocs(other, function(doc) {splitIds.push(doc.id);}, true);
+        other.history = new History(null);
+        other.history.done = copyHistoryArray(this.history.done, splitIds);
+        other.history.undone = copyHistoryArray(this.history.undone, splitIds);
+      }
+    },
+    iterLinkedDocs: function(f) {linkedDocs(this, f);},
+
+    getMode: function() {return this.mode;},
+    getEditor: function() {return this.cm;}
+  });
+
+  // Public alias.
+  Doc.prototype.eachLine = Doc.prototype.iter;
+
+  // Set up methods on CodeMirror's prototype to redirect to the editor's document.
+  var dontDelegate = "iter insert remove copy getEditor".split(" ");
+  for (var prop in Doc.prototype) if (Doc.prototype.hasOwnProperty(prop) && indexOf(dontDelegate, prop) < 0)
+    CodeMirror.prototype[prop] = (function(method) {
+      return function() {return method.apply(this.doc, arguments);};
+    })(Doc.prototype[prop]);
+
+  eventMixin(Doc);
+
+  // Call f for all linked documents.
+  function linkedDocs(doc, f, sharedHistOnly) {
+    function propagate(doc, skip, sharedHist) {
+      if (doc.linked) for (var i = 0; i < doc.linked.length; ++i) {
+        var rel = doc.linked[i];
+        if (rel.doc == skip) continue;
+        var shared = sharedHist && rel.sharedHist;
+        if (sharedHistOnly && !shared) continue;
+        f(rel.doc, shared);
+        propagate(rel.doc, doc, shared);
+      }
+    }
+    propagate(doc, null, true);
+  }
+
+  // Attach a document to an editor.
+  function attachDoc(cm, doc) {
+    if (doc.cm) throw new Error("This document is already in use.");
+    cm.doc = doc;
+    doc.cm = cm;
+    estimateLineHeights(cm);
+    loadMode(cm);
+    if (!cm.options.lineWrapping) findMaxLine(cm);
+    cm.options.mode = doc.modeOption;
+    regChange(cm);
+  }
+
+  // LINE UTILITIES
+
+  // Find the line object corresponding to the given line number.
+  function getLine(doc, n) {
+    n -= doc.first;
+    if (n < 0 || n >= doc.size) throw new Error("There is no line " + (n + doc.first) + " in the document.");
+    for (var chunk = doc; !chunk.lines;) {
+      for (var i = 0;; ++i) {
+        var child = chunk.children[i], sz = child.chunkSize();
+        if (n < sz) { chunk = child; break; }
+        n -= sz;
+      }
+    }
+    return chunk.lines[n];
+  }
+
+  // Get the part of a document between two positions, as an array of
+  // strings.
+  function getBetween(doc, start, end) {
+    var out = [], n = start.line;
+    doc.iter(start.line, end.line + 1, function(line) {
+      var text = line.text;
+      if (n == end.line) text = text.slice(0, end.ch);
+      if (n == start.line) text = text.slice(start.ch);
+      out.push(text);
+      ++n;
+    });
+    return out;
+  }
+  // Get the lines between from and to, as array of strings.
+  function getLines(doc, from, to) {
+    var out = [];
+    doc.iter(from, to, function(line) { out.push(line.text); });
+    return out;
+  }
+
+  // Update the height of a line, propagating the height change
+  // upwards to parent nodes.
+  function updateLineHeight(line, height) {
+    var diff = height - line.height;
+    if (diff) for (var n = line; n; n = n.parent) n.height += diff;
+  }
+
+  // Given a line object, find its line number by walking up through
+  // its parent links.
+  function lineNo(line) {
+    if (line.parent == null) return null;
+    var cur = line.parent, no = indexOf(cur.lines, line);
+    for (var chunk = cur.parent; chunk; cur = chunk, chunk = chunk.parent) {
+      for (var i = 0;; ++i) {
+        if (chunk.children[i] == cur) break;
+        no += chunk.children[i].chunkSize();
+      }
+    }
+    return no + cur.first;
+  }
+
+  // Find the line at the given vertical position, using the height
+  // information in the document tree.
+  function lineAtHeight(chunk, h) {
+    var n = chunk.first;
+    outer: do {
+      for (var i = 0; i < chunk.children.length; ++i) {
+        var child = chunk.children[i], ch = child.height;
+        if (h < ch) { chunk = child; continue outer; }
+        h -= ch;
+        n += child.chunkSize();
+      }
+      return n;
+    } while (!chunk.lines);
+    for (var i = 0; i < chunk.lines.length; ++i) {
+      var line = chunk.lines[i], lh = line.height;
+      if (h < lh) break;
+      h -= lh;
+    }
+    return n + i;
+  }
+
+
+  // Find the height above the given line.
+  function heightAtLine(lineObj) {
+    lineObj = visualLine(lineObj);
+
+    var h = 0, chunk = lineObj.parent;
+    for (var i = 0; i < chunk.lines.length; ++i) {
+      var line = chunk.lines[i];
+      if (line == lineObj) break;
+      else h += line.height;
+    }
+    for (var p = chunk.parent; p; chunk = p, p = chunk.parent) {
+      for (var i = 0; i < p.children.length; ++i) {
+        var cur = p.children[i];
+        if (cur == chunk) break;
+        else h += cur.height;
+      }
+    }
+    return h;
+  }
+
+  // Get the bidi ordering for the given line (and cache it). Returns
+  // false for lines that are fully left-to-right, and an array of
+  // BidiSpan objects otherwise.
+  function getOrder(line) {
+    var order = line.order;
+    if (order == null) order = line.order = bidiOrdering(line.text);
+    return order;
+  }
+
+  // HISTORY
+
+  function History(startGen) {
+    // Arrays of change events and selections. Doing something adds an
+    // event to done and clears undo. Undoing moves events from done
+    // to undone, redoing moves them in the other direction.
+    this.done = []; this.undone = [];
+    this.undoDepth = Infinity;
+    // Used to track when changes can be merged into a single undo
+    // event
+    this.lastModTime = this.lastSelTime = 0;
+    this.lastOp = this.lastSelOp = null;
+    this.lastOrigin = this.lastSelOrigin = null;
+    // Used by the isClean() method
+    this.generation = this.maxGeneration = startGen || 1;
+  }
+
+  // Create a history change event from an updateDoc-style change
+  // object.
+  function historyChangeFromChange(doc, change) {
+    var histChange = {from: copyPos(change.from), to: changeEnd(change), text: getBetween(doc, change.from, change.to)};
+    attachLocalSpans(doc, histChange, change.from.line, change.to.line + 1);
+    linkedDocs(doc, function(doc) {attachLocalSpans(doc, histChange, change.from.line, change.to.line + 1);}, true);
+    return histChange;
+  }
+
+  // Pop all selection events off the end of a history array. Stop at
+  // a change event.
+  function clearSelectionEvents(array) {
+    while (array.length) {
+      var last = lst(array);
+      if (last.ranges) array.pop();
+      else break;
+    }
+  }
+
+  // Find the top change event in the history. Pop off selection
+  // events that are in the way.
+  function lastChangeEvent(hist, force) {
+    if (force) {
+      clearSelectionEvents(hist.done);
+      return lst(hist.done);
+    } else if (hist.done.length && !lst(hist.done).ranges) {
+      return lst(hist.done);
+    } else if (hist.done.length > 1 && !hist.done[hist.done.length - 2].ranges) {
+      hist.done.pop();
+      return lst(hist.done);
+    }
+  }
+
+  // Register a change in the history. Merges changes that are within
+  // a single operation, ore are close together with an origin that
+  // allows merging (starting with "+") into a single event.
+  function addChangeToHistory(doc, change, selAfter, opId) {
+    var hist = doc.history;
+    hist.undone.length = 0;
+    var time = +new Date, cur;
+
+    if ((hist.lastOp == opId ||
+         hist.lastOrigin == change.origin && change.origin &&
+         ((change.origin.charAt(0) == "+" && doc.cm && hist.lastModTime > time - doc.cm.options.historyEventDelay) ||
+          change.origin.charAt(0) == "*")) &&
+        (cur = lastChangeEvent(hist, hist.lastOp == opId))) {
+      // Merge this change into the last event
+      var last = lst(cur.changes);
+      if (cmp(change.from, change.to) == 0 && cmp(change.from, last.to) == 0) {
+        // Optimized case for simple insertion -- don't want to add
+        // new changesets for every character typed
+        last.to = changeEnd(change);
+      } else {
+        // Add new sub-event
+        cur.changes.push(historyChangeFromChange(doc, change));
+      }
+    } else {
+      // Can not be merged, start a new event.
+      var before = lst(hist.done);
+      if (!before || !before.ranges)
+        pushSelectionToHistory(doc.sel, hist.done);
+      cur = {changes: [historyChangeFromChange(doc, change)],
+             generation: hist.generation};
+      hist.done.push(cur);
+      while (hist.done.length > hist.undoDepth) {
+        hist.done.shift();
+        if (!hist.done[0].ranges) hist.done.shift();
+      }
+    }
+    hist.done.push(selAfter);
+    hist.generation = ++hist.maxGeneration;
+    hist.lastModTime = hist.lastSelTime = time;
+    hist.lastOp = hist.lastSelOp = opId;
+    hist.lastOrigin = hist.lastSelOrigin = change.origin;
+
+    if (!last) signal(doc, "historyAdded");
+  }
+
+  function selectionEventCanBeMerged(doc, origin, prev, sel) {
+    var ch = origin.charAt(0);
+    return ch == "*" ||
+      ch == "+" &&
+      prev.ranges.length == sel.ranges.length &&
+      prev.somethingSelected() == sel.somethingSelected() &&
+      new Date - doc.history.lastSelTime <= (doc.cm ? doc.cm.options.historyEventDelay : 500);
+  }
+
+  // Called whenever the selection changes, sets the new selection as
+  // the pending selection in the history, and pushes the old pending
+  // selection into the 'done' array when it was significantly
+  // different (in number of selected ranges, emptiness, or time).
+  function addSelectionToHistory(doc, sel, opId, options) {
+    var hist = doc.history, origin = options && options.origin;
+
+    // A new event is started when the previous origin does not match
+    // the current, or the origins don't allow matching. Origins
+    // starting with * are always merged, those starting with + are
+    // merged when similar and close together in time.
+    if (opId == hist.lastSelOp ||
+        (origin && hist.lastSelOrigin == origin &&
+         (hist.lastModTime == hist.lastSelTime && hist.lastOrigin == origin ||
+          selectionEventCanBeMerged(doc, origin, lst(hist.done), sel))))
+      hist.done[hist.done.length - 1] = sel;
+    else
+      pushSelectionToHistory(sel, hist.done);
+
+    hist.lastSelTime = +new Date;
+    hist.lastSelOrigin = origin;
+    hist.lastSelOp = opId;
+    if (options && options.clearRedo !== false)
+      clearSelectionEvents(hist.undone);
+  }
+
+  function pushSelectionToHistory(sel, dest) {
+    var top = lst(dest);
+    if (!(top && top.ranges && top.equals(sel)))
+      dest.push(sel);
+  }
+
+  // Used to store marked span information in the history.
+  function attachLocalSpans(doc, change, from, to) {
+    var existing = change["spans_" + doc.id], n = 0;
+    doc.iter(Math.max(doc.first, from), Math.min(doc.first + doc.size, to), function(line) {
+      if (line.markedSpans)
+        (existing || (existing = change["spans_" + doc.id] = {}))[n] = line.markedSpans;
+      ++n;
+    });
+  }
+
+  // When un/re-doing restores text containing marked spans, those
+  // that have been explicitly cleared should not be restored.
+  function removeClearedSpans(spans) {
+    if (!spans) return null;
+    for (var i = 0, out; i < spans.length; ++i) {
+      if (spans[i].marker.explicitlyCleared) { if (!out) out = spans.slice(0, i); }
+      else if (out) out.push(spans[i]);
+    }
+    return !out ? spans : out.length ? out : null;
+  }
+
+  // Retrieve and filter the old marked spans stored in a change event.
+  function getOldSpans(doc, change) {
+    var found = change["spans_" + doc.id];
+    if (!found) return null;
+    for (var i = 0, nw = []; i < change.text.length; ++i)
+      nw.push(removeClearedSpans(found[i]));
+    return nw;
+  }
+
+  // Used both to provide a JSON-safe object in .getHistory, and, when
+  // detaching a document, to split the history in two
+  function copyHistoryArray(events, newGroup, instantiateSel) {
+    for (var i = 0, copy = []; i < events.length; ++i) {
+      var event = events[i];
+      if (event.ranges) {
+        copy.push(instantiateSel ? Selection.prototype.deepCopy.call(event) : event);
+        continue;
+      }
+      var changes = event.changes, newChanges = [];
+      copy.push({changes: newChanges});
+      for (var j = 0; j < changes.length; ++j) {
+        var change = changes[j], m;
+        newChanges.push({from: change.from, to: change.to, text: change.text});
+        if (newGroup) for (var prop in change) if (m = prop.match(/^spans_(\d+)$/)) {
+          if (indexOf(newGroup, Number(m[1])) > -1) {
+            lst(newChanges)[prop] = change[prop];
+            delete change[prop];
+          }
+        }
+      }
+    }
+    return copy;
+  }
+
+  // Rebasing/resetting history to deal with externally-sourced changes
+
+  function rebaseHistSelSingle(pos, from, to, diff) {
+    if (to < pos.line) {
+      pos.line += diff;
+    } else if (from < pos.line) {
+      pos.line = from;
+      pos.ch = 0;
+    }
+  }
+
+  // Tries to rebase an array of history events given a change in the
+  // document. If the change touches the same lines as the event, the
+  // event, and everything 'behind' it, is discarded. If the change is
+  // before the event, the event's positions are updated. Uses a
+  // copy-on-write scheme for the positions, to avoid having to
+  // reallocate them all on every rebase, but also avoid problems with
+  // shared position objects being unsafely updated.
+  function rebaseHistArray(array, from, to, diff) {
+    for (var i = 0; i < array.length; ++i) {
+      var sub = array[i], ok = true;
+      if (sub.ranges) {
+        if (!sub.copied) { sub = array[i] = sub.deepCopy(); sub.copied = true; }
+        for (var j = 0; j < sub.ranges.length; j++) {
+          rebaseHistSelSingle(sub.ranges[j].anchor, from, to, diff);
+          rebaseHistSelSingle(sub.ranges[j].head, from, to, diff);
+        }
+        continue;
+      }
+      for (var j = 0; j < sub.changes.length; ++j) {
+        var cur = sub.changes[j];
+        if (to < cur.from.line) {
+          cur.from = Pos(cur.from.line + diff, cur.from.ch);
+          cur.to = Pos(cur.to.line + diff, cur.to.ch);
+        } else if (from <= cur.to.line) {
+          ok = false;
+          break;
+        }
+      }
+      if (!ok) {
+        array.splice(0, i + 1);
+        i = 0;
+      }
+    }
+  }
+
+  function rebaseHist(hist, change) {
+    var from = change.from.line, to = change.to.line, diff = change.text.length - (to - from) - 1;
+    rebaseHistArray(hist.done, from, to, diff);
+    rebaseHistArray(hist.undone, from, to, diff);
+  }
+
+  // EVENT UTILITIES
+
+  // Due to the fact that we still support jurassic IE versions, some
+  // compatibility wrappers are needed.
+
+  var e_preventDefault = CodeMirror.e_preventDefault = function(e) {
+    if (e.preventDefault) e.preventDefault();
+    else e.returnValue = false;
+  };
+  var e_stopPropagation = CodeMirror.e_stopPropagation = function(e) {
+    if (e.stopPropagation) e.stopPropagation();
+    else e.cancelBubble = true;
+  };
+  function e_defaultPrevented(e) {
+    return e.defaultPrevented != null ? e.defaultPrevented : e.returnValue == false;
+  }
+  var e_stop = CodeMirror.e_stop = function(e) {e_preventDefault(e); e_stopPropagation(e);};
+
+  function e_target(e) {return e.target || e.srcElement;}
+  function e_button(e) {
+    var b = e.which;
+    if (b == null) {
+      if (e.button & 1) b = 1;
+      else if (e.button & 2) b = 3;
+      else if (e.button & 4) b = 2;
+    }
+    if (mac && e.ctrlKey && b == 1) b = 3;
+    return b;
+  }
+
+  // EVENT HANDLING
+
+  // Lightweight event framework. on/off also work on DOM nodes,
+  // registering native DOM handlers.
+
+  var on = CodeMirror.on = function(emitter, type, f) {
+    if (emitter.addEventListener)
+      emitter.addEventListener(type, f, false);
+    else if (emitter.attachEvent)
+      emitter.attachEvent("on" + type, f);
+    else {
+      var map = emitter._handlers || (emitter._handlers = {});
+      var arr = map[type] || (map[type] = []);
+      arr.push(f);
+    }
+  };
+
+  var off = CodeMirror.off = function(emitter, type, f) {
+    if (emitter.removeEventListener)
+      emitter.removeEventListener(type, f, false);
+    else if (emitter.detachEvent)
+      emitter.detachEvent("on" + type, f);
+    else {
+      var arr = emitter._handlers && emitter._handlers[type];
+      if (!arr) return;
+      for (var i = 0; i < arr.length; ++i)
+        if (arr[i] == f) { arr.splice(i, 1); break; }
+    }
+  };
+
+  var signal = CodeMirror.signal = function(emitter, type /*, values...*/) {
+    var arr = emitter._handlers && emitter._handlers[type];
+    if (!arr) return;
+    var args = Array.prototype.slice.call(arguments, 2);
+    for (var i = 0; i < arr.length; ++i) arr[i].apply(null, args);
+  };
+
+  var orphanDelayedCallbacks = null;
+
+  // Often, we want to signal events at a point where we are in the
+  // middle of some work, but don't want the handler to start calling
+  // other methods on the editor, which might be in an inconsistent
+  // state or simply not expect any other events to happen.
+  // signalLater looks whether there are any handlers, and schedules
+  // them to be executed when the last operation ends, or, if no
+  // operation is active, when a timeout fires.
+  function signalLater(emitter, type /*, values...*/) {
+    var arr = emitter._handlers && emitter._handlers[type];
+    if (!arr) return;
+    var args = Array.prototype.slice.call(arguments, 2), list;
+    if (operationGroup) {
+      list = operationGroup.delayedCallbacks;
+    } else if (orphanDelayedCallbacks) {
+      list = orphanDelayedCallbacks;
+    } else {
+      list = orphanDelayedCallbacks = [];
+      setTimeout(fireOrphanDelayed, 0);
+    }
+    function bnd(f) {return function(){f.apply(null, args);};};
+    for (var i = 0; i < arr.length; ++i)
+      list.push(bnd(arr[i]));
+  }
+
+  function fireOrphanDelayed() {
+    var delayed = orphanDelayedCallbacks;
+    orphanDelayedCallbacks = null;
+    for (var i = 0; i < delayed.length; ++i) delayed[i]();
+  }
+
+  // The DOM events that CodeMirror handles can be overridden by
+  // registering a (non-DOM) handler on the editor for the event name,
+  // and preventDefault-ing the event in that handler.
+  function signalDOMEvent(cm, e, override) {
+    if (typeof e == "string")
+      e = {type: e, preventDefault: function() { this.defaultPrevented = true; }};
+    signal(cm, override || e.type, cm, e);
+    return e_defaultPrevented(e) || e.codemirrorIgnore;
+  }
+
+  function signalCursorActivity(cm) {
+    var arr = cm._handlers && cm._handlers.cursorActivity;
+    if (!arr) return;
+    var set = cm.curOp.cursorActivityHandlers || (cm.curOp.cursorActivityHandlers = []);
+    for (var i = 0; i < arr.length; ++i) if (indexOf(set, arr[i]) == -1)
+      set.push(arr[i]);
+  }
+
+  function hasHandler(emitter, type) {
+    var arr = emitter._handlers && emitter._handlers[type];
+    return arr && arr.length > 0;
+  }
+
+  // Add on and off methods to a constructor's prototype, to make
+  // registering events on such objects more convenient.
+  function eventMixin(ctor) {
+    ctor.prototype.on = function(type, f) {on(this, type, f);};
+    ctor.prototype.off = function(type, f) {off(this, type, f);};
+  }
+
+  // MISC UTILITIES
+
+  // Number of pixels added to scroller and sizer to hide scrollbar
+  var scrollerGap = 30;
+
+  // Returned or thrown by various protocols to signal 'I'm not
+  // handling this'.
+  var Pass = CodeMirror.Pass = {toString: function(){return "CodeMirror.Pass";}};
+
+  // Reused option objects for setSelection & friends
+  var sel_dontScroll = {scroll: false}, sel_mouse = {origin: "*mouse"}, sel_move = {origin: "+move"};
+
+  function Delayed() {this.id = null;}
+  Delayed.prototype.set = function(ms, f) {
+    clearTimeout(this.id);
+    this.id = setTimeout(f, ms);
+  };
+
+  // Counts the column offset in a string, taking tabs into account.
+  // Used mostly to find indentation.
+  var countColumn = CodeMirror.countColumn = function(string, end, tabSize, startIndex, startValue) {
+    if (end == null) {
+      end = string.search(/[^\s\u00a0]/);
+      if (end == -1) end = string.length;
+    }
+    for (var i = startIndex || 0, n = startValue || 0;;) {
+      var nextTab = string.indexOf("\t", i);
+      if (nextTab < 0 || nextTab >= end)
+        return n + (end - i);
+      n += nextTab - i;
+      n += tabSize - (n % tabSize);
+      i = nextTab + 1;
+    }
+  };
+
+  // The inverse of countColumn -- find the offset that corresponds to
+  // a particular column.
+  function findColumn(string, goal, tabSize) {
+    for (var pos = 0, col = 0;;) {
+      var nextTab = string.indexOf("\t", pos);
+      if (nextTab == -1) nextTab = string.length;
+      var skipped = nextTab - pos;
+      if (nextTab == string.length || col + skipped >= goal)
+        return pos + Math.min(skipped, goal - col);
+      col += nextTab - pos;
+      col += tabSize - (col % tabSize);
+      pos = nextTab + 1;
+      if (col >= goal) return pos;
+    }
+  }
+
+  var spaceStrs = [""];
+  function spaceStr(n) {
+    while (spaceStrs.length <= n)
+      spaceStrs.push(lst(spaceStrs) + " ");
+    return spaceStrs[n];
+  }
+
+  function lst(arr) { return arr[arr.length-1]; }
+
+  var selectInput = function(node) { node.select(); };
+  if (ios) // Mobile Safari apparently has a bug where select() is broken.
+    selectInput = function(node) { node.selectionStart = 0; node.selectionEnd = node.value.length; };
+  else if (ie) // Suppress mysterious IE10 errors
+    selectInput = function(node) { try { node.select(); } catch(_e) {} };
+
+  function indexOf(array, elt) {
+    for (var i = 0; i < array.length; ++i)
+      if (array[i] == elt) return i;
+    return -1;
+  }
+  function map(array, f) {
+    var out = [];
+    for (var i = 0; i < array.length; i++) out[i] = f(array[i], i);
+    return out;
+  }
+
+  function nothing() {}
+
+  function createObj(base, props) {
+    var inst;
+    if (Object.create) {
+      inst = Object.create(base);
+    } else {
+      nothing.prototype = base;
+      inst = new nothing();
+    }
+    if (props) copyObj(props, inst);
+    return inst;
+  };
+
+  function copyObj(obj, target, overwrite) {
+    if (!target) target = {};
+    for (var prop in obj)
+      if (obj.hasOwnProperty(prop) && (overwrite !== false || !target.hasOwnProperty(prop)))
+        target[prop] = obj[prop];
+    return target;
+  }
+
+  function bind(f) {
+    var args = Array.prototype.slice.call(arguments, 1);
+    return function(){return f.apply(null, args);};
+  }
+
+  var nonASCIISingleCaseWordChar = /[\u00df\u0587\u0590-\u05f4\u0600-\u06ff\u3040-\u309f\u30a0-\u30ff\u3400-\u4db5\u4e00-\u9fcc\uac00-\ud7af]/;
+  var isWordCharBasic = CodeMirror.isWordChar = function(ch) {
+    return /\w/.test(ch) || ch > "\x80" &&
+      (ch.toUpperCase() != ch.toLowerCase() || nonASCIISingleCaseWordChar.test(ch));
+  };
+  function isWordChar(ch, helper) {
+    if (!helper) return isWordCharBasic(ch);
+    if (helper.source.indexOf("\\w") > -1 && isWordCharBasic(ch)) return true;
+    return helper.test(ch);
+  }
+
+  function isEmpty(obj) {
+    for (var n in obj) if (obj.hasOwnProperty(n) && obj[n]) return false;
+    return true;
+  }
+
+  // Extending unicode characters. A series of a non-extending char +
+  // any number of extending chars is treated as a single unit as far
+  // as editing and measuring is concerned. This is not fully correct,
+  // since some scripts/fonts/browsers also treat other configurations
+  // of code points as a group.
+  var extendingChars = /[\u0300-\u036f\u0483-\u0489\u0591-\u05bd\u05bf\u05c1\u05c2\u05c4\u05c5\u05c7\u0610-\u061a\u064b-\u065e\u0670\u06d6-\u06dc\u06de-\u06e4\u06e7\u06e8\u06ea-\u06ed\u0711\u0730-\u074a\u07a6-\u07b0\u07eb-\u07f3\u0816-\u0819\u081b-\u0823\u0825-\u0827\u0829-\u082d\u0900-\u0902\u093c\u0941-\u0948\u094d\u0951-\u0955\u0962\u0963\u0981\u09bc\u09be\u09c1-\u09c4\u09cd\u09d7\u09e2\u09e3\u0a01\u0a02\u0a3c\u0a41\u0a42\u0a47\u0a48\u0a4b-\u0a4d\u0a51\u0a70\u0a71\u0a75\u0a81\u0a82\u0abc\u0ac1-\u0ac5\u0ac7\u0ac8\u0acd\u0ae2\u0ae3\u0b01\u0b3c\u0b3e\u0b3f\u0b41-\u0b44\u0b4d\u0b56\u0b57\u0b62\u0b63\u0b82\u0bbe\u0bc0\u0bcd\u0bd7\u0c3e-\u0c40\u0c46-\u0c48\u0c4a-\u0c4d\u0c55\u0c56\u0c62\u0c63\u0cbc\u0cbf\u0cc2\u0cc6\u0ccc\u0ccd\u0cd5\u0cd6\u0ce2\u0ce3\u0d3e\u0d41-\u0d44\u0d4d\u0d57\u0d62\u0d63\u0dca\u0dcf\u0dd2-\u0dd4\u0dd6\u0ddf\u0e31\u0e34-\u0e3a\u0e47-\u0e4e\u0eb1\u0eb4-\u0eb9\u0ebb\u0ebc\u0ec8-\u0ecd\u0f18\u0f19\u0f35\u0f37\u0f39\u0f71-\u0f7e\u0f80-\u0f84\u0f86\u0f87\u0f90-\u0f97\u0f99-\u0fbc\u0fc6\u102d-\u1030\u1032-\u1037\u1039\u103a\u103d\u103e\u1058\u1059\u105e-\u1060\u1071-\u1074\u1082\u1085\u1086\u108d\u109d\u135f\u1712-\u1714\u1732-\u1734\u1752\u1753\u1772\u1773\u17b7-\u17bd\u17c6\u17c9-\u17d3\u17dd\u180b-\u180d\u18a9\u1920-\u1922\u1927\u1928\u1932\u1939-\u193b\u1a17\u1a18\u1a56\u1a58-\u1a5e\u1a60\u1a62\u1a65-\u1a6c\u1a73-\u1a7c\u1a7f\u1b00-\u1b03\u1b34\u1b36-\u1b3a\u1b3c\u1b42\u1b6b-\u1b73\u1b80\u1b81\u1ba2-\u1ba5\u1ba8\u1ba9\u1c2c-\u1c33\u1c36\u1c37\u1cd0-\u1cd2\u1cd4-\u1ce0\u1ce2-\u1ce8\u1ced\u1dc0-\u1de6\u1dfd-\u1dff\u200c\u200d\u20d0-\u20f0\u2cef-\u2cf1\u2de0-\u2dff\u302a-\u302f\u3099\u309a\ua66f-\ua672\ua67c\ua67d\ua6f0\ua6f1\ua802\ua806\ua80b\ua825\ua826\ua8c4\ua8e0-\ua8f1\ua926-\ua92d\ua947-\ua951\ua980-\ua982\ua9b3\ua9b6-\ua9b9\ua9bc\uaa29-\uaa2e\uaa31\uaa32\uaa35\uaa36\uaa43\uaa4c\uaab0\uaab2-\uaab4\uaab7\uaab8\uaabe\uaabf\uaac1\uabe5\uabe8\uabed\udc00-\udfff\ufb1e\ufe00-\ufe0f\ufe20-\ufe26\uff9e\uff9f]/;
+  function isExtendingChar(ch) { return ch.charCodeAt(0) >= 768 && extendingChars.test(ch); }
+
+  // DOM UTILITIES
+
+  function elt(tag, content, className, style) {
+    var e = document.createElement(tag);
+    if (className) e.className = className;
+    if (style) e.style.cssText = style;
+    if (typeof content == "string") e.appendChild(document.createTextNode(content));
+    else if (content) for (var i = 0; i < content.length; ++i) e.appendChild(content[i]);
+    return e;
+  }
+
+  var range;
+  if (document.createRange) range = function(node, start, end, endNode) {
+    var r = document.createRange();
+    r.setEnd(endNode || node, end);
+    r.setStart(node, start);
+    return r;
+  };
+  else range = function(node, start, end) {
+    var r = document.body.createTextRange();
+    try { r.moveToElementText(node.parentNode); }
+    catch(e) { return r; }
+    r.collapse(true);
+    r.moveEnd("character", end);
+    r.moveStart("character", start);
+    return r;
+  };
+
+  function removeChildren(e) {
+    for (var count = e.childNodes.length; count > 0; --count)
+      e.removeChild(e.firstChild);
+    return e;
+  }
+
+  function removeChildrenAndAdd(parent, e) {
+    return removeChildren(parent).appendChild(e);
+  }
+
+  var contains = CodeMirror.contains = function(parent, child) {
+    if (child.nodeType == 3) // Android browser always returns false when child is a textnode
+      child = child.parentNode;
+    if (parent.contains)
+      return parent.contains(child);
+    do {
+      if (child.nodeType == 11) child = child.host;
+      if (child == parent) return true;
+    } while (child = child.parentNode);
+  };
+
+  function activeElt() { return document.activeElement; }
+  // Older versions of IE throws unspecified error when touching
+  // document.activeElement in some cases (during loading, in iframe)
+  if (ie && ie_version < 11) activeElt = function() {
+    try { return document.activeElement; }
+    catch(e) { return document.body; }
+  };
+
+  function classTest(cls) { return new RegExp("(^|\\s)" + cls + "(?:$|\\s)\\s*"); }
+  var rmClass = CodeMirror.rmClass = function(node, cls) {
+    var current = node.className;
+    var match = classTest(cls).exec(current);
+    if (match) {
+      var after = current.slice(match.index + match[0].length);
+      node.className = current.slice(0, match.index) + (after ? match[1] + after : "");
+    }
+  };
+  var addClass = CodeMirror.addClass = function(node, cls) {
+    var current = node.className;
+    if (!classTest(cls).test(current)) node.className += (current ? " " : "") + cls;
+  };
+  function joinClasses(a, b) {
+    var as = a.split(" ");
+    for (var i = 0; i < as.length; i++)
+      if (as[i] && !classTest(as[i]).test(b)) b += " " + as[i];
+    return b;
+  }
+
+  // WINDOW-WIDE EVENTS
+
+  // These must be handled carefully, because naively registering a
+  // handler for each editor will cause the editors to never be
+  // garbage collected.
+
+  function forEachCodeMirror(f) {
+    if (!document.body.getElementsByClassName) return;
+    var byClass = document.body.getElementsByClassName("CodeMirror");
+    for (var i = 0; i < byClass.length; i++) {
+      var cm = byClass[i].CodeMirror;
+      if (cm) f(cm);
+    }
+  }
+
+  var globalsRegistered = false;
+  function ensureGlobalHandlers() {
+    if (globalsRegistered) return;
+    registerGlobalHandlers();
+    globalsRegistered = true;
+  }
+  function registerGlobalHandlers() {
+    // When the window resizes, we need to refresh active editors.
+    var resizeTimer;
+    on(window, "resize", function() {
+      if (resizeTimer == null) resizeTimer = setTimeout(function() {
+        resizeTimer = null;
+        forEachCodeMirror(onResize);
+      }, 100);
+    });
+    // When the window loses focus, we want to show the editor as blurred
+    on(window, "blur", function() {
+      forEachCodeMirror(onBlur);
+    });
+  }
+
+  // FEATURE DETECTION
+
+  // Detect drag-and-drop
+  var dragAndDrop = function() {
+    // There is *some* kind of drag-and-drop support in IE6-8, but I
+    // couldn't get it to work yet.
+    if (ie && ie_version < 9) return false;
+    var div = elt('div');
+    return "draggable" in div || "dragDrop" in div;
+  }();
+
+  var zwspSupported;
+  function zeroWidthElement(measure) {
+    if (zwspSupported == null) {
+      var test = elt("span", "\u200b");
+      removeChildrenAndAdd(measure, elt("span", [test, document.createTextNode("x")]));
+      if (measure.firstChild.offsetHeight != 0)
+        zwspSupported = test.offsetWidth <= 1 && test.offsetHeight > 2 && !(ie && ie_version < 8);
+    }
+    var node = zwspSupported ? elt("span", "\u200b") :
+      elt("span", "\u00a0", null, "display: inline-block; width: 1px; margin-right: -1px");
+    node.setAttribute("cm-text", "");
+    return node;
+  }
+
+  // Feature-detect IE's crummy client rect reporting for bidi text
+  var badBidiRects;
+  function hasBadBidiRects(measure) {
+    if (badBidiRects != null) return badBidiRects;
+    var txt = removeChildrenAndAdd(measure, document.createTextNode("A\u062eA"));
+    var r0 = range(txt, 0, 1).getBoundingClientRect();
+    if (!r0 || r0.left == r0.right) return false; // Safari returns null in some cases (#2780)
+    var r1 = range(txt, 1, 2).getBoundingClientRect();
+    return badBidiRects = (r1.right - r0.right < 3);
+  }
+
+  // See if "".split is the broken IE version, if so, provide an
+  // alternative way to split lines.
+  var splitLines = CodeMirror.splitLines = "\n\nb".split(/\n/).length != 3 ? function(string) {
+    var pos = 0, result = [], l = string.length;
+    while (pos <= l) {
+      var nl = string.indexOf("\n", pos);
+      if (nl == -1) nl = string.length;
+      var line = string.slice(pos, string.charAt(nl - 1) == "\r" ? nl - 1 : nl);
+      var rt = line.indexOf("\r");
+      if (rt != -1) {
+        result.push(line.slice(0, rt));
+        pos += rt + 1;
+      } else {
+        result.push(line);
+        pos = nl + 1;
+      }
+    }
+    return result;
+  } : function(string){return string.split(/\r\n?|\n/);};
+
+  var hasSelection = window.getSelection ? function(te) {
+    try { return te.selectionStart != te.selectionEnd; }
+    catch(e) { return false; }
+  } : function(te) {
+    try {var range = te.ownerDocument.selection.createRange();}
+    catch(e) {}
+    if (!range || range.parentElement() != te) return false;
+    return range.compareEndPoints("StartToEnd", range) != 0;
+  };
+
+  var hasCopyEvent = (function() {
+    var e = elt("div");
+    if ("oncopy" in e) return true;
+    e.setAttribute("oncopy", "return;");
+    return typeof e.oncopy == "function";
+  })();
+
+  var badZoomedRects = null;
+  function hasBadZoomedRects(measure) {
+    if (badZoomedRects != null) return badZoomedRects;
+    var node = removeChildrenAndAdd(measure, elt("span", "x"));
+    var normal = node.getBoundingClientRect();
+    var fromRange = range(node, 0, 1).getBoundingClientRect();
+    return badZoomedRects = Math.abs(normal.left - fromRange.left) > 1;
+  }
+
+  // KEY NAMES
+
+  var keyNames = {3: "Enter", 8: "Backspace", 9: "Tab", 13: "Enter", 16: "Shift", 17: "Ctrl", 18: "Alt",
+                  19: "Pause", 20: "CapsLock", 27: "Esc", 32: "Space", 33: "PageUp", 34: "PageDown", 35: "End",
+                  36: "Home", 37: "Left", 38: "Up", 39: "Right", 40: "Down", 44: "PrintScrn", 45: "Insert",
+                  46: "Delete", 59: ";", 61: "=", 91: "Mod", 92: "Mod", 93: "Mod", 107: "=", 109: "-", 127: "Delete",
+                  173: "-", 186: ";", 187: "=", 188: ",", 189: "-", 190: ".", 191: "/", 192: "`", 219: "[", 220: "\\",
+                  221: "]", 222: "'", 63232: "Up", 63233: "Down", 63234: "Left", 63235: "Right", 63272: "Delete",
+                  63273: "Home", 63275: "End", 63276: "PageUp", 63277: "PageDown", 63302: "Insert"};
+  CodeMirror.keyNames = keyNames;
+  (function() {
+    // Number keys
+    for (var i = 0; i < 10; i++) keyNames[i + 48] = keyNames[i + 96] = String(i);
+    // Alphabetic keys
+    for (var i = 65; i <= 90; i++) keyNames[i] = String.fromCharCode(i);
+    // Function keys
+    for (var i = 1; i <= 12; i++) keyNames[i + 111] = keyNames[i + 63235] = "F" + i;
+  })();
+
+  // BIDI HELPERS
+
+  function iterateBidiSections(order, from, to, f) {
+    if (!order) return f(from, to, "ltr");
+    var found = false;
+    for (var i = 0; i < order.length; ++i) {
+      var part = order[i];
+      if (part.from < to && part.to > from || from == to && part.to == from) {
+        f(Math.max(part.from, from), Math.min(part.to, to), part.level == 1 ? "rtl" : "ltr");
+        found = true;
+      }
+    }
+    if (!found) f(from, to, "ltr");
+  }
+
+  function bidiLeft(part) { return part.level % 2 ? part.to : part.from; }
+  function bidiRight(part) { return part.level % 2 ? part.from : part.to; }
+
+  function lineLeft(line) { var order = getOrder(line); return order ? bidiLeft(order[0]) : 0; }
+  function lineRight(line) {
+    var order = getOrder(line);
+    if (!order) return line.text.length;
+    return bidiRight(lst(order));
+  }
+
+  function lineStart(cm, lineN) {
+    var line = getLine(cm.doc, lineN);
+    var visual = visualLine(line);
+    if (visual != line) lineN = lineNo(visual);
+    var order = getOrder(visual);
+    var ch = !order ? 0 : order[0].level % 2 ? lineRight(visual) : lineLeft(visual);
+    return Pos(lineN, ch);
+  }
+  function lineEnd(cm, lineN) {
+    var merged, line = getLine(cm.doc, lineN);
+    while (merged = collapsedSpanAtEnd(line)) {
+      line = merged.find(1, true).line;
+      lineN = null;
+    }
+    var order = getOrder(line);
+    var ch = !order ? line.text.length : order[0].level % 2 ? lineLeft(line) : lineRight(line);
+    return Pos(lineN == null ? lineNo(line) : lineN, ch);
+  }
+  function lineStartSmart(cm, pos) {
+    var start = lineStart(cm, pos.line);
+    var line = getLine(cm.doc, start.line);
+    var order = getOrder(line);
+    if (!order || order[0].level == 0) {
+      var firstNonWS = Math.max(0, line.text.search(/\S/));
+      var inWS = pos.line == start.line && pos.ch <= firstNonWS && pos.ch;
+      return Pos(start.line, inWS ? 0 : firstNonWS);
+    }
+    return start;
+  }
+
+  function compareBidiLevel(order, a, b) {
+    var linedir = order[0].level;
+    if (a == linedir) return true;
+    if (b == linedir) return false;
+    return a < b;
+  }
+  var bidiOther;
+  function getBidiPartAt(order, pos) {
+    bidiOther = null;
+    for (var i = 0, found; i < order.length; ++i) {
+      var cur = order[i];
+      if (cur.from < pos && cur.to > pos) return i;
+      if ((cur.from == pos || cur.to == pos)) {
+        if (found == null) {
+          found = i;
+        } else if (compareBidiLevel(order, cur.level, order[found].level)) {
+          if (cur.from != cur.to) bidiOther = found;
+          return i;
+        } else {
+          if (cur.from != cur.to) bidiOther = i;
+          return found;
+        }
+      }
+    }
+    return found;
+  }
+
+  function moveInLine(line, pos, dir, byUnit) {
+    if (!byUnit) return pos + dir;
+    do pos += dir;
+    while (pos > 0 && isExtendingChar(line.text.charAt(pos)));
+    return pos;
+  }
+
+  // This is needed in order to move 'visually' through bi-directional
+  // text -- i.e., pressing left should make the cursor go left, even
+  // when in RTL text. The tricky part is the 'jumps', where RTL and
+  // LTR text touch each other. This often requires the cursor offset
+  // to move more than one unit, in order to visually move one unit.
+  function moveVisually(line, start, dir, byUnit) {
+    var bidi = getOrder(line);
+    if (!bidi) return moveLogically(line, start, dir, byUnit);
+    var pos = getBidiPartAt(bidi, start), part = bidi[pos];
+    var target = moveInLine(line, start, part.level % 2 ? -dir : dir, byUnit);
+
+    for (;;) {
+      if (target > part.from && target < part.to) return target;
+      if (target == part.from || target == part.to) {
+        if (getBidiPartAt(bidi, target) == pos) return target;
+        part = bidi[pos += dir];
+        return (dir > 0) == part.level % 2 ? part.to : part.from;
+      } else {
+        part = bidi[pos += dir];
+        if (!part) return null;
+        if ((dir > 0) == part.level % 2)
+          target = moveInLine(line, part.to, -1, byUnit);
+        else
+          target = moveInLine(line, part.from, 1, byUnit);
+      }
+    }
+  }
+
+  function moveLogically(line, start, dir, byUnit) {
+    var target = start + dir;
+    if (byUnit) while (target > 0 && isExtendingChar(line.text.charAt(target))) target += dir;
+    return target < 0 || target > line.text.length ? null : target;
+  }
+
+  // Bidirectional ordering algorithm
+  // See http://unicode.org/reports/tr9/tr9-13.html for the algorithm
+  // that this (partially) implements.
+
+  // One-char codes used for character types:
+  // L (L):   Left-to-Right
+  // R (R):   Right-to-Left
+  // r (AL):  Right-to-Left Arabic
+  // 1 (EN):  European Number
+  // + (ES):  European Number Separator
+  // % (ET):  European Number Terminator
+  // n (AN):  Arabic Number
+  // , (CS):  Common Number Separator
+  // m (NSM): Non-Spacing Mark
+  // b (BN):  Boundary Neutral
+  // s (B):   Paragraph Separator
+  // t (S):   Segment Separator
+  // w (WS):  Whitespace
+  // N (ON):  Other Neutrals
+
+  // Returns null if characters are ordered as they appear
+  // (left-to-right), or an array of sections ({from, to, level}
+  // objects) in the order in which they occur visually.
+  var bidiOrdering = (function() {
+    // Character types for codepoints 0 to 0xff
+    var lowTypes = "bbbbbbbbbtstwsbbbbbbbbbbbbbbssstwNN%%%NNNNNN,N,N1111111111NNNNNNNLLLLLLLLLLLLLLLLLLLLLLLLLLNNNNNNLLLLLLLLLLLLLLLLLLLLLLLLLLNNNNbbbbbbsbbbbbbbbbbbbbbbbbbbbbbbbbb,N%%%%NNNNLNNNNN%%11NLNNN1LNNNNNLLLLLLLLLLLLLLLLLLLLLLLNLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLN";
+    // Character types for codepoints 0x600 to 0x6ff
+    var arabicTypes = "rrrrrrrrrrrr,rNNmmmmmmrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrmmmmmmmmmmmmmmrrrrrrrnnnnnnnnnn%nnrrrmrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrmmmmmmmmmmmmmmmmmmmNmmmm";
+    function charType(code) {
+      if (code <= 0xf7) return lowTypes.charAt(code);
+      else if (0x590 <= code && code <= 0x5f4) return "R";
+      else if (0x600 <= code && code <= 0x6ed) return arabicTypes.charAt(code - 0x600);
+      else if (0x6ee <= code && code <= 0x8ac) return "r";
+      else if (0x2000 <= code && code <= 0x200b) return "w";
+      else if (code == 0x200c) return "b";
+      else return "L";
+    }
+
+    var bidiRE = /[\u0590-\u05f4\u0600-\u06ff\u0700-\u08ac]/;
+    var isNeutral = /[stwN]/, isStrong = /[LRr]/, countsAsLeft = /[Lb1n]/, countsAsNum = /[1n]/;
+    // Browsers seem to always treat the boundaries of block elements as being L.
+    var outerType = "L";
+
+    function BidiSpan(level, from, to) {
+      this.level = level;
+      this.from = from; this.to = to;
+    }
+
+    return function(str) {
+      if (!bidiRE.test(str)) return false;
+      var len = str.length, types = [];
+      for (var i = 0, type; i < len; ++i)
+        types.push(type = charType(str.charCodeAt(i)));
+
+      // W1. Examine each non-spacing mark (NSM) in the level run, and
+      // change the type of the NSM to the type of the previous
+      // character. If the NSM is at the start of the level run, it will
+      // get the type of sor.
+      for (var i = 0, prev = outerType; i < len; ++i) {
+        var type = types[i];
+        if (type == "m") types[i] = prev;
+        else prev = type;
+      }
+
+      // W2. Search backwards from each instance of a European number
+      // until the first strong type (R, L, AL, or sor) is found. If an
+      // AL is found, change the type of the European number to Arabic
+      // number.
+      // W3. Change all ALs to R.
+      for (var i = 0, cur = outerType; i < len; ++i) {
+        var type = types[i];
+        if (type == "1" && cur == "r") types[i] = "n";
+        else if (isStrong.test(type)) { cur = type; if (type == "r") types[i] = "R"; }
+      }
+
+      // W4. A single European separator between two European numbers
+      // changes to a European number. A single common separator between
+      // two numbers of the same type changes to that type.
+      for (var i = 1, prev = types[0]; i < len - 1; ++i) {
+        var type = types[i];
+        if (type == "+" && prev == "1" && types[i+1] == "1") types[i] = "1";
+        else if (type == "," && prev == types[i+1] &&
+                 (prev == "1" || prev == "n")) types[i] = prev;
+        prev = type;
+      }
+
+      // W5. A sequence of European terminators adjacent to European
+      // numbers changes to all European numbers.
+      // W6. Otherwise, separators and terminators change to Other
+      // Neutral.
+      for (var i = 0; i < len; ++i) {
+        var type = types[i];
+        if (type == ",") types[i] = "N";
+        else if (type == "%") {
+          for (var end = i + 1; end < len && types[end] == "%"; ++end) {}
+          var replace = (i && types[i-1] == "!") || (end < len && types[end] == "1") ? "1" : "N";
+          for (var j = i; j < end; ++j) types[j] = replace;
+          i = end - 1;
+        }
+      }
+
+      // W7. Search backwards from each instance of a European number
+      // until the first strong type (R, L, or sor) is found. If an L is
+      // found, then change the type of the European number to L.
+      for (var i = 0, cur = outerType; i < len; ++i) {
+        var type = types[i];
+        if (cur == "L" && type == "1") types[i] = "L";
+        else if (isStrong.test(type)) cur = type;
+      }
+
+      // N1. A sequence of neutrals takes the direction of the
+      // surrounding strong text if the text on both sides has the same
+      // direction. European and Arabic numbers act as if they were R in
+      // terms of their influence on neutrals. Start-of-level-run (sor)
+      // and end-of-level-run (eor) are used at level run boundaries.
+      // N2. Any remaining neutrals take the embedding direction.
+      for (var i = 0; i < len; ++i) {
+        if (isNeutral.test(types[i])) {
+          for (var end = i + 1; end < len && isNeutral.test(types[end]); ++end) {}
+          var before = (i ? types[i-1] : outerType) == "L";
+          var after = (end < len ? types[end] : outerType) == "L";
+          var replace = before || after ? "L" : "R";
+          for (var j = i; j < end; ++j) types[j] = replace;
+          i = end - 1;
+        }
+      }
+
+      // Here we depart from the documented algorithm, in order to avoid
+      // building up an actual levels array. Since there are only three
+      // levels (0, 1, 2) in an implementation that doesn't take
+      // explicit embedding into account, we can build up the order on
+      // the fly, without following the level-based algorithm.
+      var order = [], m;
+      for (var i = 0; i < len;) {
+        if (countsAsLeft.test(types[i])) {
+          var start = i;
+          for (++i; i < len && countsAsLeft.test(types[i]); ++i) {}
+          order.push(new BidiSpan(0, start, i));
+        } else {
+          var pos = i, at = order.length;
+          for (++i; i < len && types[i] != "L"; ++i) {}
+          for (var j = pos; j < i;) {
+            if (countsAsNum.test(types[j])) {
+              if (pos < j) order.splice(at, 0, new BidiSpan(1, pos, j));
+              var nstart = j;
+              for (++j; j < i && countsAsNum.test(types[j]); ++j) {}
+              order.splice(at, 0, new BidiSpan(2, nstart, j));
+              pos = j;
+            } else ++j;
+          }
+          if (pos < i) order.splice(at, 0, new BidiSpan(1, pos, i));
+        }
+      }
+      if (order[0].level == 1 && (m = str.match(/^\s+/))) {
+        order[0].from = m[0].length;
+        order.unshift(new BidiSpan(0, 0, m[0].length));
+      }
+      if (lst(order).level == 1 && (m = str.match(/\s+$/))) {
+        lst(order).to -= m[0].length;
+        order.push(new BidiSpan(0, len - m[0].length, len));
+      }
+      if (order[0].level == 2)
+        order.unshift(new BidiSpan(1, order[0].to, order[0].to));
+      if (order[0].level != lst(order).level)
+        order.push(new BidiSpan(order[0].level, len, len));
+
+      return order;
+    };
+  })();
+
+  // THE END
+
+  CodeMirror.version = "5.3.1";
+
+  return CodeMirror;
+});
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/static/codemirror/mode/xml/xml.js basex-8.2.3/basex-api/src/main/webapp/dba/static/codemirror/mode/xml/xml.js
--- basex-8.1.1/basex-api/src/main/webapp/dba/static/codemirror/mode/xml/xml.js	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/static/codemirror/mode/xml/xml.js	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,384 @@
+// CodeMirror, copyright (c) by Marijn Haverbeke and others
+// Distributed under an MIT license: http://codemirror.net/LICENSE
+
+(function(mod) {
+  if (typeof exports == "object" && typeof module == "object") // CommonJS
+    mod(require("../../lib/codemirror"));
+  else if (typeof define == "function" && define.amd) // AMD
+    define(["../../lib/codemirror"], mod);
+  else // Plain browser env
+    mod(CodeMirror);
+})(function(CodeMirror) {
+"use strict";
+
+CodeMirror.defineMode("xml", function(config, parserConfig) {
+  var indentUnit = config.indentUnit;
+  var multilineTagIndentFactor = parserConfig.multilineTagIndentFactor || 1;
+  var multilineTagIndentPastTag = parserConfig.multilineTagIndentPastTag;
+  if (multilineTagIndentPastTag == null) multilineTagIndentPastTag = true;
+
+  var Kludges = parserConfig.htmlMode ? {
+    autoSelfClosers: {'area': true, 'base': true, 'br': true, 'col': true, 'command': true,
+                      'embed': true, 'frame': true, 'hr': true, 'img': true, 'input': true,
+                      'keygen': true, 'link': true, 'meta': true, 'param': true, 'source': true,
+                      'track': true, 'wbr': true, 'menuitem': true},
+    implicitlyClosed: {'dd': true, 'li': true, 'optgroup': true, 'option': true, 'p': true,
+                       'rp': true, 'rt': true, 'tbody': true, 'td': true, 'tfoot': true,
+                       'th': true, 'tr': true},
+    contextGrabbers: {
+      'dd': {'dd': true, 'dt': true},
+      'dt': {'dd': true, 'dt': true},
+      'li': {'li': true},
+      'option': {'option': true, 'optgroup': true},
+      'optgroup': {'optgroup': true},
+      'p': {'address': true, 'article': true, 'aside': true, 'blockquote': true, 'dir': true,
+            'div': true, 'dl': true, 'fieldset': true, 'footer': true, 'form': true,
+            'h1': true, 'h2': true, 'h3': true, 'h4': true, 'h5': true, 'h6': true,
+            'header': true, 'hgroup': true, 'hr': true, 'menu': true, 'nav': true, 'ol': true,
+            'p': true, 'pre': true, 'section': true, 'table': true, 'ul': true},
+      'rp': {'rp': true, 'rt': true},
+      'rt': {'rp': true, 'rt': true},
+      'tbody': {'tbody': true, 'tfoot': true},
+      'td': {'td': true, 'th': true},
+      'tfoot': {'tbody': true},
+      'th': {'td': true, 'th': true},
+      'thead': {'tbody': true, 'tfoot': true},
+      'tr': {'tr': true}
+    },
+    doNotIndent: {"pre": true},
+    allowUnquoted: true,
+    allowMissing: true,
+    caseFold: true
+  } : {
+    autoSelfClosers: {},
+    implicitlyClosed: {},
+    contextGrabbers: {},
+    doNotIndent: {},
+    allowUnquoted: false,
+    allowMissing: false,
+    caseFold: false
+  };
+  var alignCDATA = parserConfig.alignCDATA;
+
+  // Return variables for tokenizers
+  var type, setStyle;
+
+  function inText(stream, state) {
+    function chain(parser) {
+      state.tokenize = parser;
+      return parser(stream, state);
+    }
+
+    var ch = stream.next();
+    if (ch == "<") {
+      if (stream.eat("!")) {
+        if (stream.eat("[")) {
+          if (stream.match("CDATA[")) return chain(inBlock("atom", "]]>"));
+          else return null;
+        } else if (stream.match("--")) {
+          return chain(inBlock("comment", "-->"));
+        } else if (stream.match("DOCTYPE", true, true)) {
+          stream.eatWhile(/[\w\._\-]/);
+          return chain(doctype(1));
+        } else {
+          return null;
+        }
+      } else if (stream.eat("?")) {
+        stream.eatWhile(/[\w\._\-]/);
+        state.tokenize = inBlock("meta", "?>");
+        return "meta";
+      } else {
+        type = stream.eat("/") ? "closeTag" : "openTag";
+        state.tokenize = inTag;
+        return "tag bracket";
+      }
+    } else if (ch == "&") {
+      var ok;
+      if (stream.eat("#")) {
+        if (stream.eat("x")) {
+          ok = stream.eatWhile(/[a-fA-F\d]/) && stream.eat(";");
+        } else {
+          ok = stream.eatWhile(/[\d]/) && stream.eat(";");
+        }
+      } else {
+        ok = stream.eatWhile(/[\w\.\-:]/) && stream.eat(";");
+      }
+      return ok ? "atom" : "error";
+    } else {
+      stream.eatWhile(/[^&<]/);
+      return null;
+    }
+  }
+
+  function inTag(stream, state) {
+    var ch = stream.next();
+    if (ch == ">" || (ch == "/" && stream.eat(">"))) {
+      state.tokenize = inText;
+      type = ch == ">" ? "endTag" : "selfcloseTag";
+      return "tag bracket";
+    } else if (ch == "=") {
+      type = "equals";
+      return null;
+    } else if (ch == "<") {
+      state.tokenize = inText;
+      state.state = baseState;
+      state.tagName = state.tagStart = null;
+      var next = state.tokenize(stream, state);
+      return next ? next + " tag error" : "tag error";
+    } else if (/[\'\"]/.test(ch)) {
+      state.tokenize = inAttribute(ch);
+      state.stringStartCol = stream.column();
+      return state.tokenize(stream, state);
+    } else {
+      stream.match(/^[^\s\u00a0=<>\"\']*[^\s\u00a0=<>\"\'\/]/);
+      return "word";
+    }
+  }
+
+  function inAttribute(quote) {
+    var closure = function(stream, state) {
+      while (!stream.eol()) {
+        if (stream.next() == quote) {
+          state.tokenize = inTag;
+          break;
+        }
+      }
+      return "string";
+    };
+    closure.isInAttribute = true;
+    return closure;
+  }
+
+  function inBlock(style, terminator) {
+    return function(stream, state) {
+      while (!stream.eol()) {
+        if (stream.match(terminator)) {
+          state.tokenize = inText;
+          break;
+        }
+        stream.next();
+      }
+      return style;
+    };
+  }
+  function doctype(depth) {
+    return function(stream, state) {
+      var ch;
+      while ((ch = stream.next()) != null) {
+        if (ch == "<") {
+          state.tokenize = doctype(depth + 1);
+          return state.tokenize(stream, state);
+        } else if (ch == ">") {
+          if (depth == 1) {
+            state.tokenize = inText;
+            break;
+          } else {
+            state.tokenize = doctype(depth - 1);
+            return state.tokenize(stream, state);
+          }
+        }
+      }
+      return "meta";
+    };
+  }
+
+  function Context(state, tagName, startOfLine) {
+    this.prev = state.context;
+    this.tagName = tagName;
+    this.indent = state.indented;
+    this.startOfLine = startOfLine;
+    if (Kludges.doNotIndent.hasOwnProperty(tagName) || (state.context && state.context.noIndent))
+      this.noIndent = true;
+  }
+  function popContext(state) {
+    if (state.context) state.context = state.context.prev;
+  }
+  function maybePopContext(state, nextTagName) {
+    var parentTagName;
+    while (true) {
+      if (!state.context) {
+        return;
+      }
+      parentTagName = state.context.tagName;
+      if (!Kludges.contextGrabbers.hasOwnProperty(parentTagName) ||
+          !Kludges.contextGrabbers[parentTagName].hasOwnProperty(nextTagName)) {
+        return;
+      }
+      popContext(state);
+    }
+  }
+
+  function baseState(type, stream, state) {
+    if (type == "openTag") {
+      state.tagStart = stream.column();
+      return tagNameState;
+    } else if (type == "closeTag") {
+      return closeTagNameState;
+    } else {
+      return baseState;
+    }
+  }
+  function tagNameState(type, stream, state) {
+    if (type == "word") {
+      state.tagName = stream.current();
+      setStyle = "tag";
+      return attrState;
+    } else {
+      setStyle = "error";
+      return tagNameState;
+    }
+  }
+  function closeTagNameState(type, stream, state) {
+    if (type == "word") {
+      var tagName = stream.current();
+      if (state.context && state.context.tagName != tagName &&
+          Kludges.implicitlyClosed.hasOwnProperty(state.context.tagName))
+        popContext(state);
+      if (state.context && state.context.tagName == tagName) {
+        setStyle = "tag";
+        return closeState;
+      } else {
+        setStyle = "tag error";
+        return closeStateErr;
+      }
+    } else {
+      setStyle = "error";
+      return closeStateErr;
+    }
+  }
+
+  function closeState(type, _stream, state) {
+    if (type != "endTag") {
+      setStyle = "error";
+      return closeState;
+    }
+    popContext(state);
+    return baseState;
+  }
+  function closeStateErr(type, stream, state) {
+    setStyle = "error";
+    return closeState(type, stream, state);
+  }
+
+  function attrState(type, _stream, state) {
+    if (type == "word") {
+      setStyle = "attribute";
+      return attrEqState;
+    } else if (type == "endTag" || type == "selfcloseTag") {
+      var tagName = state.tagName, tagStart = state.tagStart;
+      state.tagName = state.tagStart = null;
+      if (type == "selfcloseTag" ||
+          Kludges.autoSelfClosers.hasOwnProperty(tagName)) {
+        maybePopContext(state, tagName);
+      } else {
+        maybePopContext(state, tagName);
+        state.context = new Context(state, tagName, tagStart == state.indented);
+      }
+      return baseState;
+    }
+    setStyle = "error";
+    return attrState;
+  }
+  function attrEqState(type, stream, state) {
+    if (type == "equals") return attrValueState;
+    if (!Kludges.allowMissing) setStyle = "error";
+    return attrState(type, stream, state);
+  }
+  function attrValueState(type, stream, state) {
+    if (type == "string") return attrContinuedState;
+    if (type == "word" && Kludges.allowUnquoted) {setStyle = "string"; return attrState;}
+    setStyle = "error";
+    return attrState(type, stream, state);
+  }
+  function attrContinuedState(type, stream, state) {
+    if (type == "string") return attrContinuedState;
+    return attrState(type, stream, state);
+  }
+
+  return {
+    startState: function() {
+      return {tokenize: inText,
+              state: baseState,
+              indented: 0,
+              tagName: null, tagStart: null,
+              context: null};
+    },
+
+    token: function(stream, state) {
+      if (!state.tagName && stream.sol())
+        state.indented = stream.indentation();
+
+      if (stream.eatSpace()) return null;
+      type = null;
+      var style = state.tokenize(stream, state);
+      if ((style || type) && style != "comment") {
+        setStyle = null;
+        state.state = state.state(type || style, stream, state);
+        if (setStyle)
+          style = setStyle == "error" ? style + " error" : setStyle;
+      }
+      return style;
+    },
+
+    indent: function(state, textAfter, fullLine) {
+      var context = state.context;
+      // Indent multi-line strings (e.g. css).
+      if (state.tokenize.isInAttribute) {
+        if (state.tagStart == state.indented)
+          return state.stringStartCol + 1;
+        else
+          return state.indented + indentUnit;
+      }
+      if (context && context.noIndent) return CodeMirror.Pass;
+      if (state.tokenize != inTag && state.tokenize != inText)
+        return fullLine ? fullLine.match(/^(\s*)/)[0].length : 0;
+      // Indent the starts of attribute names.
+      if (state.tagName) {
+        if (multilineTagIndentPastTag)
+          return state.tagStart + state.tagName.length + 2;
+        else
+          return state.tagStart + indentUnit * multilineTagIndentFactor;
+      }
+      if (alignCDATA && /<!\[CDATA\[/.test(textAfter)) return 0;
+      var tagAfter = textAfter && /^<(\/)?([\w_:\.-]*)/.exec(textAfter);
+      if (tagAfter && tagAfter[1]) { // Closing tag spotted
+        while (context) {
+          if (context.tagName == tagAfter[2]) {
+            context = context.prev;
+            break;
+          } else if (Kludges.implicitlyClosed.hasOwnProperty(context.tagName)) {
+            context = context.prev;
+          } else {
+            break;
+          }
+        }
+      } else if (tagAfter) { // Opening tag spotted
+        while (context) {
+          var grabbers = Kludges.contextGrabbers[context.tagName];
+          if (grabbers && grabbers.hasOwnProperty(tagAfter[2]))
+            context = context.prev;
+          else
+            break;
+        }
+      }
+      while (context && !context.startOfLine)
+        context = context.prev;
+      if (context) return context.indent + indentUnit;
+      else return 0;
+    },
+
+    electricInput: /<\/[\s\w:]+>$/,
+    blockCommentStart: "<!--",
+    blockCommentEnd: "-->",
+
+    configuration: parserConfig.htmlMode ? "html" : "xml",
+    helperType: parserConfig.htmlMode ? "html" : "xml"
+  };
+});
+
+CodeMirror.defineMIME("text/xml", "xml");
+CodeMirror.defineMIME("application/xml", "xml");
+if (!CodeMirror.mimeModes.hasOwnProperty("text/html"))
+  CodeMirror.defineMIME("text/html", {name: "xml", htmlMode: true});
+
+});
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/static/codemirror/mode/xquery/xquery.js basex-8.2.3/basex-api/src/main/webapp/dba/static/codemirror/mode/xquery/xquery.js
--- basex-8.1.1/basex-api/src/main/webapp/dba/static/codemirror/mode/xquery/xquery.js	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/static/codemirror/mode/xquery/xquery.js	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,437 @@
+// CodeMirror, copyright (c) by Marijn Haverbeke and others
+// Distributed under an MIT license: http://codemirror.net/LICENSE
+
+(function(mod) {
+  if (typeof exports == "object" && typeof module == "object") // CommonJS
+    mod(require("../../lib/codemirror"));
+  else if (typeof define == "function" && define.amd) // AMD
+    define(["../../lib/codemirror"], mod);
+  else // Plain browser env
+    mod(CodeMirror);
+})(function(CodeMirror) {
+"use strict";
+
+CodeMirror.defineMode("xquery", function() {
+
+  // The keywords object is set to the result of this self executing
+  // function. Each keyword is a property of the keywords object whose
+  // value is {type: atype, style: astyle}
+  var keywords = function(){
+    // conveinence functions used to build keywords object
+    function kw(type) {return {type: type, style: "keyword"};}
+    var A = kw("keyword a")
+      , B = kw("keyword b")
+      , C = kw("keyword c")
+      , operator = kw("operator")
+      , atom = {type: "atom", style: "atom"}
+      , punctuation = {type: "punctuation", style: null}
+      , qualifier = {type: "axis_specifier", style: "qualifier"};
+
+    // kwObj is what is return from this function at the end
+    var kwObj = {
+      'if': A, 'switch': A, 'while': A, 'for': A,
+      'else': B, 'then': B, 'try': B, 'finally': B, 'catch': B,
+      'element': C, 'attribute': C, 'let': C, 'implements': C, 'import': C, 'module': C, 'namespace': C,
+      'return': C, 'super': C, 'this': C, 'throws': C, 'where': C, 'private': C,
+      ',': punctuation,
+      'null': atom, 'fn:false()': atom, 'fn:true()': atom
+    };
+
+    // a list of 'basic' keywords. For each add a property to kwObj with the value of
+    // {type: basic[i], style: "keyword"} e.g. 'after' --> {type: "after", style: "keyword"}
+    var basic = ['after','ancestor','ancestor-or-self','and','as','ascending','assert','attribute','before',
+    'by','case','cast','child','comment','declare','default','define','descendant','descendant-or-self',
+    'descending','document','document-node','element','else','eq','every','except','external','following',
+    'following-sibling','follows','for','function','if','import','in','instance','intersect','item',
+    'let','module','namespace','node','node','of','only','or','order','parent','precedes','preceding',
+    'preceding-sibling','processing-instruction','ref','return','returns','satisfies','schema','schema-element',
+    'self','some','sortby','stable','text','then','to','treat','typeswitch','union','variable','version','where',
+    'xquery', 'empty-sequence'];
+    for(var i=0, l=basic.length; i < l; i++) { kwObj[basic[i]] = kw(basic[i]);};
+
+    // a list of types. For each add a property to kwObj with the value of
+    // {type: "atom", style: "atom"}
+    var types = ['xs:string', 'xs:float', 'xs:decimal', 'xs:double', 'xs:integer', 'xs:boolean', 'xs:date', 'xs:dateTime',
+    'xs:time', 'xs:duration', 'xs:dayTimeDuration', 'xs:time', 'xs:yearMonthDuration', 'numeric', 'xs:hexBinary',
+    'xs:base64Binary', 'xs:anyURI', 'xs:QName', 'xs:byte','xs:boolean','xs:anyURI','xf:yearMonthDuration'];
+    for(var i=0, l=types.length; i < l; i++) { kwObj[types[i]] = atom;};
+
+    // each operator will add a property to kwObj with value of {type: "operator", style: "keyword"}
+    var operators = ['eq', 'ne', 'lt', 'le', 'gt', 'ge', ':=', '=', '>', '>=', '<', '<=', '.', '|', '?', 'and', 'or', 'div', 'idiv', 'mod', '*', '/', '+', '-'];
+    for(var i=0, l=operators.length; i < l; i++) { kwObj[operators[i]] = operator;};
+
+    // each axis_specifiers will add a property to kwObj with value of {type: "axis_specifier", style: "qualifier"}
+    var axis_specifiers = ["self::", "attribute::", "child::", "descendant::", "descendant-or-self::", "parent::",
+    "ancestor::", "ancestor-or-self::", "following::", "preceding::", "following-sibling::", "preceding-sibling::"];
+    for(var i=0, l=axis_specifiers.length; i < l; i++) { kwObj[axis_specifiers[i]] = qualifier; };
+
+    return kwObj;
+  }();
+
+  function chain(stream, state, f) {
+    state.tokenize = f;
+    return f(stream, state);
+  }
+
+  // the primary mode tokenizer
+  function tokenBase(stream, state) {
+    var ch = stream.next(),
+        mightBeFunction = false,
+        isEQName = isEQNameAhead(stream);
+
+    // an XML tag (if not in some sub, chained tokenizer)
+    if (ch == "<") {
+      if(stream.match("!--", true))
+        return chain(stream, state, tokenXMLComment);
+
+      if(stream.match("![CDATA", false)) {
+        state.tokenize = tokenCDATA;
+        return "tag";
+      }
+
+      if(stream.match("?", false)) {
+        return chain(stream, state, tokenPreProcessing);
+      }
+
+      var isclose = stream.eat("/");
+      stream.eatSpace();
+      var tagName = "", c;
+      while ((c = stream.eat(/[^\s\u00a0=<>\"\'\/?]/))) tagName += c;
+
+      return chain(stream, state, tokenTag(tagName, isclose));
+    }
+    // start code block
+    else if(ch == "{") {
+      pushStateStack(state,{ type: "codeblock"});
+      return null;
+    }
+    // end code block
+    else if(ch == "}") {
+      popStateStack(state);
+      return null;
+    }
+    // if we're in an XML block
+    else if(isInXmlBlock(state)) {
+      if(ch == ">")
+        return "tag";
+      else if(ch == "/" && stream.eat(">")) {
+        popStateStack(state);
+        return "tag";
+      }
+      else
+        return "variable";
+    }
+    // if a number
+    else if (/\d/.test(ch)) {
+      stream.match(/^\d*(?:\.\d*)?(?:E[+\-]?\d+)?/);
+      return "atom";
+    }
+    // comment start
+    else if (ch === "(" && stream.eat(":")) {
+      pushStateStack(state, { type: "comment"});
+      return chain(stream, state, tokenComment);
+    }
+    // quoted string
+    else if (  !isEQName && (ch === '"' || ch === "'"))
+      return chain(stream, state, tokenString(ch));
+    // variable
+    else if(ch === "$") {
+      return chain(stream, state, tokenVariable);
+    }
+    // assignment
+    else if(ch ===":" && stream.eat("=")) {
+      return "keyword";
+    }
+    // open paren
+    else if(ch === "(") {
+      pushStateStack(state, { type: "paren"});
+      return null;
+    }
+    // close paren
+    else if(ch === ")") {
+      popStateStack(state);
+      return null;
+    }
+    // open paren
+    else if(ch === "[") {
+      pushStateStack(state, { type: "bracket"});
+      return null;
+    }
+    // close paren
+    else if(ch === "]") {
+      popStateStack(state);
+      return null;
+    }
+    else {
+      var known = keywords.propertyIsEnumerable(ch) && keywords[ch];
+
+      // if there's a EQName ahead, consume the rest of the string portion, it's likely a function
+      if(isEQName && ch === '\"') while(stream.next() !== '"'){}
+      if(isEQName && ch === '\'') while(stream.next() !== '\''){}
+
+      // gobble up a word if the character is not known
+      if(!known) stream.eatWhile(/[\w\$_-]/);
+
+      // gobble a colon in the case that is a lib func type call fn:doc
+      var foundColon = stream.eat(":");
+
+      // if there's not a second colon, gobble another word. Otherwise, it's probably an axis specifier
+      // which should get matched as a keyword
+      if(!stream.eat(":") && foundColon) {
+        stream.eatWhile(/[\w\$_-]/);
+      }
+      // if the next non whitespace character is an open paren, this is probably a function (if not a keyword of other sort)
+      if(stream.match(/^[ \t]*\(/, false)) {
+        mightBeFunction = true;
+      }
+      // is the word a keyword?
+      var word = stream.current();
+      known = keywords.propertyIsEnumerable(word) && keywords[word];
+
+      // if we think it's a function call but not yet known,
+      // set style to variable for now for lack of something better
+      if(mightBeFunction && !known) known = {type: "function_call", style: "variable def"};
+
+      // if the previous word was element, attribute, axis specifier, this word should be the name of that
+      if(isInXmlConstructor(state)) {
+        popStateStack(state);
+        return "variable";
+      }
+      // as previously checked, if the word is element,attribute, axis specifier, call it an "xmlconstructor" and
+      // push the stack so we know to look for it on the next word
+      if(word == "element" || word == "attribute" || known.type == "axis_specifier") pushStateStack(state, {type: "xmlconstructor"});
+
+      // if the word is known, return the details of that else just call this a generic 'word'
+      return known ? known.style : "variable";
+    }
+  }
+
+  // handle comments, including nested
+  function tokenComment(stream, state) {
+    var maybeEnd = false, maybeNested = false, nestedCount = 0, ch;
+    while (ch = stream.next()) {
+      if (ch == ")" && maybeEnd) {
+        if(nestedCount > 0)
+          nestedCount--;
+        else {
+          popStateStack(state);
+          break;
+        }
+      }
+      else if(ch == ":" && maybeNested) {
+        nestedCount++;
+      }
+      maybeEnd = (ch == ":");
+      maybeNested = (ch == "(");
+    }
+
+    return "comment";
+  }
+
+  // tokenizer for string literals
+  // optionally pass a tokenizer function to set state.tokenize back to when finished
+  function tokenString(quote, f) {
+    return function(stream, state) {
+      var ch;
+
+      if(isInString(state) && stream.current() == quote) {
+        popStateStack(state);
+        if(f) state.tokenize = f;
+        return "string";
+      }
+
+      pushStateStack(state, { type: "string", name: quote, tokenize: tokenString(quote, f) });
+
+      // if we're in a string and in an XML block, allow an embedded code block
+      if(stream.match("{", false) && isInXmlAttributeBlock(state)) {
+        state.tokenize = tokenBase;
+        return "string";
+      }
+
+
+      while (ch = stream.next()) {
+        if (ch ==  quote) {
+          popStateStack(state);
+          if(f) state.tokenize = f;
+          break;
+        }
+        else {
+          // if we're in a string and in an XML block, allow an embedded code block in an attribute
+          if(stream.match("{", false) && isInXmlAttributeBlock(state)) {
+            state.tokenize = tokenBase;
+            return "string";
+          }
+
+        }
+      }
+
+      return "string";
+    };
+  }
+
+  // tokenizer for variables
+  function tokenVariable(stream, state) {
+    var isVariableChar = /[\w\$_-]/;
+
+    // a variable may start with a quoted EQName so if the next character is quote, consume to the next quote
+    if(stream.eat("\"")) {
+      while(stream.next() !== '\"'){};
+      stream.eat(":");
+    } else {
+      stream.eatWhile(isVariableChar);
+      if(!stream.match(":=", false)) stream.eat(":");
+    }
+    stream.eatWhile(isVariableChar);
+    state.tokenize = tokenBase;
+    return "variable";
+  }
+
+  // tokenizer for XML tags
+  function tokenTag(name, isclose) {
+    return function(stream, state) {
+      stream.eatSpace();
+      if(isclose && stream.eat(">")) {
+        popStateStack(state);
+        state.tokenize = tokenBase;
+        return "tag";
+      }
+      // self closing tag without attributes?
+      if(!stream.eat("/"))
+        pushStateStack(state, { type: "tag", name: name, tokenize: tokenBase});
+      if(!stream.eat(">")) {
+        state.tokenize = tokenAttribute;
+        return "tag";
+      }
+      else {
+        state.tokenize = tokenBase;
+      }
+      return "tag";
+    };
+  }
+
+  // tokenizer for XML attributes
+  function tokenAttribute(stream, state) {
+    var ch = stream.next();
+
+    if(ch == "/" && stream.eat(">")) {
+      if(isInXmlAttributeBlock(state)) popStateStack(state);
+      if(isInXmlBlock(state)) popStateStack(state);
+      return "tag";
+    }
+    if(ch == ">") {
+      if(isInXmlAttributeBlock(state)) popStateStack(state);
+      return "tag";
+    }
+    if(ch == "=")
+      return null;
+    // quoted string
+    if (ch == '"' || ch == "'")
+      return chain(stream, state, tokenString(ch, tokenAttribute));
+
+    if(!isInXmlAttributeBlock(state))
+      pushStateStack(state, { type: "attribute", tokenize: tokenAttribute});
+
+    stream.eat(/[a-zA-Z_:]/);
+    stream.eatWhile(/[-a-zA-Z0-9_:.]/);
+    stream.eatSpace();
+
+    // the case where the attribute has not value and the tag was closed
+    if(stream.match(">", false) || stream.match("/", false)) {
+      popStateStack(state);
+      state.tokenize = tokenBase;
+    }
+
+    return "attribute";
+  }
+
+  // handle comments, including nested
+  function tokenXMLComment(stream, state) {
+    var ch;
+    while (ch = stream.next()) {
+      if (ch == "-" && stream.match("->", true)) {
+        state.tokenize = tokenBase;
+        return "comment";
+      }
+    }
+  }
+
+
+  // handle CDATA
+  function tokenCDATA(stream, state) {
+    var ch;
+    while (ch = stream.next()) {
+      if (ch == "]" && stream.match("]", true)) {
+        state.tokenize = tokenBase;
+        return "comment";
+      }
+    }
+  }
+
+  // handle preprocessing instructions
+  function tokenPreProcessing(stream, state) {
+    var ch;
+    while (ch = stream.next()) {
+      if (ch == "?" && stream.match(">", true)) {
+        state.tokenize = tokenBase;
+        return "comment meta";
+      }
+    }
+  }
+
+
+  // functions to test the current context of the state
+  function isInXmlBlock(state) { return isIn(state, "tag"); }
+  function isInXmlAttributeBlock(state) { return isIn(state, "attribute"); }
+  function isInXmlConstructor(state) { return isIn(state, "xmlconstructor"); }
+  function isInString(state) { return isIn(state, "string"); }
+
+  function isEQNameAhead(stream) {
+    // assume we've already eaten a quote (")
+    if(stream.current() === '"')
+      return stream.match(/^[^\"]+\"\:/, false);
+    else if(stream.current() === '\'')
+      return stream.match(/^[^\"]+\'\:/, false);
+    else
+      return false;
+  }
+
+  function isIn(state, type) {
+    return (state.stack.length && state.stack[state.stack.length - 1].type == type);
+  }
+
+  function pushStateStack(state, newState) {
+    state.stack.push(newState);
+  }
+
+  function popStateStack(state) {
+    state.stack.pop();
+    var reinstateTokenize = state.stack.length && state.stack[state.stack.length-1].tokenize;
+    state.tokenize = reinstateTokenize || tokenBase;
+  }
+
+  // the interface for the mode API
+  return {
+    startState: function() {
+      return {
+        tokenize: tokenBase,
+        cc: [],
+        stack: []
+      };
+    },
+
+    token: function(stream, state) {
+      if (stream.eatSpace()) return null;
+      var style = state.tokenize(stream, state);
+      return style;
+    },
+
+    blockCommentStart: "(:",
+    blockCommentEnd: ":)"
+
+  };
+
+});
+
+CodeMirror.defineMIME("application/xquery", "xquery");
+
+});
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/static/editor.js basex-8.2.3/basex-api/src/main/webapp/dba/static/editor.js
--- basex-8.1.1/basex-api/src/main/webapp/dba/static/editor.js	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/static/editor.js	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,124 @@
+function openQuery() {
+  var file = document.getElementById("file");
+  request("POST", "open-query?name=" + encodeURIComponent(file.value.trim()),
+    null,
+    function(req) {
+      document.getElementById("editor").value = req.responseText;
+      var evt = document.createEvent("HTMLEvents");
+      evt.initEvent("change",false,false);
+      document.getElementById("editor").dispatchEvent(evt);
+    },
+    function(req) {
+      setError('Query could not be opened.');
+    }
+  )
+};
+
+function saveQuery() {
+  if(queryExists() && !confirm('Overwrite existing query?')) return;
+
+  var file = document.getElementById("file");
+  request("POST", "save-query?name=" + encodeURIComponent(file.value.trim()),
+    document.getElementById("editor").value,
+    function(req) {
+      refreshDataList(req);
+      setInfo("Query was saved.");
+    },
+    function(req) {
+      setError("Query could not be saved.");
+    }
+  )
+};
+
+function deleteQuery() {
+  if(!confirm('Are you sure?')) return;
+
+  var file = document.getElementById("file");
+  request("POST", "delete-query?name=" + encodeURIComponent(file.value.trim()),
+    null,
+    function(req) {
+      refreshDataList(req);
+      setInfo("Query was deleted");
+      file.value = "";
+    },
+    function(req) {
+      setError("Query could not be deleted.");
+    }
+  )
+};
+
+function refreshDataList(req) {
+  var files = document.getElementById("files");
+  while(files.firstChild) {
+    files.removeChild(files.firstChild);
+  }
+  var names = req.responseText.split('/');
+  for (var i = 0; i < names.length; i++) {
+    var opt = document.createElement('option');
+    opt.value = names[i];
+    files.appendChild(opt);
+  }
+  checkButtons();
+};
+
+function checkButtons() {
+  var file = document.getElementById("file").value.trim();
+  document.getElementById("save").disabled = file.length == 0;
+  var disable = !queryExists();
+  document.getElementById("open").disabled = disable;
+  document.getElementById("delete").disabled = disable;
+};
+
+function queryExists() {
+  var file = document.getElementById("file").value.trim();
+  var files = document.getElementById("files").children;
+  for (var i = 0; i < files.length; i++) {
+    if(files[i].value == file) return true;
+  }
+  return false;
+};
+
+function loadCodeMirror() {
+  if (CodeMirror && dispatchEvent) {
+    //Now replace the editor and result areas
+    var editorArea = document.getElementById("editor");
+    var codeMirrorEditor = CodeMirror.fromTextArea(editorArea, {
+      mode: "xquery",
+      lineNumbers: true,
+      extraKeys: {
+        "Ctrl-Enter": function(cm) {
+           editor("Please wait…", "Query was successful.", true);
+        },
+        "Cmd-Enter": function(cm) {
+           editor("Please wait…", "Query was successful.", true);
+        }
+      }
+    });
+    codeMirrorEditor.on("change",function(cm, cmo) {
+        cm.save();
+        editor("Please wait…", "Query was successful.", false);
+      }
+    );
+    codeMirrorEditor.display.wrapper.style.border = "solid 1pt black";
+    editorArea.addEventListener("change",function() {
+      codeMirrorEditor.setValue(editorArea.value);
+    });
+    var outputArea = document.getElementById("output");
+    var codeMirrorResult = CodeMirror.fromTextArea(outputArea, {mode: "xml"});
+    codeMirrorResult.display.wrapper.style.border = "solid 1pt black";
+    outputArea.addEventListener("change",function() {codeMirrorResult.setValue(outputArea.value)});
+    window.addEventListener("load",setDisplayHeight);
+    window.addEventListener("resize",setDisplayHeight);
+  }
+}
+
+function setDisplayHeight() {
+  var elem = document.createElement("div");
+  document.body.appendChild(elem);
+  p = elem.offsetTop + 48 //To account for margin, it works but is not bullet proof.
+  var c = document.getElementsByClassName("CodeMirror")[0].offsetHeight;
+  var s = window.innerHeight;
+  Array.prototype.forEach.call(document.getElementsByClassName("CodeMirror"),function(cm) {
+    cm.CodeMirror.setSize("100%",Math.max(200,s-(p-c)));
+  });
+}
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/static/js.js basex-8.2.3/basex-api/src/main/webapp/dba/static/js.js
--- basex-8.1.1/basex-api/src/main/webapp/dba/static/js.js	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/static/js.js	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,155 @@
+function buttons() {
+  var forms = document.getElementsByTagName("form");
+  for(var f = 0; f < forms.length; f++) {
+    var form = forms[f];
+    if(form.className != 'update') continue;
+
+    var inputs = form.getElementsByTagName("input");
+    var c = 0;
+    for(var i = 0; i < inputs.length; i++) {
+      if(inputs[i].type == "checkbox" && inputs[i].checked) c++;
+    }
+    var buttons = form.getElementsByTagName("button");
+    for(var i = 0; i < buttons.length; i++) {
+      var button = buttons[i], n = button.className, s = button.value, e = !button.disabled;
+      if(n == 'global') continue;
+
+      if(s == "optimize" || s == "optimize-all" || s == "drop-backup" ||
+         s == "drop-db" || s == "drop-pattern" || s == "drop-user" ||
+         s == "kill-session" || s == "restore" || s == "backup" || s == "delete" ||
+         s == "delete-files" || s == "delete-logs" || s == "kill") {
+        e = c > 0;
+      }
+      button.disabled = !e;
+    }
+  }
+};
+
+function setInfo(message) {
+  setText(message, 'info');
+};
+
+function setWarning(message) {
+  setText(message, 'warning');
+};
+
+function setError(message) {
+  setText(message.replace(/Stack Trace:.*/, ''), 'error');
+};
+
+function setText(message, type) {
+  var i = document.getElementById("info");
+  i.className = type;
+  i.textContent = message;
+};
+
+var searchDelay = 200;
+var _d;
+function query(wait, success, key, query, enforce, target) {
+  var d = new Date();
+  _d = d;
+  setTimeout(function() {
+    if(_d != d) return;
+    if(wait) setWarning(wait);
+
+    var name = document.getElementById("name");
+    var resource = document.getElementById("resource");
+    var sort = document.getElementById("sort");
+    var loglist = document.getElementById("loglist");
+    var url = key +
+      "?name=" + encodeURIComponent(name ? name.value : "") +
+      "&resource=" + encodeURIComponent(resource ? resource.value : "") +
+      "&sort=" + encodeURIComponent(sort ? sort.value : "") +
+      "&loglist=" + encodeURIComponent(loglist ? loglist.value : "");
+    request("POST", url, query,
+      function(req) {
+        if(_d != d) return;
+        target(req.responseText);
+        if(success) setInfo(success);
+      },
+      function(req) {
+        if(_d != d) return;
+        setErrorFromResponse(req);
+      }
+    )
+  }, enforce ? 0 : searchDelay);
+};
+
+// Jetty and Tomcat support (both return error messages differently)
+function setErrorFromResponse(req) {
+  var msg = req.statusText.match(/\[\w+\]/g) ? req.statusText : req.responseText;
+  var s = msg.indexOf('['), e1 = msg.indexOf('\n', s), e2 = msg.indexOf('<', s);
+  if(s > -1) msg = msg.substring(s, e1 > e2 ? e2 : e1 > s ? e1 : msg.length);
+  var html = document.createElement('div');
+  html.innerHTML = msg;
+  setError(html.innerText || html.textContent);
+};
+
+var _list;
+function logslist(wait, success) {
+  var input = document.getElementById('loglist').value.trim();
+  if(_list == input) return false;
+  _list = input;
+  query(wait, success, 'loglist', input, false, function(text) {
+    document.getElementById("list").innerHTML = text;
+  })
+};
+
+var _logs;
+function logentries(wait, success) {
+  var input = document.getElementById('logs').value.trim();
+  if(_logs == input) return false;
+  _logs = input;
+  query(wait, success, 'log', input, false, function(text) {
+    document.getElementById("output").innerHTML = text;
+  });
+};
+
+var _input;
+function queryResource(wait, success) {
+  var input = document.getElementById('input').value.trim();
+  if(_input == input) return false;
+  _input = input;
+  var target = 'query-resource';
+  var enforce = false;
+  query(wait, success, target, input, enforce, function(text) {
+    document.getElementById("output").value = text;
+  });
+};
+
+var _editor;
+function editor(wait, success, enforce) {
+  var mode = document.getElementById("mode").selectedIndex;
+  var update = mode == 2;
+  var realtime = mode == 1;
+  document.getElementById("run").disabled = realtime;
+
+  var editor = document.getElementById('editor').value;
+  if(enforce || (realtime && _editor != editor)) {
+    _editor = editor;
+    var target = update ? 'update-query' : 'eval-query';
+    query(wait, success, target, editor, enforce, function(text) {
+      document.getElementById("output").value = text;
+      var evt = document.createEvent("HTMLEvents");
+      evt.initEvent("change",false,false);
+      document.getElementById("output").dispatchEvent(evt);
+    });
+  }
+};
+
+function request(method, url, data, success, failure) {
+  var req = window.XMLHttpRequest ? new XMLHttpRequest() : new ActiveXObject("Microsoft.XMLHTTP");
+  req.onreadystatechange = function() {
+    if(req.readyState == 4) {
+      if(req.status == 200) {
+        success(req);
+      } else {
+        failure(req);
+      }
+    }
+  };
+  // synchronous querying: wait for server feedback
+  req.open(method, url, true);
+  req.setRequestHeader("Content-Type", "text/plain");
+  req.send(data);
+};
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/static/style.css basex-8.2.3/basex-api/src/main/webapp/dba/static/style.css
--- basex-8.1.1/basex-api/src/main/webapp/dba/static/style.css	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/static/style.css	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,142 @@
+body {
+  font-family: Calibri, "Trebuchet MS", sans-serif;
+  overflow-y: scroll;
+  margin: 1em;
+  font-size: 16px;
+}
+
+ul, dd {
+  padding-left: 1.2em;
+  margin-left: 0;
+}
+
+dl {
+  margin: 0;
+}
+
+dt {
+  margin: 0.6em 0 0.6em 0;
+  font-weight: bold;
+}
+
+table {
+  font-size: 100%;
+  padding: 0;
+  border: 0;
+  table-layout: fixed;
+}
+
+th {
+  padding: 0 1.2em .2em 0;
+}
+
+td {
+  padding: 0 1.2em 0 0;
+  vertical-align: top;
+  border: 0;
+}
+
+textarea {
+  font-family: "Consolas", "Ubuntu Mono", monospace;
+  font-size: 90%;
+  margin: 4px 0px 4px 0px;
+  width: 100%;
+}
+
+select {
+  width: 166;
+}
+
+code {
+  font-family: "Consolas", "Ubuntu Mono", monospace;
+  border: 1px solid #E3E3FF;
+  border-radius: 3px;
+  padding: 0 4px 0 4px;
+  margin: 0 2px 0 2px;
+  font-size: 90%;
+}
+
+pre {
+  font-family: "Consolas", "Ubuntu Mono", monospace;
+  font-size: 90%;
+}
+
+h1 {
+  font-size: 220%;
+  font-weight: bold;
+  color: #AA1818;
+  margin: -2px 0 0 0;
+}
+
+h2 {
+  font-size: 150%;
+  color: #CC3333;
+  margin: 0 0 0.2em 0;
+}
+
+h3 {
+  font-size: 120%;
+  color: #CC3333;
+  margin: 0.2em 0 0.2em 0;
+}
+
+h4 {
+  font-size: 100%;
+  margin: 0 0 0.4em 0;
+}
+
+hr {
+  height: 1px;
+  border: 0px;
+  background-color: #777;
+}
+
+a {
+  color: #CC3333;
+  text-decoration: none;
+}
+
+a:hover {
+  text-decoration:underline;
+}
+
+p {
+  margin: 0 0 0.6em 0;
+}
+
+.right {
+  float: right;
+}
+
+.error {
+  color: #FF3333;
+  font-weight: bold;
+}
+
+.info {
+  color: #009900;
+  font-weight: bold;
+}
+
+.warning {
+  color: #999999;
+  font-weight: bold;
+}
+
+.note {
+  color: #666666;
+}
+
+.small {
+  height: 10px;
+}
+
+.variable {
+  font-family: "Calibri", "Trebuchet MS", sans-serif;
+}
+
+.vertical {
+  width: 1px;
+  border-left: 1px solid #000000;
+  height: 100%;
+}
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/users/add-pattern.xqm basex-8.2.3/basex-api/src/main/webapp/dba/users/add-pattern.xqm
--- basex-8.1.1/basex-api/src/main/webapp/dba/users/add-pattern.xqm	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/users/add-pattern.xqm	2015-07-14 10:54:40.000000000 +0000
@@ -24,7 +24,7 @@
  :)
 declare
   %rest:GET
-  %rest:path("dba/add-pattern")
+  %rest:path("/dba/add-pattern")
   %rest:query-param("name",    "{$name}")
   %rest:query-param("pattern", "{$pattern}")
   %rest:query-param("perm",    "{$perm}", "write")
@@ -83,7 +83,7 @@
 declare
   %updating
   %rest:POST
-  %rest:path("dba/add-pattern")
+  %rest:path("/dba/add-pattern")
   %rest:query-param("name",    "{$name}")
   %rest:query-param("perm",    "{$perm}")
   %rest:query-param("pattern", "{$pattern}")
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/users/create-user.xqm basex-8.2.3/basex-api/src/main/webapp/dba/users/create-user.xqm
--- basex-8.1.1/basex-api/src/main/webapp/dba/users/create-user.xqm	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/users/create-user.xqm	2015-07-14 10:54:40.000000000 +0000
@@ -22,7 +22,7 @@
  :)
 declare
   %rest:GET
-  %rest:path("dba/create-user")
+  %rest:path("/dba/create-user")
   %rest:query-param("name",  "{$name}")
   %rest:query-param("pw",    "{$pw}")
   %rest:query-param("perm",  "{$perm}", "none")
@@ -91,7 +91,7 @@
 declare
   %updating
   %rest:POST
-  %rest:path("dba/create-user")
+  %rest:path("/dba/create-user")
   %rest:query-param("name", "{$name}")
   %rest:query-param("pw",   "{$pw}")
   %rest:query-param("perm", "{$perm}")
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/users/drop-pattern.xqm basex-8.2.3/basex-api/src/main/webapp/dba/users/drop-pattern.xqm
--- basex-8.1.1/basex-api/src/main/webapp/dba/users/drop-pattern.xqm	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/users/drop-pattern.xqm	2015-07-14 10:54:40.000000000 +0000
@@ -19,7 +19,7 @@
 declare
   %updating
   %rest:GET
-  %rest:path("dba/drop-pattern")
+  %rest:path("/dba/drop-pattern")
   %rest:query-param("name",    "{$name}")
   %rest:query-param("pattern", "{$pattern}")
   %output:method("html")
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/users/drop-user.xqm basex-8.2.3/basex-api/src/main/webapp/dba/users/drop-user.xqm
--- basex-8.1.1/basex-api/src/main/webapp/dba/users/drop-user.xqm	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/users/drop-user.xqm	2015-07-14 10:54:40.000000000 +0000
@@ -18,7 +18,7 @@
 declare
   %updating
   %rest:GET
-  %rest:path("dba/drop-user")
+  %rest:path("/dba/drop-user")
   %rest:query-param("name", "{$names}")
   %output:method("html")
 function _:drop(
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/users/kill.xqm basex-8.2.3/basex-api/src/main/webapp/dba/users/kill.xqm
--- basex-8.1.1/basex-api/src/main/webapp/dba/users/kill.xqm	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/users/kill.xqm	2015-07-14 10:54:40.000000000 +0000
@@ -17,7 +17,7 @@
  :)
 declare
   %rest:GET
-  %rest:path("dba/kill-dba")
+  %rest:path("/dba/kill-dba")
   %rest:query-param("id", "{$ids}")
   %output:method("html")
 function _:drop(
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/users/users.xqm basex-8.2.3/basex-api/src/main/webapp/dba/users/users.xqm
--- basex-8.1.1/basex-api/src/main/webapp/dba/users/users.xqm	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/users/users.xqm	2015-07-14 10:54:40.000000000 +0000
@@ -24,7 +24,7 @@
  :)
 declare
   %rest:GET
-  %rest:path("dba/users")
+  %rest:path("/dba/users")
   %rest:query-param("sort", "{$sort}", "")
   %rest:query-param("error", "{$error}")
   %rest:query-param("info",  "{$info}")
@@ -114,7 +114,7 @@
  :)
 declare
   %rest:POST
-  %rest:path("dba/users")
+  %rest:path("/dba/users")
   %rest:query-param("action", "{$action}")
   %rest:query-param("name",   "{$names}")
   %rest:query-param("id",     "{$ids}")
diff -Nru basex-8.1.1/basex-api/src/main/webapp/dba/users/user.xqm basex-8.2.3/basex-api/src/main/webapp/dba/users/user.xqm
--- basex-8.1.1/basex-api/src/main/webapp/dba/users/user.xqm	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/dba/users/user.xqm	2015-07-14 10:54:40.000000000 +0000
@@ -27,7 +27,7 @@
  :)
 declare
   %rest:GET
-  %rest:path("dba/user")
+  %rest:path("/dba/user")
   %rest:query-param("name",     "{$name}")
   %rest:query-param("newname",  "{$newname}")
   %rest:query-param("pw",       "{$pw}")
@@ -149,7 +149,7 @@
  :)
 declare
   %rest:POST
-  %rest:path("dba/user")
+  %rest:path("/dba/user")
   %rest:form-param("action",  "{$action}")
   %rest:form-param("name",    "{$name}")
   %rest:form-param("pattern", "{$pattern}")
@@ -172,7 +172,7 @@
 declare
   %updating
   %rest:POST
-  %rest:path("dba/edit-user")
+  %rest:path("/dba/edit-user")
   %rest:query-param("name",    "{$name}")
   %rest:query-param("newname", "{$newname}")
   %rest:query-param("pw",      "{$pw}")
diff -Nru basex-8.1.1/basex-api/src/main/webapp/WEB-INF/web.xml basex-8.2.3/basex-api/src/main/webapp/WEB-INF/web.xml
--- basex-8.1.1/basex-api/src/main/webapp/WEB-INF/web.xml	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/main/webapp/WEB-INF/web.xml	2015-07-14 10:54:40.000000000 +0000
@@ -53,9 +53,10 @@
   </context-param>
   -->
 
-  <!-- Global session listener -->
+  <!-- Global session and servlet listener -->
   <listener>
     <listener-class>org.basex.http.SessionListener</listener-class>
+    <listener-class>org.basex.http.ServletListener</listener-class>
   </listener>
 
   <!-- RESTXQ Service (can be deactivated by removing this entry) -->
diff -Nru basex-8.1.1/basex-api/src/test/java/org/basex/AdvancedQueryTest.java basex-8.2.3/basex-api/src/test/java/org/basex/AdvancedQueryTest.java
--- basex-8.1.1/basex-api/src/test/java/org/basex/AdvancedQueryTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/test/java/org/basex/AdvancedQueryTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -22,7 +22,7 @@
     try(final QueryProcessor qp = new QueryProcessor(query, context)) {
       final ArrayOutput ao = new ArrayOutput();
       try(final Serializer ser = qp.getSerializer(ao)) {
-        qp.execute().serialize(ser);
+        qp.value().serialize(ser);
       }
       return ao.toString().replaceAll("(\\r|\\n)\\s*", "");
     } catch(final Exception ex) {
diff -Nru basex-8.1.1/basex-api/src/test/java/org/basex/api/xmldb/XMLDBBaseTest.java basex-8.2.3/basex-api/src/test/java/org/basex/api/xmldb/XMLDBBaseTest.java
--- basex-8.1.1/basex-api/src/test/java/org/basex/api/xmldb/XMLDBBaseTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/test/java/org/basex/api/xmldb/XMLDBBaseTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -21,7 +21,7 @@
   static final String DRIVER = BXDatabase.class.getName();
   /** Database/document path. */
   static final String URL =
-      "xmldb:" + Prop.PROJECT_NAME + "://" + S_LOCALHOST + ':' + StaticOptions.PORT.value + '/';
+      "xmldb:" + Prop.PROJECT_NAME + "://" + S_LOCALHOST + ':' + DB_PORT + '/';
   /** Name of the collection. */
   static final String COLL = "XMLDB";
   /** Database/document path. */
@@ -37,16 +37,13 @@
   /** Test document. */
   static final String DOC3 = "third.xml";
 
-  /** Context. */
-  private static final Context CONTEXT = new Context();
-
   /**
    * Create XMLDB database.
    * @throws BaseXException exception during database create
    */
   static void createDB() throws BaseXException {
-    new CreateDB(COLL, DOCPATH + DOC1).execute(CONTEXT);
-    new Close().execute(CONTEXT);
+    new CreateDB(COLL, DOCPATH + DOC1).execute(context);
+    new Close().execute(context);
   }
 
   /**
@@ -54,6 +51,6 @@
    * @throws BaseXException exception during database drop
    */
   static void dropDB() throws BaseXException {
-    new DropDB(COLL).execute(CONTEXT);
+    new DropDB(COLL).execute(context);
   }
 }
diff -Nru basex-8.1.1/basex-api/src/test/java/org/basex/http/FnHttpTest.java basex-8.2.3/basex-api/src/test/java/org/basex/http/FnHttpTest.java
--- basex-8.1.1/basex-api/src/test/java/org/basex/http/FnHttpTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/test/java/org/basex/http/FnHttpTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -14,19 +14,19 @@
 
 import org.basex.core.*;
 import org.basex.core.cmd.*;
-import org.basex.data.*;
 import org.basex.io.*;
 import org.basex.io.serial.*;
+import org.basex.query.QueryError.ErrType;
 import org.basex.query.*;
-import org.basex.query.QueryError.*;
 import org.basex.query.func.fn.*;
-import org.basex.query.iter.*;
+import org.basex.query.util.list.*;
+import org.basex.query.value.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.node.*;
 import org.basex.query.value.type.*;
 import org.basex.util.*;
 import org.basex.util.http.*;
-import org.basex.util.http.HttpRequest.*;
+import org.basex.util.http.HttpRequest.Part;
 import org.junit.*;
 import org.junit.Test;
 
@@ -72,7 +72,7 @@
         "<http:request method='put' status-only='true'>"
         + "<http:body media-type='text/xml'>" + BOOKS + "</http:body>"
         + "</http:request>", RESTURL), ctx)) {
-      checkResponse(qp.execute(), 1, HttpURLConnection.HTTP_CREATED);
+      checkResponse(qp.value(), 1, HttpURLConnection.HTTP_CREATED);
     }
   }
 
@@ -87,7 +87,7 @@
         "<http:request method='put' status-only='true'>"
         + "<http:body media-type='text/xml'>" + BOOKS + "</http:body>"
         + "</http:request>", RESTURL), ctx)) {
-      checkResponse(qp.execute(), 1, HttpURLConnection.HTTP_CREATED);
+      checkResponse(qp.value(), 1, HttpURLConnection.HTTP_CREATED);
     }
 
     // POST - query
@@ -99,7 +99,7 @@
         + "</query>"
         + "</http:body>"
         + "</http:request>", RESTURL), ctx)) {
-        checkResponse(qp.execute(), 2, HttpURLConnection.HTTP_OK);
+        checkResponse(qp.value(), 2, HttpURLConnection.HTTP_OK);
     }
 
     // Execute the same query but with content set from $bodies
@@ -111,7 +111,7 @@
         "<query xmlns='" + Prop.URL + "/rest'>"
         + "<text><![CDATA[<x>1</x>]]></text>"
         + "</query>"), ctx)) {
-      checkResponse(qp.execute(), 2, HttpURLConnection.HTTP_OK);
+      checkResponse(qp.value(), 2, HttpURLConnection.HTTP_OK);
     }
   }
 
@@ -124,25 +124,25 @@
     // GET1 - just send a GET request
     try(final QueryProcessor qp = new QueryProcessor(_HTTP_SEND_REQUEST.args(
         "<http:request method='get' href='" + REST_ROOT + "'/>"), ctx)) {
-      final Result r = qp.execute();
-      checkResponse(r, 2, HttpURLConnection.HTTP_OK);
+      final Value v = qp.value();
+      checkResponse(v, 2, HttpURLConnection.HTTP_OK);
 
-      assertEquals(NodeType.DOC, ((Iter) r).get(1).type);
+      assertEquals(NodeType.DOC, v.itemAt(1).type);
     }
 
     // GET2 - with override-media-type='text/plain'
     try(final QueryProcessor qp = new QueryProcessor(_HTTP_SEND_REQUEST.args(
         "<http:request method='get' override-media-type='text/plain'/>", REST_ROOT), ctx)) {
-      final Result r = qp.execute();
-      checkResponse(r, 2, HttpURLConnection.HTTP_OK);
+      final Value v = qp.value();
+      checkResponse(v, 2, HttpURLConnection.HTTP_OK);
 
-      assertEquals(AtomType.STR, ((Iter) r).get(1).type);
+      assertEquals(AtomType.STR, v.itemAt(1).type);
     }
 
     // Get3 - with status-only='true'
     try(final QueryProcessor qp = new QueryProcessor(_HTTP_SEND_REQUEST.args(
         "<http:request method='get' status-only='true'/>", REST_ROOT), ctx)) {
-      checkResponse(qp.execute(), 1, HttpURLConnection.HTTP_OK);
+      checkResponse(qp.value(), 1, HttpURLConnection.HTTP_OK);
     }
   }
 
@@ -157,13 +157,13 @@
         "<http:request method='put'>"
         + "<http:body media-type='text/xml'><ToBeDeleted/></http:body>"
         + "</http:request>", RESTURL), ctx)) {
-      qp.execute();
+      qp.value();
     }
 
     // DELETE
     try(final QueryProcessor qp = new QueryProcessor(_HTTP_SEND_REQUEST.args(
         "<http:request method='delete' status-only='true'/>", RESTURL), ctx)) {
-      checkResponse(qp.execute(), 1, HttpURLConnection.HTTP_OK);
+      checkResponse(qp.value(), 1, HttpURLConnection.HTTP_OK);
     }
   }
 
@@ -185,9 +185,9 @@
    */
   @Test
   public void sendReqNoParams() {
-    final Command c = new XQuery(_HTTP_SEND_REQUEST.args("()"));
+    final Command cmd = new XQuery(_HTTP_SEND_REQUEST.args("()"));
     try {
-      c.execute(ctx);
+      cmd.execute(ctx);
     } catch(final BaseXException ex) {
       assertTrue(ex.getMessage().contains(ErrType.HC.toString()));
     }
@@ -195,13 +195,13 @@
 
   /**
    * Tests an erroneous query.
-   * @throws QueryException query exception
+   * @throws Exception exception
    */
   @Test
-  public void error() throws QueryException {
+  public void error() throws Exception {
     try(final QueryProcessor qp = new QueryProcessor(_HTTP_SEND_REQUEST.args(
         "<http:request method='get'/>", RESTURL + "unknown") + "[1]/@status/data()", ctx)) {
-      assertEquals("404", qp.execute().toString());
+      assertEquals("404", qp.value().serialize().toString());
     }
   }
 
@@ -302,13 +302,13 @@
         + "</http:multipart>" + "</http:request>";
 
     final DBNode dbNode1 = new DBNode(new IOContent(multiReq));
-    final ValueBuilder bodies = new ValueBuilder();
+    final ItemList bodies = new ItemList();
     bodies.add(Str.get("Part1"));
     bodies.add(Str.get("Part2"));
     bodies.add(Str.get("Part3"));
 
     final HttpRequestParser rp = new HttpRequestParser(null);
-    final HttpRequest r = rp.parse(dbNode1.children().next(), bodies);
+    final HttpRequest r = rp.parse(dbNode1.children().next(), bodies.iter());
 
     assertEquals(2, r.attributes.size());
     assertEquals(2, r.headers.size());
@@ -344,14 +344,15 @@
         "<http:request xmlns:http='http://expath.org/ns/http-client' "
         + "method='GET' href='" + REST_ROOT + "' send-authorization='true' "
         + "auth-method='Basic' username='admin' password='admin'/>"), ctx)) {
-      checkResponse(qp.execute(), 2, HttpURLConnection.HTTP_OK);
+      checkResponse(qp.value(), 2, HttpURLConnection.HTTP_OK);
     }
     // wrong credentials
     try(final QueryProcessor qp = new QueryProcessor(_HTTP_SEND_REQUEST.args(
-        "<http:request xmlns:http='http://expath.org/ns/http-client' "
-        + "method='GET' href='" + REST_ROOT + "' send-authorization='true' "
-        + "auth-method='Basic' username='unknown' password='wrong'/>"), ctx)) {
-      checkResponse(qp.execute(), 1, HttpURLConnection.HTTP_UNAUTHORIZED);
+        "<http:request xmlns:http='http://expath.org/ns/http-client' " +
+        "method='GET' href='" + REST_ROOT + "' send-authorization='true' " +
+        "auth-method='Basic' username='unknown' password='wrong'/>") +
+        "[. instance of node()][@status = '401']", ctx)) {
+      checkResponse(qp.value(), 1, HttpURLConnection.HTTP_UNAUTHORIZED);
     }
   }
 
@@ -366,14 +367,15 @@
         "<http:request xmlns:http='http://expath.org/ns/http-client' method='GET' " +
         "send-authorization='true' auth-method='Digest' username='admin' password='admin' " +
         "href='" + REST_ROOT + "'/>"), ctx)) {
-      checkResponse(qp.execute(), 2, HttpURLConnection.HTTP_OK);
+      checkResponse(qp.value(), 2, HttpURLConnection.HTTP_OK);
     }
     // wrong credentials
     try(final QueryProcessor qp = new QueryProcessor(_HTTP_SEND_REQUEST.args(
         "<http:request xmlns:http='http://expath.org/ns/http-client' method='GET' " +
         "send-authorization='true' auth-method='Digest' username='unknown' password='wrong' " +
-        "href='" + REST_ROOT + "?query=()'/>"), ctx)) {
-      checkResponse(qp.execute(), 1, HttpURLConnection.HTTP_UNAUTHORIZED);
+        "href='" + REST_ROOT + "?query=()'/>") +
+        "[. instance of node()][@status = '401']", ctx)) {
+      checkResponse(qp.value(), 1, HttpURLConnection.HTTP_UNAUTHORIZED);
     }
   }
 
@@ -641,9 +643,9 @@
     // set content encoded in CP1251
     final String test = "\u0442\u0435\u0441\u0442";
     conn.content = Charset.forName("CP1251").encode(test).array();
-    final Iter i = new HttpResponse(null, ctx.options).getResponse(conn, true, null);
+    final ItemList res = new HttpResponse(null, ctx.options).getResponse(conn, true, null);
     // compare results
-    assertEquals(test, string(i.get(1).string(null)));
+    assertEquals(test, string(res.get(1).string(null)));
   }
 
   /**
@@ -683,10 +685,10 @@
         + ".... richtext..." + CRLF
         + "--boundary42" + CRLF + "Content-Type: text/x-whatever" + CRLF + CRLF
         + ".... fanciest formatted version  " + CRLF + "..."  + CRLF + "--boundary42--");
-    final ValueIter returned = new HttpResponse(null, ctx.options).getResponse(conn, true, null);
+    final ItemList returned = new HttpResponse(null, ctx.options).getResponse(conn, true, null);
 
     // Construct expected result
-    final ValueBuilder expected = new ValueBuilder();
+    final ItemList expected = new ItemList();
     final String response = "<http:response "
         + "xmlns:http='http://expath.org/ns/http-client' "
         + "status='200' message='OK'>"
@@ -761,10 +763,10 @@
         +  CRLF + "--simple boundary--" + CRLF
         + "This is the epilogue.  It is also to be ignored.");
     // Get response as sequence of XQuery items
-    final ValueIter returned = new HttpResponse(null, ctx.options).getResponse(conn, true, null);
+    final ItemList returned = new HttpResponse(null, ctx.options).getResponse(conn, true, null);
 
     // Construct expected result
-    final ValueBuilder expected = new ValueBuilder();
+    final ItemList expected = new ItemList();
     final String response = "<http:response "
         + "xmlns:http='http://expath.org/ns/http-client' "
         + "status='200' message='OK'>"
@@ -798,8 +800,7 @@
    * @param returned returned result
    * @throws Exception exception
    */
-  private static void compare(final ValueBuilder expected, final ValueIter returned)
-      throws Exception {
+  private static void compare(final ItemList expected, final ItemList returned) throws Exception {
 
     // Compare response with expected result
     assertEquals("Different number of results", expected.size(), returned.size());
@@ -841,19 +842,14 @@
 
   /**
    * Checks the response to an HTTP request.
-   * @param r query result
+   * @param v query result
    * @param itemsCount expected number of items
    * @param expStatus expected status
-   * @throws QueryException query exception
    */
-  private static void checkResponse(final Result r, final int itemsCount, final int expStatus)
-      throws QueryException {
-
-    assertTrue(r instanceof Iter);
-    final Iter res = (Iter) r;
-    assertEquals(itemsCount, r.size());
-    assertTrue(res.get(0) instanceof FElem);
-    final FElem response = (FElem) res.get(0);
+  private static void checkResponse(final Value v, final int itemsCount, final int expStatus) {
+    assertEquals(itemsCount, v.size());
+    assertTrue(v.itemAt(0) instanceof FElem);
+    final FElem response = (FElem) v.itemAt(0);
     assertNotNull(response.attributes());
     if(!eq(response.attribute(STATUS), token(expStatus))) {
       fail("Expected: " + expStatus + "\nFound: " + response);
diff -Nru basex-8.1.1/basex-api/src/test/java/org/basex/http/HTTPTest.java basex-8.2.3/basex-api/src/test/java/org/basex/http/HTTPTest.java
--- basex-8.1.1/basex-api/src/test/java/org/basex/http/HTTPTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/test/java/org/basex/http/HTTPTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -58,7 +58,7 @@
 
     final StringList sl = new StringList();
     if(local) sl.add("-l");
-    sl.add("-p" + DB_PORT, "-e" + EVENT_PORT, "-h" + HTTP_PORT, "-s" + STOP_PORT, "-z");
+    sl.add("-p" + DB_PORT, "-h" + HTTP_PORT, "-s" + STOP_PORT, "-z");
     sl.add("-U" + ADMIN, "-P" + ADMIN);
     System.setOut(NULL);
     try {
diff -Nru basex-8.1.1/basex-api/src/test/java/org/basex/http/rest/RESTGetTest.java basex-8.2.3/basex-api/src/test/java/org/basex/http/rest/RESTGetTest.java
--- basex-8.1.1/basex-api/src/test/java/org/basex/http/rest/RESTGetTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/test/java/org/basex/http/rest/RESTGetTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -116,9 +116,7 @@
    */
   @Test
   public void queryOption() throws IOException {
-    assertEquals("2",
-        get("?query=2,delete+node+<a/>&" + MainOptions.MIXUPDATES.name() + "=true")
-    );
+    assertEquals("2", get("?query=2,delete+node+<a/>&" + MainOptions.MIXUPDATES.name() + "=true"));
     try {
       get("?query=1,delete+node+<a/>&" + MainOptions.MIXUPDATES.name() + "=false");
       fail("Error expected.");
diff -Nru basex-8.1.1/basex-api/src/test/java/org/basex/SandboxTest.java basex-8.2.3/basex-api/src/test/java/org/basex/SandboxTest.java
--- basex-8.1.1/basex-api/src/test/java/org/basex/SandboxTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/test/java/org/basex/SandboxTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,19 +1,6 @@
 package org.basex;
 
-import static org.basex.core.Text.*;
-import static org.junit.Assert.*;
-
-import java.io.*;
-import java.util.concurrent.*;
-
-import org.basex.api.client.*;
 import org.basex.core.*;
-import org.basex.core.users.*;
-import org.basex.io.*;
-import org.basex.io.out.*;
-import org.basex.util.*;
-import org.basex.util.list.*;
-import org.basex.util.options.*;
 import org.junit.*;
 
 /**
@@ -22,166 +9,20 @@
  * @author BaseX Team 2005-15, BSD License
  * @author Christian Gruen
  */
-public abstract class SandboxTest {
-  /** Database port. */
-  protected static final int DB_PORT = 9996;
-  /** Event port. */
-  protected static final int EVENT_PORT = 9997;
-
-  /** Default output stream. */
-  public static final PrintStream OUT = System.out;
-  /** Default error stream. */
-  public static final PrintStream ERR = System.err;
-  /** Null output stream. */
-  public static final PrintStream NULL = new PrintStream(new NullOutput());
-  /** Test name. */
-  protected static final String NAME = Util.className(SandboxTest.class);
-  /** Database context. */
-  protected static Context context;
-
+public abstract class SandboxTest extends Sandbox {
   /**
    * Creates the sandbox.
    */
   @BeforeClass
-  public static void initSandbox() {
-    final IOFile sb = sandbox();
-    sb.delete();
-    assertTrue("Sandbox could not be created.", sb.md());
-    context = newContext();
+  public static void initTests() {
+    initSandbox();
   }
 
   /**
    * Removes test databases and closes the database context.
    */
   @AfterClass
-  public static void closeContext() {
-    context.close();
-    assertTrue("Sandbox could not be deleted.", sandbox().delete());
-  }
-
-  /**
-   * Creates a new specified context.
-   * @return context
-   */
-  public static Context newContext() {
-    final IOFile sb = sandbox();
-    Options.setSystem(StaticOptions.DBPATH.name(), sb.path() + "/data");
-    Options.setSystem(StaticOptions.WEBPATH.name(), sb.path() + "/webapp");
-    Options.setSystem(StaticOptions.RESTXQPATH.name(), sb.path() + "/webapp");
-    Options.setSystem(StaticOptions.REPOPATH.name(), sb.path() + "/repo");
-    try {
-      return new Context();
-    } finally {
-      Options.setSystem(StaticOptions.DBPATH.name(), "");
-      Options.setSystem(StaticOptions.WEBPATH.name(), "");
-      Options.setSystem(StaticOptions.RESTXQPATH.name(), "");
-      Options.setSystem(StaticOptions.REPOPATH.name(), "");
-    }
-  }
-
-  /**
-   * Creates a new, sandboxed server instance.
-   * @param args additional arguments
-   * @return server instance
-   * @throws IOException I/O exception
-   */
-  public static BaseXServer createServer(final String... args) throws IOException {
-    try {
-      System.setOut(NULL);
-      final StringList sl = new StringList("-z", "-p" + DB_PORT, "-e" + EVENT_PORT, "-q");
-      for(final String arg : args) sl.add(arg);
-      final BaseXServer server = new BaseXServer(sl.finish());
-      server.context.soptions.set(StaticOptions.DBPATH, sandbox().path());
-      return server;
-    } finally {
-      System.setOut(OUT);
-    }
-  }
-
-  /**
-   * Stops a server instance.
-   * @param server server
-   * @throws IOException I/O exception
-   */
-  public static void stopServer(final BaseXServer server) throws IOException {
-    try {
-      System.setOut(NULL);
-      if(server != null) server.stop();
-    } finally {
-      System.setOut(OUT);
-    }
-  }
-
-  /**
-   * Creates a client instance.
-   * @param login optional login data
-   * @return client instance
-   * @throws IOException I/O exception
-   */
-  public static ClientSession createClient(final String... login) throws IOException {
-    final String user = login.length > 0 ? login[0] : UserText.ADMIN;
-    final String pass = login.length > 1 ? login[1] : UserText.ADMIN;
-    return new ClientSession(S_LOCALHOST, DB_PORT, user, pass);
-  }
-
-  /**
-   * Returns the sandbox database path.
-   * @return database path
-   */
-  public static IOFile sandbox() {
-    return new IOFile(Prop.TMP, NAME);
-  }
-
-  /**
-   * Normalizes newlines in a query result.
-   * @param result input string
-   * @return normalized string
-   */
-  public static String normNL(final Object result) {
-    return result.toString().replaceAll("(\r?\n|\r) *", "\n");
-  }
-
-  /** Client. */
-  public static final class Client extends Thread {
-    /** Start signal. */
-    private final CountDownLatch startSignal;
-    /** Stop signal. */
-    private final CountDownLatch stopSignal;
-    /** Client session. */
-    private final ClientSession session;
-    /** Command string. */
-    private final Command cmd;
-    /** Fail flag. */
-    public String error;
-
-    /**
-     * Client constructor.
-     * @param c command string to execute
-     * @param start start signal
-     * @param stop stop signal
-     * @throws IOException I/O exception while establishing the session
-     */
-    public Client(final Command c, final CountDownLatch start, final CountDownLatch stop)
-        throws IOException {
-
-      session = createClient();
-      cmd = c;
-      startSignal = start;
-      stopSignal = stop;
-      start();
-    }
-
-    @Override
-    public void run() {
-      try {
-        if(startSignal != null) startSignal.await();
-        session.execute(cmd);
-        session.close();
-      } catch(final Throwable ex) {
-        error = "\n" + cmd + '\n' + ex;
-      } finally {
-        if(stopSignal != null) stopSignal.countDown();
-      }
-    }
+  public static void finishTests() {
+    finishSandbox();
   }
 }
diff -Nru basex-8.1.1/basex-api/src/test/java/org/expath/ns/GeoTest.java basex-8.2.3/basex-api/src/test/java/org/expath/ns/GeoTest.java
--- basex-8.1.1/basex-api/src/test/java/org/expath/ns/GeoTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-api/src/test/java/org/expath/ns/GeoTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -877,13 +877,18 @@
     final String q = "import module namespace geo='http://expath.org/ns/geo'; " +
         "declare namespace gml='http://www.opengis.net/gml';" + query;
 
+    System.setErr(NULL);
     try(final QueryProcessor qp = new QueryProcessor(q, context)) {
-      final String res = qp.execute().toString().replaceAll("(\\r|\\n) *", "");
+      final String res = qp.value().serialize().toString().replaceAll("(\\r|\\n) *", "");
       fail("Query did not fail:\n" + query + "\n[E] " +
           error + "...\n[F] " + res);
     } catch(final QueryException ex) {
       if(!ex.qname().eq(error))
         fail("Wrong error code:\n[E] " + error + "\n[F] " + ex.qname());
+    } catch(final Exception ex) {
+      fail(ex.toString());
+    } finally {
+      System.setErr(ERR);
     }
   }
 }
diff -Nru basex-8.1.1/basex-core/pom.xml basex-8.2.3/basex-core/pom.xml
--- basex-8.1.1/basex-core/pom.xml	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/pom.xml	2015-07-14 10:54:40.000000000 +0000
@@ -7,7 +7,7 @@
   <parent>
     <groupId>org.basex</groupId>
     <artifactId>basex-parent</artifactId>
-    <version>8.1.1</version>
+    <version>8.2.3</version>
     <relativePath>..</relativePath>
   </parent>
 
@@ -43,6 +43,11 @@
       <artifactId>jline</artifactId>
       <optional>true</optional>
     </dependency>
+    <dependency>
+      <groupId>com.thaiopensource</groupId>
+      <artifactId>jing</artifactId>
+      <optional>true</optional>
+    </dependency>
   </dependencies>
 
   <build>
diff -Nru basex-8.1.1/basex-core/.settings/checkstyle.xml basex-8.2.3/basex-core/.settings/checkstyle.xml
--- basex-8.1.1/basex-core/.settings/checkstyle.xml	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/.settings/checkstyle.xml	2015-07-14 10:54:40.000000000 +0000
@@ -1,12 +1,12 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE module PUBLIC "-//Puppy Crawl//DTD Check Configuration 1.3//EN" "http://www.puppycrawl.com/dtds/configuration_1_3.dtd">
 
-<!--
-    This configuration file was written by the eclipse-cs plugin configuration editor
+<!--
+    This configuration file was written by the eclipse-cs plugin configuration editor
 -->
-<!--
-    Checkstyle-Configuration: BaseX Checkstyle
-    Description: none
+<!--
+    Checkstyle-Configuration: BaseX Checkstyle
+    Description: none
 -->
 <module name="Checker">
   <property name="severity" value="warning"/>
@@ -26,7 +26,7 @@
     <module name="IllegalImport"/>
     <module name="RedundantImport"/>
     <module name="LineLength">
-      <property name="ignorePattern" value="^import"/>
+      <property name="ignorePattern" value="^(import| \*)"/>
       <property name="max" value="100"/>
       <property name="tabWidth" value="2"/>
     </module>
@@ -50,7 +50,6 @@
     </module>
     <module name="ModifierOrder"/>
     <module name="RedundantModifier"/>
-    <module name="AvoidNestedBlocks"/>
     <module name="EqualsHashCode">
       <property name="severity" value="ignore"/>
       <metadata name="net.sf.eclipsecs.core.lastEnabledSeverity" value="inherit"/>
diff -Nru basex-8.1.1/basex-core/.settings/dict basex-8.2.3/basex-core/.settings/dict
--- basex-8.1.1/basex-core/.settings/dict	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/.settings/dict	2015-07-14 10:54:40.000000000 +0000
@@ -277,9 +277,6 @@
 payload
 credentials
 xslt
-unwatches
-unwatching
-unwatch
 username
 aaron
 donovan
@@ -350,3 +347,7 @@
 inlineable
 autoflush
 soundex
+resizable
+updatable
+uris
+dist
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/api/client/ClientSession.java basex-8.2.3/basex-core/src/main/java/org/basex/api/client/ClientSession.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/api/client/ClientSession.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/api/client/ClientSession.java	2015-07-14 10:54:40.000000000 +0000
@@ -2,7 +2,6 @@
 
 import java.io.*;
 import java.net.*;
-import java.util.*;
 
 import org.basex.core.*;
 import org.basex.core.parse.Commands.Cmd;
@@ -30,9 +29,6 @@
  * @author Christian Gruen
  */
 public class ClientSession extends Session {
-  /** Event notifications. */
-  private final Map<String, EventNotifier> notifiers =
-      Collections.synchronizedMap(new HashMap<String, EventNotifier>());
   /** Server output (buffered). */
   final PrintOutput sout;
   /** Server input. */
@@ -40,10 +36,6 @@
 
   /** Socket reference. */
   private final Socket socket;
-  /** Socket event host. */
-  private final String ehost;
-  /** Socket event reference. */
-  private Socket esocket;
 
   /**
    * Constructor, specifying login data.
@@ -100,7 +92,6 @@
       final String password, final OutputStream output) throws IOException {
 
     super(output);
-    ehost = host;
     socket = new Socket();
     try {
       // limit timeout to five seconds
@@ -161,7 +152,6 @@
 
   @Override
   public synchronized void close() throws IOException {
-    if(esocket != null) esocket.close();
     socket.close();
   }
 
@@ -178,70 +168,6 @@
   }
 
   /**
-   * Watches an event.
-   * @param name event name
-   * @param notifier event notification
-   * @throws IOException I/O exception
-   */
-  public void watch(final String name, final EventNotifier notifier) throws IOException {
-    sout.write(ServerCmd.WATCH.code);
-    if(esocket == null) {
-      sout.flush();
-      final BufferInput bi = new BufferInput(sin);
-      final int eport = Integer.parseInt(bi.readString());
-      // initialize event socket
-      esocket = new Socket();
-      esocket.connect(new InetSocketAddress(ehost, eport), 5000);
-      final OutputStream so = esocket.getOutputStream();
-      so.write(bi.readBytes());
-      so.write(0);
-      so.flush();
-      final InputStream is = esocket.getInputStream();
-      is.read();
-      listen(is);
-    }
-    send(name);
-    sout.flush();
-    receive(null);
-    notifiers.put(name, notifier);
-  }
-
-  /**
-   * Unwatches an event.
-   * @param name event name
-   * @throws IOException I/O exception
-   */
-  public void unwatch(final String name) throws IOException {
-    sout.write(ServerCmd.UNWATCH.code);
-    send(name);
-    sout.flush();
-    receive(null);
-    notifiers.remove(name);
-  }
-
-  /**
-   * Starts the listener thread.
-   * @param input input stream
-   */
-  private void listen(final InputStream input) {
-    final BufferInput bi = new BufferInput(input);
-    new Thread() {
-      @Override
-      public void run() {
-        try {
-          while(true) {
-            final EventNotifier n = notifiers.get(bi.readString());
-            final String l = bi.readString();
-            if(n != null) n.notify(l);
-          }
-        } catch(final IOException ex) {
-          // listener did not receive any more input
-        }
-      }
-    }.start();
-  }
-
-  /**
    * Sends the specified stream to the server.
    * @param input input stream
    * @throws IOException I/O exception
@@ -334,9 +260,4 @@
     if(!ok(bi)) throw new BaseXException(bi.readString());
     return o.toString();
   }
-
-  @Override
-  public String toString() {
-     return ehost + ':' + socket.getPort();
-  }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/api/dom/BXElem.java basex-8.2.3/basex-core/src/main/java/org/basex/api/dom/BXElem.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/api/dom/BXElem.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/api/dom/BXElem.java	2015-07-14 10:54:40.000000000 +0000
@@ -148,9 +148,9 @@
    * @return node or {@code null}
    */
   private ANode attribute(final String name) {
-    final AxisIter ai = nd.attributes();
+    final BasicNodeIter iter = nd.attributes();
     final byte[] nm = Token.token(name);
-    for(ANode n; (n = ai.next()) != null;) if(Token.eq(nm, n.name())) return n.finish();
+    for(ANode n; (n = iter.next()) != null;) if(Token.eq(nm, n.name())) return n.finish();
     return null;
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/api/dom/BXNode.java basex-8.2.3/basex-core/src/main/java/org/basex/api/dom/BXNode.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/api/dom/BXNode.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/api/dom/BXNode.java	2015-07-14 10:54:40.000000000 +0000
@@ -268,9 +268,9 @@
    */
   final BXNList getElements(final String name) {
     final ANodeList nb = new ANodeList();
-    final AxisIter ai = nd.descendant();
+    final BasicNodeIter iter = nd.descendant();
     final byte[] nm = "*".equals(name) ? null : token(name);
-    for(ANode n; (n = ai.next()) != null;) {
+    for(ANode n; (n = iter.next()) != null;) {
       if(n.type == NodeType.ELM && (nm == null || eq(nm, n.name()))) nb.add(n.finish());
     }
     return new BXNList(nb);
@@ -281,7 +281,7 @@
    * @param iter axis iterator
    * @return node cache
    */
-  static ANodeList finish(final AxisIter iter) {
+  static ANodeList finish(final BasicNodeIter iter) {
     final ANodeList nl = new ANodeList();
     for(ANode n; (n = iter.next()) != null;) nl.add(n.finish());
     return nl;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/BaseXClient.java basex-8.2.3/basex-core/src/main/java/org/basex/BaseXClient.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/BaseXClient.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/BaseXClient.java	2015-07-14 10:54:40.000000000 +0000
@@ -3,6 +3,7 @@
 import static org.basex.core.Text.*;
 
 import java.io.*;
+import java.net.*;
 
 import org.basex.api.client.*;
 import org.basex.core.*;
@@ -57,6 +58,13 @@
       Util.out(PASSWORD + COLS);
       pass = Util.password();
     }
-    return new ClientSession(context, user, pass, out);
+
+    final String host = context.soptions.get(StaticOptions.HOST);
+    final int port = context.soptions.get(StaticOptions.PORT);
+    try {
+      return new ClientSession(host, port, user, pass, out);
+    } catch(final ConnectException ex) {
+      throw new BaseXException(CONNECTION_ERROR_X, port);
+    }
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/BaseXGUI.java basex-8.2.3/basex-core/src/main/java/org/basex/BaseXGUI.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/BaseXGUI.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/BaseXGUI.java	2015-07-14 10:54:40.000000000 +0000
@@ -63,10 +63,6 @@
 
     // read options
     final GUIOptions gopts = new GUIOptions();
-    // cache results to pass them on to all visualizations
-    context.options.set(MainOptions.CACHEQUERY, true);
-    // reduce number of results to save memory
-    context.options.set(MainOptions.MAXHITS, gopts.get(GUIOptions.MAXHITS));
 
     // initialize look and feel
     init(gopts);
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/BaseX.java basex-8.2.3/basex-core/src/main/java/org/basex/BaseX.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/BaseX.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/BaseX.java	2015-07-14 10:54:40.000000000 +0000
@@ -86,9 +86,6 @@
           execute(val);
           execute(new Set(MainOptions.QUERYPATH, ""), false);
           console = false;
-        } else if(c == 'd') {
-          // toggle debug mode
-          Prop.debug ^= true;
         } else if(c == 'D') {
           // hidden option: show/hide dot query graph
           execute(new Set(MainOptions.DOTPLAN, null), false);
@@ -232,8 +229,11 @@
       String v = null;
       if(arg.dash()) {
         c = arg.next();
-        if(c == 'b' || c == 'c' || c == 'C' || c == 'i' || c == 'I' || c == 'o' || c == 'q' ||
-            c == 'r' || c == 's' || c == 't' && local()) {
+        if(c == 'd') {
+          // activate debug mode
+          Prop.debug = true;
+        } else if(c == 'b' || c == 'c' || c == 'C' || c == 'i' || c == 'I' || c == 'o' ||
+            c == 'q' || c == 'r' || c == 's' || c == 't' && local()) {
           // options followed by a string
           v = arg.string();
         } else if(c == 'd' || c == 'D' && local() || c == 'u' && local() || c == 'R' ||
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/BaseXServer.java basex-8.2.3/basex-core/src/main/java/org/basex/BaseXServer.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/BaseXServer.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/BaseXServer.java	2015-07-14 10:54:40.000000000 +0000
@@ -9,7 +9,6 @@
 import org.basex.api.client.*;
 import org.basex.core.*;
 import org.basex.io.*;
-import org.basex.io.in.*;
 import org.basex.server.*;
 import org.basex.server.Log.LogType;
 import org.basex.util.*;
@@ -30,10 +29,6 @@
   private volatile boolean running;
   /** Indicates if server is to be stopped. */
   private volatile boolean stop;
-  /** Event server socket. */
-  private ServerSocket esocket;
-  /** Events listener. */
-  private EventListener events;
   /** Initial commands. */
   private StringList commands;
   /** Server socket. */
@@ -79,9 +74,6 @@
 
     final StaticOptions sopts = context.soptions;
     final int port = sopts.get(StaticOptions.SERVERPORT);
-    final int eport = sopts.get(StaticOptions.EVENTPORT);
-    // ensure that port numbers are different
-    if(port == eport) throw new BaseXException(PORT_TWICE_X, port);
 
     final String host = sopts.get(StaticOptions.SERVERHOST);
     final InetAddress addr = host.isEmpty() ? null : InetAddress.getByName(host);
@@ -94,7 +86,7 @@
     }
 
     if(stop) {
-      stop(port, eport);
+      stop(port);
       if(!quiet) Util.outln(SRV_STOPPED_PORT_X, port);
       Performance.sleep(1000);
       return;
@@ -107,13 +99,10 @@
       socket = new ServerSocket();
       socket.setReuseAddress(true);
       socket.bind(new InetSocketAddress(addr, port));
-      esocket = new ServerSocket();
-      esocket.setReuseAddress(true);
-      esocket.bind(new InetSocketAddress(addr, eport));
       stopFile = stopFile(port);
     } catch(final IOException ex) {
       context.log.writeServer(LogType.ERROR, Util.message(ex));
-      throw ex;
+      throw ex instanceof BindException ? new IOException(Util.info(SRV_RUNNING_X, port)) : ex;
     }
 
     new Thread(this).start();
@@ -204,7 +193,6 @@
 
     try {
       // close interactive input if server was stopped by another process
-      esocket.close();
       socket.close();
     } catch(final IOException ex) {
       Util.errln(ex);
@@ -230,9 +218,6 @@
           case 'D': // hidden flag: daemon mode
             daemon = true;
             break;
-          case 'e': // parse event port
-            context.soptions.set(StaticOptions.EVENTPORT, arg.number());
-            break;
           case 'n': // parse host the server is bound to
             context.soptions.set(StaticOptions.SERVERHOST, arg.string());
             break;
@@ -266,8 +251,7 @@
    * @throws IOException I/O exception
    */
   public void stop() throws IOException {
-    final StaticOptions sopts = context.soptions;
-    stop(sopts.get(StaticOptions.SERVERPORT), sopts.get(StaticOptions.EVENTPORT));
+    stop(context.soptions.get(StaticOptions.SERVERPORT));
   }
 
   // STATIC METHODS ===========================================================
@@ -280,16 +264,17 @@
    */
   public static void start(final int port, final String... args) throws BaseXException {
     // check if server is already running (needs some time)
-    if(ping(S_LOCALHOST, port)) throw new BaseXException(SRV_RUNNING);
+    final String host = S_LOCALHOST;
+    if(ping(host, port)) throw new BaseXException(SRV_RUNNING_X, port);
 
     Util.start(BaseXServer.class, args);
 
     // try to connect to the new server instance
     for(int c = 1; c < 10; ++c) {
       Performance.sleep(c * 100L);
-      if(ping(S_LOCALHOST, port)) return;
+      if(ping(host, port)) return;
     }
-    throw new BaseXException(CONNECTION_ERROR);
+    throw new BaseXException(CONNECTION_ERROR_X, port);
   }
 
   /**
@@ -314,20 +299,19 @@
   /**
    * Stops the server.
    * @param port server port
-   * @param eport event port
    * @throws IOException I/O exception
    */
-  public static void stop(final int port, final int eport) throws IOException {
+  public static void stop(final int port) throws IOException {
     final IOFile stop = stopFile(port);
     try {
       stop.touch();
-      new Socket(S_LOCALHOST, eport).close();
       new Socket(S_LOCALHOST, port).close();
       // wait and check if server was really stopped
       do Performance.sleep(100); while(ping(S_LOCALHOST, port));
-    } catch(final IOException ex) {
+    } catch(final ConnectException ex) {
+      throw new IOException(Util.info(CONNECTION_ERROR_X, port));
+    } finally {
       stop.delete();
-      throw ex;
     }
   }
 
@@ -342,47 +326,6 @@
     }
   }
 
-  /**
-   * Initializes the event listener.
-   */
-  public void initEvents() {
-    if(events == null) {
-      events = new EventListener();
-      events.start();
-    }
-  }
-
-  /**
-   * Inner class to listen for event registrations.
-   *
-   * @author BaseX Team 2005-15, BSD License
-   * @author Andreas Weiler
-   */
-  private final class EventListener extends Thread {
-    @Override
-    public void run() {
-      while(running) {
-        try {
-          final Socket es = esocket.accept();
-          if(stopFile.exists()) {
-            esocket.close();
-            break;
-          }
-          final BufferInput bi = new BufferInput(es.getInputStream());
-          final long id = Strings.toLong(bi.readString());
-          for(final ClientListener s : context.sessions) {
-            if(s.getId() == id) {
-              s.register(es);
-              break;
-            }
-          }
-        } catch(final IOException ex) {
-          break;
-        }
-      }
-    }
-  }
-
   @Override
   public String header() {
     return Util.info(S_CONSOLE, S_SERVER);
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/build/Builder.java basex-8.2.3/basex-core/src/main/java/org/basex/build/Builder.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/build/Builder.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/build/Builder.java	2015-07-14 10:54:40.000000000 +0000
@@ -8,7 +8,6 @@
 
 import org.basex.core.*;
 import org.basex.data.*;
-import org.basex.data.atomic.*;
 import org.basex.index.name.*;
 import org.basex.index.path.*;
 import org.basex.io.*;
@@ -28,7 +27,7 @@
   /** Tree structure. */
   final PathSummary path = new PathSummary();
   /** Namespace index. */
-  final Namespaces ns = new Namespaces();
+  final Namespaces nspaces = new Namespaces();
   /** Parser instance. */
   final Parser parser;
   /** Database name. */
@@ -47,9 +46,9 @@
   Names attrNames;
 
   /** Parent stack. */
-  private final IntList pstack = new IntList();
+  private final IntList parStack = new IntList();
   /** Stack with element names. */
-  private final IntList tstack = new IntList();
+  private final IntList elemStack = new IntList();
   /** Current tree height. */
   private int level;
 
@@ -82,9 +81,9 @@
    */
   public final void openDoc(final byte[] value) throws IOException {
     path.put(0, Data.DOC, level);
-    pstack.set(level++, meta.size);
+    parStack.set(level++, meta.size);
     addDoc(value);
-    ns.prepare();
+    nspaces.open();
   }
 
   /**
@@ -92,10 +91,10 @@
    * @throws IOException I/O exception
    */
   public final void closeDoc() throws IOException {
-    final int pre = pstack.get(--level);
+    final int pre = parStack.get(--level);
     setSize(pre, meta.size - pre);
     ++meta.ndocs;
-    ns.close(meta.size);
+    nspaces.close(meta.size);
   }
 
   /**
@@ -120,8 +119,8 @@
   public final void emptyElem(final byte[] name, final Atts att, final Atts nsp)
       throws IOException {
     addElem(name, att, nsp);
-    final int pre = pstack.get(level);
-    ns.close(pre);
+    final int pre = parStack.get(level);
+    nspaces.close(pre);
     if(att.size() > IO.MAXATTS) setSize(pre, meta.size - pre);
   }
 
@@ -132,9 +131,9 @@
   public final void closeElem() throws IOException {
     checkStop();
     --level;
-    final int pre = pstack.get(level);
+    final int pre = parStack.get(level);
     setSize(pre, meta.size - pre);
-    ns.close(pre);
+    nspaces.close(pre);
   }
 
   /**
@@ -223,24 +222,24 @@
    * size value; if this node has further descendants, {@link #setSize} must
    * be called to set the final size value.
    * @param dist distance to parent
-   * @param name element name
+   * @param nameId id of element name
    * @param asize number of attributes
-   * @param uri namespace uri reference
-   * @param ne namespace flag
+   * @param uriId id of namespace uri
+   * @param ne namespace flag (indicates if this element introduces new namespaces)
    * @throws IOException I/O exception
    */
-  protected abstract void addElem(int dist, int name, int asize, int uri, boolean ne)
+  protected abstract void addElem(int dist, int nameId, int asize, int uriId, boolean ne)
       throws IOException;
 
   /**
    * Adds an attribute to the database.
-   * @param name attribute name
+   * @param nameId id of attribute name
    * @param value attribute value
    * @param dist distance to parent
-   * @param uri namespace uri reference
+   * @param uriId id of namespace uri
    * @throws IOException I/O exception
    */
-  protected abstract void addAttr(int name, byte[] value, int dist, int uri) throws IOException;
+  protected abstract void addAttr(int nameId, byte[] value, int dist, int uriId) throws IOException;
 
   /**
    * Adds a text node to the database.
@@ -264,55 +263,53 @@
   /**
    * Adds an element node to the storage.
    * @param name element name
-   * @param att attributes
+   * @param atts attributes
    * @param nsp namespaces
    * @throws IOException I/O exception
    */
-  private void addElem(final byte[] name, final Atts att, final Atts nsp) throws IOException {
+  private void addElem(final byte[] name, final Atts atts, final Atts nsp) throws IOException {
     // get reference of element name
-    int n = elemNames.index(name, null, true);
-    path.put(n, Data.ELEM, level);
+    int nameId = elemNames.index(name, null, true);
+    path.put(nameId, Data.ELEM, level);
 
     // cache pre value
     final int pre = meta.size;
     // remember id of element name and parent reference
-    tstack.set(level, n);
-    pstack.set(level, pre);
+    elemStack.set(level, nameId);
+    parStack.set(level, pre);
 
     // parse namespaces
-    ns.prepare();
-    final int nl = nsp.size();
-    for(int nx = 0; nx < nl; nx++) ns.add(nsp.name(nx), nsp.value(nx), pre);
+    nspaces.open(pre, nsp);
 
     // get and store element references
-    final int dis = level == 0 ? 1 : pre - pstack.get(level - 1);
-    final int as = att.size();
-    int u = ns.uri(name, true);
-    if(u == 0 && indexOf(name, ':') != -1 && !eq(prefix(name), XML))
+    final int dis = level == 0 ? 1 : pre - parStack.get(level - 1);
+    final int as = atts.size();
+    final byte[] pref = prefix(name);
+    int uriId = nspaces.uriIdForPrefix(pref, true);
+    if(uriId == 0 && pref.length != 0 && !eq(pref, XML))
       throw new BuildException(WHICHNS, parser.detail(), prefix(name));
-    addElem(dis, n, Math.min(IO.MAXATTS, as + 1), u, nl != 0);
+    addElem(dis, nameId, Math.min(IO.MAXATTS, as + 1), uriId, !nsp.isEmpty());
 
     // get and store attribute references
     for(int a = 0; a < as; ++a) {
-      final byte[] av = att.value(a);
-      final byte[] an = att.name(a);
-      n = attrNames.index(an, av, true);
-      u = ns.uri(an, false);
-      if(u == 0 && indexOf(an, ':') != -1 && !eq(prefix(an), XML))
+      final byte[] an = atts.name(a), av = atts.value(a);
+      final byte[] ap = prefix(an);
+      nameId = attrNames.index(an, av, true);
+      uriId = nspaces.uriIdForPrefix(ap, false);
+      if(uriId == 0 && ap.length != 0 && !eq(ap, XML))
         throw new BuildException(WHICHNS, parser.detail(), an);
 
-      path.put(n, Data.ATTR, level + 1, av, meta);
-      addAttr(n, av, Math.min(IO.MAXATTS, a + 1), u);
+      path.put(nameId, Data.ATTR, level + 1, av, meta);
+      addAttr(nameId, av, Math.min(IO.MAXATTS, a + 1), uriId);
     }
 
     // set leaf node information in index
-    if(level > 1) elemNames.stat(tstack.get(level - 1)).setLeaf(false);
+    if(level > 1) elemNames.stat(elemStack.get(level - 1)).setLeaf(false);
 
-    // check if data ranges exceed database limits,
-    // based on the storage details in {@link Data}
+    // check if data ranges exceed database limits, based on the storage details in {@link Data}
     limit(elemNames.size(), 0x8000, LIMITELEMS);
     limit(attrNames.size(), 0x8000, LIMITATTS);
-    limit(ns.size(), 0x100, LIMITNS);
+    limit(nspaces.size(), 0x100, LIMITNS);
     if(meta.size < 0) limit(0, 0, LIMITRANGE);
   }
 
@@ -336,7 +333,7 @@
   private void addText(final byte[] value, final byte kind) throws IOException {
     final int l = level;
     if(l > 1) {
-      final int i = tstack.get(l - 1);
+      final int i = elemStack.get(l - 1);
       // text node processing for statistics
       if(kind == Data.TEXT) elemNames.index(i, value);
       // set leaf node information in index
@@ -344,6 +341,6 @@
     }
 
     path.put(0, kind, l, value, meta);
-    addText(value, l == 0 ? 1 : meta.size - pstack.get(l - 1), kind);
+    addText(value, l == 0 ? 1 : meta.size - parStack.get(l - 1), kind);
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/build/DiskBuilder.java basex-8.2.3/basex-core/src/main/java/org/basex/build/DiskBuilder.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/build/DiskBuilder.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/build/DiskBuilder.java	2015-07-14 10:54:40.000000000 +0000
@@ -8,7 +8,6 @@
 import org.basex.core.*;
 import org.basex.core.cmd.*;
 import org.basex.data.*;
-import org.basex.data.atomic.*;
 import org.basex.index.name.*;
 import org.basex.io.*;
 import org.basex.io.in.DataInput;
@@ -101,7 +100,7 @@
     meta.dbfile(DATATMP).delete();
 
     // return database instance
-    return new DiskData(meta, elemNames, attrNames, path, ns);
+    return new DiskData(meta, elemNames, attrNames, path, nspaces);
   }
 
   @Override
@@ -144,12 +143,12 @@
   }
 
   @Override
-  protected void addElem(final int dist, final int name, final int asize, final int uri,
+  protected void addElem(final int dist, final int nameId, final int asize, final int uriId,
       final boolean ne) throws IOException {
 
     tout.write1(asize << 3 | Data.ELEM);
-    tout.write2((ne ? 1 << 15 : 0) | name);
-    tout.write1(uri);
+    tout.write2((ne ? 1 << 15 : 0) | nameId);
+    tout.write1(uriId);
     tout.write4(dist);
     tout.write4(asize);
     tout.write4(meta.size++);
@@ -158,13 +157,13 @@
   }
 
   @Override
-  protected void addAttr(final int name, final byte[] value, final int dist, final int uri)
+  protected void addAttr(final int nameId, final byte[] value, final int dist, final int uriId)
       throws IOException {
 
     tout.write1(dist << 3 | Data.ATTR);
-    tout.write2(name);
+    tout.write2(nameId);
     tout.write5(textOff(value, false));
-    tout.write4(uri);
+    tout.write4(uriId);
     tout.write4(meta.size++);
   }
 
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/build/json/JsonOptions.java basex-8.2.3/basex-core/src/main/java/org/basex/build/json/JsonOptions.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/build/json/JsonOptions.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/build/json/JsonOptions.java	2015-07-14 10:54:40.000000000 +0000
@@ -11,13 +11,13 @@
  * @author Christian Gruen
  */
 public class JsonOptions extends Options {
-  /** Option: merge type information. */
+  /** Option: merge type information (custom). */
   public static final BooleanOption MERGE = new BooleanOption("merge", false);
-  /** Option: include string types. */
+  /** Option: include string types (custom). */
   public static final BooleanOption STRINGS = new BooleanOption("strings", false);
-  /** Option: lax conversion of names to QNames. */
+  /** Option: lax conversion of names to QNames (custom). */
   public static final BooleanOption LAX = new BooleanOption("lax", false);
-  /** Option: format. */
+  /** Option: format (custom). */
   public static final EnumOption<JsonFormat> FORMAT = new EnumOption<>("format", JsonFormat.DIRECT);
 
   /** JSON formats. */
@@ -25,6 +25,7 @@
     /** Direct.        */ DIRECT,
     /** Attributes.    */ ATTRIBUTES,
     /** JsonML.        */ JSONML,
+    /** Basic.         */ BASIC,
     /** Map (non-XML). */ MAP;
 
     @Override
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/build/json/JsonParserOptions.java basex-8.2.3/basex-core/src/main/java/org/basex/build/json/JsonParserOptions.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/build/json/JsonParserOptions.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/build/json/JsonParserOptions.java	2015-07-14 10:54:40.000000000 +0000
@@ -11,23 +11,26 @@
  * @author Christian Gruen
  */
 public final class JsonParserOptions extends JsonOptions {
-  /** Option: encoding. */
-  public static final StringOption ENCODING = new StringOption("encoding");
-  /** Option: unescape special characters. */
+  /** Option: unescape special characters (parse-json, json-to-xml). */
   public static final BooleanOption UNESCAPE = new BooleanOption("unescape", true);
-  /** Option: liberal parsing. */
+  /** Option: liberal parsing (parse-json, json-to-xml). */
   public static final BooleanOption LIBERAL = new BooleanOption("liberal", false);
-  /** Option: fallback function. */
+  /** Option: fallback function (parse-json, json-to-xml). */
   public static final FuncOption FALLBACK = new FuncOption("fallback");
-  /** Option: handle duplicates. */
+  /** Option: handle duplicates (parse-json, json-to-xml). */
   public static final EnumOption<JsonDuplicates> DUPLICATES =
-      new EnumOption<>("duplicates", JsonDuplicates.USE_LAST);
+      new EnumOption<>("duplicates", JsonDuplicates.class);
+  /** Option: validation (json-to-xml). */
+  public static final BooleanOption VALIDATE = new BooleanOption("validate", false);
+  /** Option: encoding (custom). */
+  public static final StringOption ENCODING = new StringOption("encoding");
 
   /** Duplicate handling. */
   public enum JsonDuplicates {
     /** Reject.    */ REJECT,
     /** Use first. */ USE_FIRST,
-    /** Use last.  */ USE_LAST;
+    /** Use last.  */ USE_LAST,
+    /** Retain.    */ RETAIN;
 
     @Override
     public String toString() {
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/build/json/JsonSerialOptions.java basex-8.2.3/basex-core/src/main/java/org/basex/build/json/JsonSerialOptions.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/build/json/JsonSerialOptions.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/build/json/JsonSerialOptions.java	2015-07-14 10:54:40.000000000 +0000
@@ -9,6 +9,8 @@
  * @author Christian Gruen
  */
 public final class JsonSerialOptions extends JsonOptions {
-  /** Option: escape special characters. */
+  /** Option: merge type information (xml-to-json, custom). */
+  public static final BooleanOption INDENT = new BooleanOption("indent", false);
+  /** Option: escape special characters (custom). */
   public static final BooleanOption ESCAPE = new BooleanOption("escape", true);
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/build/MemBuilder.java basex-8.2.3/basex-core/src/main/java/org/basex/build/MemBuilder.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/build/MemBuilder.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/build/MemBuilder.java	2015-07-14 10:54:40.000000000 +0000
@@ -3,7 +3,6 @@
 import java.io.*;
 
 import org.basex.data.*;
-import org.basex.data.atomic.*;
 import org.basex.io.*;
 
 /**
@@ -82,7 +81,7 @@
    * Initializes the builder.
    */
   public void init() {
-    data = new MemData(path, ns, parser.options);
+    data = new MemData(path, nspaces, parser.options);
 
     meta = data.meta;
     meta.name = dbname;
@@ -116,15 +115,15 @@
   }
 
   @Override
-  protected void addElem(final int dist, final int name, final int asize, final int uri,
+  protected void addElem(final int dist, final int nameId, final int asize, final int uriId,
       final boolean ne) {
-    data.elem(dist, name, asize, asize, uri, ne);
+    data.elem(dist, nameId, asize, asize, uriId, ne);
     data.insert(meta.size);
   }
 
   @Override
-  protected void addAttr(final int name, final byte[] value, final int dist, final int uri) {
-    data.attr(meta.size, dist, name, value, uri, false);
+  protected void addAttr(final int nameId, final byte[] value, final int dist, final int uriId) {
+    data.attr(meta.size, dist, nameId, value, uriId);
     data.insert(meta.size);
   }
 
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/Add.java basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/Add.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/Add.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/Add.java	2015-07-14 10:54:40.000000000 +0000
@@ -9,8 +9,8 @@
 import org.basex.core.parse.*;
 import org.basex.core.users.*;
 import org.basex.data.*;
-import org.basex.data.atomic.*;
 import org.basex.io.*;
+import org.basex.query.up.atomic.*;
 import org.basex.util.*;
 
 /**
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/AEvent.java basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/AEvent.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/AEvent.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/AEvent.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,26 +0,0 @@
-package org.basex.core.cmd;
-
-import org.basex.core.*;
-import org.basex.core.locks.*;
-import org.basex.core.users.*;
-
-/**
- * Abstract class for database events.
- *
- * @author BaseX Team 2005-15, BSD License
- * @author Christian Gruen
- */
-abstract class AEvent extends Command {
-  /**
-   * Protected constructor.
-   * @param args arguments
-   */
-  AEvent(final String... args) {
-    super(Perm.ADMIN, false, args);
-  }
-
-  @Override
-  public void databases(final LockResult lr) {
-    lr.write.add(DBLocking.EVENT); // Event operations are exclusive
-  }
-}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/AQuery.java basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/AQuery.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/AQuery.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/AQuery.java	2015-07-14 10:54:40.000000000 +0000
@@ -10,13 +10,13 @@
 import org.basex.core.locks.*;
 import org.basex.core.parse.*;
 import org.basex.core.users.*;
-import org.basex.data.*;
 import org.basex.io.*;
 import org.basex.io.out.*;
 import org.basex.io.serial.*;
 import org.basex.io.serial.dot.*;
 import org.basex.query.*;
 import org.basex.query.iter.*;
+import org.basex.query.value.*;
 import org.basex.query.value.item.*;
 import org.basex.util.*;
 
@@ -37,7 +37,7 @@
   private QueryInfo info;
 
   /** Query result. */
-  private Result result;
+  private Value result;
 
   /**
    * Protected constructor.
@@ -57,8 +57,8 @@
   final boolean query(final String query) {
     final Performance p = new Performance();
     String error;
-    if(cause != null) {
-      error = Util.message(cause);
+    if(exception != null) {
+      error = Util.message(exception);
     } else {
       try {
         long hits = 0;
@@ -79,8 +79,8 @@
 
           final PrintOutput po = r == 0 && serial ? out : new NullOutput();
           try(final Serializer ser = qp.getSerializer(po)) {
-            if(options.get(MainOptions.CACHEQUERY)) {
-              result = qp.execute();
+            if(maxResults >= 0) {
+              result = qp.cache(maxResults);
               info.evaluating += p.time();
               result.serialize(ser);
               hits = result.size();
@@ -108,7 +108,7 @@
         return info(info.toString(qp, out.size(), hits, options.get(MainOptions.QUERYINFO)));
 
       } catch(final QueryException | IOException ex) {
-        cause = ex;
+        exception = ex;
         error = Util.message(ex);
       } catch(final ProcException ex) {
         error = INTERRUPTED;
@@ -157,38 +157,19 @@
       return qp.updating;
     } catch(final QueryException ex) {
       Util.debug(ex);
-      cause = ex;
+      exception = ex;
       qp.close();
       return false;
     }
   }
 
   /**
-   * Evaluates the query and returns the result as {@link DBNodes} instance.
-   * @return result or {@code null} if result cannot be represented as {@link DBNodes} instance.
-   */
-  final DBNodes dbNodes() {
-    try {
-      final Result res = qp(args[0], context).execute();
-      if(res instanceof DBNodes) return (DBNodes) res;
-      // return empty result set
-      if(res.size() == 0) return new DBNodes(context.data());
-    } catch(final QueryException ex) {
-      error(Util.message(ex));
-    } finally {
-      qp.close();
-      qp = null;
-    }
-    return null;
-  }
-
-  /**
    * Returns a query processor instance.
    * @param query query string
    * @param ctx database context
    * @return query processor
    */
-  private QueryProcessor qp(final String query, final Context ctx) {
+  protected QueryProcessor qp(final String query, final Context ctx) {
     if(qp == null) {
       qp = proc(new QueryProcessor(query, ctx));
       if(info == null) info = qp.qc.info;
@@ -197,6 +178,16 @@
   }
 
   /**
+   * Closes the query processor.
+   */
+  protected void closeQp() {
+    if(qp != null) {
+      qp.close();
+      qp = null;
+    }
+  }
+
+  /**
    * Returns the serialization parameters.
    * @param ctx context
    * @return serialization parameters
@@ -322,8 +313,8 @@
   }
 
   @Override
-  public final Result finish() {
-    final Result r = result;
+  public final Value finish() {
+    final Value r = result;
     result = null;
     return r;
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/AUser.java basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/AUser.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/AUser.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/AUser.java	2015-07-14 10:54:40.000000000 +0000
@@ -38,10 +38,10 @@
    */
   boolean run(final int off, final boolean opt) {
     final String name = args[off];
-    final String pattern = off + 1 < args.length ? args[off + 1] : null;
+    final String pattern = off + 1 < args.length ? args[off + 1] : "";
 
     if(!Databases.validName(name, true)) return error(NAME_INVALID_X, name);
-    if(pattern != null && !Databases.validName(pattern, true))
+    if(!pattern.isEmpty() && !Databases.validName(pattern, true))
       return error(NAME_INVALID_X, pattern);
 
     // retrieve all users; stop if no user is found
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/CreateEvent.java basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/CreateEvent.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/CreateEvent.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/CreateEvent.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,35 +0,0 @@
-package org.basex.core.cmd;
-
-import static org.basex.core.Text.*;
-
-import org.basex.core.parse.*;
-import org.basex.core.parse.Commands.Cmd;
-import org.basex.core.parse.Commands.CmdCreate;
-
-/**
- * Evaluates the 'create event' command and creates a new event.
- *
- * @author BaseX Team 2005-15, BSD License
- * @author Roman Raedle
- * @author Andreas Weiler
- */
-public final class CreateEvent extends AEvent {
-  /**
-   * Default constructor.
-   * @param name user name
-   */
-  public CreateEvent(final String name) {
-    super(name);
-  }
-
-  @Override
-  protected boolean run() {
-    final String name = args[0];
-    return context.events.create(name) ? info(EVENT_CREATED_X, name) : error(EVENT_EXISTS_X, name);
-  }
-
-  @Override
-  public void build(final CmdBuilder cb) {
-    cb.init(Cmd.CREATE + " " + CmdCreate.EVENT).args();
-  }
-}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/Delete.java basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/Delete.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/Delete.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/Delete.java	2015-07-14 10:54:40.000000000 +0000
@@ -4,8 +4,8 @@
 
 import org.basex.core.users.*;
 import org.basex.data.*;
-import org.basex.data.atomic.*;
 import org.basex.io.*;
+import org.basex.query.up.atomic.*;
 import org.basex.util.list.*;
 
 /**
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/DropEvent.java basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/DropEvent.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/DropEvent.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/DropEvent.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,36 +0,0 @@
-package org.basex.core.cmd;
-
-import static org.basex.core.Text.*;
-
-import org.basex.core.parse.*;
-import org.basex.core.parse.Commands.Cmd;
-import org.basex.core.parse.Commands.CmdDrop;
-
-/**
- * Evaluates the 'drop event' command and drops an existing event.
- *
- * @author BaseX Team 2005-15, BSD License
- * @author Roman Raedle
- * @author Andreas Weiler
- */
-public final class DropEvent extends AEvent {
-  /**
-   * Default constructor.
-   * @param name user name
-   */
-  public DropEvent(final String name) {
-    super(name);
-  }
-
-  @Override
-  protected boolean run() {
-    final String name = args[0];
-    return context.events.drop(name) ?
-        info(EVENT_DROPPED_X, name) : error(EVENT_UNKNOWN_X, name);
-  }
-
-  @Override
-  public void build(final CmdBuilder cb) {
-    cb.init(Cmd.DROP + " " + CmdDrop.EVENT).args();
-  }
-}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/DropUser.java basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/DropUser.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/DropUser.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/DropUser.java	2015-07-14 10:54:40.000000000 +0000
@@ -26,10 +26,10 @@
   /**
    * Constructor for dropping local database users.
    * @param name name of user
-   * @param db database (may be {@code null})
+   * @param pattern database pattern (may be {@code null})
    */
-  public DropUser(final String name, final String db) {
-    super(name, db);
+  public DropUser(final String name, final String pattern) {
+    super(name, pattern == null ? "" : pattern);
   }
 
   @Override
@@ -46,13 +46,13 @@
     final Users users = context.users;
     final User user = users.get(name);
     if(user != null) {
-      if(pattern == null) {
+      if(pattern.isEmpty()) {
         for(final ClientListener s : context.sessions) {
           if(s.context().user().name().equals(name)) return !info(USER_LOGGED_IN_X, name);
         }
       }
       users.drop(users.get(name), pattern);
-      return info(pattern == null ? USER_DROPPED_X : USER_DROPPED_X_X, name, pattern);
+      return info(pattern.isEmpty() ? USER_DROPPED_X : USER_DROPPED_X_X, name, pattern);
     }
     return true;
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/Execute.java basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/Execute.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/Execute.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/Execute.java	2015-07-14 10:54:40.000000000 +0000
@@ -54,7 +54,7 @@
         proc(null);
         sb.append(c.info());
         if(!ok) {
-          cause = c.cause;
+          exception = c.exception();
           return error(sb.toString());
         }
       }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/Get.java basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/Get.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/Get.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/Get.java	2015-07-14 10:54:40.000000000 +0000
@@ -33,15 +33,15 @@
 
   /**
    * Default constructor.
-   * @param key key to be found
+   * @param key key to be found (can be {@code null})
    */
   public Get(final String key) {
-    super(key);
+    super(key == null ? "" : key);
   }
 
   @Override
   protected boolean run() throws IOException {
-    if(args[0] == null) {
+    if(args[0].isEmpty()) {
       // retrieve values of all options
       if(context.user().has(Perm.ADMIN)) {
         out.println(GLOBAL_OPTIONS + COL);
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/Grant.java basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/Grant.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/Grant.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/Grant.java	2015-07-14 10:54:40.000000000 +0000
@@ -29,25 +29,26 @@
    * Constructor, specifying a database.
    * @param permission permission
    * @param user user name
-   * @param pattern database pattern
+   * @param pattern database pattern (may be {@code null})
    */
   public Grant(final Object permission, final String user, final String pattern) {
-    super(permission.toString(), user, pattern);
+    super(permission.toString(), user, pattern == null ? "" : pattern);
   }
 
   @Override
   protected boolean run() {
     // find permission
     final CmdPerm cmd = getOption(CmdPerm.class);
+    final boolean local = args[2].isEmpty();
     if(cmd == CmdPerm.NONE) {
       prm = Perm.NONE;
     } else if(cmd == CmdPerm.READ) {
       prm = Perm.READ;
     } else if(cmd == CmdPerm.WRITE) {
       prm = Perm.WRITE;
-    } else if(cmd == CmdPerm.CREATE && args[2] == null) {
+    } else if(cmd == CmdPerm.CREATE && local) {
       prm = Perm.CREATE;
-    } else if(cmd == CmdPerm.ADMIN && args[2] == null) {
+    } else if(cmd == CmdPerm.ADMIN && local) {
       prm = Perm.ADMIN;
     }
     if(prm == null) return error(PERM_UNKNOWN_X, args[0]);
@@ -63,7 +64,7 @@
     final Users users = context.users;
     final User user = users.get(name);
     Users.perm(user, prm, pattern);
-    return info(pattern == null ? GRANTED_X_X : GRANTED_ON_X_X_X, args[0], name, pattern);
+    return info(pattern.isEmpty() ? GRANTED_X_X : GRANTED_ON_X_X_X, args[0], name, pattern);
   }
 
   @Override
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/Help.java basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/Help.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/Help.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/Help.java	2015-07-14 10:54:40.000000000 +0000
@@ -18,16 +18,16 @@
 public final class Help extends Command {
   /**
    * Default constructor.
-   * @param arg optional argument
+   * @param arg argument (can be {@code null})
    */
   public Help(final String arg) {
-    super(Perm.NONE, arg);
+    super(Perm.NONE, arg == null ? "" : arg);
   }
 
   @Override
   protected boolean run() throws IOException {
     final String key = args[0];
-    if(key != null && !key.isEmpty()) {
+    if(!key.isEmpty()) {
       final Cmd cmd = getOption(key, Cmd.class);
       if(cmd == null) return error(UNKNOWN_CMD_X, this);
       out.println(cmd.help(true));
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/InfoDB.java basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/InfoDB.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/InfoDB.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/InfoDB.java	2015-07-14 10:54:40.000000000 +0000
@@ -63,13 +63,13 @@
     // count number of raw files
     info(tb, DOCUMENTS, meta.ndocs);
     info(tb, BINARIES, meta.path != null ? meta.binaries().descendants().size() : 0);
-    info(tb, TIMESTAMP, DateTime.format(new Date(meta.dbtime()), DateTime.DATETIME));
+    info(tb, TIMESTAMP, DateTime.format(new Date(meta.dbtime())));
     if(meta.corrupt) tb.add(' ' + DB_CORRUPT + NL);
 
     tb.add(NL).addExt(header, RES_PROPS);
     if(create && !meta.original.isEmpty()) info(tb, INPUT_PATH, meta.original);
     if(meta.filesize != 0) info(tb, INPUT_SIZE, Performance.format(meta.filesize));
-    info(tb, TIMESTAMP, DateTime.format(new Date(meta.time), DateTime.DATETIME));
+    info(tb, TIMESTAMP, DateTime.format(new Date(meta.time)));
     info(tb, ENCODING, meta.encoding);
     info(tb, MainOptions.CHOP.name(), meta.chop);
 
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/InfoIndex.java basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/InfoIndex.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/InfoIndex.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/InfoIndex.java	2015-07-14 10:54:40.000000000 +0000
@@ -34,13 +34,13 @@
    * @param type optional index type, defined in {@link CmdIndexInfo}
    */
   public InfoIndex(final Object type) {
-    super(true, type != null && type != CmdIndexInfo.NULL ? type.toString() : null);
+    super(true, type != null && type != CmdIndexInfo.NULL ? type.toString() : "");
   }
 
   @Override
   protected boolean run() throws IOException {
     final Data data = context.data();
-    if(args[0] != null) {
+    if(!args[0].isEmpty()) {
       final CmdIndexInfo ci = getOption(CmdIndexInfo.class);
       if(ci == null) return error(UNKNOWN_CMD_X, this);
       final byte[] inf = info(ci, data, options);
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/Info.java basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/Info.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/Info.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/Info.java	2015-07-14 10:54:40.000000000 +0000
@@ -46,10 +46,8 @@
     info(tb, VERSINFO, Prop.VERSION);
 
     final User user = context.user();
-    if(user.has(Perm.CREATE)) {
-      Performance.gc(1);
-      info(tb, USED_MEM, Performance.getMemory());
-    }
+    info(tb, USED_MEM, Performance.getMemory());
+
     if(user.has(Perm.ADMIN)) {
       final StaticOptions sopts = context.soptions;
       tb.add(NL + GLOBAL_OPTIONS + COL + NL);
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/InfoStorage.java basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/InfoStorage.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/InfoStorage.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/InfoStorage.java	2015-07-14 10:54:40.000000000 +0000
@@ -12,6 +12,9 @@
 import org.basex.core.parse.Commands.CmdInfo;
 import org.basex.core.users.*;
 import org.basex.data.*;
+import org.basex.query.*;
+import org.basex.query.value.*;
+import org.basex.query.value.seq.*;
 import org.basex.util.*;
 import org.basex.util.list.*;
 
@@ -25,11 +28,11 @@
 public final class InfoStorage extends AQuery {
   /**
    * Default constructor.
-   * @param arg optional arguments
+   * @param arg arguments (can be {@code null})
    */
   public InfoStorage(final String... arg) {
-    super(Perm.READ, true, arg.length > 0 && arg[0] != null && !arg[0].isEmpty() ?
-      arg[0] : null, arg.length >  1 ? arg[1] : null);
+    super(Perm.READ, true, arg.length > 0 && arg[0] != null ? arg[0] : "",
+                           arg.length > 1 && arg[1] != null ? arg[1] : "");
   }
 
   @Override
@@ -38,19 +41,30 @@
     final String start = args[0];
     final String end = args[1];
 
-    // evaluate input as number range or xquery
-    final DBNodes nodes = start != null && toInt(start) == Integer.MIN_VALUE ? dbNodes() : null;
+    DBNodes nodes = null;
+    if(!start.isEmpty() && toInt(start) == Integer.MIN_VALUE) {
+      try {
+        // evaluate input as query
+        final Value value = qp(args[0], context).value();
+        if(value instanceof DBNodes) nodes = (DBNodes) value;
+      } catch(final QueryException ex) {
+        error(Util.message(ex));
+      } finally {
+        closeQp();
+      }
+    }
+
     final Data data = context.data();
     if(nodes != null) {
       final Table table = th();
-      for(final int n : nodes.pres) table(table, data, n);
+      for(final int pre : nodes.pres()) table(table, data, pre);
       out.print(table.finish());
     } else {
       int ps = 0;
       int pe = 1000;
 
-      if(start != null) {
-        if(end != null) {
+      if(!start.isEmpty()) {
+        if(!end.isEmpty()) {
           ps = toInt(start);
           pe = toInt(end) + 1;
         } else {
@@ -120,9 +134,9 @@
     tl.add(data.size(pre, k));
     tl.add(data.attSize(pre, k));
     tl.add(data.id(pre));
-    final int u = data.uri(pre, k);
-    if(data.nsFlag(pre)) tl.add("+" + u);
-    else tl.add(u);
+    final int uriId = data.uriId(pre, k);
+    if(data.nsFlag(pre)) tl.add("+" + uriId);
+    else tl.add(uriId);
     tl.add(TABLEKINDS[k]);
 
     final byte[] cont;
@@ -141,7 +155,7 @@
   @Override
   public void build(final CmdBuilder cb) {
     cb.init(Cmd.INFO + " " + CmdInfo.STORAGE);
-    if(args[0] != null && toInt(args[0]) == Integer.MIN_VALUE) {
+    if(!args[0].isEmpty() && toInt(args[0]) == Integer.MIN_VALUE) {
       cb.xquery(0);
     } else {
       cb.arg(0).arg(1);
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/List.java basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/List.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/List.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/List.java	2015-07-14 10:54:40.000000000 +0000
@@ -32,7 +32,7 @@
 
   /**
    * Default constructor.
-   * @param name database name
+   * @param name database name (can be {@code null})
    */
   public List(final String name) {
     this(name, null);
@@ -40,21 +40,21 @@
 
   /**
    * Default constructor.
-   * @param name database name
-   * @param path database path
+   * @param name database name (can be {@code null})
+   * @param path database path (can be {@code null})
    */
   public List(final String name, final String path) {
-    super(Perm.NONE, name, path);
+    super(Perm.NONE, name == null ? "" : name, path == null ? "" : path);
   }
 
   @Override
   protected boolean run() throws IOException {
-    return args[0] == null || args[0].isEmpty() ? list() : listDB();
+    return args[0].isEmpty() ? list() : listDB();
   }
 
   @Override
   public void databases(final LockResult lr) {
-    if(args[0] == null || args[0].isEmpty()) lr.readAll = true;
+    if(args[0].isEmpty()) lr.readAll = true;
     else lr.read.add(args[0]);
   }
 
@@ -75,26 +75,25 @@
 
     for(final String name : context.filter(Perm.READ, context.databases.listDBs())) {
       String file = null;
-      long size = 0;
-      int docs = 0;
+      long dbsize = 0;
+      int count = 0;
 
-      final MetaData meta = new MetaData(name, options, soptions);
       try {
+        final MetaData meta = new MetaData(name, options, soptions);
         meta.read();
-        size = meta.dbsize();
-        docs = meta.ndocs;
+        dbsize = meta.dbsize();
         file = meta.original;
+        // add number of raw files
+        count = meta.ndocs + new IOFile(soptions.dbpath(name), IO.RAW).descendants().size();
       } catch(final IOException ex) {
         file = ERROR;
       }
-      // count number of raw files
-      final int bin = new IOFile(soptions.dbpath(name), IO.RAW).descendants().size();
 
       // create entry
       final TokenList tl = new TokenList(create ? 4 : 3);
       tl.add(name);
-      tl.add(docs + bin);
-      tl.add(size);
+      tl.add(count);
+      tl.add(dbsize);
       if(create) tl.add(file);
       table.contents.add(tl);
     }
@@ -108,8 +107,7 @@
    * @throws IOException I/O exception
    */
   private boolean listDB() throws IOException {
-    final String db = args[0];
-    final String path = args[1] != null ? args[1] : "";
+    final String db = args[0], path = args[1];
     if(!Databases.validName(db)) return error(NAME_INVALID_X, db);
 
     final Table table = new Table();
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/Open.java basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/Open.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/Open.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/Open.java	2015-07-14 10:54:40.000000000 +0000
@@ -8,6 +8,7 @@
 import org.basex.core.locks.*;
 import org.basex.core.users.*;
 import org.basex.data.*;
+import org.basex.query.value.seq.*;
 import org.basex.util.*;
 
 /**
@@ -28,10 +29,10 @@
   /**
    * Default constructor.
    * @param name name of database
-   * @param path database path
+   * @param path database path (can be {@code null})
    */
   public Open(final String name, final String path) {
-    super(Perm.NONE, name, path);
+    super(Perm.NONE, name, path == null ? "" : path);
   }
 
   @Override
@@ -48,7 +49,7 @@
         context.openDB(data);
 
         final String path = args[1];
-        if(path != null && !path.isEmpty()) {
+        if(!path.isEmpty()) {
           context.current(new DBNodes(data, data.resources.docs(path).toArray()));
         }
         if(data.meta.oldindex()) info(H_INDEX_FORMAT);
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/OptimizeAll.java basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/OptimizeAll.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/OptimizeAll.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/OptimizeAll.java	2015-07-14 10:54:40.000000000 +0000
@@ -14,6 +14,7 @@
 import org.basex.index.*;
 import org.basex.io.*;
 import org.basex.io.serial.*;
+import org.basex.query.value.item.*;
 import org.basex.query.value.node.*;
 import org.basex.util.*;
 import org.basex.util.list.*;
@@ -184,7 +185,7 @@
     public void parse(final Builder build) throws IOException {
       final Serializer ser = new BuilderSerializer(build) {
         @Override
-        protected void startOpen(final byte[] name) throws IOException {
+        protected void startOpen(final QNm name) throws IOException {
           super.startOpen(name);
           if(cmd != null) cmd.pre++;
         }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/Optimize.java basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/Optimize.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/Optimize.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/Optimize.java	2015-07-14 10:54:40.000000000 +0000
@@ -116,13 +116,13 @@
           elms.push(0);
           ++n;
         } else if(kind == Data.ELEM) {
-          final int id = data.name(pre);
+          final int id = data.nameId(pre);
           data.elemNames.index(data.elemNames.key(id), null, true);
           data.paths.put(id, Data.ELEM, level);
           pars.push(pre);
           elms.push(id);
         } else if(kind == Data.ATTR) {
-          final int id = data.name(pre);
+          final int id = data.nameId(pre);
           final byte[] val = data.text(pre, false);
           data.attrNames.index(data.attrNames.key(id), val, true);
           data.paths.put(id, Data.ATTR, level, val, md);
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/Rename.java basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/Rename.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/Rename.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/Rename.java	2015-07-14 10:54:40.000000000 +0000
@@ -80,10 +80,10 @@
     final String path = string(data.text(pre, true));
     if(Prop.CASE ? path.equals(src) : path.equalsIgnoreCase(src)) return trg;
 
-    // source references a directory: merge target path and file name
-    final String name = src.isEmpty() ? path : path.substring(src.length() + 1);
-    if(trg.isEmpty()) return name;
-    if(trg.endsWith("/")) return trg + name;
-    return trg + '/' + name;
+    // directory references: add trailing slashes to non-empty paths
+    final String source = src.isEmpty() || src.endsWith("/") ? src : src + '/';
+    final String target = trg.isEmpty() || trg.endsWith("/") ? trg : trg + '/';
+    // merge target with old path
+    return target + path.substring(source.length());
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/Replace.java basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/Replace.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/Replace.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/Replace.java	2015-07-14 10:54:40.000000000 +0000
@@ -6,8 +6,8 @@
 
 import org.basex.core.users.*;
 import org.basex.data.*;
-import org.basex.data.atomic.*;
 import org.basex.io.*;
+import org.basex.query.up.atomic.*;
 import org.basex.util.list.*;
 
 /**
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/ShowEvents.java basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/ShowEvents.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/ShowEvents.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/ShowEvents.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,33 +0,0 @@
-package org.basex.core.cmd;
-
-import java.io.*;
-
-import org.basex.core.locks.*;
-import org.basex.core.parse.*;
-import org.basex.core.parse.Commands.Cmd;
-import org.basex.core.parse.Commands.CmdShow;
-
-/**
- * Evaluates the 'show events' command and lists all existing events.
- *
- * @author BaseX Team 2005-15, BSD License
- * @author Roman Raedle
- * @author Andreas Weiler
- */
-public final class ShowEvents extends AEvent {
-  @Override
-  protected boolean run() throws IOException {
-    out.println(context.events.info());
-    return true;
-  }
-
-  @Override
-  public void build(final CmdBuilder cb) {
-    cb.init(Cmd.SHOW + " " + CmdShow.EVENTS).args();
-  }
-
-  @Override
-  public void databases(final LockResult lr) {
-    lr.read.add(DBLocking.EVENT);
-  }
-}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/ShowUsers.java basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/ShowUsers.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/ShowUsers.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/ShowUsers.java	2015-07-14 10:54:40.000000000 +0000
@@ -27,17 +27,17 @@
 
   /**
    * Constructor, specifying a database.
-   * @param db database (for showing users)
+   * @param db database (can be {@code null})
    */
   public ShowUsers(final String db) {
-    super(Perm.ADMIN, db);
+    super(Perm.ADMIN, db == null ? "" : db);
   }
 
   @Override
   protected boolean run() throws IOException {
-    final String name = args[0] == null || args[0].isEmpty() ? null : args[0];
-    if(name != null && !Databases.validName(name)) return error(NAME_INVALID_X, name);
-    out.println(context.users.info(name).finish());
+    final String name = args[0];
+    if(!name.isEmpty() && !Databases.validName(name)) return error(NAME_INVALID_X, name);
+    out.println(context.users.info(name.isEmpty() ? null : name).finish());
     return true;
   }
 
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/Test.java basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/Test.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/core/cmd/Test.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/core/cmd/Test.java	2015-07-14 10:54:40.000000000 +0000
@@ -47,7 +47,7 @@
       sb.append(suite.skipped).append(' ').append("skipped.");
       return suite.errors + suite.failures == 0 ? info(sb.toString()) : error(sb.toString());
     } catch(final IOException ex) {
-      cause = ex;
+      exception = ex;
       return error(Util.message(ex));
     }
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/core/Command.java basex-8.2.3/basex-core/src/main/java/org/basex/core/Command.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/core/Command.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/core/Command.java	2015-07-14 10:54:40.000000000 +0000
@@ -10,6 +10,7 @@
 import org.basex.core.users.*;
 import org.basex.data.*;
 import org.basex.io.out.*;
+import org.basex.query.value.*;
 import org.basex.util.*;
 import org.basex.util.list.*;
 import org.xml.sax.*;
@@ -29,21 +30,25 @@
   public final Perm perm;
   /** Indicates if the command requires an opened database. */
   public final boolean openDB;
-  /** Exception, resulting from command execution. */
-  public Exception cause;
 
-  /** Performance measurements. */
-  protected Performance perf;
   /** Database context. */
   protected Context context;
+  /** Convenience access to database options. */
+  protected MainOptions options;
+  /** Convenience access to static options. */
+  protected StaticOptions soptions;
+
   /** Output stream. */
   protected PrintOutput out;
   /** Optional input source. */
   protected InputSource in;
-  /** Database options. */
-  protected MainOptions options;
-  /** Static options. */
-  protected StaticOptions soptions;
+
+  /** Exception, resulting from command execution. */
+  protected Exception exception;
+  /** Performance measurements. */
+  protected Performance perf;
+  /** Maximum number of results (ignored if negative). */
+  protected int maxResults = -1;
 
   /** Container for query information. */
   private final TokenBuilder info = new TokenBuilder();
@@ -94,7 +99,7 @@
       // run command and return success flag
       if(!run(ctx, os)) {
         final BaseXException ex = new BaseXException(info());
-        ex.initCause(cause);
+        ex.initCause(exception);
         throw ex;
       }
     } catch(final RuntimeException th) {
@@ -154,11 +159,18 @@
   }
 
   /**
-   * Returns a cached result set generated by {@link AQuery#query}. Will only yield results if
-   * {@link MainOptions#CACHEQUERY} is set, and can only be called once.
+   * Returns the cause of an error.
+   * @return error
+   */
+  public final Exception exception() {
+    return exception;
+  }
+
+  /**
+   * Returns a cached result set generated by {@link AQuery#query}. Can only be called once.
    * @return result set
    */
-  public Result finish() {
+  public Value finish() {
     return null;
   }
 
@@ -183,8 +195,7 @@
 
   /**
    * Closes an open data reference and returns {@code true} if this command will change the
-   * {@link Context#data()} reference. This method is required by the progress dialog in the
-   * frontend.
+   * {@link Context#data()} reference. This method is required by the GUI progress dialog.
    * @param ctx database context
    * @return result of check
    */
@@ -194,8 +205,16 @@
   }
 
   /**
-   * Returns true if this command returns a progress value. This method is required by the progress
-   * dialog in the frontend.
+   * Enforces a maximum number of query results. This method is required by the GUI.
+   * @param max maximum number of results (ignored if negative)
+   */
+  public final void maxResults(final int max) {
+    maxResults = max;
+  }
+
+  /**
+   * Returns true if this command returns a progress value.
+   * This method is required by the GUI progress dialog.
    * @return result of check
    */
   public boolean supportsProg() {
@@ -203,8 +222,8 @@
   }
 
   /**
-   * Returns true if this command can be stopped. This method is required by the progress dialog in
-   * the frontend.
+   * Returns true if this command can be stopped.
+   * This method is required by the GUI progress dialog.
    * @return result of check
    */
   public boolean stoppable() {
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/core/Context.java basex-8.2.3/basex-core/src/main/java/org/basex/core/Context.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/core/Context.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/core/Context.java	2015-07-14 10:54:40.000000000 +0000
@@ -5,6 +5,7 @@
 import org.basex.data.*;
 import org.basex.io.random.*;
 import org.basex.query.util.pkg.*;
+import org.basex.query.value.seq.*;
 import org.basex.server.*;
 import org.basex.util.*;
 import org.basex.util.list.*;
@@ -28,8 +29,6 @@
   public final StaticOptions soptions;
   /** Client sessions. */
   public final Sessions sessions;
-  /** Event pool. */
-  public final Events events;
   /** Opened databases. */
   public final Datas datas;
   /** Users. */
@@ -85,7 +84,6 @@
   public Context(final Context ctx) {
     soptions = ctx.soptions;
     datas = ctx.datas;
-    events = ctx.events;
     sessions = ctx.sessions;
     databases = ctx.databases;
     blocker = ctx.blocker;
@@ -113,7 +111,6 @@
   private Context(final StaticOptions soptions) {
     this.soptions = soptions;
     datas = new Datas();
-    events = new Events();
     sessions = new Sessions();
     blocker = new ClientBlocker();
     databases = new Databases(soptions);
@@ -176,9 +173,7 @@
   public DBNodes current() {
     if(data == null) return null;
     if(current != null) return current;
-    final DBNodes nodes = new DBNodes(data, data.resources.docs().toArray());
-    nodes.all = true;
-    return nodes;
+    return new DBNodes(data, true, data.resources.docs().toArray());
   }
 
   /**
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/core/Databases.java basex-8.2.3/basex-core/src/main/java/org/basex/core/Databases.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/core/Databases.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/core/Databases.java	2015-07-14 10:54:40.000000000 +0000
@@ -14,6 +14,9 @@
  * @author Jens Erat
  */
 public final class Databases {
+  /** Date pattern. */
+  public static final String DATE = "\\d{4}-\\d{2}-\\d{2}-\\d{2}-\\d{2}-\\d{2}";
+
   /** Allowed characters for database names (additional to letters and digits).
    * The following characters are invalid:
    * <ul>
@@ -27,8 +30,7 @@
   /** Regex representation of allowed database characters. */
   private static final String REGEXCHARS = DBCHARS.replaceAll("(.)", "\\\\$1");
   /** Pattern to extract the database name from a backup file name. */
-  private static final Pattern ZIPPATTERN =
-      Pattern.compile(DateTime.PATTERN + '\\' + IO.ZIPSUFFIX + '$');
+  private static final Pattern ZIPPATTERN = Pattern.compile('-' + DATE + '\\' + IO.ZIPSUFFIX + '$');
   /** Regex indicator. */
   private static final Pattern REGEX = Pattern.compile(".*[*?,].*");
 
@@ -145,7 +147,7 @@
     if(file.exists()) {
       backups.add(db);
     } else {
-      final Pattern regex = regex(db, DateTime.PATTERN + '\\' + IO.ZIPSUFFIX);
+      final Pattern regex = regex(db, '-' + DATE + '\\' + IO.ZIPSUFFIX);
       for(final IOFile f : soptions.dbpath().children()) {
         final String n = f.name();
         if(regex.matcher(n).matches()) backups.add(n.substring(0, n.lastIndexOf('.')));
@@ -162,7 +164,16 @@
    * @return name of the database ({@code [dbname]})
    */
   public static String name(final String backup) {
-    return Pattern.compile(DateTime.PATTERN + '$').split(backup)[0];
+    return Pattern.compile('-' + DATE + '$').split(backup)[0];
+  }
+
+  /**
+   * Extracts the date of a database from the name of a backup.
+   * @param backup name of the backup file, including the date
+   * @return date string
+   */
+  public static Date date(final String backup) {
+    return DateTime.parse(backup.replaceAll("^.+-(" + DATE + ")$", "$1"));
   }
 
   /**
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/core/Events.java basex-8.2.3/basex-core/src/main/java/org/basex/core/Events.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/core/Events.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/core/Events.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,114 +0,0 @@
-package org.basex.core;
-
-import static org.basex.core.Text.*;
-import static org.basex.util.Token.*;
-
-import java.io.*;
-import java.util.*;
-
-import org.basex.io.*;
-import org.basex.io.in.DataInput;
-import org.basex.io.out.DataOutput;
-import org.basex.server.*;
-import org.basex.util.*;
-
-/**
- * This class organizes all known events.
- *
- * @author BaseX Team 2005-15, BSD License
- * @author Christian Gruen
- * @author Roman Raedle
- * @author Andreas Weiler
- */
-public final class Events extends HashMap<String, Sessions> {
-  /** Event file. */
-  private final IOFile file = new IOFile(Prop.HOME, IO.BASEXSUFFIX + "events");
-
-  /**
-   * Constructor.
-   */
-  public Events() {
-    if(!file.exists()) return;
-
-    try(final DataInput in = new DataInput(file)) {
-      final int s = in.readNum();
-      for(int u = 0; u < s; ++u) put(string(in.readToken()), new Sessions());
-    } catch(final IOException ex) {
-      Util.errln(ex);
-    }
-  }
-
-  /**
-   * Creates an event.
-   * @param name event name
-   * @return success flag
-   */
-  public synchronized boolean create(final String name) {
-    final boolean b = put(name, new Sessions()) == null;
-    if(b) write();
-    return b;
-  }
-
-  /**
-   * Drops an event.
-   * @param name event name
-   * @return success flag
-   */
-  public synchronized boolean drop(final String name) {
-    final boolean b = remove(name) != null;
-    if(b) write();
-    return b;
-  }
-
-  /**
-   * Writes global permissions to disk.
-   */
-  private void write() {
-    try(final DataOutput out = new DataOutput(file)) {
-      out.writeNum(size());
-      for(final String name : keySet()) out.writeToken(token(name));
-    } catch(final IOException ex) {
-      Util.debug(ex);
-    }
-  }
-
-  /**
-   * Returns information on all events.
-   * @return information on all events.
-   */
-  public synchronized String info() {
-    final TokenBuilder tb = new TokenBuilder();
-    tb.addExt(EVENTS_X, size()).add(size() == 0 ? DOT : COL);
-
-    final String[] names = keySet().toArray(new String[size()]);
-    Arrays.sort(names);
-    for(final String n : names) tb.add(NL).add(LI).add(n);
-    return tb.toString();
-  }
-
-  /**
-   * Notifies the watching sessions about an event.
-   * @param ctx database context
-   * @param name name
-   * @param msg message
-   * @return success flag
-   */
-  public synchronized boolean notify(final Context ctx, final byte[] name, final byte[] msg) {
-    final Sessions sess = get(string(name));
-    // event was not found
-    if(sess == null) return false;
-
-    // refresh timestamp for last interaction
-    for(final ClientListener srv : sess) {
-      // ignore active client
-      if(srv == ctx.listener) continue;
-      try {
-        srv.notify(name, msg);
-      } catch(final IOException ex) {
-        // remove client if event could not be delivered
-        sess.remove(srv);
-      }
-    }
-    return true;
-  }
-}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/core/locks/DBLocking.java basex-8.2.3/basex-core/src/main/java/org/basex/core/locks/DBLocking.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/core/locks/DBLocking.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/core/locks/DBLocking.java	2015-07-14 10:54:40.000000000 +0000
@@ -5,6 +5,7 @@
 import java.util.*;
 import java.util.Map.Entry;
 import java.util.concurrent.*;
+import java.util.concurrent.atomic.*;
 import java.util.concurrent.locks.*;
 
 import org.basex.core.*;
@@ -41,8 +42,6 @@
   public static final String ADMIN = PREFIX + "ADMIN";
   /** Special lock identifier for backup commands. */
   public static final String BACKUP = PREFIX + "BACKUP";
-  /** Special lock identifier for event commands. */
-  public static final String EVENT = PREFIX + "EVENT";
   /** Special lock identifier for repository commands. */
   public static final String REPO = PREFIX + "REPO";
 
@@ -67,7 +66,7 @@
   /** Stores one lock for each object used for locking. */
   private final Map<String, ReentrantReadWriteLock> locks = new HashMap<>();
   /** Stores lock usage counters for each object used for locking. */
-  private final Map<String, Integer> lockUsage = new HashMap<>();
+  private final Map<String, AtomicInteger> lockUsage = new HashMap<>();
   /**
    * Currently running transactions.
    * Used as monitor for atomizing access to {@link #queue}.
@@ -139,7 +138,9 @@
       }
       // global read locking
       if(read == null) {
-        while(localWriters > 0) {
+        while(localWriters > 0 &&
+            // We're the only writer, allow global read lock anyway
+            !(1 == localWriters && !(null == write || write.isEmpty()))) {
           try {
             globalLock.wait();
           } catch(final InterruptedException ex) {
@@ -247,10 +248,13 @@
    * @param lock Lock to set used
    */
   private void setLockUsed(final String lock) {
-    synchronized(lockUsage) {
-      Integer usage = lockUsage.get(lock);
-      if(usage == null) usage = 0;
-      lockUsage.put(lock, ++usage);
+    synchronized(locks) {
+      final AtomicInteger usage = lockUsage.get(lock);
+      if(usage == null) {
+        lockUsage.put(lock, new AtomicInteger(1));
+      } else {
+        usage.incrementAndGet();
+      }
     }
   }
 
@@ -259,14 +263,11 @@
    * @param object Object to test
    */
   private void unsetLockIfUnused(final String object) {
-    synchronized(lockUsage) {
-      Integer usage = lockUsage.get(object);
-      assert usage != null;
-      if(--usage == 0) {
+    synchronized(locks) {
+      final AtomicInteger usage = lockUsage.get(object);
+      if(usage.decrementAndGet() == 0) {
         locks.remove(object);
         lockUsage.remove(object);
-      } else {
-        lockUsage.put(object, usage);
       }
     }
   }
@@ -283,8 +284,10 @@
     sb.append(ind + "Transactions running: " + transactions + NL);
     sb.append(ind + "Transaction queue: " + queue + NL);
     sb.append(ind + "Held locks by object:" + NL);
-    for(final Entry<String, ReentrantReadWriteLock> e : locks.entrySet())
-      sb.append(ind + ind + e.getKey() + " -> " + e.getValue() + NL);
+    synchronized(locks) {
+      for(final Entry<String, ReentrantReadWriteLock> e : locks.entrySet())
+        sb.append(ind + ind + e.getKey() + " -> " + e.getValue() + NL);
+    }
     sb.append(ind + "Held write locks by transaction:" + NL);
     for(final Long thread : writeLocked.keySet())
       sb.append(ind + ind + thread + " -> " + writeLocked.get(thread) + NL);
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/core/MainOptions.java basex-8.2.3/basex-core/src/main/java/org/basex/core/MainOptions.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/core/MainOptions.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/core/MainOptions.java	2015-07-14 10:54:40.000000000 +0000
@@ -121,8 +121,6 @@
   public static final NumberOption TAILCALLS = new NumberOption("TAILCALLS", 256);
   /** Favor global database when opening resources. */
   public static final BooleanOption DEFAULTDB = new BooleanOption("DEFAULTDB", false);
-  /** Caches the query results. */
-  public static final BooleanOption CACHEQUERY = new BooleanOption("CACHEQUERY", false);
   /** Forces database creation for unknown documents. */
   public static final BooleanOption FORCECREATE = new BooleanOption("FORCECREATE", false);
   /** Validate string inputs. */
@@ -163,9 +161,6 @@
 
   // Other
 
-  /** Hidden: maximum number of hits to be displayed in the GUI (will be overwritten). */
-  public static final NumberOption MAXHITS = new NumberOption("MAXHITS", -1);
-
   /** Options that are adopted from parent options. */
   private static final Option<?>[] PARENT = { CHOP, INTPARSE, STRIPNS, DTD, XINCLUDE, CATFILE };
 
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/core/parse/Commands.java basex-8.2.3/basex-core/src/main/java/org/basex/core/parse/Commands.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/core/parse/Commands.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/core/parse/Commands.java	2015-07-14 10:54:40.000000000 +0000
@@ -31,8 +31,6 @@
   String CREATE_BACKUP = "create-backup";
   /** Command string: "create-db". */
   String CREATE_DB = "create-db";
-  /** Command string: "create-event". */
-  String CREATE_EVENT = "create-event";
   /** Command string: "create-index". */
   String CREATE_INDEX = "create-index";
   /** Command string: "create-user". */
@@ -43,8 +41,6 @@
   String DROP_BACKUP = "drop-backup";
   /** Command string: "drop-db". */
   String DROP_DB = "drop-db";
-  /** Command string: "drop-event". */
-  String DROP_EVENT = "drop-event";
   /** Command string: "drop-index". */
   String DROP_INDEX = "drop-index";
   /** Command string: "drop-user". */
@@ -109,8 +105,6 @@
   String SET = "set";
   /** Command string: "show-backups". */
   String SHOW_BACKUPS = "show-backups";
-  /** Command string: "show-events". */
-  String SHOW_EVENTS = "show-events";
   /** Command string: "show-sessions". */
   String SHOW_SESSIONS = "show-sessions";
   /** Command string: "show-users". */
@@ -154,15 +148,15 @@
   String COMMAND = "command";
 
   /** Create commands. */
-  enum CmdCreate { DATABASE, DB, INDEX, USER, BACKUP, EVENT }
+  enum CmdCreate { DATABASE, DB, INDEX, USER, BACKUP }
   /** Info commands. */
   enum CmdInfo { NULL, DATABASE, DB, INDEX, STORAGE }
   /** Drop commands. */
-  enum CmdDrop { DATABASE, DB, INDEX, USER, BACKUP, EVENT }
+  enum CmdDrop { DATABASE, DB, INDEX, USER, BACKUP }
   /** Optimize commands. */
   enum CmdOptimize { NULL, ALL }
   /** Show commands. */
-  enum CmdShow { SESSIONS, USERS, BACKUPS, EVENTS }
+  enum CmdShow { SESSIONS, USERS, BACKUPS }
   /** Permission commands. */
   enum CmdPerm { NONE, READ, WRITE, CREATE, ADMIN }
   /** Index types. */
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/core/parse/StringParser.java basex-8.2.3/basex-core/src/main/java/org/basex/core/parse/StringParser.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/core/parse/StringParser.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/core/parse/StringParser.java	2015-07-14 10:54:40.000000000 +0000
@@ -79,8 +79,6 @@
             return new CreateIndex(consume(CmdIndex.class, cmd));
           case USER:
             return new CreateUser(name(cmd), password());
-          case EVENT:
-            return new CreateEvent(name(cmd));
         }
         break;
       case COPY:
@@ -144,8 +142,6 @@
             return new DropUser(glob(cmd), key(ON, null) ? glob(cmd) : null);
           case BACKUP:
             return new DropBackup(glob(cmd));
-          case EVENT:
-            return new DropEvent(name(cmd));
         }
         break;
       case OPTIMIZE:
@@ -193,8 +189,6 @@
             return new ShowUsers(key(ON, null) ? name(cmd) : null);
           case BACKUPS:
             return new ShowBackups();
-          case EVENTS:
-            return new ShowEvents();
         }
         break;
       case GRANT:
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/core/parse/XMLParser.java basex-8.2.3/basex-core/src/main/java/org/basex/core/parse/XMLParser.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/core/parse/XMLParser.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/core/parse/XMLParser.java	2015-07-14 10:54:40.000000000 +0000
@@ -12,6 +12,7 @@
 import org.basex.io.*;
 import org.basex.query.*;
 import org.basex.query.iter.*;
+import org.basex.query.value.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.node.*;
 import org.basex.util.*;
@@ -55,9 +56,10 @@
    * Returns a command.
    * @param root command node
    * @return command
+   * @throws IOException I/O exception
    * @throws QueryException query exception
    */
-  private Command command(final Item root) throws QueryException {
+  private Command command(final Item root) throws IOException, QueryException {
     final String e = ((ANode) root).qname().toJava().toString();
     if(e.equals(ADD) && check(root, PATH + '?', '<' + INPUT))
       return new Add(value(root, PATH), xml(root));
@@ -77,8 +79,6 @@
       return new CreateBackup(value(root, NAME));
     if(e.equals(CREATE_DB) && check(root, NAME, '<' + INPUT + '?'))
       return new CreateDB(value(root, NAME), xml(root));
-    if(e.equals(CREATE_EVENT) && check(root, NAME + '?'))
-      return new CreateEvent(value(root, NAME));
     if(e.equals(CREATE_INDEX) && check(root, TYPE))
       return new CreateIndex(value(root, TYPE));
     if(e.equals(CREATE_USER) && check(root, NAME, '#' + PASSWORD + '?'))
@@ -89,8 +89,6 @@
       return new DropBackup(value(root, NAME));
     if(e.equals(DROP_DB) && check(root, NAME))
       return new DropDB(value(root, NAME));
-    if(e.equals(DROP_EVENT) && check(root, NAME))
-      return new DropEvent(value(root, NAME));
     if(e.equals(DROP_INDEX) && check(root, TYPE))
       return new DropIndex(value(root, TYPE));
     if(e.equals(DROP_USER) && check(root, NAME, PATTERN + '?'))
@@ -117,7 +115,7 @@
       return new InfoIndex(value(root, TYPE));
     if(e.equals(INFO_STORAGE) && check(root, '#' + QUERY + '?'))
       return new InfoStorage(value(root));
-    if(e.equals(KILL) && check(root, TARGET + '?'))
+    if(e.equals(KILL) && check(root, TARGET))
       return new Kill(value(root, TARGET));
     if(e.equals(LIST) && check(root, NAME + '?', PATH + '?'))
       return new List(value(root, NAME), value(root, PATH));
@@ -155,8 +153,6 @@
       return new Set(value(root, OPTION), value(root));
     if(e.equals(SHOW_BACKUPS) && check(root))
       return new ShowBackups();
-    if(e.equals(SHOW_EVENTS) && check(root))
-      return new ShowEvents();
     if(e.equals(SHOW_SESSIONS) && check(root))
       return new ShowSessions();
     if(e.equals(SHOW_USERS) && check(root, DATABASE + '?'))
@@ -174,7 +170,7 @@
    * Returns the value of the specified attribute.
    * @param root root node
    * @param att name of attribute
-   * @return query exception
+   * @return value
    * @throws QueryException query exception
    */
   private String value(final Item root, final String att) throws QueryException {
@@ -184,7 +180,7 @@
   /**
    * Returns a string value (text node).
    * @param root root node
-   * @return query exception
+   * @return string value
    * @throws QueryException query exception
    */
   private String value(final Item root) throws QueryException {
@@ -194,23 +190,24 @@
   /**
    * Returns a password (text node).
    * @param root root node
-   * @return query exception
+   * @return password string
    * @throws QueryException query exception
    */
   private String password(final Item root) throws QueryException {
     final String pw = execute("string(.)", root);
-    return pw.isEmpty() && pwReader != null ? pwReader.password() : "";
+    return pw.isEmpty() && pwReader != null ? pwReader.password() : pw;
   }
 
   /**
    * Returns an xml value (text node).
    * @param root root node
-   * @return query exception
+   * @return xml value
+   * @throws IOException I/O exception
    * @throws QueryException query exception
    */
-  private String xml(final Item root) throws QueryException {
+  private String xml(final Item root) throws IOException, QueryException {
     try(final QueryProcessor qp = new QueryProcessor("node()", ctx)) {
-      return qp.context(root).execute().toString().trim();
+      return qp.context(root).value().serialize().toString().trim();
     }
   }
 
@@ -218,7 +215,7 @@
    * Executes the specified query and returns a string representation.
    * @param query query
    * @param context context node
-   * @return query exception
+   * @return string representation
    * @throws QueryException query exception
    */
   private String execute(final String query, final Item context) throws QueryException {
@@ -289,19 +286,20 @@
     }
 
     // run query
+    final Value mv = ma.value(), ov = oa.value();
     try(final QueryProcessor qp = new QueryProcessor(tb.toString(), ctx).context(root)) {
-      qp.bind("A", ma.value()).bind("O", oa.value());
-      if(!qp.execute().toString().isEmpty()) return true;
+      qp.bind("A", mv).bind("O", ov);
+      if(qp.value().size() != 0) return true;
     }
     // build error string
     final TokenBuilder syntax = new TokenBuilder();
     final byte[] nm = ((ANode) root).qname().string();
     syntax.reset().add('<').add(nm);
-    for(final Item i : ma) {
+    for(final Item i : mv) {
       final byte[] a = i.string(null);
       syntax.add(' ').add(a).add("=\"...\"");
     }
-    for(final Item i : oa) {
+    for(final Item i : ov) {
       final byte[] a = i.string(null);
       syntax.add(" (").add(a).add("=\"...\")");
     }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/core/Sandbox.java basex-8.2.3/basex-core/src/main/java/org/basex/core/Sandbox.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/core/Sandbox.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/core/Sandbox.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,172 @@
+package org.basex.core;
+
+import static org.basex.core.Text.*;
+
+import java.io.*;
+import java.util.concurrent.*;
+
+import org.basex.*;
+import org.basex.api.client.*;
+import org.basex.core.users.*;
+import org.basex.io.*;
+import org.basex.io.out.*;
+import org.basex.util.*;
+import org.basex.util.list.*;
+
+/**
+ * If this class is extended, tests will be run in a sandbox.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Christian Gruen
+ */
+public abstract class Sandbox {
+  /** Database port. */
+  protected static final int DB_PORT = 9996;
+
+  /** Default output stream. */
+  public static final PrintStream OUT = System.out;
+  /** Default error stream. */
+  public static final PrintStream ERR = System.err;
+  /** Null output stream. */
+  public static final PrintStream NULL = new PrintStream(new NullOutput());
+  /** Test name. */
+  protected static final String NAME = Util.className(Sandbox.class);
+  /** Database context. */
+  protected static Context context;
+
+  /**
+   * Creates the sandbox.
+   */
+  public static void initSandbox() {
+    final IOFile sb = sandbox();
+    sb.delete();
+    if(!sb.md()) throw Util.notExpected("Sandbox could not be created.");
+
+    final String path = sb.path();
+    Prop.put(StaticOptions.DBPATH, path + "/data");
+    Prop.put(StaticOptions.WEBPATH, path + "/webapp");
+    Prop.put(StaticOptions.RESTXQPATH, path + "/webapp");
+    Prop.put(StaticOptions.REPOPATH, path + "/repo");
+    Prop.put(StaticOptions.SERVERPORT, DB_PORT);
+    context = new Context();
+  }
+
+  /**
+   * Removes test databases and closes the database context.
+   */
+  public static void finishSandbox() {
+    context.close();
+    Prop.remove(StaticOptions.DBPATH);
+    Prop.remove(StaticOptions.WEBPATH);
+    Prop.remove(StaticOptions.RESTXQPATH);
+    Prop.remove(StaticOptions.REPOPATH);
+    Prop.remove(StaticOptions.SERVERPORT);
+    if(!sandbox().delete()) throw Util.notExpected("Sandbox could not be created.");
+  }
+
+  /**
+   * Creates a new, sandboxed server instance.
+   * @param args additional arguments
+   * @return server instance
+   * @throws IOException I/O exception
+   */
+  public static BaseXServer createServer(final String... args) throws IOException {
+    try {
+      System.setOut(NULL);
+      final StringList sl = new StringList("-z", "-p" + DB_PORT, "-q");
+      for(final String arg : args) sl.add(arg);
+      final BaseXServer server = new BaseXServer(sl.finish());
+      server.context.soptions.set(StaticOptions.DBPATH, sandbox().path());
+      return server;
+    } finally {
+      System.setOut(OUT);
+    }
+  }
+
+  /**
+   * Stops a server instance.
+   * @param server server
+   * @throws IOException I/O exception
+   */
+  public static void stopServer(final BaseXServer server) throws IOException {
+    try {
+      System.setOut(NULL);
+      if(server != null) server.stop();
+    } finally {
+      System.setOut(OUT);
+    }
+  }
+
+  /**
+   * Creates a client instance.
+   * @param login optional login data
+   * @return client instance
+   * @throws IOException I/O exception
+   */
+  public static ClientSession createClient(final String... login) throws IOException {
+    final String user = login.length > 0 ? login[0] : UserText.ADMIN;
+    final String pass = login.length > 1 ? login[1] : UserText.ADMIN;
+    return new ClientSession(S_LOCALHOST, DB_PORT, user, pass);
+  }
+
+  /**
+   * Returns the sandbox database path.
+   * @return database path
+   */
+  public static IOFile sandbox() {
+    return new IOFile(Prop.TMP, NAME);
+  }
+
+  /**
+   * Normalizes newlines in a query result.
+   * @param result input string
+   * @return normalized string
+   */
+  public static String normNL(final String result) {
+    return result.replaceAll("(\r?\n|\r) *", "\n");
+  }
+
+  /** Client. */
+  public static final class Client extends Thread {
+    /** Start signal. */
+    private final CountDownLatch startSignal;
+    /** Stop signal. */
+    private final CountDownLatch stopSignal;
+    /** Client session. */
+    private final ClientSession session;
+    /** Command string. */
+    private final Command cmd;
+    /** Fail flag. */
+    public String error;
+
+    /**
+     * Client constructor.
+     * @param c command string to execute
+     * @param start start signal
+     * @param stop stop signal
+     * @throws IOException I/O exception while establishing the session
+     */
+    public Client(final Command c, final CountDownLatch start, final CountDownLatch stop)
+        throws IOException {
+
+      session = createClient();
+      cmd = c;
+      startSignal = start;
+      stopSignal = stop;
+      start();
+    }
+
+    @Override
+    public void run() {
+      try {
+        if(startSignal != null) startSignal.await();
+        session.execute(cmd);
+        session.close();
+      } catch(final Throwable ex) {
+        error = "\n" + cmd + '\n' + ex;
+      } finally {
+        if(stopSignal != null) stopSignal.countDown();
+      }
+    }
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/core/StaticOptions.java basex-8.2.3/basex-core/src/main/java/org/basex/core/StaticOptions.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/core/StaticOptions.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/core/StaticOptions.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,7 +1,5 @@
 package org.basex.core;
 
-import static org.basex.util.Prop.*;
-
 import java.util.*;
 
 import org.basex.io.*;
@@ -17,7 +15,7 @@
  */
 public final class StaticOptions extends Options {
   /** Indicates if the user's home directory has been chosen as home directory. */
-  private static final boolean USERHOME = HOME.equals(Prop.USERHOME);
+  private static final boolean USERHOME = Prop.HOME.equals(Prop.USERHOME);
 
   /** Comment: written to options file. */
   public static final Comment C_GENERAL = new Comment("General Options");
@@ -26,12 +24,12 @@
   public static final BooleanOption DEBUG = new BooleanOption("DEBUG", false);
   /** Database path. */
   public static final StringOption DBPATH = new StringOption("DBPATH",
-    HOME + (USERHOME ? NAME + "Data" : "data"));
+      Prop.HOME + (USERHOME ? Prop.NAME + "Data" : "data"));
   /** Package repository path. */
   public static final StringOption REPOPATH = new StringOption("REPOPATH",
-    HOME + (USERHOME ? NAME + "Repo" : "repo"));
+      Prop.HOME + (USERHOME ? Prop.NAME + "Repo" : "repo"));
   /** Language name. */
-  public static final StringOption LANG = new StringOption("LANG", language);
+  public static final StringOption LANG = new StringOption("LANG", Prop.language);
   /** Flag to include key names in the language strings. */
   public static final BooleanOption LANGKEYS = new BooleanOption("LANGKEYS", false);
   /** Applied locking algorithm: local (database) vs. global (process) locking. */
@@ -46,8 +44,6 @@
   public static final NumberOption PORT = new NumberOption("PORT", 1984);
   /** Server: port, used for binding the server. */
   public static final NumberOption SERVERPORT = new NumberOption("SERVERPORT", 1984);
-  /** Server: port, used for sending events. */
-  public static final NumberOption EVENTPORT = new NumberOption("EVENTPORT", 1985);
   /** Default user. */
   public static final StringOption USER = new StringOption("USER", "");
   /** Default password. */
@@ -79,11 +75,13 @@
 
   /** Web path. */
   public static final StringOption WEBPATH = new StringOption("WEBPATH",
-    HOME + (USERHOME ? NAME + "Web" : "webapp"));
+      Prop.HOME + (USERHOME ? Prop.NAME + "Web" : "webapp"));
   /** REST path (relative to web path). */
   public static final StringOption RESTPATH = new StringOption("RESTPATH", "");
   /** RESTXQ path (relative to web path). */
   public static final StringOption RESTXQPATH = new StringOption("RESTXQPATH", "");
+  /** Cache RESTXQ paths. */
+  public static final BooleanOption CACHERESTXQ = new BooleanOption("CACHERESTXQ", false);
   /** Local (embedded) mode. */
   public static final BooleanOption HTTPLOCAL = new BooleanOption("HTTPLOCAL", false);
   /** Port for stopping the web server. */
@@ -109,26 +107,26 @@
    * @param file if {@code true}, options will be read from disk
    */
   StaticOptions(final boolean file) {
-    super(file ? new IOFile(HOME, IO.BASEXSUFFIX) : null);
+    super(file ? new IOFile(Prop.HOME, IO.BASEXSUFFIX) : null);
     setSystem();
 
     // set some static options
-    language = get(LANG);
-    langkeys = get(LANGKEYS);
-    debug = get(DEBUG);
+    Prop.language = get(LANG);
+    Prop.langkeys = get(LANGKEYS);
+    Prop.debug = get(DEBUG);
     final String ph = get(PROXYHOST);
     if(!ph.isEmpty()) {
-      setSystem("http.proxyHost", ph);
-      setSystem("https.proxyHost", ph);
+      Prop.setSystem("http.proxyHost", ph);
+      Prop.setSystem("https.proxyHost", ph);
     }
     final String pp = Integer.toString(get(PROXYPORT));
     if(!pp.equals("0")) {
-      setSystem("http.proxyPort", pp);
-      setSystem("https.proxyPort", pp);
+      Prop.setSystem("http.proxyPort", pp);
+      Prop.setSystem("https.proxyPort", pp);
     }
     final String nph = get(NONPROXYHOSTS);
     if(!nph.isEmpty()) {
-      setSystem("http.nonProxyHosts", nph);
+      Prop.setSystem("http.nonProxyHosts", nph);
     }
     if(get(IGNORECERT)) IOUrl.ignoreCert();
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/core/Text.java basex-8.2.3/basex-core/src/main/java/org/basex/core/Text.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/core/Text.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/core/Text.java	2015-07-14 10:54:40.000000000 +0000
@@ -55,7 +55,7 @@
   String S_STANDALONE = "Standalone";
   /** Start information. */
   String  S_LOCALINFO =
-    " [-bcdioqrRsuvVwxXz] [input]" + NL +
+    " [-bcdiIoqrRstuvVwxXz] [input]" + NL +
     "  [input]     XQuery or command file, or query string" + NL +
     "  -b<pars>    Bind external query variables" + NL +
     "  -c<input>   Execute commands from file or string" + NL +
@@ -79,7 +79,7 @@
   String S_CLIENT = "Client";
   /** Client start information. */
   String S_CLIENTINFO =
-    " [-bcdinopPqrRsUvVwxz] [input]" + NL +
+    " [-bcdiInopPqrRsUvVwxXz] [input]" + NL +
     "  [input]     XQuery or command file, or query string" + NL +
     "  -b<pars>    Bind external query variables" + NL +
     "  -c<input>   Execute commands from file or string" + NL +
@@ -105,11 +105,10 @@
   String S_SERVER = "Server";
   /** Server start information. */
   String S_SERVERINFO =
-    " [-cdeinpSz] [stop]" + NL +
+    " [-cdinpSz] [stop]" + NL +
     "  stop      Stop running server" + NL +
     "  -c<cmds>  Execute initial database commands" + NL +
     "  -d        Activate debugging mode" + NL +
-    "  -e<port>  Set event port" + NL +
     "  -n<name>  Set host the server is bound to" + NL +
     "  -p<port>  Set server port" + NL +
     "  -S        Start as service" + NL +
@@ -124,10 +123,9 @@
 
   /** HTTP information. */
   String S_HTTPINFO =
-    " [-dehlnpPsSUz] [stop]" + NL +
+    " [-dhlnpPsSUz] [stop]" + NL +
     "  stop      Stop running server" + NL +
     "  -d        Activate debugging mode" + NL +
-    "  -e<port>  Set event port" + NL +
     "  -h<port>  Set port of HTTP server" + NL +
     "  -l        Start in local mode" + NL +
     "  -n<name>  Set host name of database server" + NL +
@@ -241,19 +239,23 @@
   // SERVER ===================================================================
 
   /** Server was started. */
-  String SRV_STARTED_PORT_X = lang("srv_started_port_%");
+  String PORT_X = " (" + lang("port") + ": %).";
+  /** Server was started. */
+  String SRV_STARTED_PORT_X = lang("srv_started") + PORT_X;
   /** Server was stopped. */
-  String SRV_STOPPED_PORT_X = lang("srv_stopped_port_%");
+  String SRV_STOPPED_PORT_X = lang("srv_stopped") + PORT_X;
+  /** Server is running or permission was denied. */
+  String SRV_RUNNING = lang("srv_running") + '.';
   /** Server is running or permission was denied. */
-  String SRV_RUNNING = lang("srv_running");
-  /** Ports was specified twice. */
-  String PORT_TWICE_X = lang("port_twice_%");
+  String SRV_RUNNING_X = lang("srv_running") + PORT_X;
+  /** Connection error. */
+  String CONNECTION_ERROR = lang("connection_error") + '.';
+  /** Connection error. */
+  String CONNECTION_ERROR_X = lang("connection_error") + PORT_X;
   /** Unknown host. */
   String UNKNOWN_HOST_X = lang("unknown_host_x");
   /** Timeout exceeded. */
   String TIMEOUT_EXCEEDED = lang("timeout_exceeded");
-  /** Connection error. */
-  String CONNECTION_ERROR = lang("connection_error");
   /** Access denied. */
   String ACCESS_DENIED = lang("access_denied");
   /** User name. */
@@ -277,15 +279,13 @@
   /** Command help. */
   String[] HELPCREATE = {
     "[" + CmdCreate.BACKUP + '|' + CmdCreate.DATABASE + '|' +
-    CmdCreate.EVENT + '|' + CmdCreate.INDEX + '|' + CmdCreate.USER + "] [...]",
+    CmdCreate.INDEX + '|' + CmdCreate.USER + "] [...]",
     lang("c_create1"),
     lang("c_create2") + NL +
     LI + CmdDrop.BACKUP + " [" + S_NAME + "]:" + NL +
     "  " + lang("c_create22", S_NAME) + NL +
     LI + CmdCreate.DATABASE + " [" + S_NAME + "] ([" + S_INPUT + "]):"  + NL +
     "  " + lang("c_create21", S_NAME, S_INPUT) + NL +
-    LI + CmdCreate.EVENT + " [" + S_NAME + "]: " + NL +
-    "  " + lang("c_create25") + NL +
     LI + CmdCreate.INDEX + " [" + CmdIndex.TEXT + '|' + CmdIndex.ATTRIBUTE +
     '|' + CmdIndex.FULLTEXT + "]:" + NL +
     "  " + lang("c_create23") + NL +
@@ -345,7 +345,7 @@
   };
   /** Command help. */
   String[] HELPDROP = {
-    "[" + CmdDrop.BACKUP + '|' + CmdDrop.DATABASE + '|' + CmdDrop.EVENT + '|' +
+    "[" + CmdDrop.BACKUP + '|' + CmdDrop.DATABASE + '|' +
       CmdDrop.INDEX + '|' + CmdDrop.USER + "] [...]",
     lang("c_drop1"),
     lang("c_drop2") + NL +
@@ -353,8 +353,6 @@
       "  " + lang("c_drop24") + NL +
     LI + CmdDrop.DATABASE + " [" + S_NAME + "]:" + NL +
       "  " + lang("c_drop21") + NL +
-    LI + CmdDrop.EVENT + " [" + S_NAME + "]:" + NL +
-      "  " + lang("c_drop25") + NL +
     LI + CmdDrop.INDEX + " [" + CmdIndex.TEXT + '|' +
       CmdIndex.ATTRIBUTE + '|' + CmdIndex.FULLTEXT + "]:" + NL +
       "  " + lang("c_drop22") + NL +
@@ -413,11 +411,9 @@
   };
   /** Command help. */
   String[] HELPSHOW = {
-    "[" + CmdShow.BACKUPS + '|' + CmdShow.EVENTS +
-    '|' + CmdShow.SESSIONS + '|' + CmdShow.USERS + ']',
+    "[" + CmdShow.BACKUPS + '|' + CmdShow.SESSIONS + '|' + CmdShow.USERS + ']',
     lang("c_show1"),
     lang("c_show21") + NL +
-    LI + CmdShow.EVENTS + ": " + lang("c_show26") + NL +
     LI + CmdShow.SESSIONS + ": " + lang("c_show23") + NL +
     LI + CmdShow.USERS + " (" + ON + " [database]): " + lang("c_show24") + NL +
     LI + CmdShow.BACKUPS + ": " + lang("c_show25")
@@ -573,7 +569,7 @@
   String DB_NOT_FOUND_X = lang("db_not_found_%");
   /** Name invalid. */
   String NAME_INVALID_X = lang("name_invalid_%");
-  /** Paht invalid. */
+  /** Path invalid. */
   String PATH_INVALID_X = lang("path_invalid_%");
   /** Database pinned. */
   String DB_PINNED_X = lang("db_pinned_%");
@@ -692,8 +688,6 @@
 
   /** Show sessions. */
   String SESSIONS_X = lang("sessions_%");
-  /** Show events. */
-  String EVENTS_X = lang("events_%");
   /** Show packages. */
   String PACKAGES_X = lang("packages_%");
   /** Permission required. */
@@ -726,22 +720,6 @@
   String SESSIONS_KILLED_X = lang("sessions_killed_%");
   /** User kills itself. */
   String KILL_SELF_X = lang("kill_self_%");
-  /** Event dropped. */
-  String EVENT_DROPPED_X = lang("event_dropped_%");
-  /** Event added. */
-  String EVENT_CREATED_X = lang("event_created_%");
-  /** Event not found. */
-  String EVENT_UNKNOWN_X = lang("event_unknown_%");
-  /** Already watching the event. */
-  String EVENT_WATCHED_X = lang("event_watched_%");
-  /** Nothing to unwatch. */
-  String EVENT_NOT_WATCHED_X = lang("event_not_watched_%");
-  /** Event already exists. */
-  String EVENT_EXISTS_X = lang("event_exists_%");
-  /** Watch Event. */
-  String WATCHING_EVENT_X = lang("watching_event_%");
-  /** Unwatch Event. */
-  String UNWATCHING_EVENT_X = lang("unwatching_event_%");
   /** Package deleted. */
   String PKG_DELETED_X = lang("pkg_deleted_%");
   /** Package installed. */
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/core/users/User.java basex-8.2.3/basex-core/src/main/java/org/basex/core/users/User.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/core/users/User.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/core/users/User.java	2015-07-14 10:54:40.000000000 +0000
@@ -201,10 +201,10 @@
   /**
    * Sets the permission.
    * @param prm permission
-   * @param pattern database pattern (can be {@code null})
+   * @param pattern database pattern (can be empty)
    */
   public synchronized void perm(final Perm prm, final String pattern) {
-    if(pattern == null) {
+    if(pattern.isEmpty()) {
       perm = prm;
     } else {
       locals.put(pattern, prm);
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/core/users/Users.java basex-8.2.3/basex-core/src/main/java/org/basex/core/users/Users.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/core/users/Users.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/core/users/Users.java	2015-07-14 10:54:40.000000000 +0000
@@ -117,7 +117,7 @@
    * Sets the permission of a user.
    * @param user user
    * @param prm permission
-   * @param pattern database pattern (can be {@code null})
+   * @param pattern database pattern (can be empty)
    */
   public static void perm(final User user, final Perm prm, final String pattern) {
     user.perm(prm, pattern);
@@ -135,13 +135,13 @@
   }
 
   /**
-   * Drops a user from the list.
+   * Drops a user from the list, or removes the specified pattern if non-empty.
    * @param user user reference
-   * @param pattern database pattern (can be {@code null})
+   * @param pattern database pattern (can be empty)
    * @return success flag
    */
   public synchronized boolean drop(final User user, final String pattern) {
-    if(pattern == null) {
+    if(pattern.isEmpty()) {
       if(users.remove(user.name()) == null) return false;
     } else {
       user.remove(pattern);
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/data/atomic/AtomicUpdateCache.java basex-8.2.3/basex-core/src/main/java/org/basex/data/atomic/AtomicUpdateCache.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/data/atomic/AtomicUpdateCache.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/data/atomic/AtomicUpdateCache.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,519 +0,0 @@
-package org.basex.data.atomic;
-
-import java.util.*;
-
-import org.basex.data.*;
-import org.basex.util.*;
-import org.basex.util.hash.*;
-
-/**
- * Implementation of the Atomic Update Cache (AUC).
- *
- * <p>A container/list for atomic updates. Updates must be added from the lowest to
- * the highest PRE value (regarding the location of the update). Updates are finally
- * applied by this container from the highest to the lowest PRE value (reverse document
- * order) to support efficient structural bulk updates etc.</p>
- *
- * <p>If a collection of updates is carried out via the AUC there are several
- * benefits:</p>
- *
- * <ol>
- *   <li> Efficient distance adjustments after structural changes.</li>
- *   <li> Tree-Aware Updates (TAU): identification of superfluous updates (like updating
- *        the descendants of a deleted node).</li>
- *   <li> Resolution of text node adjacency.</li>
- *   <li> Merging of atomic updates to reduce number of I/Os. </li>
- * </ol>
- *
- * <p>To avoid ambiguity it is not allowed to add:</p>
- * <ul>
- * <li> more than one destructive update like {@link Delete} or {@link Replace} operating
- *      on the same node.</li>
- * <li> more than one {@link Rename} or {@link UpdateValue} operating
- *      on the same node.</li>
- * <li> sequences like [delete X, insert N at X]: This sequence would be carried out back
- * to front: first the insert, then the delete. This would lead to the inserted node N
- * being deleted by the 'delete X' statement. The correct order for this sequence would
- * be [insert N at X, delete X]. </li>
- * <li> and so forth ... see check() function for details. </li>
- * </ul>
- *
- * <p>Updates are added in a streaming fashion where the most recently added update is
- * remembered. This avoids additional traversals of the AUC during consistency checks and
- * further optimizations.</p>
- *
- * @author BaseX Team 2005-15, BSD License
- * @author Lukas Kircher
- */
-public final class AtomicUpdateCache {
-  /** List of structural updates (nodes are inserted to / deleted from the table. */
-  private final List<StructuralUpdate> struct = new ArrayList<>(1);
-  /** Value / non-structural updates like rename. */
-  private final List<BasicUpdate> val = new ArrayList<>(1);
-  /** Most recently added update buffer. Used to merge/discard updates and to detect
-   * inconsistencies on-the-fly eliminating the need to traverse all updates. */
-  private BasicUpdate recent;
-  /** Most recently added structural atomic update - if there is any. Used to calculate accumulated
-   * pre value shifts on-the-fly, as {@link BasicUpdate} don't carry this information. */
-  private BasicUpdate recentStruct;
-  /** Target data reference. */
-  public final Data data;
-
-  /**
-   * Constructor.
-   * @param data target data reference
-   */
-  public AtomicUpdateCache(final Data data) {
-    this.data = data;
-  }
-
-  /**
-   * Adds a delete atomic to the list.
-   * @param pre PRE value of the target node/update location
-   */
-  public void addDelete(final int pre) {
-    considerAtomic(Delete.getInstance(data, pre), false);
-  }
-
-  /**
-   * Adds an insert atomic to the list.
-   * @param pre PRE value of the target node/update location
-   * @param par new parent of the inserted nodes
-   * @param clip insertion sequence data clip
-   */
-  public void addInsert(final int pre, final int par, final DataClip clip) {
-    considerAtomic(clip.data.kind(clip.start) == Data.ATTR
-        ? InsertAttr.getInstance(pre, par, clip) : Insert.getInstance(pre, par, clip), false);
-  }
-
-  /**
-   * Adds a replace atomic to the list.
-   * @param pre PRE value of the target node/update location
-   * @param clip insertion sequence data clip
-   */
-  public void addReplace(final int pre, final DataClip clip) {
-    considerAtomic(Replace.getInstance(data, pre, clip), false);
-  }
-
-  /**
-   * Adds a rename atomic to the list.
-   * @param pre PRE value of the target node/update location
-   * @param name new name for the target node
-   * @param uri new uri for the target node
-   */
-  public void addRename(final int pre, final byte[] name, final byte[] uri) {
-    considerAtomic(Rename.getInstance(data, pre, name, uri), false);
-  }
-
-  /**
-   * Adds an updateValue atomic to the list.
-   * @param pre PRE value of the target node/update location
-   * @param value new value for the target node
-   */
-  public void addUpdateValue(final int pre, final byte[] value) {
-    considerAtomic(UpdateValue.getInstance(data, pre, value), false);
-  }
-
-  /**
-   * Resets the list.
-   */
-  public void clear() {
-    struct.clear();
-    val.clear();
-    recent = null;
-    recentStruct = null;
-  }
-
-  /**
-   * Adds an update to the corresponding list.
-   * @param candidate atomic update
-   * @param slack skip consistency checks etc. if true (used during text node merging)
-   */
-  private void considerAtomic(final BasicUpdate candidate, final boolean slack) {
-    // fill the one-atomic-update buffer
-    if(recent == null) {
-      recent = candidate;
-      if(recent instanceof StructuralUpdate)
-        recentStruct = candidate;
-      return;
-    }
-
-    if(candidate instanceof StructuralUpdate && recentStruct != null) {
-      ((StructuralUpdate) candidate).accumulatedShifts += recentStruct.accumulatedShifts();
-    }
-
-    // prepare & optimize incoming update
-    if(slack) {
-      add(candidate, false);
-    } else {
-      check(recent, candidate);
-      if(treeAwareUpdates(recent, candidate)) return;
-
-      final BasicUpdate m = recent.merge(data, candidate);
-      if(m != null) add(m, true);
-      else add(candidate, false);
-
-    }
-  }
-
-  /**
-   * Adds the given update to the updates/buffer depending on the type and whether it's
-   * been merged or not.
-   *
-   * @param bu update
-   * @param merged if true, the given update has been merged w/ the recent one
-   */
-  private void add(final BasicUpdate bu, final boolean merged) {
-    if(bu == null) return;
-
-    if(!merged) {
-      if(recent instanceof StructuralUpdate)
-        struct.add((StructuralUpdate) recent);
-      else val.add(recent);
-    }
-    recent = bu;
-    if(bu instanceof StructuralUpdate)
-      recentStruct = bu;
-  }
-
-  /**
-   * Flushes the buffer that contains the most previously added atomic update.
-   */
-  private void flush() {
-    if(recent != null) {
-      add(recent, false);
-      recent = null;
-      recentStruct = null;
-    }
-  }
-
-  /**
-   * Returns the number of structural updates.
-   * @return number of structural updates
-   */
-  public int updatesSize() {
-    flush();
-    return struct.size() + val.size();
-  }
-
-  /**
-   * Checks the given sequence of two updates for violations.
-   *
-   * Updates must be ordered strictly from the lowest to the highest PRE value.
-   * Deletes must follow inserts.
-   *
-   * A single node must not be affected by more than one {@link Rename},
-   * {@link UpdateValue} operation.
-   *
-   * A single node must not be affected by more than one destructive operation. These
-   * operations include {@link Replace}, {@link Delete}.
-   *
-   * @param bu1 first update in sequence
-   * @param bu2 second update in sequence
-   */
-  private static void check(final BasicUpdate bu1, final BasicUpdate bu2) {
-    // check order of location PRE, must be strictly ordered low-to-high
-    if(bu2.location < bu1.location)
-      throw Util.notExpected("Invalid order at location " + bu1.location);
-
-    if(bu2.location == bu1.location) {
-      // check invalid sequence of {@link Delete}, {@link Insert}
-      // - the inserted node would directly be deleted without this restriction
-      if(bu2 instanceof Insert || bu2 instanceof InsertAttr)
-        if(bu1 instanceof Delete)
-          throw Util.notExpected("Invalid sequence of delete, insert at location " + bu1.location);
-        else if(bu1 instanceof Replace)
-          throw Util.notExpected("Invalid sequence of replace, insert at location " + bu1.location);
-
-      // check multiple {@link Delete}, {@link Replace}
-      if(bu2.destructive() && bu1.destructive())
-        throw Util.notExpected("Multiple deletes/replaces on node " + bu1.location);
-
-      // check multiple {@link Rename}
-      if(bu2 instanceof Rename && bu1 instanceof Rename)
-        throw Util.notExpected("Multiple renames on node " + bu1.location);
-
-      // check multiple {@link UpdateValue}
-      if(bu2 instanceof UpdateValue && bu1 instanceof UpdateValue)
-        throw Util.notExpected("Multiple updates on node " + bu1.location);
-
-      /* Check invalid order of destructive/non-destructive updates to support TAU
-       *  cases like: <rename X, delete X>: node X would be deleted and then X+1 renamed,
-       *  as this shifts down to X.
-       */
-      if(bu2.destructive() && !(bu1 instanceof StructuralUpdate))
-        throw Util.notExpected("Invalid sequence of value update and destructive update at" +
-            " location " + bu1.location);
-    }
-  }
-
-  /**
-   * Checks if the second update is superfluous. An update is considered to be superfluous
-   * if it targets a position in the subtree of a to-be-removed node.
-   * @param bu1 first update in sequence
-   * @param bu2 second update in sequence
-   * @return true if second update superfluous
-   */
-  private boolean treeAwareUpdates(final BasicUpdate bu1, final BasicUpdate bu2) {
-    if(bu1.destructive()) {
-      // we determine the lowest and highest PRE values of a superfluous update
-      final int pre = bu1.location;
-      final int fol = pre + data.size(pre, data.kind(pre));
-      /* CASE 1: candidate operates on the subtree of T and appends a node to the end of
-       * the subtree (target PRE may be equal)...
-       * CASE 2: operates within subtree of T */
-      if(bu2.location <= fol && (bu2 instanceof Insert || bu2 instanceof InsertAttr) &&
-          bu2.parent >= pre && bu2.parent < fol ||
-        bu2.location < fol) {
-        return true;
-      }
-    }
-    return false;
-  }
-
-  /**
-   * Executes the updates. Resolving text node adjacency can be skipped if adjacent text
-   * nodes are not to be expected.
-   * @param mergeTexts adjacent text nodes are to be expected and must be merged
-   */
-  public void execute(final boolean mergeTexts) {
-    data.cache = true;
-    applyUpdates();
-    adjustDistances();
-    if(mergeTexts) resolveTextAdjacency();
-    data.cache = false;
-    clear();
-  }
-
-  /**
-   * Carries out structural updates.
-   */
-  public void applyUpdates() {
-    // check if previous update still in buffer
-    flush();
-    // value updates applied front-to-back, doens't matter as there are no row shifts
-    for(final BasicUpdate u : val) u.apply(data);
-    // structural updates are applied back-to-front
-    for(int i = struct.size() - 1; i >= 0; i--) struct.get(i).apply(data);
-  }
-
-  /**
-   * Adjusts distances to restore parent-child relationships that have been invalidated
-   * by structural updates.
-   *
-   * Each structural update (insert/delete) leads to a shift of higher PRE values. This
-   * invalidates parent-child relationships. Distances are only adjusted after all
-   * structural updates have been carried out to make sure each node (that has to be
-   * updated) is only touched once.
-   */
-  private void adjustDistances() {
-    // check if any distance has changed at all
-    boolean shifts = false;
-    for(final StructuralUpdate update : struct) {
-      if(update.accumulatedShifts != 0) {
-        shifts = true;
-        break;
-      }
-    }
-    if(!shifts) return;
-
-    final IntSet updatedNodes = new IntSet();
-    for(final StructuralUpdate update : struct) {
-      /* Update distance for the affected node and all following siblings of nodes
-       * on the ancestor-or-self axis. */
-      int pre = update.preOfAffectedNode + update.accumulatedShifts;
-      while(pre < data.meta.size && !updatedNodes.contains(pre)) {
-        final int kind = data.kind(pre);
-        data.dist(pre, kind, calculateNewDistance(pre, kind));
-        updatedNodes.add(pre);
-        pre += data.size(pre, kind);
-      }
-    }
-  }
-
-  /**
-   * Calculates the new distance value for the given node after updates have been applied.
-   * @param pre the new PRE value of the node after structural updates have been applied
-   * @param kind the KIND value
-   * @return new distance for the given PRE node
-   */
-  private int calculateNewDistance(final int pre, final int kind) {
-    int distanceBefore = data.dist(pre, kind);
-    final int preBefore = calculatePreValue(pre, true);
-    // document distances are not stored in table but calculated on the fly (always pre+1)
-    if(kind == Data.DOC) distanceBefore = preBefore + 1;
-    final int parentBefore = preBefore - distanceBefore;
-    final int parentAfter = calculatePreValue(parentBefore, false);
-    return pre - parentAfter;
-  }
-
-  /**
-   * Calculates the PRE value of a given node before/after updates.
-   *
-   * Finds all updates that affect the given node N. The result is than calculated based
-   * on N and the accumulated PRE value shifts introduced by these updates.
-   *
-   * If a node has been inserted at position X and this method is used to calculate the
-   * PRE value of X before updates, X is the result. As the node at position X has not
-   * existed before the insertion, its PRE value is unchanged. If in contrast the PRE
-   * value is calculated after updates, the result is X+1, as the node with the original
-   * position X has been shifted by the insertion at position X.
-   *
-   * Make sure accumulated shifts have been calculated before calling this method!
-   *
-   * @param pre PRE value
-   * @param beforeUpdates calculate PRE value before shifts/updates have been applied
-   * @return index of update, or -1
-   */
-  public int calculatePreValue(final int pre, final boolean beforeUpdates) {
-    // find update that affects the given PRE value
-    int i = find(pre, beforeUpdates);
-    // given PRE not changed by updates
-    if(i == -1) return pre;
-    // refine the search to determine accumulated shifts for the given PRE
-    i = refine(struct, i, beforeUpdates);
-    final int acm = struct.get(i).accumulatedShifts;
-    return beforeUpdates ? pre - acm : pre + acm;
-  }
-
-  /**
-   * Used to find the update that holds the accumulated shift value that is needed to
-   * recalculate the given PRE value. In a low-to-high ordered list this is the right-most
-   * update with a target PRE value smaller or equal the given PRE value, v.v.
-   *
-   * Finds the position of the update that affects the given PRE value P.
-   * If there are multiple updates whose affected PRE value equals P, the search
-   * has to be further refined as this method returns only the first match.
-   * @param pre given PRE value
-   * @param beforeUpdates compare based on PRE values before/after updates
-   * @return index of update
-   */
-  private int find(final int pre, final boolean beforeUpdates) {
-    int left = 0;
-    int right = struct.size() - 1;
-
-    while(left <= right) {
-      if(left == right) {
-        if(c(struct, left, beforeUpdates) <= pre) return left;
-        return -1;
-      }
-      if(right - left == 1) {
-        if(c(struct, right, beforeUpdates) <= pre) return right;
-        if(c(struct, left, beforeUpdates) <= pre) return left;
-        return -1;
-      }
-      final int middle = left + right >>> 1;
-      final int value = c(struct, middle, beforeUpdates);
-      if(value == pre) return middle;
-      else if(value > pre) right = middle - 1;
-      else left = middle;
-    }
-
-    // empty array
-    return -1;
-  }
-
-  /**
-   * Finds the update with the lowest index in the given list that affects the same
-   * PRE value as the update with the given index.
-   * @param updates list of updates
-   * @param index of update
-   * @param beforeUpdates find update for PRE values before updates have been applied
-   * @return update with the highest index that invalidates the distance of the given
-   * node
-   */
-  private static int refine(final List<StructuralUpdate> updates, final int index,
-      final boolean beforeUpdates) {
-    int u = index;
-    final int value = c(updates, u++, beforeUpdates);
-    final int us = updates.size();
-    while(u < us && c(updates, u, beforeUpdates) == value) u++;
-    return u - 1;
-  }
-
-  /**
-   * Recalculates the PRE value of the first node whose distance is affected by the
-   * given update.
-   * @param updates list of updates
-   * @param index index of the update
-   * @param beforeUpdates calculate PRE value before or after updates
-   * @return PRE value
-   */
-  private static int c(final List<StructuralUpdate> updates, final int index,
-      final boolean beforeUpdates) {
-    final StructuralUpdate u = updates.get(index);
-    return u.preOfAffectedNode + (beforeUpdates ? u.accumulatedShifts : 0);
-  }
-
-  /**
-   * Resolves unwanted text node adjacency which can result from structural changes in
-   * the database. Adjacent text nodes are two text nodes A and B, where
-   * PRE(B)=PRE(A)+1 and PARENT(A)=PARENT(B).
-   */
-  private void resolveTextAdjacency() {
-    // Text node merges are also gathered on a separate list to leverage optimizations.
-    final List<Delete> deletes = new LinkedList<>();
-
-    // keep track of the visited locations to avoid superfluous checks
-    int smallestVisited = Integer.MAX_VALUE;
-    // Text nodes have to be merged from the highest to the lowest pre value
-    for(int i = struct.size() - 1; i >= 0; i--) {
-      final StructuralUpdate u = struct.get(i);
-      final DataClip insseq = u.getInsertionData();
-      // calculate the new location of the update, here we have to check for adjacency
-      final int newLocation = u.location + u.accumulatedShifts - u.shifts;
-      final int beforeNewLocation = newLocation - 1;
-      // check surroundings of this location for adjacent text nodes depending on the
-      // kind of update, first the one with higher PRE values (due to shifts!)
-      // ... for insert/replace ...
-      if(insseq != null) {
-        // calculate the current following node
-        final int followingNode = newLocation + insseq.size();
-        final int beforeFollowingNode = followingNode - 1;
-        // check the nodes at the end of/after the insertion sequence
-        if(beforeFollowingNode < smallestVisited) {
-          final Delete del = mergeTextNodes(beforeFollowingNode);
-          if(del != null) deletes.add(0, del);
-          smallestVisited = beforeFollowingNode;
-        }
-      }
-      // check nodes for delete and for insert before the updated location
-      if(beforeNewLocation < smallestVisited) {
-        final Delete del = mergeTextNodes(beforeNewLocation);
-        if(del != null) deletes.add(0, del);
-        smallestVisited = beforeNewLocation;
-      }
-    }
-
-    final AtomicUpdateCache auc = new AtomicUpdateCache(data);
-    for(final Delete delete : deletes) auc.considerAtomic(delete, true);
-    deletes.clear();
-    auc.applyUpdates();
-    auc.adjustDistances();
-    auc.clear();
-  }
-
-  /**
-   * Returns atomic text node merging operations if necessary for the given node PRE and
-   * its right neighbor PRE+1.
-   * @param pre node PRE value
-   * @return list of text merging operations
-   */
-  private Delete mergeTextNodes(final int pre) {
-    final int s = data.meta.size;
-    final int b = pre + 1;
-    // don't leave table
-    if(pre >= s || b >= s || pre < 0 || b < 0) return null;
-    // only merge texts
-    if(data.kind(pre) != Data.TEXT || data.kind(b) != Data.TEXT) return null;
-    // only merge neighboring texts
-    if(data.parent(pre, Data.TEXT) != data.parent(b, Data.TEXT)) return null;
-
-    // apply text node updates on the fly and throw them away
-    UpdateValue.getInstance(data, pre, Token.concat(data.text(pre, true),
-        data.text(b, true))).
-      apply(data);
-    // deletes must be cached to add them front-to-back to atomic update list
-    return Delete.getInstance(data, b);
-  }
-}
\ No newline at end of file
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/data/atomic/BasicUpdate.java basex-8.2.3/basex-core/src/main/java/org/basex/data/atomic/BasicUpdate.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/data/atomic/BasicUpdate.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/data/atomic/BasicUpdate.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,70 +0,0 @@
-package org.basex.data.atomic;
-
-import org.basex.data.*;
-
-/**
- * Abstract atomic update.
- * Atomic updates can only be initialized via {@link AtomicUpdateCache}.
- *
- * @author BaseX Team 2005-15, BSD License
- * @author Lukas Kircher
- */
-public abstract class BasicUpdate {
-  /** PRE value of the target location. */
-  final int location;
-  /** Parent PRE of nodes to insert. */
-  final int parent;
-
-  /**
-   * Constructor.
-   * @param location target node location PRE
-   * @param parent parent node PRE value
-   */
-  BasicUpdate(final int location, final int parent) {
-    this.location = location;
-    this.parent = parent;
-  }
-
-  /**
-   * Getter for accumulated shifts.
-   * @return accumulated shifts, or zero if non-structural update.
-   */
-  int accumulatedShifts() {
-    return 0;
-  }
-
-  /**
-   * Applies the update to the given data instance.
-   * @param data data instance on which to execute the update
-   */
-  abstract void apply(final Data data);
-
-  /**
-   * Returns the data to be inserted (for inserts,...).
-   * @return Insertion sequence data instance
-   */
-  abstract DataClip getInsertionData();
-
-  /**
-   * Returns whether this updates destroys the target nodes identity. Used to determine
-   * superfluous operations on the subtree of the target.
-   * @return {@code true} if target node identity destroyed
-   */
-  abstract boolean destructive();
-
-  /**
-   * Merges the given update and this update if possible.
-   * @param data data reference
-   * @param bu update to merge with
-   * @return merged atomic update or null if merge not possible
-   */
-  @SuppressWarnings("unused")
-  public BasicUpdate merge(final Data data, final BasicUpdate bu) {
-    return null;
-  }
-
-  @Override
-  public String toString() {
-    return "L" + location;
-  }
-}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/data/atomic/DataClip.java basex-8.2.3/basex-core/src/main/java/org/basex/data/atomic/DataClip.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/data/atomic/DataClip.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/data/atomic/DataClip.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,52 +0,0 @@
-package org.basex.data.atomic;
-
-import org.basex.data.*;
-
-/**
- * Data container with start and end offset. Used mostly to save memory with insertion
- * sequence caching (only one {@link Data} instance).
- *
- * Arbitrary trees can be stored in this clip. To distinguish between two insertion
- * sequences, the root node of each sequence points to the parent PRE==-1.
- *
- * @author BaseX Team 2005-15, BSD License
- * @author Christian Gruen
- */
-public final class DataClip {
-  /** Data reference. */
-  public final Data data;
-  /** Start value. */
-  public final int start;
-  /** End value (+1). */
-  public final int end;
-  /** Number of contained fragments. */
-  public int fragments;
-
-  /**
-   * Constructor.
-   * @param data data reference
-   */
-  public DataClip(final Data data) {
-    this(data, 0, data.meta.size);
-  }
-
-  /**
-   * Constructor.
-   * @param data data reference
-   * @param start start
-   * @param end end
-   */
-  public DataClip(final Data data, final int start, final int end) {
-    this.data = data;
-    this.start = start;
-    this.end = end;
-  }
-
-  /**
-   * Returns the box size.
-   * @return size
-   */
-  public int size() {
-    return end - start;
-  }
-}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/data/atomic/Delete.java basex-8.2.3/basex-core/src/main/java/org/basex/data/atomic/Delete.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/data/atomic/Delete.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/data/atomic/Delete.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,67 +0,0 @@
-package org.basex.data.atomic;
-
-import org.basex.data.*;
-
-/**
- * Atomic update operation that deletes a node.
- *
- * @author BaseX Team 2005-15, BSD License
- * @author Lukas Kircher
- */
-final class Delete extends StructuralUpdate {
-  /**
-   * Constructor.
-   * @param location target node location PRE
-   * @param shifts PRE value shifts introduced by update
-   * @param acc accumulated shifts
-   * @param first PRE value of the first node which distance has to be updated
-   * @param parent parent
-   */
-  private Delete(final int location, final int shifts, final int acc, final int first,
-      final int parent) {
-    super(location, shifts, acc, first, parent);
-  }
-
-  /**
-   * Factory.
-   * @param data data reference
-   * @param pre location pre value
-   * @return atomic delete
-   */
-  static Delete getInstance(final Data data, final int pre) {
-    final int k = data.kind(pre);
-    final int s = data.size(pre, k);
-    return new Delete(pre, -s, -s, pre + s, data.parent(pre, k));
-  }
-
-  @Override
-  void apply(final Data data) {
-    data.delete(location);
-  }
-
-  @Override
-  DataClip getInsertionData() {
-    return null;
-  }
-
-  @Override
-  boolean destructive() {
-    return true;
-  }
-
-  @Override
-  public String toString() {
-    return "\n Delete: " + super.toString();
-  }
-
-  @Override
-  public BasicUpdate merge(final Data data, final BasicUpdate bu) {
-    if(bu != null && parent == bu.parent && bu instanceof Insert &&
-        location - shifts == bu.location && data.kind(location) != Data.ATTR) {
-      final Insert ins = (Insert) bu;
-      return new Replace(location, shifts + ins.shifts,
-          ins.accumulatedShifts, preOfAffectedNode, ins.clip, parent);
-    }
-    return null;
-  }
-}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/data/atomic/InsertAttr.java basex-8.2.3/basex-core/src/main/java/org/basex/data/atomic/InsertAttr.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/data/atomic/InsertAttr.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/data/atomic/InsertAttr.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,61 +0,0 @@
-package org.basex.data.atomic;
-
-import org.basex.data.*;
-
-/**
- * Atomic update operation that inserts an attribute into a database.
- *
- * @author BaseX Team 2005-15, BSD License
- * @author Lukas Kircher
- */
-final class InsertAttr extends StructuralUpdate {
-  /** Insertion sequence. */
-  private final DataClip clip;
-
-  /**
-   * Constructor.
-   * @param location PRE value of the target node location
-   * @param shifts row shifts
-   * @param acc accumulated row shifts
-   * @param first PRE value of the first node which distance has to be updated
-   * @param parent parent PRE value for the inserted node
-   * @param clip insert sequence data clip
-   */
-  private InsertAttr(final int location, final int shifts, final int acc, final int first,
-      final int parent, final DataClip clip) {
-    super(location, shifts, acc, first, parent);
-    this.clip = clip;
-  }
-
-  /**
-   * Factory.
-   * @param pre target location PRE
-   * @param par parent of new attribute
-   * @param clip insertion sequence
-   * @return instance
-   */
-  static InsertAttr getInstance(final int pre, final int par, final DataClip clip) {
-    final int sh = clip.size();
-    return new InsertAttr(pre, sh, sh, pre, par, clip);
-  }
-
-  @Override
-  void apply(final Data data) {
-    data.insertAttr(location, parent, clip);
-  }
-
-  @Override
-  DataClip getInsertionData() {
-    return clip;
-  }
-
-  @Override
-  boolean destructive() {
-    return false;
-  }
-
-  @Override
-  public String toString() {
-    return "\nInsertAttr: " + super.toString();
-  }
-}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/data/atomic/Insert.java basex-8.2.3/basex-core/src/main/java/org/basex/data/atomic/Insert.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/data/atomic/Insert.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/data/atomic/Insert.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,72 +0,0 @@
-package org.basex.data.atomic;
-
-import org.basex.data.*;
-
-/**
- * Atomic insert that inserts a given insertion sequence data instance into a database.
- *
- * @author BaseX Team 2005-15, BSD License
- * @author Lukas Kircher
- */
-final class Insert extends StructuralUpdate {
-  /** Insertion sequence. */
-  final DataClip clip;
-
-  /**
-   * Constructor.
-   * @param location PRE value of the target node location
-   * @param shifts shifts
-   * @param acc accumulated shifts
-   * @param first PRE value of the first node which distance has to be updated
-   * @param parent parent PRE value for the inserted nodes
-   * @param clip insertion sequence data clip
-   */
-  private Insert(final int location, final int shifts, final int acc, final int first,
-      final int parent, final DataClip clip) {
-    super(location, shifts, acc, first, parent);
-    this.clip = clip;
-  }
-
-  /**
-   * Factory.
-   * @param pre target location PRE
-   * @param par parent of inserted node
-   * @param clip insertion sequence
-   * @return instance
-   */
-  static Insert getInstance(final int pre, final int par, final DataClip clip) {
-    final int s = clip.size();
-    return new Insert(pre, s, s, pre, par, clip);
-  }
-
-  @Override
-  void apply(final Data data) {
-    data.insert(location, parent, clip);
-  }
-
-  @Override
-  DataClip getInsertionData() {
-    return clip;
-  }
-
-  @Override
-  boolean destructive() {
-    return false;
-  }
-
-  @Override
-  public BasicUpdate merge(final Data data, final BasicUpdate bu) {
-    if(bu != null && parent == bu.parent && bu instanceof Delete && location == bu.location
-        && data.kind(bu.location) != Data.ATTR) {
-      final Delete del = (Delete) bu;
-      return new Replace(location, shifts + del.shifts,
-          del.accumulatedShifts, del.preOfAffectedNode, clip, parent);
-    }
-    return null;
-  }
-
-  @Override
-  public String toString() {
-    return "\n Insert: " + super.toString();
-  }
-}
\ No newline at end of file
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/data/atomic/Rename.java basex-8.2.3/basex-core/src/main/java/org/basex/data/atomic/Rename.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/data/atomic/Rename.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/data/atomic/Rename.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,68 +0,0 @@
-package org.basex.data.atomic;
-
-import org.basex.data.*;
-import org.basex.util.*;
-
-/**
- * Atomic update operation that renames a node.
- *
- * @author BaseX Team 2005-15, BSD License
- * @author Lukas Kircher
- */
-final class Rename extends BasicUpdate {
-  /** Kind of updated node. */
-  private final int kind;
-  /** The new name of the node. */
-  private final byte[] name;
-  /** Name URI. */
-  private final byte[] uri;
-
-  /**
-   * Constructor.
-   * @param location PRE value of target node location
-   * @param kind target node kind
-   * @param name new name for the target node
-   * @param uri new name uri for the target node
-   * @param parent parent node PRE
-   */
-  private Rename(final int location, final int kind, final byte[] name, final byte[] uri,
-      final int parent) {
-    super(location, parent);
-    if(name.length == 0) throw Util.notExpected("New name must not be empty.");
-    this.kind = kind;
-    this.name = name;
-    this.uri = uri;
-  }
-
-  /**
-   * Factory.
-   * @param data data reference
-   * @param pre target node PRE
-   * @param name new name
-   * @param uri new uri
-   * @return instance
-   */
-  static Rename getInstance(final Data data, final int pre, final byte[] name, final byte[] uri) {
-    return new Rename(pre, data.kind(pre), name, uri, data.parent(pre, data.kind(pre)));
-  }
-
-  @Override
-  void apply(final Data data) {
-    data.update(location, kind, name, uri);
-  }
-
-  @Override
-  DataClip getInsertionData() {
-    throw Util.notExpected("No insertion sequence needed for atomic rename operation.");
-  }
-
-  @Override
-  boolean destructive() {
-    return false;
-  }
-
-  @Override
-  public String toString() {
-    return "\n Rename: " + super.toString();
-  }
-}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/data/atomic/Replace.java basex-8.2.3/basex-core/src/main/java/org/basex/data/atomic/Replace.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/data/atomic/Replace.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/data/atomic/Replace.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,150 +0,0 @@
-package org.basex.data.atomic;
-
-import static org.basex.util.Token.*;
-
-import java.util.*;
-
-import org.basex.data.*;
-
-/**
- * Replaces a node in the database with an insertion sequence.
- *
- * @author BaseX Team 2005-15, BSD License
- * @author Lukas Kircher
- */
-final class Replace extends StructuralUpdate {
-  /** Insertion sequence. */
-  private final DataClip clip;
-
-  /**
-   * Constructor.
-   * @param location PRE value of the target node location
-   * @param clip insertion sequence data clip
-   * @param shifts PRE value shifts introduced by update
-   * @param acc accumulated shifts
-   * @param first PRE value of the first node which distance has to be updated
-   * @param parent parent node PRE
-   */
-  Replace(final int location, final int shifts, final int acc, final int first, final DataClip clip,
-      final int parent) {
-    super(location, shifts, acc, first, parent);
-    this.clip = clip;
-  }
-
-  /**
-   * Factory.
-   * @param data data reference
-   * @param pre target node PRE
-   * @param clip insertion sequence
-   * @return instance
-   */
-  static Replace getInstance(final Data data, final int pre, final DataClip clip) {
-    final int kind = data.kind(pre);
-    final int par = data.parent(pre, kind);
-    final int oldsize = data.size(pre, kind);
-    final int newsize = clip.size();
-    final int sh = newsize - oldsize;
-    return new Replace(pre, sh, sh, pre + oldsize, clip, par);
-  }
-
-  @Override
-  void apply(final Data data) {
-    // [LK] replace optimizations only work without namespaces..
-    if(data.nspaces.size() == 0 && clip.data.nspaces.size() == 0) {
-      // Lazy Replace: rewrite to value updates if structure has not changed
-      if(lazyReplace(data)) return;
-      // Rapid Replace: in-place update, overwrite existing table entries
-      data.replace(location, clip);
-    } else {
-      // fallback: delete old entries, add new ones
-      final int kind = data.kind(location);
-      final int par = data.parent(location, kind);
-      // delete first - otherwise insert must be at location+1
-      data.delete(location);
-      if(kind == Data.ATTR) {
-        data.insertAttr(location, par, clip);
-      } else {
-        data.insert(location, par, clip);
-      }
-    }
-  }
-
-  /**
-   * Lazy Replace implementation. Checks if the replace operation can be substituted with
-   * cheaper value updates. If structural changes have to be made no substitution takes place.
-   * @param data destination data reference
-   * @return true if substitution successful
-   */
-  private boolean lazyReplace(final Data data) {
-    final Data src = clip.data;
-    final int srcSize = clip.size();
-    // check for equal subtree size
-    if(srcSize != data.size(location, data.kind(location))) return false;
-
-    final List<BasicUpdate> valueUpdates = new ArrayList<>();
-    for(int c = 0; c < srcSize; c++) {
-      final int s = clip.start + c;
-      final int t = location + c;
-      final int sk = src.kind(s);
-      final int tk = data.kind(t);
-
-      if(sk != tk)
-        return false;
-      // distance can differ for first two tuples
-      if(c > 0 && src.dist(s, sk) != data.dist(t, tk))
-        return false;
-      // check texts, comments and documents
-      if(sk == Data.TEXT || sk == Data.COMM || sk == Data.DOC) {
-        final byte[] srcText = src.text(s, true);
-        if(!eq(data.text(t, true), srcText))
-          valueUpdates.add(UpdateValue.getInstance(data, t, srcText));
-      } else {
-        // check elements, attributes and processing instructions
-        final byte[] srcName = src.name(s, sk);
-        final byte[] trgName = data.name(t, tk);
-        if(!eq(srcName, trgName)) valueUpdates.add(Rename.getInstance(data, t, srcName, EMPTY));
-        switch(sk) {
-          case Data.ELEM:
-            // check size of elements
-            if(src.attSize(s, sk) != data.attSize(t, tk) || src.size(s, sk) != data.size(t, tk))
-              return false;
-            break;
-          case Data.ATTR:
-            // check attribute values
-            final byte[] av = src.text(s, false);
-            if(!eq(data.text(t, false), av))
-              valueUpdates.add(UpdateValue.getInstance(data, t, av));
-            break;
-          case Data.PI:
-            // check processing instruction value
-            final byte[] srcText = src.text(s, true);
-            final byte[] trgText = data.text(t, true);
-            final int i = indexOf(srcText, ' ');
-            final byte[] pv = i == -1 ? EMPTY : substring(srcText, i + 1);
-            if(!eq(pv, indexOf(trgText, ' ') == -1 ? EMPTY :
-              substring(trgText, i + 1))) {
-              valueUpdates.add(UpdateValue.getInstance(data, t, pv));
-            }
-            break;
-        }
-      }
-    }
-    for(final BasicUpdate bu : valueUpdates) bu.apply(data);
-    return true;
-  }
-
-  @Override
-  DataClip getInsertionData() {
-    return clip;
-  }
-
-  @Override
-  boolean destructive() {
-    return true;
-  }
-
-  @Override
-  public String toString() {
-    return "\nReplace: " + super.toString();
-  }
-}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/data/atomic/StructuralUpdate.java basex-8.2.3/basex-core/src/main/java/org/basex/data/atomic/StructuralUpdate.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/data/atomic/StructuralUpdate.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/data/atomic/StructuralUpdate.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,48 +0,0 @@
-package org.basex.data.atomic;
-
-/**
- * Base class for structural updates that add to/remove from the table and introduce shifts.
- * @author BaseX Team 2005-15, BSD License
- * @author Lukas Kircher
- */
-abstract class StructuralUpdate extends BasicUpdate {
-  /** PRE value shifts introduced by this atomic update due to structural changes. */
-  final int shifts;
-  /** PRE value of the first node for which the distance must be updated due to PRE value
-   * shifts introduced by this update. */
-  final int preOfAffectedNode;
-  /** Total/accumulated number of shifts introduced by all updates on the list up to this
-   * update (inclusive). The number of total shifts is used to calculate PRE values
-   * before/after updates. */
-  int accumulatedShifts;
-
-  /**
-   * Constructor.
-   * @param location target node location PRE
-   * @param shifts PRE value shifts introduced by update
-   * @param acc accumulated shifts
-   * @param first PRE value of the first node the distance of which has to be updated
-   * @param parent parent node
-   */
-  StructuralUpdate(final int location, final int shifts, final int acc, final int first,
-      final int parent) {
-    super(location, parent);
-    this.shifts = shifts;
-    accumulatedShifts = acc;
-    preOfAffectedNode = first;
-  }
-
-  @Override
-  int accumulatedShifts() {
-    return accumulatedShifts;
-  }
-
-  @Override
-  public String toString() {
-    return "L" + location +
-        " PAR" + parent +
-        " SHF" + shifts +
-        " ASHF" + accumulatedShifts +
-        " AFF" + preOfAffectedNode;
-  }
-}
\ No newline at end of file
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/data/atomic/UpdateValue.java basex-8.2.3/basex-core/src/main/java/org/basex/data/atomic/UpdateValue.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/data/atomic/UpdateValue.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/data/atomic/UpdateValue.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,62 +0,0 @@
-package org.basex.data.atomic;
-
-import org.basex.data.*;
-import org.basex.util.*;
-
-/**
- * Atomic update operation that replaces the value of a single text, comment, pi or
- * attribute node.
- *
- * @author BaseX Team 2005-15, BSD License
- * @author Lukas Kircher
- */
-final class UpdateValue extends BasicUpdate {
-  /** Target node kind. */
-  private final int kind;
-  /** New value for target node. */
-  private final byte[] value;
-
-  /**
-   * Constructor.
-   * @param location PRE value of the target node location
-   * @param kind node kind of the target node
-   * @param value new value which is assigned to the target node
-   * @param parent parent of updated node
-   */
-  private UpdateValue(final int location, final int kind, final byte[] value, final int parent) {
-    super(location, parent);
-    this.kind = kind;
-    this.value = value;
-  }
-
-  /**
-   * Factory.
-   * @param data data reference
-   * @param pre PRE value of the target node location
-   * @param value new value which is assigned to the target node
-   * @return new instance
-   */
-  static UpdateValue getInstance(final Data data, final int pre, final byte[] value) {
-    return new UpdateValue(pre, data.kind(pre), value, data.parent(pre, data.kind(pre)));
-  }
-
-  @Override
-  void apply(final Data data) {
-    data.update(location, kind, value);
-  }
-
-  @Override
-  DataClip getInsertionData() {
-    throw Util.notExpected("No insertion sequence needed for atomic value update operation.");
-  }
-
-  @Override
-  boolean destructive() {
-    return false;
-  }
-
-  @Override
-  public String toString() {
-    return "\nUpdateValue: " + super.toString();
-  }
-}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/data/DataClip.java basex-8.2.3/basex-core/src/main/java/org/basex/data/DataClip.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/data/DataClip.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/data/DataClip.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,62 @@
+package org.basex.data;
+
+/**
+ * Data container with start and end offset. Used mostly to save memory with insertion
+ * sequence caching (only one {@link Data} instance).
+ *
+ * Arbitrary trees can be stored in this clip. To distinguish between two insertion
+ * sequences, the root node of each sequence points to the virtual parent pre value -1.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Christian Gruen
+ */
+public final class DataClip {
+  /** Data reference. */
+  public final Data data;
+  /** Start value. */
+  public final int start;
+  /** End value (+1). */
+  public final int end;
+  /** Number of contained fragments. */
+  public final int fragments;
+
+  /**
+   * Constructor.
+   * @param data data reference
+   */
+  public DataClip(final Data data) {
+    this(data, 0, data.meta.size);
+  }
+
+  /**
+   * Constructor.
+   * @param data data reference
+   * @param start start
+   * @param end end
+   */
+  public DataClip(final Data data, final int start, final int end) {
+    this(data, start, end, 1);
+  }
+
+  /**
+   * Constructor.
+   * @param data data reference
+   * @param start start
+   * @param end end
+   * @param fragments number of fragments
+   */
+  public DataClip(final Data data, final int start, final int end, final int fragments) {
+    this.data = data;
+    this.start = start;
+    this.end = end;
+    this.fragments = fragments;
+  }
+
+  /**
+   * Returns the box size.
+   * @return size
+   */
+  public int size() {
+    return end - start;
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/data/Data.java basex-8.2.3/basex-core/src/main/java/org/basex/data/Data.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/data/Data.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/data/Data.java	2015-07-14 10:54:40.000000000 +0000
@@ -4,20 +4,19 @@
 
 import java.io.*;
 import java.util.*;
-import java.util.List;
 
 import org.basex.core.*;
 import org.basex.core.cmd.*;
-import org.basex.data.atomic.*;
 import org.basex.index.*;
 import org.basex.index.name.*;
 import org.basex.index.path.*;
 import org.basex.index.query.*;
 import org.basex.index.resource.*;
+import org.basex.index.value.*;
 import org.basex.io.*;
 import org.basex.io.random.*;
+import org.basex.query.*;
 import org.basex.util.*;
-import org.basex.util.hash.*;
 import org.basex.util.list.*;
 
 /**
@@ -96,11 +95,11 @@
   /** Path summary index. */
   public PathSummary paths;
   /** Text index. */
-  public Index textIndex;
+  public ValueIndex textIndex;
   /** Attribute value index. */
-  public Index attrIndex;
+  public ValueIndex attrIndex;
   /** Full-text index instance. */
-  public Index ftxtIndex;
+  public ValueIndex ftxtIndex;
 
   /** Table access file. */
   TableAccess table;
@@ -373,16 +372,16 @@
   public final byte[] attValue(final int att, final int pre) {
     final int a = pre + attSize(pre, kind(pre));
     int p = pre;
-    while(++p != a) if(name(p) == att) return text(p, false);
+    while(++p != a) if(nameId(p) == att) return text(p, false);
     return null;
   }
 
   /**
-   * Returns a reference to the name of an element, attribute or processing instruction.
+   * Returns the id of the name of an element, attribute or processing instruction.
    * @param pre pre value
-   * @return token reference
+   * @return name id
    */
-  public final int name(final int pre) {
+  public final int nameId(final int pre) {
     return table.read2(pre, 1) & 0x7FFF;
   }
 
@@ -398,18 +397,38 @@
       final int i = indexOf(name, ' ');
       return i == -1 ? name : substring(name, 0, i);
     }
-    return (kind == ELEM ? elemNames : attrNames).key(name(pre));
+    return (kind == ELEM ? elemNames : attrNames).key(nameId(pre));
   }
 
   /**
-   * Returns a reference to the namespace of the addressed element or attribute.
+   * Returns the id of the namespace uri of the addressed element or attribute.
    * @param pre pre value
    * @param kind node kind
-   * @return namespace URI
+   * @return id of the namespace uri
    */
-  public final int uri(final int pre, final int kind) {
-    return kind == ELEM || kind == ATTR ?
-        table.read1(pre, kind == ELEM ? 3 : 11) & 0xFF : 0;
+  public final int uriId(final int pre, final int kind) {
+    return kind == ELEM || kind == ATTR ? table.read1(pre, kind == ELEM ? 3 : 11) & 0xFF : 0;
+  }
+
+  /**
+   * Returns the name and namespace uri of the addressed element or attribute.
+   * @param pre pre value
+   * @param kind node kind
+   * @return array with name and namespace uri
+   */
+  public final byte[][] qname(final int pre, final int kind) {
+    final byte[] name = name(pre, kind);
+    byte[] uri = null;
+    final boolean hasPrefix = indexOf(name, ':') != -1;
+    if(hasPrefix || !nspaces.isEmpty()) {
+      final int uriId = uriId(pre, kind);
+      if(uriId > 0) {
+        uri = nspaces.uri(uriId);
+      } else if(hasPrefix && eq(prefix(name), XML)) {
+        uri = QueryText.XML_URI;
+      }
+    }
+    return new byte[][] { name, uri == null ? EMPTY : uri };
   }
 
   /**
@@ -422,21 +441,13 @@
   }
 
   /**
-   * Returns all namespace keys and values.
+   * Returns all namespace prefixes and uris that are defined for the specified pre value.
    * Should only be called for element nodes.
    * @param pre pre value
    * @return key and value ids
    */
-  public final Atts ns(final int pre) {
-    final Atts as = new Atts();
-    if(nsFlag(pre)) {
-      final int[] nsp = nspaces.get(pre, this);
-      final int nl = nsp.length;
-      for(int n = 0; n < nl; n += 2) {
-        as.add(nspaces.prefix(nsp[n]), nspaces.uri(nsp[n + 1]));
-      }
-    }
-    return as;
+  public final Atts namespaces(final int pre) {
+    return nsFlag(pre) ? nspaces.values(pre, this) : new Atts();
   }
 
   /**
@@ -486,10 +497,10 @@
 
   /**
    * Updates (renames) the name of an element, attribute or processing instruction.
-   * @param pre pre value
-   * @param kind node kind
-   * @param name name of new element, attribute or processing instruction
-   * @param uri uri
+   * @param pre pre value of the node to be updated
+   * @param kind node kind of the updated node
+   * @param name name of the new element, attribute or processing instruction
+   * @param uri namespace uri
    */
   public final void update(final int pre, final int kind, final byte[] name, final byte[] uri) {
     meta.update();
@@ -497,179 +508,179 @@
     if(kind == PI) {
       updateText(pre, trim(concat(name, SPACE, atom(pre))), PI);
     } else {
-      // update/set namespace reference
-      final int ouri = nspaces.uri(name, pre, this);
-      final boolean ne = ouri == 0 && uri.length != 0;
-      final int npre = kind == ATTR ? parent(pre, kind) : pre;
-      final int nuri = ne ? nspaces.add(npre, npre, prefix(name), uri, this) :
-        ouri != 0 && eq(nspaces.uri(ouri), uri) ? ouri : 0;
-
-      // write namespace uri reference
-      table.write1(pre, kind == ELEM ? 3 : 11, nuri);
-      // write name reference
-      table.write2(pre, 1, (nsFlag(pre) ? 1 << 15 : 0) |
-        (kind == ELEM ? elemNames : attrNames).index(name, null, false));
-      // write namespace flag
-      table.write2(npre, 1, (ne || nsFlag(npre) ? 1 << 15 : 0) | name(npre));
+      // check if namespace has changed
+      final byte[] prefix = prefix(name);
+      final int oldUriId = nspaces.uriIdForPrefix(prefix, pre, this);
+      final boolean nsFlag = oldUriId == 0 && uri.length != 0 && !eq(prefix, XML);
+      final int nsPre = kind == ATTR ? parent(pre, kind) : pre;
+      final int uriId = nsFlag ? nspaces.add(nsPre, prefix, uri, this) :
+        oldUriId != 0 && eq(nspaces.uri(oldUriId), uri) ? oldUriId : 0;
+
+      // write ids of namespace uri and name, and namespace flag
+      if(kind == ATTR) {
+        table.write1(pre, 11, uriId);
+        table.write2(pre, 1, attrNames.index(name, null, false));
+        if(nsFlag) table.write2(nsPre, 1, 1 << 15 | nameId(nsPre));
+      } else {
+        table.write1(pre, 3, uriId);
+        final int nameId = elemNames.index(name, null, false);
+        table.write2(nsPre, 1, (nsFlag || nsFlag(nsPre) ? 1 << 15 : 0) | nameId);
+      }
     }
   }
 
   /**
-   * Updates (replaces) the value of a single document, text, comment, pi or
-   * attribute node.
-   * @param pre pre value to be replaced
+   * Updates (replaces) the value of a single text, comment, pi, attribute or document node.
+   * @param pre pre value of the node to be updated
    * @param kind node kind
-   * @param value value to be updated (element name, text, comment, pi, document)
+   * @param value value to be updated (text, comment, pi, attribute, document name)
    */
   public final void update(final int pre, final int kind, final byte[] value) {
-    final byte[] v = kind == PI ? trim(concat(name(pre, kind), SPACE, value)) : value;
-    if(eq(v, text(pre, kind != ATTR))) return;
+    final byte[] val = kind == PI ? trim(concat(name(pre, kind), SPACE, value)) : value;
+    if(eq(val, text(pre, kind != ATTR))) return;
 
     meta.update();
-    updateText(pre, v, kind);
+    updateText(pre, val, kind);
     if(kind == DOC) resources.rename(pre, value);
   }
 
   /**
    * Rapid Replace implementation. Replaces parts of the database with the specified data instance.
-   * @param tpre pre value of target node to be replaced
+   * @param pre pre value of the node to be replaced
    * @param source clip with source data
    */
-  public final void replace(final int tpre, final DataClip source) {
+  public final void replace(final int pre, final DataClip source) {
     meta.update();
 
-    final int size = source.size();
-    final Data data = source.data;
-
-    final int tkind = kind(tpre);
-    final int tsize = size(tpre, tkind);
-    final int tpar = parent(tpre, tkind);
-    final int diff = size - tsize;
-    buffer(size);
-    resources.replace(tpre, tsize, source);
+    final int sCount = source.size();
+    final int tKind = kind(pre);
+    final int tSize = size(pre, tKind);
+    final int tPar = parent(pre, tKind);
+    bufferSize(sCount);
+    resources.replace(pre, tSize, source);
 
+    // initialize update of updatable index structures
     if(meta.updindex) {
-      // update index
-      indexDelete(tpre, tsize);
+      indexDelete(pre, tSize);
       indexBegin();
     }
 
+    final Data sData = source.data;
     int sTopPre = source.start;
-    for(int spre = sTopPre; spre < source.end; ++spre) {
-      final int kind = data.kind(spre);
-      // size and parent value of source node
-      final int ssize = data.size(spre, kind);
-      final int spar = data.parent(spre, kind);
-      final int pre = tpre + spre - source.start;
+    for(int sPre = source.start; sPre < source.end; ++sPre) {
+      // properties of the source node
+      final int sKind = sData.kind(sPre);
+      final int sSize = sData.size(sPre, sKind);
+      final int sPar = sData.parent(sPre, sKind);
+      final int cPre = pre + sPre - source.start;
 
       // calculate new distance value
-      final int dist;
-      if(spre == sTopPre) {
+      final int cDist;
+      if(sPre == sTopPre) {
         // handle top level entry: calculate distance based on target database
-        dist = pre - tpar;
+        cDist = cPre - tPar;
         // calculate pre value of next top level entry
-        sTopPre += ssize;
+        sTopPre += sSize;
       } else {
-        dist = spre - spar;
+        cDist = sPre - sPar;
       }
 
-      switch(kind) {
+      switch(sKind) {
         case DOC:
           // add document
-          doc(pre, ssize, data.text(spre, true));
+          doc(cPre, sSize, sData.text(sPre, true));
           ++meta.ndocs;
           break;
         case ELEM:
           // add element
-          final byte[] en = data.name(spre, kind);
-          elem(dist, elemNames.index(en, null, false), data.attSize(spre, kind), ssize,
-              nspaces.uri(en, true), false);
+          final byte[] en = sData.name(sPre, sKind);
+          elem(cDist, elemNames.index(en, null, false), sData.attSize(sPre, sKind), sSize,
+              nspaces.uriIdForPrefix(prefix(en), true), false);
           break;
         case TEXT:
         case COMM:
         case PI:
           // add text
-          text(pre, dist, data.text(spre, true), kind);
+          text(cPre, cDist, sData.text(sPre, true), sKind);
           break;
         case ATTR:
           // add attribute
-          final byte[] an = data.name(spre, kind);
-          attr(pre, dist, attrNames.index(an, null, false), data.text(spre, false),
-              nspaces.uri(an, false), false);
+          final byte[] an = sData.name(sPre, sKind);
+          attr(cPre, cDist, attrNames.index(an, null, false), sData.text(sPre, false),
+              nspaces.uriIdForPrefix(prefix(an), false));
           break;
       }
     }
 
+    // update ID -> PRE map and index structures
     if(meta.updindex) {
+      idmap.delete(pre, id(pre), -tSize);
+      idmap.insert(pre, meta.lastid - sCount + 1, sCount);
       indexAdd();
-      // update ID -> PRE map:
-      idmap.delete(tpre, id(tpre), -tsize);
-      idmap.insert(tpre, meta.lastid - size + 1, size);
     }
 
-    // update table:
-    table.replace(tpre, buffer(), tsize);
-    buffer(1);
-
-    // no distance/size update if the two subtrees are of equal size
-    if(diff == 0) return;
-
-    // increase/decrease size of ancestors, adjust distances of siblings
-    int p = tpar;
-    while(p >= 0) {
-      final int k = kind(p);
-      size(p, k, size(p, k) + diff);
-      p = parent(p, k);
+    // replace table entries, reset buffer size
+    table.replace(pre, buffer(), tSize);
+    bufferSize(1);
+
+    // if necessary, increase/decrease size of ancestors and adjust distances of siblings
+    final int diff = sCount - tSize;
+    if(diff != 0) {
+      int p = tPar;
+      while(p >= 0) {
+        final int k = kind(p);
+        size(p, k, size(p, k) + diff);
+        p = parent(p, k);
+      }
+      if(!cache) updateDist(pre + sCount, diff);
     }
 
-    if(!cache) updateDist(tpre + size, diff);
-
     // adjust attribute size of parent if attributes inserted. attribute size
-    // of parent cannot be reduced via a replace expression.
-    int spre = source.start;
-    if(data.kind(spre) == ATTR) {
+    // of parent cannot be decreased via a replace expression.
+    int sPre = source.start;
+    if(sData.kind(sPre) == ATTR) {
       int d = 0;
-      while(spre < source.end && data.kind(spre++) == ATTR) d++;
-      if(d > 1) attSize(tpar, kind(tpar), d + attSize(tpar, ELEM) - 1);
+      while(sPre < source.end && sData.kind(sPre++) == ATTR) d++;
+      if(d > 1) attSize(tPar, kind(tPar), d + attSize(tPar, ELEM) - 1);
     }
   }
 
   /**
    * Deletes a node and its descendants.
-   * @param pre pre value of the node to delete
+   * @param pre pre value of the node to be deleted
    */
   public final void delete(final int pre) {
     meta.update();
 
     // delete references in document index
-    int k = kind(pre);
-    final int s = size(pre, k);
-    resources.delete(pre, s);
+    int kind = kind(pre);
+    final int size = size(pre, kind);
+    resources.delete(pre, size);
 
     // delete entries in value indexes
-    if(meta.updindex) indexDelete(pre, s);
+    if(meta.updindex) indexDelete(pre, size);
 
     /// delete text or attribute value in heap file
-    if(k != DOC && k != ELEM) delete(pre, k != ATTR);
+    if(kind != DOC && kind != ELEM) delete(pre, kind != ATTR);
 
     // reduce size of ancestors
     int par = pre;
     // check if we are an attribute (different size counters)
-    if(k == ATTR) {
+    if(kind == ATTR) {
       par = parent(par, ATTR);
       attSize(par, ELEM, attSize(par, ELEM) - 1);
       size(par, ELEM, size(par, ELEM) - 1);
-      k = kind(par);
+      kind = kind(par);
     }
 
-    // delete namespace nodes and propagate PRE value shifts (before node sizes are touched!)
-    nspaces.delete(pre, s, this);
+    // delete namespace nodes and propagate pre value shifts (before node sizes are touched!)
+    nspaces.delete(pre, size, this);
 
     // reduce size of ancestors
-    while(par > 0 && k != DOC) {
-      par = parent(par, k);
-      k = kind(par);
-      size(par, k, size(par, k) - s);
+    while(par > 0 && kind != DOC) {
+      par = parent(par, kind);
+      kind = kind(par);
+      size(par, kind, size(par, kind) - size);
     }
 
     // preserve empty root node
@@ -677,169 +688,143 @@
 
     if(meta.updindex) {
       // delete node and descendants from ID -> PRE map:
-      idmap.delete(pre, id(pre), -s);
+      idmap.delete(pre, id(pre), -size);
     }
 
     // delete node from table structure and reduce document size
-    table.delete(pre, s);
+    table.delete(pre, size);
 
-    if(!cache) updateDist(pre, -s);
+    if(!cache) updateDist(pre, -size);
   }
 
   /**
-   * Inserts attributes.
-   * @param pre pre value
-   * @param par parent of node
+   * Inserts standalone attributes (without root element).
+   * @param pre target pre value (insertion position)
+   * @param par target parent pre value of node
    * @param source clip with source data
    */
   public final void insertAttr(final int pre, final int par, final DataClip source) {
-    insert(pre, par, source);
+    // #1168/2: store one by one (otherwise, namespace declarations may be added more than once)
+    for(int s = 0; s < source.fragments; s++) {
+      final int start = source.start + s;
+      insert(pre + s, par, new DataClip(source.data, start, start + 1));
+    }
     attSize(par, ELEM, attSize(par, ELEM) + source.size());
   }
 
   /**
-   * Inserts a data instance at the specified pre value.
-   * Note that the specified data instance must differ from this instance.
-   * @param tpre target pre value
-   * @param tpar target parent pre value of node ({@code -1} if document is added)
+   * Inserts a data instance at the specified pre value. Notes:
+   * <ul>
+   *   <li> The data instance in the specified data clip must differ from this instance.</li>
+   *   <li> Attributes must be inserted via {@link #insertAttr}.</li>
+   * </ul>
+   * @param pre target pre value (insertion position)
+   * @param par target parent pre value of node ({@code -1} if document is added)
    * @param source clip with source data
    */
-  public final void insert(final int tpre, final int tpar, final DataClip source) {
+  public final void insert(final int pre, final int par, final DataClip source) {
     meta.update();
 
     // update value and document indexes
     if(meta.updindex) indexBegin();
-    resources.insert(tpre, source);
+    resources.insert(pre, source);
 
-    final int size = source.size();
-    final int buf = Math.min(size, IO.BLOCKSIZE >> IO.NODEPOWER);
     // resize buffer to cache more entries
-    buffer(buf);
-
-    // find all namespaces in scope to avoid duplicate declarations
-    final TokenMap nsScope = nspaces.scope(tpar, this);
+    final int sCount = source.size();
+    final int bSize = Math.min(sCount, IO.BLOCKSIZE >> IO.NODEPOWER);
+    bufferSize(bSize);
 
-    // loop through all entries
-    final IntList preStack = new IntList();
-    final NSNode nsRoot = nspaces.getCurrent();
-    final IntList flagPres = new IntList();
-    // track existing NSNodes - their PRE values have to be shifted after each tuple insertion
-    final List<NSNode> nsNodesShift = nspaces.getNSNodes(tpre);
+    // organize namespaces to avoid duplicate declarations
+    final NSScope nsScope = new NSScope(pre, this);
 
     // indicates if database only contains a dummy node
-    final Data data = source.data;
+    final Data sdata = source.data;
     int c = 0, sTopPre = source.start;
-    for(int spre = sTopPre; spre < source.end; ++spre, ++c) {
-      if(c != 0 && c % buf == 0) insert(tpre + c - buf);
+    for(int sPre = sTopPre; sPre < source.end; ++sPre, ++c) {
+      if(c != 0 && c % bSize == 0) insert(pre + c - bSize);
 
-      final int pre = tpre + c;
-      final int kind = data.kind(spre);
-      // size and parent value of source node
-      final int ssize = data.size(spre, kind);
-      final int spar = data.parent(spre, kind);
-
-      // calculate new distance value
-      final int dist;
-      if(spre == sTopPre) {
+      // values of source node
+      final int sKind = sdata.kind(sPre);
+      final int sSize = sdata.size(sPre, sKind);
+      final int sPar = sdata.parent(sPre, sKind);
+
+      // pre and dist value of new node
+      final int nPre = pre + c, nDist;
+      if(sPre == sTopPre) {
         // handle top level entry: calculate distance based on target database
-        dist = pre - tpar;
+        nDist = nPre - par;
         // calculate pre value of next top level entry
-        sTopPre += ssize;
+        sTopPre += sSize;
       } else {
         // handle descendant node: calculate distance based on source database
-        dist = spre - spar;
+        nDist = sPre - sPar;
       }
-
       // documents: use -1 as namespace root
-      final int nsPre = kind == DOC ? -1 : pre - dist;
-      if(c == 0) nspaces.root(nsPre, this);
-      while(!preStack.isEmpty() && preStack.peek() > nsPre) nspaces.close(preStack.pop());
+      final int nsPre = sKind == DOC ? -1 : nPre - nDist;
+      nsScope.loop(nsPre, c);
 
-      switch(kind) {
+      switch(sKind) {
         case DOC:
           // add document
-          nspaces.prepare();
-          doc(pre, ssize, data.text(spre, true));
+          nsScope.open(nPre);
+          doc(nPre, sSize, sdata.text(sPre, true));
           ++meta.ndocs;
-          preStack.push(pre);
           break;
-        case ELEM:
-          // add element
-          nspaces.prepare();
-          boolean ne = false;
-          if(data.nsFlag(spre)) {
-            final Atts at = data.ns(spre);
-            final int as = at.size();
-            for(int a = 0; a < as; a++) {
-              // see if prefix has been declared/ is part of current ns scope
-              final byte[] old = nsScope.get(at.name(a));
-              if(old == null || !eq(old, at.value(a))) {
-                nspaces.add(at.name(a), at.value(a), pre);
-                ne = true;
-              }
-            }
-          }
-          final byte[] en = data.name(spre, kind);
-          elem(dist, elemNames.index(en, null, false), data.attSize(spre, kind), ssize,
-              nspaces.uri(en, true), ne);
-          preStack.push(pre);
+        case ELEM: {
+          // add element.
+          final boolean nsFlag = nsScope.open(nPre, sdata.namespaces(sPre));
+          final byte[] name = sdata.name(sPre, sKind);
+          elem(nDist, elemNames.index(name, null, false), sdata.attSize(sPre, sKind), sSize,
+              nspaces.uriIdForPrefix(prefix(name), true), nsFlag);
           break;
+        }
         case TEXT:
         case COMM:
         case PI:
-          // add text
-          text(pre, dist, data.text(spre, true), kind);
+          // add text, comment or processing instruction
+          text(nPre, nDist, sdata.text(sPre, true), sKind);
           break;
-        case ATTR:
+        case ATTR: {
           // add attribute
-          final byte[] an = data.name(spre, kind);
-          // check if prefix already in nsScope or not
-          final byte[] attPref = prefix(an);
-          if(data.nsFlag(spre) && nsScope.get(attPref) == null) {
-            // add declaration to parent node
-            nspaces.add(nsPre, preStack.isEmpty() ? -1 : preStack.peek(), attPref,
-            data.nspaces.uri(data.uri(spre, kind)), this);
-            // save pre value to set ns flag later for this node. can't be done
-            // here as direct table access would interfere with the buffer
-            flagPres.add(nsPre);
+          final byte[] name = sdata.name(sPre, sKind);
+          int uriId = sdata.uriId(sPre, sKind);
+          // extend namespace scope and write namespace flag if attribute has a new namespaces
+          if(uriId != 0) {
+            final byte[] prefix = prefix(name), uri = sdata.nspaces.uri(uriId);
+            uriId = nspaces.uriIdForPrefix(prefix, false);
+            if(uriId == 0 && !Token.eq(prefix, Token.XML)) {
+              uriId = nspaces.add(nsPre, prefix, uri, this);
+              table.write2(nsPre, 1, 1 << 15 | nameId(nsPre));
+            }
           }
-          attr(pre, dist, attrNames.index(an, null, false), data.text(spre, false),
-              nspaces.uri(an, false), false);
-          break;
+          attr(nPre, nDist, attrNames.index(name, null, false), sdata.text(sPre, false), uriId);
+        }
       }
-      // propagate PRE value shifts to keep namespace structure valid
-      Namespaces.incrementPre(nsNodesShift, 1);
+      nsScope.shift(1);
     }
     // finalize and update namespace structure
-    while(!preStack.isEmpty()) nspaces.close(preStack.pop());
-    nspaces.setCurrent(nsRoot);
+    nsScope.close();
 
-    if(bp != 0) insert(tpre + c - 1 - (c - 1) % buf);
-    // reset buffer to old size
-    buffer(1);
-
-    // set namespace flags
-    final int fs = flagPres.size();
-    for(int f = 0; f < fs; f++) {
-      final int fl = flagPres.get(f);
-      table.write2(fl, 1, name(fl) | 1 << 15);
-    }
+    // write final entries and reset buffer
+    if(bp != 0) insert(pre + c - 1 - (c - 1) % bSize);
+    bufferSize(1);
 
     // increase size of ancestors
-    int p = tpar;
-    while(p >= 0) {
-      final int k = kind(p);
-      size(p, k, size(p, k) + size);
-      p = parent(p, k);
+    int cPre = par;
+    while(cPre >= 0) {
+      final int cKind = kind(cPre);
+      size(cPre, cKind, size(cPre, cKind) + sCount);
+      cPre = parent(cPre, cKind);
     }
 
+    // add entries to the ID -> PRE mapping
     if(meta.updindex) {
-      // add the entries to the ID -> PRE mapping:
-      idmap.insert(tpre, id(tpre), size);
+      idmap.insert(pre, id(pre), sCount);
       indexAdd();
     }
 
-    if(!cache) updateDist(tpre + size, size);
+    // finally, update distances
+    if(!cache) updateDist(pre + sCount, sCount);
   }
 
   /**
@@ -911,15 +896,14 @@
    * Sets the namespace flag.
    * Should be only called for element nodes.
    * @param pre pre value
-   * @param ne namespace flag
+   * @param nsFlag namespace flag
    */
-  public final void nsFlag(final int pre, final boolean ne) {
-    table.write1(pre, 1, table.read1(pre, 1) & 0x7F | (ne ? 0x80 : 0));
+  public final void nsFlag(final int pre, final boolean nsFlag) {
+    table.write1(pre, 1, table.read1(pre, 1) & 0x7F | (nsFlag ? 0x80 : 0));
   }
 
   /**
-   * Inserts the internal buffer to the storage
-   * without updating the table structure.
+   * Inserts the internal buffer to the storage without updating the table structure.
    * @param pre insert position
    */
   public final void insert(final int pre) {
@@ -944,7 +928,7 @@
    * Sets the update buffer to a new size.
    * @param size number of table entries
    */
-  private void buffer(final int size) {
+  private void bufferSize(final int size) {
     final int bs = size << IO.NODEPOWER;
     if(b.length != bs) b = new byte[bs];
   }
@@ -967,20 +951,20 @@
   /**
    * Adds an element entry to the internal update buffer.
    * @param dist parent distance
-   * @param name element name index
+   * @param nameId id of element name
    * @param asize number of attributes
    * @param size node size
-   * @param uri namespace uri reference
-   * @param ne namespace flag
+   * @param uriId id of namespace uri
+   * @param nsFlag namespace flag
    */
-  public final void elem(final int dist, final int name, final int asize, final int size,
-      final int uri, final boolean ne) {
+  public final void elem(final int dist, final int nameId, final int asize, final int size,
+      final int uriId, final boolean nsFlag) {
 
     // build and insert new entry
     final int i = newID();
-    final int n = ne ? 1 << 7 : 0;
+    final int n = nsFlag ? 1 << 7 : 0;
     s(Math.min(IO.MAXATTS, asize) << 3 | ELEM);
-    s(n | (byte) (name >> 8)); s(name); s(uri);
+    s(n | (byte) (nameId >> 8)); s(nameId); s(uriId);
     s(dist >> 24); s(dist >> 16); s(dist >> 8); s(dist);
     s(size >> 24); s(size >> 16); s(size >> 8); s(size);
     s(i >> 24); s(i >> 16); s(i >> 8); s(i);
@@ -1007,22 +991,20 @@
    * Adds an attribute entry to the internal update buffer.
    * @param pre pre value
    * @param dist parent distance
-   * @param name attribute name
+   * @param nameId id of attribute name
    * @param value attribute value
-   * @param uri namespace uri reference
-   * @param ne namespace flag (only {@code true} if this is a stand-alone attribute)
+   * @param uriId id of namespace uri
    */
-  public final void attr(final int pre, final int dist, final int name, final byte[] value,
-      final int uri, final boolean ne) {
+  public final void attr(final int pre, final int dist, final int nameId, final byte[] value,
+      final int uriId) {
 
     // add attribute to text storage
     final int i = newID();
     final long v = index(pre, i, value, ATTR);
-    final int n = ne ? 1 << 7 : 0;
     s(Math.min(IO.MAXATTS, dist) << 3 | ATTR);
-    s(n | (byte) (name >> 8)); s(name); s(v >> 32);
+    s(nameId >> 8); s(nameId); s(v >> 32);
     s(v >> 24); s(v >> 16); s(v >> 8); s(v);
-    s(0); s(0); s(0); s(uri);
+    s(0); s(0); s(0); s(uriId);
     s(i >> 24); s(i >> 16); s(i >> 8); s(i);
   }
 
@@ -1080,7 +1062,7 @@
   void indexDelete() { }
 
   /**
-   * Delete a node and its descendants from the corresponding indexes.
+   * Deletes a node and its descendants from the corresponding indexes.
    * @param pre pre value of the node to delete
    * @param size number of descendants
    */
@@ -1101,7 +1083,7 @@
    * @param end end pre value
    * @return table
    */
-  private String toString(final int start, final int end) {
+  public String toString(final int start, final int end) {
     return string(InfoStorage.table(this, start, end));
   }
 
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/data/DataText.java basex-8.2.3/basex-core/src/main/java/org/basex/data/DataText.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/data/DataText.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/data/DataText.java	2015-07-14 10:54:40.000000000 +0000
@@ -133,7 +133,7 @@
   String DOCDECL3 = "\" standalone=\"";
 
   /** HTML. */
-  String HTML = "html";
+  byte[] HTML = token("html");
   /** Doctype output. */
   String DOCTYPE = "<!DOCTYPE ";
   /** Doctype system keyword. */
@@ -230,6 +230,11 @@
   /** HTML: charset. */
   byte[] CHARSET = token("charset");
 
+  /** XHTML namespace. */
+  byte[] XHTML_URI = token("http://www.w3.org/1999/xhtml");
+  /** XML namespace. */
+  byte[] XML_URI = token("http://www.w3.org/XML/1998/namespace");
+
   // TABLE SERIALIZATION ==========================================================================
 
   /** First table Header. */
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/data/DBNodes.java basex-8.2.3/basex-core/src/main/java/org/basex/data/DBNodes.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/data/DBNodes.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/data/DBNodes.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,227 +0,0 @@
-package org.basex.data;
-
-import java.io.*;
-import java.util.*;
-
-import org.basex.core.*;
-import org.basex.io.out.*;
-import org.basex.io.serial.*;
-import org.basex.query.value.node.*;
-import org.basex.util.*;
-import org.basex.util.list.*;
-
-/**
- * This class stores database nodes in an ascending order.
- * Instances of this class are used in the {@link Context} class to
- * reference the currently used, marked, and copied nodes.
- *
- * @author BaseX Team 2005-15, BSD License
- * @author Christian Gruen
- */
-public final class DBNodes implements Result {
-  /** Pre values comprise all documents of the database. */
-  public boolean all;
-  /** Root node. */
-  public final Data data;
-  /** Pre values. */
-  public int[] pres;
-  /** Sorted pre values. */
-  public int[] sorted;
-  /** Full-text position data (for visualization). */
-  private final FTPosData ftpos;
-
-  /**
-   * Constructor, specifying a database and pre values.
-   * @param data data reference
-   * @param pres pre values
-   */
-  public DBNodes(final Data data, final int... pres) {
-    this(data, null, pres);
-  }
-
-  /**
-   * Constructor, specifying a database, pre values and full-text positions.
-   * @param data data reference
-   * @param ftpos ft position data
-   * @param pres pre values
-   */
-  public DBNodes(final Data data, final FTPosData ftpos, final int... pres) {
-    this.data = data;
-    this.ftpos = ftpos;
-    this.pres = pres;
-  }
-
-  @Override
-  public long size() {
-    return pres.length;
-  }
-
-  @Override
-  public boolean equals(final Object obj) {
-    if(!(obj instanceof DBNodes)) return false;
-    final DBNodes n = (DBNodes) obj;
-    final int[] ps = pres, ps2 = n.pres;
-    final int pl = ps.length;
-    if(pl != ps2.length || data != n.data) return false;
-    for(int c = 0; c < pl; ++c) if(ps2[c] != ps[c]) return false;
-    return ftpos == null ? n.ftpos == null : ftpos.equals(n.ftpos);
-  }
-
-  /**
-   * Returns {@code null} if the pre values comprise all documents of the database.
-   * @return self reference or {@code null}
-   */
-  public DBNodes discardDocs() {
-    if(all) return null;
-
-    final IntList docs = data.resources.docs();
-    final int[] ps = pres;
-    final int pl = ps.length;
-    if(pl != docs.size()) return this;
-
-    int c = -1;
-    while(++c < pl && ps[c] == docs.get(c));
-    return c < pl ? this : null;
-  }
-
-  /**
-   * Checks if the specified node is contained in the array.
-   * @param pre pre value
-   * @return true if the node was found
-   */
-  public boolean contains(final int pre) {
-    return find(pre) >= 0;
-  }
-
-  /**
-   * Returns the position of the specified node or the negative value - 1 of
-   * the position where it should have been found.
-   * @param pre pre value
-   * @return true if the node was found
-   */
-  public int find(final int pre) {
-    sort();
-    return Arrays.binarySearch(sorted, pre);
-  }
-
-  /**
-   * Adds or removes the specified pre node.
-   * @param pre pre value
-   */
-  public void toggle(final int pre) {
-    final int[] n = { pre };
-    set(contains(pre) ? except(pres, n) : union(pres, n));
-  }
-
-  /**
-   * Merges the specified array with the existing pre nodes.
-   * @param pre pre value
-   */
-  public void union(final int[] pre) {
-    set(union(pres, pre));
-  }
-
-  /**
-   * Returns full-text position data.
-   * @return position data
-   */
-  public FTPosData ftpos() {
-    return ftpos;
-  }
-
-  /**
-   * Merges two sorted integer arrays via union.
-   * Note that the input arrays must be sorted.
-   * @param pres1 first set
-   * @param pres2 second set
-   * @return resulting set
-   */
-  private static int[] union(final int[] pres1, final int[] pres2) {
-    final int al = pres1.length, bl = pres2.length;
-    final IntList il = new IntList();
-    int a = 0, b = 0;
-    while(a != al && b != bl) {
-      final int d = pres1[a] - pres2[b];
-      il.add(d <= 0 ? pres1[a++] : pres2[b++]);
-      if(d == 0) ++b;
-    }
-    while(a != al) il.add(pres1[a++]);
-    while(b != bl) il.add(pres2[b++]);
-    return il.finish();
-  }
-
-  /**
-   * Subtracts the second from the first array.
-   * Note that the input arrays must be sorted.
-   * @param pres1 first set
-   * @param pres2 second set
-   * @return resulting set
-   */
-  private static int[] except(final int[] pres1, final int[] pres2) {
-    final int al = pres1.length, bl = pres2.length;
-    final IntList il = new IntList();
-    int a = 0, b = 0;
-    while(a != al && b != bl) {
-      final int d = pres1[a] - pres2[b];
-      if(d < 0) il.add(pres1[a]);
-      else ++b;
-      if(d <= 0) ++a;
-    }
-    while(a != al) il.add(pres1[a++]);
-    return il.finish();
-  }
-
-  /**
-   * Sets the specified nodes.
-   * @param nodes values
-   */
-  private void set(final int[] nodes) {
-    pres = nodes;
-    sorted = null;
-  }
-
-  /**
-   * Creates a sorted node array. If the original array is already sorted,
-   * the same reference is used.
-   */
-  private void sort() {
-    if(sorted != null) return;
-    int i = Integer.MIN_VALUE;
-    for(final int n : pres) {
-      if(i > n) {
-        sorted = Arrays.copyOf(pres, pres.length);
-        Arrays.sort(sorted);
-        return;
-      }
-      i = n;
-    }
-    sorted = pres;
-  }
-
-  @Override
-  public void serialize(final Serializer ser) throws IOException {
-    final int pl = pres.length;
-    for(int pre = 0; pre < pl && !ser.finished(); pre++) serialize(ser, pre);
-  }
-
-  @Override
-  public void serialize(final Serializer ser, final int pre) throws IOException {
-    ser.serialize(new FTPosNode(data, pres[pre], ftpos));
-  }
-
-  @Override
-  public String serialize() throws IOException {
-    final ArrayOutput ao = new ArrayOutput();
-    serialize(Serializer.get(ao));
-    return ao.toString();
-  }
-
-  @Override
-  public String toString() {
-    try {
-      return serialize();
-    } catch(final IOException ex) {
-      throw Util.notExpected(ex);
-    }
-  }
-}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/data/DiskData.java basex-8.2.3/basex-core/src/main/java/org/basex/data/DiskData.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/data/DiskData.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/data/DiskData.java	2015-07-14 10:54:40.000000000 +0000
@@ -208,7 +208,7 @@
    * @param type index to be opened
    * @param index index instance
    */
-  private void set(final IndexType type, final Index index) {
+  private void set(final IndexType type, final ValueIndex index) {
     meta.dirty = true;
     switch(type) {
       case TEXT:      textIndex = index; break;
@@ -253,8 +253,8 @@
         write();
         texts.flush();
         values.flush();
-        if(textIndex != null) ((DiskValues) textIndex).flush();
-        if(attrIndex != null) ((DiskValues) attrIndex).flush();
+        if(textIndex != null) textIndex.flush();
+        if(attrIndex != null) attrIndex.flush();
       }
     } catch(final IOException ex) {
       Util.stack(ex);
@@ -332,14 +332,9 @@
   protected void updateText(final int pre, final byte[] value, final int kind) {
     final boolean text = kind != ATTR;
 
-    if(meta.updindex) {
-      // update indexes
-      final int id = id(pre);
-      final byte[] oldval = text(pre, text);
-      final DiskValues index = (DiskValues) (text ? textIndex : attrIndex);
-      // don't index document names
-      if(index != null && kind != DOC) index.replace(oldval, value, id);
-    }
+    // update index; do not index document names
+    final ValueIndex index = text ? textIndex : attrIndex;
+    if(index != null && kind != DOC) index.replace(text(pre, text), value, id(pre));
 
     // reference to text store
     final DataAccess store = text ? texts : values;
@@ -381,14 +376,14 @@
 
   @Override
   protected void indexAdd() {
-    if(!txtBuffer.isEmpty()) ((DiskValues) textIndex).add(txtBuffer);
-    if(!atvBuffer.isEmpty()) ((DiskValues) attrIndex).add(atvBuffer);
+    if(!txtBuffer.isEmpty()) textIndex.add(txtBuffer);
+    if(!atvBuffer.isEmpty()) attrIndex.add(atvBuffer);
   }
 
   @Override
   void indexDelete() {
-    if(!txtBuffer.isEmpty()) ((DiskValues) textIndex).delete(txtBuffer);
-    if(!atvBuffer.isEmpty()) ((DiskValues) attrIndex).delete(atvBuffer);
+    if(!txtBuffer.isEmpty()) textIndex.delete(txtBuffer);
+    if(!atvBuffer.isEmpty()) attrIndex.delete(atvBuffer);
   }
 
   @Override
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/data/FTMatches.java basex-8.2.3/basex-core/src/main/java/org/basex/data/FTMatches.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/data/FTMatches.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/data/FTMatches.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,130 +0,0 @@
-package org.basex.data;
-
-import java.util.*;
-
-import org.basex.util.*;
-import org.basex.util.list.*;
-
-/**
- * AllMatches full-text container, referencing several {@link FTMatch} instances.
- *
- * @author BaseX Team 2005-15, BSD License
- * @author Christian Gruen
- */
-public final class FTMatches extends ElementList implements Iterable<FTMatch> {
-  /** Full-text matches. */
-  public FTMatch[] match = {};
-  /** Position of a token in the query. */
-  public int pos;
-
-  /**
-   * Constructor.
-   */
-  public FTMatches() {
-  }
-
-  /**
-   * Constructor.
-   * @param pos query position
-   */
-  public FTMatches(final int pos) {
-    this.pos = pos;
-  }
-
-  /**
-   * Resets the match container.
-   * @param ps query position
-   */
-  public void reset(final int ps) {
-    pos = ps;
-    size = 0;
-  }
-
-  /**
-   * Adds a match entry.
-   * @param ps position
-   */
-  public void or(final int ps) {
-    or(ps, ps);
-  }
-
-  /**
-   * Adds a match entry.
-   * @param start start position
-   * @param end end position
-   */
-  public void or(final int start, final int end) {
-    add(new FTMatch(1).add(new FTStringMatch(start, end, pos)));
-  }
-
-  /**
-   * Adds a match entry.
-   * @param start start position
-   * @param end end position
-   */
-  public void and(final int start, final int end) {
-    final FTStringMatch sm = new FTStringMatch(start, end, pos);
-    for(final FTMatch m : this) m.add(sm);
-  }
-
-  /**
-   * Adds a match entry.
-   * @param ftm match to be added
-   */
-  public void add(final FTMatch ftm) {
-    if(size == match.length) match = Array.copy(match, new FTMatch[Array.newSize(size)]);
-    match[size++] = ftm;
-  }
-
-  /**
-   * Removes the specified match.
-   * @param index match index
-   */
-  public void delete(final int index) {
-    Array.move(match, index + 1, -1, --size - index);
-  }
-
-  /**
-   * Checks if at least one of the matches contains only includes.
-   * @return result of check
-   */
-  public boolean matches() {
-    for(final FTMatch m : this) if(m.match()) return true;
-    return false;
-  }
-
-  /**
-   * Combines two matches as phrase.
-   * @param all second match list
-   * @param distance word distance
-   * @return true if matches are left
-   */
-  public boolean phrase(final FTMatches all, final int distance) {
-    int a = 0, b = 0, c = 0;
-    while(a < size && b < all.size) {
-      final int e = all.match[b].match[0].start;
-      final int d = e - match[a].match[0].end - distance;
-      if(d == 0) {
-        match[c] = match[a];
-        match[c++].match[0].end = e;
-      }
-      if(d >= 0) ++a;
-      if(d <= 0) ++b;
-    }
-    size = c;
-    return size != 0;
-  }
-
-  @Override
-  public Iterator<FTMatch> iterator() {
-    return new ArrayIterator<>(match, size);
-  }
-
-  @Override
-  public String toString() {
-    final StringBuilder sb = new StringBuilder();
-    sb.append(Util.className(this)).append('[').append(pos).append(']');
-    for(final FTMatch m : this) sb.append("\n  ").append(m);
-    return sb.toString();
-  }
-}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/data/FTMatch.java basex-8.2.3/basex-core/src/main/java/org/basex/data/FTMatch.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/data/FTMatch.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/data/FTMatch.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,95 +0,0 @@
-package org.basex.data;
-
-import java.util.*;
-
-import org.basex.util.*;
-import org.basex.util.list.*;
-
-/**
- * Match full-text container, referencing several {@link FTStringMatch} instances.
- *
- * @author BaseX Team 2005-15, BSD License
- * @author Christian Gruen
- */
-public final class FTMatch extends ElementList implements Iterable<FTStringMatch> {
-  /** String matches. */
-  FTStringMatch[] match;
-
-  /**
-   * Constructor.
-   */
-  public FTMatch() {
-    this(0);
-  }
-
-  /**
-   * Constructor, specifying an initial internal array size.
-   * @param capacity initial array capacity
-   */
-  public FTMatch(final int capacity) {
-    match = new FTStringMatch[capacity];
-  }
-
-  /**
-   * Adds all matches of a full-text match.
-   * @param ftm match to be added
-   * @return self reference
-   */
-  public FTMatch add(final FTMatch ftm) {
-    for(final FTStringMatch sm : ftm) add(sm);
-    return this;
-  }
-
-  /**
-   * Adds a single string match.
-   * @param ftm match to be added
-   * @return self reference
-   */
-  public FTMatch add(final FTStringMatch ftm) {
-    if(size == match.length) match = Array.copy(match, new FTStringMatch[newSize()]);
-    match[size++] = ftm;
-    return this;
-  }
-
-  /**
-   * Checks if the full-text match is not part of the specified match.
-   * @param ftm match to be checked
-   * @return result of check
-   */
-  public boolean notin(final FTMatch ftm) {
-    for(final FTStringMatch s : this) {
-      for(final FTStringMatch sm : ftm) if(!s.in(sm)) return true;
-    }
-    return false;
-  }
-
-  /**
-   * Checks if the match contains no string excludes.
-   * @return result of check
-   */
-  boolean match() {
-    for(final FTStringMatch s : this) if(s.exclude) return false;
-    return true;
-  }
-
-  /**
-   * Sorts the matches by their start and end positions.
-   */
-  public void sort() {
-    Arrays.sort(match, 0, size, null);
-  }
-
-  @Override
-  public Iterator<FTStringMatch> iterator() {
-    return new ArrayIterator<>(match, size);
-  }
-
-  @Override
-  public String toString() {
-    final StringBuilder sb = new StringBuilder();
-    for(final FTStringMatch s : this) {
-      sb.append(sb.length() == 0 ? "" : ", ").append(s);
-    }
-    return Util.className(this) + ' ' + sb;
-  }
-}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/data/FTPosData.java basex-8.2.3/basex-core/src/main/java/org/basex/data/FTPosData.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/data/FTPosData.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/data/FTPosData.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,110 +0,0 @@
-package org.basex.data;
-
-import java.util.*;
-
-import org.basex.util.*;
-import org.basex.util.hash.*;
-import org.basex.util.list.*;
-
-/**
- * This class provides a container for query full-text positions,
- * which is evaluated by the visualizations.
- *
- * @author BaseX Team 2005-15, BSD License
- * @author Christian Gruen
- * @author Sebastian Gath
- */
-public final class FTPosData {
-  /** Position references. */
-  private FTPos[] pos = new FTPos[1];
-  /** Data reference. */
-  private Data dt;
-  /** Number of values. */
-  private int size;
-
-  /**
-   * Adds position data.
-   *
-   * @param data data reference
-   * @param pre pre value
-   * @param all full-text matches
-   */
-  public void add(final Data data, final int pre, final FTMatches all) {
-    if(dt == null) dt = data;
-    else if(dt != data) return;
-
-    // cache all positions
-    final IntSet set = new IntSet();
-    for(final FTMatch ftm : all) {
-      for(final FTStringMatch sm : ftm) {
-        for(int s = sm.start; s <= sm.end; ++s) set.add(s);
-      }
-    }
-
-    // sort and store all positions
-    final IntList il = new IntList(set.toArray()).sort();
-    int c = find(pre);
-    if(c < 0) {
-      c = -c - 1;
-      if(size == pos.length) pos = Arrays.copyOf(pos, Array.newSize(size));
-      Array.move(pos, c, 1, size++ - c);
-      pos[c] = new FTPos(pre, il);
-    } else {
-      pos[c].union(il);
-    }
-  }
-
-  /**
-   * Gets full-text data from the container.
-   * If no data is stored for a pre value, {@code null} is returned.
-   * int[0] : [pos0, ..., posn]
-   * int[1] : [poi0, ..., poin]
-   * @param data data reference
-   * @param pre int pre value
-   * @return int[2][n] full-text data or {@code null}
-   */
-  public FTPos get(final Data data, final int pre) {
-    final int p = find(pre);
-    return p < 0 || dt != data ? null : pos[p];
-  }
-
-  /**
-   * Returns the number of entries.
-   * @return size
-   */
-  public int size() {
-    int c = 0;
-    for(int i = 0; i < size; ++i) c += pos[i].size();
-    return c;
-  }
-
-  @Override
-  public boolean equals(final Object obj) {
-    if(!(obj instanceof FTPosData)) return false;
-    final FTPosData ft = (FTPosData) obj;
-    if(size != ft.size) return false;
-    for(int i = 0; i < size; ++i) {
-      if(pos[i].pre != ft.pos[i].pre || !Arrays.equals(
-          pos[i].list.toArray(), ft.pos[i].list.toArray())) return false;
-    }
-    return true;
-  }
-
-  /**
-   * Returns the index of the specified pre value.
-   * @param pre int pre value
-   * @return index, or negative index - 1 if pre value is not found
-   */
-  private int find(final int pre) {
-    // binary search
-    int l = 0, h = size - 1;
-    while(l <= h) {
-      final int m = l + h >>> 1;
-      final int c = pos[m].pre - pre;
-      if(c == 0) return m;
-      if(c < 0) l = m + 1;
-      else h = m - 1;
-    }
-    return -l - 1;
-  }
-}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/data/FTPos.java basex-8.2.3/basex-core/src/main/java/org/basex/data/FTPos.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/data/FTPos.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/data/FTPos.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,61 +0,0 @@
-package org.basex.data;
-
-import org.basex.util.hash.*;
-import org.basex.util.list.*;
-
-/**
- * This class contains full-text positions for a single database node.
- *
- * @author BaseX Team 2005-15, BSD License
- * @author Christian Gruen
- */
-public final class FTPos {
-  /** Pre value. */
-  final int pre;
-  /** Positions. */
-  IntList list;
-
-  /**
-   * Constructor.
-   * @param pre pre value
-   * @param list sorted positions
-   */
-  FTPos(final int pre, final IntList list) {
-    this.pre = pre;
-    this.list = list;
-  }
-
-  /**
-   * Merges the specified position arrays.
-   * @param pos sorted positions
-   */
-  void union(final IntList pos) {
-    final int ps = list.size(), ls = pos.size();
-    final IntSet set = new IntSet(ps + ls);
-    for(int p = 0, s = ps; p < s; p++) set.add(list.get(p));
-    for(int l = 0, s = ls; l < s; l++) set.add(pos.get(l));
-    list = new IntList(set.toArray()).sort();
-  }
-
-  /**
-   * Checks if the specified position is found.
-   * @param pos position to be found
-   * @return result of check
-   */
-  public boolean contains(final int pos) {
-    return list.sortedIndexOf(pos) >= 0;
-  }
-
-  /**
-   * Returns the number of positions.
-   * @return number of positions
-   */
-  public int size() {
-    return list.size();
-  }
-
-  @Override
-  public String toString() {
-    return pre + ": " + list;
-  }
-}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/data/FTStringMatch.java basex-8.2.3/basex-core/src/main/java/org/basex/data/FTStringMatch.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/data/FTStringMatch.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/data/FTStringMatch.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,67 +0,0 @@
-package org.basex.data;
-
-/**
- * Single full-text string match.
- *
- * @author BaseX Team 2005-15, BSD License
- * @author Christian Gruen
- */
-public final class FTStringMatch implements Comparable<FTStringMatch> {
-  /** Position of the token in the query. */
-  public final int pos;
-  /** Start position. */
-  public final int start;
-  /** End position. */
-  public int end;
-  /** Exclude flag. */
-  public boolean exclude;
-  /** Gaps (non-contiguous) flag. */
-  public boolean gaps;
-
-  /**
-   * Constructor.
-   * @param start start position
-   * @param end end position
-   * @param pos query pos
-   */
-  FTStringMatch(final int start, final int end, final int pos) {
-    this.start = start;
-    this.end = end;
-    this.pos = pos;
-  }
-
-  /**
-   * Checks if the match is included in the specified match.
-   * @param mtc match to be compared
-   * @return result of check
-   */
-  boolean in(final FTStringMatch mtc) {
-    return start >= mtc.start && end <= mtc.end;
-  }
-
-  @Override
-  public boolean equals(final Object ftm) {
-    if(!(ftm instanceof FTStringMatch)) return false;
-    final FTStringMatch sm = (FTStringMatch) ftm;
-    return start == sm.start && end == sm.end;
-  }
-
-  @Override
-  public int compareTo(final FTStringMatch sm) {
-    final int s = start - sm.start;
-    return s == 0 ? end - sm.end : s;
-  }
-
-  @Override
-  public int hashCode() {
-    final int h = start + 1;
-    return (h << 5) - h + end;
-  }
-
-  @Override
-  public String toString() {
-    final StringBuilder sb = new StringBuilder().append(pos);
-    sb.append(':').append(start).append('-').append(end);
-    return exclude ? "not(" + sb + ')' : sb.toString();
-  }
-}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/data/MemData.java basex-8.2.3/basex-core/src/main/java/org/basex/data/MemData.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/data/MemData.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/data/MemData.java	2015-07-14 10:54:40.000000000 +0000
@@ -38,7 +38,7 @@
    * @param options database options
    */
   private MemData(final Names elemNames, final Names attrNames, final PathSummary paths,
-      final Namespaces nspaces, final Index textIndex, final Index attrIndex,
+      final Namespaces nspaces, final ValueIndex textIndex, final ValueIndex attrIndex,
       final MainOptions options) {
 
     super(new MetaData(options));
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/data/Namespaces.java basex-8.2.3/basex-core/src/main/java/org/basex/data/Namespaces.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/data/Namespaces.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/data/Namespaces.java	2015-07-14 10:54:40.000000000 +0000
@@ -19,32 +19,30 @@
  * @author Christian Gruen
  */
 public final class Namespaces {
-  /** Stack with references to default namespaces. */
-  private final IntList defaults = new IntList(2);
   /** Namespace prefixes. */
-  private final TokenSet prefs;
+  private final TokenSet prefixes;
   /** Namespace URIs. */
   private final TokenSet uris;
   /** Root node. */
   private final NSNode root;
 
-  /** Indicates if new namespaces have been added for an XML node. */
-  private boolean newns;
+  /** Stack with references to current default namespaces. */
+  private final IntList defaults = new IntList(2);
   /** Current level. Index starts at 1 (required by XQUF operations). */
   private int level = 1;
   /** Current namespace node. */
-  private NSNode current;
+  private NSNode cursor;
 
-  // Building Namespaces ================================================================
+  // Creating and Writing Namespaces ==============================================================
 
   /**
    * Empty constructor.
    */
   public Namespaces() {
-    prefs = new TokenSet();
+    prefixes = new TokenSet();
     uris = new TokenSet();
     root = new NSNode(-1);
-    current = root;
+    cursor = root;
   }
 
   /**
@@ -53,10 +51,10 @@
    * @throws IOException I/O exception
    */
   Namespaces(final DataInput in) throws IOException {
-    prefs = new TokenSet(in);
+    prefixes = new TokenSet(in);
     uris = new TokenSet(in);
     root = new NSNode(in, null);
-    current = root;
+    cursor = root;
   }
 
   /**
@@ -65,435 +63,353 @@
    * @throws IOException I/O exception
    */
   void write(final DataOutput out) throws IOException {
-    prefs.write(out);
+    prefixes.write(out);
     uris.write(out);
     root.write(out);
   }
 
-  /**
-   * Prepares the generation of new namespaces.
-   */
-  public void prepare() {
-    final int nu = defaults.get(level);
-    defaults.set(++level, nu);
-    newns = false;
-  }
+  // Requesting Namespaces Globally ===============================================================
 
   /**
-   * Adds the specified namespace to the namespace structure of the current element.
-   * @param pref prefix
-   * @param uri uri
-   * @param pre pre value
-   * @return new NSNode if a new one has been created, {@code null} otherwise
-   */
-  public NSNode add(final byte[] pref, final byte[] uri, final int pre) {
-    NSNode node = null;
-    if(!newns) {
-      node = new NSNode(pre);
-      current.add(node);
-      current = node;
-      newns = true;
-    }
-    final int k = prefs.put(pref);
-    final int v = uris.put(uri);
-    current.add(k, v);
-    if(pref.length == 0) defaults.set(level, v);
-    return node;
-  }
-
-  /**
-   * Closes a namespace node.
-   * @param pre current pre value
+   * Returns if no namespaces exist.
+   * Note that the container size does not change if namespaces are deleted.
+   * This function is mainly used to decide namespaces need to be considered in query optimizations.
+   * @return result of check
    */
-  public void close(final int pre) {
-    while(current.pr >= pre && current.parent != null) current = current.parent;
-    --level;
+  public boolean isEmpty() {
+    return uris.isEmpty();
   }
 
-  // Requesting Namespaces ==============================================================
-
   /**
-   * Returns the size of the uri container.
-   * Note that the container size does not change if namespaces are deleted.
-   * This function is basically used to decide if there are any namespaces at all,
-   * and if namespaces need to be considered in query optimizations.
-   * @return number of uri references
+   * Returns the number of namespaces that have been stored so far.
+   * @return number of entries
    */
   public int size() {
     return uris.size();
   }
 
   /**
-   * Returns the default namespace of the database or {@code null}
-   * if several (default or prefixed) namespaces are defined.
-   * @return global default namespace, or {@code null}
+   * Returns a prefix for the specified id.
+   * @param id id of prefix
+   * @return prefix
    */
-  public byte[] globalNS() {
-    // no namespaces defined: default namespace is empty
-    if(root.sz == 0) return Token.EMPTY;
-    // more than one namespace defined: skip test
-    if(root.sz > 1) return null;
-    // check namespaces of first child
-    final NSNode n = root.children[0];
-
-    // namespace has more children; skip traversal
-    if(n.sz != 0 || n.pr != 1 || n.values.length != 2) return null;
-    // return default namespace or null
-    return prefix(n.values[0]).length == 0 ? uri(n.values[1]) : null;
+  public byte[] prefix(final int id) {
+    return prefixes.key(id);
   }
 
   /**
-   * Returns the specified namespace URI.
-   * @param id namespace URI reference
-   * @return prefix
+   * Returns a namespace uri for the specified id.
+   * @param id id of namespace uri
+   * @return namespace uri
    */
   public byte[] uri(final int id) {
     return uris.key(id);
   }
 
   /**
-   * Returns the namespace URI reference for the specified name and pre value,
-   * or {@code 0} if namespace cannot be found.
-   * @param name element/attribute name
-   * @param pre pre value
-   * @param data data reference
-   * @return namespace URI reference
+   * Returns the id of the specified namespace uri.
+   * @param uri namespace URI
+   * @return id, or {@code 0} if no entry is found
    */
-  public int uri(final byte[] name, final int pre, final Data data) {
-    return uri(Token.prefix(name), current.find(pre, data));
+  public int uriId(final byte[] uri) {
+    return uris.id(uri);
   }
 
   /**
-   * Returns a reference to the specified namespace URI,
-   * or {@code 0} if the URI is empty or no namespace is found.
-   * @param uri namespace URI
-   * @return reference, or {@code 0}
+   * Returns the id of the specified prefix.
+   * @param prefix prefix
+   * @return id, or {@code 0} if no entry is found
    */
-  public int uri(final byte[] uri) {
-    return uri.length == 0 ? 0 : uris.id(uri);
+  public int prefixId(final byte[] prefix) {
+    return prefixes.id(prefix);
   }
 
   /**
-   * Returns the namespace URI reference for the specified name,
-   * or {@code 0} if no namespace is found.
-   * @param name element/attribute name
-   * @param elem element flag
-   * @return namespace
+   * Returns the default namespace uri for all documents of the database.
+   * @return global default namespace, or {@code null} if there is more than one such namespace
    */
-  public int uri(final byte[] name, final boolean elem) {
-    if(uris.isEmpty()) return 0;
-    final byte[] pref = Token.prefix(name);
-    int nu = elem ? defaults.get(level) : 0;
-    if(pref.length != 0) nu = uri(pref, current);
-    return nu;
+  public byte[] globalUri() {
+    // no namespaces defined: default namespace is empty
+    final int ch = root.children();
+    if(ch == 0) return Token.EMPTY;
+    // give up if more than one namespace is defined
+    if(ch > 1) return null;
+    // give up if child node has more children or more than one namespace
+    final NSNode child = root.child(0);
+    final int[] values = child.values();
+    if(child.children() > 0 || child.pre() != 1 || values.length != 2) return null;
+    // give up if namespace has a non-empty prefix
+    if(prefix(values[0]).length != 0) return null;
+    // return default namespace
+    return uri(values[1]);
   }
 
+  // Requesting Namespaces Based on Context =======================================================
+
   /**
-   * Returns the current namespaces node.
-   * @return current namespace node
+   * Returns the id of a namespace uri for the specified prefix.
+   * @param prefix prefix
+   * @param element indicates if the prefix belongs to an element or attribute name
+   * @return id of namespace uri, or {@code 0} if no entry is found
    */
-  NSNode getCurrent() {
-    return current;
+  public int uriIdForPrefix(final byte[] prefix, final boolean element) {
+    if(isEmpty()) return 0;
+    return prefix.length != 0 ? uriId(prefix, cursor) : element ? defaults.get(level) : 0;
   }
 
   /**
-   * Returns the specified prefix.
-   * @param id prefix reference
-   * @return prefix
+   * Returns the id of a namespace uri for the specified prefix and pre value.
+   * @param prefix prefix
+   * @param pre pre value
+   * @param data data reference
+   * @return id of namespace uri, or {@code 0} if no entry is found
    */
-  byte[] prefix(final int id) {
-    return prefs.key(id);
+  public int uriIdForPrefix(final byte[] prefix, final int pre, final Data data) {
+    return uriId(prefix, cursor.find(pre, data));
   }
 
   /**
-   * Returns the prefix and URI references of all namespaces defined for the node with
-   * the specified pre value.
-   * @param pre pre value
-   * @param data data reference
-   * @return namespace references
+   * Returns the id of a namespace uri for the specified prefix and node.
+   * @param prefix prefix
+   * @param node node to start with
+   * @return id of the namespace uri, or {@code 0} if namespace is not found.
    */
-  int[] get(final int pre, final Data data) {
-    return current.find(pre, data).values;
+  private int uriId(final byte[] prefix, final NSNode node) {
+    final int prefId = prefixes.id(prefix);
+    if(prefId == 0) return 0;
+
+    NSNode nd = node;
+    while(nd != null) {
+      final int uriId = nd.uri(prefId);
+      if(uriId != 0) return uriId;
+      nd = nd.parent();
+    }
+    return 0;
   }
 
   /**
-   * Returns a map with all namespaces that are valid for the specified pre value.
+   * Returns all namespace prefixes and uris that are declared for the specified pre value.
+   * Should only be called for element nodes.
    * @param pre pre value
    * @param data data reference
-   * @return scope
+   * @return key and value ids
    */
-  TokenMap scope(final int pre, final Data data) {
-    final TokenMap nsScope = new TokenMap();
-    NSNode node = current;
-    do {
-      final int[] values = node.values;
-      final int vl = values.length;
-      for(int v = 0; v < vl; v += 2) {
-        nsScope.put(prefix(values[v]), uri(values[v + 1]));
-      }
-      final int pos = node.find(pre);
-      if(pos < 0) break;
-      node = node.children[pos];
-    } while(node.pr <= pre && pre < node.pr + data.size(node.pr, Data.ELEM));
-    return nsScope;
+  public Atts values(final int pre, final Data data) {
+    final Atts as = new Atts();
+    final int[] values = cursor.find(pre, data).values();
+    final int nl = values.length;
+    for(int n = 0; n < nl; n += 2) as.add(prefix(values[n]), uri(values[n + 1]));
+    return as;
   }
 
   /**
-   * Finds the nearest namespace node on the ancestor axis of the insert
-   * location and sets it as new root. Possible candidates for this node are collected
-   * and the match with the highest pre value between ancestors and candidates
-   * is determined.
+   * Finds the nearest namespace node on the ancestor axis of the insert location and sets it as new
+   * root. Possible candidates for this node are collected and the match with the highest pre value
+   * between ancestors and candidates is determined.
    * @param pre pre value
    * @param data data reference
    */
   void root(final int pre, final Data data) {
     // collect possible candidates for namespace root
     final List<NSNode> cand = new LinkedList<>();
-    NSNode node = root;
-    cand.add(node);
-    for(int p; (p = node.find(pre)) > -1;) {
+    NSNode nd = root;
+    cand.add(nd);
+    for(int p; (p = nd.find(pre)) > -1;) {
       // add candidate to stack
-      node = node.children[p];
-      cand.add(0, node);
+      nd = nd.child(p);
+      cand.add(0, nd);
     }
 
-    node = root;
+    nd = root;
     if(cand.size() > 1) {
       // compare candidates to ancestors of pre value
       int ancPre = pre;
       // take first candidate from stack
       NSNode curr = cand.remove(0);
-      while(ancPre > -1 && node == root) {
-        // this is the new root
-        if(curr.pr == ancPre) node = curr;
-        // if the current candidate's pre value is lower than the current
-        // ancestor of par or par itself, we have to look for a potential
-        // match for this candidate. therefore we iterate through ancestors
-        // until we find one with a lower than or the same pre value as the
+      while(ancPre > -1 && nd == root) {
+        // if the current candidate's pre value is lower than the current ancestor of par or par
+        // itself, we have to look for a potential match for this candidate. therefore we iterate
+        // through ancestors until we find one with a lower than or the same pre value as the
         // current candidate.
-        else if(curr.pr < ancPre) {
-          while((ancPre = data.parent(ancPre, data.kind(ancPre))) > curr.pr);
-          if(curr.pr == ancPre) node = curr;
-        }
+        while(ancPre > curr.pre()) ancPre = data.parent(ancPre, data.kind(ancPre));
+        // this is the new root
+        if(ancPre == curr.pre()) nd = curr;
         // no potential for infinite loop, because dummy root is always a match,
         // in this case ancPre ends iteration
         if(!cand.isEmpty()) curr = cand.remove(0);
       }
     }
 
-    final int uri = uri(Token.EMPTY, pre, data);
-    defaults.set(level, uri);
-    // remind uri before insert of first node n to connect siblings of n to
-    // according namespace
-    defaults.set(level - 1, uri);
-    current = node;
+    final int uriId = uriIdForPrefix(Token.EMPTY, pre, data);
+    defaults.set(level, uriId);
+    // remember uri before insert of first node n to connect siblings of n to according namespace
+    defaults.set(level - 1, uriId);
+    cursor = nd;
   }
 
   /**
-   * Returns the namespace URI reference for the specified prefix and node,
-   * or {@code 0} if no namespace is found.
-   * @param pref prefix
-   * @param node node to start with
-   * @return namespace URI reference
-   */
-  private int uri(final byte[] pref, final NSNode node) {
-    final int id = prefs.id(pref);
-    if(id == 0) return 0;
-
-    NSNode n = node;
-    while(n != null) {
-      final int u = n.uri(id);
-      if(u != 0) return u;
-      n = n.parent;
-    }
-    return 0;
-  }
-
-  /**
-   * Returns all namespace nodes in the namespace structure with a minimum
-   * PRE value.
-   * @param pre minimum PRE value of a namespace node.
-   * @return List of namespace nodes with a minimum PRE value of pre
+   * Caches and returns all namespace nodes in the namespace structure with a minimum pre value.
+   * @param pre minimum pre value of a namespace node.
+   * @return list of namespace nodes
    */
-  List<NSNode> getNSNodes(final int pre) {
-    final List<NSNode> l = new ArrayList<>();
-    addNSNodes(root, l, pre);
-    return l;
+  ArrayList<NSNode> cache(final int pre) {
+    final ArrayList<NSNode> list = new ArrayList<>();
+    addNodes(root, list, pre);
+    return list;
   }
 
   /**
-   * Recursively adds namespace nodes to the given list, starting at the children of the given node.
-   * @param curr current namespace node
+   * Recursively adds namespace nodes to the a list, starting with the children of a node.
+   * @param node current namespace node
    * @param list list with namespace nodes
    * @param pre pre value
    */
-  private static void addNSNodes(final NSNode curr, final List<NSNode> list, final int pre) {
-    final int sz = curr.sz;
-    int s = find(curr, pre);
-    while(s > 0 && (s == sz || curr.children[s].pr >= pre)) s--;
-    for(; s < sz; s++) {
-      final NSNode ch = curr.children[s];
-      if(ch.pr >= pre) list.add(ch);
-      addNSNodes(ch, list, pre);
+  private static void addNodes(final NSNode node, final List<NSNode> list, final int pre) {
+    final int sz = node.children();
+    int i = Math.max(0, node.find(pre));
+    while(i > 0 && (i == sz || node.child(i).pre() >= pre)) i--;
+    for(; i < sz; i++) {
+      final NSNode child = node.child(i);
+      if(child.pre() >= pre) list.add(child);
+      addNodes(child, list, pre);
     }
   }
 
-  /**
-   * Returns the index of the specified pre value.
-   * @param curr current namespace node
-   * @param pre int pre value
-   * @return index
-   */
-  private static int find(final NSNode curr, final int pre) {
-    // binary search
-    int l = 0, h = curr.sz - 1;
-    while(l <= h) {
-      final int m = l + h >>> 1;
-      final int c = curr.children[m].pr - pre;
-      if(c == 0) return m;
-      if(c < 0) l = m + 1;
-      else h = m - 1;
-    }
-    return l;
-  }
+  // Updating Namespaces ==========================================================================
 
-  // Updating Namespaces ================================================================
   /**
-   * Deletes the specified namespace URI from the root node.
-   * @param uri namespace URI reference
+   * Sets a namespace cursor.
+   * @param node namespace node
    */
-  public void delete(final byte[] uri) {
-    final int id = uris.id(uri);
-    if(id != 0) current.delete(id);
+  void cursor(final NSNode node) {
+    cursor = node;
   }
 
   /**
-   * Deletes the specified number of entries from the namespace structure.
-   * @param pre pre value of the first node to delete
-   * @param data data reference
-   * @param size number of entries to be deleted
+   * Returns the current namespace cursor.
+   * @return current namespace node
    */
-  void delete(final int pre, final int size, final Data data) {
-    NSNode nd = current.find(pre, data);
-    if(nd.pr == pre) nd = nd.parent;
-    while(nd != null) {
-      nd.delete(pre, size);
-      nd = nd.parent;
-    }
-
-    decrementPre(root, pre, size);
+  NSNode cursor() {
+    return cursor;
   }
 
   /**
-   * Recursive shifting of pre values after delete operations.
-   * @param node current namespace node which is updated if necessary
-   * @param pre update location
-   * @param size size of inserted/deleted node
+   * Increases the level counter and sets a new default namespace.
    */
-  private static void decrementPre(final NSNode node, final int pre, final int size) {
-    if(node.pr >= pre + size) node.pr -= size;
-    final int ns = node.sz;
-    for(int n = 0; n < ns; n++) decrementPre(node.children[n], pre, size);
+  public void open() {
+    final int nu = defaults.get(level);
+    defaults.set(++level, nu);
   }
 
   /**
-   * Increments the PRE value of all namespace nodes in the given list by the given size.
-   * @param list list of namespace nodes
-   * @param inc size to increment
+   * Adds namespaces to a new namespace child node and sets this node as new cursor.
+   * @param pre pre value
+   * @param atts namespaces
    */
-  static void incrementPre(final List<NSNode> list, final int inc) {
-    for(final NSNode node : list) node.pr += inc;
+  public void open(final int pre, final Atts atts) {
+    open();
+    if(!atts.isEmpty()) {
+      final NSNode nd = new NSNode(pre);
+      cursor.add(nd);
+      cursor = nd;
+
+      final int as = atts.size();
+      for(int a = 0; a < as; a++) {
+        final byte[] pref = atts.name(a), uri = atts.value(a);
+        final int prefId = prefixes.put(pref), uriId = uris.put(uri);
+        nd.add(prefId, uriId);
+        if(pref.length == 0) defaults.set(level, uriId);
+      }
+    }
   }
 
   /**
-   * Adds a namespace for the specified pre value.
+   * Adds a single namespace for the specified pre value.
    * @param pre pre value
-   * @param par parent value
-   * @param pref prefix
-   * @param uri uri
+   * @param prefix prefix
+   * @param uri namespace uri
    * @param data data reference
-   * @return uri reference
+   * @return id of namespace uri
    */
-  public int add(final int pre, final int par, final byte[] pref, final byte[] uri,
-      final Data data) {
-
-    // don't store XML namespace
-    if(Token.eq(pref, Token.XML)) return 0;
+  public int add(final int pre, final byte[] prefix, final byte[] uri, final Data data) {
+    final int prefId = prefixes.put(prefix), uriId = uris.put(uri);
+    NSNode nd = cursor.find(pre, data);
+    if(nd.pre() != pre) {
+      final NSNode child = new NSNode(pre);
+      nd.add(child);
+      nd = child;
+    }
+    nd.add(prefId, uriId);
+    return uriId;
+  }
 
-    final NSNode nd = current.find(par, data);
-    final NSNode t = new NSNode(pre);
-
-    final int k = prefs.put(pref);
-    final int v = uris.put(uri);
-    if(nd.pr == pre) {
-      nd.add(k, v);
-    } else {
-      t.add(k, v);
-      nd.add(t);
+  /**
+   * Closes a namespace node.
+   * @param pre current pre value
+   */
+  public void close(final int pre) {
+    while(cursor.pre() >= pre) {
+      final NSNode nd = cursor.parent();
+      if(nd == null) break;
+      cursor = nd;
     }
-    return v;
+    --level;
+  }
+
+  /**
+   * Deletes the specified namespace URI from the root node.
+   * @param uri namespace URI reference
+   */
+  public void delete(final byte[] uri) {
+    final int id = uris.id(uri);
+    if(id != 0) cursor.delete(id);
   }
 
   /**
-   * Setter for namespaces root node.
-   * @param node new root
+   * Deletes the specified number of entries from the namespace structure.
+   * @param pre pre value of the first node to delete
+   * @param data data reference
+   * @param size number of entries to be deleted
    */
-  void setCurrent(final NSNode node) {
-    current = node;
+  void delete(final int pre, final int size, final Data data) {
+    NSNode nd = cursor.find(pre, data);
+    if(nd.pre() == pre) nd = nd.parent();
+    while(nd != null) {
+      nd.delete(pre, size);
+      nd = nd.parent();
+    }
+    root.decrementPre(pre, size);
   }
 
-  // Printing Namespaces ================================================================
+  // Printing Namespaces ==========================================================================
 
   /**
-   * Returns a tabular representation of the namespaces.
-   * @param start start pre value
-   * @param end end pre value
+   * Returns a tabular representation of the namespace entries.
+   * @param start first pre value
+   * @param end last pre value
    * @return namespaces
    */
   public byte[] table(final int start, final int end) {
-    if(root.sz == 0) return Token.EMPTY;
+    if(root.children() == 0) return Token.EMPTY;
 
     final Table t = new Table();
-    t.header.add(TABLEID);
+    t.header.add(TABLENS);
     t.header.add(TABLEPRE);
     t.header.add(TABLEDIST);
     t.header.add(TABLEPREF);
     t.header.add(TABLEURI);
     for(int i = 0; i < 3; ++i) t.align.add(true);
-    table(t, root, start, end);
+    root.table(t, start, end, this);
     return t.contents.isEmpty() ? Token.EMPTY : t.finish();
   }
 
   /**
-   * Adds the namespace structure for a node to the specified table.
-   * @param table table
-   * @param node namespace node
-   * @param start start pre value
-   * @param end end pre value
-   */
-  private void table(final Table table, final NSNode node, final int start, final int end) {
-    final int[] values = node.values;
-    final int vl = values.length;
-    for(int i = 0; i < vl; i += 2) {
-      if(node.pr < start || node.pr > end) continue;
-      final TokenList tl = new TokenList();
-      tl.add(values[i + 1]);
-      tl.add(node.pr);
-      tl.add(node.pr - node.parent.pr);
-      tl.add(prefs.key(values[i]));
-      tl.add(uris.key(values[i + 1]));
-      table.contents.add(tl);
-    }
-    for(int i = 0; i < node.sz; i++) table(table, node.children[i], start, end);
-  }
-
-  /**
    * Returns namespace information.
    * @return info string
    */
   public byte[] info() {
     final TokenObjMap<TokenList> map = new TokenObjMap<>();
-    info(map, root);
+    root.info(map, this);
     final TokenBuilder tb = new TokenBuilder();
     for(final byte[] key : map) {
       tb.add("  ");
@@ -515,34 +431,13 @@
   }
 
   /**
-   * Adds namespace information for the specified node to a map.
-   * @param map namespace map
-   * @param node namespace node
-   */
-  private void info(final TokenObjMap<TokenList> map, final NSNode node) {
-    final int[] values = node.values;
-    final int vl = values.length;
-    for(int v = 0; v < vl; v += 2) {
-      final byte[] key = uris.key(values[v + 1]);
-      final byte[] val = prefs.key(values[v]);
-      TokenList old = map.get(key);
-      if(old == null) {
-        old = new TokenList();
-        map.put(key, old);
-      }
-      if(!old.contains(val)) old.add(val);
-    }
-    for(final NSNode c : node.children) info(map, c);
-  }
-
-  /**
    * Returns a string representation of the namespaces.
    * @param start start pre value
    * @param end end pre value
    * @return string
    */
   public String toString(final int start, final int end) {
-    return root.print(this, start, end);
+    return root.toString(this, start, end);
   }
 
   @Override
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/data/NSNode.java basex-8.2.3/basex-core/src/main/java/org/basex/data/NSNode.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/data/NSNode.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/data/NSNode.java	2015-07-14 10:54:40.000000000 +0000
@@ -8,6 +8,8 @@
 import org.basex.io.in.DataInput;
 import org.basex.io.out.DataOutput;
 import org.basex.util.*;
+import org.basex.util.hash.*;
+import org.basex.util.list.*;
 
 /**
  * This class stores a single namespace node.
@@ -16,25 +18,25 @@
  * @author Christian Gruen
  */
 final class NSNode {
-  /** Children. */
-  NSNode[] children;
+  /** Child nodes. */
+  private NSNode[] nodes;
   /** Number of children. */
-  int sz;
+  private int size;
   /** Parent node. */
-  NSNode parent;
-  /** References to Prefix/URI pairs. */
-  int[] values;
+  private NSNode parent;
+  /** Dense array with ids of prefix/namespace uri pairs. */
+  private int[] values;
   /** Pre value. */
-  int pr;
+  private int pre;
 
   /**
    * Default constructor.
    * @param pre pre value
    */
   NSNode(final int pre) {
+    this.pre = pre;
     values = new int[0];
-    children = new NSNode[0];
-    pr = pre;
+    nodes = new NSNode[0];
   }
 
   /**
@@ -45,11 +47,11 @@
    */
   NSNode(final DataInput in, final NSNode parent) throws IOException {
     this.parent = parent;
-    pr = in.readNum();
+    pre = in.readNum();
     values = in.readNums();
-    sz = in.readNum();
-    children = new NSNode[sz];
-    for(int c = 0; c < sz; ++c) children[c] = new NSNode(in, this);
+    size = in.readNum();
+    nodes = new NSNode[size];
+    for(int n = 0; n < size; ++n) nodes[n] = new NSNode(in, this);
   }
 
   /**
@@ -58,106 +60,117 @@
    * @throws IOException I/O exception
    */
   void write(final DataOutput out) throws IOException {
-    out.writeNum(pr);
+    out.writeNum(pre);
     out.writeNums(values);
-    out.writeNum(sz);
-    for(int c = 0; c < sz; ++c) children[c].write(out);
+    out.writeNum(size);
+    for(int c = 0; c < size; ++c) nodes[c].write(out);
   }
 
   /**
-   * Adds the specified node into the child array, which is sorted by pre values.
-   * @param node child node
+   * Returns the specified child.
+   * @param i index
+   * @return child
    */
-  void add(final NSNode node) {
-    if(sz == children.length)
-      children = Array.copy(children, new NSNode[Array.newSize(sz)]);
-
-    // find inserting position
-    int s = find(node.pr);
-    if(s < 0 || node.pr != children[s].pr) s++;
+  NSNode child(final int i) {
+    return nodes[i];
+  }
 
-    System.arraycopy(children, s, children, s + 1, sz++ - s);
-    children[s] = node;
-    node.parent = this;
+  /**
+   * Returns the number of children.
+   * @return number of children
+   */
+  int children() {
+    return size;
   }
 
   /**
-   * Adds the specified prefix and URI reference.
-   * @param prefix prefix reference
-   * @param uri uri reference
+   * Returns the pre value.
+   * @return pre value
    */
-  void add(final int prefix, final int uri) {
-    final int s = values.length;
-    values = Arrays.copyOf(values, s + 2);
-    values[s] = prefix;
-    values[s + 1] = uri;
+  int pre() {
+    return pre;
   }
 
   /**
-   * Recursively deletes the specified namespace URI reference.
-   * @param uri namespace URI reference
+   * Returns the parent node.
+   * @return parent node
    */
-  void delete(final int uri) {
-    for(int c = 0; c < sz; ++c) children[c].delete(uri);
+  NSNode parent() {
+    return parent;
+  }
 
-    final int vl = values.length;
-    for(int v = 0; v < vl; v += 2) {
-      if(values[v + 1] != uri) continue;
-      final int[] vals = new int[vl - 2];
-      System.arraycopy(values, 0, vals, 0, v);
-      System.arraycopy(values, v + 2, vals, v, vl - v - 2);
-      values = vals;
-      break;
-    }
+  /**
+   * Returns the ids of prefix/namespace uri pairs.
+   * @return prefix/namespace uri pairs
+   */
+  int[] values() {
+    return values;
   }
 
-  // Requesting Namespaces ====================================================
+  // Requesting Namespaces ========================================================================
 
   /**
-   * Finds the closest namespace node for the specified pre value.
-   * @param pre pre value
+   * Finds the namespace node that is located closest to the specified pre value.
+   * @param p pre value
    * @param data data reference
    * @return node
    */
-  NSNode find(final int pre, final Data data) {
-    final int s = find(pre);
-    // no match found: return current node
+  NSNode find(final int p, final Data data) {
+    // return this node if the pre values of all children are greater than the searched value
+    final int s = find(p);
     if(s == -1) return this;
-    final NSNode ch = children[s];
-    final int cp = ch.pr;
+
+    final NSNode ch = nodes[s];
+    final int cp = ch.pre;
     // return exact hit
-    if(cp == pre) return ch;
+    if(cp == p) return ch;
     // found node is preceding sibling
-    if(cp + data.size(cp, Data.ELEM) <= pre) return this;
+    if(cp + data.size(cp, Data.ELEM) <= p) return this;
     // continue recursive search
-    return children[s].find(pre, data);
+    return nodes[s].find(p, data);
   }
 
   /**
-   * Finds a specific pre value in the child array utilizing binary search
-   * and returns its position if it is contained.
-   * If it is not contained, it returns the position of the biggest element in
-   * the array that is still smaller than p. If all elements in the array are
-   * bigger, it returns -1.
-   * @param pre pre value
-   * @return position of node in child array.
+   * Locates a child node with the specified pre value.
+   * <ul>
+   *   <li> If the value is found, the position of the child node is returned.</li>
+   *   <li> Otherwise, the position of the last child with a smaller pre value is returned.</li>
+   *   <li> -1 is returned if all children have greater pre values.</li>
+   * </ul>
+   * @param p pre value
+   * @return position of the child node
    */
-  int find(final int pre) {
-    int l = 0, h = sz - 1;
+  int find(final int p) {
+    int l = 0, h = size - 1;
     while(l <= h) { // binary search
-      final int m = l + h >>> 1;
-      final int v = children[m].pr;
-      if(v == pre) return m;
-      if(v < pre) l = m + 1;
+      final int m = l + h >>> 1, v = nodes[m].pre;
+      if(v == p) return m;
+      if(v < p) l = m + 1;
       else h = m - 1;
     }
     return l - 1;
   }
 
   /**
-   * Returns the namespace URI reference for the specified prefix.
+   * Returns the index of the specified pre value.
+   * @param p int pre value
+   * @return index, or possible insertion position
+   */
+  int find2(final int p) {
+    int l = 0, h = size - 1;
+    while(l <= h) { // binary search
+      final int m = l + h >>> 1, v = nodes[m].pre;
+      if(v == p) return m;
+      if(v < p) l = m + 1;
+      else h = m - 1;
+    }
+    return l;
+  }
+
+  /**
+   * Returns the id of the namespace uri for the specified prefix.
    * @param prefix prefix reference
-   * @return uri reference or {@code 0}
+   * @return if of the namespace uri, or {@code 0} if none is found
    */
   int uri(final int prefix) {
     final int[] vls = values;
@@ -166,52 +179,102 @@
     return 0;
   }
 
+  // Updating Namespaces ==========================================================================
+
   /**
-   * Deletes nodes in the specified range (p .. p + sz - 1) and updates the
-   * following pre values
-   * @param pre pre value
-   * @param size number of nodes to be deleted, or actually the size of the pre
+   * Deletes nodes in the specified range (p .. p + sz - 1) and updates the following pre values.
+   * @param p pre value
+   * @param s number of nodes to be deleted, or actually the size of the pre
    * value which is to be deleted
    */
-  void delete(final int pre, final int size) {
-    // find the pre value which must be deleted
-    int s = find(pre);
-    /* if the node is not directly contained as a child, either start at array
-     * index 0 or proceed with the next node in the child array to search for
-     * descendants of pre
-     */
-    if(s == -1 || children[s].pr != pre) ++s;
+  void delete(final int p, final int s) {
+    // find the node to deleted
+    int d = find(p);
+    // if the node is not directly contained as a child, either start at array index 0 or
+    // proceed with the next node in the child array to search for descendants of pre
+    if(d == -1 || nodes[d].pre != p) ++d;
     // first pre value which is not deleted
-    final int upper = pre + size;
+    final int upper = p + s;
     // number of nodes to be deleted
     int num = 0;
     // determine number of nodes to be deleted
-    for(int i = s; i < sz && children[i].pr < upper; ++i, ++num);
+    for(int i = d; i < size && nodes[i].pre < upper; ++i, ++num);
     // new size of child array
-    sz -= num;
+    size -= num;
 
     // if all nodes are deleted, just create an empty array
-    if(sz == 0) children = new NSNode[0];
-
+    if(size == 0) nodes = new NSNode[0];
     // otherwise remove nodes from the child array
-    else if(num > 0) System.arraycopy(children, s + num, children, s, sz - s);
+    else if(num > 0) System.arraycopy(nodes, d + num, nodes, d, size - d);
   }
 
-  // Printing Namespaces ======================================================
+  /**
+   * Adds the specified node into the child array, which is sorted by pre values.
+   * @param node child node
+   */
+  void add(final NSNode node) {
+    if(size == nodes.length)
+      nodes = Array.copy(nodes, new NSNode[Array.newSize(size)]);
+
+    // find inserting position
+    int s = find(node.pre);
+    if(s < 0 || node.pre != nodes[s].pre) s++;
+
+    System.arraycopy(nodes, s, nodes, s + 1, size++ - s);
+    nodes[s] = node;
+    node.parent = this;
+  }
 
   /**
-   * Prints the node structure for debugging purposes.
-   * @param ns namespace reference
-   * @param start start pre value
-   * @param end end pre value
-   * @return string
+   * Adds the specified prefix and URI reference.
+   * @param prefix prefix reference
+   * @param uri uri reference
    */
-  String print(final Namespaces ns, final int start, final int end) {
-    final TokenBuilder tb = new TokenBuilder();
-    print(tb, 0, ns, start, end);
-    return tb.toString();
+  void add(final int prefix, final int uri) {
+    final int s = values.length;
+    values = Arrays.copyOf(values, s + 2);
+    values[s] = prefix;
+    values[s + 1] = uri;
+  }
+
+  /**
+   * Recursively deletes the specified namespace URI reference.
+   * @param uri namespace URI reference
+   */
+  void delete(final int uri) {
+    for(int c = 0; c < size; ++c) nodes[c].delete(uri);
+
+    final int vl = values.length;
+    for(int v = 0; v < vl; v += 2) {
+      if(values[v + 1] != uri) continue;
+      final int[] vals = new int[vl - 2];
+      System.arraycopy(values, 0, vals, 0, v);
+      System.arraycopy(values, v + 2, vals, v, vl - v - 2);
+      values = vals;
+      break;
+    }
+  }
+
+  /**
+   * Recursive shifting of pre values after delete operations.
+   * @param start update location
+   * @param diff value to subtract from pre value
+   */
+  void decrementPre(final int start, final int diff) {
+    if(pre >= start + diff) pre -= diff;
+    for(int c = 0; c < size; c++) nodes[c].decrementPre(start, diff);
+  }
+
+  /**
+   * Increments the pre value by the specified size.
+   * @param diff value to add to pre value
+   */
+  void incrementPre(final int diff) {
+    pre += diff;
   }
 
+  // Printing Namespaces ==========================================================================
+
   /**
    * Prints the node structure for debugging purposes.
    * @param tb token builder
@@ -223,24 +286,79 @@
   private void print(final TokenBuilder tb, final int level, final Namespaces ns, final int start,
       final int end) {
 
-    if(pr >= start && pr <= end) {
+    if(pre >= start && pre <= end) {
       tb.add(NL);
       for(int i = 0; i < level; ++i) tb.add("  ");
       tb.add(toString() + ' ');
       final int[] vls = values;
       final int vl = vls.length;
       for(int i = 0; i < vl; i += 2) {
+        if(i != 0) tb.add(' ');
         tb.add("xmlns");
         final byte[] p = ns.prefix(vls[i]);
         if(p.length != 0) tb.add(':');
-        tb.add(p).add("=\"").add(ns.uri(vls[i + 1])).add("\" ");
+        tb.add(p).add("=\"").add(ns.uri(vls[i + 1])).add('"');
       }
     }
-    for(int c = 0; c < sz; ++c) children[c].print(tb, level + 1, ns, start, end);
+    for(int c = 0; c < size; ++c) nodes[c].print(tb, level + 1, ns, start, end);
+  }
+
+  /**
+   * Adds the namespace structure of a node to the specified table.
+   * @param table table
+   * @param start first pre value
+   * @param end last pre value
+   * @param ns namespace reference
+   */
+  void table(final Table table, final int start, final int end, final Namespaces ns) {
+    final int vl = values.length;
+    for(int i = 0; i < vl; i += 2) {
+      if(pre < start || pre > end) continue;
+      final TokenList tl = new TokenList();
+      tl.add(values[i + 1]);
+      tl.add(pre);
+      tl.add(pre - parent.pre);
+      tl.add(ns.prefix(values[i]));
+      tl.add(ns.uri(values[i + 1]));
+      table.contents.add(tl);
+    }
+    for(int i = 0; i < size; i++) nodes[i].table(table, start, end, ns);
+  }
+
+  /**
+   * Adds namespace information for the specified node to a map.
+   * @param map namespace map
+   * @param ns namespace reference
+   */
+  void info(final TokenObjMap<TokenList> map, final Namespaces ns) {
+    final int vl = values.length;
+    for(int v = 0; v < vl; v += 2) {
+      final byte[] pref = ns.prefix(values[v]), uri = ns.uri(values[v + 1]);
+      TokenList prfs = map.get(uri);
+      if(prfs == null) {
+        prfs = new TokenList(1);
+        map.put(uri, prfs);
+      }
+      if(!prfs.contains(pref)) prfs.add(pref);
+    }
+    for(int c = 0; c < size; ++c) nodes[c].info(map, ns);
+  }
+
+  /**
+   * Prints the node structure.
+   * @param ns namespace reference
+   * @param start start pre value
+   * @param end end pre value
+   * @return string
+   */
+  String toString(final Namespaces ns, final int start, final int end) {
+    final TokenBuilder tb = new TokenBuilder();
+    print(tb, 0, ns, start, end);
+    return tb.toString();
   }
 
   @Override
   public String toString() {
-    return "Pre[" + pr + ']';
+    return "Pre[" + pre + ']';
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/data/NSScope.java basex-8.2.3/basex-core/src/main/java/org/basex/data/NSScope.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/data/NSScope.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/data/NSScope.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,92 @@
+package org.basex.data;
+
+import java.util.*;
+
+import org.basex.util.*;
+import org.basex.util.list.*;
+
+/**
+ * This class organizes namespace scopes.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Christian Gruen
+ */
+final class NSScope {
+  /** Data reference. */
+  private final Data data;
+  /** Namespaces. */
+  private final Namespaces nspaces;
+  /** Stack with pre values. */
+  private final IntList preStack = new IntList();
+  /** Root namespace. */
+  private final NSNode root;
+  /** Tracks existing nodes. */
+  private final ArrayList<NSNode> cache;
+
+  /**
+   * Default constructor.
+   * @param pre pre value
+   * @param data data reference
+   */
+  NSScope(final int pre, final Data data) {
+    this.data = data;
+    nspaces = data.nspaces;
+    root = nspaces.cursor();
+    cache = nspaces.cache(pre);
+  }
+
+  /**
+   * Refreshes the namespace structure.
+   * @param nsPre pre value with namespaces
+   * @param c insertion counter
+   */
+  void loop(final int nsPre, final int c) {
+    if(c == 0) nspaces.root(nsPre, data);
+    while(!preStack.isEmpty() && preStack.peek() > nsPre) nspaces.close(preStack.pop());
+  }
+
+  /**
+   * Opens a new level.
+   * @param pre pre value
+   */
+  void open(final int pre) {
+    nspaces.open();
+    preStack.push(pre);
+  }
+
+  /**
+   * Parses the specified namespaces and returns all namespaces that are not declared yet.
+   * @param pre pre value
+   * @param nsp source namespaces
+   * @return {@code true} if new namespaces were added
+   */
+  boolean open(final int pre, final Atts nsp) {
+    // collect new namespaces
+    final Atts ns = new Atts();
+    final int as = nsp.size();
+    for(int a = 0; a < as; a++) {
+      final byte[] prefix = nsp.name(a), uri = nsp.value(a);
+      final int uriId = nspaces.uriIdForPrefix(prefix, true);
+      if(uriId == 0 || uriId != nspaces.uriId(uri)) ns.add(prefix, uri);
+    }
+    nspaces.open(pre, ns);
+    preStack.push(pre);
+    return !ns.isEmpty();
+  }
+
+  /**
+   * Shifts cached namespaces by the specified value.
+   * @param diff shift
+   */
+  void shift(final int diff) {
+    for(final NSNode node : cache) node.incrementPre(diff);
+  }
+
+  /**
+   * Closes the namespace scope.
+   */
+  void close() {
+    while(!preStack.isEmpty()) nspaces.close(preStack.pop());
+    nspaces.cursor(root);
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/data/Result.java basex-8.2.3/basex-core/src/main/java/org/basex/data/Result.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/data/Result.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/data/Result.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,41 +0,0 @@
-package org.basex.data;
-
-import java.io.*;
-
-import org.basex.io.serial.*;
-
-/**
- * This is an interface for query results.
- *
- * @author BaseX Team 2005-15, BSD License
- * @author Christian Gruen
- */
-public interface Result {
-  /**
-   * Number of items, stored in the result instance.
-   * @return number of items
-   */
-  long size();
-
-  /**
-   * Serializes the result, using the standard serializer.
-   * @return serialized value
-   * @throws IOException I/O exception
-   */
-  String serialize() throws IOException;
-
-  /**
-   * Serializes the result.
-   * @param ser serializer
-   * @throws IOException I/O exception
-   */
-  void serialize(Serializer ser) throws IOException;
-
-  /**
-   * Serializes the item with the specified index.
-   * @param ser serializer
-   * @param index offset of result to serialize
-   * @throws IOException I/O exception
-   */
-  void serialize(Serializer ser, int index) throws IOException;
-}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/gui/dialog/DialogColors.java basex-8.2.3/basex-core/src/main/java/org/basex/gui/dialog/DialogColors.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/gui/dialog/DialogColors.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/gui/dialog/DialogColors.java	2015-07-14 10:54:40.000000000 +0000
@@ -79,9 +79,9 @@
   public void action(final Object comp) {
     if(comp instanceof BaseXButton) {
       // reset default values
-      sliderRed.setValue(GUIOptions.COLORRED.value);
-      sliderGreen.setValue(GUIOptions.COLORGREEN.value);
-      sliderBlue.setValue(GUIOptions.COLORBLUE.value);
+      sliderRed.setValue(GUIOptions.COLORRED.value());
+      sliderGreen.setValue(GUIOptions.COLORGREEN.value());
+      sliderBlue.setValue(GUIOptions.COLORBLUE.value());
     }
     sliderRed.assign();
     sliderGreen.assign();
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/gui/dialog/DialogGeneralPrefs.java basex-8.2.3/basex-core/src/main/java/org/basex/gui/dialog/DialogGeneralPrefs.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/gui/dialog/DialogGeneralPrefs.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/gui/dialog/DialogGeneralPrefs.java	2015-07-14 10:54:40.000000000 +0000
@@ -134,7 +134,7 @@
    * @return maximum number of hits
    */
   private int hitsForSlider() {
-    int mh = gui.gopts.get(MainOptions.MAXHITS);
+    int mh = gui.gopts.get(GUIOptions.MAXRESULTS);
     if(mh == -1) mh = Integer.MAX_VALUE;
     final int hl = HITS.length - 1;
     int h = -1;
@@ -178,7 +178,7 @@
     }
     opts.set(StaticOptions.LANG, lang.getSelectedItem());
 
-    gui.gopts.set(GUIOptions.MAXHITS, HITS[limit.getValue()]);
+    gui.gopts.set(GUIOptions.MAXRESULTS, HITS[limit.getValue()]);
 
     creds.setText(TRANSLATION + COLS + creds(lang.getSelectedItem()));
     final int mh = HITS[limit.getValue()];
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/gui/dialog/DialogMem.java basex-8.2.3/basex-core/src/main/java/org/basex/gui/dialog/DialogMem.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/gui/dialog/DialogMem.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/gui/dialog/DialogMem.java	2015-07-14 10:54:40.000000000 +0000
@@ -69,8 +69,7 @@
     if(vis) return;
 
     // regularly refresh panel
-    final Timer timer = new Timer(true);
-    timer.scheduleAtFixedRate(new TimerTask() {
+    new Timer(true).scheduleAtFixedRate(new TimerTask() {
       @Override
       public void run() {
         if(isVisible() && !text.selected()) text.setText(info());
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/gui/dialog/DialogProps.java basex-8.2.3/basex-core/src/main/java/org/basex/gui/dialog/DialogProps.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/gui/dialog/DialogProps.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/gui/dialog/DialogProps.java	2015-07-14 10:54:40.000000000 +0000
@@ -125,7 +125,7 @@
 
     final String db = InfoDB.db(data.meta, true, false, true);
     final TokenBuilder info = new TokenBuilder(db);
-    if(data.nspaces.size() != 0) {
+    if(!data.nspaces.isEmpty()) {
       info.bold().add(NL + NAMESPACES + NL).norm().add(data.nspaces.info());
     }
 
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/gui/GUI.java basex-8.2.3/basex-core/src/main/java/org/basex/gui/GUI.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/gui/GUI.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/gui/GUI.java	2015-07-14 10:54:40.000000000 +0000
@@ -29,6 +29,8 @@
 import org.basex.io.*;
 import org.basex.io.out.*;
 import org.basex.query.*;
+import org.basex.query.value.*;
+import org.basex.query.value.seq.*;
 import org.basex.util.*;
 import org.basex.util.options.*;
 
@@ -377,10 +379,10 @@
     // check and add default namespace
     final Data data = context.data();
     final Namespaces ns = data.nspaces;
-    String in = qu.trim().isEmpty() ? "()" : qu;
-    final int u = ns.uri(Token.EMPTY, 0, data);
-    if(u != 0) in = Util.info("declare default element namespace \"%\"; %", ns.uri(u), in);
-    execute(edit, new XQuery(in));
+    String q = qu.trim().isEmpty() ? "()" : qu;
+    final int uriId = ns.uriIdForPrefix(Token.EMPTY, 0, data);
+    if(uriId != 0) q = Util.info("declare default element namespace \"%\"; %", ns.uri(uriId), q);
+    execute(edit, new XQuery(q));
   }
 
   /**
@@ -449,6 +451,10 @@
       // execute command and cache result
       final ArrayOutput ao = new ArrayOutput();
       ao.setLimit(gopts.get(GUIOptions.MAXTEXT));
+      // sets the maximum number of hits
+      cmd.maxResults(gopts.get(GUIOptions.MAXRESULTS));
+
+      // checks if the command is updating
       updating = cmd.updating(context);
 
       // updates the query editor
@@ -491,7 +497,7 @@
         }
       } else {
         // get query result
-        final Result result = cmd.finish();
+        final Value result = cmd.finish();
         DBNodes nodes = result instanceof DBNodes && result.size() != 0 ? (DBNodes) result : null;
 
         final boolean updated = cmd.updated(context);
@@ -507,7 +513,7 @@
           // check if result has changed
           final boolean flt = gopts.get(GUIOptions.FILTERRT);
           final DBNodes curr = context.current();
-          if(flt || curr != null && !curr.equals(current)) {
+          if(flt || curr != null && !curr.sameAs(current)) {
             // refresh context if at least one node was found
             if(nodes != null) notify.context(nodes, flt, null);
           } else if(context.marked != null) {
@@ -674,7 +680,7 @@
    * @param n number of results
    */
   private void setResults(final long n) {
-    int mh = context.options.get(MainOptions.MAXHITS);
+    int mh = gopts.get(GUIOptions.MAXRESULTS);
     if(mh < 0) mh = Integer.MAX_VALUE;
     hits.setText(Util.info(RESULTS_X, (n >= mh ? "\u2265" : "") + n));
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/gui/GUIMenuCmd.java basex-8.2.3/basex-core/src/main/java/org/basex/gui/GUIMenuCmd.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/gui/GUIMenuCmd.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/gui/GUIMenuCmd.java	2015-07-14 10:54:40.000000000 +0000
@@ -15,6 +15,7 @@
 import org.basex.query.func.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.node.*;
+import org.basex.query.value.seq.*;
 import org.basex.query.value.type.*;
 import org.basex.util.*;
 import org.basex.util.list.*;
@@ -240,7 +241,7 @@
   C_COPYPATH(COPY_PATH, "% shift C", true, false) {
     @Override
     public void execute(final GUI gui) {
-      final int pre = gui.context.marked.pres[0];
+      final int pre = gui.context.marked.pre(0);
       BaseXLayout.copy(Token.string(ViewData.path(gui.context.data(), pre)));
     }
 
@@ -258,7 +259,7 @@
     public void execute(final GUI gui) {
       final Context ctx = gui.context;
       final DBNodes n = ctx.marked;
-      ctx.copied = new DBNodes(n.data, n.pres);
+      ctx.copied = new DBNodes(n.data(), n.pres());
     }
 
     @Override
@@ -304,7 +305,7 @@
         if(i > 0) sb.append(',');
         sb.append(openPre(n, i));
       }
-      gui.context.marked = new DBNodes(n.data);
+      gui.context.marked = new DBNodes(n.data());
       gui.context.copied = null;
       gui.context.focused = -1;
       gui.execute(new XQuery("delete nodes (" + sb + ')'));
@@ -350,7 +351,7 @@
     @Override
     public void execute(final GUI gui) {
       final DBNodes n = gui.context.marked;
-      final DialogEdit edit = new DialogEdit(gui, n.pres[0]);
+      final DialogEdit edit = new DialogEdit(gui, n.pre(0));
       if(!edit.ok()) return;
 
       String rename = null;
@@ -784,7 +785,7 @@
       // check if all nodes are document nodes
       boolean doc = true;
       final Data data = ctx.data();
-      for(final int pre : ctx.current().pres) doc &= data.kind(pre) == Data.DOC;
+      for(final int pre : ctx.current().pres()) doc &= data.kind(pre) == Data.DOC;
       final DBNodes nodes;
       if(doc) {
         // if yes, jump to database root
@@ -793,7 +794,7 @@
       } else {
         // otherwise, jump to parent nodes
         final IntList pres = new IntList();
-        for(final int pre : ctx.current().pres) {
+        for(final int pre : ctx.current().pres()) {
           final int k = data.kind(pre);
           pres.add(k == Data.DOC ? pre : data.parent(pre, k));
         }
@@ -894,7 +895,7 @@
    */
   private static boolean updatable(final DBNodes n, final int... no) {
     if(n == null || (no.length == 0 ? n.size() < 1 : n.size() != 1)) return false;
-    final int k = n.data.kind(n.pres[0]);
+    final int k = n.data().kind(n.pre(0));
     for(final int i : no) if(k == i) return false;
     return true;
   }
@@ -915,7 +916,7 @@
    * @return function string
    */
   private static String openPre(final DBNodes n, final int i) {
-    return Function._DB_OPEN_PRE.get(null, null, Str.get(n.data.meta.name),
-        Int.get(n.pres[i])).toString();
+    return Function._DB_OPEN_PRE.get(null, null, Str.get(n.data().meta.name),
+        Int.get(n.pre(i))).toString();
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/gui/GUIOptions.java basex-8.2.3/basex-core/src/main/java/org/basex/gui/GUIOptions.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/gui/GUIOptions.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/gui/GUIOptions.java	2015-07-14 10:54:40.000000000 +0000
@@ -189,7 +189,7 @@
   /** Maximum text size to be displayed. */
   public static final NumberOption MAXTEXT = new NumberOption("MAXTEXT", 1 << 21);
   /** Maximum number of hits to be displayed (-1: return all hits; default: 250K). */
-  public static final NumberOption MAXHITS = new NumberOption("MAXHITS", 250000);
+  public static final NumberOption MAXRESULTS = new NumberOption("MAXHITS", 250000);
 
   /** Comment: written to options file. */
   public static final Comment C_SEARCH = new Comment("Search");
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/gui/layout/BaseXMem.java basex-8.2.3/basex-core/src/main/java/org/basex/gui/layout/BaseXMem.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/gui/layout/BaseXMem.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/gui/layout/BaseXMem.java	2015-07-14 10:54:40.000000000 +0000
@@ -35,8 +35,7 @@
     }
 
     // regularly refresh panel
-    final Timer timer = new Timer(true);
-    timer.scheduleAtFixedRate(new TimerTask() {
+    new Timer(true).scheduleAtFixedRate(new TimerTask() {
       @Override
       public void run() { repaint(); }
     }, 0, 5000);
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/gui/layout/BaseXScrollBar.java basex-8.2.3/basex-core/src/main/java/org/basex/gui/layout/BaseXScrollBar.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/gui/layout/BaseXScrollBar.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/gui/layout/BaseXScrollBar.java	2015-07-14 10:54:40.000000000 +0000
@@ -183,7 +183,7 @@
     // start dragging
     if(sliding || animated) return;
 
-    new Thread() {
+    final Thread t = new Thread() {
       @Override
       public void run() {
         // scroll up/down/move slider
@@ -207,7 +207,9 @@
           }
         }
       }
-    }.start();
+    };
+    t.setDaemon(true);
+    t.start();
   }
 
   @Override
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/gui/text/TextEditor.java basex-8.2.3/basex-core/src/main/java/org/basex/gui/text/TextEditor.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/gui/text/TextEditor.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/gui/text/TextEditor.java	2015-07-14 10:54:40.000000000 +0000
@@ -418,16 +418,25 @@
     final byte[] ste = concat(st, SPACE), ene = concat(SPACE, en);
     final int sl = st.length, el = en.length, sle = ste.length, ele = ene.length;
 
-    // no selection: select line
     if(!selected()) {
+      // no selection: select line
       start = pos;
       end = pos;
       while(start > 0 && text[start - 1] != '\n') --start;
       while(end < size() && text[end] != '\n') ++end;
+    } else if(start > end) {
+      // selection -> start < end
+      final int s = start;
+      start = end;
+      end = s;
     }
 
-    final int min = Math.min(start, end);
-    int max = Math.max(start, end);
+    // ignore whitespaces
+    while(start < end && ws(text[start])) ++start;
+    while(end > start && ws(text[end - 1])) --end;
+
+    final int min = start;
+    int max = end;
     if(selected() && text[max - 1] == '\n') max--;
 
     // create new text with or without comment
@@ -689,14 +698,14 @@
       } else if(ch == '~') {
         // closes XQuery comments
         if(prev == ':' && pprv == '(') {
-          sb.append("\n : \n ");
+          sb.append("  ");
           if(curr != ':') {
             sb.append(':');
             if(curr != ')') sb.append(')');
           } else if(next != ')') {
             sb.append(')');
           }
-          move = 5;
+          move = 2;
         }
       } else if(ch == '-') {
         // closes XML comments
@@ -737,20 +746,19 @@
    * @param sb string builder
    */
   private void closeElem(final StringBuilder sb) {
-    int p = pos - 1;
-    for(; p >= 0; p--) {
-      final byte b = text[p];
-      if(!XMLToken.isNCChar(b) && b != ':') {
-        if(b == '<' && p < pos - 1) {
+    final int p = pos;
+    while(pos > 0) {
+      final int cp = prev();
+      if(!XMLToken.isNCChar(cp) && cp != ':') {
+        if(cp == '<' && pos < p - 1) {
           // add closing element
-          sb.append("</");
-          while(++p < pos) sb.append((char) text[p]);
-          sb.append('>');
-          break;
+          next();
+          sb.append("</").append(new TokenBuilder().add(text, pos, p).toString()).append('>');
         }
-        return;
+        break;
       }
     }
+    pos = p;
   }
 
   /**
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/gui/view/explore/ExploreView.java basex-8.2.3/basex-core/src/main/java/org/basex/gui/view/explore/ExploreView.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/gui/view/explore/ExploreView.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/gui/view/explore/ExploreView.java	2015-07-14 10:54:40.000000000 +0000
@@ -8,10 +8,10 @@
 
 import javax.swing.*;
 
-import org.basex.data.*;
 import org.basex.gui.*;
 import org.basex.gui.layout.*;
 import org.basex.gui.view.*;
+import org.basex.query.value.seq.*;
 
 /**
  * This view allows the input of database queries.
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/gui/view/folder/FolderIterator.java basex-8.2.3/basex-core/src/main/java/org/basex/gui/view/folder/FolderIterator.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/gui/view/folder/FolderIterator.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/gui/view/folder/FolderIterator.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,6 +1,7 @@
 package org.basex.gui.view.folder;
 
 import org.basex.data.*;
+import org.basex.query.value.seq.*;
 import org.basex.util.list.*;
 
 /**
@@ -94,7 +95,7 @@
   private boolean moreCS() {
     final DBNodes current = view.gui.context.current();
     if(current == null || ++cp >= current.size()) return false;
-    par = current.pres[cp];
+    par = current.pre(cp);
     pre = par;
     level = 0;
     ll = 0;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/gui/view/folder/FolderView.java basex-8.2.3/basex-core/src/main/java/org/basex/gui/view/folder/FolderView.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/gui/view/folder/FolderView.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/gui/view/folder/FolderView.java	2015-07-14 10:54:40.000000000 +0000
@@ -14,6 +14,7 @@
 import org.basex.gui.*;
 import org.basex.gui.layout.*;
 import org.basex.gui.view.*;
+import org.basex.query.value.seq.*;
 
 /**
  * This view offers a folder visualization of the database contents.
@@ -113,7 +114,7 @@
     scroll.pos(0);
 
     final DBNodes curr = gui.context.current();
-    if(more && curr.size() != 0) jumpTo(curr.pres[0], true);
+    if(more && curr.size() != 0) jumpTo(curr.pre(0), true);
     refreshHeight();
     repaint();
   }
@@ -141,7 +142,7 @@
     scroll.pos(0);
 
     final DBNodes marked = gui.context.marked;
-    if(marked.size() != 0) jumpTo(marked.pres[0], true);
+    if(marked.size() != 0) jumpTo(marked.pre(0), true);
     refreshHeight();
     repaint();
   }
@@ -461,11 +462,11 @@
     // calculate new tree position
     gui.context.focused = -1;
     final DBNodes curr = gui.context.current();
-    int pre = curr.pres[0];
+    int pre = curr.pre(0);
     final FolderIterator it = new FolderIterator(this);
     while(it.more() && focus-- != 0) pre = it.pre;
 
-    if(pre == curr.pres[0] && down) ++pre;
+    if(pre == curr.pre(0) && down) ++pre;
     gui.notify.focus(pre, this);
     jumpTo(pre, false);
     repaint();
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/gui/view/map/MapDefault.java basex-8.2.3/basex-core/src/main/java/org/basex/gui/view/map/MapDefault.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/gui/view/map/MapDefault.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/gui/view/map/MapDefault.java	2015-07-14 10:54:40.000000000 +0000
@@ -6,6 +6,7 @@
 import org.basex.gui.*;
 import org.basex.gui.layout.*;
 import org.basex.gui.view.*;
+import org.basex.query.util.ft.*;
 
 /**
  * Adds default paint operations to TreeMap.
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/gui/view/map/MapPainter.java basex-8.2.3/basex-core/src/main/java/org/basex/gui/view/map/MapPainter.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/gui/view/map/MapPainter.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/gui/view/map/MapPainter.java	2015-07-14 10:54:40.000000000 +0000
@@ -5,6 +5,7 @@
 import org.basex.data.*;
 import org.basex.gui.*;
 import org.basex.gui.view.*;
+import org.basex.query.value.seq.*;
 
 /**
  * Provides an interface for data specific TreeMap visualizations.
@@ -20,12 +21,12 @@
 
   /**
    * Constructor.
-   * @param m map reference
-   * @param opts gui options
+   * @param map map reference
+   * @param gopts gui options
    */
-  MapPainter(final MapView m, final GUIOptions opts) {
-    view = m;
-    gopts = opts;
+  MapPainter(final MapView map, final GUIOptions gopts) {
+    this.view = map;
+    this.gopts = gopts;
   }
 
   /**
@@ -42,7 +43,7 @@
       if(p >= 0) {
         // mark ancestor of invisible node;
         final int i = rects.find(rects.get(ri));
-        return p < marked.size() && i + 1 < rects.size && marked.sorted[p] <
+        return p < marked.size() && i + 1 < rects.size && marked.sorted(p) <
           rects.sorted[i + 1].pre ? GUIConstants.colormark2 : null;
       }
     }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/gui/view/map/MapRect.java basex-8.2.3/basex-core/src/main/java/org/basex/gui/view/map/MapRect.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/gui/view/map/MapRect.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/gui/view/map/MapRect.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,7 +1,7 @@
 package org.basex.gui.view.map;
 
-import org.basex.data.*;
 import org.basex.gui.view.*;
+import org.basex.query.util.ft.*;
 
 /**
  * View rectangle.
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/gui/view/map/MapRenderer.java basex-8.2.3/basex-core/src/main/java/org/basex/gui/view/map/MapRenderer.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/gui/view/map/MapRenderer.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/gui/view/map/MapRenderer.java	2015-07-14 10:54:40.000000000 +0000
@@ -8,8 +8,8 @@
 import java.util.*;
 
 import org.basex.core.*;
-import org.basex.data.*;
 import org.basex.gui.layout.*;
+import org.basex.query.util.ft.*;
 import org.basex.util.ft.*;
 import org.basex.util.list.*;
 
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/gui/view/map/MapView.java basex-8.2.3/basex-core/src/main/java/org/basex/gui/view/map/MapView.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/gui/view/map/MapView.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/gui/view/map/MapView.java	2015-07-14 10:54:40.000000000 +0000
@@ -14,6 +14,7 @@
 import org.basex.gui.*;
 import org.basex.gui.layout.*;
 import org.basex.gui.view.*;
+import org.basex.query.value.seq.*;
 import org.basex.util.*;
 import org.basex.util.ft.*;
 import org.basex.util.list.*;
@@ -140,7 +141,7 @@
     final int hist = gui.notify.hist;
     final boolean page = !more && rectHist[hist + 1] != null &&
       rectHist[hist + 1].pre == 0 || more && (context.size() != 1 ||
-      focused == null || context.pres[0] != focused.pre);
+      focused == null || context.pre(0) != focused.pre);
     if(page) focused = new MapRect(0, 0, getWidth(), 1);
 
     zoom(more, quick);
@@ -217,7 +218,9 @@
       repaint();
     } else {
       zoomStep = ZOOMSIZE;
-      new Thread(this).start();
+      final Thread t = new Thread(this);
+      t.setDaemon(true);
+      t.start();
     }
   }
 
@@ -280,8 +283,8 @@
     gui.cursor(CURSORWAIT);
 
     initLen();
-    layout = new MapLayout(nodes.data, textLen, gui.gopts);
-    layout.makeMap(rect, new MapList(nodes.pres.clone()), 0, (int) nodes.size() - 1);
+    layout = new MapLayout(nodes.data(), textLen, gui.gopts);
+    layout.makeMap(rect, new MapList(nodes.pres().clone()), 0, (int) nodes.size() - 1);
     // rectangles are copied to avoid synchronization issues
     mainRects = layout.rectangles.copy();
 
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/gui/view/plot/PlotAxis.java basex-8.2.3/basex-core/src/main/java/org/basex/gui/view/plot/PlotAxis.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/gui/view/plot/PlotAxis.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/gui/view/plot/PlotAxis.java	2015-07-14 10:54:40.000000000 +0000
@@ -251,7 +251,7 @@
     for(int p = pre; p < limit; ++p) {
       final int kind = data.kind(p);
       if((kind == Data.ELEM && elem || kind == Data.ATTR && !elem) &&
-          attrID == data.name(p)) return data.atom(p);
+          attrID == data.nameId(p)) return data.atom(p);
     }
     return EMPTY;
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/gui/view/plot/PlotData.java basex-8.2.3/basex-core/src/main/java/org/basex/gui/view/plot/PlotData.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/gui/view/plot/PlotData.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/gui/view/plot/PlotData.java	2015-07-14 10:54:40.000000000 +0000
@@ -8,6 +8,7 @@
 import org.basex.data.*;
 import org.basex.index.name.*;
 import org.basex.index.stats.*;
+import org.basex.query.value.seq.*;
 import org.basex.util.list.*;
 
 /**
@@ -96,19 +97,19 @@
     final int itmID = data.elemNames.id(item);
 
     if(!sub) {
-      pres = nodes.pres;
+      pres = nodes.pres();
       Arrays.sort(pres);
       return;
     }
 
-    final int[] contextPres = nodes.pres;
+    final int[] contextPres = nodes.pres();
     for(int p : contextPres) {
       if(p >= data.meta.size) break;
       final int nl = p + data.size(p, Data.ELEM);
       while(p < nl) {
         final int kind = data.kind(p);
         if(kind == Data.ELEM) {
-          if(data.name(p) == itmID) il.add(p);
+          if(data.nameId(p) == itmID) il.add(p);
           p += data.attSize(p, Data.ELEM);
         } else {
           ++p;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/gui/view/plot/PlotView.java basex-8.2.3/basex-core/src/main/java/org/basex/gui/view/plot/PlotView.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/gui/view/plot/PlotView.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/gui/view/plot/PlotView.java	2015-07-14 10:54:40.000000000 +0000
@@ -16,6 +16,7 @@
 import org.basex.gui.layout.*;
 import org.basex.gui.view.*;
 import org.basex.index.stats.*;
+import org.basex.query.value.seq.*;
 import org.basex.util.list.*;
 
 /**
@@ -300,12 +301,12 @@
     if(focused != -1) {
       final int itmID = data.elemNames.id(plotData.item);
       int k = data.kind(focused);
-      int name = data.name(focused);
+      int name = data.nameId(focused);
       while(focused > 0 && itmID != name) {
         focused = data.parent(focused, k);
         if(focused > -1) {
           k = data.kind(focused);
-          name = data.name(focused);
+          name = data.nameId(focused);
         }
       }
     }
@@ -385,7 +386,8 @@
 
     final DBNodes marked = gui.context.marked;
     if(marked.size() == 0) return;
-    final int[] m = Arrays.copyOf(marked.pres, marked.pres.length);
+    final int[] pres = marked.pres();
+    final int[] m = Arrays.copyOf(pres, pres.length);
     int i = 0;
 
     // no child nodes of the marked context nodes are marked
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/gui/view/table/TableContent.java basex-8.2.3/basex-core/src/main/java/org/basex/gui/view/table/TableContent.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/gui/view/table/TableContent.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/gui/view/table/TableContent.java	2015-07-14 10:54:40.000000000 +0000
@@ -9,6 +9,7 @@
 import org.basex.data.*;
 import org.basex.gui.*;
 import org.basex.gui.layout.*;
+import org.basex.query.value.seq.*;
 import org.basex.util.*;
 
 /**
@@ -81,7 +82,7 @@
 
       final int pre = tdata.rows.get(l);
       final long ms = marked.size();
-      while(mpos < ms && marked.pres[mpos] < pre) ++mpos;
+      while(mpos < ms && marked.pre(mpos) < pre) ++mpos;
 
       // draw line
       g.setColor(GUIConstants.color2);
@@ -90,7 +91,7 @@
       g.drawLine(0, posY + rowH, w, posY + rowH);
 
       // verify if current node is marked or focused
-      final boolean rm = mpos < marked.size() && marked.pres[mpos] == pre;
+      final boolean rm = mpos < marked.size() && marked.pre(mpos) == pre;
       final boolean rf = pre == rfocus;
       final int col = rm ? rf ? 5 : 4 : 3;
       if(rm || rf) {
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/gui/view/table/TableData.java basex-8.2.3/basex-core/src/main/java/org/basex/gui/view/table/TableData.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/gui/view/table/TableData.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/gui/view/table/TableData.java	2015-07-14 10:54:40.000000000 +0000
@@ -164,19 +164,19 @@
   private void createRows() {
     final Data data = ctx.data();
     rows = new IntList();
-    for(int p : ctx.current().pres) {
-      if(p >= data.meta.size) break;
-      final int s = p + data.size(p, data.kind(p));
+    for(int pre : ctx.current().pres()) {
+      if(pre >= data.meta.size) break;
+      final int s = pre + data.size(pre, data.kind(pre));
       // find first root element name
       do {
-        if(data.kind(p) == Data.ELEM && data.name(p) == root) break;
-      } while(++p < s);
+        if(data.kind(pre) == Data.ELEM && data.nameId(pre) == root) break;
+      } while(++pre < s);
 
       // parse whole document and collect root element names
-      while(p < s) {
-        final int k = data.kind(p);
-        if(k == Data.ELEM && data.name(p) == root) rows.add(p);
-        p += data.attSize(p, k);
+      while(pre < s) {
+        final int k = data.kind(pre);
+        if(k == Data.ELEM && data.nameId(pre) == root) rows.add(pre);
+        pre += data.attSize(pre, k);
       }
     }
     sort();
@@ -253,7 +253,7 @@
       final int s = p + data.size(p, data.kind(p));
       while(p != s) {
         final int k = data.kind(p);
-        if((e && k == Data.ELEM || !e && k == Data.ATTR) && data.name(p) == c) {
+        if((e && k == Data.ELEM || !e && k == Data.ATTR) && data.nameId(p) == c) {
           tokens[r] = data.atom(p);
           break;
         }
@@ -276,7 +276,7 @@
     if(pre == -1) return -1;
     int p = pre;
     int k = data.kind(p);
-    while(p != -1 && (k != Data.ELEM || data.name(p) != root)) {
+    while(p != -1 && (k != Data.ELEM || data.nameId(p) != root)) {
       p = data.parent(p, k);
       k = p == -1 ? 0 : data.kind(p);
     }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/gui/view/table/TableHeader.java basex-8.2.3/basex-core/src/main/java/org/basex/gui/view/table/TableHeader.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/gui/view/table/TableHeader.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/gui/view/table/TableHeader.java	2015-07-14 10:54:40.000000000 +0000
@@ -14,6 +14,7 @@
 import org.basex.gui.*;
 import org.basex.gui.layout.*;
 import org.basex.gui.view.table.TableData.TableCol;
+import org.basex.query.value.seq.*;
 
 /**
  * This is the header of the table view.
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/gui/view/table/TableIterator.java basex-8.2.3/basex-core/src/main/java/org/basex/gui/view/table/TableIterator.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/gui/view/table/TableIterator.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/gui/view/table/TableIterator.java	2015-07-14 10:54:40.000000000 +0000
@@ -44,7 +44,7 @@
    */
   void init(final int p) {
     last = p + data.size(p, data.kind(p));
-    rootElem = data.name(p);
+    rootElem = data.nameId(p);
     pre = p;
     elem = -1;
   }
@@ -60,7 +60,7 @@
 
       // content found...
       if(text || k == Data.ATTR) {
-        final int id = text ? elem : data.name(pre);
+        final int id = text ? elem : data.nameId(pre);
         // find correct column...
         final TableCol[] cols = tdata.cols;
         final int cl = cols.length;
@@ -69,7 +69,7 @@
         }
       } else if(k == Data.ELEM) {
         // remember name of last element
-        elem = data.name(pre);
+        elem = data.nameId(pre);
         if(elem == rootElem) return false;
       }
     }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/gui/view/table/TableView.java basex-8.2.3/basex-core/src/main/java/org/basex/gui/view/table/TableView.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/gui/view/table/TableView.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/gui/view/table/TableView.java	2015-07-14 10:54:40.000000000 +0000
@@ -13,6 +13,7 @@
 import org.basex.gui.*;
 import org.basex.gui.layout.*;
 import org.basex.gui.view.*;
+import org.basex.query.value.seq.*;
 import org.basex.util.*;
 import org.basex.util.list.*;
 
@@ -79,7 +80,9 @@
     } else {
       if(!more) tdata.resetFilter();
       gui.updating = true;
-      new Thread(this).start();
+      final Thread t = new Thread(this);
+      t.setDaemon(true);
+      t.start();
     }
   }
 
@@ -96,7 +99,7 @@
     final Context context = gui.context;
     final DBNodes marked = context.marked;
     if(marked.size() != 0) {
-      final int p = tdata.getRoot(context.data(), marked.pres[0]);
+      final int p = tdata.getRoot(context.data(), marked.pre(0));
       if(p != -1) setPos(p);
     }
     repaint();
@@ -250,7 +253,7 @@
       } else {
         DBNodes nodes = context.marked;
         if(getCursor() == CURSORARROW) {
-          nodes = new DBNodes(nodes.data, tdata.getRoot(nodes.data, pre));
+          nodes = new DBNodes(nodes.data(), tdata.getRoot(nodes.data(), pre));
         }
         gui.notify.context(nodes, false, null);
       }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/gui/view/text/TextView.java basex-8.2.3/basex-core/src/main/java/org/basex/gui/view/text/TextView.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/gui/view/text/TextView.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/gui/view/text/TextView.java	2015-07-14 10:54:40.000000000 +0000
@@ -12,7 +12,6 @@
 
 import org.basex.core.*;
 import org.basex.core.parse.*;
-import org.basex.data.*;
 import org.basex.gui.*;
 import org.basex.gui.layout.*;
 import org.basex.gui.layout.BaseXFileChooser.Mode;
@@ -22,6 +21,8 @@
 import org.basex.io.out.*;
 import org.basex.io.serial.*;
 import org.basex.query.*;
+import org.basex.query.value.*;
+import org.basex.query.value.seq.*;
 import org.basex.util.*;
 
 /**
@@ -158,27 +159,27 @@
   /**
    * Caches the output.
    * @param out cached output
-   * @param c command
-   * @param r result
+   * @param command command
+   * @param result result
    * @throws QueryException query exception
    */
-  public void cache(final ArrayOutput out, final Command c, final Result r)
+  public void cache(final ArrayOutput out, final Command command, final Value result)
       throws QueryException {
 
     // cache command or node set
     cmd = null;
     ns = null;
 
-    final int mh = gui.context.options.get(MainOptions.MAXHITS);
+    final int mh = gui.gopts.get(GUIOptions.MAXRESULTS);
     boolean parse = false;
-    if(mh >= 0 && r != null && r.size() >= mh) {
+    if(mh >= 0 && result != null && result.size() >= mh) {
       parse = true;
     } else if(out.finished()) {
-      if(r instanceof DBNodes) ns = (DBNodes) r;
+      if(result instanceof DBNodes) ns = (DBNodes) result;
       else parse = true;
     }
     // create new command instance
-    if(parse) cmd = new CommandParser(c.toString(), gui.context).parseSingle();
+    if(parse) cmd = new CommandParser(command.toString(), gui.context).parseSingle();
   }
 
   /**
@@ -209,11 +210,6 @@
     gui.gopts.set(GUIOptions.WORKPATH, file.path());
 
     gui.cursor(CURSORWAIT, true);
-    final MainOptions opts = gui.context.options;
-    final int mh = opts.get(MainOptions.MAXHITS);
-    opts.set(MainOptions.MAXHITS, -1);
-    opts.set(MainOptions.CACHEQUERY, false);
-
     try(final PrintOutput out = new PrintOutput(file.toString())) {
       if(cmd != null) {
         cmd.execute(gui.context, out);
@@ -225,8 +221,6 @@
     } catch(final IOException ex) {
       BaseXDialog.error(gui, Util.info(FILE_NOT_SAVED_X, file));
     } finally {
-      opts.set(MainOptions.MAXHITS, mh);
-      opts.set(MainOptions.CACHEQUERY, true);
       gui.cursor(CURSORARROW, true);
     }
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/gui/view/tree/TreeRects.java basex-8.2.3/basex-core/src/main/java/org/basex/gui/view/tree/TreeRects.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/gui/view/tree/TreeRects.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/gui/view/tree/TreeRects.java	2015-07-14 10:54:40.000000000 +0000
@@ -2,9 +2,9 @@
 
 import java.awt.*;
 
-import org.basex.data.*;
 import org.basex.gui.layout.*;
 import org.basex.gui.view.*;
+import org.basex.query.value.seq.*;
 
 /**
  * This class stores the rectangles.
@@ -40,7 +40,7 @@
   double generateRects(final TreeSubtree sub, final Graphics g, final int ds, final int dw,
       final boolean slim) {
 
-    final int[] roots = nodes.pres;
+    final int[] roots = nodes.pres();
     final int rl = roots.length;
     if(rl == 0) return 0;
     final double w = (dw - BORDER_PADDING - ds) / (double) rl;
@@ -155,7 +155,7 @@
    * @return text
    */
   byte[] getText(final int pre) {
-    return ViewData.name(view.gui.gopts, nodes.data, pre);
+    return ViewData.name(view.gui.gopts, nodes.data(), pre);
   }
 
   /**
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/gui/view/tree/TreeView.java basex-8.2.3/basex-core/src/main/java/org/basex/gui/view/tree/TreeView.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/gui/view/tree/TreeView.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/gui/view/tree/TreeView.java	2015-07-14 10:54:40.000000000 +0000
@@ -15,6 +15,7 @@
 import org.basex.gui.*;
 import org.basex.gui.layout.*;
 import org.basex.gui.view.*;
+import org.basex.query.value.seq.*;
 import org.basex.util.*;
 import org.basex.util.list.*;
 
@@ -161,7 +162,7 @@
     gui.painting = true;
 
     final DBNodes nodes = gui.context.current();
-    roots = nodes.pres;
+    roots = nodes.pres();
     final int rl = roots.length;
     if(rl == 0) return;
 
@@ -547,15 +548,15 @@
     BaseXLayout.antiAlias(mg);
     mg.setFont(font);
 
-    final int[] mark = gui.context.marked.pres;
-    if(mark.length == 0) return;
+    final int[] marked = gui.context.marked.pres();
+    if(marked.length == 0) return;
 
     int rn = 0;
     final int rl = roots.length;
     while(rn < rl) {
-      final int ml = mark.length;
+      final int ml = marked.length;
       final LinkedList<Integer> marklink = new LinkedList<>();
-      for(int m = 0; m < ml; ++m) marklink.add(m, mark[m]);
+      for(int m = 0; m < ml; ++m) marklink.add(m, marked[m]);
 
       for(int lv = 0; lv < sub.subtreeHeight(rn); ++lv) {
         final int y = getYperLevel(lv);
@@ -570,8 +571,7 @@
 
             if(ix > -1) {
               li.remove();
-              final int x = (int) (rect.w * ix / (double) sub.levelSize(rn,
-                  lv));
+              final int x = (int) (rect.w * ix / (double) sub.levelSize(rn, lv));
               mg.setColor(colormark1);
               mg.fillRect(rect.x + x, y, 2, nodeHeight + 1);
             }
@@ -579,9 +579,7 @@
         } else {
           while(li.hasNext()) {
             final int pre = li.next();
-
             final TreeRect rect = tr.searchRect(sub, rn, lv, pre);
-
             if(rect != null) {
               li.remove();
               drawRectangle(mg, rn, lv, rect, pre, Draw.MARK);
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/gui/view/ViewNotifier.java basex-8.2.3/basex-core/src/main/java/org/basex/gui/view/ViewNotifier.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/gui/view/ViewNotifier.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/gui/view/ViewNotifier.java	2015-07-14 10:54:40.000000000 +0000
@@ -8,6 +8,7 @@
 import org.basex.data.*;
 import org.basex.gui.*;
 import org.basex.gui.layout.*;
+import org.basex.query.value.seq.*;
 import org.basex.util.*;
 
 /**
@@ -169,10 +170,10 @@
 
     // add new entry if current node set has not been cached yet
     final DBNodes newn = nodes.discardDocs();
-    final DBNodes empty = new DBNodes(ctx.data(), ctx.marked.ftpos());
+    final DBNodes empty = new DBNodes(ctx.data()).ftpos(ctx.marked.ftpos());
     final DBNodes curr = quick ? ctx.current() : null;
     final DBNodes cmp = quick ? curr : ctx.marked;
-    if(cont[hist] == null ? cmp != null : cmp == null || !cont[hist].equals(cmp)) {
+    if(cont[hist] == null ? cmp != null : cmp == null || !cont[hist].sameAs(cmp)) {
       checkHist();
       if(quick) {
         // store history entry
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/index/ft/FTIndex.java basex-8.2.3/basex-core/src/main/java/org/basex/index/ft/FTIndex.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/index/ft/FTIndex.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/index/ft/FTIndex.java	2015-07-14 10:54:40.000000000 +0000
@@ -12,8 +12,10 @@
 import org.basex.index.*;
 import org.basex.index.query.*;
 import org.basex.index.stats.*;
+import org.basex.index.value.*;
 import org.basex.io.random.*;
 import org.basex.query.expr.ft.*;
+import org.basex.query.util.ft.*;
 import org.basex.util.*;
 import org.basex.util.ft.*;
 import org.basex.util.hash.*;
@@ -46,7 +48,7 @@
  * @author BaseX Team 2005-15, BSD License
  * @author Christian Gruen
  */
-public final class FTIndex implements Index {
+public final class FTIndex implements ValueIndex {
   /** Entry size. */
   private static final int ENTRY = 9;
 
@@ -103,9 +105,6 @@
   }
 
   @Override
-  public synchronized void init() { }
-
-  @Override
   public synchronized int costs(final IndexToken it) {
     final byte[] tok = it.get();
     if(tok.length > data.meta.maxlen) return Integer.MAX_VALUE;
@@ -478,4 +477,16 @@
       pos = ps;
     }
   }
+
+  @Override
+  public void add(final TokenObjMap<IntList> map) { }
+
+  @Override
+  public void delete(final TokenObjMap<IntList> map) { }
+
+  @Override
+  public void replace(final byte[] old, final byte[] key, final int id) { }
+
+  @Override
+  public void flush() { }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/index/IndexBuilder.java basex-8.2.3/basex-core/src/main/java/org/basex/index/IndexBuilder.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/index/IndexBuilder.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/index/IndexBuilder.java	2015-07-14 10:54:40.000000000 +0000
@@ -6,6 +6,7 @@
 
 import org.basex.core.*;
 import org.basex.data.*;
+import org.basex.index.value.*;
 import org.basex.util.*;
 
 /**
@@ -52,7 +53,7 @@
    * @return index instance
    * @throws IOException I/O Exception
    */
-  public abstract Index build() throws IOException;
+  public abstract ValueIndex build() throws IOException;
 
   /**
    * Checks if the command was interrupted, and prints some debug output.
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/index/Index.java basex-8.2.3/basex-core/src/main/java/org/basex/index/Index.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/index/Index.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/index/Index.java	2015-07-14 10:54:40.000000000 +0000
@@ -12,11 +12,6 @@
  */
 public interface Index {
   /**
-   * Initializes the index.
-   */
-  void init();
-
-  /**
    * Returns information on the index structure.
    * @param options main options
    * @return info
@@ -46,13 +41,13 @@
   int costs(final IndexToken token);
 
   /**
-   * Closes the index.
-   */
-  void close();
-
-  /**
    * Drops the index.
    * @return success flag
    */
   boolean drop();
+
+  /**
+   * Closes the index.
+   */
+  void close();
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/index/name/Names.java basex-8.2.3/basex-core/src/main/java/org/basex/index/name/Names.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/index/name/Names.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/index/name/Names.java	2015-07-14 10:54:40.000000000 +0000
@@ -47,7 +47,9 @@
     for(int s = 1; s < size; ++s) stats[s] = new Stats(in);
   }
 
-  @Override
+  /**
+   * Initializes the index.
+   */
   public void init() {
     for(int s = 1; s < size; ++s) stats[s] = new Stats();
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/index/path/PathSummary.java basex-8.2.3/basex-core/src/main/java/org/basex/index/path/PathSummary.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/index/path/PathSummary.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/index/path/PathSummary.java	2015-07-14 10:54:40.000000000 +0000
@@ -75,7 +75,9 @@
     data = dt;
   }
 
-  @Override
+  /**
+   * Initializes the index.
+   */
   public void init() {
     root = new PathNode();
     stack.clear();
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/index/query/FTIndexIterator.java basex-8.2.3/basex-core/src/main/java/org/basex/index/query/FTIndexIterator.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/index/query/FTIndexIterator.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/index/query/FTIndexIterator.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,6 +1,6 @@
 package org.basex.index.query;
 
-import org.basex.data.*;
+import org.basex.query.util.ft.*;
 
 /**
  * This interface provides methods for returning index results.
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/index/resource/Docs.java basex-8.2.3/basex-core/src/main/java/org/basex/index/resource/Docs.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/index/resource/Docs.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/index/resource/Docs.java	2015-07-14 10:54:40.000000000 +0000
@@ -6,7 +6,6 @@
 import java.io.*;
 
 import org.basex.data.*;
-import org.basex.data.atomic.*;
 import org.basex.io.in.DataInput;
 import org.basex.io.out.DataOutput;
 import org.basex.util.*;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/index/resource/Resources.java basex-8.2.3/basex-core/src/main/java/org/basex/index/resource/Resources.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/index/resource/Resources.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/index/resource/Resources.java	2015-07-14 10:54:40.000000000 +0000
@@ -4,7 +4,6 @@
 
 import org.basex.core.*;
 import org.basex.data.*;
-import org.basex.data.atomic.*;
 import org.basex.index.*;
 import org.basex.index.query.*;
 import org.basex.io.in.DataInput;
@@ -60,10 +59,6 @@
     return docs.docs();
   }
 
-  @Override
-  public synchronized void init() {
-  }
-
   /**
    * Adds entries to the index and updates subsequent nodes.
    * @param pre insertion position
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/index/value/DiskValues.java basex-8.2.3/basex-core/src/main/java/org/basex/index/value/DiskValues.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/index/value/DiskValues.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/index/value/DiskValues.java	2015-07-14 10:54:40.000000000 +0000
@@ -24,7 +24,7 @@
  * @author BaseX Team 2005-15, BSD License
  * @author Christian Gruen
  */
-public class DiskValues implements Index {
+public class DiskValues implements ValueIndex {
   /** ID references. */
   final DataAccess idxr;
   /** ID lists. */
@@ -69,9 +69,6 @@
   }
 
   @Override
-  public void init() { }
-
-  @Override
   public byte[] info(final MainOptions options) {
     final TokenBuilder tb = new TokenBuilder();
     tb.add(LI_STRUCTURE).add(SORTED_LIST).add(NL);
@@ -120,27 +117,13 @@
     }
   }
 
-  /**
-   * Add entries to the index.
-   * @param map a set of [key, id-list] pairs
-   */
-  @SuppressWarnings("unused")
+  @Override
   public void add(final TokenObjMap<IntList> map) { }
 
-  /**
-   * Deletes index entries from the index.
-   * @param map a set of [key, id-list] pairs
-   */
-  @SuppressWarnings("unused")
+  @Override
   public void delete(final TokenObjMap<IntList> map) { }
 
-  /**
-   * Replaces an index entry in the index.
-   * @param old old record key
-   * @param key new record key
-   * @param id record id
-   */
-  @SuppressWarnings("unused")
+  @Override
   public void replace(final byte[] old, final byte[] key, final int id) { }
 
   @Override
@@ -151,9 +134,7 @@
     return keysFrom(key, input.descending);
   }
 
-  /**
-   * Flushes the buffered data.
-   */
+  @Override
   public final void flush() {
     idxl.flush();
     idxr.flush();
@@ -504,10 +485,9 @@
       tb.add("- references:").add("\n");
       for(int m = 0; m < sz; m++) {
         final long pos = idxr.read5(m * 5L);
-        final int oc = idxl.readNum(pos);
-        int id = idxl.readNum();
-        tb.add("  ").addInt(m).add(". key: \"").add(data.text(pre(id), text)).add("\"; offset: ");
-        tb.addLong(pos).add("; id/dists: ").addInt(id).add('/').addInt(pre(id));
+        int oc = idxl.readNum(pos), id = idxl.readNum(), pre = pre(id);
+        tb.add("  ").addInt(m).add(". offset: ").addLong(pos).add(", key: \"");
+        tb.add(data.text(pre, text)).add("\", ids/pres: ").addInt(id).add('/').addInt(pre);
         for(int n = 1; n < oc; n++) {
           id += idxl.readNum();
           tb.add(",").addInt(id).add('/').addInt(pre(id));
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/index/value/MemValues.java basex-8.2.3/basex-core/src/main/java/org/basex/index/value/MemValues.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/index/value/MemValues.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/index/value/MemValues.java	2015-07-14 10:54:40.000000000 +0000
@@ -12,6 +12,7 @@
 import org.basex.index.stats.*;
 import org.basex.util.*;
 import org.basex.util.hash.*;
+import org.basex.util.list.*;
 
 /**
  * This class provides main memory access to attribute values and text contents.
@@ -19,7 +20,7 @@
  * @author BaseX Team 2005-15, BSD License
  * @author Christian Gruen
  */
-public final class MemValues extends TokenSet implements Index {
+public final class MemValues extends TokenSet implements ValueIndex {
   /** Updating index. */
   private final boolean updindex;
   /** Indexing flag. */
@@ -42,9 +43,6 @@
   }
 
   @Override
-  public void init() { }
-
-  @Override
   public IndexIterator iter(final IndexToken token) {
     final byte k = token.type() == IndexType.TEXT ? Data.TEXT : Data.ATTR;
     final int i = id(token.get());
@@ -137,6 +135,18 @@
   }
 
   @Override
+  public void add(final TokenObjMap<IntList> map) { }
+
+  @Override
+  public void delete(final TokenObjMap<IntList> map) { }
+
+  @Override
+  public void replace(final byte[] old, final byte[] key, final int id) { }
+
+  @Override
+  public void flush() { }
+
+  @Override
   public void close() { }
 
   @Override
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/index/value/UpdatableDiskValues.java basex-8.2.3/basex-core/src/main/java/org/basex/index/value/UpdatableDiskValues.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/index/value/UpdatableDiskValues.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/index/value/UpdatableDiskValues.java	2015-07-14 10:54:40.000000000 +0000
@@ -54,8 +54,9 @@
           c += idxl.readNum();
           il.add(c);
         }
-        // write new ids
+        // mark old slot as empty
         free.add((int) (idxl.cursor() - off), off);
+        // write new ids
         writeIds(key, il.add(ids), index++);
       } else {
         index = -(index + 1);
@@ -121,7 +122,7 @@
       // create space for new entry
       final int sz = size() + 1;
       final byte[] tmp = idxr.readBytes(0, sz * 5);
-      for(int i = sz - 1; i > index; --i) copy(tmp, i, i - 1);
+      for(int i = sz - 1; i > index; --i) copy(tmp, i - 1, i);
       idxr.cursor(0);
       idxr.writeBytes(tmp, 0, sz * 5);
       size(sz);
@@ -129,24 +130,18 @@
     } else {
       // add id to the existing id list
       final long off = idxr.read5(index * 5L);
-      final int num = idxl.readNum(off);
-      final int newSize = num + 1;
-      newIds = new IntList(newSize);
+      final int count = idxl.readNum(off);
+      newIds = new IntList(count + 1);
 
       boolean notadded = true;
-      int prevId = 0;
-      for(int i = 0; i < num; ++i) {
-        int v = idxl.readNum();
-        if(notadded && id < prevId + v) {
+      for(int c = 0, currId = 0; c < count; ++c) {
+        currId += idxl.readNum();
+        if(notadded && id < currId) {
           // add the new id
           newIds.add(id);
           notadded = false;
-          // decrement the difference to the next id
-          v -= id - prevId;
-          prevId = id;
         }
-        newIds.add(id);
-        prevId += v;
+        newIds.add(currId);
       }
       if(notadded) newIds.add(id);
     }
@@ -277,6 +272,6 @@
 
   @Override
   public String toString() {
-    return super.toString() + "FREE BLOCKS: " + free;
+    return super.toString() + free;
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/index/value/ValueIndex.java basex-8.2.3/basex-core/src/main/java/org/basex/index/value/ValueIndex.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/index/value/ValueIndex.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/index/value/ValueIndex.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,39 @@
+package org.basex.index.value;
+
+import org.basex.index.*;
+import org.basex.util.hash.*;
+import org.basex.util.list.*;
+
+/**
+ * This class provides index-supported access to values
+ * (attribute values, text contents, full-texts).
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Christian Gruen
+ */
+public interface ValueIndex extends Index {
+  /**
+   * Add entries to the index.
+   * @param map a set of [key, id-list] pairs
+   */
+  void add(final TokenObjMap<IntList> map);
+
+  /**
+   * Deletes index entries from the index.
+   * @param map a set of [key, id-list] pairs
+   */
+  void delete(final TokenObjMap<IntList> map);
+
+  /**
+   * Replaces an index entry in the index.
+   * @param old old record key
+   * @param key new record key
+   * @param id record id
+   */
+  void replace(final byte[] old, final byte[] key, final int id);
+
+  /**
+   * Flushes the buffered data.
+   */
+  void flush();
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/io/IOFile.java basex-8.2.3/basex-core/src/main/java/org/basex/io/IOFile.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/io/IOFile.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/io/IOFile.java	2015-07-14 10:54:40.000000000 +0000
@@ -109,7 +109,7 @@
 
   @Override
   public InputSource inputSource() {
-    return new InputSource(pth);
+    return new InputSource(url());
   }
 
   @Override
@@ -187,7 +187,7 @@
   }
 
   /**
-   * Returns the relative paths of all descendant files.
+   * Returns the relative paths of all descendant files (excluding directories).
    * @return relative paths
    */
   public synchronized StringList descendants() {
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/io/parse/csv/CsvMapConverter.java basex-8.2.3/basex-core/src/main/java/org/basex/io/parse/csv/CsvMapConverter.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/io/parse/csv/CsvMapConverter.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/io/parse/csv/CsvMapConverter.java	2015-07-14 10:54:40.000000000 +0000
@@ -4,7 +4,7 @@
 
 import org.basex.build.csv.*;
 import org.basex.query.*;
-import org.basex.query.iter.*;
+import org.basex.query.util.list.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.map.Map;
 
@@ -16,9 +16,9 @@
  */
 final class CsvMapConverter extends CsvConverter {
   /** All records. */
-  private final ArrayList<ValueBuilder> records = new ArrayList<>(1);
+  private final ArrayList<ItemList> records = new ArrayList<>(1);
   /** Current record. */
-  private ValueBuilder record = new ValueBuilder();
+  private ItemList record = new ItemList();
 
   /**
    * Constructor.
@@ -35,7 +35,7 @@
 
   @Override
   protected void record() {
-    record = new ValueBuilder();
+    record = new ItemList();
     if(!headers.isEmpty()) record.add(Map.EMPTY);
     records.add(record);
     col = 0;
@@ -61,8 +61,8 @@
     try {
       Map map = Map.EMPTY;
       int row = 1;
-      for(final ValueBuilder vb : records) {
-        map = map.put(Int.get(row++), vb.value(), null);
+      for(final ItemList list : records) {
+        map = map.put(Int.get(row++), list.value(), null);
       }
       return map;
     } catch(final QueryException ex) {
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/io/parse/json/JsonAttsConverter.java basex-8.2.3/basex-core/src/main/java/org/basex/io/parse/json/JsonAttsConverter.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/io/parse/json/JsonAttsConverter.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/io/parse/json/JsonAttsConverter.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,7 +1,6 @@
 package org.basex.io.parse.json;
 
 import static org.basex.io.parse.json.JsonConstants.*;
-import static org.basex.util.Token.*;
 
 import org.basex.build.json.*;
 import org.basex.query.value.node.*;
@@ -31,16 +30,18 @@
   }
 
   @Override
-  void openPair(final byte[] name) {
-    final FElem e = new FElem(PAIR).add(NAME, name);
-    curr.add(e);
-    curr = e;
-    nm = name;
+  void openPair(final byte[] name, final boolean add) {
+    if(add) {
+      final FElem e = new FElem(PAIR).add(NAME, name);
+      curr.add(e);
+      curr = e;
+      nm = name;
+    }
   }
 
   @Override
   void closePair(final boolean add) {
-    curr = (FElem) curr.parent();
+    if(add) curr = (FElem) curr.parent();
   }
 
   @Override
@@ -70,30 +71,6 @@
   }
 
   @Override
-  public void openConstr(final byte[] name) {
-    openObject();
-    openPair(name);
-    openArray();
-  }
-
-  @Override
-  public void openArg() {
-    openItem();
-  }
-
-  @Override
-  public void closeArg() {
-    closeItem();
-  }
-
-  @Override
-  public void closeConstr() {
-    closeArray();
-    closePair(true);
-    closeObject();
-  }
-
-  @Override
   public void numberLit(final byte[] value) {
     addType(NUMBER).add(value);
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/io/parse/json/JsonBasicConverter.java basex-8.2.3/basex-core/src/main/java/org/basex/io/parse/json/JsonBasicConverter.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/io/parse/json/JsonBasicConverter.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/io/parse/json/JsonBasicConverter.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,147 @@
+package org.basex.io.parse.json;
+
+import static org.basex.io.parse.json.JsonConstants.*;
+import static org.basex.query.QueryError.*;
+import static org.basex.util.Token.*;
+
+import org.basex.build.json.*;
+import org.basex.build.json.JsonParserOptions.JsonDuplicates;
+import org.basex.query.*;
+import org.basex.query.value.node.*;
+import org.basex.util.list.*;
+
+/**
+ * <p>This class converts a JSON document to XML.</p>
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Christian Gruen
+ */
+public final class JsonBasicConverter extends JsonXmlConverter {
+  /** Add pairs. */
+  private final BoolList addPairs = new BoolList();
+  /** Unescape characters. */
+  private final boolean unescape;
+  /** Name of next element. */
+  private byte[] name;
+
+  /**
+   * Constructor.
+   * @param opts json options
+   * @throws QueryIOException query I/O exception
+   */
+  JsonBasicConverter(final JsonParserOptions opts) throws QueryIOException {
+    super(opts);
+    unescape = jopts.get(JsonParserOptions.UNESCAPE);
+    addPairs.add(true);
+    final JsonDuplicates dupl = jopts.get(JsonParserOptions.DUPLICATES);
+    if(dupl == JsonDuplicates.USE_LAST) throw new QueryIOException(
+        BXJS_INVALID_X.get(null, JsonParserOptions.DUPLICATES.name(), dupl));
+  }
+
+  @Override
+  void openObject() {
+    open(MAP);
+  }
+
+  @Override
+  void openPair(final byte[] key, final boolean add) {
+    name = key;
+    addPairs.add(add() && add);
+  }
+
+  @Override
+  void closePair(final boolean add) {
+    addPairs.pop();
+  }
+
+  @Override
+  void closeObject() {
+    close();
+  }
+
+  @Override
+  void openArray() {
+    open(ARRAY);
+  }
+
+  @Override
+  void openItem() { }
+
+  @Override
+  void closeItem() { }
+
+  @Override
+  void closeArray() {
+    close();
+  }
+
+  @Override
+  public void numberLit(final byte[] value) {
+    if(add()) addElem(NUMBER).add(value);
+  }
+
+  @Override
+  public void stringLit(final byte[] value) {
+    if(add()) {
+      final FElem e = addElem(STRING).add(value);
+      if(!unescape && contains(value, '\\')) e.add(ESCAPED, TRUE);
+    }
+  }
+
+  @Override
+  public void nullLit() {
+    if(add()) addElem(NULL);
+  }
+
+  @Override
+  public void booleanLit(final byte[] value) {
+    if(add()) addElem(BOOLEAN).add(value);
+  }
+
+  /**
+   * Adds a new element with the given type.
+   * @param type JSON type
+   * @return new element
+   */
+  private FElem addElem(final byte[] type) {
+    final FElem e = new FElem(type, QueryText.FN_URI);
+    // root node: declare namespace
+    if(curr == null) e.declareNS();
+
+    if(name != null) {
+      e.add(KEY, name);
+      if(!unescape && contains(name, '\\')) e.add(ESCAPED_KEY, TRUE);
+      name = null;
+    }
+
+    if(curr != null) curr.add(e);
+    else curr = e;
+    return e;
+  }
+
+  /**
+   * Opens an entry.
+   * @param type JSON type
+   */
+  private void open(final byte[] type) {
+    if(add()) curr = addElem(type);
+  }
+
+  /**
+   * Closes an entry.
+   */
+  private void close() {
+    if(add()) {
+      final FElem par = (FElem) curr.parent();
+      if(par != null) curr = par;
+    }
+  }
+
+  /**
+   * Indicates if an entry should be added.
+   * @return result of check
+   */
+  private boolean add() {
+    return addPairs.peek();
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/io/parse/json/JsonConstants.java basex-8.2.3/basex-core/src/main/java/org/basex/io/parse/json/JsonConstants.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/io/parse/json/JsonConstants.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/io/parse/json/JsonConstants.java	2015-07-14 10:54:40.000000000 +0000
@@ -15,6 +15,12 @@
   byte[] TYPE = token("type");
   /** Token: item. */
   byte[] ITEM = token("item");
+  /** Token: key. */
+  byte[] KEY = token("key");
+  /** Token: escaped. */
+  byte[] ESCAPED = token("escaped");
+  /** Token: escaped-key. */
+  byte[] ESCAPED_KEY = token("escaped-key");
 
   /** Token: string. */
   byte[] STRING = token("string");
@@ -22,10 +28,16 @@
   byte[] NUMBER = token("number");
   /** Token: boolean. */
   byte[] BOOLEAN = token("boolean");
+  /** Token: null. */
+  byte[] NULL = token("null");
   /** Token: array. */
   byte[] ARRAY = token("array");
   /** Token: object. */
   byte[] OBJECT = token("object");
+  /** Token: map. */
+  byte[] MAP = token("map");
+  /** Allowed elements. */
+  byte[][] ELEMENTS = { STRING, NUMBER, BOOLEAN, NULL, MAP };
 
   /** Token: pair. */
   byte[] PAIR = token("pair");
@@ -36,6 +48,8 @@
 
   /** Supported data types. */
   byte[][] TYPES = { OBJECT, ARRAY, STRING, NUMBER, BOOLEAN, NULL };
+  /** Escape characters. */
+  byte[] ESCAPES = token("\"\\/bfnrtu");
   /** Plural. */
   byte[] S = { 's' };
   /** Global data type attributes. */
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/io/parse/json/JsonConverter.java basex-8.2.3/basex-core/src/main/java/org/basex/io/parse/json/JsonConverter.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/io/parse/json/JsonConverter.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/io/parse/json/JsonConverter.java	2015-07-14 10:54:40.000000000 +0000
@@ -66,12 +66,14 @@
    * Returns a JSON converter for the given configuration.
    * @param jopts options
    * @return JSON converter
+   * @throws QueryIOException query I/O exception
    */
-  public static JsonConverter get(final JsonParserOptions jopts) {
+  public static JsonConverter get(final JsonParserOptions jopts) throws QueryIOException {
     switch(jopts.get(JsonOptions.FORMAT)) {
       case JSONML:     return new JsonMLConverter(jopts);
       case ATTRIBUTES: return new JsonAttsConverter(jopts);
       case MAP:        return new JsonMapConverter(jopts);
+      case BASIC:      return new JsonBasicConverter(jopts);
       default:         return new JsonDirectConverter(jopts);
     }
   }
@@ -85,9 +87,10 @@
   /**
    * Called when a pair of a JSON object is opened.
    * @param key the key of the entry
+   * @param add add pair
    * @throws QueryIOException query exception
    */
-  abstract void openPair(byte[] key) throws QueryIOException;
+  abstract void openPair(byte[] key, boolean add) throws QueryIOException;
 
   /**
    * Called when a pair of a JSON object is closed.
@@ -125,30 +128,6 @@
   abstract void closeArray() throws QueryIOException;
 
   /**
-   * Called when a constructor function is opened.
-   * @param name name of the constructor
-   * @throws QueryIOException query exception
-   */
-  abstract void openConstr(byte[] name) throws QueryIOException;
-
-  /**
-   * Called when an argument of a constructor function is opened.
-   */
-  abstract void openArg();
-
-  /**
-   * Called when an argument of a constructor function is closed.
-   * @throws QueryIOException query exception
-   */
-  abstract void closeArg() throws QueryIOException;
-
-  /**
-   * Called when a constructor function is closed.
-   * @throws QueryIOException query exception
-   */
-  abstract void closeConstr() throws QueryIOException;
-
-  /**
    * Called when a number literal is encountered.
    * @param value string representation of the number literal
    * @throws QueryIOException query exception
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/io/parse/json/JsonDirectConverter.java basex-8.2.3/basex-core/src/main/java/org/basex/io/parse/json/JsonDirectConverter.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/io/parse/json/JsonDirectConverter.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/io/parse/json/JsonDirectConverter.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,7 +1,6 @@
 package org.basex.io.parse.json;
 
 import static org.basex.io.parse.json.JsonConstants.*;
-import static org.basex.util.Token.*;
 
 import org.basex.build.json.*;
 import org.basex.query.value.node.*;
@@ -64,28 +63,13 @@
     lax = jopts.get(JsonOptions.LAX);
   }
 
-  /**
-   * Adds a new element with the given type.
-   * @param type JSON type
-   * @return the element
-   */
-  private FElem addElem(final byte[] type) {
-    final FElem e = new FElem(name);
-    addType(e, e.name(), type);
-
-    if(curr != null) curr.add(e);
-    else curr = e;
-    name = null;
-    return e;
-  }
-
   @Override
   void openObject() {
     curr = addElem(OBJECT);
   }
 
   @Override
-  void openPair(final byte[] key) {
+  void openPair(final byte[] key, final boolean add) {
     name = XMLToken.encode(key, lax);
   }
 
@@ -117,31 +101,6 @@
   }
 
   @Override
-  public void openConstr(final byte[] nm) {
-    // [LW] what can be done here?
-    openObject();
-    openPair(nm);
-    openArray();
-  }
-
-  @Override
-  public void openArg() {
-    openItem();
-  }
-
-  @Override
-  public void closeArg() {
-    closeItem();
-  }
-
-  @Override
-  public void closeConstr() {
-    closeArray();
-    closePair(true);
-    closeObject();
-  }
-
-  @Override
   public void numberLit(final byte[] value) {
     addElem(NUMBER).add(value);
   }
@@ -160,4 +119,19 @@
   public void booleanLit(final byte[] value) {
     addElem(BOOLEAN).add(value);
   }
+
+  /**
+   * Adds a new element with the given type.
+   * @param type JSON type
+   * @return the element
+   */
+  private FElem addElem(final byte[] type) {
+    final FElem e = new FElem(name);
+    addType(e, e.name(), type);
+
+    if(curr != null) curr.add(e);
+    else curr = e;
+    name = null;
+    return e;
+  }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/io/parse/json/JsonFallback.java basex-8.2.3/basex-core/src/main/java/org/basex/io/parse/json/JsonFallback.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/io/parse/json/JsonFallback.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/io/parse/json/JsonFallback.java	2015-07-14 10:54:40.000000000 +0000
@@ -12,5 +12,5 @@
    * @param string input string
    * @return converted token
    */
-  public abstract byte[] convert(final byte[] string);
+  public abstract String convert(final String string);
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/io/parse/json/JsonMapConverter.java basex-8.2.3/basex-core/src/main/java/org/basex/io/parse/json/JsonMapConverter.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/io/parse/json/JsonMapConverter.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/io/parse/json/JsonMapConverter.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,8 +1,11 @@
 package org.basex.io.parse.json;
 
+import static org.basex.query.QueryError.*;
+
 import java.util.*;
 
 import org.basex.build.json.*;
+import org.basex.build.json.JsonParserOptions.JsonDuplicates;
 import org.basex.query.*;
 import org.basex.query.util.list.*;
 import org.basex.query.value.*;
@@ -43,9 +46,13 @@
   /**
    * Constructor.
    * @param opts json options
+   * @throws QueryIOException query I/O exception
    */
-  JsonMapConverter(final JsonParserOptions opts) {
+  JsonMapConverter(final JsonParserOptions opts) throws QueryIOException {
     super(opts);
+    final JsonDuplicates dupl = jopts.get(JsonParserOptions.DUPLICATES);
+    if(dupl == JsonDuplicates.RETAIN) throw new QueryIOException(
+        BXJS_INVALID_X.get(null, JsonParserOptions.DUPLICATES.name(), dupl));
   }
 
   @Override
@@ -60,7 +67,7 @@
   }
 
   @Override
-  void openPair(final byte[] key) {
+  void openPair(final byte[] key, final boolean add) {
     stack.push(Str.get(key));
   }
 
@@ -102,28 +109,6 @@
   }
 
   @Override
-  public void openConstr(final byte[] name) {
-    openObject();
-    openPair(name);
-    openArray();
-  }
-
-  @Override public void openArg() {
-    openItem();
-  }
-
-  @Override public void closeArg() throws QueryIOException {
-    closeItem();
-  }
-
-  @Override
-  public void closeConstr() throws QueryIOException {
-    closeArray();
-    closePair(true);
-    closeObject();
-  }
-
-  @Override
   public void numberLit(final byte[] value) throws QueryIOException {
     try {
       stack.push(Dbl.get(value, null));
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/io/parse/json/JsonMLConverter.java basex-8.2.3/basex-core/src/main/java/org/basex/io/parse/json/JsonMLConverter.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/io/parse/json/JsonMLConverter.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/io/parse/json/JsonMLConverter.java	2015-07-14 10:54:40.000000000 +0000
@@ -67,7 +67,7 @@
   }
 
   @Override
-  public void openPair(final byte[] key) throws QueryIOException {
+  public void openPair(final byte[] key, final boolean add) throws QueryIOException {
     attName = check(key);
   }
 
@@ -150,15 +150,4 @@
   public void booleanLit(final byte[] b) throws QueryIOException {
     error("No booleans allowed");
   }
-
-  @Override
-  public void openConstr(final byte[] nm) throws QueryIOException {
-    error("No constructor functions allowed");
-  }
-
-  @Override public void openArg() { }
-
-  @Override public void closeArg() { }
-
-  @Override public void closeConstr() { }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/io/parse/json/JsonParser.java basex-8.2.3/basex-core/src/main/java/org/basex/io/parse/json/JsonParser.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/io/parse/json/JsonParser.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/io/parse/json/JsonParser.java	2015-07-14 10:54:40.000000000 +0000
@@ -4,6 +4,7 @@
 import static org.basex.util.Token.*;
 
 import org.basex.build.json.*;
+import org.basex.build.json.JsonOptions.*;
 import org.basex.build.json.JsonParserOptions.JsonDuplicates;
 import org.basex.query.*;
 import org.basex.util.*;
@@ -48,7 +49,9 @@
     super(in);
     liberal = opts.get(JsonParserOptions.LIBERAL);
     unescape = opts.get(JsonParserOptions.UNESCAPE);
-    duplicates = opts.get(JsonParserOptions.DUPLICATES);
+    final JsonDuplicates dupl = opts.get(JsonParserOptions.DUPLICATES);
+    duplicates = dupl != null ? dupl : opts.get(JsonOptions.FORMAT) == JsonFormat.BASIC ?
+      JsonDuplicates.RETAIN : JsonDuplicates.USE_FIRST;
     this.conv = conv;
   }
 
@@ -73,6 +76,7 @@
    * @throws QueryIOException query I/O exception
    */
   private void parse() throws QueryIOException {
+    consume('\uFEFF');
     skipWs();
     value();
     if(more()) throw error("Unexpected trailing content: %", rest());
@@ -114,7 +118,6 @@
         if(consume("true")) conv.booleanLit(TRUE);
         else if(consume("false")) conv.booleanLit(FALSE);
         else if(consume("null")) conv.nullLit();
-        else if(liberal && consume("new") && Character.isWhitespace(curr())) constr();
         else throw error("Unexpected JSON value: '%'", rest());
         skipWs();
     }
@@ -135,10 +138,11 @@
         if(dupl && duplicates == JsonDuplicates.REJECT)
           throw error(BXJS_DUPLICATE_X, "Key '%' occurs more than once.", key);
 
-        conv.openPair(key);
+        final boolean add = !(dupl && duplicates == JsonDuplicates.USE_FIRST);
+        conv.openPair(key, add);
         consumeWs(':', true);
         value();
-        conv.closePair(!dupl || duplicates == JsonDuplicates.USE_LAST);
+        conv.closePair(add);
         set.put(key);
       } while(consumeWs(',', false) && !(liberal && curr() == '}'));
       consumeWs('}', true);
@@ -165,30 +169,6 @@
   }
 
   /**
-   * Parses a JSON constructor function.
-   * @throws QueryIOException query I/O exception
-   */
-  private void constr() throws QueryIOException {
-    skipWs();
-    if(!input.substring(pos).matches("^[a-zA-Z0-9_-]+\\(.*"))
-      throw error("Wrong constructor syntax: '%'", rest());
-
-    final int p = input.indexOf('(', pos);
-    conv.openConstr(token(input.substring(pos, p)));
-    pos = p + 1;
-    skipWs();
-    if(!consumeWs(')', false)) {
-      do {
-        conv.openArg();
-        value();
-        conv.closeArg();
-      } while(consumeWs(',', false));
-      consumeWs(')', true);
-    }
-    conv.closeConstr();
-  }
-
-  /**
    * Reads an unquoted string literal.
    * @return the string
    * @throws QueryIOException query I/O exception
@@ -295,7 +275,7 @@
       final int p = pos;
       int ch = consume();
       if(ch == '"') {
-        if(high != 0) tb.add(INVALID);
+        if(high != 0) add(high, pos - 7, p);
         skipWs();
         return tb.toArray();
       }
@@ -362,14 +342,14 @@
 
       if(high != 0) {
         if(ch >= 0xDC00 && ch <= 0xDFFF) ch = (high - 0xD800 << 10) + ch - 0xDC00 + 0x10000;
-        else tb.add(INVALID);
+        else add(high, p, pos);
         high = 0;
       }
 
       if(ch >= 0xD800 && ch <= 0xDBFF) {
         high = (char) ch;
       } else {
-        add(ch, p);
+        add(ch, p, pos);
       }
     }
     throw eof(" in string literal");
@@ -378,15 +358,16 @@
   /**
    * Adds the specified character.
    * @param ch character
-   * @param p start position of unescape sequence
+   * @param s start position of invalid unicode sequence
+   * @param e end position
    */
-  private void add(final int ch, final int p) {
+  private void add(final int ch, final int s, final int e) {
     if(XMLToken.valid(ch)) {
       tb.add(ch);
     } else if(conv.fallback == null) {
       tb.add(INVALID);
     } else {
-      tb.add(conv.fallback.convert(new TokenBuilder().add(input.substring(p, pos)).finish()));
+      tb.add(conv.fallback.convert(input.substring(s, e)));
     }
   }
 
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/io/serial/AdaptiveSerializer.java basex-8.2.3/basex-core/src/main/java/org/basex/io/serial/AdaptiveSerializer.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/io/serial/AdaptiveSerializer.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/io/serial/AdaptiveSerializer.java	2015-07-14 10:54:40.000000000 +0000
@@ -51,6 +51,13 @@
   }
 
   @Override
+  public Serializer sc(final StaticContext sctx) {
+    xml.sc(sctx);
+    json.sc(sctx);
+    return super.sc(sctx);
+  }
+
+  @Override
   public void serialize(final Item item) throws IOException {
     if(more) xml.printChars(itemsep);
     super.serialize(item);
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/io/serial/BuilderSerializer.java basex-8.2.3/basex-core/src/main/java/org/basex/io/serial/BuilderSerializer.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/io/serial/BuilderSerializer.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/io/serial/BuilderSerializer.java	2015-07-14 10:54:40.000000000 +0000
@@ -5,7 +5,7 @@
 import java.io.*;
 
 import org.basex.build.*;
-import org.basex.data.*;
+import org.basex.query.util.ft.*;
 import org.basex.util.*;
 
 /**
@@ -42,14 +42,14 @@
 
   @Override
   protected final void finishOpen() throws IOException {
-    builder.openElem(elem, atts, nsp);
+    builder.openElem(elem.string(), atts, nsp);
     atts.clear();
     nsp.clear();
   }
 
   @Override
   protected void finishEmpty() throws IOException {
-    builder.emptyElem(elem, atts, nsp);
+    builder.emptyElem(elem.string(), atts, nsp);
     atts.clear();
     nsp.clear();
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/io/serial/csv/CsvDirectSerializer.java basex-8.2.3/basex-core/src/main/java/org/basex/io/serial/csv/CsvDirectSerializer.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/io/serial/csv/CsvDirectSerializer.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/io/serial/csv/CsvDirectSerializer.java	2015-07-14 10:54:40.000000000 +0000
@@ -7,9 +7,10 @@
 
 import org.basex.build.csv.*;
 import org.basex.build.csv.CsvOptions.CsvFormat;
-import org.basex.data.*;
 import org.basex.io.out.*;
 import org.basex.io.serial.*;
+import org.basex.query.util.ft.*;
+import org.basex.query.value.item.*;
 import org.basex.util.*;
 import org.basex.util.hash.*;
 import org.basex.util.list.*;
@@ -52,7 +53,7 @@
   }
 
   @Override
-  protected void startOpen(final byte[] name) {
+  protected void startOpen(final QNm name) {
     if(level == 1) data = new TokenMap();
     attv = null;
   }
@@ -106,7 +107,7 @@
    */
   private void cache(final byte[] value) throws IOException {
     if(headers != null) {
-      final byte[] key = atts && attv != null ? attv : elem;
+      final byte[] key = atts && attv != null ? attv : elem.string();
       final byte[] name = XMLToken.decode(key, lax);
       if(name == null) error("Invalid element name <%>", key);
       if(!headers.contains(name)) headers.add(name);
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/io/serial/dot/DOTData.java basex-8.2.3/basex-core/src/main/java/org/basex/io/serial/dot/DOTData.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/io/serial/dot/DOTData.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/io/serial/dot/DOTData.java	2015-07-14 10:54:40.000000000 +0000
@@ -78,7 +78,7 @@
     // green
     { "009900", GFLWOR.class },
     { "339933", VarStack.class },
-    { "33CC33", For.class, Let.class, List.class, Range.class, Context.class,
+    { "33CC33", For.class, Let.class, List.class, Range.class, ContextValue.class,
                 QueryText.RET },
     { "66CC66", Var.class, Cast.class },
     // cyan
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/io/serial/dot/DOTSerializer.java basex-8.2.3/basex-core/src/main/java/org/basex/io/serial/dot/DOTSerializer.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/io/serial/dot/DOTSerializer.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/io/serial/dot/DOTSerializer.java	2015-07-14 10:54:40.000000000 +0000
@@ -7,10 +7,10 @@
 import java.io.*;
 import java.util.*;
 
-import org.basex.data.*;
 import org.basex.io.out.*;
 import org.basex.io.serial.*;
 import org.basex.query.*;
+import org.basex.query.util.ft.*;
 import org.basex.query.value.item.*;
 import org.basex.util.*;
 import org.basex.util.list.*;
@@ -53,7 +53,7 @@
   }
 
   @Override
-  protected void startOpen(final byte[] name) {
+  protected void startOpen(final QNm name) {
     tb.reset();
   }
 
@@ -65,9 +65,9 @@
   @Override
   protected void finishOpen() throws IOException {
     final byte[] attr = tb.toArray();
-    String color = color(elem);
+    String color = color(elem.string());
     if(color == null) color = attr.length == 0 ? ELEM1 : ELEM2;
-    print(concat(elem, attr), color);
+    print(concat(elem.string(), attr), color);
   }
 
   @Override
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/io/serial/HTMLSerializer.java basex-8.2.3/basex-core/src/main/java/org/basex/io/serial/HTMLSerializer.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/io/serial/HTMLSerializer.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/io/serial/HTMLSerializer.java	2015-07-14 10:54:40.000000000 +0000
@@ -7,6 +7,7 @@
 import java.io.*;
 
 import org.basex.io.out.*;
+import org.basex.query.value.item.*;
 import org.basex.util.hash.*;
 import org.basex.util.list.*;
 
@@ -47,10 +48,13 @@
     out.print(name);
 
     // don't append value for boolean attributes
-    final byte[] nm = concat(lc(elem), COLON, lc(name));
-    if(BOOLEAN.contains(nm) && eq(name, value)) return;
-    // escape URI attributes
-    final byte[] val = escuri && URIS.contains(nm) ? escape(value) : value;
+    byte[] val = value;
+    if(!BOOLEAN.isEmpty() || !URIS.isEmpty()) {
+      final byte[] nm = concat(lc(elem.string()), ATT, lc(name));
+      if(BOOLEAN.contains(nm) && eq(name, val)) return;
+      // escape URI attributes
+      if(escuri && URIS.contains(nm)) val = escape(val);
+    }
 
     out.print(ATT1);
     final int vl = val.length;
@@ -61,7 +65,7 @@
       } else if(ch == '"') {
         out.print(E_QUOT);
       } else if(ch == 0x9 || ch == 0xA) {
-        hex(ch);
+        printHex(ch);
       } else {
         encode(ch);
       }
@@ -97,30 +101,31 @@
   }
 
   @Override
-  protected void startOpen(final byte[] name) throws IOException {
+  protected void startOpen(final QNm name) throws IOException {
     doctype(null);
     if(sep) indent();
     out.print(ELEM_O);
-    out.print(name);
+    out.print(name.string());
     sep = indent;
-    script = SCRIPTS.contains(lc(name));
-    if(content && eq(lc(elem), HEAD)) ct++;
+    script = SCRIPTS.contains(lc(name.local()));
+    if(content && eq(lc(elem.local()), HEAD)) ct++;
   }
 
   @Override
   protected void finishOpen() throws IOException {
     super.finishOpen();
-    ct(false, true);
+    printCT(false, true);
   }
 
   @Override
   protected void finishEmpty() throws IOException {
-    if(ct(true, true)) return;
+    if(printCT(true, true)) return;
     out.print(ELEM_C);
+    final byte[] lc = lc(elem.local());
     if(html5) {
-      if(EMPTIES5.contains(lc(elem))) return;
+      if(EMPTIES5.contains(lc)) return;
     } else {
-      if(EMPTIES.contains(lc(elem))) {
+      if(EMPTIES.contains(lc)) {
         final byte[] u = nsUri(EMPTY);
         if(u == null || u.length == 0) return;
       }
@@ -132,21 +137,17 @@
   @Override
   protected void finishClose() throws IOException {
     super.finishClose();
-    script = script && !SCRIPTS.contains(lc(elem));
+    script = script && !SCRIPTS.contains(lc(elem.local()));
   }
 
   @Override
-  boolean doctype(final byte[] type) throws IOException {
-    if(level != 0) return false;
-    if(!super.doctype(type) && html5) {
-      if(sep) indent();
-      out.print(DOCTYPE);
-      if(type == null) out.print(HTML);
-      else out.print(type);
-      out.print(ELEM_C);
-      if(indent) newline();
+  protected void doctype(final QNm type) throws IOException {
+    final boolean doc = docpub != null || docsys != null;
+    if(doc) {
+      printDoctype(type, docpub, docsys);
+    } else if(html5) {
+      printDoctype(type, null, null);
     }
-    return true;
   }
 
   // HTML Serializer: cache elements
@@ -155,30 +156,30 @@
     SCRIPTS.add("script");
     SCRIPTS.add("style");
     // boolean attributes
-    BOOLEAN.add("area:nohref");
-    BOOLEAN.add("button:disabled");
-    BOOLEAN.add("dir:compact");
-    BOOLEAN.add("dl:compact");
-    BOOLEAN.add("frame:noresize");
-    BOOLEAN.add("hr:noshade");
-    BOOLEAN.add("img:ismap");
-    BOOLEAN.add("input:checked");
-    BOOLEAN.add("input:disabled");
-    BOOLEAN.add("input:readonly");
-    BOOLEAN.add("menu:compact");
-    BOOLEAN.add("object:declare");
-    BOOLEAN.add("ol:compact");
-    BOOLEAN.add("optgroup:disabled");
-    BOOLEAN.add("option:selected");
-    BOOLEAN.add("option:disabled");
-    BOOLEAN.add("script:defer");
-    BOOLEAN.add("select:multiple");
-    BOOLEAN.add("select:disabled");
-    BOOLEAN.add("td:nowrap");
-    BOOLEAN.add("textarea:disabled");
-    BOOLEAN.add("textarea:readonly");
-    BOOLEAN.add("th:nowrap");
-    BOOLEAN.add("ul:compact");
+    BOOLEAN.add("area@nohref");
+    BOOLEAN.add("button@disabled");
+    BOOLEAN.add("dir@compact");
+    BOOLEAN.add("dl@compact");
+    BOOLEAN.add("frame@noresize");
+    BOOLEAN.add("hr@noshade");
+    BOOLEAN.add("img@ismap");
+    BOOLEAN.add("input@checked");
+    BOOLEAN.add("input@disabled");
+    BOOLEAN.add("input@readonly");
+    BOOLEAN.add("menu@compact");
+    BOOLEAN.add("object@declare");
+    BOOLEAN.add("ol@compact");
+    BOOLEAN.add("optgroup@disabled");
+    BOOLEAN.add("option@selected");
+    BOOLEAN.add("option@disabled");
+    BOOLEAN.add("script@defer");
+    BOOLEAN.add("select@multiple");
+    BOOLEAN.add("select@disabled");
+    BOOLEAN.add("td@nowrap");
+    BOOLEAN.add("textarea@disabled");
+    BOOLEAN.add("textarea@readonly");
+    BOOLEAN.add("th@nowrap");
+    BOOLEAN.add("ul@compact");
     // elements with an empty content model
     EMPTIES.add("area");
     EMPTIES.add("base");
@@ -197,16 +198,13 @@
     // elements with an empty content model
     EMPTIES5.add("area");
     EMPTIES5.add("base");
-    EMPTIES5.add("basefont");
     EMPTIES5.add("br");
     EMPTIES5.add("col");
     EMPTIES5.add("command");
     EMPTIES5.add("embed");
-    EMPTIES5.add("frame");
     EMPTIES5.add("hr");
     EMPTIES5.add("img");
     EMPTIES5.add("input");
-    EMPTIES5.add("isindex");
     EMPTIES5.add("keygen");
     EMPTIES5.add("link");
     EMPTIES5.add("meta");
@@ -215,42 +213,42 @@
     EMPTIES5.add("track");
     EMPTIES5.add("wbr");
     // URI attributes
-    URIS.add("a:href");
-    URIS.add("a:name");
-    URIS.add("applet:codebase");
-    URIS.add("area:href");
-    URIS.add("base:href");
-    URIS.add("blockquote:cite");
-    URIS.add("body:background");
-    URIS.add("button:datasrc");
-    URIS.add("del:cite");
-    URIS.add("div:datasrc");
-    URIS.add("form:action");
-    URIS.add("frame:longdesc");
-    URIS.add("frame:src");
-    URIS.add("head:profile");
-    URIS.add("iframe:longdesc");
-    URIS.add("iframe:src");
-    URIS.add("img:longdesc");
-    URIS.add("img:src");
-    URIS.add("img:usemap");
-    URIS.add("input:datasrc");
-    URIS.add("input:src");
-    URIS.add("input:usemap");
-    URIS.add("ins:cite");
-    URIS.add("link:href");
-    URIS.add("object:archive");
-    URIS.add("object:classid");
-    URIS.add("object:codebase");
-    URIS.add("object:data");
-    URIS.add("object:datasrc");
-    URIS.add("object:usemap");
-    URIS.add("q:cite");
-    URIS.add("script:for");
-    URIS.add("script:src");
-    URIS.add("select:datasrc");
-    URIS.add("span:datasrc");
-    URIS.add("table:datasrc");
-    URIS.add("textarea:datasrc");
+    URIS.add("a@href");
+    URIS.add("a@name");
+    URIS.add("applet@codebase");
+    URIS.add("area@href");
+    URIS.add("base@href");
+    URIS.add("blockquote@cite");
+    URIS.add("body@background");
+    URIS.add("button@datasrc");
+    URIS.add("del@cite");
+    URIS.add("div@datasrc");
+    URIS.add("form@action");
+    URIS.add("frame@longdesc");
+    URIS.add("frame@src");
+    URIS.add("head@profile");
+    URIS.add("iframe@longdesc");
+    URIS.add("iframe@src");
+    URIS.add("img@longdesc");
+    URIS.add("img@src");
+    URIS.add("img@usemap");
+    URIS.add("input@datasrc");
+    URIS.add("input@src");
+    URIS.add("input@usemap");
+    URIS.add("ins@cite");
+    URIS.add("link@href");
+    URIS.add("object@archive");
+    URIS.add("object@classid");
+    URIS.add("object@codebase");
+    URIS.add("object@data");
+    URIS.add("object@datasrc");
+    URIS.add("object@usemap");
+    URIS.add("q@cite");
+    URIS.add("script@for");
+    URIS.add("script@src");
+    URIS.add("select@datasrc");
+    URIS.add("span@datasrc");
+    URIS.add("table@datasrc");
+    URIS.add("textarea@datasrc");
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/io/serial/json/JsonBasicSerializer.java basex-8.2.3/basex-core/src/main/java/org/basex/io/serial/json/JsonBasicSerializer.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/io/serial/json/JsonBasicSerializer.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/io/serial/json/JsonBasicSerializer.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,247 @@
+package org.basex.io.serial.json;
+
+import static org.basex.io.parse.json.JsonConstants.*;
+import static org.basex.query.QueryError.*;
+import static org.basex.util.Token.*;
+
+import java.io.*;
+
+import org.basex.io.out.*;
+import org.basex.io.parse.json.*;
+import org.basex.io.serial.*;
+import org.basex.query.*;
+import org.basex.query.iter.*;
+import org.basex.query.util.ft.*;
+import org.basex.query.value.item.*;
+import org.basex.query.value.node.*;
+import org.basex.query.value.type.*;
+import org.basex.util.*;
+import org.basex.util.list.*;
+
+/**
+ * This class serializes items as JSON. The input must conform to the rules
+ * defined in the {@link JsonDirectConverter} and {@link JsonAttsConverter} class.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Christian Gruen
+ */
+public final class JsonBasicSerializer extends JsonSerializer {
+  /** Output key. */
+  private boolean printKey;
+
+  /**
+   * Constructor.
+   * @param out print output
+   * @param opts serialization parameters
+   * @throws IOException I/O exception
+   */
+  public JsonBasicSerializer(final PrintOutput out, final SerializerOptions opts)
+      throws IOException {
+    super(out, opts);
+  }
+
+  @Override
+  protected void node(final ANode node) throws IOException {
+    if(level > 0) indent();
+
+    final BasicNodeIter iter = node.children();
+    if(node.type == NodeType.DOC || node.type == NodeType.DEL) {
+      final ANode child = iter.next();
+      if(child == null) throw error("Document has no child.");
+      if(iter.next() != null) throw error("Document has more than one child.");
+      node(child);
+    } else if(node.type == NodeType.ELM) {
+      final QNm name = node.qname();
+      final byte[] type = name.local();
+      if(!eq(name.uri(), QueryText.FN_URI))
+        throw error("Element '%' has invalid namespace: '%'.", type, name.uri());
+
+      byte[] key = node.attribute(KEY);
+      if(printKey) {
+        if(key == null) throw error("Element '%' has no key.", type);
+        out.print('"');
+        out.print(escape(key, node.attribute(ESCAPED_KEY)));
+        out.print("\":");
+      } else {
+        if(key != null) throw error("Element '%' must have no key.", type);
+      }
+
+      if(eq(type, NULL)) {
+        out.print(NULL);
+        if(iter.next() != null) throw error("Element '%' must have no children.", type);
+      } else if(eq(type, BOOLEAN)) {
+        byte[] value = value(iter, type);
+        if(value == null) throw error("Element '%' has no value.", type);
+        if(!eq(value, TRUE, FALSE)) throw error("Element '%' has invalid value: '%'.", type, value);
+        out.print(value);
+      } else if(eq(type, STRING)) {
+        byte[] value = value(iter, type);
+        out.print('"');
+        if(value != null) out.print(escape(value, node.attribute(ESCAPED)));
+        out.print('"');
+      } else if(eq(type, NUMBER)) {
+        byte[] value = value(iter, type);
+        if(value == null) throw error("Element '%' has no value.", type);
+        final Double d = toDouble(value);
+        if(d.isNaN() || d.isInfinite())
+          throw error("Element '%' has invalid value: '%'.", type, value);
+        out.print(value);
+      } else if(eq(type, ARRAY)) {
+        out.print('[');
+        children(iter, false);
+        out.print(']');
+      } else if(eq(type, MAP)) {
+        out.print('{');
+        children(iter, true);
+        out.print('}');
+      } else {
+        throw error("Invalid element: '%'", name);
+      }
+    } else {
+      throw error("Node must be an element.");
+    }
+  }
+
+  @Override
+  protected void startOpen(final QNm name) throws IOException {
+    throw Util.notExpected();
+  }
+
+  @Override
+  protected void attribute(final byte[] name, final byte[] value, final boolean standalone)
+      throws IOException {
+    throw Util.notExpected();
+  }
+
+  @Override
+  protected void finishOpen() throws IOException {
+    throw Util.notExpected();
+  }
+
+  @Override
+  protected void text(final byte[] value, final FTPos ftp) throws IOException {
+    throw Util.notExpected();
+  }
+
+  @Override
+  protected void finishEmpty() throws IOException {
+    throw Util.notExpected();
+  }
+
+  @Override
+  protected void finishClose() throws IOException {
+    throw Util.notExpected();
+  }
+
+  @Override
+  protected void atomic(final Item value) throws IOException {
+    throw BXJS_SERIAL_X.getIO("Atomic values cannot be serialized");
+  }
+
+  /**
+   * Serializes child nodes.
+   * @param iter iterator
+   * @param pk print keys
+   * @throws IOException I/O exception
+   */
+  private void children(final BasicNodeIter iter, final boolean pk) throws IOException {
+    boolean tmp = printKey;
+    printKey = pk;
+    level++;
+    boolean comma = false;
+    for(ANode child; (child = iter.next()) != null;) {
+      if(child.type == NodeType.ELM) {
+        if(comma) out.print(',');
+        node(child);
+        comma = true;
+      } else if(child.type == NodeType.TXT && !ws(child.string())) {
+        throw error("Element '%' must have no text nodes.", child.name());
+      }
+    }
+    level--;
+    indent();
+    printKey = tmp;
+  }
+
+  /**
+   * Returns the value of a node.
+   * @param iter iterator
+   * @param type type
+   * @return value
+   * @throws QueryIOException query exception
+   */
+  private byte[] value(final BasicNodeIter iter, final byte[] type) throws QueryIOException {
+    byte[] value = null;
+    for(ANode child; (child = iter.next()) != null;) {
+      if(child.type == NodeType.TXT) {
+        if(value != null) throw error("Element '%' has more than one child.", type);
+        value = child.string();
+      } else if(child.type == NodeType.ELM) {
+        throw error("Element '%' must have no elements as child.", type);
+      }
+    }
+    return value;
+  }
+
+  /**
+   * Returns a possibly escaped value.
+   * @param value value to escape
+   * @param flag escape flag
+   * @return escaped value
+   * @throws QueryIOException I/O exception
+   */
+  private byte[] escape(final byte[] value, final byte[] flag) throws QueryIOException {
+    if(flag != null && !eq(flag, FALSE, TRUE))
+      throw error("Value of escape attribute is invalid: '%'.", flag);
+
+    final boolean check = flag != null && eq(flag, TRUE);
+    if(check) {
+      if(contains(value, '\\')) {
+        final TokenParser tp = new TokenParser(value);
+        while(tp.more()) {
+          int c = tp.next();
+          if(c == '\\') {
+            if(!tp.more()) throw JSON_ESCAPE_X.getIO(value);
+            c = tp.next();
+            if(indexOf(ESCAPES, c) == -1) throw JSON_ESCAPE_X.getIO(value);
+            if(c == 'u') {
+              for(int i = 0; i < 4; i++) {
+                if(!tp.more()) throw JSON_ESCAPE_X.getIO(value);
+                c = tp.next();
+                if(c < '0' || c > '9' && c < 'A' || c > 'F' && c < 'a' || c > 'f')
+                  throw JSON_ESCAPE_X.getIO(value);
+              }
+            }
+          }
+        }
+      }
+    }
+
+    final ByteList bl = new ByteList();
+    for(final byte c : value) {
+      if(c < 32 || c >= 128 && c <= 160) {
+        bl.add('\\');
+        if(c == '\b') bl.add('b');
+        else if(c == '\f') bl.add('f');
+        else if(c == '\n') bl.add('n');
+        else if(c == '\r') bl.add('r');
+        else if(c == '\t') bl.add('t');
+        else bl.add('u').add('0').add('0').add(HEX[c >> 4]).add(HEX[c & 0xF]);
+      } else {
+        if(c == '"' || !check && c == '\\') bl.add('\\');
+        bl.add(c);
+      }
+    }
+    return bl.finish();
+  }
+
+  /**
+   * Raises an error with the specified message.
+   * @param msg error message
+   * @param ext error details
+   * @return I/O exception
+   */
+  private static QueryIOException error(final String msg, final Object... ext) {
+    return JSON_INVALID_X.getIO(Util.inf(msg, ext));
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/io/serial/json/JsonMLSerializer.java basex-8.2.3/basex-core/src/main/java/org/basex/io/serial/json/JsonMLSerializer.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/io/serial/json/JsonMLSerializer.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/io/serial/json/JsonMLSerializer.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,13 +1,12 @@
 package org.basex.io.serial.json;
 
 import static org.basex.query.QueryError.*;
-import static org.basex.util.Token.*;
 
 import java.io.*;
 
-import org.basex.data.*;
 import org.basex.io.out.*;
 import org.basex.io.serial.*;
+import org.basex.query.util.ft.*;
 import org.basex.query.value.item.*;
 
 /**
@@ -36,13 +35,13 @@
   }
 
   @Override
-  protected void startOpen(final byte[] name) throws IOException {
+  protected void startOpen(final QNm name) throws IOException {
     if(level != 0) {
       out.print(',');
       indent();
     }
     out.print("[\"");
-    for(final byte ch : local(name)) encode(ch);
+    for(final byte ch : name.local()) encode(ch);
     out.print('"');
     att = false;
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/io/serial/json/JsonNodeSerializer.java basex-8.2.3/basex-core/src/main/java/org/basex/io/serial/json/JsonNodeSerializer.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/io/serial/json/JsonNodeSerializer.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/io/serial/json/JsonNodeSerializer.java	2015-07-14 10:54:40.000000000 +0000
@@ -8,12 +8,13 @@
 
 import org.basex.build.json.*;
 import org.basex.build.json.JsonOptions.JsonFormat;
-import org.basex.data.*;
 import org.basex.io.out.*;
 import org.basex.io.parse.json.*;
 import org.basex.io.serial.*;
 import org.basex.query.*;
+import org.basex.query.util.ft.*;
 import org.basex.query.value.*;
+import org.basex.query.value.item.*;
 import org.basex.query.value.node.*;
 import org.basex.query.value.type.*;
 import org.basex.util.*;
@@ -100,10 +101,10 @@
   }
 
   @Override
-  protected void startOpen(final byte[] name) throws IOException {
+  protected void startOpen(final QNm name) throws IOException {
     types.set(level, null);
     comma.set(level + 1, false);
-    key = atts ? null : name;
+    key = atts ? null : name.string();
   }
 
   @Override
@@ -127,7 +128,7 @@
       types.set(level, value);
     } else if(atts && eq(name, NAME)) {
       key = value;
-      if(!eq(elem, PAIR)) throw error("<%> found, <pair> expected", elem);
+      if(!eq(elem.string(), PAIR)) throw error("<%> found, <pair> expected", elem);
     } else if(!eq(name, XMLNS) && !startsWith(name, XMLNSC)) {
       throw error("<%> has invalid attribute \"%\"", elem, name);
     }
@@ -142,7 +143,7 @@
       indent();
       final byte[] ptype = types.get(level - 1);
       if(eq(ptype, OBJECT)) {
-        if(atts && !eq(elem, PAIR)) throw error("<%> found, <%> expected", elem, PAIR);
+        if(atts && !eq(elem.string(), PAIR)) throw error("<%> found, <%> expected", elem, PAIR);
         if(key == null) throw error("<%> has no name attribute", elem);
         out.print('"');
         final byte[] name = atts ? key : XMLToken.decode(key, lax);
@@ -151,10 +152,10 @@
         out.print("\":");
       } else if(eq(ptype, ARRAY)) {
         if(atts) {
-          if(!eq(elem, ITEM)) throw error("<%> found, <%> expected", elem, ITEM);
+          if(!eq(elem.string(), ITEM)) throw error("<%> found, <%> expected", elem, ITEM);
           if(key != null) throw error("<%> must have no name attribute", elem);
         } else {
-          if(!eq(elem, VALUE)) throw error("<%> found, <%> expected", elem, VALUE);
+          if(!eq(elem.string(), VALUE)) throw error("<%> found, <%> expected", elem, VALUE);
         }
       } else {
         throw error("<%> is typed as \"%\" and cannot be nested", elems.get(level - 1), ptype);
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/io/serial/json/JsonSerializer.java basex-8.2.3/basex-core/src/main/java/org/basex/io/serial/json/JsonSerializer.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/io/serial/json/JsonSerializer.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/io/serial/json/JsonSerializer.java	2015-07-14 10:54:40.000000000 +0000
@@ -4,10 +4,10 @@
 import static org.basex.util.Token.*;
 
 import java.io.*;
-import java.util.*;
 
 import org.basex.build.json.*;
 import org.basex.io.out.*;
+import org.basex.io.parse.json.*;
 import org.basex.io.serial.*;
 import org.basex.query.*;
 import org.basex.query.value.*;
@@ -52,7 +52,7 @@
   public void serialize(final Item item) throws IOException {
     if(sep) throw SERJSON.getIO();
     if(item == null) {
-      out.print(NULL);
+      out.print(JsonConstants.NULL);
     } else {
       super.serialize(item);
     }
@@ -114,11 +114,10 @@
         out.print('[');
 
         boolean s = false;
-        final Iterator<Value> members = ((Array) item).members();
-        while(members.hasNext()) {
+        for(final Value val : ((Array) item).members()) {
           if(s) out.print(',');
           indent();
-          serialize(members.next());
+          serialize(val);
           s = true;
         }
 
@@ -198,7 +197,7 @@
 
   @Override
   public void close() throws IOException {
-    if(!sep) out.print(NULL);
+    if(!sep) out.print(JsonConstants.NULL);
     super.close();
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/io/serial/MarkupSerializer.java basex-8.2.3/basex-core/src/main/java/org/basex/io/serial/MarkupSerializer.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/io/serial/MarkupSerializer.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/io/serial/MarkupSerializer.java	2015-07-14 10:54:40.000000000 +0000
@@ -6,14 +6,15 @@
 import static org.basex.util.Token.*;
 
 import java.io.*;
+import java.util.*;
 
-import org.basex.data.*;
 import org.basex.io.out.*;
 import org.basex.query.*;
+import org.basex.query.util.ft.*;
+import org.basex.query.value.item.*;
 import org.basex.query.value.node.*;
 import org.basex.util.*;
 import org.basex.util.ft.*;
-import org.basex.util.hash.*;
 import org.basex.util.http.*;
 import org.basex.util.options.*;
 import org.basex.util.options.Options.YesNoOmit;
@@ -28,7 +29,7 @@
   /** System document type. */
   String docsys;
   /** Public document type. */
-  private String docpub;
+  String docpub;
   /** Flag for printing content type. */
   int ct;
 
@@ -46,11 +47,6 @@
   /** Undeclare prefixes. */
   final boolean undecl;
 
-  /** CData elements. */
-  private final TokenSet cdata = new TokenSet();
-  /** Suppress indentation elements. */
-  private final TokenSet suppress = new TokenSet();
-
   /** Media type. */
   private final String media;
 
@@ -97,25 +93,10 @@
       }
     }
 
-    final String supp = sopts.get(SUPPRESS_INDENTATION);
-    if(!supp.isEmpty()) {
-      for(final byte[] c : split(normalize(token(supp)), ' ')) {
-        if(c.length != 0) suppress.add(c);
-      }
-    }
-
-    // collect CData elements
     final boolean html = this instanceof HTMLSerializer;
     final boolean xml = this instanceof XMLSerializer || this instanceof XHTMLSerializer;
-    if(xml || html) {
-      final String cdse = sopts.get(CDATA_SECTION_ELEMENTS);
-      if(!cdse.isEmpty()) {
-        for(final byte[] c :  split(normalize(token(cdse)), ' ')) {
-          if(c.length == 0) continue;
-          if(!html || contains(c, ':') && (!html5 || !string(c).contains("html:"))) cdata.add(c);
-        }
-      }
 
+    if(xml || html) {
       if(undecl && ver.equals(V10)) throw SERUNDECL.getIO();
       if(xml) {
         if(omitDecl) {
@@ -160,7 +141,7 @@
       if(cp == '"') {
         out.print(E_QUOT);
       } else if(cp == 0x9 || cp == 0xA) {
-        hex(cp);
+        printHex(cp);
       } else {
         encode(cp);
       }
@@ -173,7 +154,8 @@
     final byte[] val = norm(value);
     final int vl = val.length;
     if(ftp == null) {
-      if(cdata.isEmpty() || elems.isEmpty() || !cdata.contains(elems.peek())) {
+      final ArrayList<QNm> qnames = cdata();
+      if(qnames.isEmpty() || elems.isEmpty() || !qnames.contains(elems.peek())) {
         for(int k = 0; k < vl; k += cl(val, k)) encode(cp(val, k));
       } else {
         out.print(CDATA_O);
@@ -232,11 +214,11 @@
   }
 
   @Override
-  protected void startOpen(final byte[] name) throws IOException {
+  protected void startOpen(final QNm name) throws IOException {
     doctype(name);
     if(sep) indent();
     out.print(ELEM_O);
-    out.print(name);
+    out.print(name.string());
     sep = true;
   }
 
@@ -254,7 +236,7 @@
   protected void finishClose() throws IOException {
     if(sep) indent();
     out.print(ELEM_OS);
-    out.print(elem);
+    out.print(elem.string());
     out.print(ELEM_C);
     sep = true;
   }
@@ -271,7 +253,7 @@
     }
 
     if(cp < ' ' && cp != '\n' && cp != '\t' || cp >= 0x7F && cp < 0xA0) {
-      hex(cp);
+      printHex(cp);
     } else if(cp == '&') {
       out.print(E_AMP);
     } else if(cp == '>') {
@@ -288,21 +270,36 @@
   /**
    * Prints the document type declaration.
    * @param type document type or {@code null} for html type
-   * @return true if doctype was added
    * @throws IOException I/O exception
    */
-  boolean doctype(final byte[] type) throws IOException {
-    if(level != 0 || docsys == null && docpub == null) return false;
+  protected abstract void doctype(final QNm type) throws IOException;
+
+  @Override
+  protected boolean ignore(final ANode node) {
+    return ct > 0 && eq(node.name(), META) && node.attribute(HTTPEQUIV) != null;
+  }
+
+  /**
+   * Prints the document type declaration.
+   * @param type document type or {@code null} for html type
+   * @param pub doctype-public parameter
+   * @param sys doctype-system parameter
+   * @throws IOException I/O exception
+   */
+  protected final void printDoctype(final QNm type, final String pub, final String sys)
+      throws IOException {
+
+    if(level != 0) return;
     if(sep) indent();
     out.print(DOCTYPE);
-    if(type == null) out.print(HTML);
-    else out.print(type);
-    if(docpub != null) out.print(' ' + PUBLIC + " \"" + docpub + '"');
-    else out.print(' ' + SYSTEM);
-    if(docsys != null) out.print(" \"" + docsys + '"');
+    out.print(type == null ? HTML : type.string());
+    if(sys != null || pub != null) {
+      if(pub != null) out.print(' ' + PUBLIC + " \"" + pub + '"');
+      else out.print(' ' + SYSTEM);
+      if(sys != null) out.print(" \"" + sys + '"');
+    }
     out.print(ELEM_C);
     sep = true;
-    return true;
   }
 
   @Override
@@ -310,8 +307,11 @@
     if(atomic) {
       atomic = false;
     } else if(indent) {
-      if(!suppress.isEmpty() && !elems.isEmpty()) {
-        for(final byte[] t : elems) if(suppress.contains(t)) return;
+      final ArrayList<QNm> qnames = suppress();
+      if(!qnames.isEmpty()) {
+        for(final QNm e : elems) {
+          if(qnames.contains(e)) return;
+        }
       }
       super.indent();
     }
@@ -322,7 +322,7 @@
    * @param cp codepoint (00-FF)
    * @throws IOException I/O exception
    */
-  final void hex(final int cp) throws IOException {
+  protected final void printHex(final int cp) throws IOException {
     out.print("&#x");
     if(cp > 0xF) out.print(HEX[cp >> 4]);
     out.print(HEX[cp & 0xF]);
@@ -336,12 +336,12 @@
    * @return {@code true} if declaration was printed
    * @throws IOException I/O exception
    */
-  boolean ct(final boolean empty, final boolean html) throws IOException {
+  protected final boolean printCT(final boolean empty, final boolean html) throws IOException {
     if(ct != 1) return false;
     ct++;
     if(empty) finishOpen();
     level++;
-    startOpen(META);
+    startOpen(new QNm(META));
     attribute(HTTPEQUIV, CONTENT_TYPE, false);
     attribute(CONTENT, new TokenBuilder(media.isEmpty() ? MediaType.TEXT_HTML.toString() : media).
         add("; ").add(CHARSET).add('=').addExt(out.encoding()).finish(), false);
@@ -356,11 +356,6 @@
     return true;
   }
 
-  @Override
-  protected boolean ignore(final ANode node) {
-    return ct > 0 && eq(node.name(), META) && node.attribute(HTTPEQUIV) != null;
-  }
-
   // PRIVATE METHODS ==============================================================================
 
   /**
@@ -379,4 +374,65 @@
     for(final String a : allowed) if(a.equals(val)) return val;
     throw SERNOTSUPP_X.getIO(Options.allowed(option, (Object[]) allowed));
   }
+
+  /** CData elements. */
+  private ArrayList<QNm> cdata;
+
+  /**
+   * Initializes the CData elements.
+   * @return list
+   * @throws QueryIOException query I/O exception
+   */
+  private ArrayList<QNm> cdata() throws QueryIOException {
+    ArrayList<QNm> list = cdata;
+    if(list == null) {
+      list = new ArrayList<>();
+      final boolean html = this instanceof HTMLSerializer;
+      final String cdse = sopts.get(CDATA_SECTION_ELEMENTS);
+      for(final byte[] name : split(normalize(token(cdse)), ' ')) {
+        if(name.length == 0) continue;
+        final QNm qnm = resolve(name);
+        if(!html || contains(name, ':') && (!html5 || !string(name).contains("html:"))) {
+          list.add(qnm);
+        }
+      }
+      cdata = list;
+    }
+    return list;
+  }
+
+  /** Suppress indentation elements. */
+  private ArrayList<QNm> suppress;
+
+  /**
+   * Initializes and returns the elements whose contents must not be indented.
+   * @return list
+   * @throws QueryIOException query I/O exception
+   */
+  private ArrayList<QNm> suppress() throws QueryIOException {
+    ArrayList<QNm> list = suppress;
+    if(list == null) {
+      list = new ArrayList<>();
+      final String supp = sopts.get(SUPPRESS_INDENTATION);
+      for(final byte[] name : split(normalize(token(supp)), ' ')) {
+        if(name.length != 0) list.add(resolve(name));
+      }
+      suppress = list;
+    }
+    return list;
+  }
+
+  /**
+   * Resolves a QName.
+   * @param name name to be resolved
+   * @return list
+   * @throws QueryIOException query I/O exception
+   */
+  private QNm resolve(final byte[] name) throws QueryIOException {
+    try {
+      return QNm.resolve(name, sc == null ? null : sc.elemNS, sc, null);
+    } catch(final QueryException ex) {
+      throw new QueryIOException(ex);
+    }
+  }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/io/serial/RawSerializer.java basex-8.2.3/basex-core/src/main/java/org/basex/io/serial/RawSerializer.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/io/serial/RawSerializer.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/io/serial/RawSerializer.java	2015-07-14 10:54:40.000000000 +0000
@@ -2,9 +2,9 @@
 
 import java.io.*;
 
-import org.basex.data.*;
 import org.basex.io.out.*;
 import org.basex.query.*;
+import org.basex.query.util.ft.*;
 import org.basex.query.value.item.*;
 
 /**
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/io/serial/SAXSerializer.java basex-8.2.3/basex-core/src/main/java/org/basex/io/serial/SAXSerializer.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/io/serial/SAXSerializer.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/io/serial/SAXSerializer.java	2015-07-14 10:54:40.000000000 +0000
@@ -4,7 +4,7 @@
 
 import java.io.*;
 
-import org.basex.data.*;
+import org.basex.query.util.ft.*;
 import org.basex.query.value.item.*;
 import org.basex.util.*;
 import org.xml.sax.*;
@@ -140,7 +140,7 @@
   private NSDecl namespaces;
 
   @Override
-  protected void startOpen(final byte[] name) {
+  protected void startOpen(final QNm name) {
     namespaces = new NSDecl(namespaces);
     attributes.clear();
   }
@@ -177,9 +177,9 @@
         attrs.addAttribute(uri, lname, rname, null, value);
       }
 
-      final String uri = string(namespaces.get(prefix(elem)));
-      final String lname = string(local(elem));
-      final String rname = string(elem);
+      final String uri = string(namespaces.get(elem.prefix()));
+      final String lname = string(elem.local());
+      final String rname = string(elem.string());
       contentHandler.startElement(uri, lname, rname, attrs);
 
     } catch(final SAXException ex) {
@@ -196,7 +196,7 @@
   @Override
   protected void finishClose() throws IOException {
     try {
-      final String name = string(elem);
+      final String name = string(elem.string());
       contentHandler.endElement("", name, name);
       namespaces = namespaces.getParent();
     } catch(final SAXException ex) {
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/io/serial/Serializer.java basex-8.2.3/basex-core/src/main/java/org/basex/io/serial/Serializer.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/io/serial/Serializer.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/io/serial/Serializer.java	2015-07-14 10:54:40.000000000 +0000
@@ -6,6 +6,7 @@
 
 import java.io.*;
 import java.nio.charset.*;
+import java.util.*;
 
 import org.basex.build.csv.*;
 import org.basex.build.csv.CsvOptions.CsvFormat;
@@ -17,6 +18,7 @@
 import org.basex.io.serial.json.*;
 import org.basex.query.*;
 import org.basex.query.iter.*;
+import org.basex.query.util.ft.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.node.*;
 import org.basex.query.value.type.*;
@@ -32,11 +34,11 @@
  */
 public abstract class Serializer implements Closeable {
   /** Stack with names of opened elements. */
-  protected final TokenList elems = new TokenList();
+  protected final Stack<QNm> elems = new Stack<>();
   /** Current level. */
   protected int level;
   /** Current element name. */
-  protected byte[] elem;
+  protected QNm elem;
   /** Indentation flag. */
   protected boolean indent;
 
@@ -45,6 +47,8 @@
   /** Stack with namespace size pointers. */
   private final IntList nstack = new IntList();
 
+  /** Static context. */
+  protected StaticContext sc;
   /** Indicates if more than one item was serialized. */
   protected boolean more;
   /** Indicates if an element is currently being opened. */
@@ -99,9 +103,10 @@
                : new CsvDirectSerializer(po, so);
       case JSON:
         final JsonSerialOptions jopts = so.get(SerializerOptions.JSON);
-        return jopts.get(JsonOptions.FORMAT) == JsonFormat.JSONML
-               ? new JsonMLSerializer(po, so)
-               : new JsonNodeSerializer(po, so);
+        final JsonFormat jformat = jopts.get(JsonOptions.FORMAT);
+        return jformat == JsonFormat.JSONML ? new JsonMLSerializer(po, so) :
+               jformat == JsonFormat.BASIC  ? new JsonBasicSerializer(po, so) :
+               new JsonNodeSerializer(po, so);
       case XML:
         return new XMLSerializer(po, so);
       default:
@@ -147,6 +152,16 @@
    */
   public void reset() { }
 
+  /**
+   * Assigns the static context.
+   * @param sctx static context
+   * @return serializer
+   */
+  public Serializer sc(final StaticContext sctx) {
+    sc = sctx;
+    return this;
+  }
+
   // PROTECTED METHODS ==================================================================
 
   /**
@@ -178,7 +193,7 @@
       } else {
         // serialize elements (code will never be called for attributes)
         final QNm name = node.qname();
-        openElement(name.string());
+        openElement(name);
 
         // serialize declared namespaces
         final Atts nsp = node.namespaces();
@@ -188,8 +203,8 @@
 
         // serialize attributes
         final boolean i = indent;
-        AxisMoreIter ai = node.attributes();
-        for(ANode nd; (nd = ai.next()) != null;) {
+        BasicNodeIter iter = node.attributes();
+        for(ANode nd; (nd = iter.next()) != null;) {
           final byte[] n = nd.name();
           final byte[] v = nd.string();
           attribute(n, v, false);
@@ -197,8 +212,8 @@
         }
 
         // serialize children
-        ai = node.children();
-        for(ANode n; (n = ai.next()) != null;) node(n);
+        iter = node.children();
+        for(ANode n; (n = iter.next()) != null;) node(n);
         closeElement();
         indent = i;
       }
@@ -210,7 +225,7 @@
    * @param name element name
    * @throws IOException I/O exception
    */
-  protected final void openElement(final byte[] name) throws IOException {
+  protected final void openElement(final QNm name) throws IOException {
     prepare();
     opening = true;
     elem = name;
@@ -228,9 +243,10 @@
       finishEmpty();
       opening = false;
     } else {
-      elem = elems.pop();
+      elem = elems.peek();
       level--;
       finishClose();
+      elems.pop();
     }
   }
 
@@ -305,7 +321,7 @@
    * @throws IOException I/O exception
    */
   @SuppressWarnings("unused")
-  protected void startOpen(final byte[] name) throws IOException { }
+  protected void startOpen(final QNm name) throws IOException { }
 
   /**
    * Finishes an opening element node.
@@ -379,21 +395,21 @@
    */
   private void node(final DBNode node) throws IOException {
     final FTPosData ft = node instanceof FTPosNode ? ((FTPosNode) node).ftpos : null;
-    final Data data = node.data;
-    int p = node.pre;
-    int k = data.kind(p);
-    if(k == Data.ATTR) throw SERATTR_X.getIO(node);
+    final Data data = node.data();
+    int pre = node.pre();
+    int kind = data.kind(pre);
+    if(kind == Data.ATTR) throw SERATTR_X.getIO(node);
 
     boolean doc = false;
-    final TokenSet nsp = data.nspaces.size() == 0 ? null : new TokenSet();
+    final TokenSet nsp = data.nspaces.isEmpty() ? null : new TokenSet();
     final IntList pars = new IntList();
     final BoolList indt = new BoolList();
 
     // loop through all table entries
-    final int s = p + data.size(p, k);
-    while(p < s && !finished()) {
-      k = data.kind(p);
-      final int r = data.parent(p, k);
+    final int s = pre + data.size(pre, kind);
+    while(pre < s && !finished()) {
+      kind = data.kind(pre);
+      final int r = data.parent(pre, kind);
 
       // close opened elements...
       while(!pars.isEmpty() && pars.peek() >= r) {
@@ -402,35 +418,35 @@
         pars.pop();
       }
 
-      if(k == Data.DOC) {
+      if(kind == Data.DOC) {
         if(doc) closeDoc();
-        openDoc(data.text(p++, true));
+        openDoc(data.text(pre++, true));
         doc = true;
-      } else if(k == Data.TEXT) {
-        prepareText(data.text(p, true), ft != null ? ft.get(data, p) : null);
-        p++;
-      } else if(k == Data.COMM) {
-        prepareComment(data.text(p++, true));
+      } else if(kind == Data.TEXT) {
+        prepareText(data.text(pre, true), ft != null ? ft.get(data, pre) : null);
+        pre++;
+      } else if(kind == Data.COMM) {
+        prepareComment(data.text(pre++, true));
       } else {
-        if(k == Data.PI) {
-          preparePi(data.name(p, Data.PI), data.atom(p++));
+        if(kind == Data.PI) {
+          preparePi(data.name(pre, Data.PI), data.atom(pre++));
         } else {
           // add element node
-          final byte[] name = data.name(p, k);
-          openElement(name);
+          final byte[] name = data.name(pre, kind);
+          final byte[] uri = data.nspaces.uri(data.uriId(pre, kind));
+          openElement(new QNm(name, uri));
 
           // add namespace definitions
           if(nsp != null) {
             // add namespaces from database
             nsp.clear();
-            int pp = p;
+            int pp = pre;
 
             // check namespace of current element
-            final byte[] u = data.nspaces.uri(data.uri(p, k));
-            namespace(prefix(name), u == null ? EMPTY : u, false);
+            namespace(prefix(name), uri == null ? EMPTY : uri, false);
 
             do {
-              final Atts ns = data.ns(pp);
+              final Atts ns = data.namespaces(pp);
               final int nl = ns.size();
               for(int n = 0; n < nl; n++) {
                 final byte[] pref = ns.name(n);
@@ -445,10 +461,10 @@
 
           // serialize attributes
           indt.push(indent);
-          final int as = p + data.attSize(p, k);
-          while(++p != as) {
-            final byte[] n = data.name(p, Data.ATTR);
-            final byte[] v = data.text(p, false);
+          final int as = pre + data.attSize(pre, kind);
+          while(++pre != as) {
+            final byte[] n = data.name(pre, Data.ATTR);
+            final byte[] v = data.text(pre, false);
             attribute(n, v, false);
             if(eq(n, XML_SPACE) && indent) indent = !eq(v, PRESERVE);
           }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/io/serial/TextSerializer.java basex-8.2.3/basex-core/src/main/java/org/basex/io/serial/TextSerializer.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/io/serial/TextSerializer.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/io/serial/TextSerializer.java	2015-07-14 10:54:40.000000000 +0000
@@ -2,8 +2,8 @@
 
 import java.io.*;
 
-import org.basex.data.*;
 import org.basex.io.out.*;
+import org.basex.query.util.ft.*;
 
 /**
  * This class serializes items as text.
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/io/serial/XHTMLSerializer.java basex-8.2.3/basex-core/src/main/java/org/basex/io/serial/XHTMLSerializer.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/io/serial/XHTMLSerializer.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/io/serial/XHTMLSerializer.java	2015-07-14 10:54:40.000000000 +0000
@@ -6,6 +6,7 @@
 import java.io.*;
 
 import org.basex.io.out.*;
+import org.basex.query.value.item.*;
 
 /**
  * This class serializes items as XHTML.
@@ -29,27 +30,30 @@
       throws IOException {
 
     // escape URI attributes
-    final byte[] nm = concat(lc(elem), COLON, lc(name));
+    final byte[] nm = concat(lc(elem.local()), COLON, lc(name));
     final byte[] val = escuri && HTMLSerializer.URIS.contains(nm) ? escape(value) : value;
     super.attribute(name, val, standalone);
   }
 
   @Override
-  protected void startOpen(final byte[] value) throws IOException {
+  protected void startOpen(final QNm value) throws IOException {
     super.startOpen(value);
-    if(content && eq(lc(elem), HEAD)) ct++;
+    if(content && eq(lc(elem.local()), HEAD)) ct++;
   }
 
   @Override
   protected void finishOpen() throws IOException {
     super.finishOpen();
-    ct(false, false);
+    printCT(false, false);
   }
 
   @Override
   protected void finishEmpty() throws IOException {
-    if(ct(true, false)) return;
-    if((html5 ? HTMLSerializer.EMPTIES5 : HTMLSerializer.EMPTIES).contains(lc(elem))) {
+    if(printCT(true, false)) return;
+    final byte[] lc = lc(elem.local());
+    if(html5 && HTMLSerializer.EMPTIES5.contains(lc)) {
+      out.print(ELEM_SC);
+    } else if(!html5 && HTMLSerializer.EMPTIES.contains(lc) && eq(elem.uri(), XHTML_URI)) {
       out.print(' ');
       out.print(ELEM_SC);
     } else {
@@ -60,16 +64,11 @@
   }
 
   @Override
-  protected boolean doctype(final byte[] type) throws IOException {
-    if(level != 0) return false;
-    if(!super.doctype(type) && html5) {
-      if(sep) indent();
-      out.print(DOCTYPE);
-      if(type == null) out.print(HTML);
-      else out.print(type);
-      out.print(ELEM_C);
-      newline();
+  protected void doctype(final QNm type) throws IOException {
+    if(html5 && docsys == null) {
+      printDoctype(type, null, null);
+    } else if(docsys != null) {
+      printDoctype(type, docpub, docsys);
     }
-    return true;
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/io/serial/XMLSerializer.java basex-8.2.3/basex-core/src/main/java/org/basex/io/serial/XMLSerializer.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/io/serial/XMLSerializer.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/io/serial/XMLSerializer.java	2015-07-14 10:54:40.000000000 +0000
@@ -5,9 +5,9 @@
 
 import java.io.*;
 
-import org.basex.data.*;
 import org.basex.io.out.*;
 import org.basex.query.*;
+import org.basex.query.util.ft.*;
 import org.basex.query.value.item.*;
 
 /**
@@ -31,7 +31,7 @@
   }
 
   @Override
-  protected void startOpen(final byte[] name) throws IOException {
+  protected void startOpen(final QNm name) throws IOException {
     if(elems.isEmpty()) {
       if(root) check();
       root = true;
@@ -51,6 +51,11 @@
     super.atomic(it);
   }
 
+  @Override
+  protected void doctype(final QNm type) throws IOException {
+    if(docsys != null) printDoctype(type, docpub, docsys);
+  }
+
   /**
    * Checks if document serialization is valid.
    * @throws QueryIOException query I/O exception
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/BaseXPragma.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/BaseXPragma.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/BaseXPragma.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/BaseXPragma.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,41 @@
+package org.basex.query.expr;
+
+import org.basex.query.*;
+import org.basex.query.expr.Expr.Flag;
+import org.basex.query.value.item.*;
+import org.basex.util.*;
+
+/**
+ * Pragma for database options.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Leo Woerteler
+ */
+public final class BaseXPragma extends Pragma {
+  /**
+   * Constructor.
+   * @param name name of pragma
+   * @param value optional value
+   */
+  public BaseXPragma(final QNm name, final byte[] value) {
+    super(name, value);
+  }
+
+  @Override
+  void init(final QueryContext qc, final InputInfo info) throws QueryException {
+  }
+
+  @Override
+  void finish(final QueryContext qc) {
+  }
+
+  @Override
+  public boolean has(final Flag flag) {
+    return flag == Flag.NDT && Token.eq(name.local(), Token.token(QueryText.NON_DETERMNISTIC));
+  }
+
+  @Override
+  public Pragma copy() {
+    return new BaseXPragma(name, value);
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/CachedFilter.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/CachedFilter.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/CachedFilter.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/CachedFilter.java	2015-07-14 10:54:40.000000000 +0000
@@ -2,6 +2,7 @@
 
 import org.basex.query.*;
 import org.basex.query.iter.*;
+import org.basex.query.util.list.*;
 import org.basex.query.value.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.node.*;
@@ -28,6 +29,11 @@
 
   @Override
   public Iter iter(final QueryContext qc) throws QueryException {
+    return value(qc).iter();
+  }
+
+  @Override
+  public Value value(final QueryContext qc) throws QueryException {
     Value val = root.value(qc);
     final Value cv = qc.value;
     final long cs = qc.size;
@@ -35,7 +41,7 @@
 
     try {
       // evaluate first predicate, based on incoming value
-      final ValueBuilder vb = new ValueBuilder();
+      final ItemList buffer = new ItemList();
       Expr pred = preds[0];
       long vs = val.size();
       qc.size = vs;
@@ -48,7 +54,7 @@
         final Item test = pred.test(qc, info);
         if(test != null) {
           if(scoring) item.score(test.score());
-          vb.add(item);
+          buffer.add(item);
         }
         qc.pos++;
       }
@@ -58,26 +64,26 @@
       // evaluate remaining predicates, based on value builder
       final int pl = preds.length;
       for(int i = 1; i < pl; i++) {
-        vs = vb.size();
+        vs = buffer.size();
         pred = preds[i];
         qc.size = vs;
         qc.pos = 1;
         int c = 0;
         for(int s = 0; s < vs; ++s) {
-          final Item item = vb.get(s);
+          final Item item = buffer.get(s);
           qc.value = item;
           final Item test = pred.test(qc, info);
           if(test != null) {
             if(scoring) item.score(test.score());
-            vb.set(c++, item);
+            buffer.set(c++, item);
           }
           qc.pos++;
         }
-        vb.size(c);
+        buffer.size(c);
       }
 
       // return resulting values
-      return vb;
+      return buffer.value();
     } finally {
       qc.value = cv;
       qc.size = cs;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/CachedMap.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/CachedMap.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/CachedMap.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/CachedMap.java	2015-07-14 10:54:40.000000000 +0000
@@ -2,6 +2,7 @@
 
 import org.basex.query.*;
 import org.basex.query.iter.*;
+import org.basex.query.util.list.*;
 import org.basex.query.value.*;
 import org.basex.query.value.item.*;
 import org.basex.query.var.*;
@@ -26,15 +27,20 @@
 
   @Override
   public Iter iter(final QueryContext qc) throws QueryException {
+    return value(qc).iter();
+  }
+
+  @Override
+  public Value value(final QueryContext qc) throws QueryException {
     final Value cv = qc.value;
     final long cp = qc.pos, cs = qc.size;
     try {
-      ValueBuilder result = new ValueBuilder().add(qc.value(exprs[0]));
+      ItemList result = qc.value(exprs[0]).cache();
       final int el = exprs.length;
       for(int e = 1; e < el; e++) {
         qc.pos = 0;
         qc.size = result.size();
-        final ValueBuilder vb = new ValueBuilder((int) result.size());
+        final ItemList vb = new ItemList(result.size());
         for(final Item it : result) {
           qc.pos++;
           qc.value = it;
@@ -42,7 +48,7 @@
         }
         result = vb;
       }
-      return result;
+      return result.value();
     } finally {
       qc.value = cv;
       qc.size = cs;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/CmpR.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/CmpR.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/CmpR.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/CmpR.java	2015-07-14 10:54:40.000000000 +0000
@@ -71,13 +71,15 @@
    * @return new or original expression
    */
   static ParseExpr get(final CmpG cmp) {
-    final Expr e = cmp.exprs[1];
-    if(e instanceof RangeSeq) {
-      final RangeSeq rs = (RangeSeq) e;
+    final Expr e1 = cmp.exprs[0], e2 = cmp.exprs[1];
+    if(e1.has(Flag.NDT) || e1.has(Flag.UPD)) return cmp;
+
+    if(e2 instanceof RangeSeq) {
+      final RangeSeq rs = (RangeSeq) e2;
       return get(cmp, rs.start(), rs.end());
     }
-    if(e instanceof ANum) {
-      final double d = ((ANum) cmp.exprs[1]).dbl();
+    if(e2 instanceof ANum) {
+      final double d = ((ANum) e2).dbl();
       return get(cmp, d, d);
     }
     return cmp;
@@ -189,7 +191,7 @@
   private Stats key(final IndexInfo ii, final boolean text) {
     // statistics are not up-to-date
     final Data data = ii.ic.data;
-    if(!data.meta.uptodate || data.nspaces.size() != 0 || !(expr instanceof AxisPath)) return null;
+    if(!data.meta.uptodate || !data.nspaces.isEmpty() || !(expr instanceof AxisPath)) return null;
 
     NameTest test = ii.test;
     if(test == null) {
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/CmpSR.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/CmpSR.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/CmpSR.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/CmpSR.java	2015-07-14 10:54:40.000000000 +0000
@@ -73,14 +73,15 @@
    * @throws QueryException query exception
    */
   static ParseExpr get(final CmpG cmp) throws QueryException {
-    if(!(cmp.exprs[1] instanceof AStr)) return cmp;
-    final byte[] d = ((Item) cmp.exprs[1]).string(cmp.info);
-    final Expr e = cmp.exprs[0];
+    final Expr e1 = cmp.exprs[0], e2 = cmp.exprs[1];
+    if(e1.has(Flag.NDT) || e1.has(Flag.UPD) || !(e2 instanceof AStr)) return cmp;
+
+    final byte[] d = ((AStr) e2).string(cmp.info);
     switch(cmp.op.op) {
-      case GE: return new CmpSR(e, d,    true,  null, true,  cmp.coll, cmp.info);
-      case GT: return new CmpSR(e, d,    false, null, true,  cmp.coll, cmp.info);
-      case LE: return new CmpSR(e, null, true,  d,    true,  cmp.coll, cmp.info);
-      case LT: return new CmpSR(e, null, true,  d,    false, cmp.coll, cmp.info);
+      case GE: return new CmpSR(e1, d,    true,  null, true,  cmp.coll, cmp.info);
+      case GT: return new CmpSR(e1, d,    false, null, true,  cmp.coll, cmp.info);
+      case LE: return new CmpSR(e1, null, true,  d,    true,  cmp.coll, cmp.info);
+      case LT: return new CmpSR(e1, null, true,  d,    false, cmp.coll, cmp.info);
       default: return cmp;
     }
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/constr/Constr.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/constr/Constr.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/constr/Constr.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/constr/Constr.java	2015-07-14 10:54:40.000000000 +0000
@@ -2,8 +2,6 @@
 
 import static org.basex.query.QueryError.*;
 
-import java.util.*;
-
 import org.basex.query.*;
 import org.basex.query.expr.*;
 import org.basex.query.iter.*;
@@ -88,9 +86,8 @@
    */
   private boolean add(final QueryContext qc, final Item it) throws QueryException {
     if(it instanceof Array) {
-      final Iterator<Value> members = ((Array) it).members();
-      while(members.hasNext()) {
-        for(final Item i : members.next()) {
+      for(final Value val : ((Array) it).members()) {
+        for(final Item i : val) {
           if(!add(qc, i)) return false;
         }
       }
@@ -153,8 +150,8 @@
       } else if(ip == NodeType.DOC) {
         // type: document node
 
-        final AxisIter ai = node.children();
-        for(ANode ch; (ch = ai.next()) != null && add(qc, ch););
+        final BasicNodeIter iter = node.children();
+        for(ANode ch; (ch = iter.next()) != null && add(qc, ch););
 
       } else {
         // type: element/comment/processing instruction node
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/Context.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/Context.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/Context.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/Context.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,85 +0,0 @@
-package org.basex.query.expr;
-
-import org.basex.core.locks.*;
-import org.basex.query.*;
-import org.basex.query.iter.*;
-import org.basex.query.util.*;
-import org.basex.query.value.*;
-import org.basex.query.value.item.*;
-import org.basex.query.value.type.*;
-import org.basex.query.var.*;
-import org.basex.util.*;
-import org.basex.util.hash.*;
-
-/**
- * Context value.
- *
- * @author BaseX Team 2005-15, BSD License
- * @author Christian Gruen
- */
-public final class Context extends Simple {
-  /**
-   * Constructor.
-   * @param info input info
-   */
-  public Context(final InputInfo info) {
-    super(info);
-    seqType = SeqType.ITEM_ZM;
-  }
-
-  @Override
-  public Context compile(final QueryContext qc, final VarScope scp) {
-    return optimize(qc, scp);
-  }
-
-  @Override
-  public Context optimize(final QueryContext qc, final VarScope scp) {
-    if(qc.value != null) seqType = qc.value.seqType();
-    return this;
-  }
-
-  @Override
-  public Iter iter(final QueryContext qc) throws QueryException {
-    return ctxValue(qc).iter();
-  }
-
-  @Override
-  public Value value(final QueryContext qc) throws QueryException {
-    return ctxValue(qc);
-  }
-
-  @Override
-  public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
-    return ctxValue(qc).item(qc, info);
-  }
-
-  @Override
-  public boolean has(final Flag flag) {
-    return flag == Flag.CTX;
-  }
-
-  @Override
-  public boolean removable(final Var var) {
-    return false;
-  }
-
-  @Override
-  public Expr copy(final QueryContext qc, final VarScope scp, final IntObjMap<Var> vs) {
-    return copyType(new Context(info));
-  }
-
-  @Override
-  public boolean accept(final ASTVisitor visitor) {
-    return visitor.lock(DBLocking.CONTEXT) && super.accept(visitor);
-  }
-
-  @Override
-  public boolean sameAs(final Expr cmp) {
-    return cmp instanceof Context;
-  }
-
-  @Override
-  public String toString() {
-    return ".";
-  }
-}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/ContextValue.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/ContextValue.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/ContextValue.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/ContextValue.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,85 @@
+package org.basex.query.expr;
+
+import org.basex.core.locks.*;
+import org.basex.query.*;
+import org.basex.query.iter.*;
+import org.basex.query.util.*;
+import org.basex.query.value.*;
+import org.basex.query.value.item.*;
+import org.basex.query.value.type.*;
+import org.basex.query.var.*;
+import org.basex.util.*;
+import org.basex.util.hash.*;
+
+/**
+ * Context value.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Christian Gruen
+ */
+public final class ContextValue extends Simple {
+  /**
+   * Constructor.
+   * @param info input info
+   */
+  public ContextValue(final InputInfo info) {
+    super(info);
+    seqType = SeqType.ITEM_ZM;
+  }
+
+  @Override
+  public ContextValue compile(final QueryContext qc, final VarScope scp) {
+    return optimize(qc, scp);
+  }
+
+  @Override
+  public ContextValue optimize(final QueryContext qc, final VarScope scp) {
+    if(qc.value != null) seqType = qc.value.seqType();
+    return this;
+  }
+
+  @Override
+  public Iter iter(final QueryContext qc) throws QueryException {
+    return ctxValue(qc).iter();
+  }
+
+  @Override
+  public Value value(final QueryContext qc) throws QueryException {
+    return ctxValue(qc);
+  }
+
+  @Override
+  public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
+    return ctxValue(qc).item(qc, info);
+  }
+
+  @Override
+  public boolean has(final Flag flag) {
+    return flag == Flag.CTX;
+  }
+
+  @Override
+  public boolean removable(final Var var) {
+    return false;
+  }
+
+  @Override
+  public Expr copy(final QueryContext qc, final VarScope scp, final IntObjMap<Var> vs) {
+    return copyType(new ContextValue(info));
+  }
+
+  @Override
+  public boolean accept(final ASTVisitor visitor) {
+    return visitor.lock(DBLocking.CONTEXT) && super.accept(visitor);
+  }
+
+  @Override
+  public boolean sameAs(final Expr cmp) {
+    return cmp instanceof ContextValue;
+  }
+
+  @Override
+  public String toString() {
+    return ".";
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/DBPragma.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/DBPragma.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/DBPragma.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/DBPragma.java	2015-07-14 10:54:40.000000000 +0000
@@ -5,6 +5,7 @@
 
 import org.basex.core.*;
 import org.basex.query.*;
+import org.basex.query.expr.Expr.*;
 import org.basex.query.value.item.*;
 import org.basex.util.*;
 import org.basex.util.options.*;
@@ -23,13 +24,13 @@
 
   /**
    * Constructor.
-   * @param n name of pragma
-   * @param o option
-   * @param v optional value
+   * @param name name of pragma
+   * @param option option
+   * @param value optional value
    */
-  public DBPragma(final QNm n, final Option<?> o, final byte[] v) {
-    super(n, v);
-    option = o;
+  public DBPragma(final QNm name, final Option<?> option, final byte[] value) {
+    super(name, value);
+    this.option = option;
   }
 
   @Override
@@ -48,6 +49,11 @@
   }
 
   @Override
+  public boolean has(final Flag flag) {
+    return false;
+  }
+
+  @Override
   public Pragma copy() {
     return new DBPragma(name, option, value);
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/Except.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/Except.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/Except.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/Except.java	2015-07-14 10:54:40.000000000 +0000
@@ -56,21 +56,21 @@
   }
 
   @Override
-  protected NodeSeqBuilder eval(final Iter[] iter) throws QueryException {
-    final NodeSeqBuilder nc = new NodeSeqBuilder().check();
+  protected ANodeList eval(final Iter[] iter) throws QueryException {
+    final ANodeList list = new ANodeList().check();
 
-    for(Item it; (it = iter[0].next()) != null;) nc.add(toNode(it));
-    final boolean db = nc.dbnodes();
+    for(Item it; (it = iter[0].next()) != null;) list.add(toNode(it));
+    final boolean db = list.dbnodes();
 
     final int el = exprs.length;
-    for(int e = 1; e < el && nc.size() != 0; e++) {
+    for(int e = 1; e < el && !list.isEmpty(); e++) {
       final Iter ir = iter[e];
       for(Item it; (it = ir.next()) != null;) {
-        final int i = nc.indexOf(toNode(it), db);
-        if(i != -1) nc.delete(i);
+        final int i = list.indexOf(toNode(it), db);
+        if(i != -1) list.delete(i);
       }
     }
-    return nc;
+    return list;
   }
 
   @Override
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/Expr.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/Expr.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/Expr.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/Expr.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,7 +1,5 @@
 package org.basex.query.expr;
 
-import static org.basex.query.QueryText.*;
-
 import java.util.*;
 
 import org.basex.data.*;
@@ -34,7 +32,7 @@
     /** Creates new fragments. Example: node constructor. */ CNS,
     /** Depends on context. Example: context node. */        CTX,
     /** Non-deterministic. Example: random:double(). */      NDT,
-    /** Focus-dependent. Example: position(). */             FCS,
+    /** Positional access. Example: position(). */           POS,
     /** Performs updates. Example: insert expression. */     UPD,
     /** Invokes user-supplied functions. Example: fold. */   HOF,
   }
@@ -180,8 +178,8 @@
   }
 
   /**
-   * Returns the data reference bound to this expression. This method is overwritten
-   * by the values {@link DBNode} and {@link DBNodeSeq} and some more expressions.
+   * Returns the data reference bound to this expression. This method is currently overwritten
+   * by {@link DBNode}, {@link DBNodeSeq}, {@link Path} and {@link VarRef}.
    * @return data reference
    */
   public Data data() {
@@ -198,7 +196,7 @@
    * Indicates if an expression has the specified compiler property. This method must only be
    * called at compile time. It is invoked to test properties of sub-expressions.
    * It returns {@code true} if at least one test is successful.
-   * @param flag flag to be found
+   * @param flag flag to be checked
    * @return result of check
    */
   public abstract boolean has(final Flag flag);
@@ -310,7 +308,7 @@
     // return true if a deterministic expression returns at least one node
     final SeqType st = seqType();
     if(st.type instanceof NodeType && st.occ.min >= 1 && !has(Flag.UPD) && !has(Flag.NDT)) {
-      qc.compInfo(OPTWRITE, this);
+      qc.compInfo(QueryText.OPTWRITE, this);
       return Bln.TRUE;
     }
     return this;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/Extension.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/Extension.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/Extension.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/Extension.java	2015-07-14 10:54:40.000000000 +0000
@@ -83,6 +83,12 @@
   }
 
   @Override
+  public boolean has(final Flag flag) {
+    for(final Pragma p : pragmas) if(p.has(flag)) return true;
+    return super.has(flag);
+  }
+
+  @Override
   public String toString() {
     final StringBuilder sb = new StringBuilder();
     for(final Pragma p : pragmas) sb.append(p).append(' ');
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/Filter.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/Filter.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/Filter.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/Filter.java	2015-07-14 10:54:40.000000000 +0000
@@ -6,10 +6,10 @@
 import org.basex.query.expr.gflwor.*;
 import org.basex.query.expr.path.*;
 import org.basex.query.func.*;
+import org.basex.query.func.fn.*;
 import org.basex.query.util.*;
 import org.basex.query.value.*;
 import org.basex.query.value.item.*;
-import org.basex.query.value.seq.*;
 import org.basex.query.var.*;
 import org.basex.util.*;
 
@@ -55,11 +55,11 @@
   private static Expr path(final Expr root, final Expr... preds) {
     // no predicates: return root
     if(preds.length == 0) return root;
-    // axis path
+    // axis path: attach predicates to last step
     if(root instanceof AxisPath) {
-      // predicate must not be numeric
+      // predicates must not be numeric: (//x)[1] != //x[1]
       for(final Expr pred : preds) {
-        if(pred.seqType().mayBeNumber() || pred.has(Flag.FCS)) return null;
+        if(pred.seqType().mayBeNumber() || pred.has(Flag.POS)) return null;
       }
       return ((AxisPath) root).addPreds(preds);
     }
@@ -131,14 +131,14 @@
     if(ex != null) return ex.optimize(qc, scp);
 
     // try to rewrite filter to index access
-    if(root instanceof Context || root instanceof Value && root.data() != null) {
+    if(root instanceof ContextValue || root instanceof Value && root.data() != null) {
       final Path ip = Path.get(info, root, Step.get(info, SELF, Test.NOD, preds));
       final Expr ie = ip.index(qc, Path.initial(qc, root));
       if(ie != ip) return ie;
     }
 
     // no numeric predicates.. use simple iterator
-    if(!super.has(Flag.FCS)) return copyType(new IterFilter(info, root, preds));
+    if(!super.has(Flag.POS)) return copyType(new IterFilter(info, root, preds));
 
     // evaluate positional predicates
     Expr e = root;
@@ -152,7 +152,7 @@
       if(last) {
         if(e.isValue()) {
           // return sub-sequence
-          e = SubSeq.get((Value) e, e.size() - 1, 1);
+          e = FnSubsequence.eval((Value) e, e.size(), 1);
         } else {
           // rewrite positional predicate to basex:last-from
           e = Function._BASEX_LAST_FROM.get(null, info, e);
@@ -161,7 +161,7 @@
       } else if(pos != null) {
         if(e.isValue()) {
           // return sub-sequence
-          e = SubSeq.get((Value) e, pos.min - 1, pos.max - pos.min + 1);
+          e = FnSubsequence.eval((Value) e, pos.min, pos.max - pos.min + 1);
         } else if(pos.min == pos.max) {
           // example: expr[pos] -> basex:item-at(expr, pos.min)
           e = Function._BASEX_ITEM_AT.get(null, info, e, Int.get(pos.min));
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/ft/FTAnd.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/ft/FTAnd.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/ft/FTAnd.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/ft/FTAnd.java	2015-07-14 10:54:40.000000000 +0000
@@ -2,11 +2,11 @@
 
 import static org.basex.query.QueryText.*;
 
-import org.basex.data.*;
 import org.basex.query.*;
 import org.basex.query.expr.*;
 import org.basex.query.iter.*;
 import org.basex.query.util.*;
+import org.basex.query.util.ft.*;
 import org.basex.query.value.node.*;
 import org.basex.query.var.*;
 import org.basex.util.*;
@@ -77,7 +77,7 @@
             return null;
           }
 
-          final int d = it[0].pre - it[i].pre;
+          final int d = it[0].pre() - it[i].pre();
           if(negated[i]) {
             if(d >= 0) {
               if(d == 0) it[0] = ir[0].next();
@@ -113,14 +113,14 @@
    * @param i2 second item
    */
   private static void and(final FTNode i1, final FTNode i2) {
-    final FTMatches all = new FTMatches((byte) Math.max(i1.all.pos, i2.all.pos));
-    for(final FTMatch s1 : i1.all) {
-      for(final FTMatch s2 : i2.all) {
+    final FTMatches all = new FTMatches((byte) Math.max(i1.matches().pos, i2.matches().pos));
+    for(final FTMatch s1 : i1.matches()) {
+      for(final FTMatch s2 : i2.matches()) {
         all.add(new FTMatch(s1.size() + s2.size()).add(s1).add(s2));
       }
     }
     i1.score(Scoring.avg(i1.score() + i2.score(), 2));
-    i1.all = all;
+    i1.matches(all);
   }
 
   @Override
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/ft/FTContains.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/ft/FTContains.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/ft/FTContains.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/ft/FTContains.java	2015-07-14 10:54:40.000000000 +0000
@@ -2,11 +2,11 @@
 
 import static org.basex.query.QueryText.*;
 
-import org.basex.data.*;
 import org.basex.query.*;
 import org.basex.query.expr.*;
 import org.basex.query.iter.*;
 import org.basex.query.util.*;
+import org.basex.query.util.ft.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.node.*;
 import org.basex.query.value.type.*;
@@ -54,13 +54,14 @@
     for(Item it; (it = iter.next()) != null;) {
       lex.init(it.string(info));
       final FTNode item = ftexpr.item(qc, info);
-      if(item.all.matches()) {
+      final FTMatches all = item.matches();
+      if(all.matches()) {
         f = true;
         if(scoring) s += item.score();
         // cache entry for visualizations or ft:mark/ft:extract
         if(ftPosData != null && it instanceof DBNode) {
           final DBNode node = (DBNode) it;
-          ftPosData.add(node.data, node.pre, item.all);
+          ftPosData.add(node.data(), node.pre(), all);
         }
       }
       c++;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/ft/FTContent.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/ft/FTContent.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/ft/FTContent.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/ft/FTContent.java	2015-07-14 10:54:40.000000000 +0000
@@ -2,8 +2,8 @@
 
 import static org.basex.query.QueryText.*;
 
-import org.basex.data.*;
 import org.basex.query.*;
+import org.basex.query.util.ft.*;
 import org.basex.query.value.node.*;
 import org.basex.query.var.*;
 import org.basex.util.*;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/ft/FTDistance.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/ft/FTDistance.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/ft/FTDistance.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/ft/FTDistance.java	2015-07-14 10:54:40.000000000 +0000
@@ -2,10 +2,10 @@
 
 import static org.basex.query.QueryText.*;
 
-import org.basex.data.*;
 import org.basex.query.*;
 import org.basex.query.expr.*;
 import org.basex.query.util.*;
+import org.basex.query.util.ft.*;
 import org.basex.query.value.node.*;
 import org.basex.query.var.*;
 import org.basex.util.*;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/ft/FTFilter.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/ft/FTFilter.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/ft/FTFilter.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/ft/FTFilter.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,9 +1,9 @@
 package org.basex.query.expr.ft;
 
-import org.basex.data.*;
 import org.basex.query.*;
 import org.basex.query.iter.*;
 import org.basex.query.util.*;
+import org.basex.query.util.ft.*;
 import org.basex.query.value.node.*;
 import org.basex.util.*;
 import org.basex.util.ft.*;
@@ -71,7 +71,7 @@
   private boolean filter(final QueryContext qc, final FTNode item, final FTLexer lex)
       throws QueryException {
 
-    final FTMatches all = item.all;
+    final FTMatches all = item.matches();
     for(int a = 0; a < all.size(); a++) {
       if(!filter(qc, all.match[a], lex)) all.delete(a--);
     }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/ft/FTIndexAccess.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/ft/FTIndexAccess.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/ft/FTIndexAccess.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/ft/FTIndexAccess.java	2015-07-14 10:54:40.000000000 +0000
@@ -50,9 +50,9 @@
           // assign scoring
           if(qc.scoring) it.score();
           // cache entry for visualizations or ft:mark/ft:extract
-          if(qc.ftPosData != null) qc.ftPosData.add(it.data, it.pre, it.all);
+          if(qc.ftPosData != null) qc.ftPosData.add(it.data(), it.pre(), it.matches());
           // remove matches reference to save memory
-          it.all = null;
+          it.matches(null);
         }
         return it;
       }
@@ -110,7 +110,7 @@
     Expr e = ftexpr;
     if(ftexpr instanceof FTWords) {
       final FTWords f = (FTWords) ftexpr;
-      if(f.mode == FTMode.ANY && f.occ == null) e = f.query;
+      if(f.mode == FTMode.ANY && f.occ == null && f.ftt == null) e = f.query;
     }
     return Function._FT_SEARCH.get(null, info, Str.get(ictx.data.meta.name), e).toString();
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/ft/FTMildNot.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/ft/FTMildNot.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/ft/FTMildNot.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/ft/FTMildNot.java	2015-07-14 10:54:40.000000000 +0000
@@ -3,10 +3,10 @@
 import static org.basex.query.QueryError.*;
 import static org.basex.query.QueryText.*;
 
-import org.basex.data.*;
 import org.basex.query.*;
 import org.basex.query.iter.*;
 import org.basex.query.util.*;
+import org.basex.query.util.ft.*;
 import org.basex.query.value.node.*;
 import org.basex.query.var.*;
 import org.basex.util.*;
@@ -48,13 +48,13 @@
       @Override
       public FTNode next() throws QueryException {
         while(it1 != null && it2 != null) {
-          final int d = it1.pre - it2.pre;
+          final int d = it1.pre() - it2.pre();
           if(d < 0) break;
 
           if(d > 0) {
             it2 = i2.next();
           } else {
-            if(!mildnot(it1, it2).all.isEmpty()) break;
+            if(!mildnot(it1, it2).matches().isEmpty()) break;
             it1 = i1.next();
           }
         }
@@ -72,7 +72,7 @@
    * @return specified item
    */
   private static FTNode mildnot(final FTNode it1, final FTNode it2) {
-    it1.all = mildnot(it1.all, it2.all);
+    it1.matches(mildnot(it1.matches(), it2.matches()));
     return it1;
   }
 
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/ft/FTNot.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/ft/FTNot.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/ft/FTNot.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/ft/FTNot.java	2015-07-14 10:54:40.000000000 +0000
@@ -2,10 +2,10 @@
 
 import static org.basex.query.QueryText.*;
 
-import org.basex.data.*;
 import org.basex.query.*;
 import org.basex.query.iter.*;
 import org.basex.query.util.*;
+import org.basex.query.util.ft.*;
 import org.basex.query.value.node.*;
 import org.basex.query.var.*;
 import org.basex.util.*;
@@ -59,7 +59,7 @@
    */
   private static FTNode not(final FTNode item) {
     if(item != null) {
-      item.all = not(item.all);
+      item.matches(not(item.matches()));
       item.score(Scoring.not(item.score()));
     }
     return item;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/ft/FTOrder.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/ft/FTOrder.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/ft/FTOrder.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/ft/FTOrder.java	2015-07-14 10:54:40.000000000 +0000
@@ -2,8 +2,8 @@
 
 import static org.basex.util.Token.*;
 
-import org.basex.data.*;
 import org.basex.query.*;
+import org.basex.query.util.ft.*;
 import org.basex.query.value.node.*;
 import org.basex.query.var.*;
 import org.basex.util.*;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/ft/FTOr.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/ft/FTOr.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/ft/FTOr.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/ft/FTOr.java	2015-07-14 10:54:40.000000000 +0000
@@ -2,11 +2,11 @@
 
 import static org.basex.query.QueryText.*;
 
-import org.basex.data.*;
 import org.basex.query.*;
 import org.basex.query.expr.*;
 import org.basex.query.iter.*;
 import org.basex.query.util.*;
+import org.basex.query.util.ft.*;
 import org.basex.query.value.node.*;
 import org.basex.query.var.*;
 import org.basex.util.*;
@@ -71,7 +71,7 @@
         // find item with smallest pre value
         int p = -1;
         for(int i = 0; i < es; ++i) {
-          if(it[i] != null && (p == -1 || it[p].pre > it[i].pre)) p = i;
+          if(it[i] != null && (p == -1 || it[p].pre() > it[i].pre())) p = i;
         }
         // no items left - leave
         if(p == -1) return null;
@@ -79,7 +79,7 @@
         // merge all matches
         final FTNode item = it[p];
         for(int i = 0; i < es; ++i) {
-          if(it[i] != null && p != i && item.pre == it[i].pre) {
+          if(it[i] != null && p != i && item.pre() == it[i].pre()) {
             or(item, it[i]);
             it[i] = ir[i].next();
           }
@@ -96,11 +96,12 @@
    * @param i2 second item
    */
   private static void or(final FTNode i1, final FTNode i2) {
-    final FTMatches all = new FTMatches((byte) Math.max(i1.all.pos, i2.all.pos));
-    for(final FTMatch m : i1.all) all.add(m);
-    for(final FTMatch m : i2.all) all.add(m);
+    final FTMatches all1 = i1.matches(), all2 = i2.matches();
+    final FTMatches all = new FTMatches((byte) Math.max(all1.pos, all2.pos));
+    for(final FTMatch m : all1) all.add(m);
+    for(final FTMatch m : all2) all.add(m);
     i1.score(Scoring.avg(i1.score() + i2.score(), 2));
-    i1.all = all;
+    i1.matches(all);
   }
 
   @Override
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/ft/FTScope.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/ft/FTScope.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/ft/FTScope.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/ft/FTScope.java	2015-07-14 10:54:40.000000000 +0000
@@ -2,8 +2,8 @@
 
 import static org.basex.query.QueryText.*;
 
-import org.basex.data.*;
 import org.basex.query.*;
+import org.basex.query.util.ft.*;
 import org.basex.query.value.node.*;
 import org.basex.query.var.*;
 import org.basex.util.*;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/ft/FTWeight.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/ft/FTWeight.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/ft/FTWeight.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/ft/FTWeight.java	2015-07-14 10:54:40.000000000 +0000
@@ -73,7 +73,7 @@
     if(item == null) return null;
     final double d = toDouble(weight, qc);
     if(Math.abs(d) > 1000) throw FTWEIGHT_X.get(info, d);
-    if(d == 0) item.all.size(0);
+    if(d == 0) item.matches().reset();
     item.score(item.score() * d);
     return item;
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/ft/FTWindow.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/ft/FTWindow.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/ft/FTWindow.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/ft/FTWindow.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,9 +1,9 @@
 package org.basex.query.expr.ft;
 
-import org.basex.data.*;
 import org.basex.query.*;
 import org.basex.query.expr.*;
 import org.basex.query.util.*;
+import org.basex.query.util.ft.*;
 import org.basex.query.value.node.*;
 import org.basex.query.var.*;
 import org.basex.util.*;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/ft/FTWords.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/ft/FTWords.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/ft/FTWords.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/ft/FTWords.java	2015-07-14 10:54:40.000000000 +0000
@@ -10,6 +10,7 @@
 import org.basex.query.expr.*;
 import org.basex.query.iter.*;
 import org.basex.query.util.*;
+import org.basex.query.util.ft.*;
 import org.basex.query.value.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.node.*;
@@ -36,9 +37,9 @@
   Expr query;
   /** Minimum and maximum occurrences. */
   Expr[] occ;
-
   /** Full-text tokenizer. */
-  private FTTokenizer ftt;
+  FTTokenizer ftt;
+
   /** Data reference. */
   private Data data;
   /** Statically evaluated query tokens. */
@@ -349,15 +350,15 @@
        fto.isSet(ST) && md.stemming != fto.is(ST) ||
        fto.ln != null && !fto.ln.equals(md.language)) return false;
 
+    // adopt database options to tokenizer
+    fto.copy(md);
+
     // estimate costs if text is not known at compile time
     if(tokens == null) {
       ii.costs = Math.max(2, data.meta.size / 30);
       return true;
     }
 
-    // adopt database options to tokenizer
-    fto.copy(md);
-
     // summarize number of hits; break loop if no hits are expected
     final FTLexer ft = new FTLexer(fto);
     ii.costs = 0;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/gflwor/For.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/gflwor/For.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/gflwor/For.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/gflwor/For.java	2015-07-14 10:54:40.000000000 +0000
@@ -208,7 +208,7 @@
     try {
       qc.value = null;
       // assign type of iterated items to context expression
-      final Context c = new Context(info);
+      final ContextValue c = new ContextValue(info);
       c.seqType(expr.seqType().type.seqType());
       final Expr r = ex.inline(qc, scp, var, c);
       if(r != null) pred = r;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/gflwor/GFLWOR.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/gflwor/GFLWOR.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/gflwor/GFLWOR.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/gflwor/GFLWOR.java	2015-07-14 10:54:40.000000000 +0000
@@ -42,37 +42,58 @@
     this.ret = ret;
   }
 
+  /**
+   * Creates a new evaluator for this FLWOR expression.
+   * @return the evaluator
+   */
+  private Eval newEval() {
+    Eval e = new StartEval();
+    for(final Clause cls : clauses) e = cls.eval(e);
+    return e;
+  }
+
   @Override
-  public Iter iter(final QueryContext qc) {
-    // Start evaluator, doing nothing, once.
-    Eval e = new Eval() {
-      /** First-evaluation flag. */
-      private boolean first = true;
-      @Override
-      public boolean next(final QueryContext q) {
-        if(!first) return false;
-        first = false;
-        return true;
+  public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
+    Item out = null;
+    for(final Eval eval = newEval(); eval.next(qc);) {
+      final Item it = ret.item(qc, ii);
+      if(it != null) {
+        if(out != null) throw QueryError.SEQFOUND_X.get(ii, ValueBuilder.concat(out, it));
+        out = it;
       }
-    };
+    }
+    return out;
+  }
 
-    for(final Clause cls : clauses) e = cls.eval(e);
-    final Eval ev = e;
+  @Override
+  public Value value(final QueryContext qc) throws QueryException {
+    final Eval eval = newEval();
+    if(!eval.next(qc)) return Empty.SEQ;
+    final Value v1 = ret.value(qc);
+    if(!eval.next(qc)) return v1;
+
+    final ValueBuilder vb = new ValueBuilder().add(v1);
+    do {
+      vb.add(ret.value(qc));
+    } while(eval.next(qc));
+    return vb.value();
+  }
 
+  @Override
+  public Iter iter(final QueryContext qc) {
     return new Iter() {
+      /** Clause evaluator. */
+      private final Eval ev = newEval();
       /** Return iterator. */
       private Iter sub = Empty.ITER;
-      /** If the iterator has been emptied. */
-      private boolean drained;
       @Override
       public Item next() throws QueryException {
-        if(drained) return null;
-        while(true) {
+        for(;;) {
           final Item it = sub.next();
           qc.checkStop();
           if(it != null) return it;
           if(!ev.next(qc)) {
-            drained = true;
+            sub = null;
             return null;
           }
           sub = ret.iter(qc);
@@ -83,22 +104,25 @@
 
   @Override
   public Expr compile(final QueryContext qc, final VarScope scp) throws QueryException {
-    int i = 0;
+    final ListIterator<Clause> iter = clauses.listIterator();
+    try {
+      while(iter.hasNext()) iter.next().compile(qc, scp);
+    } catch(final QueryException qe) {
+      iter.remove();
+      clauseError(qe, iter);
+    }
+
     try {
-      for(final Clause clause : clauses) {
-        clause.compile(qc, scp);
-        i++;
-      }
       ret = ret.compile(qc, scp);
     } catch(final QueryException qe) {
-      clauseError(qe, i);
+      clauseError(qe, iter);
     }
+
     return optimize(qc, scp);
   }
 
   @Override
   public Expr optimize(final QueryContext qc, final VarScope scp) throws QueryException {
-    // split combined where clauses
     final ListIterator<Clause> iter = clauses.listIterator();
     while(iter.hasNext()) {
       final Clause clause = iter.next();
@@ -352,8 +376,8 @@
             || expr instanceof AxisPath && ((AxisPath) expr).cheap()) {
 
             qc.compInfo(QueryText.OPTINLINE, lt.var);
-            inline(qc, scp, lt.var, lt.inlineExpr(qc, scp), next);
-            iter.remove();
+            inline(qc, scp, lt.var, lt.inlineExpr(qc, scp), iter);
+            clauses.remove(lt);
             changing = changed = true;
             // continue from the beginning as clauses below could have been deleted
             break;
@@ -668,7 +692,7 @@
   @Override
   public Expr inline(final QueryContext qc, final VarScope scp, final Var var, final Expr ex)
       throws QueryException {
-    return inline(qc, scp, var, ex, 0) ? optimize(qc, scp) : null;
+    return inline(qc, scp, var, ex, clauses.listIterator()) ? optimize(qc, scp) : null;
   }
 
   /**
@@ -677,15 +701,14 @@
    * @param scp variable scope
    * @param var variable
    * @param ex expression to inline
-   * @param pos clause position
+   * @param iter iterator at the position of the first clause to inline into
    * @return if changes occurred
    * @throws QueryException query exception
    */
   private boolean inline(final QueryContext qc, final VarScope scp, final Var var, final Expr ex,
-      final int pos) throws QueryException {
+      final ListIterator<Clause> iter) throws QueryException {
 
     boolean changed = false;
-    final ListIterator<Clause> iter = clauses.listIterator(pos);
     while(iter.hasNext()) {
       final Clause clause = iter.next();
       try {
@@ -695,7 +718,8 @@
           iter.set(cl);
         }
       } catch(final QueryException qe) {
-        return clauseError(qe, iter.previousIndex() + 1);
+        iter.remove();
+        return clauseError(qe, iter);
       }
     }
 
@@ -706,7 +730,7 @@
         ret = rt;
       }
     } catch(final QueryException qe) {
-      return clauseError(qe, clauses.size());
+      return clauseError(qe, iter);
     }
 
     return changed;
@@ -715,12 +739,13 @@
   /**
    * Tries to recover from a compile-time exception inside a FLWOR clause.
    * @param qe thrown exception
-   * @param idx index of the throwing clause, size of {@link #clauses} for return clause
+   * @param iter iterator positioned where the failing clause was before
    * @return {@code true} if the GFLWOR expression has to stay
    * @throws QueryException query exception if the whole expression fails
    */
-  private boolean clauseError(final QueryException qe, final int idx) throws QueryException {
-    final ListIterator<Clause> iter = clauses.listIterator(idx);
+  private boolean clauseError(final QueryException qe, final ListIterator<Clause> iter)
+      throws QueryException {
+    // check if an outer clause can prevent the error
     while(iter.hasPrevious()) {
       final Clause b4 = iter.previous();
       if(b4 instanceof For || b4 instanceof Window || b4 instanceof Where) {
@@ -733,6 +758,8 @@
         return true;
       }
     }
+
+    // error will always be thrown
     throw qe;
   }
 
@@ -811,7 +838,7 @@
    * @author BaseX Team 2005-15, BSD License
    * @author Leo Woerteler
    */
-  interface Eval {
+  abstract static class Eval {
     /**
      * Makes the next evaluation step if available. This method is guaranteed
      * to not be called again if it has once returned {@code false}.
@@ -819,7 +846,19 @@
      * @return {@code true} if step was made, {@code false} if no more results exist
      * @throws QueryException evaluation exception
      */
-    boolean next(final QueryContext qc) throws QueryException;
+    abstract boolean next(final QueryContext qc) throws QueryException;
+  }
+
+  /** Start evaluator, doing nothing, once. */
+  private static final class StartEval extends Eval {
+    /** First-evaluation flag. */
+    private boolean first = true;
+    @Override
+    public boolean next(final QueryContext q) {
+      if(!first) return false;
+      first = false;
+      return true;
+    }
   }
 
   /**
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/gflwor/GroupBy.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/gflwor/GroupBy.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/gflwor/GroupBy.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/gflwor/GroupBy.java	2015-07-14 10:54:40.000000000 +0000
@@ -8,9 +8,9 @@
 import org.basex.query.expr.*;
 import org.basex.query.expr.gflwor.GFLWOR.Clause;
 import org.basex.query.expr.gflwor.GFLWOR.Eval;
-import org.basex.query.iter.*;
 import org.basex.query.util.*;
 import org.basex.query.util.collation.*;
+import org.basex.query.value.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.node.*;
 import org.basex.query.value.seq.*;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/gflwor/Let.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/gflwor/Let.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/gflwor/Let.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/gflwor/Let.java	2015-07-14 10:54:40.000000000 +0000
@@ -152,7 +152,7 @@
   }
 
   /** Evaluator for a block of {@code let} expressions. */
-  private static class LetEval implements Eval {
+  private static class LetEval extends Eval {
     /** Let expressions of the current block, in declaration order. */
     private final ArrayList<Let> lets;
     /** Sub-evaluator. */
@@ -170,7 +170,7 @@
     }
 
     @Override
-    public boolean next(final QueryContext qc) throws QueryException {
+    boolean next(final QueryContext qc) throws QueryException {
       if(!sub.next(qc)) return false;
 
       for(final Let let : lets) {
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/gflwor/Window.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/gflwor/Window.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/gflwor/Window.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/gflwor/Window.java	2015-07-14 10:54:40.000000000 +0000
@@ -12,6 +12,7 @@
 import org.basex.query.expr.gflwor.GFLWOR.Eval;
 import org.basex.query.iter.*;
 import org.basex.query.util.*;
+import org.basex.query.value.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.node.*;
 import org.basex.query.value.seq.*;
@@ -117,8 +118,7 @@
 
           // find end item
           if(fst != null) {
-            final ValueBuilder window = new ValueBuilder(
-                new Item[] {fst, null, null, null}, 1);
+            final ValueBuilder window = new ValueBuilder().add(fst);
             final Item[] st = vals == null ? new Item[] { curr, prev, next } : vals;
             final long ps = vals == null ? p : spos;
             vals = null;
@@ -343,8 +343,9 @@
 
   @Override
   void calcSize(final long[] minMax) {
+    // number of results cannot be anticipated
     minMax[0] = 0;
-    if(expr.isEmpty()) minMax[1] = 0;
+    minMax[1] = expr.isEmpty() ? 0 : -1;
   }
 
   @Override
@@ -542,7 +543,7 @@
    * @author BaseX Team 2005-15, BSD License
    * @author Leo Woerteler
    */
-  private abstract class WindowEval implements Eval {
+  private abstract class WindowEval extends Eval {
     /** Expression iterator. */
     private Iter iter;
     /** Previous item. */
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/IndexAccess.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/IndexAccess.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/IndexAccess.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/IndexAccess.java	2015-07-14 10:54:40.000000000 +0000
@@ -13,7 +13,7 @@
  */
 public abstract class IndexAccess extends Simple {
   /** Index context. */
-  public final IndexContext ictx;
+  final IndexContext ictx;
 
   /**
    * Constructor.
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/InterSect.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/InterSect.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/InterSect.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/InterSect.java	2015-07-14 10:54:40.000000000 +0000
@@ -2,6 +2,7 @@
 
 import org.basex.query.*;
 import org.basex.query.iter.*;
+import org.basex.query.util.list.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.node.*;
 import org.basex.query.var.*;
@@ -31,24 +32,24 @@
   }
 
   @Override
-  protected NodeSeqBuilder eval(final Iter[] iter) throws QueryException {
-    NodeSeqBuilder nc = new NodeSeqBuilder();
+  protected ANodeList eval(final Iter[] iter) throws QueryException {
+    ANodeList list = new ANodeList();
 
-    for(Item it; (it = iter[0].next()) != null;) nc.add(toNode(it));
-    final boolean db = nc.dbnodes();
+    for(Item it; (it = iter[0].next()) != null;) list.add(toNode(it));
+    final boolean db = list.dbnodes();
 
     final int el = exprs.length;
-    for(int e = 1; e < el && nc.size() != 0; ++e) {
-      final NodeSeqBuilder nt = new NodeSeqBuilder().check();
+    for(int e = 1; e < el && list.size() != 0; ++e) {
+      final ANodeList nt = new ANodeList().check();
       final Iter ir = iter[e];
       for(Item it; (it = ir.next()) != null;) {
         final ANode n = toNode(it);
-        final int i = nc.indexOf(n, db);
+        final int i = list.indexOf(n, db);
         if(i != -1) nt.add(n);
       }
-      nc = nt;
+      list = nt;
     }
-    return nc;
+    return list;
   }
 
   @Override
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/List.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/List.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/List.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/List.java	2015-07-14 10:54:40.000000000 +0000
@@ -21,7 +21,7 @@
  */
 public final class List extends Arr {
   /** Limit for the size of sequences that are materialized at compile time. */
-  private static final int MAX_MAT_SIZE = 1 << 20;
+  private static final int MAX_MAT_SIZE = 1 << 16;
   /**
    * Constructor.
    * @param info input info
@@ -45,6 +45,20 @@
 
   @Override
   public Expr optimize(final QueryContext qc, final VarScope scp) throws QueryException {
+    // remove empty sequences
+    int p = 0;
+    for(final Expr e : exprs) {
+      if(!e.isEmpty()) exprs[p++] = e;
+    }
+
+    if(p != exprs.length) {
+      qc.compInfo(OPTREMOVE, this, Empty.SEQ);
+      if(p < 2) return p == 0 ? Empty.SEQ : exprs[0];
+      final Expr[] es = new Expr[p];
+      System.arraycopy(exprs, 0, es, 0, p);
+      exprs = es;
+    }
+
     // compute number of results
     size = 0;
     boolean ne = false;
@@ -60,7 +74,6 @@
     }
 
     if(size >= 0) {
-      if(size == 0 && !has(Flag.NDT) && !has(Flag.UPD)) return optPre(qc);
       if(allAreValues() && size <= MAX_MAT_SIZE) {
         Type all = null;
         final Value[] vs = new Value[exprs.length];
@@ -83,7 +96,7 @@
         else if(all != null && all.instanceOf(AtomType.ITR)) {
           val = IntSeq.get(vs, s, all);
         } else {
-          final ValueBuilder vb = new ValueBuilder(s);
+          final ValueBuilder vb = new ValueBuilder();
           for(int i = 0; i < c; i++) vb.add(vs[i]);
           val = vb.value();
         }
@@ -129,6 +142,8 @@
 
   @Override
   public Value value(final QueryContext qc) throws QueryException {
+    // most common case
+    if(exprs.length == 2) return ValueBuilder.concat(qc.value(exprs[0]), qc.value(exprs[1]));
     final ValueBuilder vb = new ValueBuilder();
     for(final Expr e : exprs) vb.add(qc.value(e));
     return vb.value();
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/Lookup.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/Lookup.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/Lookup.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/Lookup.java	2015-07-14 10:54:40.000000000 +0000
@@ -5,11 +5,15 @@
 import java.util.*;
 
 import org.basex.query.*;
+import org.basex.query.expr.gflwor.*;
+import org.basex.query.func.*;
 import org.basex.query.iter.*;
 import org.basex.query.value.*;
 import org.basex.query.value.array.Array;
 import org.basex.query.value.item.*;
 import org.basex.query.value.map.Map;
+import org.basex.query.value.seq.*;
+import org.basex.query.value.type.*;
 import org.basex.query.var.*;
 import org.basex.util.*;
 import org.basex.util.hash.*;
@@ -21,13 +25,18 @@
  * @author Christian Gruen
  */
 public final class Lookup extends Arr {
+  /** Static context. */
+  private final StaticContext sc;
+
   /**
    * Constructor.
    * @param info input info
+   * @param sc static context
    * @param expr expression and optional context
    */
-  public Lookup(final InputInfo info, final Expr... expr) {
+  public Lookup(final InputInfo info, final StaticContext sc, final Expr... expr) {
     super(info, expr);
+    this.sc = sc;
   }
 
   @Override
@@ -38,31 +47,115 @@
 
   @Override
   public Expr optimize(final QueryContext qc, final VarScope scp) throws QueryException {
-    return exprs.length > 1 && (exprs[1] instanceof Map || exprs[1] instanceof Array) &&
-        exprs[0].isValue() ? optPre(value(qc), qc) : this;
+    if(exprs.length != 2) return this;
+
+    final Expr ks = exprs[0], fs = exprs[1];
+    if(ks.isValue() && (fs instanceof Map || fs instanceof Array)) {
+      // guaranteed to be fully evaluated
+      return optPre(value(qc), qc);
+    }
+
+    final Type tp = fs.seqType().type;
+    if(!(tp instanceof ArrayType || tp instanceof MapType)) return this;
+
+    if(ks != Str.WC) {
+      if(fs.size() == 1 || fs.seqType().one()) {
+        // one function, rewrite to for-each or function call
+        final Expr opt = ks.size() == 1 || ks.seqType().one()
+            ? new DynFuncCall(info, sc, false, fs, ks) : Function.FOR_EACH.get(sc, info, exprs);
+        return optPre(opt, qc).optimize(qc, scp);
+      }
+
+      if(ks.isValue()) {
+        // keys are constant, so we do not duplicate work in the inner loop
+        final LinkedList<GFLWOR.Clause> clauses = new LinkedList<>();
+        final Var f = scp.newLocal(qc, QNm.get("f"), null, false);
+        clauses.add(new For(f, null, null, fs, false, info));
+        final Var k = scp.newLocal(qc, QNm.get("k"), null, false);
+        clauses.add(new For(k, null, null, ks, false, info));
+        final VarRef rf = new VarRef(info, f), rk = new VarRef(info, k);
+        final DynFuncCall ret = new DynFuncCall(info, sc, false, rf, rk);
+        return optPre(new GFLWOR(info, clauses, ret), qc).optimize(qc, scp);
+      }
+    }
+
+    return this;
+  }
+
+  @Override
+  public Iter iter(final QueryContext qc) throws QueryException {
+    return value(qc).iter();
   }
 
   @Override
-  public ValueIter iter(final QueryContext qc) throws QueryException {
+  public Value value(final QueryContext qc) throws QueryException {
+    if(exprs[0] == Str.WC) return wildCard(qc);
+    if(exprs[0] instanceof Item) return lookup((Item) exprs[0], qc);
+
     final ValueBuilder vb = new ValueBuilder();
-    for(final Item ctx : exprs.length == 1 ? ctxValue(qc) : qc.value(exprs[1])) {
-      final boolean map = ctx instanceof Map, array = ctx instanceof Array;
-      if(!map && !array) throw LOOKUP_X.get(info, ctx);
+    final Iter iter = exprs.length == 1 ? ctxValue(qc).iter() : qc.iter(exprs[1]);
+    for(Item ctx; (ctx = iter.next()) != null;) {
+      final Iter keys = exprs[0].iter(qc);
+      final FItem f = mapOrArray(ctx);
+      for(Item k; (k = keys.next()) != null;) vb.add(f.invokeValue(qc, info, k));
+    }
+    return vb.value();
+  }
 
-      final FItem f = (FItem) ctx;
-      if(exprs[0] == Str.WC) {
-        if(map) {
-          for(final Value v : ((Map) f).values()) vb.add(v);
-        } else {
-          final Iterator<Value> iter = ((Array) f).members();
-          while(iter.hasNext()) vb.add(iter.next());
-        }
+  /**
+   * Checks if the given item is either a map or an array.
+   * @param it item to check
+   * @return cast item if check succeeded
+   * @throws QueryException if the item is neither a map nor an array
+   */
+  private FItem mapOrArray(final Item it) throws QueryException {
+    final boolean map = it instanceof Map, array = it instanceof Array;
+    if(!map && !array) throw LOOKUP_X.get(info, it);
+    return (FItem) it;
+  }
+
+  /**
+   * Evaluates the {@code ?*} construct.
+   * @param qc query context
+   * @return all entries of all input values
+   * @throws QueryException query exception
+   */
+  private Value wildCard(final QueryContext qc) throws QueryException {
+    final ValueBuilder vb = new ValueBuilder();
+    for(final Item ctx : exprs.length == 1 ? ctxValue(qc) : qc.value(exprs[1])) {
+      if(ctx instanceof Map) {
+        for(final Value v : ((Map) ctx).values()) vb.add(v);
+      } else if(ctx instanceof Array) {
+        for(final Value val : ((Array) ctx).members()) vb.add(val);
       } else {
-        final Iter ir = qc.iter(exprs[0]);
-        for(Item it; (it = ir.next()) != null;) vb.add(f.invokeValue(qc, info, it));
+        throw LOOKUP_X.get(info, ctx);
       }
     }
-    return vb;
+    return vb.value();
+  }
+
+  /**
+   * Fast path for the case where the key is a single item.
+   * @param key key to look up
+   * @param qc query context
+   * @return resulting value
+   * @throws QueryException query exception
+   */
+  private Value lookup(final Item key, final QueryContext qc) throws QueryException {
+    final Iter iter = exprs.length == 1 ? ctxValue(qc).iter() : qc.iter(exprs[1]);
+
+    final Item fst = iter.next();
+    if(fst == null) return Empty.SEQ;
+
+    final Value fstVal = mapOrArray(fst).invokeValue(qc, info, key);
+    Item it = iter.next();
+    if(it == null) return fstVal;
+
+    final ValueBuilder vb = new ValueBuilder().add(fstVal);
+    do {
+      vb.add(mapOrArray(it).invokeValue(qc, info, key));
+    } while((it = iter.next()) != null);
+    return vb.value();
   }
 
   @Override
@@ -72,13 +165,25 @@
 
   @Override
   public Lookup copy(final QueryContext qc, final VarScope scp, final IntObjMap<Var> vs) {
-    return copyType(new Lookup(info, copyAll(qc, scp, vs, exprs)));
+    return copyType(new Lookup(info, sc, copyAll(qc, scp, vs, exprs)));
   }
 
   @Override
   public String toString() {
     final StringBuilder sb = new StringBuilder();
-    if(exprs.length > 1) sb.append(exprs[1]).append(' ');
-    return sb.append("? ").append(exprs[0]).toString();
+    if(exprs.length > 1) sb.append('(').append(exprs[1]).append(')');
+    final Expr key = exprs[0];
+
+    if(key == Str.WC) {
+      return sb.append("?*").toString();
+    } else if(key instanceof Str) {
+      final Str str = (Str) key;
+      if(XMLToken.isNCName(str.string())) return sb.append('?').append(str.toJava()).toString();
+    } else if(key instanceof Int) {
+      final long val = ((Int) key).itr();
+      if(val >= 0) return sb.append('?').append(val).toString();
+    }
+
+    return sb.append(" ? (").append(exprs[0]).append(')').toString();
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/ParseExpr.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/ParseExpr.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/ParseExpr.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/ParseExpr.java	2015-07-14 10:54:40.000000000 +0000
@@ -32,7 +32,7 @@
 
   /**
    * Constructor.
-   * @param info input info
+   * @param info input info (can be {@code null}
    */
   protected ParseExpr(final InputInfo info) {
     this.info = info;
@@ -51,7 +51,7 @@
     if(it == null || ir.size() == 1) return it;
     final Item n = ir.next();
     if(n != null) {
-      final ValueBuilder vb = new ValueBuilder(3).add(it).add(n);
+      final ValueBuilder vb = new ValueBuilder().add(it).add(n);
       if(ir.next() != null) vb.add(Str.get(DOTS));
       throw SEQFOUND_X.get(ii, vb.value());
     }
@@ -101,7 +101,7 @@
       if(it != null && !(it instanceof ANode)) {
         final Item n = ir.next();
         if(n != null) {
-          final ValueBuilder vb = new ValueBuilder(3).add(it).add(n);
+          final ValueBuilder vb = new ValueBuilder().add(it).add(n);
           if(ir.next() != null) vb.add(Str.get(DOTS));
           throw EBV_X.get(ii, vb.value());
         }
@@ -444,6 +444,22 @@
   }
 
   /**
+   * Checks if the evaluated expression yields a non-empty node or item.
+   * Returns the item or throws an exception.
+   * @param ex expression to be evaluated
+   * @param qc query context
+   * @return item
+   * @throws QueryException query exception
+   */
+  protected final Item toNodeOrAtomItem(final Expr ex, final QueryContext qc)
+      throws QueryException {
+
+    Item it = toItem(ex, qc);
+    if(!(it instanceof ANode)) it = it.atomItem(info);
+    return it;
+  }
+
+  /**
    * Checks if the evaluated expression yields a non-empty item.
    * Returns the item or throws an exception.
    * @param ex expression to be evaluated
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/path/Axis.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/path/Axis.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/path/Axis.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/path/Axis.java	2015-07-14 10:54:40.000000000 +0000
@@ -17,7 +17,7 @@
   /** Ancestor-or-self axis. */
   ANCORSELF("ancestor-or-self", false) {
     @Override
-    AxisIter iter(final ANode n) {
+    BasicNodeIter iter(final ANode n) {
       return n.ancestorOrSelf();
     }
   },
@@ -25,7 +25,7 @@
   /** Ancestor axis. */
   ANC("ancestor", false) {
     @Override
-    AxisIter iter(final ANode n) {
+    BasicNodeIter iter(final ANode n) {
       return n.ancestor();
     }
   },
@@ -33,7 +33,7 @@
   /** Attribute axis. */
   ATTR("attribute", true) {
     @Override
-    AxisIter iter(final ANode n) {
+    BasicNodeIter iter(final ANode n) {
       return n.attributes();
     }
   },
@@ -41,7 +41,7 @@
   /** Child Axis. */
   CHILD("child", true) {
     @Override
-    AxisIter iter(final ANode n) {
+    BasicNodeIter iter(final ANode n) {
       return n.children();
     }
   },
@@ -49,7 +49,7 @@
   /** Descendant-or-self axis. */
   DESCORSELF("descendant-or-self", true) {
     @Override
-    AxisIter iter(final ANode n) {
+    BasicNodeIter iter(final ANode n) {
       return n.descendantOrSelf();
     }
   },
@@ -57,7 +57,7 @@
   /** Descendant axis. */
   DESC("descendant", true) {
     @Override
-    AxisIter iter(final ANode n) {
+    BasicNodeIter iter(final ANode n) {
       return n.descendant();
     }
   },
@@ -65,7 +65,7 @@
   /** Following-Sibling axis. */
   FOLLSIBL("following-sibling", false) {
     @Override
-    AxisIter iter(final ANode n) {
+    BasicNodeIter iter(final ANode n) {
       return n.followingSibling();
     }
   },
@@ -73,7 +73,7 @@
   /** Following axis. */
   FOLL("following", false) {
     @Override
-    AxisIter iter(final ANode n) {
+    BasicNodeIter iter(final ANode n) {
       return n.following();
     }
   },
@@ -81,7 +81,7 @@
   /** Parent axis. */
   PARENT("parent", true) {
     @Override
-    AxisIter iter(final ANode n) {
+    BasicNodeIter iter(final ANode n) {
       return n.parentIter();
     }
   },
@@ -89,7 +89,7 @@
   /** Preceding-Sibling axis. */
   PRECSIBL("preceding-sibling", false) {
     @Override
-    AxisIter iter(final ANode n) {
+    BasicNodeIter iter(final ANode n) {
       return n.precedingSibling();
     }
   },
@@ -97,7 +97,7 @@
   /** Preceding axis. */
   PREC("preceding", false) {
     @Override
-    AxisIter iter(final ANode n) {
+    BasicNodeIter iter(final ANode n) {
       return n.preceding();
     }
   },
@@ -105,7 +105,7 @@
   /** Step axis. */
   SELF("self", true) {
     @Override
-    AxisIter iter(final ANode n) {
+    BasicNodeIter iter(final ANode n) {
       return n.self();
     }
   };
@@ -132,7 +132,7 @@
    * @param n input node
    * @return node iterator
    */
-  abstract AxisIter iter(final ANode n);
+  abstract BasicNodeIter iter(final ANode n);
 
   @Override
   public String toString() {
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/path/AxisPath.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/path/AxisPath.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/path/AxisPath.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/path/AxisPath.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,7 +1,11 @@
 package org.basex.query.expr.path;
 
+import org.basex.query.*;
 import org.basex.query.expr.*;
+import org.basex.query.iter.*;
 import org.basex.query.util.list.*;
+import org.basex.query.value.*;
+import org.basex.query.value.node.*;
 import org.basex.util.*;
 
 /**
@@ -11,6 +15,21 @@
  * @author Christian Gruen
  */
 public abstract class AxisPath extends Path {
+  /** Caching states. */
+  private enum Caching {
+    /** Caching is disabled. */ DISABLED,
+    /** Caching is possible. */ ENABLED,
+    /** Ready to cache.      */ READY,
+    /** Results are cached.  */ CACHED;
+  };
+  /** Current state. */
+  private Caching state;
+
+  /** Cached result. */
+  private Value cached;
+  /** Cached context value. */
+  private Value cvalue;
+
   /**
    * Constructor.
    * @param info input info
@@ -19,9 +38,61 @@
    */
   AxisPath(final InputInfo info, final Expr root, final Expr... steps) {
     super(info, root, steps);
+    // cache values if expression has no free variables, is deterministic and performs no updates
+    state = !hasFreeVars() && !has(Flag.NDT) && !has(Flag.UPD) && !has(Flag.HOF) ?
+      Caching.ENABLED : Caching.DISABLED;
+  }
+
+  @Override
+  public final Iter iter(final QueryContext qc) throws QueryException {
+    if(state == Caching.CACHED) {
+      // last result was cached
+      if(!sameContext(qc)) {
+        // disable caching if context has changed (expected to change frequently)
+        cached = null;
+        state = Caching.DISABLED;
+      }
+    } else if (state == Caching.READY) {
+      // values are ready to cache
+      if(sameContext(qc)) {
+        cached = nodeIter(qc).value();
+        state = Caching.CACHED;
+      } else {
+        // disable caching if context has changed (expected to change frequently)
+        state = Caching.DISABLED;
+      }
+    } else if(state == Caching.ENABLED) {
+      // caching is possible: remember context value
+      cvalue = qc.value instanceof DBNode ? ((DBNode) qc.value).copy() : qc.value;
+      state = Caching.READY;
+    }
+    // return new iterator or cached values
+    return cached == null ? nodeIter(qc) : cached.iter();
   }
 
   /**
+   * Checks if the specified context value is different to the cached one.
+   * @param qc query context
+   * @return result of check
+   */
+  private boolean sameContext(final QueryContext qc) {
+    final Value cv = qc.value;
+    // context value has not changed...
+    if(cv == cvalue && (cv == null || cv.sameAs(cvalue))) return true;
+    // otherwise, if path starts with root node, compare roots of cached and new context value
+    return root instanceof Root && cv instanceof ANode && cvalue instanceof ANode &&
+        ((ANode) cv).root().sameAs(((ANode) cv).root());
+  }
+
+  /**
+   * Returns a node iterator.
+   * @param qc query context
+   * @return iterator
+   * @throws QueryException query exception
+   */
+  protected abstract NodeIter nodeIter(final QueryContext qc) throws QueryException;
+
+  /**
    * Inverts a location path.
    * @param rt new root node
    * @param curr current location step
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/path/CachedPath.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/path/CachedPath.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/path/CachedPath.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/path/CachedPath.java	2015-07-14 10:54:40.000000000 +0000
@@ -5,6 +5,7 @@
 import org.basex.query.*;
 import org.basex.query.expr.*;
 import org.basex.query.iter.*;
+import org.basex.query.util.list.*;
 import org.basex.query.value.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.node.*;
@@ -19,9 +20,6 @@
  * @author Christian Gruen
  */
 final class CachedPath extends AxisPath {
-  /** Flag for result caching. */
-  private boolean cache;
-
   /**
    * Constructor.
    * @param info input info
@@ -30,16 +28,14 @@
    */
   CachedPath(final InputInfo info, final Expr root, final Expr... steps) {
     super(info, root, steps);
-    // analyze if result set can be cached: no root node, no variables...
-    cache = root != null && !hasFreeVars();
   }
 
   @Override
-  public Iter iter(final QueryContext qc) throws QueryException {
+  protected NodeIter nodeIter(final QueryContext qc) throws QueryException {
     final long cp = qc.pos, cs = qc.size;
     final Value cv = qc.value, r = root != null ? qc.value(root) : cv;
+    final ANodeList list = new ANodeList().check();
     try {
-      final NodeSeqBuilder nb = new NodeSeqBuilder().check();
       if(r != null) {
         final Iter ir = qc.iter(r);
         for(Item it; (it = ir.next()) != null;) {
@@ -47,40 +43,40 @@
           if(root != null && !(it instanceof ANode))
             throw PATHNODE_X_X_X.get(info, steps[0], it.type, it);
           qc.value = it;
-          iter(0, nb, qc);
+          iter(0, list, qc);
         }
       } else {
         qc.value = null;
-        iter(0, nb, qc);
+        iter(0, list, qc);
       }
-      return nb.sort();
     } finally {
       qc.value = cv;
       qc.size = cs;
       qc.pos = cp;
     }
+    return list.iter();
   }
 
   /**
    * Recursive step iterator.
-   * @param l current step
-   * @param nc node cache
+   * @param step current step
+   * @param list node cache
    * @param qc query context
    * @throws QueryException query exception
    */
-  private void iter(final int l, final NodeSeqBuilder nc, final QueryContext qc)
+  private void iter(final int step, final ANodeList list, final QueryContext qc)
       throws QueryException {
 
     // cast is safe (steps will always return a {@link NodeIter} instance)
-    final NodeIter ni = (NodeIter) qc.iter(steps[l]);
-    final boolean more = l + 1 != steps.length;
+    final NodeIter ni = (NodeIter) qc.iter(steps[step]);
+    final boolean more = step + 1 != steps.length;
     for(ANode node; (node = ni.next()) != null;) {
       if(more) {
         qc.value = node;
-        iter(l + 1, nc, qc);
+        iter(step + 1, list, qc);
       } else {
         qc.checkStop();
-        nc.add(node);
+        list.add(node);
       }
     }
   }
@@ -88,8 +84,6 @@
   @Override
   public AxisPath copy(final QueryContext qc, final VarScope scp, final IntObjMap<Var> vs) {
     final Expr rt = root == null ? null : root.copy(qc, scp, vs);
-    final CachedPath ap = copyType(new CachedPath(info, rt, Arr.copyAll(qc, scp, vs, steps)));
-    ap.cache = cache;
-    return ap;
+    return copyType(new CachedPath(info, rt, Arr.copyAll(qc, scp, vs, steps)));
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/path/CachedStep.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/path/CachedStep.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/path/CachedStep.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/path/CachedStep.java	2015-07-14 10:54:40.000000000 +0000
@@ -3,6 +3,7 @@
 import org.basex.query.*;
 import org.basex.query.expr.*;
 import org.basex.query.iter.*;
+import org.basex.query.util.list.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.node.*;
 import org.basex.query.var.*;
@@ -28,35 +29,35 @@
   }
 
   @Override
-  public NodeSeqBuilder iter(final QueryContext qc) throws QueryException {
+  public NodeIter iter(final QueryContext qc) throws QueryException {
     // evaluate step
-    final AxisIter ai = axis.iter(checkNode(qc));
-    final NodeSeqBuilder nc = new NodeSeqBuilder();
-    for(ANode n; (n = ai.next()) != null;) {
-      if(test.eq(n)) nc.add(n.finish());
+    final BasicNodeIter iter = axis.iter(checkNode(qc));
+    final ANodeList list = new ANodeList();
+    for(ANode n; (n = iter.next()) != null;) {
+      if(test.eq(n)) list.add(n.finish());
     }
 
     // evaluate predicates
     final boolean scoring = qc.scoring;
     for(final Expr pred : preds) {
-      final long nl = nc.size();
+      final long nl = list.size();
       qc.size = nl;
       qc.pos = 1;
       int c = 0;
       for(int n = 0; n < nl; ++n) {
-        final ANode node = nc.get(n);
+        final ANode node = list.get(n);
         qc.value = node;
         final Item tst = pred.test(qc, info);
         if(tst != null) {
           // assign score value
           if(scoring) node.score(tst.score());
-          nc.nodes[c++] = node;
+          list.set(c++, node);
         }
         qc.pos++;
       }
-      nc.size(c);
+      list.size(c);
     }
-    return nc;
+    return list.iter();
   }
 
   @Override
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/path/DocTest.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/path/DocTest.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/path/DocTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/path/DocTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -11,12 +11,12 @@
  * @author Christian Gruen
  */
 public final class DocTest extends Test {
-  /** Optional child test. */
+  /** Child test. */
   private final Test test;
 
   /**
    * Constructor.
-   * @param test child test (may be {@code null})
+   * @param test child test
    */
   public DocTest(final Test test) {
     this.test = test;
@@ -31,8 +31,14 @@
   @Override
   public boolean eq(final ANode node) {
     if(node.type != NodeType.DOC) return false;
-    final AxisMoreIter ai = node.children();
-    return ai.more() && test.eq(ai.next()) && !ai.more();
+    final BasicNodeIter iter = node.children();
+    boolean found = false;
+    for(ANode n; (n = iter.next()) != null;) {
+      if(n.type == NodeType.COM || n.type == NodeType.PI) continue;
+      if(found || !test.eq(n)) return false;
+      found = true;
+    }
+    return true;
   }
 
   @Override
@@ -55,8 +61,6 @@
 
   @Override
   public String toString() {
-    final StringBuilder sb = new StringBuilder().append(type).append('(');
-    if(test != null) sb.append(test);
-    return sb.append(')').toString();
+    return test.toString();
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/path/InvDocTest.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/path/InvDocTest.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/path/InvDocTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/path/InvDocTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -46,13 +46,13 @@
     // adopt nodes from existing sequence
     if(rt instanceof DBNodeSeq) {
       final DBNodeSeq seq = (DBNodeSeq) rt;
-      return seq.all ? Test.DOC : new InvDocTest(new IntList(seq.pres), data);
+      return seq.all() ? Test.DOC : new InvDocTest(new IntList(seq.pres()), data);
     }
 
     // loop through all documents and add pre values of documents
     // not more than 2^31 documents supported
     final IntList il = new IntList((int) rt.size());
-    for(final Item it : rt) il.add(((DBNode) it).pre);
+    for(final Item it : rt) il.add(((DBNode) it).pre());
     return new InvDocTest(il, data);
   }
 
@@ -62,7 +62,7 @@
     if(!(node instanceof DBNode)) return false;
     // ensure that the pre value is contained in the target documents
     final DBNode db = (DBNode) node;
-    return data == db.data && pres.contains(db.pre);
+    return data == db.data() && pres.contains(db.pre());
   }
 
   @Override
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/path/IterLastStep.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/path/IterLastStep.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/path/IterLastStep.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/path/IterLastStep.java	2015-07-14 10:54:40.000000000 +0000
@@ -37,7 +37,7 @@
         stop = true;
 
         // return last items
-        final AxisIter iter = axis.iter(checkNode(qc));
+        final BasicNodeIter iter = axis.iter(checkNode(qc));
         ANode litem = null;
         final Test tst = test;
         for(ANode item; (item = iter.next()) != null;) {
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/path/IterPath.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/path/IterPath.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/path/IterPath.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/path/IterPath.java	2015-07-14 10:54:40.000000000 +0000
@@ -32,7 +32,7 @@
   }
 
   @Override
-  public NodeIter iter(final QueryContext qc) {
+  protected NodeIter nodeIter(final QueryContext qc) {
     return new NodeIter() {
       final boolean r = root != null;
       final int sz = steps.length + (r ? 1 : 0);
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/path/IterPosStep.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/path/IterPosStep.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/path/IterPosStep.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/path/IterPosStep.java	2015-07-14 10:54:40.000000000 +0000
@@ -35,13 +35,13 @@
       final Pos[] posExpr = new Pos[preds.length];
       final long[] cPos = new long[preds.length];
       boolean skip;
-      AxisIter ai;
+      BasicNodeIter iter;
 
       @Override
       public ANode next() throws QueryException {
         if(skip) return null;
-        if(ai == null) {
-          ai = axis.iter(checkNode(qc));
+        if(iter == null) {
+          iter = axis.iter(checkNode(qc));
           final int pl = preds.length;
           for(int p = 0; p < pl; p++) {
             final Expr pred = preds[p];
@@ -49,7 +49,9 @@
               posExpr[p] = (Pos) pred;
             } else if(num(pred)) {
               // pre-evaluate numeric position
-              final double dbl = toDouble(pred, qc);
+              final Item it = pred.atomItem(qc, info);
+              if(it == null) return null;
+              final double dbl = toDouble(it);
               final long lng = (long) dbl;
               if(dbl != lng) return null;
               final Expr e = Pos.get(lng, info);
@@ -59,7 +61,7 @@
           }
         }
 
-        for(ANode node; (node = ai.next()) != null;) {
+        for(ANode node; (node = iter.next()) != null;) {
           qc.checkStop();
           if(test.eq(node) && preds(node)) return node.finish();
         }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/path/IterStep.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/path/IterStep.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/path/IterStep.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/path/IterStep.java	2015-07-14 10:54:40.000000000 +0000
@@ -30,12 +30,12 @@
   @Override
   public NodeIter iter(final QueryContext qc) {
     return new NodeIter() {
-      AxisIter ai;
+      BasicNodeIter iter;
 
       @Override
       public ANode next() throws QueryException {
-        if(ai == null) ai = axis.iter(checkNode(qc));
-        for(ANode node; (node = ai.next()) != null;) {
+        if(iter == null) iter = axis.iter(checkNode(qc));
+        for(ANode node; (node = iter.next()) != null;) {
           qc.checkStop();
           if(test.eq(node) && preds(node, qc)) return node.finish();
         }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/path/MixedPath.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/path/MixedPath.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/path/MixedPath.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/path/MixedPath.java	2015-07-14 10:54:40.000000000 +0000
@@ -5,6 +5,7 @@
 import org.basex.query.*;
 import org.basex.query.expr.*;
 import org.basex.query.iter.*;
+import org.basex.query.util.list.*;
 import org.basex.query.value.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.node.*;
@@ -36,9 +37,24 @@
 
   @Override
   public Iter iter(final QueryContext qc) throws QueryException {
-    // creates an iterator from the root value
-    final Value v = root != null ? qc.value(root) : ctxValue(qc);
-    Iter res = v.iter();
+    Iter iter;
+    long sz;
+    if(root != null) {
+      final Iter rt = qc.iter(root);
+      final long s = rt.size();
+      if(s >= 0) {
+        iter = rt;
+        sz = s;
+      } else {
+        final Value val = rt.value();
+        iter = val.iter();
+        sz = val.size();
+      }
+    } else {
+      final Value rt = ctxValue(qc);
+      iter = rt.iter();
+      sz = rt.size();
+    }
 
     final Value cv = qc.value;
     final long cs = qc.size;
@@ -48,15 +64,15 @@
       final int sl = steps.length;
       for(int s = 0; s < sl; s++) {
         final Expr step = steps[s];
-        final ValueBuilder vb = new ValueBuilder();
+        final ItemList cache = new ItemList();
 
         // map operator: don't remove duplicates and check for nodes
-        qc.size = res.size();
+        qc.size = sz;
         qc.pos = 1;
 
         // loop through all input items
-        int nodes = 0;
-        for(Item it; (it = res.next()) != null;) {
+        long nodes = 0;
+        for(Item it; (it = iter.next()) != null;) {
           if(!(it instanceof ANode)) throw PATHNODE_X_X_X.get(info, step, it.type, it);
           qc.value = it;
 
@@ -64,32 +80,32 @@
           final Iter ir = qc.iter(step);
           for(Item i; (i = ir.next()) != null;) {
             if(i instanceof ANode) nodes++;
-            vb.add(i);
+            cache.add(i);
           }
           qc.pos++;
         }
 
-        final long vs = vb.size();
+        final long vs = cache.size();
         if(nodes < vs) {
           // check if both nodes and atomic values occur in last result
           if(nodes > 0) throw EVALNODESVALS.get(info);
           // check if input for next axis step consists items other than nodes
           if(s + 1 < sl) {
-            final Item it = vb.get(0);
+            final Item it = cache.get(0);
             throw PATHNODE_X_X_X.get(info, steps[s + 1], it.type, it);
           }
         }
 
         if(nodes == vs) {
           // remove potential duplicates from node sets
-          final NodeSeqBuilder nc = new NodeSeqBuilder().check();
-          for(Item it; (it = vb.next()) != null;) nc.add((ANode) it);
-          res = nc.value().cache();
+          final ANodeList list = new ANodeList().check();
+          for(final Item nd : cache) list.add((ANode) nd);
+          iter = list.iter();
         } else {
-          res = vb;
+          iter = cache.iter();
         }
       }
-      return res;
+      return iter;
     } finally {
       qc.value = cv;
       qc.size = cs;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/path/NameTest.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/path/NameTest.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/path/NameTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/path/NameTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -51,7 +51,7 @@
     if(data == null) return true;
 
     // skip optimizations if more than one namespace is defined in the database
-    final byte[] dataNS = data.nspaces.globalNS();
+    final byte[] dataNS = data.nspaces.globalUri();
     if(dataNS == null) return true;
 
     // check if test may yield results
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/path/NodeTest.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/path/NodeTest.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/path/NodeTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/path/NodeTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -14,15 +14,13 @@
 public final class NodeTest extends Test {
   /** Extended type. */
   private final Type ext;
-  /** Strip flag (only relevant if specified type is {@code xs:untyped}). */
-  private final boolean strip;
 
   /**
    * Convenience constructor for element tests.
    * @param nm node name
    */
   public NodeTest(final QNm nm) {
-    this(NodeType.ELM, nm, null, false);
+    this(NodeType.ELM, nm, null);
   }
 
   /**
@@ -31,7 +29,7 @@
    * @param nm optional node name
    */
   public NodeTest(final NodeType nt, final QNm nm) {
-    this(nt, nm, null, false);
+    this(nt, nm, null);
   }
 
   /**
@@ -39,32 +37,28 @@
    * @param type node type
    * @param name optional node name
    * @param ext extended node type
-   * @param strip strip flag; only relevant if specified type is {@code xs:untyped}
    */
-  public NodeTest(final NodeType type, final QNm name, final Type ext, final boolean strip) {
+  public NodeTest(final NodeType type, final QNm name, final Type ext) {
     this.type = type;
     this.name = name;
     this.ext = ext;
-    this.strip = strip;
   }
 
   @Override
   public Test copy() {
-    return new NodeTest(type, name, ext, strip);
+    return new NodeTest(type, name, ext);
   }
 
   @Override
   public boolean eq(final ANode node) {
     return node.type == type &&
       (name == null || node.qname(tmpq).eq(name)) &&
-      (ext == null || ext == AtomType.ATY ||
-      (node instanceof DBNode || strip) && ext == AtomType.UTY ||
-      type == NodeType.ATT && (ext == AtomType.AST ||
-      ext == AtomType.AAT || ext == AtomType.ATM));
+      (ext == null || ext == AtomType.ATY || ext == AtomType.UTY ||
+      type == NodeType.ATT && (ext == AtomType.AST || ext == AtomType.AAT || ext == AtomType.ATM));
   }
 
   @Override
-  public Test intersect(final Test other) {
+  public NodeTest intersect(final Test other) {
     if(other instanceof NodeTest) {
       final NodeTest o = (NodeTest) other;
       if(type != null && o.type != null && type != o.type) return null;
@@ -73,7 +67,7 @@
       final QNm n = name != null ? name : o.name;
       final boolean both = ext != null && o.ext != null;
       final Type e = ext == null ? o.ext : o.ext == null ? ext : ext.intersect(o.ext);
-      return both && e == null ? null : new NodeTest(nt, n, e, strip || o.strip);
+      return both && e == null ? null : new NodeTest(nt, n, e);
     }
     if(other instanceof KindTest) {
       return type.instanceOf(other.type) ? this : null;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/path/Path.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/path/Path.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/path/Path.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/path/Path.java	2015-07-14 10:54:40.000000000 +0000
@@ -74,26 +74,26 @@
       rt = path.root;
     }
     // remove redundant context reference
-    if(rt instanceof Context) rt = null;
+    if(rt instanceof ContextValue) rt = null;
 
     // add steps of input array
     for(final Expr expr : steps) {
       Expr step = expr;
-      if(step instanceof Context) {
+      if(step instanceof ContextValue) {
         // remove redundant context references
         if(sl > 1) continue;
         // single step: rewrite to axis step (required to sort results of path)
-        step = Step.get(((Context) step).info, SELF, Test.NOD);
+        step = Step.get(((ContextValue) step).info, SELF, Test.NOD);
       } else if(step instanceof Filter) {
         // rewrite filter to axis step
         final Filter f = (Filter) step;
-        if(f.root instanceof Context) {
+        if(f.root instanceof ContextValue) {
           step = Step.get(f.info, SELF, Test.NOD, f.preds);
         }
       } else if(step instanceof Path) {
         // rewrite path to axis steps
         final Path p = (Path) step;
-        if(p.root != null && !(p.root instanceof Context)) stps.add(p.root);
+        if(p.root != null && !(p.root instanceof ContextValue)) stps.add(p.root);
         final int pl = p.steps.length - 1;
         for(int i = 0; i < pl; i++) stps.add(p.steps[i]);
         step = p.steps[pl];
@@ -123,7 +123,7 @@
   public final Expr compile(final QueryContext qc, final VarScope scp) throws QueryException {
     if(root != null) root = root.compile(qc, scp);
     // no steps
-    if(steps.length == 0) return root == null ? new Context(info) : root;
+    if(steps.length == 0) return root == null ? new ContextValue(info) : root;
 
     final Value init = qc.value, cv = initial(qc);
     qc.value = cv;
@@ -231,9 +231,12 @@
 
   @Override
   public final boolean has(final Flag flag) {
-    // first step or root expression will be used as context
+    // context dependency. no root exists, or if it depends on context. Example: text(); ./abc
     if(flag == Flag.CTX) return root == null || root.has(flag);
-    for(final Expr s : steps) if(s.has(flag)) return true;
+    // positional test. may only occur in root node, not in first step. Example: position()/a
+    if(flag != Flag.POS) {
+      for(final Expr step : steps) if(step.has(flag)) return true;
+    }
     return root != null && root.has(flag);
   }
 
@@ -377,9 +380,9 @@
     // current context value
     final Value v = qc != null ? qc.value : null;
     // no root or context expression: return context
-    if(root == null || root instanceof Context) return v;
+    if(root == null || root instanceof ContextValue) return v;
     // root reference
-    if(root instanceof Root) return v instanceof Item ? Root.root(v) : v;
+    if(root instanceof Root) return v instanceof ANode ? ((ANode) v).root() : v;
     // root is value: return root
     if(root.isValue()) return (Value) root;
     // data reference
@@ -540,7 +543,7 @@
   private Expr children(final QueryContext qc, final Value rt) {
     // skip if index does not exist or is out-dated, or if several namespaces occur in the input
     final Data data = rt.data();
-    if(data == null || !data.meta.uptodate || data.nspaces.globalNS() == null) return this;
+    if(data == null || !data.meta.uptodate || data.nspaces.globalUri() == null) return this;
 
     Path path = this;
     final int sl = steps.length;
@@ -551,7 +554,7 @@
 
       // ignore axes other than descendant, or numeric predicates
       final Step curr = axisStep(s);
-      if(curr == null || curr.axis != DESC || curr.has(Flag.FCS)) continue;
+      if(curr == null || curr.axis != DESC || curr.has(Flag.POS)) continue;
 
       // check if child steps can be retrieved for current step
       ArrayList<PathNode> nodes = pathNodes(data, s);
@@ -637,7 +640,7 @@
       // only accept descendant steps without positional predicates
       // Example for position predicate: child:x[1] != parent::x[1]
       final Step step = axisStep(s);
-      if(step == null || !step.axis.down || step.has(Flag.FCS)) break;
+      if(step == null || !step.axis.down || step.has(Flag.POS)) break;
 
       // check if path is iterable (i.e., will be duplicate-free)
       final boolean iter = pathNodes(data, s) != null;
@@ -784,7 +787,7 @@
             continue;
           }
           // //(X, Y)[text()] -> (/descendant::X | /descendant::Y)[text()]
-          if(next instanceof Filter && !next.has(Flag.FCS)) {
+          if(next instanceof Filter && !next.has(Flag.POS)) {
             final Filter f = (Filter) next;
             e = mergeList(f.root);
             if(e != null) {
@@ -843,8 +846,8 @@
    */
   private static boolean simpleChild(final Expr expr) {
     if(expr instanceof Step) {
-      final Step n = (Step) expr;
-      if(n.axis == CHILD && !n.has(Flag.FCS)) return true;
+      final Step step = (Step) expr;
+      if(step.axis == CHILD && !step.has(Flag.POS)) return true;
     }
     return false;
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/path/Step.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/path/Step.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/path/Step.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/path/Step.java	2015-07-14 10:54:40.000000000 +0000
@@ -53,7 +53,7 @@
     for(final Expr pred : preds) {
       if(pred instanceof Pos || num(pred)) {
         pos = true;
-      } else if(pred.seqType().mayBeNumber() || pred.has(Flag.FCS)) {
+      } else if(pred.seqType().mayBeNumber() || pred.has(Flag.POS)) {
         // positional checks may be nested or non-deterministic: choose full evaluation
         return new CachedStep(info, axis, test, preds);
       }
@@ -126,7 +126,7 @@
    */
   final ArrayList<PathNode> nodes(final ArrayList<PathNode> nodes, final Data data) {
     // skip steps with predicates or different namespaces
-    if(preds.length != 0 || data.nspaces.globalNS() == null) return null;
+    if(preds.length != 0 || data.nspaces.globalUri() == null) return null;
 
     // check restrictions on node type
     int kind = -1, name = 0;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/Pos.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/Pos.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/Pos.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/Pos.java	2015-07-14 10:54:40.000000000 +0000
@@ -143,7 +143,7 @@
 
   @Override
   public boolean has(final Flag flag) {
-    return flag == Flag.FCS;
+    return flag == Flag.POS;
   }
 
   @Override
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/Pragma.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/Pragma.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/Pragma.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/Pragma.java	2015-07-14 10:54:40.000000000 +0000
@@ -3,6 +3,7 @@
 import static org.basex.query.QueryText.*;
 
 import org.basex.query.*;
+import org.basex.query.expr.Expr.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.node.*;
 import org.basex.util.*;
@@ -21,12 +22,12 @@
 
   /**
    * Constructor.
-   * @param n name of pragma
-   * @param v optional value
+   * @param name name of pragma
+   * @param value optional value
    */
-  Pragma(final QNm n, final byte[] v) {
-    name = n;
-    value = v;
+  Pragma(final QNm name, final byte[] value) {
+    this.name = name;
+    this.value = value;
   }
 
   @Override
@@ -48,6 +49,14 @@
    */
   abstract void finish(final QueryContext qc);
 
+  /**
+   * Indicates if an expression has the specified compiler property.
+   * @param flag flag to be checked
+   * @return result of check
+   * @see Expr#has
+   */
+  public abstract boolean has(final Flag flag);
+
   @Override
   public final String toString() {
     final TokenBuilder tb = new TokenBuilder(PRAGMA + ' ' + name + ' ');
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/Preds.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/Preds.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/Preds.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/Preds.java	2015-07-14 10:54:40.000000000 +0000
@@ -89,7 +89,7 @@
           }
         }
       } else if(pred instanceof And) {
-        if(!pred.has(Flag.FCS)) {
+        if(!pred.has(Flag.POS)) {
           // replace AND expression with predicates (don't swap position tests)
           qc.compInfo(OPTPRED, pred);
           final Expr[] and = ((Arr) pred).exprs;
@@ -205,7 +205,7 @@
 
     final Expr pred = preds[0];
     // a[.] -> a
-    if(pred instanceof Context) return root;
+    if(pred instanceof ContextValue) return root;
 
     if(!pred.seqType().mayBeNumber()) {
       // a[b] -> a/b
@@ -218,7 +218,7 @@
         if(!expr2.has(Flag.CTX)) {
           Expr path = null;
           // a[. = 'x'] -> a = 'x'
-          if(expr1 instanceof Context) path = root;
+          if(expr1 instanceof ContextValue) path = root;
           // a[text() = 'x'] -> a/text() = 'x'
           if(expr1 instanceof Path) path = Path.get(info, root, expr1).optimize(qc, scp);
           if(path != null) return new CmpG(path, expr2, cmp.op, cmp.coll, cmp.sc, cmp.info);
@@ -233,7 +233,7 @@
           final Expr expr = cmp.expr;
           Expr path = null;
           // a[. contains text 'x'] -> a contains text 'x'
-          if(expr instanceof Context) path = root;
+          if(expr instanceof ContextValue) path = root;
           // [text() contains text 'x'] -> a/text() contains text 'x'
           if(expr instanceof Path) path = Path.get(info, root, expr).optimize(qc, scp);
           if(path != null) return new FTContains(path, ftexpr, cmp.info);
@@ -244,7 +244,7 @@
   }
 
   /**
-   * Checks if the specified expression returns a deterministic numeric value.
+   * Checks if the specified expression returns an empty sequence or a deterministic numeric value.
    * @param expr expression
    * @return result of check
    */
@@ -256,7 +256,7 @@
   @Override
   public boolean has(final Flag flag) {
     for(final Expr pred : preds) {
-      if(flag == Flag.FCS && pred.seqType().mayBeNumber() || pred.has(flag)) return true;
+      if(flag == Flag.POS && pred.seqType().mayBeNumber() || pred.has(flag)) return true;
     }
     return false;
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/RangeAccess.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/RangeAccess.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/RangeAccess.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/RangeAccess.java	2015-07-14 10:54:40.000000000 +0000
@@ -37,10 +37,10 @@
   }
 
   @Override
-  public AxisIter iter(final QueryContext qc) {
+  public BasicNodeIter iter(final QueryContext qc) {
     final byte kind = index.type() == IndexType.TEXT ? Data.TEXT : Data.ATTR;
 
-    return new AxisIter() {
+    return new BasicNodeIter() {
       final IndexIterator it = ictx.data.iter(index);
       @Override
       public ANode next() {
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/Root.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/Root.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/Root.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/Root.java	2015-07-14 10:54:40.000000000 +0000
@@ -6,7 +6,7 @@
 import org.basex.query.*;
 import org.basex.query.iter.*;
 import org.basex.query.util.*;
-import org.basex.query.value.*;
+import org.basex.query.util.list.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.node.*;
 import org.basex.query.value.type.*;
@@ -36,15 +36,15 @@
   }
 
   @Override
-  public Iter iter(final QueryContext qc) throws QueryException {
+  public BasicNodeIter iter(final QueryContext qc) throws QueryException {
     final Iter iter = ctxValue(qc).iter();
-    final NodeSeqBuilder nc = new NodeSeqBuilder().check();
-    for(Item i; (i = iter.next()) != null;) {
-      final ANode n = root(i);
+    final ANodeList list = new ANodeList().check();
+    for(Item it; (it = iter.next()) != null;) {
+      final ANode n = it instanceof ANode ? ((ANode) it).root() : null;
       if(n == null || n.type != NodeType.DOC) throw CTXNODE.get(info);
-      nc.add(n);
+      list.add(n);
     }
-    return nc;
+    return list.iter();
   }
 
   @Override
@@ -52,21 +52,6 @@
     return new Root(info);
   }
 
-  /**
-   * Returns the root node of the specified item.
-   * @param v input node
-   * @return root node
-   */
-  public static ANode root(final Value v) {
-    if(!(v instanceof ANode)) return null;
-    ANode n = (ANode) v;
-    while(true) {
-      final ANode p = n.parent();
-      if(p == null) return n;
-      n = p;
-    }
-  }
-
   @Override
   public boolean has(final Flag flag) {
     return flag == Flag.CTX;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/Set.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/Set.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/Set.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/Set.java	2015-07-14 10:54:40.000000000 +0000
@@ -6,6 +6,7 @@
 
 import org.basex.query.*;
 import org.basex.query.iter.*;
+import org.basex.query.util.list.*;
 import org.basex.query.value.node.*;
 import org.basex.query.value.type.*;
 import org.basex.query.var.*;
@@ -55,16 +56,16 @@
     final int el = exprs.length;
     final Iter[] iter = new Iter[el];
     for(int e = 0; e < el; e++) iter[e] = qc.iter(exprs[e]);
-    return iterable ? iter(iter) : eval(iter).sort();
+    return iterable ? iter(iter) : eval(iter).iter();
   }
 
   /**
    * Evaluates the specified iterators.
    * @param iter iterators
-   * @return resulting iterator
+   * @return resulting node list
    * @throws QueryException query exception
    */
-  protected abstract NodeSeqBuilder eval(final Iter[] iter) throws QueryException;
+  protected abstract ANodeList eval(final Iter[] iter) throws QueryException;
 
   /**
    * Evaluates the specified iterators in an iterative manner.
@@ -94,10 +95,10 @@
 
     /**
      * Constructor.
-     * @param ir iterator
+     * @param iter iterator
      */
-    SetIter(final Iter[] ir) {
-      iter = ir;
+    SetIter(final Iter[] iter) {
+      this.iter = iter;
     }
 
     @Override
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/SimpleMap.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/SimpleMap.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/SimpleMap.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/SimpleMap.java	2015-07-14 10:54:40.000000000 +0000
@@ -33,7 +33,7 @@
    */
   public static SimpleMap get(final InputInfo info, final Expr... exprs) {
     for(final Expr expr : exprs) {
-      if(expr.has(Flag.FCS)) return new CachedMap(info, exprs);
+      if(expr.has(Flag.POS)) return new CachedMap(info, exprs);
     }
     return new IterMap(info, exprs);
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/StringRangeAccess.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/StringRangeAccess.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/StringRangeAccess.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/StringRangeAccess.java	2015-07-14 10:54:40.000000000 +0000
@@ -36,14 +36,14 @@
   }
 
   @Override
-  public AxisIter iter(final QueryContext qc) {
+  public BasicNodeIter iter(final QueryContext qc) {
     final byte kind = index.text ? Data.TEXT : Data.ATTR;
     final Data data = ictx.data;
     final int ml = data.meta.maxlen;
     final IndexIterator ii = index.min.length <= ml && index.max.length <= ml &&
         (index.text ? data.meta.textindex : data.meta.attrindex) ? data.iter(index) : scan();
 
-    return new AxisIter() {
+    return new BasicNodeIter() {
       @Override
       public ANode next() {
         return ii.more() ? new DBNode(data, ii.pre(), kind) : null;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/Treat.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/Treat.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/Treat.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/Treat.java	2015-07-14 10:54:40.000000000 +0000
@@ -59,7 +59,7 @@
     if(seqType.zeroOrOne()) {
       final Item n = iter.next();
       if(n != null) {
-        final ValueBuilder vb = new ValueBuilder(3).add(it).add(n);
+        final ValueBuilder vb = new ValueBuilder().add(it).add(n);
         if(iter.next() != null) vb.add(Str.get(DOTS));
         throw NOTREAT_X_X_X.get(info, expr.seqType(), seqType, vb.value());
       }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/TypeCheck.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/TypeCheck.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/TypeCheck.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/TypeCheck.java	2015-07-14 10:54:40.000000000 +0000
@@ -4,6 +4,7 @@
 
 import org.basex.query.*;
 import org.basex.query.iter.*;
+import org.basex.query.util.list.*;
 import org.basex.query.value.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.node.*;
@@ -72,7 +73,7 @@
     // check at each call
     if(argType.type.instanceOf(seqType.type) && !expr.has(Flag.NDT) && !expr.has(Flag.UPD)) {
       final Occ occ = argType.occ.intersect(seqType.occ);
-      if(occ == null) throw INVCAST_X_X.get(info, argType, seqType);
+      if(occ == null) throw INVPROMOTE_X_X.get(info, argType, seqType);
     }
 
     final Expr opt = expr.typeCheck(this, qc, scp);
@@ -87,7 +88,7 @@
 
     return new Iter() {
       /** Item cache. */
-      final ValueBuilder vb = new ValueBuilder();
+      final ItemList cache = new ItemList();
       /** Item cache index. */
       int c;
       /** Result index. */
@@ -96,21 +97,21 @@
       @Override
       public Item next() throws QueryException {
         final SeqType st = seqType;
-        while(c == vb.size()) {
+        while(c == cache.size()) {
           qc.checkStop();
-          vb.size(0);
+          cache.size(0);
           c = 0;
 
           final Item it = iter.next();
           if(it == null || st.instance(it, true)) {
-            vb.add(it);
+            cache.add(it);
           } else {
-            st.promote(qc, sc, info, it, false, vb);
+            st.promote(qc, sc, info, it, false, cache);
           }
         }
 
-        final Item it = vb.get(c);
-        vb.set(c++, null);
+        final Item it = cache.get(c);
+        cache.set(c++, null);
 
         if(it == null && i < st.occ.min || i > st.occ.max)
           throw INVPROMOTE_X_X.get(info, expr.seqType(), st);
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/Union.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/Union.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/Union.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/Union.java	2015-07-14 10:54:40.000000000 +0000
@@ -58,12 +58,12 @@
   }
 
   @Override
-  protected NodeSeqBuilder eval(final Iter[] iter) throws QueryException {
-    final NodeSeqBuilder nc = new NodeSeqBuilder().check();
+  protected ANodeList eval(final Iter[] iter) throws QueryException {
+    final ANodeList list = new ANodeList().check();
     for(final Iter ir : iter) {
-      for(Item it; (it = ir.next()) != null;) nc.add(toNode(it));
+      for(Item it; (it = ir.next()) != null;) list.add(toNode(it));
     }
-    return nc;
+    return list;
   }
 
   @Override
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/ValueAccess.java basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/ValueAccess.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/expr/ValueAccess.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/expr/ValueAccess.java	2015-07-14 10:54:40.000000000 +0000
@@ -50,13 +50,13 @@
   }
 
   @Override
-  public NodeIter iter(final QueryContext qc) throws QueryException {
-    final ArrayList<NodeIter> iter = new ArrayList<>();
+  public BasicNodeIter iter(final QueryContext qc) throws QueryException {
+    final ArrayList<BasicNodeIter> iter = new ArrayList<>();
     final Iter ir = qc.iter(expr);
     for(Item it; (it = ir.next()) != null;) iter.add(index(it.string(info)));
     final int is = iter.size();
-    return is == 0 ? AxisMoreIter.EMPTY : is == 1 ? iter.get(0) :
-      new Union(info, expr).eval(iter.toArray(new NodeIter[is]));
+    return is == 0 ? BasicNodeIter.EMPTY : is == 1 ? iter.get(0) :
+      new Union(info, expr).eval(iter.toArray(new NodeIter[is])).iter();
   }
 
   /**
@@ -64,12 +64,12 @@
    * @param term term to be found
    * @return iterator
    */
-  private AxisIter index(final byte[] term) {
+  private BasicNodeIter index(final byte[] term) {
     // special case: empty text node
     // - no element name: return 0 results (empty text nodes are non-existent)
     // - otherwise, return scan-based element iterator
     final int tl = term.length;
-    if(tl == 0 && text) return test == null ? AxisMoreIter.EMPTY : scanEmpty();
+    if(tl == 0 && text) return test == null ? BasicNodeIter.EMPTY : scanEmpty();
 
     // use index traversal if index exists and if term is not too long.
     // otherwise, scan data sequentially
@@ -79,14 +79,14 @@
 
     final int kind = text ? Data.TEXT : Data.ATTR;
     final DBNode tmp = new DBNode(data, 0, test == null ? kind : Data.ELEM);
-    return new AxisIter() {
+    return new BasicNodeIter() {
       @Override
       public ANode next() {
         while(ii.more()) {
           if(test == null) {
-            tmp.pre = ii.pre();
+            tmp.pre(ii.pre());
           } else {
-            tmp.pre = data.parent(ii.pre(), kind);
+            tmp.pre(data.parent(ii.pre(), kind));
             if(!test.eq(tmp)) continue;
           }
           return tmp.finish();
@@ -132,8 +132,8 @@
    * b) having no descendants.
    * @return node iterator
    */
-  private AxisIter scanEmpty() {
-    return new AxisIter() {
+  private BasicNodeIter scanEmpty() {
+    return new BasicNodeIter() {
       final Data data = ictx.data;
       final DBNode tmp = new DBNode(data, 0, Data.ELEM);
       final int sz = data.meta.size;
@@ -143,7 +143,7 @@
       public DBNode next() {
         while(++pre < sz) {
           if(data.kind(pre) == Data.ELEM && data.size(pre, Data.ELEM) == 1) {
-            tmp.pre = pre;
+            tmp.pre(pre);
             if(test == null || test.eq(tmp)) return tmp.finish();
           }
         }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/admin/AdminDeleteLogs.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/admin/AdminDeleteLogs.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/admin/AdminDeleteLogs.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/admin/AdminDeleteLogs.java	2015-07-14 10:54:40.000000000 +0000
@@ -23,11 +23,11 @@
 
     final String date = Token.string(toToken(exprs[0], qc));
     final String cdate = Log.name(new Date());
-    if(date.equals(cdate)) throw BXCA_TODAY.get(info, date + IO.LOGSUFFIX);
+    if(date.equals(cdate)) throw BXAD_TODAY.get(info, date + IO.LOGSUFFIX);
 
     final IOFile file = new IOFile(qc.context.log.dir(), date + IO.LOGSUFFIX);
     if(!file.exists()) throw WHICHRES_X.get(info, file);
-    if(!file.delete()) throw BXCA_DELETE_X.get(info, date + IO.LOGSUFFIX);
+    if(!file.delete()) throw BXAD_DELETE_X.get(info, date + IO.LOGSUFFIX);
     return null;
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/admin/AdminLogs.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/admin/AdminLogs.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/admin/AdminLogs.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/admin/AdminLogs.java	2015-07-14 10:54:40.000000000 +0000
@@ -11,6 +11,7 @@
 import org.basex.io.in.*;
 import org.basex.query.*;
 import org.basex.query.iter.*;
+import org.basex.query.value.*;
 import org.basex.query.value.node.*;
 import org.basex.server.*;
 import org.basex.server.Log.LogEntry;
@@ -26,6 +27,11 @@
 public final class AdminLogs extends AdminFn {
   @Override
   public Iter iter(final QueryContext qc) throws QueryException {
+    return value(qc).iter();
+  }
+
+  @Override
+  public Value value(final QueryContext qc) throws QueryException {
     checkAdmin(qc);
 
     final ValueBuilder vb = new ValueBuilder();
@@ -72,7 +78,7 @@
         vb.add(elem);
       }
     }
-    return vb;
+    return vb.value();
   }
 
   /**
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/admin/AdminSessions.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/admin/AdminSessions.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/admin/AdminSessions.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/admin/AdminSessions.java	2015-07-14 10:54:40.000000000 +0000
@@ -5,6 +5,7 @@
 import org.basex.data.*;
 import org.basex.query.*;
 import org.basex.query.iter.*;
+import org.basex.query.value.*;
 import org.basex.query.value.node.*;
 import org.basex.server.*;
 
@@ -17,6 +18,11 @@
 public final class AdminSessions extends AdminFn {
   @Override
   public Iter iter(final QueryContext qc) throws QueryException {
+    return value(qc).iter();
+  }
+
+  @Override
+  public Value value(final QueryContext qc) throws QueryException {
     checkAdmin(qc);
 
     final ValueBuilder vb = new ValueBuilder();
@@ -30,6 +36,6 @@
         vb.add(elem);
       }
     }
-    return vb;
+    return vb.value();
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/admin/AdminWriteLog.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/admin/AdminWriteLog.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/admin/AdminWriteLog.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/admin/AdminWriteLog.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,5 +1,8 @@
 package org.basex.query.func.admin;
 
+import static org.basex.query.QueryError.*;
+import static org.basex.util.Token.*;
+
 import org.basex.core.users.*;
 import org.basex.query.*;
 import org.basex.query.value.item.*;
@@ -18,11 +21,14 @@
   public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
     checkAdmin(qc);
 
-    final String msg = Token.string(toToken(exprs[0], qc));
+    final String msg = string(toToken(exprs[0], qc));
+    final String type = exprs.length > 1 ? string(toToken(exprs[1], qc)) : LogType.INFO.toString();
+    if(!type.matches("^[A-Z]+$")) throw BXAD_TYPE_X.get(info, type);
+
     final ClientListener cl = qc.context.listener;
     final String addr = cl == null ? Log.SERVER : cl.address();
     final User user = (cl == null ? qc.context : cl.context()).user();
-    qc.context.log.write(addr, user, LogType.INFO, msg, null);
+    qc.context.log.write(addr, user, type, msg, null);
     return null;
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/archive/ArchiveCreateFrom.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/archive/ArchiveCreateFrom.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/archive/ArchiveCreateFrom.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/archive/ArchiveCreateFrom.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,62 @@
+package org.basex.query.func.archive;
+
+import static org.basex.query.QueryError.*;
+import static org.basex.query.func.archive.ArchiveText.*;
+import static org.basex.util.Token.*;
+
+import java.io.*;
+import java.util.*;
+
+import org.basex.io.*;
+import org.basex.query.*;
+import org.basex.query.iter.*;
+import org.basex.query.value.item.*;
+import org.basex.query.value.seq.*;
+import org.basex.util.*;
+import org.basex.util.list.*;
+
+/**
+ * Function implementation.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Christian Gruen
+ */
+public class ArchiveCreateFrom extends ArchiveCreate {
+  @Override
+  public B64 item(final QueryContext qc, final InputInfo ii) throws QueryException {
+    checkCreate(qc);
+
+    final IOFile root = new IOFile(toPath(0, qc).toString());
+    final ArchOptions opts = toOptions(1, Q_OPTIONS, new ArchOptions(), qc);
+    final Iter entries;
+    if(exprs.length > 2) {
+      entries = qc.iter(exprs[2]);
+    } else {
+      final TokenList tl = new TokenList();
+      for(final String file : root.descendants()) tl.add(file);
+      entries = StrSeq.get(tl).iter();
+    }
+
+    final String format = opts.get(ArchOptions.FORMAT);
+    final int level = level(opts);
+    if(!root.isDir()) throw FILE_NO_DIR_X.get(info, root);
+
+    try(final ArchiveOut out = ArchiveOut.get(format.toLowerCase(Locale.ENGLISH), info)) {
+      out.level(level);
+      try {
+        while(true) {
+          Item en = entries.next();
+          if(en == null) break;
+          en = checkElemToken(en);
+          final IOFile file = new IOFile(root, string(en.string(info)));
+          if(!file.exists()) throw FILE_NOT_FOUND_X.get(info, file);
+          if(file.isDir()) throw FILE_IS_DIR_X.get(info, file);
+          add(en, new B64(file.read()), out, level, qc);
+        }
+      } catch(final IOException ex) {
+        throw ARCH_FAIL_X.get(info, ex);
+      }
+      return new B64(out.finish());
+    }
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/archive/ArchiveCreate.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/archive/ArchiveCreate.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/archive/ArchiveCreate.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/archive/ArchiveCreate.java	2015-07-14 10:54:40.000000000 +0000
@@ -14,7 +14,6 @@
 import org.basex.query.value.item.*;
 import org.basex.query.value.node.*;
 import org.basex.util.*;
-import org.basex.util.options.*;
 
 /**
  * Function implementation.
@@ -25,41 +24,32 @@
 public class ArchiveCreate extends ArchiveFn {
   @Override
   public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
-    final Iter entr = qc.iter(exprs[0]), cont = qc.iter(exprs[1]);
-    final Options opts = toOptions(2, Q_OPTIONS, new ArchOptions(), qc);
+    final Iter entries = qc.iter(exprs[0]), contents = qc.iter(exprs[1]);
+    final ArchOptions opts = toOptions(2, Q_OPTIONS, new ArchOptions(), qc);
 
+    // check options
     final String format = opts.get(ArchOptions.FORMAT);
+    final int level = level(opts);
+
     try(final ArchiveOut out = ArchiveOut.get(format.toLowerCase(Locale.ENGLISH), info)) {
-      // check algorithm
-      final String alg = opts.get(ArchOptions.ALGORITHM);
-      int level = ZipEntry.DEFLATED;
-      if(alg != null) {
-        if(format.equals(ZIP)  && !Strings.eq(alg, STORED, DEFLATE) ||
-           format.equals(GZIP) && !Strings.eq(alg, DEFLATE)) {
-          throw ARCH_SUPP_X_X.get(info, ArchOptions.ALGORITHM.name(), alg);
-        }
-        if(Strings.eq(alg, STORED)) level = ZipEntry.STORED;
-        else if(Strings.eq(alg, DEFLATE)) level = ZipEntry.DEFLATED;
-      }
       out.level(level);
-
       try {
-        Item en, cn;
         int e = 0, c = 0;
         while(true) {
-          en = entr.next();
-          cn = cont.next();
-          if(en == null || cn == null) break;
+          final Item en = entries.next(), cn = contents.next();
+          if(en == null || cn == null) {
+            // count remaining entries
+            if(cn != null) do c++; while(contents.next() != null);
+            if(en != null) do e++; while(entries.next() != null);
+            if(e != c) throw ARCH_DIFF_X_X.get(info, e, c);
+            break;
+          }
           if(out instanceof GZIPOut && c > 0)
             throw ARCH_ONE_X.get(info, format.toUpperCase(Locale.ENGLISH));
           add(checkElemToken(en), cn, out, level, qc);
           e++;
           c++;
         }
-        // count remaining entries
-        if(cn != null) do c++; while(cont.next() != null);
-        if(en != null) do e++; while(entr.next() != null);
-        if(e != c) throw ARCH_DIFF_X_X.get(info, e, c);
       } catch(final IOException ex) {
         throw ARCH_FAIL_X.get(info, ex);
       }
@@ -68,6 +58,27 @@
   }
 
   /**
+   * Returns the compression level.
+   * @param options options
+   * @return level
+   * @throws QueryException query exception
+   */
+  protected int level(final ArchOptions options) throws QueryException {
+    int level = ZipEntry.DEFLATED;
+    final String format = options.get(ArchOptions.FORMAT);
+    final String alg = options.get(ArchOptions.ALGORITHM);
+    if(alg != null) {
+      if(format.equals(ZIP)  && !Strings.eq(alg, STORED, DEFLATE) ||
+         format.equals(GZIP) && !Strings.eq(alg, DEFLATE)) {
+        throw ARCH_SUPP_X_X.get(info, ArchOptions.ALGORITHM.name(), alg);
+      }
+      if(Strings.eq(alg, STORED)) level = ZipEntry.STORED;
+      else if(Strings.eq(alg, DEFLATE)) level = ZipEntry.DEFLATED;
+    }
+    return level;
+  }
+
+  /**
    * Adds the specified entry to the output stream.
    * @param entry entry descriptor
    * @param cont contents
@@ -77,7 +88,7 @@
    * @throws QueryException query exception
    * @throws IOException I/O exception
    */
-  final void add(final Item entry, final Item cont, final ArchiveOut out, final int level,
+  protected final void add(final Item entry, final Item cont, final ArchiveOut out, final int level,
       final QueryContext qc) throws QueryException, IOException {
 
     // create new zip entry
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/archive/ArchiveEntries.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/archive/ArchiveEntries.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/archive/ArchiveEntries.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/archive/ArchiveEntries.java	2015-07-14 10:54:40.000000000 +0000
@@ -10,6 +10,7 @@
 import org.basex.query.*;
 import org.basex.query.func.*;
 import org.basex.query.iter.*;
+import org.basex.query.value.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.node.*;
 
@@ -22,6 +23,11 @@
 public final class ArchiveEntries extends StandardFunc {
   @Override
   public Iter iter(final QueryContext qc) throws QueryException {
+    return value(qc).iter();
+  }
+
+  @Override
+  public Value value(final QueryContext qc) throws QueryException {
     final B64 archive = toB64(exprs[0], qc, false);
     final ValueBuilder vb = new ValueBuilder();
     try(final ArchiveIn in = ArchiveIn.get(archive.input(info), info)) {
@@ -38,7 +44,7 @@
         e.add(ze.getName());
         vb.add(e);
       }
-      return vb;
+      return vb.value();
     } catch(final IOException ex) {
       throw ARCH_FAIL_X.get(info, ex);
     }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/archive/ArchiveExtractBinary.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/archive/ArchiveExtractBinary.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/archive/ArchiveExtractBinary.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/archive/ArchiveExtractBinary.java	2015-07-14 10:54:40.000000000 +0000
@@ -8,6 +8,7 @@
 
 import org.basex.query.*;
 import org.basex.query.iter.*;
+import org.basex.query.value.*;
 import org.basex.query.value.item.*;
 import org.basex.util.hash.*;
 import org.basex.util.list.*;
@@ -21,9 +22,14 @@
 public class ArchiveExtractBinary extends ArchiveFn {
   @Override
   public Iter iter(final QueryContext qc) throws QueryException {
+    return value(qc).iter();
+  }
+
+  @Override
+  public Value value(final QueryContext qc) throws QueryException {
     final ValueBuilder vb = new ValueBuilder();
     for(final byte[] b : extract(qc)) vb.add(new B64(b));
-    return vb;
+    return vb.value();
   }
 
   /**
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/archive/ArchiveExtractText.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/archive/ArchiveExtractText.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/archive/ArchiveExtractText.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/archive/ArchiveExtractText.java	2015-07-14 10:54:40.000000000 +0000
@@ -4,6 +4,7 @@
 
 import org.basex.query.*;
 import org.basex.query.iter.*;
+import org.basex.query.value.*;
 import org.basex.query.value.item.*;
 
 /**
@@ -15,9 +16,14 @@
 public final class ArchiveExtractText extends ArchiveExtractBinary {
   @Override
   public Iter iter(final QueryContext qc) throws QueryException {
+    return value(qc).iter();
+  }
+
+  @Override
+  public Value value(final QueryContext qc) throws QueryException {
     final String enc = toEncoding(2, ARCH_ENCODING_X, qc);
     final ValueBuilder vb = new ValueBuilder();
     for(final byte[] b : extract(qc)) vb.add(Str.get(encode(b, enc, qc)));
-    return vb;
+    return vb.value();
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/archive/ArchiveExtractTo.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/archive/ArchiveExtractTo.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/archive/ArchiveExtractTo.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/archive/ArchiveExtractTo.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,49 @@
+package org.basex.query.func.archive;
+
+import static org.basex.query.QueryError.*;
+import static org.basex.util.Token.*;
+
+import java.io.*;
+import java.nio.file.*;
+import java.util.zip.*;
+
+import org.basex.query.*;
+import org.basex.query.value.item.*;
+import org.basex.util.*;
+import org.basex.util.hash.*;
+
+/**
+ * Function implementation.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Christian Gruen
+ */
+public class ArchiveExtractTo extends ArchiveFn {
+  @Override
+  public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
+    checkCreate(qc);
+
+    final Path path = toPath(0, qc);
+    final B64 archive = toB64(exprs[1], qc, false);
+    final TokenSet hs = entries(2, qc);
+
+    try(final ArchiveIn in = ArchiveIn.get(archive.input(info), info)) {
+      while(in.more()) {
+        final ZipEntry ze = in.entry();
+        final String name = ze.getName();
+        if(hs == null || hs.delete(token(name)) != 0) {
+          final Path file = path.resolve(name);
+          if(ze.isDirectory()) {
+            Files.createDirectories(file);
+          } else {
+            Files.createDirectories(file.getParent());
+            Files.write(file, in.read());
+          }
+        }
+      }
+    } catch(final IOException ex) {
+      throw ARCH_FAIL_X.get(info, ex);
+    }
+    return null;
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/archive/ArchiveWrite.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/archive/ArchiveWrite.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/archive/ArchiveWrite.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/archive/ArchiveWrite.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,16 +1,5 @@
 package org.basex.query.func.archive;
 
-import static org.basex.query.QueryError.*;
-import static org.basex.util.Token.*;
-
-import java.io.*;
-import java.nio.file.*;
-import java.util.zip.*;
-
-import org.basex.query.*;
-import org.basex.query.value.item.*;
-import org.basex.util.*;
-import org.basex.util.hash.*;
 
 /**
  * Function implementation.
@@ -18,32 +7,5 @@
  * @author BaseX Team 2005-15, BSD License
  * @author Christian Gruen
  */
-public final class ArchiveWrite extends ArchiveFn {
-  @Override
-  public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
-    checkCreate(qc);
-
-    final Path path = toPath(0, qc);
-    final B64 archive = toB64(exprs[1], qc, false);
-    final TokenSet hs = entries(2, qc);
-
-    try(final ArchiveIn in = ArchiveIn.get(archive.input(info), info)) {
-      while(in.more()) {
-        final ZipEntry ze = in.entry();
-        final String name = ze.getName();
-        if(hs == null || hs.delete(token(name)) != 0) {
-          final Path file = path.resolve(name);
-          if(ze.isDirectory()) {
-            Files.createDirectories(file);
-          } else {
-            Files.createDirectories(file.getParent());
-            Files.write(file, in.read());
-          }
-        }
-      }
-    } catch(final IOException ex) {
-      throw ARCH_FAIL_X.get(info, ex);
-    }
-    return null;
-  }
+public final class ArchiveWrite extends ArchiveExtractTo {
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/array/ArrayFilter.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/array/ArrayFilter.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/array/ArrayFilter.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/array/ArrayFilter.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,7 +1,5 @@
 package org.basex.query.func.array;
 
-import java.util.*;
-
 import org.basex.query.*;
 import org.basex.query.value.*;
 import org.basex.query.value.array.*;
@@ -21,10 +19,8 @@
     final Array array = toArray(exprs[0], qc);
     final FItem fun = checkArity(exprs[1], 1, qc);
     final ArrayBuilder builder = new ArrayBuilder();
-    final Iterator<Value> iter = array.members();
-    while(iter.hasNext()) {
-      final Value v = iter.next();
-      if(toBoolean(fun.invokeItem(qc, info, v))) builder.append(v);
+    for(final Value val : array.members()) {
+      if(toBoolean(fun.invokeItem(qc, info, val))) builder.append(val);
     }
     return builder.freeze();
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/array/ArrayFlatten.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/array/ArrayFlatten.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/array/ArrayFlatten.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/array/ArrayFlatten.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,7 +1,11 @@
 package org.basex.query.func.array;
 
+import java.util.*;
+
 import org.basex.query.*;
 import org.basex.query.iter.*;
+import org.basex.query.value.*;
+import org.basex.query.value.array.*;
 import org.basex.query.value.item.*;
 
 /**
@@ -9,13 +13,69 @@
  *
  * @author BaseX Team 2005-15, BSD License
  * @author Christian Gruen
+ * @author Leo Woerteler
  */
 public final class ArrayFlatten extends ArrayFn {
   @Override
-  public Iter iter(final QueryContext qc) throws QueryException {
+  public Value value(final QueryContext qc) throws QueryException {
     final ValueBuilder vb = new ValueBuilder();
-    final Iter ir = qc.iter(exprs[0]);
-    for(Item it; (it = ir.next()) != null;) vb.addFlattened(it);
-    return vb;
+    final Iter iter = qc.iter(exprs[0]);
+    for(Item it; (it = iter.next()) != null;) {
+      if(it instanceof Array) addFlattened(vb, (Array) it);
+      else vb.add(it);
+    }
+    return vb.value();
+  }
+
+  /**
+   * Recursive helper method for flattening nested arrays.
+   * @param vb sequence builder
+   * @param arr current array
+   */
+  private static void addFlattened(final ValueBuilder vb, final Array arr) {
+    for(final Value val : arr.members()) {
+      for(final Item it : val) {
+        if(it instanceof Array) addFlattened(vb, (Array) it);
+        else vb.add(it);
+      }
+    }
+  }
+
+  @Override
+  public Iter iter(final QueryContext qc) throws QueryException {
+    return new Iter() {
+      @SuppressWarnings("unchecked")
+      private Iterator<Value>[] iters = new Iterator[2];
+      private int p = -1;
+      private Iter curr = qc.iter(exprs[0]);
+
+      @Override
+      public Item next() throws QueryException {
+        for(;;) {
+          final Item it = curr.next();
+
+          if(it != null) {
+            if(!(it instanceof Array)) return it;
+            final Array arr = (Array) it;
+            if(++p == iters.length) {
+              @SuppressWarnings("unchecked")
+              final Iterator<Value>[] temp = new Iterator[2 * p];
+              System.arraycopy(iters, 0, temp, 0, p);
+              iters = temp;
+            }
+            iters[p] = arr.iterator(0);
+          } else if(p < 0) {
+            return null;
+          }
+
+          while(!iters[p].hasNext()) {
+            iters[p] = null;
+            if(--p < 0) return null;
+          }
+
+          curr = iters[p].next().iter();
+        }
+      }
+    };
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/array/ArrayFoldLeft.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/array/ArrayFoldLeft.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/array/ArrayFoldLeft.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/array/ArrayFoldLeft.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,7 +1,5 @@
 package org.basex.query.func.array;
 
-import java.util.*;
-
 import org.basex.query.*;
 import org.basex.query.iter.*;
 import org.basex.query.value.*;
@@ -25,8 +23,7 @@
     final Array array = toArray(exprs[0], qc);
     Value res = qc.value(exprs[1]);
     final FItem fun = checkArity(exprs[2], 2, qc);
-    final Iterator<Value> iter = array.members();
-    while(iter.hasNext()) res = fun.invokeValue(qc, info, res, iter.next());
+    for(final Value val : array.members()) res = fun.invokeValue(qc, info, res, val);
     return res;
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/array/ArrayFoldRight.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/array/ArrayFoldRight.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/array/ArrayFoldRight.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/array/ArrayFoldRight.java	2015-07-14 10:54:40.000000000 +0000
@@ -25,7 +25,7 @@
     final Array array = toArray(exprs[0], qc);
     Value res = qc.value(exprs[1]);
     final FItem fun = checkArity(exprs[2], 2, qc);
-    final ListIterator<Value> iter = array.members(true);
+    final ListIterator<Value> iter = array.iterator(array.arraySize());
     while(iter.hasPrevious()) res = fun.invokeValue(qc, info, iter.previous(), res);
     return res;
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/array/ArrayForEach.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/array/ArrayForEach.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/array/ArrayForEach.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/array/ArrayForEach.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,7 +1,5 @@
 package org.basex.query.func.array;
 
-import java.util.*;
-
 import org.basex.query.*;
 import org.basex.query.value.*;
 import org.basex.query.value.array.*;
@@ -21,8 +19,7 @@
     final Array array = toArray(exprs[0], qc);
     final FItem fun = checkArity(exprs[1], 1, qc);
     final ArrayBuilder builder = new ArrayBuilder();
-    final Iterator<Value> iter = array.members();
-    while(iter.hasNext()) builder.append(fun.invokeValue(qc, info, iter.next()));
+    for(final Value val : array.members()) builder.append(fun.invokeValue(qc, info, val));
     return builder.freeze();
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/array/ArrayForEachPair.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/array/ArrayForEachPair.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/array/ArrayForEachPair.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/array/ArrayForEachPair.java	2015-07-14 10:54:40.000000000 +0000
@@ -21,7 +21,7 @@
     final Array array1 = toArray(exprs[0], qc), array2 = toArray(exprs[1], qc);
     final FItem fun = checkArity(exprs[2], 2, qc);
     final ArrayBuilder builder = new ArrayBuilder();
-    final Iterator<Value> as = array1.members(), bs = array2.members();
+    final Iterator<Value> as = array1.iterator(0), bs = array2.iterator(0);
     while(as.hasNext() && bs.hasNext())
       builder.append(fun.invokeValue(qc, info, as.next(), bs.next()));
     return builder.freeze();
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/array/ArrayReverse.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/array/ArrayReverse.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/array/ArrayReverse.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/array/ArrayReverse.java	2015-07-14 10:54:40.000000000 +0000
@@ -13,6 +13,6 @@
 public final class ArrayReverse extends ArrayFn {
   @Override
   public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
-    return toArray(exprs[0], qc).reverse();
+    return toArray(exprs[0], qc).reverseArray();
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/array/ArraySort.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/array/ArraySort.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/array/ArraySort.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/array/ArraySort.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,7 +1,5 @@
 package org.basex.query.func.array;
 
-import java.util.*;
-
 import org.basex.query.*;
 import org.basex.query.func.*;
 import org.basex.query.func.fn.*;
@@ -21,22 +19,21 @@
 public final class ArraySort extends StandardFunc {
   @Override
   public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
-    final Array value = toArray(exprs[0], qc);
+    final Array array = toArray(exprs[0], qc);
 
-    final int sz = (int) value.arraySize();
+    final int sz = (int) array.arraySize();
     final ValueList vl = new ValueList(sz);
-    final Iterator<Value> iter = value.members();
     if(exprs.length > 1) {
       final FItem key = checkArity(exprs[1], 1, qc);
-      while(iter.hasNext()) vl.add(key.invokeValue(qc, info, iter.next()));
+      for(final Value val : array.members()) vl.add(key.invokeValue(qc, info, val));
     } else {
-      while(iter.hasNext()) vl.add(iter.next());
+      for(final Value val : array.members()) vl.add(val);
     }
 
     final Integer[] order = FnSort.sort(vl, this);
     final ArrayBuilder builder = new ArrayBuilder();
     if(exprs.length > 1) {
-      for(int r = 0; r < sz; r++) builder.append(value.get(order[r]));
+      for(int r = 0; r < sz; r++) builder.append(array.get(order[r]));
     } else {
       for(int r = 0; r < sz; r++) builder.append(vl.get(order[r]));
     }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/crypto/CryptoGenerateSignature.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/crypto/CryptoGenerateSignature.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/crypto/CryptoGenerateSignature.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/crypto/CryptoGenerateSignature.java	2015-07-14 10:54:40.000000000 +0000
@@ -6,7 +6,6 @@
 import org.basex.query.func.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.node.*;
-import org.basex.query.value.type.*;
 import org.basex.util.*;
 
 /**
@@ -22,10 +21,13 @@
     Item arg6 = null;
     boolean arg6Str = false;
     if(exprs.length > 6) {
-      arg6 = toItem(exprs[6], qc);
-      if(arg6 instanceof AStr) arg6Str = true;
-      else if(!(arg6 instanceof ANode)) throw castError(info, arg6, AtomType.STR);
+      arg6 = toNodeOrAtomItem(exprs[6], qc);
+      if(!(arg6 instanceof ANode)) {
+        if(!arg6.type.isStringOrUntyped()) throw STRNOD_X_X.get(info, arg6.type, arg6);
+        arg6Str = true;
+      }
     }
+
     return new DigitalSignature(ii).generateSignature(
         toNode(exprs[0], qc), toToken(exprs[1], qc),
         toToken(exprs[2], qc), toToken(exprs[3], qc),
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/db/DbAdd.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/db/DbAdd.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/db/DbAdd.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/db/DbAdd.java	2015-07-14 10:54:40.000000000 +0000
@@ -21,7 +21,7 @@
   public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
     final Data data = checkData(qc);
     final byte[] path = exprs.length < 3 ? EMPTY : token(path(2, qc));
-    final NewInput input = checkInput(toItem(exprs[1], qc), path);
+    final NewInput input = checkInput(toNodeOrAtomItem(exprs[1], qc), path);
     final Options opts = toOptions(3, Q_OPTIONS, new Options(), qc);
     qc.resources.updates().add(new DBAdd(data, input, opts, qc, info), qc);
     return null;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/db/DbBackups.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/db/DbBackups.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/db/DbBackups.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/db/DbBackups.java	2015-07-14 10:54:40.000000000 +0000
@@ -2,12 +2,16 @@
 
 import static org.basex.util.Token.*;
 
+import java.util.*;
+
+import org.basex.core.*;
 import org.basex.io.*;
 import org.basex.query.*;
 import org.basex.query.func.*;
 import org.basex.query.iter.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.node.*;
+import org.basex.util.*;
 import org.basex.util.list.*;
 
 /**
@@ -17,10 +21,14 @@
  * @author Christian Gruen
  */
 public final class DbBackups extends StandardFunc {
-  /** Backup element name. */
+  /** Backup string. */
   private static final String BACKUP = "backup";
-  /** Size element name. */
+  /** Size string. */
   private static final String SIZE = "size";
+  /** Date string. */
+  private static final String DATE = "date";
+  /** Database string. */
+  private static final String DATABASE = "database";
 
   @Override
   public Iter iter(final QueryContext qc) throws QueryException {
@@ -34,11 +42,19 @@
       int up = -1;
 
       @Override
-      public Item next() {
+      public Item next() throws QueryException {
         if(++up >= backups.size()) return null;
         final String backup = backups.get(up);
         final long length = new IOFile(dbpath, backup + IO.ZIPSUFFIX).length();
-        return new FElem(BACKUP).add(backup).add(SIZE, token(length));
+        final String db = Databases.name(backup);
+
+        final Date date = Databases.date(backup);
+        final String ymd = DateTime.format(date, DateTime.DATE);
+        final String hms = DateTime.format(date, DateTime.TIME);
+        final Dtm dtm = new Dtm(token(ymd + 'T' + hms), info);
+
+        return new FElem(BACKUP).add(backup).add(DATABASE, db).add(DATE, dtm.string(info)).
+            add(SIZE, token(length));
       }
     };
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/db/DbEvent.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/db/DbEvent.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/db/DbEvent.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/db/DbEvent.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,32 +0,0 @@
-package org.basex.query.func.db;
-
-import static org.basex.query.QueryError.*;
-
-import org.basex.io.out.*;
-import org.basex.io.serial.*;
-import org.basex.query.*;
-import org.basex.query.func.*;
-import org.basex.query.value.item.*;
-import org.basex.util.*;
-
-/**
- * Function implementation.
- *
- * @author BaseX Team 2005-15, BSD License
- * @author Christian Gruen
- */
-public final class DbEvent extends StandardFunc {
-  @Override
-  public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
-    final byte[] name = toToken(exprs[0], qc);
-    try {
-      final ArrayOutput ao = qc.value(exprs[1]).serialize(SerializerOptions.get(false));
-      // throw exception if event is unknown
-      if(!qc.context.events.notify(qc.context, name, ao.finish()))
-        throw BXDB_EVENT_X.get(info, name);
-      return null;
-    } catch(final QueryIOException ex) {
-      throw ex.getCause(info);
-    }
-  }
-}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/db/DbListDetails.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/db/DbListDetails.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/db/DbListDetails.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/db/DbListDetails.java	2015-07-14 10:54:40.000000000 +0000
@@ -56,8 +56,10 @@
       @Override
       public ANode get(final long i) {
         if(i < is) {
-          final byte[] pt = data.text(il.get((int) i), true);
-          return resource(pt, false, 0, MediaType.APPLICATION_XML, data.meta.time);
+          final int pre = il.get((int) i);
+          final byte[] pt = data.text(pre, true);
+          return resource(pt, false, data.size(pre, Data.DOC), MediaType.APPLICATION_XML,
+              data.meta.time);
         }
         if(i < is + ts) {
           final byte[] pt = tl.get((int) i - is);
@@ -71,7 +73,7 @@
         return ip < is ? get(ip++) : tp < ts ? get(ip + tp++) : null;
       }
       @Override
-      public long size() { return ip + is; }
+      public long size() { return is + ts; }
     };
   }
 
@@ -88,20 +90,21 @@
       @Override
       public ANode get(final long i) throws QueryException {
         final String name = dbs.get((int) i);
-        final MetaData meta = new MetaData(name, ctx.options, ctx.soptions);
         try {
+          final MetaData meta = new MetaData(name, ctx.options, ctx.soptions);
           meta.read();
+          // count number of raw files
+          final int bin = new IOFile(ctx.soptions.dbpath(name), IO.RAW).descendants().size();
+          final FElem res = new FElem(DATABASE);
+          res.add(RESOURCES, token(meta.ndocs + bin));
+          res.add(MDATE, DateTime.format(new Date(meta.dbtime())));
+          res.add(SIZE, token(meta.dbsize()));
+          if(ctx.perm(Perm.CREATE, name)) res.add(PATH, meta.original);
+          res.add(name);
+          return res;
         } catch(final IOException ex) {
           throw BXDB_OPEN_X.get(info, ex);
         }
-
-        final FElem res = new FElem(DATABASE);
-        res.add(RESOURCES, token(meta.ndocs));
-        res.add(MDATE, DateTime.format(new Date(meta.dbtime()), DateTime.FULL));
-        res.add(SIZE, token(meta.dbsize()));
-        if(ctx.perm(Perm.CREATE, name)) res.add(PATH, meta.original);
-        res.add(name);
-        return res;
       }
       @Override
       public ANode next() throws QueryException { return pos < size() ? get(pos++) : null; }
@@ -122,9 +125,8 @@
   private static FNode resource(final byte[] path, final boolean raw, final long size,
       final MediaType type, final long mdate) {
 
-    final String tstamp = DateTime.format(new Date(mdate), DateTime.FULL);
-    final FElem res = new FElem(RESOURCE).add(path).
-        add(RAW, token(raw)).add(CTYPE, type.toString()).add(MDATE, tstamp);
-    return raw ? res.add(SIZE, token(size)) : res;
+    final String tstamp = DateTime.format(new Date(mdate));
+    return new FElem(RESOURCE).add(path).
+        add(RAW, token(raw)).add(CTYPE, type.toString()).add(MDATE, tstamp).add(SIZE, token(size));
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/db/DbName.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/db/DbName.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/db/DbName.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/db/DbName.java	2015-07-14 10:54:40.000000000 +0000
@@ -13,6 +13,6 @@
 public final class DbName extends DbAccess {
   @Override
   public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
-    return Str.get(toDBNode(toNode(exprs[0], qc)).data.meta.name);
+    return Str.get(toDBNode(toNode(exprs[0], qc)).data().meta.name);
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/db/DbNew.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/db/DbNew.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/db/DbNew.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/db/DbNew.java	2015-07-14 10:54:40.000000000 +0000
@@ -24,7 +24,7 @@
 
   /**
    * Creates a {@link Data} instance for the specified document.
-   * @param in input item
+   * @param in input item (node or string)
    * @param path optional path argument
    * @return database instance
    * @throws QueryException query exception
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/db/DbNodeId.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/db/DbNodeId.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/db/DbNodeId.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/db/DbNodeId.java	2015-07-14 10:54:40.000000000 +0000
@@ -23,7 +23,7 @@
         final Item it = ir.next();
         if(it == null) return null;
         final DBNode node = toDBNode(it);
-        return Int.get(node.data.id(node.pre));
+        return Int.get(node.data().id(node.pre()));
       }
     };
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/db/DbNodePre.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/db/DbNodePre.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/db/DbNodePre.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/db/DbNodePre.java	2015-07-14 10:54:40.000000000 +0000
@@ -20,7 +20,7 @@
       @Override
       public Int next() throws QueryException {
         final Item it = ir.next();
-        return it == null ? null : Int.get(toDBNode(it).pre);
+        return it == null ? null : Int.get(toDBNode(it).pre());
       }
     };
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/db/DbOutputCache.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/db/DbOutputCache.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/db/DbOutputCache.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/db/DbOutputCache.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,24 @@
+package org.basex.query.func.db;
+
+import org.basex.query.*;
+import org.basex.query.func.*;
+import org.basex.query.iter.*;
+import org.basex.query.value.*;
+
+/**
+ * Function implementation.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Christian Gruen
+ */
+public final class DbOutputCache extends StandardFunc {
+  @Override
+  public Value value(final QueryContext qc) throws QueryException {
+    return qc.resources.output.value();
+  }
+
+  @Override
+  public Iter iter(final QueryContext qc) throws QueryException {
+    return value(qc).iter();
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/db/DbPath.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/db/DbPath.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/db/DbPath.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/db/DbPath.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,5 +1,6 @@
 package org.basex.query.func.db;
 
+import org.basex.data.*;
 import org.basex.query.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.node.*;
@@ -13,13 +14,13 @@
  */
 public final class DbPath extends DbAccess {
   @Override
-  public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
+  public Str item(final QueryContext qc, final InputInfo ii) throws QueryException {
     ANode node, par = toNode(exprs[0], qc);
     do {
       node = par;
       par = node.parent();
     } while(par != null);
     final DBNode dbn = toDBNode(node);
-    return Str.get(dbn.data.text(dbn.pre, true));
+    return dbn.kind() == Data.DOC ? Str.get(dbn.data().text(dbn.pre(), true)) : Str.ZERO;
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/db/DbReplace.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/db/DbReplace.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/db/DbReplace.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/db/DbReplace.java	2015-07-14 10:54:40.000000000 +0000
@@ -26,7 +26,7 @@
   public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
     final Data data = checkData(qc);
     final String path = path(1, qc);
-    final Item item = toItem(exprs[2], qc);
+    final Item item = toNodeOrAtomItem(exprs[2], qc);
     final Options opts = toOptions(3, Q_OPTIONS, new Options(), qc);
 
     final Updates updates = qc.resources.updates();
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/db/DbStore.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/db/DbStore.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/db/DbStore.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/db/DbStore.java	2015-07-14 10:54:40.000000000 +0000
@@ -20,7 +20,7 @@
   public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
     final Data data = checkData(qc);
     final String path = path(1, qc);
-    final Item item = toItem(exprs[2], qc);
+    final Item item = toNodeOrAtomItem(exprs[2], qc);
     if(data.inMemory()) throw BXDB_MEM_X.get(info, data.meta.name);
 
     final IOFile file = data.meta.binary(path);
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/file/FileCopy.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/file/FileCopy.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/file/FileCopy.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/file/FileCopy.java	2015-07-14 10:54:40.000000000 +0000
@@ -49,11 +49,7 @@
     }
 
     // ignore operations on identical, canonical source and target path
-    if(copy) {
-      copy(src, trg);
-    } else {
-      Files.move(src, trg, StandardCopyOption.REPLACE_EXISTING);
-    }
+    relocate(src, trg, copy);
     return null;
   }
 
@@ -61,16 +57,22 @@
    * Recursively copies files.
    * @param src source path
    * @param trg target path
+   * @param copy copy flag
    * @throws IOException I/O exception
    */
-  private synchronized void copy(final Path src, final Path trg) throws IOException {
+  private synchronized void relocate(final Path src, final Path trg, final boolean copy)
+      throws IOException {
+
     if(Files.isDirectory(src)) {
       Files.createDirectory(trg);
       try(DirectoryStream<Path> paths = Files.newDirectoryStream(src)) {
-        for(final Path p : paths) copy(p, trg.resolve(p.getFileName()));
+        for(final Path p : paths) relocate(p, trg.resolve(p.getFileName()), copy);
       }
-    } else {
+      if(!copy) Files.delete(src);
+    } else if(copy) {
       Files.copy(src, trg, StandardCopyOption.REPLACE_EXISTING);
+    } else {
+      Files.move(src, trg, StandardCopyOption.REPLACE_EXISTING);
     }
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/file/FileIsAbsolute.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/file/FileIsAbsolute.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/file/FileIsAbsolute.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/file/FileIsAbsolute.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,17 @@
+package org.basex.query.func.file;
+
+import org.basex.query.*;
+import org.basex.query.value.item.*;
+
+/**
+ * Function implementation.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Christian Gruen
+ */
+public final class FileIsAbsolute extends FileFn {
+  @Override
+  public Item item(final QueryContext qc) throws QueryException {
+    return Bln.get(toPath(0, qc).isAbsolute());
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/file/FileResolvePath.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/file/FileResolvePath.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/file/FileResolvePath.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/file/FileResolvePath.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,5 +1,7 @@
 package org.basex.query.func.file;
 
+import static org.basex.query.QueryError.*;
+
 import java.nio.file.*;
 
 import org.basex.query.*;
@@ -14,7 +16,15 @@
 public final class FileResolvePath extends FileFn {
   @Override
   public Item item(final QueryContext qc) throws QueryException {
-    final Path abs = absolute(toPath(0, qc));
+    final Path path = toPath(0, qc);
+    final Path abs;
+    if(exprs.length < 2) {
+      abs = absolute(path);
+    } else {
+      final Path base = toPath(1, qc);
+      if(!base.isAbsolute()) throw FILE_IS_RELATIVE_X.get(info, base);
+      abs = base.resolve(path);
+    }
     return get(abs, Files.isDirectory(abs));
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/Compare.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/Compare.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/Compare.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/Compare.java	2015-07-14 10:54:40.000000000 +0000
@@ -117,9 +117,9 @@
 
       ANode s1 = (ANode) it1, s2 = (ANode) it2;
       if(s1.is(s2)) continue;
-      AxisIter ch1 = s1.children(), ch2 = s2.children();
+      BasicNodeIter ch1 = s1.children(), ch2 = s2.children();
 
-      final Stack<AxisIter> stack = new Stack<>();
+      final Stack<BasicNodeIter> stack = new Stack<>();
       stack.push(ch1);
       stack.push(ch2);
 
@@ -163,12 +163,12 @@
             if(s1.attributes().value().size() != s2.attributes().value().size()) return false;
 
             // compare names, values and prefixes
-            final AxisIter ai1 = s1.attributes();
+            final BasicNodeIter ir1 = s1.attributes();
             LOOP:
-            for(ANode a1; (a1 = ai1.next()) != null;) {
+            for(ANode a1; (a1 = ir1.next()) != null;) {
               n1 = a1.qname();
-              final AxisIter ai2 = s2.attributes();
-              for(ANode a2; (a2 = ai2.next()) != null;) {
+              final BasicNodeIter ir2 = s2.attributes();
+              for(ANode a2; (a2 = ir2.next()) != null;) {
                 n2 = a2.qname();
                 if(!n1.eq(n2)) continue;
                 if(flags.contains(Mode.NAMESPACES) && !eq(n1.prefix(), n2.prefix()) ||
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnApply.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnApply.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnApply.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnApply.java	2015-07-14 10:54:40.000000000 +0000
@@ -2,8 +2,6 @@
 
 import static org.basex.query.QueryError.*;
 
-import java.util.*;
-
 import org.basex.query.*;
 import org.basex.query.func.*;
 import org.basex.query.iter.*;
@@ -32,8 +30,7 @@
     if(fun.arity() != as) throw APPLY_X_X.get(info, fun.arity(), as);
 
     final ValueList vl = new ValueList((int) as);
-    final Iterator<Value> iter = array.members();
-    while(iter.hasNext()) vl.add(iter.next());
+    for(final Value val : array.members()) vl.add(val);
     return fun.invokeValue(qc, info, vl.finish());
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnAvailableEnvironmentVariables.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnAvailableEnvironmentVariables.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnAvailableEnvironmentVariables.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnAvailableEnvironmentVariables.java	2015-07-14 10:54:40.000000000 +0000
@@ -3,6 +3,7 @@
 import org.basex.query.*;
 import org.basex.query.func.*;
 import org.basex.query.iter.*;
+import org.basex.query.value.*;
 import org.basex.query.value.item.*;
 
 /**
@@ -13,9 +14,14 @@
  */
 public final class FnAvailableEnvironmentVariables extends StandardFunc {
   @Override
-  public Iter iter(final QueryContext qc) {
+  public Iter iter(final QueryContext qc) throws QueryException {
+    return value(qc).iter();
+  }
+
+  @Override
+  public Value value(final QueryContext qc) {
     final ValueBuilder vb = new ValueBuilder();
     for(final Object k : System.getenv().keySet()) vb.add(Str.get(k.toString()));
-    return vb;
+    return vb.value();
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnBaseUri.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnBaseUri.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnBaseUri.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnBaseUri.java	2015-07-14 10:54:40.000000000 +0000
@@ -20,7 +20,7 @@
 public final class FnBaseUri extends StandardFunc {
   @Override
   public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
-    final ANode node = toEmptyNode(arg(0, qc), qc);
+    final ANode node = toEmptyNode(ctxArg(0, qc), qc);
     if(node == null) return null;
     if(node.type != NodeType.ELM && node.type != NodeType.DOC && node.parent() == null) return null;
 
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnCurrentDateTime.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnCurrentDateTime.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnCurrentDateTime.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnCurrentDateTime.java	2015-07-14 10:54:40.000000000 +0000
@@ -14,6 +14,6 @@
 public final class FnCurrentDateTime extends StandardFunc {
   @Override
   public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
-    return qc.initDateTime().dtm;
+    return qc.initDateTime().datm;
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnData.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnData.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnData.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnData.java	2015-07-14 10:54:40.000000000 +0000
@@ -19,23 +19,21 @@
 public final class FnData extends StandardFunc {
   @Override
   public Iter iter(final QueryContext qc) throws QueryException {
-    return arg(0, qc).atomIter(qc, info);
+    return ctxArg(0, qc).atomIter(qc, info);
   }
 
   @Override
   public Value value(final QueryContext qc) throws QueryException {
-    return arg(0, qc).atomValue(qc, info);
+    return ctxArg(0, qc).atomValue(qc, info);
   }
 
   @Override
   protected Expr opt(final QueryContext qc, final VarScope scp) {
-    if(exprs.length == 1) {
-      final SeqType st = exprs[0].seqType();
-      if(st.type instanceof NodeType) {
-        seqType = SeqType.get(AtomType.ATM, st.occ);
-      } else if(!st.mayBeArray()) {
-        seqType = st;
-      }
+    final SeqType st = (exprs.length > 0 ? exprs[0] : qc.value != null ? qc.value : this).seqType();
+    if(st.type instanceof NodeType) {
+      seqType = SeqType.get(AtomType.ATM, st.occ);
+    } else if(!st.mayBeArray()) {
+      seqType = st;
     }
     return this;
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnDistinctValues.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnDistinctValues.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnDistinctValues.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnDistinctValues.java	2015-07-14 10:54:40.000000000 +0000
@@ -97,7 +97,7 @@
       for(final byte[] c : pn.stats.cats) is.put(new Atm(c), info);
     }
     // return resulting sequence
-    final ValueBuilder vb = new ValueBuilder(is.size());
+    final ValueBuilder vb = new ValueBuilder();
     for(final Item i : is) vb.add(i);
     return vb.value();
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnDocumentUri.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnDocumentUri.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnDocumentUri.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnDocumentUri.java	2015-07-14 10:54:40.000000000 +0000
@@ -18,7 +18,7 @@
 public final class FnDocumentUri extends StandardFunc {
   @Override
   public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
-    final ANode node = toEmptyNode(arg(0, qc), qc);
+    final ANode node = toEmptyNode(ctxArg(0, qc), qc);
     if(node == null || node.type != NodeType.DOC) return null;
     final byte[] uri = node.baseURI();
     return uri.length == 0 ? null : Uri.uri(uri, false);
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnElementWithId.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnElementWithId.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnElementWithId.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnElementWithId.java	2015-07-14 10:54:40.000000000 +0000
@@ -11,9 +11,7 @@
  */
 public final class FnElementWithId extends Ids {
   @Override
-  public Iter iter(final QueryContext qc) throws QueryException {
-    final NodeSeqBuilder nc = new NodeSeqBuilder().check();
-    add(ids(exprs[0].atomIter(qc, info)), nc, checkRoot(toNode(arg(1, qc), qc)), false);
-    return nc;
+  public BasicNodeIter iter(final QueryContext qc) throws QueryException {
+    return ids(qc, false);
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnFoldLeft.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnFoldLeft.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnFoldLeft.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnFoldLeft.java	2015-07-14 10:54:40.000000000 +0000
@@ -16,6 +16,15 @@
  */
 public final class FnFoldLeft extends StandardFunc {
   @Override
+  public Value value(final QueryContext qc) throws QueryException {
+    final Iter ir = exprs[0].iter(qc);
+    final FItem fun = checkArity(exprs[2], 2, qc);
+    Value res = qc.value(exprs[1]);
+    for(Item it; (it = ir.next()) != null;) res = fun.invokeValue(qc, info, res, it);
+    return res;
+  }
+
+  @Override
   public Iter iter(final QueryContext qc) throws QueryException {
     final Iter ir = exprs[0].iter(qc);
     final FItem fun = checkArity(exprs[2], 2, qc);
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnFoldRight.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnFoldRight.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnFoldRight.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnFoldRight.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,11 +1,14 @@
 package org.basex.query.func.fn;
 
+import java.util.*;
+
 import org.basex.query.*;
 import org.basex.query.expr.*;
 import org.basex.query.func.*;
 import org.basex.query.iter.*;
 import org.basex.query.value.*;
 import org.basex.query.value.item.*;
+import org.basex.query.value.seq.tree.*;
 import org.basex.query.var.*;
 
 /**
@@ -16,6 +19,20 @@
  */
 public final class FnFoldRight extends StandardFunc {
   @Override
+  public Value value(final QueryContext qc) throws QueryException {
+    final Value v = qc.value(exprs[0]);
+    Value res = qc.value(exprs[1]);
+    final FItem fun = checkArity(exprs[2], 2, qc);
+    if(v instanceof TreeSeq) {
+      final ListIterator<Item> iter = ((TreeSeq) v).iterator(v.size());
+      while(iter.hasPrevious()) res = fun.invokeValue(qc, info, iter.previous(), res);
+    } else {
+      for(long i = v.size(); --i >= 0;) res = fun.invokeValue(qc, info, v.itemAt(i), res);
+    }
+    return res;
+  }
+
+  @Override
   public Iter iter(final QueryContext qc) throws QueryException {
     final Value v = qc.value(exprs[0]);
     final FItem fun = checkArity(exprs[2], 2, qc);
@@ -24,7 +41,12 @@
     if(v.isEmpty()) return exprs[1].iter(qc);
 
     Value res = qc.value(exprs[1]);
-    for(long i = v.size(); --i >= 0;) res = fun.invokeValue(qc, info, v.itemAt(i), res);
+    if(v instanceof TreeSeq) {
+      final ListIterator<Item> iter = ((TreeSeq) v).iterator(v.size());
+      while(iter.hasPrevious()) res = fun.invokeValue(qc, info, iter.previous(), res);
+    } else {
+      for(long i = v.size(); --i >= 0;) res = fun.invokeValue(qc, info, v.itemAt(i), res);
+    }
     return res.iter();
   }
 
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnForEach.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnForEach.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnForEach.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnForEach.java	2015-07-14 10:54:40.000000000 +0000
@@ -40,6 +40,23 @@
   }
 
   @Override
+  public Value value(final QueryContext qc) throws QueryException {
+    final FItem f = checkArity(exprs[1], 1, qc);
+    final Iter iter = exprs[0].iter(qc);
+    Item it = iter.next();
+    if(it == null) return Empty.SEQ;
+    final Value v1 = f.invokeValue(qc, info, it);
+    it = iter.next();
+    if(it == null) return v1;
+
+    final ValueBuilder vb = new ValueBuilder().add(v1);
+    do {
+      vb.add(f.invokeValue(qc, info, it));
+    } while((it = iter.next()) != null);
+    return vb.value();
+  }
+
+  @Override
   protected Expr opt(final QueryContext qc, final VarScope scp) throws QueryException {
     if(allAreValues() && exprs[0].size() < UNROLL_LIMIT) {
       // unroll the loop
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnGenerateId.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnGenerateId.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnGenerateId.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnGenerateId.java	2015-07-14 10:54:40.000000000 +0000
@@ -17,7 +17,7 @@
 public final class FnGenerateId extends StandardFunc {
   @Override
   public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
-    final ANode node = toEmptyNode(arg(0, qc), qc);
+    final ANode node = toEmptyNode(ctxArg(0, qc), qc);
     return node == null ? Str.ZERO :
       Str.get(new TokenBuilder(QueryText.ID).addInt(node.id).finish());
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnHasChildren.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnHasChildren.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnHasChildren.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnHasChildren.java	2015-07-14 10:54:40.000000000 +0000
@@ -17,7 +17,7 @@
 public final class FnHasChildren extends StandardFunc {
   @Override
   public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
-    final ANode node = toEmptyNode(arg(0, qc), qc);
+    final ANode node = toEmptyNode(ctxArg(0, qc), qc);
     return Bln.get(node != null && node.hasChildren());
   }
 
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnId.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnId.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnId.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnId.java	2015-07-14 10:54:40.000000000 +0000
@@ -11,9 +11,7 @@
  */
 public final class FnId extends Ids {
   @Override
-  public Iter iter(final QueryContext qc) throws QueryException {
-    final NodeSeqBuilder nc = new NodeSeqBuilder().check();
-    add(ids(exprs[0].atomIter(qc, info)), nc, checkRoot(toNode(arg(1, qc), qc)), false);
-    return nc;
+  public BasicNodeIter iter(final QueryContext qc) throws QueryException {
+    return ids(qc, false);
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnIdref.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnIdref.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnIdref.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnIdref.java	2015-07-14 10:54:40.000000000 +0000
@@ -11,9 +11,7 @@
  */
 public final class FnIdref extends Ids {
   @Override
-  public Iter iter(final QueryContext qc) throws QueryException {
-    final NodeSeqBuilder nb = new NodeSeqBuilder().check();
-    add(ids(exprs[0].atomIter(qc, info)), nb, checkRoot(toNode(arg(1, qc), qc)), true);
-    return nb;
+  public BasicNodeIter iter(final QueryContext qc) throws QueryException {
+    return ids(qc, true);
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnInScopePrefixes.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnInScopePrefixes.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnInScopePrefixes.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnInScopePrefixes.java	2015-07-14 10:54:40.000000000 +0000
@@ -6,6 +6,7 @@
 import org.basex.query.*;
 import org.basex.query.func.*;
 import org.basex.query.iter.*;
+import org.basex.query.value.*;
 import org.basex.query.value.item.*;
 import org.basex.util.*;
 
@@ -18,13 +19,18 @@
 public final class FnInScopePrefixes extends StandardFunc {
   @Override
   public Iter iter(final QueryContext qc) throws QueryException {
+    return value(qc).iter();
+  }
+
+  @Override
+  public Value value(final QueryContext qc) throws QueryException {
     final Atts ns = toElem(exprs[0], qc).nsScope(sc).add(XML, XML_URI);
     final int as = ns.size();
-    final ValueBuilder vb = new ValueBuilder(as);
+    final ValueBuilder vb = new ValueBuilder();
     for(int a = 0; a < as; ++a) {
       final byte[] key = ns.name(a);
       if(key.length + ns.value(a).length != 0) vb.add(Str.get(key));
     }
-    return vb;
+    return vb.value();
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnInsertBefore.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnInsertBefore.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnInsertBefore.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnInsertBefore.java	2015-07-14 10:54:40.000000000 +0000
@@ -3,7 +3,9 @@
 import org.basex.query.*;
 import org.basex.query.func.*;
 import org.basex.query.iter.*;
+import org.basex.query.value.*;
 import org.basex.query.value.item.*;
+import org.basex.query.value.seq.*;
 
 /**
  * Function implementation.
@@ -15,22 +17,39 @@
   @Override
   public Iter iter(final QueryContext qc) throws QueryException {
     return new Iter() {
-      final long pos = Math.max(1, toLong(exprs[1], qc));
       final Iter iter = exprs[0].iter(qc);
+      final long pos = Math.max(1, toLong(exprs[1], qc));
       final Iter ins = exprs[2].iter(qc);
       long p = pos;
       boolean last;
 
       @Override
       public Item next() throws QueryException {
-        if(last) return p > 0 ? ins.next() : null;
-        final boolean sub = p == 0 || --p == 0;
-        final Item i = (sub ? ins : iter).next();
-        if(i != null) return i;
-        if(sub) --p;
-        else last = true;
-        return next();
+        while(!last) {
+          final boolean sub = p == 0 || --p == 0;
+          final Item i = (sub ? ins : iter).next();
+          if(i != null) return i;
+          if(sub) --p;
+          else last = true;
+        }
+        return p > 0 ? ins.next() : null;
       }
     };
   }
+
+  @Override
+  public Value value(final QueryContext qc) throws QueryException {
+    final Value val = exprs[0].value(qc);
+    final long pos = toLong(exprs[1], qc);
+    final Value sub = exprs[2].value(qc);
+
+    final long vs = val.size();
+    final long p = Math.min(Math.max(0, pos - 1), vs);
+
+    // prepend, append or insert new value
+    if(p == 0)  return ValueBuilder.concat(sub, val);
+    if(p == vs) return ValueBuilder.concat(val, sub);
+    return ((Seq) val).insertBefore(p, sub);
+  }
 }
+
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnJsonDoc.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnJsonDoc.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnJsonDoc.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnJsonDoc.java	2015-07-14 10:54:40.000000000 +0000
@@ -13,6 +13,7 @@
 public final class FnJsonDoc extends FnParseJson {
   @Override
   public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
-    return parse(unparsedText(qc, false).string(ii), qc, ii);
+    final Item it = unparsedText(qc, false, false);
+    return it == null ? null : parse(it.string(ii), false, qc, ii);
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnJsonToXml.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnJsonToXml.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnJsonToXml.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnJsonToXml.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,20 @@
+package org.basex.query.func.fn;
+
+import org.basex.query.*;
+import org.basex.query.value.item.*;
+import org.basex.util.*;
+
+/**
+ * Function implementation.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Christian Gruen
+ */
+public class FnJsonToXml extends FnParseJson {
+  @Override
+  public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
+    final Item it = exprs[0].atomItem(qc, info);
+    if(it == null) return null;
+    return parse(toToken(it), true, qc, ii);
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnLang.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnLang.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnLang.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnLang.java	2015-07-14 10:54:40.000000000 +0000
@@ -19,9 +19,9 @@
   @Override
   public Bln item(final QueryContext qc, final InputInfo ii) throws QueryException {
     final byte[] lang = lc(toEmptyToken(exprs[0], qc));
-    final ANode node = toNode(arg(1, qc), qc);
+    final ANode node = toNode(ctxArg(1, qc), qc);
     for(ANode n = node; n != null; n = n.parent()) {
-      final AxisIter atts = n.attributes();
+      final BasicNodeIter atts = n.attributes();
       for(ANode at; (at = atts.next()) != null;) {
         if(eq(at.qname().string(), LANG)) {
           final byte[] ln = lc(normalize(at.string()));
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnLocalName.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnLocalName.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnLocalName.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnLocalName.java	2015-07-14 10:54:40.000000000 +0000
@@ -17,7 +17,7 @@
 public final class FnLocalName extends StandardFunc {
   @Override
   public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
-    final ANode node = toEmptyNode(arg(0, qc), qc);
+    final ANode node = toEmptyNode(ctxArg(0, qc), qc);
     final QNm qname = node != null ? node.qname() : null;
     return qname != null ? Str.get(qname.local()) : Str.ZERO;
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnName.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnName.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnName.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnName.java	2015-07-14 10:54:40.000000000 +0000
@@ -17,7 +17,7 @@
 public final class FnName extends StandardFunc {
   @Override
   public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
-    final ANode node = toEmptyNode(arg(0, qc), qc);
+    final ANode node = toEmptyNode(ctxArg(0, qc), qc);
     final QNm qname = node != null ? node.qname() : null;
     return qname != null ? Str.get(qname.string()) : Str.ZERO;
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnNamespaceUriForPrefix.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnNamespaceUriForPrefix.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnNamespaceUriForPrefix.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnNamespaceUriForPrefix.java	2015-07-14 10:54:40.000000000 +0000
@@ -22,7 +22,6 @@
     final ANode an = toElem(exprs[1], qc);
     if(eq(pref, XML)) return Uri.uri(XML_URI, false);
     final Atts at = an.nsScope(sc);
-    sc.ns.inScope(at);
     final byte[] s = at.value(pref);
     return s == null || s.length == 0 ? null : Uri.uri(s, false);
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnNamespaceUriFromQName.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnNamespaceUriFromQName.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnNamespaceUriFromQName.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnNamespaceUriFromQName.java	2015-07-14 10:54:40.000000000 +0000
@@ -16,7 +16,7 @@
 public final class FnNamespaceUriFromQName extends StandardFunc {
   @Override
   public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
-    final QNm qnm = toQNm(arg(0, qc), qc, true);
+    final QNm qnm = toQNm(ctxArg(0, qc), qc, true);
     return qnm == null ? null : Uri.uri(qnm.uri());
   }
 
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnNamespaceUri.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnNamespaceUri.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnNamespaceUri.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnNamespaceUri.java	2015-07-14 10:54:40.000000000 +0000
@@ -17,7 +17,7 @@
 public final class FnNamespaceUri extends StandardFunc {
   @Override
   public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
-    final ANode node = toEmptyNode(arg(0, qc), qc);
+    final ANode node = toEmptyNode(ctxArg(0, qc), qc);
     final QNm qname = node != null ? node.qname() : null;
     return qname != null ? Uri.uri(qname.uri(), false) : Uri.EMPTY;
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnNilled.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnNilled.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnNilled.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnNilled.java	2015-07-14 10:54:40.000000000 +0000
@@ -18,7 +18,7 @@
 public final class FnNilled extends StandardFunc {
   @Override
   public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
-    final ANode node = toEmptyNode(arg(0, qc), qc);
+    final ANode node = toEmptyNode(ctxArg(0, qc), qc);
     // always false, as no schema information is given
     return node == null || node.type != NodeType.ELM ? null : Bln.FALSE;
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnNodeName.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnNodeName.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnNodeName.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnNodeName.java	2015-07-14 10:54:40.000000000 +0000
@@ -17,7 +17,7 @@
 public final class FnNodeName extends StandardFunc {
   @Override
   public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
-    final ANode node = toEmptyNode(arg(0, qc), qc);
+    final ANode node = toEmptyNode(ctxArg(0, qc), qc);
     final QNm qname = node != null ? node.qname() : null;
     return qname != null && qname.string().length != 0 ? qname : null;
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnNormalizeSpace.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnNormalizeSpace.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnNormalizeSpace.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnNormalizeSpace.java	2015-07-14 10:54:40.000000000 +0000
@@ -16,7 +16,7 @@
 public final class FnNormalizeSpace extends StandardFunc {
   @Override
   public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
-    return Str.get(Token.normalize(toEmptyToken(arg(0, qc), qc)));
+    return Str.get(Token.normalize(toEmptyToken(ctxArg(0, qc), qc)));
   }
 
   @Override
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnNumber.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnNumber.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnNumber.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnNumber.java	2015-07-14 10:54:40.000000000 +0000
@@ -17,7 +17,7 @@
 public final class FnNumber extends StandardFunc {
   @Override
   public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
-    final Item it = arg(0, qc).atomItem(qc, info);
+    final Item it = ctxArg(0, qc).atomItem(qc, info);
     if(it == null) return Dbl.NAN;
     if(it.type == AtomType.DBL) return it;
     try {
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnParseJson.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnParseJson.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnParseJson.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnParseJson.java	2015-07-14 10:54:40.000000000 +0000
@@ -19,23 +19,27 @@
  * @author Christian Gruen
  */
 public class FnParseJson extends Parse {
+  /** Function taking and returning a string. */
+  private static final FuncType STRFUNC = FuncType.get(SeqType.STR, SeqType.STR);
+
   @Override
   public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
     final Item it = exprs[0].atomItem(qc, info);
     if(it == null) return null;
-    return parse(toToken(it), qc, ii);
+    return parse(toToken(it), false, qc, ii);
   }
 
   /**
    * Parses the specified JSON string.
    * @param json json string
+   * @param xml convert to xml
    * @param qc query context
    * @param ii input info
    * @return resulting item
    * @throws QueryException query exception
    */
-  final Item parse(final byte[] json, final QueryContext qc, final InputInfo ii)
-      throws QueryException {
+  final Item parse(final byte[] json, final boolean xml, final QueryContext qc,
+      final InputInfo ii) throws QueryException {
 
     final JsonParserOptions opts = new JsonParserOptions();
     if(exprs.length > 1) {
@@ -49,19 +53,25 @@
 
     final boolean unesc = opts.get(JsonParserOptions.UNESCAPE);
     final FuncItem fb = opts.get(JsonParserOptions.FALLBACK);
-    if(fb != null) {
-      final Type type = FuncType.get(SeqType.STR, SeqType.STR);
-      if(!fb.type.instanceOf(type)) throw JSON_FUNC_OPT_X_X.get(ii, type, fb.type);
+    final FItem fallback;
+    if(fb == null) {
+      fallback = null;
+    } else {
+      try {
+        fallback = STRFUNC.cast(fb, qc, sc, ii);
+      } catch(final QueryException ex) {
+        throw JSON_OPT_X.get(ii, ex.getLocalizedMessage());
+      }
     }
 
     try {
-      opts.set(JsonOptions.FORMAT, JsonFormat.MAP);
+      opts.set(JsonOptions.FORMAT, xml ? JsonFormat.BASIC : JsonFormat.MAP);
       final JsonConverter conv = JsonConverter.get(opts);
-      if(unesc && fb != null) conv.fallback(new JsonFallback() {
+      if(unesc && fallback != null) conv.fallback(new JsonFallback() {
         @Override
-        public byte[] convert(final byte[] string) {
+        public String convert(final String string) {
           try {
-            return fb.invokeItem(qc, ii, Str.get(string)).string(ii);
+            return Token.string(fallback.invokeItem(qc, ii, Str.get(string)).string(ii));
           } catch(final QueryException ex) {
             throw new QueryRTException(ex);
           }
@@ -69,7 +79,11 @@
       });
       return conv.convert(json, null);
     } catch(final QueryRTException ex) {
-      throw ex.getCause();
+      final QueryException qe = ex.getCause();
+      final QueryError err = qe.error();
+      if(err != INVPROMOTE_X_X && err != INVPROMOTE_X_X_X) throw qe;
+      Util.debug(ex);
+      throw JSON_OPT_X.get(ii, qe.getLocalizedMessage());
     } catch(final QueryIOException ex) {
       Util.debug(ex);
       final QueryException qe = ex.getCause(info);
@@ -77,6 +91,7 @@
       final String message = ex.getLocalizedMessage();
       if(error == BXJS_PARSE_X_X_X) throw JSON_PARSE_X.get(ii, message);
       if(error == BXJS_DUPLICATE_X) throw JSON_DUPLICATE_X.get(ii, message);
+      if(error == BXJS_INVALID_X) throw JSON_OPT_X.get(ii, message);
       throw qe;
     }
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnPath.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnPath.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnPath.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnPath.java	2015-07-14 10:54:40.000000000 +0000
@@ -20,7 +20,7 @@
 public final class FnPath extends StandardFunc {
   @Override
   public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
-    ANode node = toEmptyNode(arg(0, qc), qc);
+    ANode node = toEmptyNode(ctxArg(0, qc), qc);
     if(node == null) return null;
 
     final TokenList tl = new TokenList();
@@ -35,21 +35,21 @@
         tb.add(qnm.local());
       } else if(node.type == NodeType.ELM) {
         final QNm qnm = node.qname();
-        final AxisIter ai = node.precedingSibling();
-        for(ANode fs; (fs = ai.next()) != null;) {
+        final BasicNodeIter iter = node.precedingSibling();
+        for(ANode fs; (fs = iter.next()) != null;) {
           final QNm q = fs.qname();
           if(q != null && q.eq(qnm)) i++;
         }
         tb.add("Q{").add(qnm.uri()).add('}').add(qnm.local());
         tb.add('[').add(Integer.toString(i)).add(']');
       } else if(node.type == NodeType.COM || node.type == NodeType.TXT) {
-        final AxisIter ai = node.precedingSibling();
-        for(ANode fs; (fs = ai.next()) != null;) if(fs.type == node.type) i++;
+        final BasicNodeIter iter = node.precedingSibling();
+        for(ANode fs; (fs = iter.next()) != null;) if(fs.type == node.type) i++;
         tb.addExt(node.seqType() + "[%]", i);
       } else if(node.type == NodeType.PI) {
         final QNm qnm = node.qname();
-        final AxisIter ai = node.precedingSibling();
-        for(ANode fs; (fs = ai.next()) != null;) {
+        final BasicNodeIter iter = node.precedingSibling();
+        for(ANode fs; (fs = iter.next()) != null;) {
           if(fs.type == node.type && fs.qname().eq(qnm)) i++;
         }
         tb.add(node.type.string()).add('(').add(qnm.local());
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnPut.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnPut.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnPut.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnPut.java	2015-07-14 10:54:40.000000000 +0000
@@ -36,7 +36,7 @@
     // check if all target paths are unique
     if(!updates.putPaths.add(uri)) throw UPURIDUP_X.get(info, uri);
 
-    updates.add(new Put(target.pre, target.data, uri, info), qc);
+    updates.add(new Put(target.pre(), target.data(), uri, info), qc);
     return null;
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnRandomNumberGenerator.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnRandomNumberGenerator.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnRandomNumberGenerator.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnRandomNumberGenerator.java	2015-07-14 10:54:40.000000000 +0000
@@ -2,10 +2,10 @@
 
 import org.basex.query.*;
 import org.basex.query.func.*;
+import org.basex.query.util.list.*;
 import org.basex.query.value.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.map.Map;
-import org.basex.query.value.seq.*;
 import org.basex.util.*;
 
 /**
@@ -42,7 +42,7 @@
   public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
     final long seed;
     if(exprs.length > 0) {
-      seed = exprs[0].atomItem(qc, info).hash(ii);
+      seed = toAtomItem(exprs[0], qc).hash(ii);
     } else {
       seed = qc.initDateTime().nano;
     }
@@ -74,11 +74,10 @@
     return RuntimeExpr.funcItem(new RuntimeExpr(info) {
       @Override
       public Value value(final QueryContext qc) throws QueryException {
-        final Value value = qc.get(params[0]);
-        final int sz = (int) value.size();
-        final Item[] items = new Item[sz];
-        value.writeTo(items, 0);
+        final ItemList cache = qc.get(params[0]).cache();
+        final int sz = cache.size();
 
+        final Item[] items = cache.internal();
         long s = seed;
         for(int i = sz; --i >= 1;) {
           s = next(s);
@@ -89,7 +88,7 @@
             items[j] = item;
           }
         }
-        return Seq.get(items);
+        return cache.value();
       }
     }, 1, sc, qctx);
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnRemove.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnRemove.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnRemove.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnRemove.java	2015-07-14 10:54:40.000000000 +0000
@@ -35,12 +35,10 @@
   @Override
   public Value value(final QueryContext qc) throws QueryException {
     final Value val = qc.value(exprs[0]);
-    final long p = toLong(exprs[1], qc) - 1, vs = val.size() - 1;
-    if(p < 0 || p > vs) return val;
-    if(p == 0 || p == vs) return SubSeq.get(val, p == 0 ? 1 : 0, vs);
-    final ValueBuilder vb = new ValueBuilder((int) vs);
-    for(int v = 0; v <= vs; v++) if(v != p) vb.add(val.itemAt(v));
-    return vb.value();
+    final long pos = toLong(exprs[1], qc) - 1, n = val.size();
+    if(pos < 0 || pos >= n) return val;
+    if(pos == 0 || pos + 1 == n) return val.subSeq(pos == 0 ? 1 : 0, n - 1);
+    return ((Seq) val).remove(pos);
   }
 
   @Override
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnReverse.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnReverse.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnReverse.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnReverse.java	2015-07-14 10:54:40.000000000 +0000
@@ -8,7 +8,6 @@
 import org.basex.query.value.item.*;
 import org.basex.query.value.seq.*;
 import org.basex.query.var.*;
-import org.basex.util.*;
 
 /**
  * Function implementation.
@@ -26,11 +25,9 @@
     final Iter iter = qc.iter(exprs[0]);
     final long s = iter.size();
     if(s == -1) {
-      // estimate result size (could be known in the original expression)
-      final ValueBuilder vb = new ValueBuilder(Math.max((int) exprs[0].size(), 1));
-      for(Item it; (it = iter.next()) != null;) vb.add(it);
-      Array.reverse(vb.items(), 0, (int) vb.size());
-      return vb;
+      final ValueBuilder vb = new ValueBuilder();
+      for(Item it; (it = iter.next()) != null;) vb.addFront(it);
+      return vb.value().iter();
     }
 
     // return iterator if items can be directly accessed
@@ -47,8 +44,7 @@
 
   @Override
   public Value value(final QueryContext qc) throws QueryException {
-    final Value v = exprs[0].value(qc);
-    return v.size() > 1 ? ((Seq) v).reverse() : v;
+    return exprs[0].value(qc).reverse();
   }
 
   @Override
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnRoot.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnRoot.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnRoot.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnRoot.java	2015-07-14 10:54:40.000000000 +0000
@@ -17,13 +17,8 @@
 public final class FnRoot extends StandardFunc {
   @Override
   public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
-    ANode node = toEmptyNode(arg(0, qc), qc);
-    while(node != null) {
-      final ANode p = node.parent();
-      if(p == null) break;
-      node = p;
-    }
-    return node;
+    final ANode node = toEmptyNode(ctxArg(0, qc), qc);
+    return node != null ? node.root() : null;
   }
 
   @Override
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnSort.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnSort.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnSort.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnSort.java	2015-07-14 10:54:40.000000000 +0000
@@ -42,7 +42,7 @@
       public long size() { return sz; }
       @Override
       public Value value() {
-        final ValueBuilder vb = new ValueBuilder(sz);
+        final ValueBuilder vb = new ValueBuilder();
         for(int r = 0; r < sz; r++) vb.add(get(r));
         return vb.value();
       }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnString.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnString.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnString.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnString.java	2015-07-14 10:54:40.000000000 +0000
@@ -21,7 +21,7 @@
 public final class FnString extends StandardFunc {
   @Override
   public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
-    final Item it = arg(0, qc).item(qc, info);
+    final Item it = ctxArg(0, qc).item(qc, info);
     if(it instanceof FItem) throw FISTRING_X.get(ii, it.type);
     return it == null ? Str.ZERO : it.type == AtomType.STR ? it : Str.get(it.string(ii));
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnStringLength.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnStringLength.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnStringLength.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnStringLength.java	2015-07-14 10:54:40.000000000 +0000
@@ -24,7 +24,7 @@
       if(it instanceof FItem) throw FISTRING_X.get(ii, it.type);
       s = it == null ? Token.EMPTY : it.string(ii);
     } else {
-      s = toEmptyToken(arg(0, qc), qc);
+      s = toEmptyToken(ctxArg(0, qc), qc);
     }
     return Int.get(Token.length(s));
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnSubsequence.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnSubsequence.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnSubsequence.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnSubsequence.java	2015-07-14 10:54:40.000000000 +0000
@@ -31,7 +31,7 @@
 
     // optimization: return subsequence
     final Iter iter = qc.iter(exprs[0]);
-    if(iter instanceof ValueIter) return sub((ValueIter) iter, start, len).iter();
+    if(iter instanceof ValueIter) return eval(((ValueIter) iter).value(), start, len).iter();
 
     // fast route if the size is known
     final long max = iter.size();
@@ -71,7 +71,7 @@
 
     // optimization: return subsequence
     final Iter iter = qc.iter(exprs[0]);
-    if(iter instanceof ValueIter) return sub((ValueIter) iter, start, len);
+    if(iter instanceof ValueIter) return eval(((ValueIter) iter).value(), start, len);
 
     // fast route if the size is known
     final long max = iter.size();
@@ -79,7 +79,7 @@
       final long s = Math.max(1, start) - 1;
       final long l = Math.min(max - s, len + Math.min(0, start - 1));
       if(s >= max || l <= 0) return Empty.SEQ;
-      final ValueBuilder vb = new ValueBuilder(Math.max((int) l, 1));
+      final ValueBuilder vb = new ValueBuilder();
       for(long i = 0; i < l; i++) vb.add(iter.get(s + i));
       return vb.value();
     }
@@ -124,16 +124,15 @@
 
   /**
    * Returns a subsequence.
-   * @param iter iterator
+   * @param val value
    * @param start start position
    * @param len length
    * @return sub sequence
    */
-  private static Value sub(final ValueIter iter, final long start, final long len) {
-    final Value val = iter.value();
-    final long s = Math.max(1, start) - 1;
-    final long l = Math.min(val.size() - s, len + Math.min(0, start - 1));
-    return SubSeq.get(val, s, l);
+  public static Value eval(final Value val, final long start, final long len) {
+    final long p = Math.max(0, start - 1);
+    final long k = Math.min(val.size() - p, len + Math.min(0, start - 1));
+    return k <= 0 ? Empty.SEQ : val.subSeq(p, k);
   }
 
   @Override
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnSubstring.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnSubstring.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnSubstring.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnSubstring.java	2015-07-14 10:54:40.000000000 +0000
@@ -21,7 +21,7 @@
     // normalize positions
     final byte[] str = toEmptyToken(exprs[0], qc);
 
-    final Item is = toItem(exprs[1], qc);
+    final Item is = toAtomItem(exprs[1], qc);
     int s;
     if(is instanceof Int) {
       s = (int) is.itr(info) - 1;
@@ -35,7 +35,7 @@
     int l = ascii ? str.length : length(str);
     int e = l;
     if(end) {
-      final Item ie = toItem(exprs[2], qc);
+      final Item ie = toAtomItem(exprs[2], qc);
       e = ie instanceof Int ? (int) ie.itr(info) : subPos(ie.dbl(info) + 1);
     }
     if(s < 0) {
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnTail.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnTail.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnTail.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnTail.java	2015-07-14 10:54:40.000000000 +0000
@@ -26,7 +26,7 @@
     final Iter ir = e.iter(qc);
     if(ir instanceof ValueIter) {
       final Value val = ir.value();
-      return SubSeq.get(val, 1, val.size() - 1).iter();
+      return val.size() < 2 ? Empty.ITER : val.subSeq(1, val.size() - 1).iter();
     }
     if(ir.next() == null) return Empty.ITER;
 
@@ -41,7 +41,7 @@
   @Override
   public Value value(final QueryContext qc) throws QueryException {
     final Value val = qc.value(exprs[0]);
-    return SubSeq.get(val, 1, val.size() - 1);
+    return val.size() < 2 ? Empty.SEQ : val.subSeq(1, val.size() - 1);
   }
 
   @Override
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnUnparsedTextAvailable.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnUnparsedTextAvailable.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnUnparsedTextAvailable.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnUnparsedTextAvailable.java	2015-07-14 10:54:40.000000000 +0000
@@ -13,6 +13,6 @@
 public final class FnUnparsedTextAvailable extends Parse {
   @Override
   public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
-    return unparsedText(qc, true);
+    return unparsedText(qc, true, true);
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnUnparsedText.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnUnparsedText.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnUnparsedText.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnUnparsedText.java	2015-07-14 10:54:40.000000000 +0000
@@ -13,6 +13,6 @@
 public final class FnUnparsedText extends Parse {
   @Override
   public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
-    return unparsedText(qc, false);
+    return unparsedText(qc, false, true);
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnUnparsedTextLines.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnUnparsedTextLines.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnUnparsedTextLines.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnUnparsedTextLines.java	2015-07-14 10:54:40.000000000 +0000
@@ -13,7 +13,7 @@
 public final class FnUnparsedTextLines extends Parse {
   @Override
   public Iter iter(final QueryContext qc) throws QueryException {
-    return textIter(unparsedText(qc, false).string(info));
+    return textIter(unparsedText(qc, false, true).string(info));
   }
 
   @Override
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnXmlToJson.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnXmlToJson.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/FnXmlToJson.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/FnXmlToJson.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,36 @@
+package org.basex.query.func.fn;
+
+import static org.basex.query.QueryError.*;
+
+import org.basex.build.json.*;
+import org.basex.build.json.JsonOptions.*;
+import org.basex.io.serial.*;
+import org.basex.query.*;
+import org.basex.query.value.item.*;
+import org.basex.query.value.node.*;
+import org.basex.util.*;
+import org.basex.util.options.Options.*;
+
+/**
+ * Function implementation.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Christian Gruen
+ */
+public class FnXmlToJson extends FnParseJson {
+  @Override
+  public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
+    final ANode node = toEmptyNode(exprs[0], qc);
+    final JsonSerialOptions opts = toOptions(1, null, new JsonSerialOptions(), qc);
+    if(node == null) return null;
+
+    final JsonSerialOptions jopts = new JsonSerialOptions();
+    jopts.set(JsonOptions.FORMAT, JsonFormat.BASIC);
+
+    final SerializerOptions sopts = new SerializerOptions();
+    sopts.set(SerializerOptions.METHOD, SerialMethod.JSON);
+    sopts.set(SerializerOptions.JSON, jopts);
+    sopts.set(SerializerOptions.INDENT, opts.get(JsonSerialOptions.INDENT) ? YesNo.YES : YesNo.NO);
+    return Str.get(serialize(node.iter(), sopts, INVALIDOPT_X));
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/Ids.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/Ids.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/Ids.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/Ids.java	2015-07-14 10:54:40.000000000 +0000
@@ -4,12 +4,20 @@
 import static org.basex.query.QueryText.*;
 import static org.basex.util.Token.*;
 
+import org.basex.core.locks.*;
+import org.basex.data.*;
 import org.basex.query.*;
+import org.basex.query.expr.*;
 import org.basex.query.func.*;
 import org.basex.query.iter.*;
+import org.basex.query.util.*;
+import org.basex.query.util.list.*;
+import org.basex.query.value.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.node.*;
+import org.basex.query.value.seq.*;
 import org.basex.query.value.type.*;
+import org.basex.util.hash.*;
 import org.basex.util.list.*;
 
 /**
@@ -20,62 +28,108 @@
  */
 abstract class Ids extends StandardFunc {
   /**
-   * Extracts the ids from the specified iterator.
-   * @param iter iterator
-   * @return ids
+   * Returns referenced nodes.
+   * @param qc query context
+   * @param idref follow idref
+   * @return referenced nodes
    * @throws QueryException query exception
    */
-  final byte[][] ids(final Iter iter) throws QueryException {
-    final TokenList tl = new TokenList();
-    for(Item id; (id = iter.next()) != null;) {
-      for(final byte[] i : split(normalize(toToken(id)), ' ')) tl.add(i);
+  protected BasicNodeIter ids(final QueryContext qc, final boolean idref) throws QueryException {
+    // [CG] XQuery: ID-IDREF Parsing: consider schema information
+
+    final TokenSet idSet = ids(exprs[0].atomIter(qc, info));
+    final ANode root = checkRoot(toNode(ctxArg(1, qc), qc));
+
+    final Data data = root.data();
+    if(idref || data == null) {
+      final ANodeList list = new ANodeList().check();
+      add(idSet, list, root, idref);
+      return list.iter();
+    }
+
+    // database value index can be utilized. create index iterator
+    final TokenList idList = new TokenList(idSet.size());
+    for(final byte[] id : idSet) idList.add(id);
+    final Value ids = StrSeq.get(idList);
+    final ValueAccess va = new ValueAccess(info, ids, false, null, new IndexContext(data, false));
+
+    // collect and return index results, filtered by id/idref attributes
+    final ANodeList results = new ANodeList();
+    for(final ANode attr : va.iter(qc)) {
+      if(isId(attr, idref)) results.add(attr.parent());
     }
-    return tl.finish();
+    return results.iter();
   }
 
   /**
    * Adds nodes with the specified id.
-   * @param ids ids to be found
+   * @param idSet ids to be found
+   * @param results node cache
+   * @param node current node
    * @param idref idref flag
-   * @param nc node cache
-   * @param node node
    */
-  static void add(final byte[][] ids, final NodeSeqBuilder nc, final ANode node,
-                  final boolean idref) {
-    AxisIter ai = node.attributes();
-    for(ANode at; (at = ai.next()) != null;) {
-      final byte[][] val = split(at.string(), ' ');
-      // [CG] XQuery: ID-IDREF Parsing
-      for(final byte[] id : ids) {
-        if(!eq(id, val)) continue;
-        final byte[] nm = lc(at.qname().string());
-        final boolean ii = contains(nm, ID), ir = contains(nm, IDREF);
-        if(idref ? ir : ii && !ir) nc.add(idref ? at.finish() : node);
+  private static void add(final TokenSet idSet, final ANodeList results, final ANode node,
+      final boolean idref) {
+
+    for(final ANode attr : node.attributes()) {
+      if(isId(attr, idref)) {
+        // id/idref found
+        for(final byte[] val : split(normalize(attr.string()), ' ')) {
+          // correct value: add to results
+          if(idSet.contains(val)) {
+            results.add(idref ? attr.finish() : node);
+            break;
+          }
+        }
       }
     }
-    ai = node.children();
-    for(ANode att; (att = ai.next()) != null;) add(ids, nc, att.finish(), idref);
+    for(final ANode child : node.children()) add(idSet, results, child, idref);
+  }
+
+  /**
+   * Checks if an attribute is an id/idref attribute.
+   * @param attr attribute
+   * @param idref id/idref flag
+   * @return result of check
+   */
+  private static boolean isId(final ANode attr, final boolean idref) {
+    final byte[] name = lc(attr.name());
+    return idref ? contains(name, IDREF) : contains(name, ID) && !contains(name, IDREF);
   }
 
   /**
    * Checks if the specified node has a document node as root.
    * @param node input node
-   * @return specified node
+   * @return root node
    * @throws QueryException query exception
    */
-  ANode checkRoot(final ANode node) throws QueryException {
-    if(node instanceof FNode) {
-      ANode n = node;
-      while(n.type != NodeType.DOC) {
-        n = n.parent();
-        if(n == null) throw IDDOC.get(info);
-      }
+  private ANode checkRoot(final ANode node) throws QueryException {
+    final ANode root = node.root();
+    if(root.type != NodeType.DOC) throw IDDOC.get(info);
+    return root;
+  }
+
+  /**
+   * Extracts and returns all unique ids from the iterated strings.
+   * @param iter iterator
+   * @return id set
+   * @throws QueryException query exception
+   */
+  private TokenSet ids(final Iter iter) throws QueryException {
+    final TokenSet ts = new TokenSet();
+    for(Item ids; (ids = iter.next()) != null;) {
+      for(final byte[] id : split(normalize(toToken(ids)), ' ')) ts.put(id);
     }
-    return node;
+    return ts;
   }
 
   @Override
   public final boolean has(final Flag flag) {
     return flag == Flag.CTX && exprs.length == 1 || super.has(flag);
   }
+
+  @Override
+  public final boolean accept(final ASTVisitor visitor) {
+    return (exprs.length != 1 || visitor.lock(DBLocking.CONTEXT)) && super.accept(visitor);
+  }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/Nodes.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/Nodes.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/Nodes.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/Nodes.java	2015-07-14 10:54:40.000000000 +0000
@@ -4,9 +4,9 @@
 import org.basex.query.*;
 import org.basex.query.func.*;
 import org.basex.query.iter.*;
+import org.basex.query.util.list.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.node.*;
-import org.basex.util.*;
 
 /**
  * Node functions.
@@ -23,61 +23,57 @@
    * @return outermost/innermost nodes
    * @throws QueryException exception
    */
-  Iter most(final QueryContext qc, final boolean outer) throws QueryException {
+  NodeIter most(final QueryContext qc, final boolean outer) throws QueryException {
     final Iter iter = exprs[0].iter(qc);
-    final NodeSeqBuilder nc = new NodeSeqBuilder().check();
-    for(Item it; (it = iter.next()) != null;) nc.add(toNode(it));
-    final int len = (int) nc.size();
+    final ANodeList list = new ANodeList().check();
+    for(Item it; (it = iter.next()) != null;) list.add(toNode(it));
+    final int len = list.size();
 
     // only go further if there are at least two nodes
-    if(len < 2) return nc;
+    if(len < 2) return list.iter();
 
     // after this, the iterator is sorted and duplicate free
-    if(nc.dbnodes()) {
+    final ANodeList res = new ANodeList().check();
+    if(list.dbnodes()) {
       // nodes are sorted, so ancestors always come before their descendants
       // the first/last node is thus always included in the output
-      final DBNode fst = (DBNode) nc.get(outer ? 0 : len - 1);
-      final Data data = fst.data;
-      final ANode[] nodes = nc.nodes.clone();
+      final DBNode fst = (DBNode) list.get(outer ? 0 : len - 1);
+      final Data data = fst.data();
 
       if(outer) {
         // skip the subtree of the last added node
-        nc.size(0);
-        final DBNode dummy = new DBNode(fst.data);
-        final NodeSeqBuilder src = new NodeSeqBuilder(nodes, len);
+        final DBNode dummy = new DBNode(data);
         for(int next = 0, p; next < len; next = p < 0 ? -p - 1 : p) {
-          final DBNode nd = (DBNode) nodes[next];
-          dummy.pre = nd.pre + data.size(nd.pre, data.kind(nd.pre));
-          p = src.binarySearch(dummy, next + 1, len - next - 1);
-          nc.add(nd);
+          final DBNode nd = (DBNode) list.get(next);
+          final int pre = nd.pre();
+          dummy.pre(pre + data.size(pre, data.kind(pre)));
+          p = list.binarySearch(dummy, next + 1, len - next - 1);
+          res.add(nd);
         }
       } else {
         // skip ancestors of the last added node
-        nc.nodes[0] = fst;
-        nc.size(1);
-        int before = fst.pre;
+        res.add(fst);
+        int before = fst.pre();
         for(int i = len - 1; i-- != 0;) {
-          final DBNode nd = (DBNode) nodes[i];
-          if(nd.pre + data.size(nd.pre, data.kind(nd.pre)) <= before) {
-            nc.add(nd);
-            before = nd.pre;
+          final DBNode nd = (DBNode) list.get(i);
+          final int pre = nd.pre();
+          if(pre + data.size(pre, data.kind(pre)) <= before) {
+            res.add(nd);
+            before = pre;
           }
         }
-        // nodes were added in reverse order, correct that
-        Array.reverse(nc.nodes, 0, (int) nc.size());
       }
-      return nc;
-    }
-
-    // multiple documents and/or constructed fragments
-    final NodeSeqBuilder out = new NodeSeqBuilder(new ANode[len], 0);
-    OUTER: for(int i = 0; i < len; i++) {
-      final ANode nd = nc.nodes[i];
-      final AxisIter ax = outer ? nd.ancestor() : nd.descendant();
-      for(ANode a; (a = ax.next()) != null;)
-        if(nc.indexOf(a, false) != -1) continue OUTER;
-      out.add(nd);
+    } else {
+      // multiple documents and/or constructed fragments
+      OUTER: for(int i = 0; i < len; i++) {
+        final ANode nd = list.get(i);
+        final BasicNodeIter ax = outer ? nd.ancestor() : nd.descendant();
+        for(ANode a; (a = ax.next()) != null;) {
+          if(list.indexOf(a, false) != -1) continue OUTER;
+        }
+        res.add(nd);
+      }
     }
-    return out;
+    return res.iter();
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/Parse.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/Parse.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/fn/Parse.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/fn/Parse.java	2015-07-14 10:54:40.000000000 +0000
@@ -28,18 +28,24 @@
    * Performs the unparsed-text function.
    * @param qc query context
    * @param check only check if text is available
+   * @param encoding parse encoding
    * @return content string or boolean success flag
    * @throws QueryException query exception
    */
-  Item unparsedText(final QueryContext qc, final boolean check) throws QueryException {
+  Item unparsedText(final QueryContext qc, final boolean check, final boolean encoding)
+      throws QueryException {
+
     checkCreate(qc);
-    final byte[] path = toToken(exprs[0], qc);
+    final Item it = exprs[0].atomItem(qc, info);
+    if(it == null) return check ? Bln.FALSE : null;
+
+    final byte[] path = toToken(it);
     final IO base = sc.baseIO();
 
     String enc = null;
     try {
       if(base == null) throw STBASEURI.get(info);
-      enc = toEncoding(1, ENCODING_X, qc);
+      enc = encoding ? toEncoding(1, ENCODING_X, qc) : null;
 
       final String p = string(path);
       if(p.indexOf('#') != -1) throw FRAGID_X.get(info, p);
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/ft/FtCount.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/ft/FtCount.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/ft/FtCount.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/ft/FtCount.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,8 +1,8 @@
 package org.basex.query.func.ft;
 
-import org.basex.data.*;
 import org.basex.query.*;
 import org.basex.query.iter.*;
+import org.basex.query.util.ft.*;
 import org.basex.query.value.item.*;
 import org.basex.util.*;
 
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/ft/FtMark.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/ft/FtMark.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/ft/FtMark.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/ft/FtMark.java	2015-07-14 10:54:40.000000000 +0000
@@ -7,6 +7,7 @@
 import org.basex.query.func.*;
 import org.basex.query.iter.*;
 import org.basex.query.util.*;
+import org.basex.query.util.ft.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.seq.*;
 import org.basex.query.value.type.*;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/FuncLit.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/FuncLit.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/FuncLit.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/FuncLit.java	2015-07-14 10:54:40.000000000 +0000
@@ -105,7 +105,7 @@
 
   @Override
   public boolean has(final Flag flag) {
-    return flag == Flag.CTX || flag == Flag.FCS;
+    return flag == Flag.CTX || flag == Flag.POS;
   }
 
   @Override
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/FuncOptions.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/FuncOptions.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/FuncOptions.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/FuncOptions.java	2015-07-14 10:54:40.000000000 +0000
@@ -25,7 +25,7 @@
   /** QName. */
   public static final QNm Q_SPARAM = QNm.get(SERIALIZATION_PARAMETERS, OUTPUT_URI);
   /** Value. */
-  private static final String VALUE = "value";
+  private static final byte[] VALUE = token("value");
 
   /** Root element. */
   private final QNm root;
@@ -99,7 +99,8 @@
           } else if(!test.eq(item)) {
             throw ELMMAP_X_X_X.get(info, root.prefixId(XML), item.type, item);
           }
-          options.parse(tb.add(optString((ANode) item)).toString());
+          final String opts = optString((ANode) item, error);
+          options.parse(tb.add(opts).toString());
         }
       } catch(final BaseXException ex) {
         throw error.get(info, ex);
@@ -111,26 +112,42 @@
   /**
    * Builds a string representation of the specified node.
    * @param node node
+   * @param error raise error code
    * @return string
    * @throws QueryException query exception
    */
-  private String optString(final ANode node) throws QueryException {
+  private String optString(final ANode node, final QueryError error) throws QueryException {
+    final ANode n = node.attributes().next();
+    if(n != null) throw error.get(info, Util.info("Invalid attribute: '%'", n.name()));
+
     final TokenBuilder tb = new TokenBuilder();
     // interpret options
     for(final ANode child : node.children()) {
       if(child.type != NodeType.ELM) continue;
+
       // ignore elements in other namespace
       final QNm qn = child.qname();
-      if(!eq(qn.uri(), root.uri())) continue;
+      if(!eq(qn.uri(), root.uri())) {
+        if(qn.uri().length == 0)
+          throw error.get(info, Util.info("Element has no namespace: '%'", qn));
+        continue;
+      }
       // retrieve key from element name and value from "value" attribute or text node
-      byte[] v;
+      byte[] v = null;
       if(hasElements(child)) {
-        v = token(optString(child));
+        v = token(optString(child, error));
       } else {
-        v = child.attribute(VALUE);
+        for(final ANode attr : child.attributes()) {
+          if(eq(attr.name(), VALUE)) {
+            v = attr.string();
+          } else {
+            // Conflicts with QT3TS, Serialization-json-34 etc.
+            //throw error.get(info, Util.info("Invalid attribute: '%'", attr.name()));
+          }
+        }
         if(v == null) v = child.string();
       }
-      tb.add(string(qn.local())).add('=').add(string(v).replace(",", ",,")).add(',');
+      tb.add(string(qn.local())).add('=').add(string(v).trim().replace(",", ",,")).add(',');
     }
     return tb.toString();
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/Function.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/Function.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/Function.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/Function.java	2015-07-14 10:54:40.000000000 +0000
@@ -57,7 +57,7 @@
 /**
  * Definitions of all built-in XQuery functions.
  * New namespace mappings for function prefixes and URIs must be added to the static initializer of
- * the {@code NSGlobal} class.
+ * the {@link NSGlobal} class.
  *
  * @author BaseX Team 2005-15, BSD License
  * @author Christian Gruen
@@ -204,7 +204,7 @@
   FUNCTION_ARITY(FnFunctionArity.class, "function-arity(function)", arg(FUN_O), ITR),
   /** XQuery function. */
   FUNCTION_LOOKUP(FnFunctionLookup.class, "function-lookup(name,arity)",
-      arg(QNM, ITR), FUN_OZ, flag(CTX, FCS, NDT, HOF)),
+      arg(QNM, ITR), FUN_OZ, flag(CTX, Flag.POS, NDT, HOF)),
   /** XQuery function. */
   FUNCTION_NAME(FnFunctionName.class, "function-name(function)", arg(FUN_O), QNM_ZO),
   /** XQuery function. */
@@ -243,7 +243,7 @@
   /** XQuery function. */
   LANG(FnLang.class, "lang(ids[,node])", arg(STR_ZO, NOD), BLN),
   /** XQuery function. */
-  LAST(FnLast.class, "last()", arg(), ITR, flag(FCS, CTX)),
+  LAST(FnLast.class, "last()", arg(), ITR, flag(Flag.POS, CTX)),
   /** XQuery function. */
   LOCAL_NAME(FnLocalName.class, "local-name([node])", arg(NOD_ZO), STR),
   /** XQuery function. */
@@ -303,7 +303,11 @@
   /** XQuery function. */
   PARSE_IETF_DATE(FnParseIetfDate.class, "parse-ietf-date(string)", arg(STR_ZO), DTM_ZO),
   /** XQuery function. */
-  PARSE_JSON(FnParseJson.class, "parse-json(string[,options])", arg(STR_ZO, ITEM), DTM_ZO),
+  JSON_TO_XML(FnJsonToXml.class, "json-to-xml(string[,options])", arg(STR_ZO, MAP_O), NOD_ZO),
+  /** XQuery function. */
+  XML_TO_JSON(FnXmlToJson.class, "xml-to-json(node[,options])", arg(NOD_ZO, MAP_O), STR_ZO),
+  /** XQuery function. */
+  PARSE_JSON(FnParseJson.class, "parse-json(string[,options])", arg(STR_ZO, ITEM), ITEM_ZO),
   /** XQuery function. */
   PARSE_XML(FnParseXml.class, "parse-xml(string)", arg(STR_ZO), DOC_O, flag(CNS)),
   /** XQuery function. */
@@ -311,7 +315,7 @@
   /** XQuery function. */
   PATH(FnPath.class, "path([node])", arg(NOD_ZO), STR_ZO),
   /** XQuery function. */
-  POSITION(FnPosition.class, "position()", arg(), ITR, flag(FCS, CTX)),
+  POSITION(FnPosition.class, "position()", arg(), ITR, flag(Flag.POS, CTX)),
   /** XQuery function. */
   PREFIX_FROM_QNAME(FnPrefixFromQName.class, "prefix-from-QName(qname)", arg(QNM_ZO), NCN_ZO),
   /** XQuery function. */
@@ -464,11 +468,11 @@
   /** XQuery function. */
   _ARRAY_HEAD(ArrayHead.class, "head(array)", arg(ARRAY_O), ITEM_ZM, ARRAY_URI),
   /** XQuery function. */
-  _ARRAY_TAIL(ArrayTail.class, "tail(array)", arg(ARRAY_O), ITEM_ZM, ARRAY_URI),
+  _ARRAY_TAIL(ArrayTail.class, "tail(array)", arg(ARRAY_O), ARRAY_O, ARRAY_URI),
   /** XQuery function. */
-  _ARRAY_REVERSE(ArrayReverse.class, "reverse(array)", arg(ARRAY_O), ITEM_ZM, ARRAY_URI),
+  _ARRAY_REVERSE(ArrayReverse.class, "reverse(array)", arg(ARRAY_O), ARRAY_O, ARRAY_URI),
   /** XQuery function. */
-  _ARRAY_JOIN(ArrayJoin.class, "join(array)", arg(ARRAY_ZM), ITEM_ZM, ARRAY_URI),
+  _ARRAY_JOIN(ArrayJoin.class, "join(array)", arg(ARRAY_ZM), ARRAY_O, ARRAY_URI),
   /** XQuery function. */
   _ARRAY_FLATTEN(ArrayFlatten.class, "flatten(item()*)", arg(ITEM_ZM), ITEM_ZM, ARRAY_URI),
   /** XQuery function. */
@@ -545,7 +549,8 @@
   /** XQuery function. */
   _ADMIN_LOGS(AdminLogs.class, "logs([date[,merge]])", arg(STR, BLN), ELM_ZM, flag(NDT), ADMIN_URI),
   /** XQuery function. */
-  _ADMIN_WRITE_LOG(AdminWriteLog.class, "write-log(string)", arg(STR), EMP, flag(NDT), ADMIN_URI),
+  _ADMIN_WRITE_LOG(AdminWriteLog.class, "write-log(message[,type])",
+      arg(STR, STR), EMP, flag(NDT), ADMIN_URI),
   /** XQuery function. */
   _ADMIN_DELETE_LOGS(AdminDeleteLogs.class, "delete-logs(date)",
       arg(STR), EMP, flag(NDT), ADMIN_URI),
@@ -556,6 +561,9 @@
   _ARCHIVE_CREATE(ArchiveCreate.class, "create(entries,contents[,options])",
       arg(ITEM_ZM, ITEM_ZM, ITEM), B64, ARCHIVE_URI),
   /** XQuery function. */
+  _ARCHIVE_CREATE_FROM(ArchiveCreateFrom.class, "create-from(path[,options[,entries]])",
+      arg(STR, ITEM, ITEM_ZM), EMP, ARCHIVE_URI),
+  /** XQuery function. */
   _ARCHIVE_ENTRIES(ArchiveEntries.class, "entries(archive)", arg(B64), ELM_ZM, ARCHIVE_URI),
   /** XQuery function. */
   _ARCHIVE_EXTRACT_TEXT(ArchiveExtractText.class, "extract-text(archive[,entries[,encoding]])",
@@ -564,6 +572,9 @@
   _ARCHIVE_EXTRACT_BINARY(ArchiveExtractBinary.class, "extract-binary(archive[,entries])",
       arg(B64, ITEM_ZM), B64_ZM, ARCHIVE_URI),
   /** XQuery function. */
+  _ARCHIVE_EXTRACT_TO(ArchiveExtractTo.class, "extract-to(path,archive[,entries])",
+      arg(STR, B64, ITEM_ZM), EMP, ARCHIVE_URI),
+  /** XQuery function. */
   _ARCHIVE_UPDATE(ArchiveUpdate.class, "update(archive,entries,contents)",
       arg(B64, ITEM_ZM, ITEM_ZM), B64, ARCHIVE_URI),
   /** XQuery function. */
@@ -571,8 +582,8 @@
       arg(B64, ITEM_ZM), B64, ARCHIVE_URI),
   /** XQuery function. */
   _ARCHIVE_OPTIONS(ArchiveOptions.class, "options(archive)", arg(B64), ELM, ARCHIVE_URI),
-  /** XQuery function. */
-  _ARCHIVE_WRITE(ArchiveWrite.class, "write(path,archive[,entries])",
+  /** XQuery function (deprecated). */
+  @Deprecated _ARCHIVE_WRITE(ArchiveWrite.class, "write(path,archive[,entries])",
       arg(STR, B64, ITEM_ZM), EMP, ARCHIVE_URI),
 
   /* BaseX Module. */
@@ -786,10 +797,10 @@
   /** XQuery function. */
   _DB_NODE_PRE(DbNodePre.class, "node-pre(nodes)", arg(NOD_ZM), ITR_ZM, DB_URI),
   /** XQuery function. */
-  _DB_EVENT(DbEvent.class, "event(name,query)", arg(STR, ITEM_ZM), EMP, flag(NDT), DB_URI),
-  /** XQuery function. */
   _DB_OUTPUT(DbOutput.class, "output(result)", arg(ITEM_ZM), EMP, flag(UPD, NDT), DB_URI),
   /** XQuery function. */
+  _DB_OUTPUT_CACHE(DbOutputCache.class, "output-cache()", arg(), ITEM_ZO, flag(NDT), DB_URI),
+  /** XQuery function. */
   _DB_ADD(DbAdd.class, "add(database,input[,path[,options]])",
       arg(STR, NOD, STR, ITEM), EMP, flag(UPD, NDT), DB_URI),
   /** XQuery function. */
@@ -864,6 +875,8 @@
   /** XQuery function. */
   _FILE_IS_DIR(FileIsDir.class, "is-dir(path)", arg(STR), BLN, flag(NDT), FILE_URI),
   /** XQuery function. */
+  _FILE_IS_ABSOLUTE(FileIsAbsolute.class, "is-absolute(path)", arg(STR), BLN, flag(NDT), FILE_URI),
+  /** XQuery function. */
   _FILE_IS_FILE(FileIsFile.class, "is-file(path)", arg(STR), BLN, flag(NDT), FILE_URI),
   /** XQuery function. */
   _FILE_LAST_MODIFIED(FileLastModified.class, "last-modified(path)",
@@ -874,8 +887,8 @@
   _FILE_PATH_TO_NATIVE(FilePathToNative.class, "path-to-native(path)",
       arg(STR), STR, flag(NDT), FILE_URI),
   /** XQuery function. */
-  _FILE_RESOLVE_PATH(FileResolvePath.class, "resolve-path(path)",
-      arg(STR), STR, flag(NDT), FILE_URI),
+  _FILE_RESOLVE_PATH(FileResolvePath.class, "resolve-path(path[,base])",
+      arg(STR, STR), STR, flag(NDT), FILE_URI),
   /** XQuery function. */
   _FILE_LIST(FileList.class, "list(path[,recursive[,pattern]])",
       arg(STR, BLN, STR), STR_ZM, flag(NDT), FILE_URI),
@@ -1202,6 +1215,12 @@
   /** XQuery function. */
   _VALIDATE_DTD_INFO(ValidateDtdInfo.class, "dtd-info(input[,schema])",
       arg(ITEM, ITEM), STR_ZM, flag(NDT), VALIDATE_URI),
+  /** XQuery function. */
+  _VALIDATE_RNG(ValidateRng.class, "rng(input,schema[,compact])",
+      arg(ITEM, ITEM, BLN), STR_ZM, flag(NDT), VALIDATE_URI),
+  /** XQuery function. */
+  _VALIDATE_RNG_INFO(ValidateRngInfo.class, "rng-info(input,schema[,compact])",
+      arg(ITEM, ITEM, BLN), STR_ZM, flag(NDT), VALIDATE_URI),
 
   /* Web Module. */
 
@@ -1214,6 +1233,10 @@
   /** XQuery function. */
   _WEB_RESPONSE_HEADER(WebResponseHeader.class, "response-header([headers[,output]])",
       arg(MAP_O, MAP_O), ELM, WEB_URI),
+  /** XQuery function. */
+  _WEB_ENCODE_URL(WebEncodeUrl.class, "encode-url(string)", arg(STR), STR, WEB_URI),
+  /** XQuery function. */
+  _WEB_DECODE_URL(WebDecodeUrl.class, "decode-url(string)", arg(STR), STR, WEB_URI),
 
   /* XQuery Module. */
 
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/Functions.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/Functions.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/Functions.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/Functions.java	2015-07-14 10:54:40.000000000 +0000
@@ -187,7 +187,7 @@
         qc.updating();
         anns.add(new Ann(ii, Annotation.UPDATING));
       }
-      if(!sf.has(Flag.CTX) && !sf.has(Flag.FCS)) return closureOrFItem(
+      if(!sf.has(Flag.CTX) && !sf.has(Flag.POS)) return closureOrFItem(
           anns, name, args, fn.type(arity, anns), sf, scp, sc, ii, runtime, upd);
 
       return new FuncLit(anns, name, args, sf, ft, scp, sc, ii);
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/hof/HofSortWith.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/hof/HofSortWith.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/hof/HofSortWith.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/hof/HofSortWith.java	2015-07-14 10:54:40.000000000 +0000
@@ -4,6 +4,7 @@
 
 import org.basex.query.*;
 import org.basex.query.iter.*;
+import org.basex.query.util.list.*;
 import org.basex.query.value.*;
 import org.basex.query.value.item.*;
 
@@ -24,12 +25,12 @@
     final Value v = exprs[0].value(qc);
     final Comparator<Item> cmp = getComp(1, qc);
     if(v.size() < 2) return v;
-    final ValueBuilder vb = v.cache();
+    final ItemList items = v.cache();
     try {
-      Arrays.sort(vb.items(), 0, (int) vb.size(), cmp);
+      Arrays.sort(items.internal(), 0, items.size(), cmp);
     } catch(final QueryRTException ex) {
       throw ex.getCause();
     }
-    return vb.value();
+    return items.value();
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/hof/HofTakeWhile.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/hof/HofTakeWhile.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/hof/HofTakeWhile.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/hof/HofTakeWhile.java	2015-07-14 10:54:40.000000000 +0000
@@ -24,7 +24,7 @@
       @Override
       public Item next() throws QueryException {
         final Item it = in.next();
-        if(it != null && pred.invokeValue(qc, info, it).ebv(qc, info).bool(info)) return it;
+        if(it != null && toBoolean(pred.invokeValue(qc, info, it), qc)) return it;
         return null;
       }
     };
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/hof/HofTopKBy.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/hof/HofTopKBy.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/hof/HofTopKBy.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/hof/HofTopKBy.java	2015-07-14 10:54:40.000000000 +0000
@@ -48,8 +48,8 @@
       }
     } catch(final QueryRTException ex) { throw ex.getCause(); }
 
-    final Item[] arr = new Item[heap.size()];
-    for(int i = arr.length; --i >= 0;) arr[i] = heap.removeMin();
-    return Seq.get(arr);
+    final ValueBuilder vb = new ValueBuilder();
+    while(!heap.isEmpty()) vb.addFront(heap.removeMin());
+    return vb.value();
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/hof/HofTopKWith.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/hof/HofTopKWith.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/hof/HofTopKWith.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/hof/HofTopKWith.java	2015-07-14 10:54:40.000000000 +0000
@@ -37,8 +37,8 @@
       }
     } catch(final QueryRTException ex) { throw ex.getCause(); }
 
-    final Item[] arr = new Item[heap.size()];
-    for(int i = arr.length; --i >= 0;) arr[i] = heap.removeMin();
-    return Seq.get(arr);
+    final ValueBuilder vb = new ValueBuilder();
+    while(!heap.isEmpty()) vb.addFront(heap.removeMin());
+    return vb.value();
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/http/HttpSendRequest.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/http/HttpSendRequest.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/http/HttpSendRequest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/http/HttpSendRequest.java	2015-07-14 10:54:40.000000000 +0000
@@ -3,6 +3,7 @@
 import org.basex.query.*;
 import org.basex.query.func.*;
 import org.basex.query.iter.*;
+import org.basex.query.util.list.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.node.*;
 import org.basex.util.http.*;
@@ -15,7 +16,7 @@
  */
 public final class HttpSendRequest extends StandardFunc {
   @Override
-  public ValueIter iter(final QueryContext qc) throws QueryException {
+  public Iter iter(final QueryContext qc) throws QueryException {
     checkCreate(qc);
 
     // get request node
@@ -24,13 +25,14 @@
     // get HTTP URI
     final byte[] href = exprs.length >= 2 ? toEmptyToken(exprs[1], qc) : null;
     // get parameter $bodies
-    ValueBuilder cache = null;
+    Iter iter = null;
     if(exprs.length == 3) {
       final Iter bodies = exprs[2].iter(qc);
-      cache = new ValueBuilder();
+      final ItemList cache = new ItemList();
       for(Item body; (body = bodies.next()) != null;) cache.add(body);
+      iter = cache.iter();
     }
     // send HTTP request
-    return new HttpClient(info, qc.context.options).sendRequest(href, request, cache);
+    return new HttpClient(info, qc.context.options).sendRequest(href, request, iter);
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/index/IndexFn.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/index/IndexFn.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/index/IndexFn.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/index/IndexFn.java	2015-07-14 10:54:40.000000000 +0000
@@ -8,6 +8,7 @@
 import org.basex.data.*;
 import org.basex.index.*;
 import org.basex.index.query.*;
+import org.basex.index.value.*;
 import org.basex.query.*;
 import org.basex.query.func.*;
 import org.basex.query.iter.*;
@@ -42,7 +43,7 @@
   public static Iter entries(final Data data, final IndexEntries entries, final StandardFunc call)
       throws QueryException {
 
-    final Index index;
+    final ValueIndex index;
     final boolean avl;
     final IndexType it = entries.type();
     if(it == IndexType.TEXT) {
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/inspect/InspectFunctions.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/inspect/InspectFunctions.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/inspect/InspectFunctions.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/inspect/InspectFunctions.java	2015-07-14 10:54:40.000000000 +0000
@@ -11,6 +11,7 @@
 import org.basex.query.expr.*;
 import org.basex.query.func.*;
 import org.basex.query.iter.*;
+import org.basex.query.value.*;
 import org.basex.query.value.item.*;
 import org.basex.query.var.*;
 import org.basex.util.*;
@@ -24,6 +25,11 @@
 public final class InspectFunctions extends StandardFunc {
   @Override
   public Iter iter(final QueryContext qc) throws QueryException {
+    return value(qc).iter();
+  }
+
+  @Override
+  public Value value(final QueryContext qc) throws QueryException {
     checkCreate(qc);
     // about to be updated in a future version
     final ArrayList<StaticFunc> old = new ArrayList<>();
@@ -45,7 +51,7 @@
       final FuncItem fi = Functions.getUser(sf, qc, sf.sc, info);
       if(sc.mixUpdates || !fi.annotations().contains(Annotation.UPDATING)) vb.add(fi);
     }
-    return vb;
+    return vb.value();
   }
 
   @Override
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/inspect/Inspect.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/inspect/Inspect.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/inspect/Inspect.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/inspect/Inspect.java	2015-07-14 10:54:40.000000000 +0000
@@ -6,6 +6,9 @@
 
 import java.io.*;
 
+import org.basex.build.*;
+import org.basex.build.xml.*;
+import org.basex.core.*;
 import org.basex.io.*;
 import org.basex.query.*;
 import org.basex.query.util.*;
@@ -90,8 +93,14 @@
 
     for(final Ann ann : anns) {
       final FElem annotation = elem("annotation", parent);
-      annotation.add("name", ann.sig.id());
-      if(uri) annotation.add("uri", ann.sig.uri);
+      if(ann.sig != null) {
+        annotation.add("name", ann.sig.id());
+        if(uri) annotation.add("uri", ann.sig.uri);
+      } else {
+        annotation.add("name", ann.name.string());
+        if(uri) annotation.add("uri", ann.name.uri());
+      }
+
       for(final Item it : ann.args) {
         final FElem literal = elem("literal", annotation);
         literal.add("type", it.type.toString()).add(it.string(null));
@@ -121,9 +130,10 @@
    * @param elem element
    */
   public static void add(final byte[] value, final FElem elem) {
+
     try {
-      final ANode node = new DBNode(new IOContent(value));
-      for(final ANode n : node.children()) elem.add(n.copy());
+      final Parser parser = new XMLParser(new IOContent(value), MainOptions.get(), true);
+      for(final ANode node : new DBNode(parser).children()) elem.add(node.copy());
     } catch(final IOException ex) {
       // fallback: add string representation
       Util.debug(ex);
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/inspect/XQDoc.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/inspect/XQDoc.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/inspect/XQDoc.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/inspect/XQDoc.java	2015-07-14 10:54:40.000000000 +0000
@@ -45,7 +45,7 @@
     final QueryParser qp = parseQuery(io);
     final FElem xqdoc = new FElem(PREFIX, PREFIX, URI).declareNS();
     final FElem control = elem("control", xqdoc);
-    elem("date", control).add(qc.initDateTime().dtm.string(info));
+    elem("date", control).add(qc.initDateTime().datm.string(info));
     elem("version", control).add("1.1");
 
     final String type = module instanceof LibraryModule ? "library" : "main";
@@ -157,7 +157,8 @@
     if(!anns.isEmpty()) annotation(anns, elem("annotations", parent), false);
     final int al = anns.size();
     for(int a = 0; a < al; a++) {
-      final byte[] uri = anns.get(a).sig.uri;
+      final Ann ann = anns.get(a);
+      final byte[] uri = ann.sig != null ? ann.sig.uri : ann.name.uri();
       if(uri.length > 0) nsCache.put(NSGlobal.prefix(uri), uri);
     }
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/JavaMapping.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/JavaMapping.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/JavaMapping.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/JavaMapping.java	2015-07-14 10:54:40.000000000 +0000
@@ -155,7 +155,7 @@
     }
     // any other array (also nested ones)
     final Object[] objs = (Object[]) obj;
-    final ValueBuilder vb = new ValueBuilder(objs.length);
+    final ValueBuilder vb = new ValueBuilder();
     for(final Object o : objs) vb.add(toValue(o, qc, sc));
     return vb.value();
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/JavaModuleFunc.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/JavaModuleFunc.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/JavaModuleFunc.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/JavaModuleFunc.java	2015-07-14 10:54:40.000000000 +0000
@@ -120,7 +120,7 @@
   @Override
   public boolean has(final Flag f) {
     return f == Flag.NDT && method.getAnnotation(Deterministic.class) == null ||
-      (f == Flag.CTX || f == Flag.FCS) &&
+      (f == Flag.CTX || f == Flag.POS) &&
       method.getAnnotation(FocusDependent.class) == null ||
       super.has(f);
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/json/JsonFn.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/json/JsonFn.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/json/JsonFn.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/json/JsonFn.java	2015-07-14 10:54:40.000000000 +0000
@@ -6,7 +6,7 @@
 import org.basex.query.value.item.*;
 
 /**
- * Functions for parsing and serializing JSON objects.
+ * Function implementation.
  *
  * @author BaseX Team 2005-15, BSD License
  * @author Christian Gruen
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/json/JsonParse.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/json/JsonParse.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/json/JsonParse.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/json/JsonParse.java	2015-07-14 10:54:40.000000000 +0000
@@ -7,7 +7,7 @@
 import org.basex.util.*;
 
 /**
- * Functions for parsing and serializing JSON objects.
+ * Function implementation.
  *
  * @author BaseX Team 2005-15, BSD License
  * @author Christian Gruen
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/json/JsonSerialize.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/json/JsonSerialize.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/json/JsonSerialize.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/json/JsonSerialize.java	2015-07-14 10:54:40.000000000 +0000
@@ -10,7 +10,7 @@
 import org.basex.util.*;
 
 /**
- * Functions for parsing and serializing JSON objects.
+ * Function implementation.
  *
  * @author BaseX Team 2005-15, BSD License
  * @author Christian Gruen
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/map/MapForEach.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/map/MapForEach.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/map/MapForEach.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/map/MapForEach.java	2015-07-14 10:54:40.000000000 +0000
@@ -14,11 +14,11 @@
 public final class MapForEach extends StandardFunc {
   @Override
   public Iter iter(final QueryContext qc) throws QueryException {
-    return toMap(exprs[0], qc).apply(checkArity(exprs[1], 2, qc), qc, info);
+    return value(qc).iter();
   }
 
   @Override
   public Value value(final QueryContext qc) throws QueryException {
-    return iter(qc).value();
+    return toMap(exprs[0], qc).apply(checkArity(exprs[1], 2, qc), qc, info);
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/repo/RepoList.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/repo/RepoList.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/repo/RepoList.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/repo/RepoList.java	2015-07-14 10:54:40.000000000 +0000
@@ -3,6 +3,7 @@
 import org.basex.io.*;
 import org.basex.query.*;
 import org.basex.query.iter.*;
+import org.basex.query.util.list.*;
 import org.basex.query.util.pkg.*;
 import org.basex.query.util.pkg.Package;
 import org.basex.query.value.node.*;
@@ -24,8 +25,8 @@
   private static final String VERSION = "version";
 
   @Override
-  public Iter iter(final QueryContext qc) throws QueryException {
-    final NodeSeqBuilder cache = new NodeSeqBuilder();
+  public BasicNodeIter iter(final QueryContext qc) throws QueryException {
+    final ANodeList cache = new ANodeList();
     final Repo repo = qc.context.repo.reset();
     for(final byte[] p : repo.pkgDict()) {
       if(p == null) continue;
@@ -45,6 +46,6 @@
         cache.add(elem);
       }
     }
-    return cache;
+    return cache.iter();
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/sql/SqlExecutePrepared.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/sql/SqlExecutePrepared.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/sql/SqlExecutePrepared.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/sql/SqlExecutePrepared.java	2015-07-14 10:54:40.000000000 +0000
@@ -46,6 +46,8 @@
 
   /** Attribute "type" of <sql:parameter/>. */
   private static final byte[] TYPE = token("type");
+  /** Attribute "null" of <sql:parameter/>. */
+  private static final byte[] NULL = token("null");
 
   @Override
   public Iter iter(final QueryContext qc) throws QueryException {
@@ -78,7 +80,7 @@
    * @return number of parameters
    */
   private static long countParams(final ANode params) {
-    final AxisIter ch = params.children();
+    final BasicNodeIter ch = params.children();
     long n = ch.size();
     if(n == -1) do ++n;
     while(ch.next() != null);
@@ -91,14 +93,14 @@
    * @param stmt prepared statement
    * @throws QueryException query exception
    */
-  private void setParameters(final AxisMoreIter params, final PreparedStatement stmt)
+  private void setParameters(final BasicNodeIter params, final PreparedStatement stmt)
       throws QueryException {
 
     int i = 0;
     for(ANode next; (next = params.next()) != null;) {
       // Check name
       if(!next.qname().eq(Q_PARAMETER)) throw INVALIDOPTION_X.get(info, next.qname().local());
-      final AxisIter attrs = next.attributes();
+      final BasicNodeIter attrs = next.attributes();
       byte[] paramType = null;
       boolean isNull = false;
       for(ANode attr; (attr = attrs.next()) != null;) {
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/StandardFunc.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/StandardFunc.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/StandardFunc.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/StandardFunc.java	2015-07-14 10:54:40.000000000 +0000
@@ -20,6 +20,7 @@
 import org.basex.query.iter.*;
 import org.basex.query.util.*;
 import org.basex.query.util.collation.*;
+import org.basex.query.util.list.*;
 import org.basex.query.value.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.map.Map;
@@ -99,7 +100,7 @@
     final int es = exprs.length;
     final Expr[] arg = new Expr[es];
     for(int e = 0; e < es; e++) arg[e] = exprs[e].copy(qc, scp, vs);
-    return sig.get(sc, info, arg);
+    return copyType(sig.get(sc, info, arg));
   }
 
   /**
@@ -163,7 +164,7 @@
    * @return expression
    * @throws QueryException query exception
    */
-  protected Expr arg(final int index, final QueryContext qc) throws QueryException {
+  protected Expr ctxArg(final int index, final QueryContext qc) throws QueryException {
     return exprs.length == index ? ctxValue(qc) : exprs[index];
   }
 
@@ -373,17 +374,17 @@
   /**
    * Caches and materializes all items of the specified iterator.
    * @param iter iterator
-   * @param vb value builder
+   * @param cache item list
    * @param qc query context
    * @throws QueryException query exception
    */
-  protected final void cache(final Iter iter, final ValueBuilder vb, final QueryContext qc)
+  protected final void cache(final Iter iter, final ItemList cache, final QueryContext qc)
       throws QueryException {
 
     for(Item it; (it = iter.next()) != null;) {
       qc.checkStop();
       if(it instanceof FItem) throw FISTRING_X.get(info, it.type);
-      vb.add(it.materialize(info));
+      cache.add(it.materialize(info));
     }
   }
 
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/StaticFuncCall.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/StaticFuncCall.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/StaticFuncCall.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/StaticFuncCall.java	2015-07-14 10:54:40.000000000 +0000
@@ -119,8 +119,8 @@
   public boolean has(final Flag flag) {
     // check arguments, which will be evaluated before running the function code
     if(super.has(flag)) return true;
-    // function code: position or context references will have no effect on calling code
-    if(flag == Flag.FCS || flag == Flag.CTX) return false;
+    // function code: position or context references of expression body have no effect
+    if(flag == Flag.POS || flag == Flag.CTX) return false;
     // pass on check to function code
     return func == null || (flag == Flag.UPD && !sc.mixUpdates ? func.updating : func.has(flag));
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/stream/StreamIsStreamable.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/stream/StreamIsStreamable.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/stream/StreamIsStreamable.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/stream/StreamIsStreamable.java	2015-07-14 10:54:40.000000000 +0000
@@ -14,7 +14,7 @@
 public final class StreamIsStreamable extends StandardFunc {
   @Override
   public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
-    final Item it = toItem(exprs[0], qc);
+    final Item it = toAtomItem(exprs[0], qc);
     return Bln.get(it instanceof StrStream || it instanceof B64Stream);
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/unit/UnitAssertEquals.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/unit/UnitAssertEquals.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/unit/UnitAssertEquals.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/unit/UnitAssertEquals.java	2015-07-14 10:54:40.000000000 +0000
@@ -17,7 +17,7 @@
 public final class UnitAssertEquals extends UnitFn {
   @Override
   public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
-    final Item it = exprs.length < 3 ? null : toItem(exprs[2], qc);
+    final Item it = exprs.length < 3 ? null : toNodeOrAtomItem(exprs[2], qc);
     final Iter iter1 = qc.iter(exprs[0]), iter2 = qc.iter(exprs[1]);
     final Compare comp = new Compare(info);
     Item it1, it2;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/unit/UnitAssert.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/unit/UnitAssert.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/unit/UnitAssert.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/unit/UnitAssert.java	2015-07-14 10:54:40.000000000 +0000
@@ -13,8 +13,9 @@
 public final class UnitAssert extends UnitFn {
   @Override
   public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
-    final Item it = exprs.length < 2 ? null : toItem(exprs[1], qc);
-    if(exprs[0].ebv(qc, info).bool(info)) return null;
+    final boolean ok = exprs[0].ebv(qc, info).bool(info);
+    final Item it = exprs.length < 2 ? null : toNodeOrAtomItem(exprs[1], qc);
+    if(ok) return null;
     throw error(it);
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/unit/UnitFail.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/unit/UnitFail.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/unit/UnitFail.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/unit/UnitFail.java	2015-07-14 10:54:40.000000000 +0000
@@ -12,6 +12,6 @@
 public final class UnitFail extends UnitFn {
   @Override
   public Iter iter(final QueryContext qc) throws QueryException {
-    throw error(exprs.length < 1 ? null : toItem(exprs[0], qc));
+    throw error(exprs.length < 1 ? null : toNodeOrAtomItem(exprs[0], qc));
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/unit/Unit.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/unit/Unit.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/unit/Unit.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/unit/Unit.java	2015-07-14 10:54:40.000000000 +0000
@@ -87,7 +87,7 @@
         // find Unit annotations
         final AnnList anns = sf.anns;
         boolean xq = false;
-        for(final Ann ann : anns) xq |= eq(ann.sig.uri, QueryText.UNIT_URI);
+        for(final Ann ann : anns) xq |= ann.sig != null && eq(ann.sig.uri, QueryText.UNIT_URI);
         if(!xq) continue;
 
         // Unit function:
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/user/UserAlter.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/user/UserAlter.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/user/UserAlter.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/user/UserAlter.java	2015-07-14 10:54:40.000000000 +0000
@@ -41,14 +41,14 @@
      */
     private Alter(final User user, final String newname, final QueryContext qc,
         final InputInfo info) {
-      super(UpdateType.USERALTER, user, null, qc, info);
+      super(UpdateType.USERALTER, user, "", qc, info);
       this.newname = newname;
     }
 
     @Override
     public void apply() {
       final User old = users.get(newname);
-      if(old != null) users.drop(old, null);
+      if(old != null) users.drop(old, "");
       users.alter(user, newname);
     }
 
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/user/UserCreate.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/user/UserCreate.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/user/UserCreate.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/user/UserCreate.java	2015-07-14 10:54:40.000000000 +0000
@@ -47,7 +47,7 @@
      */
     private Create(final String name, final String pw, final Perm perm, final User user,
         final QueryContext qc, final InputInfo info) {
-      super(UpdateType.USERCREATE, user, null, qc, info);
+      super(UpdateType.USERCREATE, user, "", qc, info);
       this.name = name;
       this.pw = pw;
       this.perm = perm;
@@ -55,7 +55,7 @@
 
     @Override
     public void apply() {
-      if(user != null) users.drop(user, null);
+      if(user != null) users.drop(user, "");
       users.create(name, pw, perm);
     }
 
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/user/UserDrop.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/user/UserDrop.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/user/UserDrop.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/user/UserDrop.java	2015-07-14 10:54:40.000000000 +0000
@@ -19,7 +19,7 @@
   public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
     checkAdmin(qc);
     final User user = toSafeUser(0, qc);
-    final String db = exprs.length > 1 ? toDB(1, qc) : null;
+    final String db = exprs.length > 1 ? toDB(1, qc) : "";
     if(user.name().equals(UserText.ADMIN)) throw USER_ADMIN.get(info);
     qc.resources.updates().add(new Drop(user, db, qc, ii), qc);
     return null;
@@ -30,12 +30,13 @@
     /**
      * Constructor.
      * @param user user
-     * @param db database (optional)
+     * @param pattern database (optional)
      * @param qc query context
      * @param info input info
      */
-    private Drop(final User user, final String db, final QueryContext qc, final InputInfo info) {
-      super(UpdateType.USERDROP, user, db, qc, info);
+    private Drop(final User user, final String pattern, final QueryContext qc,
+        final InputInfo info) {
+      super(UpdateType.USERDROP, user, pattern, qc, info);
     }
 
     @Override
@@ -43,7 +44,7 @@
       boolean global = false;
       for(final String db : patterns) global |= db == null;
       if(global) {
-        users.drop(user, null);
+        users.drop(user, "");
       } else {
         for(final String db : patterns) users.drop(user, db);
       }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/user/UserGrant.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/user/UserGrant.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/user/UserGrant.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/user/UserGrant.java	2015-07-14 10:54:40.000000000 +0000
@@ -20,9 +20,9 @@
     checkAdmin(qc);
     final User user = toSafeUser(0, qc);
     final Perm perm = toPerm(1, qc);
-    final String db = exprs.length > 2 ? toDB(2, qc) : null;
+    final String db = exprs.length > 2 ? toDB(2, qc) : "";
     if(user.name().equals(UserText.ADMIN)) throw USER_ADMIN.get(info);
-    if(db != null && (perm == Perm.CREATE || perm == Perm.ADMIN))
+    if(!db.isEmpty() && (perm == Perm.CREATE || perm == Perm.ADMIN))
       throw USER_LOCAL.get(info);
 
     qc.resources.updates().add(new Grant(user, perm, db, qc, ii), qc);
@@ -38,13 +38,13 @@
      * Constructor.
      * @param user user
      * @param perm permission
-     * @param db database
+     * @param pattern pattern
      * @param qc query context
      * @param info input info
      */
-    private Grant(final User user, final Perm perm, final String db, final QueryContext qc,
+    private Grant(final User user, final Perm perm, final String pattern, final QueryContext qc,
         final InputInfo info) {
-      super(UpdateType.USERGRANT, user, db, qc, info);
+      super(UpdateType.USERGRANT, user, pattern, qc, info);
       this.perm = perm;
     }
 
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/user/UserListDetails.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/user/UserListDetails.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/user/UserListDetails.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/user/UserListDetails.java	2015-07-14 10:54:40.000000000 +0000
@@ -20,6 +20,11 @@
 public final class UserListDetails extends UserList {
   @Override
   public Iter iter(final QueryContext qc) throws QueryException {
+    return value(qc).iter();
+  }
+
+  @Override
+  public Value value(final QueryContext qc) throws QueryException {
     checkAdmin(qc);
     final User u = exprs.length > 0 ? toUser(0, qc) : null;
 
@@ -42,11 +47,6 @@
       }
       vb.add(user);
     }
-    return vb;
-  }
-
-  @Override
-  public Value value(final QueryContext qc) throws QueryException {
-    return iter(qc).value();
+    return vb.value();
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/user/UserPassword.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/user/UserPassword.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/user/UserPassword.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/user/UserPassword.java	2015-07-14 10:54:40.000000000 +0000
@@ -34,7 +34,7 @@
      */
     private Password(final User user, final String pw, final InputInfo info,
         final QueryContext qc) {
-      super(UpdateType.USERPASSWORD, user, null, qc, info);
+      super(UpdateType.USERPASSWORD, user, "", qc, info);
       this.pw = pw;
     }
 
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/validate/ErrorHandler.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/validate/ErrorHandler.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/validate/ErrorHandler.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/validate/ErrorHandler.java	2015-07-14 10:54:40.000000000 +0000
@@ -13,7 +13,7 @@
  * @author BaseX Team 2005-15, BSD License
  * @author Christian Gruen
  */
-final class ErrorHandler extends DefaultHandler {
+public final class ErrorHandler extends DefaultHandler {
   /** Will contain all raised validation exception messages. */
   private final TokenList exceptions = new TokenList();
 
@@ -59,7 +59,7 @@
    * Returns the exception messages.
    * @return exception messages
    */
-  TokenList getExceptions() {
+  public TokenList getExceptions() {
     return exceptions;
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/validate/ValidateDtdInfo.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/validate/ValidateDtdInfo.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/validate/ValidateDtdInfo.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/validate/ValidateDtdInfo.java	2015-07-14 10:54:40.000000000 +0000
@@ -7,7 +7,6 @@
 import org.basex.io.*;
 import org.basex.io.serial.*;
 import org.basex.query.*;
-import org.basex.query.iter.*;
 import org.basex.query.value.*;
 import org.basex.query.value.item.*;
 import org.xml.sax.*;
@@ -36,19 +35,19 @@
  */
 public class ValidateDtdInfo extends ValidateFn {
   @Override
-  public Iter iter(final QueryContext qc) throws QueryException {
-    return value(qc).iter();
+  public Value value(final QueryContext qc) throws QueryException {
+    return info(qc);
   }
 
   @Override
-  public Value value(final QueryContext qc) throws QueryException {
+  public Value info(final QueryContext qc) throws QueryException {
     checkCreate(qc);
-    return process(new Validate() {
+    return process(new Validation() {
       @Override
       void process(final ErrorHandler handler)
           throws IOException, ParserConfigurationException, SAXException, QueryException {
 
-        final Item it = toItem(exprs[0], qc);
+        final Item it = toNodeOrAtomItem(exprs[0], qc);
         SerializerOptions sp = null;
 
         // integrate doctype declaration via serialization parameters
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/validate/ValidateDtd.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/validate/ValidateDtd.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/validate/ValidateDtd.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/validate/ValidateDtd.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,13 +1,7 @@
 package org.basex.query.func.validate;
 
-import static org.basex.query.QueryError.*;
-
 import org.basex.query.*;
-import org.basex.query.iter.*;
 import org.basex.query.value.*;
-import org.basex.query.value.item.*;
-import org.basex.query.value.seq.*;
-import org.basex.util.*;
 
 /**
  * Function implementation.
@@ -17,20 +11,7 @@
  */
 public final class ValidateDtd extends ValidateDtdInfo {
   @Override
-  public Iter iter(final QueryContext qc) throws QueryException {
-    final Item it = item(qc, info);
-    return it != null ? it.iter() : Empty.ITER;
-  }
-
-  @Override
   public Value value(final QueryContext qc) throws QueryException {
-    return item(qc, null);
-  }
-
-  @Override
-  public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
-    final Value seq = super.value(qc);
-    if(seq.isEmpty()) return null;
-    throw BXVA_FAIL_X.get(info, seq.iter().next());
+    return check(qc);
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/validate/ValidateFn.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/validate/ValidateFn.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/validate/ValidateFn.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/validate/ValidateFn.java	2015-07-14 10:54:40.000000000 +0000
@@ -13,6 +13,7 @@
 import org.basex.io.serial.*;
 import org.basex.query.*;
 import org.basex.query.func.*;
+import org.basex.query.iter.*;
 import org.basex.query.value.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.node.*;
@@ -28,13 +29,38 @@
  * @author Marco Lettere (greedy/verbose validation)
  */
 abstract class ValidateFn extends StandardFunc {
+  @Override
+  public final Iter iter(final QueryContext qc) throws QueryException {
+    return value(qc).iter();
+  }
+
+  /**
+   * Runs the validation process.
+   * @param qc query context.
+   * @return resulting value
+   * @throws QueryException query exception
+   */
+  public final Value check(final QueryContext qc) throws QueryException {
+    final Value seq = info(qc);
+    if(seq.isEmpty()) return Empty.SEQ;
+    throw BXVA_FAIL_X.get(info, seq.iter().next());
+  }
+
+  /**
+   * Runs the validation process and returns a string sequence.
+   * @param qc query context.
+   * @return resulting value
+   * @throws QueryException query exception
+   */
+  public abstract Value info(final QueryContext qc) throws QueryException;
+
   /**
    * Runs the specified validator.
    * @param v validator code
    * @return string sequence with warnings and errors
    * @throws QueryException query exception
    */
-  final Value process(final Validate v) throws QueryException {
+  final Value process(final Validation v) throws QueryException {
     final ErrorHandler handler = new ErrorHandler();
     try {
       v.process(handler);
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/validate/Validate.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/validate/Validate.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/validate/Validate.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/validate/Validate.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,26 +0,0 @@
-package org.basex.query.func.validate;
-
-import java.io.*;
-
-import javax.xml.parsers.*;
-
-import org.basex.io.*;
-import org.basex.query.*;
-import org.xml.sax.*;
-
-/** Abstract validator class. */
-abstract class Validate {
-  /** Temporary file instance. */
-  IOFile tmp;
-
-  /**
-   * Starts the validation.
-   * @param h error handler
-   * @throws IOException I/O exception
-   * @throws ParserConfigurationException parser configuration exception
-   * @throws SAXException SAX exception
-   * @throws QueryException query exception
-   */
-  abstract void process(ErrorHandler h)
-      throws IOException, ParserConfigurationException, SAXException, QueryException;
-}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/validate/ValidateRngInfo.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/validate/ValidateRngInfo.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/validate/ValidateRngInfo.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/validate/ValidateRngInfo.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,78 @@
+package org.basex.query.func.validate;
+
+import static org.basex.query.QueryError.*;
+
+import java.io.*;
+import java.lang.reflect.*;
+
+import org.basex.io.*;
+import org.basex.query.*;
+import org.basex.query.value.*;
+import org.basex.util.*;
+import org.xml.sax.*;
+
+/**
+ * Validates a document against a RelaxNG document.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Christian Gruen
+ */
+public class ValidateRngInfo extends ValidateFn {
+  @Override
+  public Value value(final QueryContext qc) throws QueryException {
+    return info(qc);
+  }
+
+  @Override
+  public Value info(final QueryContext qc) throws QueryException {
+    checkCreate(qc);
+    return process(new Validation() {
+      @Override
+      void process(final ErrorHandler handler) throws IOException, SAXException, QueryException {
+        final IO in = read(toNodeOrAtomItem(exprs[0], qc), qc, null);
+
+        // schema specified as string
+        IO schema = read(toNodeOrAtomItem(exprs[1], qc), qc, null);
+        tmp = createTmp(schema);
+        if(tmp != null) schema = tmp;
+
+        final boolean compact = exprs.length > 2 && toBoolean(exprs[2], qc);
+
+        try {
+          final Class<?>
+            pmb = Class.forName("com.thaiopensource.util.PropertyMapBuilder"),
+            vd = Class.forName("com.thaiopensource.validate.ValidationDriver"),
+            vp = Class.forName("com.thaiopensource.validate.ValidateProperty"),
+            pi = Class.forName("com.thaiopensource.util.PropertyId"),
+            pm = Class.forName("com.thaiopensource.util.PropertyMap"),
+            sr = Class.forName("com.thaiopensource.validate.SchemaReader"),
+            csr = Class.forName("com.thaiopensource.validate.rng.CompactSchemaReader");
+
+          final Object ehInstance = vp.getField("ERROR_HANDLER").get(null);
+          final Object pmbInstance = pmb.newInstance();
+          pi.getMethod("put", pmb, Object.class).invoke(ehInstance, pmbInstance, handler);
+
+          final Object srInstance = compact ? csr.getMethod("getInstance").invoke(null) : null;
+          final Object pmInstance = pmb.getMethod("toPropertyMap").invoke(pmbInstance);
+          final Object vdInstance = vd.getConstructor(pm, sr).newInstance(pmInstance, srInstance);
+
+          final Method vdLs = vd.getMethod("loadSchema", InputSource.class);
+          final Object loaded = vdLs.invoke(vdInstance, schema.inputSource());
+          if(Boolean.TRUE.equals(loaded)) {
+            final Method vdV = vd.getMethod("validate", InputSource.class);
+            vdV.invoke(vdInstance, in.inputSource());
+          }
+        } catch(final ClassNotFoundException ex) {
+          throw BXVA_RELAXNG_X.get(info);
+        } catch(final Exception ex) {
+          Throwable e = ex;
+          while(e.getCause() != null) {
+            Util.debug(e);
+            e = e.getCause();
+          }
+          throw BXVA_FAIL_X.get(info, e);
+        }
+      }
+    });
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/validate/ValidateRng.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/validate/ValidateRng.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/validate/ValidateRng.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/validate/ValidateRng.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,17 @@
+package org.basex.query.func.validate;
+
+import org.basex.query.*;
+import org.basex.query.value.*;
+
+/**
+ * Function implementation.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Christian Gruen
+ */
+public final class ValidateRng extends ValidateRngInfo {
+  @Override
+  public Value value(final QueryContext qc) throws QueryException {
+    return check(qc);
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/validate/ValidateXsdInfo.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/validate/ValidateXsdInfo.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/validate/ValidateXsdInfo.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/validate/ValidateXsdInfo.java	2015-07-14 10:54:40.000000000 +0000
@@ -9,9 +9,7 @@
 
 import org.basex.io.*;
 import org.basex.query.*;
-import org.basex.query.iter.*;
 import org.basex.query.value.*;
-import org.basex.query.value.item.*;
 import org.xml.sax.*;
 
 /**
@@ -43,26 +41,26 @@
  */
 public class ValidateXsdInfo extends ValidateFn {
   @Override
-  public Iter iter(final QueryContext qc) throws QueryException {
-    return value(qc).iter();
+  public Value value(final QueryContext qc) throws QueryException {
+    return info(qc);
   }
 
   @Override
-  public Value value(final QueryContext qc) throws QueryException {
+  public Value info(final QueryContext qc) throws QueryException {
     checkCreate(qc);
-    return process(new Validate() {
+    return process(new Validation() {
       @Override
       void process(final ErrorHandler handler) throws IOException, SAXException, QueryException {
-        final IO in = read(toItem(exprs[0], qc), qc, null);
+        final IO in = read(toNodeOrAtomItem(exprs[0], qc), qc, null);
+
         final SchemaFactory sf = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
         final Schema schema;
         if(exprs.length < 2) {
           // assume that schema declaration is included in document
           schema = sf.newSchema();
         } else {
-          final Item it = toItem(exprs[1], qc);
           // schema specified as string
-          IO scio = read(it, qc, null);
+          IO scio = read(toNodeOrAtomItem(exprs[1], qc), qc, null);
           tmp = createTmp(scio);
           if(tmp != null) scio = tmp;
           schema = sf.newSchema(new URL(scio.url()));
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/validate/ValidateXsd.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/validate/ValidateXsd.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/validate/ValidateXsd.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/validate/ValidateXsd.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,13 +1,7 @@
 package org.basex.query.func.validate;
 
-import static org.basex.query.QueryError.*;
-
 import org.basex.query.*;
-import org.basex.query.iter.*;
 import org.basex.query.value.*;
-import org.basex.query.value.item.*;
-import org.basex.query.value.seq.*;
-import org.basex.util.*;
 
 /**
  * Function implementation.
@@ -17,20 +11,7 @@
  */
 public final class ValidateXsd extends ValidateXsdInfo {
   @Override
-  public Iter iter(final QueryContext qc) throws QueryException {
-    final Item it = item(qc, info);
-    return it != null ? it.iter() : Empty.ITER;
-  }
-
-  @Override
   public Value value(final QueryContext qc) throws QueryException {
-    return item(qc, null);
-  }
-
-  @Override
-  public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
-    final Value seq = super.value(qc);
-    if(seq.isEmpty()) return null;
-    throw BXVA_FAIL_X.get(info, seq.iter().next());
+    return check(qc);
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/validate/Validation.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/validate/Validation.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/validate/Validation.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/validate/Validation.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,26 @@
+package org.basex.query.func.validate;
+
+import java.io.*;
+
+import javax.xml.parsers.*;
+
+import org.basex.io.*;
+import org.basex.query.*;
+import org.xml.sax.*;
+
+/** Abstract validator class. */
+abstract class Validation {
+  /** Temporary file instance. */
+  IOFile tmp;
+
+  /**
+   * Starts the validation.
+   * @param h error handler
+   * @throws IOException I/O exception
+   * @throws ParserConfigurationException parser configuration exception
+   * @throws SAXException SAX exception
+   * @throws QueryException query exception
+   */
+  abstract void process(ErrorHandler h)
+      throws IOException, ParserConfigurationException, SAXException, QueryException;
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/web/WebDecodeUrl.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/web/WebDecodeUrl.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/web/WebDecodeUrl.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/web/WebDecodeUrl.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,37 @@
+package org.basex.query.func.web;
+
+import static org.basex.query.QueryError.*;
+import static org.basex.util.Token.*;
+
+import java.io.*;
+import java.net.*;
+
+import org.basex.query.*;
+import org.basex.query.value.item.*;
+import org.basex.util.*;
+
+/**
+ * Function implementation.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Christian Gruen
+ */
+public final class WebDecodeUrl extends WebFn {
+  @Override
+  public Str item(final QueryContext qc, final InputInfo ii) throws QueryException {
+    try {
+      final byte[] uri = toToken(exprs[0], qc);
+      final byte[] token = token(URLDecoder.decode(string(uri), Strings.UTF8));
+      final TokenParser tp = new TokenParser(token);
+      while(tp.more()) {
+        if(!XMLToken.valid(tp.next())) throw BXWE_CODES_X.get(info, uri);
+      }
+      return Str.get(token);
+    } catch(final UnsupportedEncodingException ex) {
+      /* UTF8 is always supported */
+      throw Util.notExpected();
+    } catch(final IllegalArgumentException ex) {
+      throw BXWE_INVALID_X.get(info, ex.getLocalizedMessage());
+    }
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/web/WebEncodeUrl.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/web/WebEncodeUrl.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/web/WebEncodeUrl.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/web/WebEncodeUrl.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,26 @@
+package org.basex.query.func.web;
+
+import java.io.*;
+import java.net.*;
+
+import org.basex.query.*;
+import org.basex.query.value.item.*;
+import org.basex.util.*;
+
+/**
+ * Function implementation.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Christian Gruen
+ */
+public final class WebEncodeUrl extends WebFn {
+  @Override
+  public Str item(final QueryContext qc, final InputInfo ii) throws QueryException {
+    try {
+      return Str.get(URLEncoder.encode(Token.string(toToken(exprs[0], qc)), Strings.UTF8));
+    } catch(final UnsupportedEncodingException ex) {
+      /* UTF8 is always supported */
+      throw Util.notExpected();
+    }
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/xquery/XQueryEval.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/xquery/XQueryEval.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/xquery/XQueryEval.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/xquery/XQueryEval.java	2015-07-14 10:54:40.000000000 +0000
@@ -13,6 +13,7 @@
 import org.basex.query.func.*;
 import org.basex.query.iter.*;
 import org.basex.query.util.*;
+import org.basex.query.util.list.*;
 import org.basex.query.value.*;
 import org.basex.query.value.item.*;
 import org.basex.util.*;
@@ -39,13 +40,23 @@
   }
 
   @Override
-  public Iter iter(final QueryContext qc) throws QueryException {
-    return eval(qc, toToken(exprs[0], qc), null, false);
+  public final Iter iter(final QueryContext qc) throws QueryException {
+    return eval(qc).iter();
   }
 
   @Override
   public final Value value(final QueryContext qc) throws QueryException {
-    return iter(qc).value();
+    return eval(qc).value();
+  }
+
+  /**
+   * Evaluates a query.
+   * @param qc query context
+   * @return resulting value
+   * @throws QueryException query exception
+   */
+  protected ItemList eval(final QueryContext qc) throws QueryException {
+    return eval(qc, toToken(exprs[0], qc), null, false);
   }
 
   /**
@@ -57,13 +68,13 @@
    * @return resulting value
    * @throws QueryException query exception
    */
-  final ValueBuilder eval(final QueryContext qc, final byte[] qu, final String path,
+  final ItemList eval(final QueryContext qc, final byte[] qu, final String path,
       final boolean updating) throws QueryException {
 
     // bind variables and context value
     final HashMap<String, Value> bindings = toBindings(1, qc);
     final User user = qc.context.user();
-    final Perm tmp = user.perm(null);
+    final Perm tmp = user.perm("");
     Timer to = null;
 
     try(final QueryContext qctx = qc.proc(new QueryContext(qc))) {
@@ -71,10 +82,9 @@
         final Options opts = toOptions(2, Q_OPTIONS, new XQueryOptions(), qc);
         final Perm perm = Perm.get(opts.get(XQueryOptions.PERMISSION).toString());
         if(!user.has(perm)) throw BXXQ_PERM2_X.get(info, perm);
-        user.perm(perm, null);
+        user.perm(perm, "");
 
         // initial memory consumption: perform garbage collection and calculate usage
-        Performance.gc(2);
         final long mb = opts.get(XQueryOptions.MEMORY);
         if(mb != 0) {
           final long limit = Performance.memory() + (mb << 20);
@@ -83,10 +93,7 @@
             @Override
             public void run() {
               // limit reached: perform garbage collection and check again
-              if(Performance.memory() > limit) {
-                Performance.gc(1);
-                if(Performance.memory() > limit) qctx.stop();
-              }
+              if(Performance.memory() > limit) qctx.stop();
             }
           }, 500, 500);
         }
@@ -102,7 +109,7 @@
 
       // evaluate query
       try {
-        final StaticContext sctx = new StaticContext(qctx.context);
+        final StaticContext sctx = new StaticContext(qctx);
         for(final Entry<String, Value> it : bindings.entrySet()) {
           final String key = it.getKey();
           final Value val = it.getValue();
@@ -118,9 +125,9 @@
           if(qctx.updating) throw BXXQ_UPDATING.get(info);
         }
 
-        final ValueBuilder vb = new ValueBuilder();
-        cache(qctx.iter(), vb, qctx);
-        return vb;
+        final ItemList cache = new ItemList();
+        cache(qctx.iter(), cache, qctx);
+        return cache;
       } catch(final ProcException ex) {
         throw BXXQ_STOPPED.get(info);
       } catch(final QueryException ex) {
@@ -129,7 +136,7 @@
       }
 
     } finally {
-      user.perm(tmp, null);
+      user.perm(tmp, "");
       qc.proc(null);
       if(to != null) to.cancel();
     }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/xquery/XQueryInvoke.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/xquery/XQueryInvoke.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/xquery/XQueryInvoke.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/xquery/XQueryInvoke.java	2015-07-14 10:54:40.000000000 +0000
@@ -6,7 +6,7 @@
 
 import org.basex.io.*;
 import org.basex.query.*;
-import org.basex.query.iter.*;
+import org.basex.query.util.list.*;
 
 /**
  * Function implementation.
@@ -16,7 +16,7 @@
  */
 public final class XQueryInvoke extends XQueryEval {
   @Override
-  public Iter iter(final QueryContext qc) throws QueryException {
+  protected ItemList eval(final QueryContext qc) throws QueryException {
     checkCreate(qc);
     final IO io = checkPath(exprs[0], qc);
     try {
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/xquery/XQueryUpdate.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/xquery/XQueryUpdate.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/xquery/XQueryUpdate.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/xquery/XQueryUpdate.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,7 +1,7 @@
 package org.basex.query.func.xquery;
 
 import org.basex.query.*;
-import org.basex.query.iter.*;
+import org.basex.query.util.list.*;
 
 /**
  * Function implementation.
@@ -11,7 +11,7 @@
  */
 public final class XQueryUpdate extends XQueryEval {
   @Override
-  public Iter iter(final QueryContext qc) throws QueryException {
+  protected ItemList eval(final QueryContext qc) throws QueryException {
     return eval(qc, toToken(exprs[0], qc), null, true);
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/xslt/XsltTransform.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/xslt/XsltTransform.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/xslt/XsltTransform.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/xslt/XsltTransform.java	2015-07-14 10:54:40.000000000 +0000
@@ -72,7 +72,7 @@
    * @throws QueryException query exception
    */
   private IO read(final Expr ex, final QueryContext qc) throws QueryException {
-    final Item it = toItem(ex, qc);
+    final Item it = toNodeOrAtomItem(ex, qc);
     if(it instanceof ANode) {
       try {
         final IO io = new IOContent(it.serialize(SerializerOptions.get(false)).finish());
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/func/zip/ZipZipFile.java basex-8.2.3/basex-core/src/main/java/org/basex/query/func/zip/ZipZipFile.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/func/zip/ZipZipFile.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/func/zip/ZipZipFile.java	2015-07-14 10:54:40.000000000 +0000
@@ -60,18 +60,18 @@
    * Adds files to the specified zip output, or copies files from the
    * specified file.
    * @param zos output stream
-   * @param ai axis iterator
+   * @param iter axis iterator
    * @param root root path
    * @param qc query context
    * @param zf original zip file (or {@code null})
    * @throws QueryException query exception
    * @throws IOException I/O exception
    */
-  final void create(final ZipOutputStream zos, final AxisIter ai, final String root,
+  final void create(final ZipOutputStream zos, final BasicNodeIter iter, final String root,
       final ZipFile zf, final QueryContext qc) throws QueryException, IOException {
 
     final byte[] data = new byte[IO.BLOCKSIZE];
-    for(ANode node; (node = ai.next()) != null;) {
+    for(ANode node; (node = iter.next()) != null;) {
       // get entry type
       final QNm mode = node.qname();
       final boolean dir = mode.eq(Q_DIR);
@@ -106,7 +106,7 @@
           }
         } else {
           // no source reference: the child nodes are treated as file contents
-          final AxisIter ch = node.children();
+          final BasicNodeIter ch = node.children();
           final String m = attribute(node, METHOD, false);
           // retrieve first child (might be null)
           ANode n = ch.next();
@@ -171,7 +171,7 @@
   private static SerializerOptions so(final ANode node) throws BaseXException {
     // interpret query parameters
     final SerializerOptions sopts = new SerializerOptions();
-    final AxisIter ati = node.attributes();
+    final BasicNodeIter ati = node.attributes();
     for(ANode at; (at = ati.next()) != null;) {
       final byte[] name = at.qname().string();
       if(eq(name, NAME, SRC)) continue;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/iter/AxisIter.java basex-8.2.3/basex-core/src/main/java/org/basex/query/iter/AxisIter.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/iter/AxisIter.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/iter/AxisIter.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,49 +0,0 @@
-package org.basex.query.iter;
-
-import java.util.*;
-
-import org.basex.query.value.node.*;
-import org.basex.util.*;
-
-/**
- * Interface for light-weight axis iterators, throwing no exceptions.
- *
- * This class also implements the {@link Iterable} interface, which is why all of its
- * values can also be retrieved via enhanced for(for-each) loops. Note, however, that
- * using the {@link #next()} method will give you better performance.
- *
- * <b>Important</b>: to improve performance, this iterator may return the same node
- * instance with updated values. If resulting nodes are to be further processed,
- * they need to be finalized via {@link ANode#finish()}.
- *
- * @author BaseX Team 2005-15, BSD License
- * @author Christian Gruen
- */
-public abstract class AxisIter extends NodeIter implements Iterable<ANode> {
-  @Override
-  public abstract ANode next();
-
-  @Override
-  public final Iterator<ANode> iterator() {
-    return new Iterator<ANode>() {
-      /** Current node. */
-      private ANode n;
-
-      @Override
-      public boolean hasNext() {
-        n = AxisIter.this.next();
-        return n != null;
-      }
-
-      @Override
-      public ANode next() {
-        return n;
-      }
-
-      @Override
-      public void remove() {
-        throw Util.notExpected();
-      }
-    };
-  }
-}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/iter/AxisMoreIter.java basex-8.2.3/basex-core/src/main/java/org/basex/query/iter/AxisMoreIter.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/iter/AxisMoreIter.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/iter/AxisMoreIter.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,29 +0,0 @@
-package org.basex.query.iter;
-
-import org.basex.query.value.*;
-import org.basex.query.value.item.*;
-import org.basex.query.value.node.*;
-import org.basex.query.value.seq.*;
-
-/**
- * Iterator interface, extending the default iterator with a {@link #more()} method.
- *
- * @author BaseX Team 2005-15, BSD License
- * @author Christian Gruen
- */
-public abstract class AxisMoreIter extends AxisIter {
-  /** Empty iterator. */
-  public static final AxisMoreIter EMPTY = new AxisMoreIter() {
-    @Override public boolean more() { return false; }
-    @Override public ANode next() { return null; }
-    @Override public Item get(final long i) { return null; }
-    @Override public long size() { return 0; }
-    @Override public Value value() { return Empty.SEQ; }
-  };
-
-  /**
-   * Checks if more nodes are found.
-   * @return temporary node
-   */
-  public abstract boolean more();
-}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/iter/BasicNodeIter.java basex-8.2.3/basex-core/src/main/java/org/basex/query/iter/BasicNodeIter.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/iter/BasicNodeIter.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/iter/BasicNodeIter.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,59 @@
+package org.basex.query.iter;
+
+import java.util.*;
+
+import org.basex.query.value.*;
+import org.basex.query.value.node.*;
+import org.basex.query.value.seq.*;
+import org.basex.util.*;
+
+/**
+ * Basic node iterator, throwing no exceptions.
+ *
+ * This class also implements the {@link Iterable} interface, which is why all of its
+ * values can also be retrieved via enhanced for(for-each) loops. Note, however, that
+ * the {@link #next()} method will give you better performance.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Christian Gruen
+ */
+public abstract class BasicNodeIter extends NodeIter implements Iterable<ANode> {
+  /** Empty iterator. */
+  public static final BasicNodeIter EMPTY = new BasicNodeIter() {
+    @Override public ANode next() { return null; }
+    @Override public long size() { return 0; }
+    @Override public Value value() { return Empty.SEQ; }
+  };
+
+  @Override
+  public abstract ANode next();
+
+  @Override
+  public ANode get(final long i) {
+    return null;
+  }
+
+  @Override
+  public final Iterator<ANode> iterator() {
+    return new Iterator<ANode>() {
+      private ANode node;
+
+      @Override
+      public boolean hasNext() {
+        final ANode n = BasicNodeIter.this.next();
+        node = n;
+        return n != null;
+      }
+
+      @Override
+      public ANode next() {
+        return node;
+      }
+
+      @Override
+      public void remove() {
+        throw Util.notExpected();
+      }
+    };
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/iter/Iter.java basex-8.2.3/basex-core/src/main/java/org/basex/query/iter/Iter.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/iter/Iter.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/iter/Iter.java	2015-07-14 10:54:40.000000000 +0000
@@ -4,7 +4,6 @@
 import org.basex.query.value.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.seq.*;
-import org.basex.util.*;
 
 /**
  * Iterator interface.
@@ -51,27 +50,14 @@
    */
   public Value value() throws QueryException {
     // check if sequence is empty
-    Item i = next();
-    if(i == null) return Empty.SEQ;
+    final Item i1 = next();
+    if(i1 == null) return Empty.SEQ;
 
-    // if possible, allocate array with final size, and add all single items
-    Item[] item = new Item[Math.max(1, (int) size())];
-    int s = 0;
-    do {
-      if(s == item.length) item = extend(item);
-      item[s++] = i;
-    } while((i = next()) != null);
+    final Item i2 = next();
+    if(i2 == null) return i1;
 
-    // create final value
-    return Seq.get(item, s);
-  }
-
-  /**
-   * Doubles the size of an item array.
-   * @param it item array
-   * @return resulting array
-   */
-  static Item[] extend(final Item[] it) {
-    return Array.copy(it, new Item[Array.newSize(it.length)]);
+    final ValueBuilder vb = new ValueBuilder().add(i1).add(i2);
+    for(Item i; (i = next()) != null;) vb.add(i);
+    return vb.value();
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/iter/NodeIter.java basex-8.2.3/basex-core/src/main/java/org/basex/query/iter/NodeIter.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/iter/NodeIter.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/iter/NodeIter.java	2015-07-14 10:54:40.000000000 +0000
@@ -4,7 +4,7 @@
 import org.basex.query.value.node.*;
 
 /**
- * Node iterator interface.
+ * ANode iterator interface.
  *
  * @author BaseX Team 2005-15, BSD License
  * @author Christian Gruen
@@ -12,4 +12,9 @@
 public abstract class NodeIter extends Iter {
   @Override
   public abstract ANode next() throws QueryException;
+
+  @Override
+  public ANode get(final long i) throws QueryException {
+    return null;
+  }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/iter/NodeSeqBuilder.java basex-8.2.3/basex-core/src/main/java/org/basex/query/iter/NodeSeqBuilder.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/iter/NodeSeqBuilder.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/iter/NodeSeqBuilder.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,287 +0,0 @@
-package org.basex.query.iter;
-
-import java.util.*;
-
-import org.basex.data.*;
-import org.basex.query.value.*;
-import org.basex.query.value.node.*;
-import org.basex.query.value.seq.*;
-import org.basex.query.value.type.*;
-import org.basex.util.*;
-
-/**
- * This class can be used to build new node sequences.
- * At the same time, it serves as an iterator.
- *
- * @author BaseX Team 2005-15, BSD License
- * @author Christian Gruen
- */
-public final class NodeSeqBuilder extends AxisIter {
-  /** Node container. */
-  public ANode[] nodes;
-  /** Number of nodes. */
-  private int size;
-  /** Current iterator position. */
-  private int pos = -1;
-  /** Sort flag. */
-  private boolean sort;
-  /** Check incoming nodes for potential duplicates and unsorted entries. */
-  private boolean check;
-
-  /**
-   * Constructor.
-   */
-  public NodeSeqBuilder() {
-    nodes = new ANode[1];
-  }
-
-  /**
-   * Lightweight constructor, assigning the specified array of sorted nodes.
-   * @param nodes node array
-   * @param size size
-   */
-  public NodeSeqBuilder(final ANode[] nodes, final int size) {
-    this.nodes = nodes;
-    this.size = size;
-  }
-
-  /**
-   * Checks all nodes for potential duplicates and their orderedness.
-   * @return self reference
-   */
-  public NodeSeqBuilder check() {
-    check = true;
-    return this;
-  }
-
-  /**
-   * Returns the specified node.
-   * @param i node offset
-   * @return node
-   */
-  public ANode get(final int i) {
-    return nodes[i];
-  }
-
-  /**
-   * Deletes a value at the specified position.
-   * @param p deletion position
-   */
-  public void delete(final int p) {
-    Array.move(nodes, p + 1, -1, --size - p);
-  }
-
-  /**
-   * Adds a node.
-   * @param n node to be added
-   */
-  public void add(final ANode n) {
-    if(size == nodes.length) nodes = Array.copy(nodes, new ANode[Array.newSize(size)]);
-    if(check && !sort && size != 0) sort = nodes[size - 1].diff(n) > 0;
-    nodes[size++] = n;
-  }
-
-  @Override
-  public ANode next() {
-    if(check) sort(sort);
-    return ++pos < size ? nodes[pos] : null;
-  }
-
-  @Override
-  public ANode get(final long i) {
-    if(check) sort(sort);
-    return i < size ? nodes[(int) i] : null;
-  }
-
-  @Override
-  public long size() {
-    if(check) sort(sort);
-    return size;
-  }
-
-  /**
-   * Sets a new item size.
-   * @param s size
-   */
-  public void size(final int s) {
-    size = s;
-  }
-
-  @Override
-  public Value value() {
-    if(check) sort(sort);
-    return Seq.get(nodes, size, NodeType.NOD);
-  }
-
-  /**
-   * Checks if binary search can be applied to this iterator, i.e.
-   * if all nodes are {@link DBNode} references and refer to the same database.
-   * @return result of check
-   */
-  public boolean dbnodes() {
-    if(check) sort(sort);
-
-    final Data data = size > 0 ? nodes[0].data() : null;
-    if(data == null) return false;
-    for(int s = 1; s < size; ++s) if(data != nodes[s].data()) return false;
-    return true;
-  }
-
-  /**
-   * Checks if the iterator contains a database node with the specified pre value.
-   * @param n node to be found
-   * @param db indicates if all nodes are sorted {@link DBNode} references
-   * @return position, or {@code -1}
-   */
-  public int indexOf(final ANode n, final boolean db) {
-    if(db) return n instanceof DBNode ? Math.max(binarySearch((DBNode) n, 0, size), -1) : -1;
-    final long sz = size();
-    for(int s = 0; s < sz; ++s) if(nodes[s].is(n)) return s;
-    return -1;
-  }
-
-  /**
-   * Performs a binary search on the given range of this sequence iterator,
-   * assuming that all nodes are {@link DBNode}s from the same {@link Data}
-   * instance (i.e., {@link #dbnodes()} returns {@code true}).
-   * @param n node to find
-   * @param start start of the search interval
-   * @param length length of the search interval
-   * @return position of the item or {@code -insertPosition - 1} if not found
-   */
-  public int binarySearch(final DBNode n, final int start, final int length) {
-    if(size == 0 || n.data != nodes[0].data()) return -start - 1;
-    int l = start, r = start + length - 1;
-    while(l <= r) {
-      final int m = l + r >>> 1;
-      final int npre = ((DBNode) nodes[m]).pre;
-      if(npre == n.pre) return m;
-      if(npre < n.pre) l = m + 1;
-      else r = m - 1;
-    }
-    return -(l + 1);
-  }
-
-  /**
-   * Sorts the nodes if necessary.
-   * @return self reference
-   */
-  public NodeSeqBuilder sort() {
-    if(check) sort(sort);
-    return this;
-  }
-
-  /**
-   * Sorts the nodes.
-   * @param force force sort
-   */
-  private void sort(final boolean force) {
-    check = false;
-    if(size > 1) {
-      // sort arrays and remove duplicates
-      if(force) sort(0, size);
-
-      // remove duplicates and merge scores
-      int i = 1;
-      for(int j = 1; j < size; ++j) {
-        while(j < size && nodes[i - 1].is(nodes[j])) j++;
-        if(j < size) nodes[i++] = nodes[j];
-      }
-      size = i;
-    }
-  }
-
-  /**
-   * Recursively sorts the specified items via QuickSort
-   * (derived from Java's sort algorithms).
-   * @param s start position
-   * @param e end position
-   */
-  private void sort(final int s, final int e) {
-    if(e < 7) {
-      for(int i = s; i < e + s; ++i)
-        for(int j = i; j > s && nodes[j - 1].diff(nodes[j]) > 0; j--) s(j, j - 1);
-      return;
-    }
-
-    int m = s + (e >> 1);
-    if(e > 7) {
-      int l = s;
-      int n = s + e - 1;
-      if(e > 40) {
-        final int k = e >>> 3;
-        l = m(l, l + k, l + (k << 1));
-        m = m(m - k, m, m + k);
-        n = m(n - (k << 1), n - k, n);
-      }
-      m = m(l, m, n);
-    }
-    final ANode v = nodes[m];
-
-    int a = s, b = a, c = s + e - 1, d = c;
-    while(true) {
-      while(b <= c) {
-        final int h = nodes[b].diff(v);
-        if(h > 0) break;
-        if(h == 0) s(a++, b);
-        ++b;
-      }
-      while(c >= b) {
-        final int h = nodes[c].diff(v);
-        if(h < 0) break;
-        if(h == 0) s(c, d--);
-        --c;
-      }
-      if(b > c) break;
-      s(b++, c--);
-    }
-
-    final int n = s + e;
-    int k = Math.min(a - s, b - a);
-    s(s, b - k, k);
-    k = Math.min(d - c, n - d - 1);
-    s(b, n - k, k);
-
-    if((k = b - a) > 1) sort(s, k);
-    if((k = d - c) > 1) sort(n - k, k);
-  }
-
-  /**
-   * Swaps x[a .. (a+n-1)] with x[b .. (b+n-1)].
-   * @param a first offset
-   * @param b second offset
-   * @param n number of values
-   */
-  private void s(final int a, final int b, final int n) {
-    for(int i = 0; i < n; ++i) s(a + i, b + i);
-  }
-
-  /**
-   * Returns the index of the median of the three indexed integers.
-   * @param a first offset
-   * @param b second offset
-   * @param c thirst offset
-   * @return median
-   */
-  private int m(final int a, final int b, final int c) {
-    return nodes[a].diff(nodes[b]) < 0 ?
-      nodes[b].diff(nodes[c]) < 0 ? b : nodes[a].diff(nodes[c]) < 0 ? c : a :
-      nodes[b].diff(nodes[c]) > 0 ? b : nodes[a].diff(nodes[c]) > 0 ? c : a;
-  }
-
-  /**
-   * Swaps two entries.
-   * @param a first position
-   * @param b second position
-   */
-  private void s(final int a, final int b) {
-    final ANode tmp = nodes[a];
-    nodes[a] = nodes[b];
-    nodes[b] = tmp;
-  }
-
-  @Override
-  public String toString() {
-    return Util.className(this) + Arrays.toString(Arrays.copyOf(nodes, size));
-  }
-}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/iter/ValueBuilder.java basex-8.2.3/basex-core/src/main/java/org/basex/query/iter/ValueBuilder.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/iter/ValueBuilder.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/iter/ValueBuilder.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,175 +0,0 @@
-package org.basex.query.iter;
-
-import java.io.*;
-import java.util.*;
-
-import org.basex.data.*;
-import org.basex.io.out.*;
-import org.basex.io.serial.*;
-import org.basex.query.value.*;
-import org.basex.query.value.array.Array;
-import org.basex.query.value.item.*;
-import org.basex.query.value.seq.*;
-import org.basex.util.*;
-
-/**
- * This class can be used to build new sequences.
- * At the same time, it may serve as an iterator.
- *
- * @author BaseX Team 2005-15, BSD License
- * @author Christian Gruen
- */
-public final class ValueBuilder extends ValueIter implements Result {
-  /** Item container. */
-  private Item[] items;
-  /** Number of items. */
-  private int size;
-  /** Current iterator position. */
-  private int pos = -1;
-
-  /**
-   * Constructor.
-   */
-  public ValueBuilder() {
-    this(1);
-  }
-
-  /**
-   * Constructor.
-   * @param capacity initial capacity
-   */
-  public ValueBuilder(final int capacity) {
-    items = new Item[capacity];
-  }
-
-  /**
-   * Constructor.
-   * @param items initial items
-   * @param size initial size
-   */
-  public ValueBuilder(final Item[] items, final int size) {
-    this.items = items;
-    this.size = size;
-  }
-
-  /**
-   * Adds the contents of a value.
-   * @param value value to be added
-   * @return self reference
-   */
-  public ValueBuilder add(final Value value) {
-    if(value instanceof Item) return add((Item) value);
-
-    final int s = size;
-    Item[] tmp = items;
-    for(final long sz = value.size(); tmp.length - s < sz;) tmp = extend(tmp);
-    size = s + value.writeTo(tmp, s);
-    items = tmp;
-    return this;
-  }
-
-  /**
-   * Adds a single item.
-   * @param item item to be added
-   * @return self reference
-   */
-  public ValueBuilder add(final Item item) {
-    final int s = size;
-    Item[] tmp = items;
-    if(s == tmp.length) tmp = extend(tmp);
-    tmp[s] = item;
-    size = s + 1;
-    items = tmp;
-    return this;
-  }
-
-  /**
-   * Adds flattened arrays.
-   * @param it current item
-   */
-  public void addFlattened(final Item it) {
-    if(it instanceof Array) {
-      final Iterator<Value> iter = ((Array) it).members();
-      while(iter.hasNext()) {
-        for(final Item i : iter.next()) addFlattened(i);
-      }
-    } else {
-      add(it);
-    }
-  }
-
-  @Override
-  public void serialize(final Serializer ser) throws IOException {
-    for(int c = 0; c < size && !ser.finished(); ++c) serialize(ser, c);
-  }
-
-  @Override
-  public void serialize(final Serializer ser, final int n) throws IOException {
-    ser.serialize(items[n]);
-  }
-
-  @Override
-  public Item next() {
-    return ++pos < size ? items[pos] : null;
-  }
-
-  /**
-   * Sets the iterator size.
-   * @param s size
-   */
-  public void size(final int s) {
-    size = s;
-  }
-
-  @Override
-  public long size() {
-    return size;
-  }
-
-  /**
-   * Returns the internal item container.
-   * @return items
-   */
-  public Item[] items() {
-    return items;
-  }
-
-  @Override
-  public Item get(final long i) {
-    return items[(int) i];
-  }
-
-  /**
-   * Sets an item to the specified position.
-   * @param i index
-   * @param item item to be set
-   */
-  public void set(final int i, final Item item) {
-    items[i] = item;
-  }
-
-  /**
-   * Returns the cached items as value.
-   * @return sequence (internal representation!)
-   */
-  @Override
-  public Value value() {
-    return Seq.get(items, size);
-  }
-
-  @Override
-  public String serialize() throws IOException {
-    final ArrayOutput ao = new ArrayOutput();
-    serialize(Serializer.get(ao));
-    return ao.toString();
-  }
-
-  @Override
-  public String toString() {
-    try {
-      return serialize();
-    } catch(final IOException ex) {
-      throw Util.notExpected(ex);
-    }
-  }
-}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/MainModule.java basex-8.2.3/basex-core/src/main/java/org/basex/query/MainModule.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/MainModule.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/MainModule.java	2015-07-14 10:54:40.000000000 +0000
@@ -8,6 +8,7 @@
 import org.basex.query.func.*;
 import org.basex.query.iter.*;
 import org.basex.query.util.*;
+import org.basex.query.util.list.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.node.*;
 import org.basex.query.value.type.*;
@@ -82,17 +83,12 @@
    * @return result
    * @throws QueryException evaluation exception
    */
-  ValueBuilder cache(final QueryContext qc) throws QueryException {
+  ItemList cache(final QueryContext qc) throws QueryException {
     final int fp = scope.enter(qc);
     try {
       final Iter iter = expr.iter(qc);
-      final ValueBuilder cache;
-      if(iter instanceof ValueBuilder) {
-        cache = (ValueBuilder) iter;
-      } else {
-        cache = new ValueBuilder(Math.max(1, (int) iter.size()));
-        for(Item it; (it = iter.next()) != null;) cache.add(it);
-      }
+      final ItemList cache = new ItemList(Math.max(1, (int) iter.size()));
+      for(Item it; (it = iter.next()) != null;) cache.add(it);
       if(declType != null) declType.treat(cache.value(), info);
       return cache;
 
@@ -108,7 +104,7 @@
    * @throws QueryException query exception
    */
   Iter iter(final QueryContext qc) throws QueryException {
-    if(declType != null) return cache(qc);
+    if(declType != null) return cache(qc).iter();
 
     final int fp = scope.enter(qc);
     final Iter iter = expr.iter(qc);
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/QueryContext.java basex-8.2.3/basex-core/src/main/java/org/basex/query/QueryContext.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/QueryContext.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/QueryContext.java	2015-07-14 10:54:40.000000000 +0000
@@ -26,6 +26,8 @@
 import org.basex.query.iter.*;
 import org.basex.query.up.*;
 import org.basex.query.util.collation.*;
+import org.basex.query.util.ft.*;
+import org.basex.query.util.list.*;
 import org.basex.query.value.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.node.*;
@@ -99,7 +101,7 @@
   /** Current Date. */
   public Item date;
   /** Current DateTime. */
-  public Item dtm;
+  public Item datm;
   /** Current Time. */
   public Item time;
   /** Current timezone. */
@@ -107,9 +109,9 @@
   /** Current nanoseconds. */
   public long nano;
 
-  /** Strings to lock defined by lock:read option. */
+  /** Strings to lock defined by read-lock option. */
   public final StringList readLocks = new StringList(0);
-  /** Strings to lock defined by lock:write option. */
+  /** Strings to lock defined by write-lock option. */
   public final StringList writeLocks = new StringList(0);
 
   /** Number of successive tail calls. */
@@ -131,15 +133,18 @@
   /** Stack of module files that are currently parsed. */
   final TokenList modStack = new TokenList();
 
-  /** Serializer options. */
-  SerializerOptions serialOpts;
   /** Initial context value. */
   MainModule ctxItem;
 
   /** Root expression of the query. */
   public MainModule root;
 
-  /** Compilation flag. */
+  /** Serialization parameters. */
+  private SerializerOptions serParams;
+  /** Indicates if the default serialization parameters are used. */
+  public boolean defaultOutput;
+
+  /** Indicates if the query has been compiled. */
   private boolean compiled;
   /** Indicates if the query context has been closed. */
   private boolean closed;
@@ -298,7 +303,8 @@
       // cache the initial context nodes
       final DBNodes nodes = context.current();
       if(nodes != null) {
-        if(!context.perm(Perm.READ, nodes.data.meta.name)) throw BASX_PERM_X.get(null, Perm.READ);
+        if(!context.perm(Perm.READ, nodes.data().meta.name))
+          throw BASX_PERM_X.get(null, Perm.READ);
         value = resources.compile(nodes);
       }
     }
@@ -343,13 +349,13 @@
       if(!updating) return root.iter(this);
 
       // cache results
-      ValueBuilder cache = root.cache(this);
+      ItemList cache = root.cache(this);
 
       final Updates updates = resources.updates;
       if(updates != null) {
         // if parent context exists, updates will be performed by main context
         if(qcParent == null) {
-          final ValueBuilder output = resources.output;
+          final ItemList output = resources.output;
 
           // copy nodes that will be affected by an update operation
           final HashSet<Data> datas = updates.prepare(this);
@@ -367,7 +373,7 @@
           }
         }
       }
-      return cache;
+      return cache.iter();
 
     } catch(final StackOverflowError ex) {
       Util.debug(ex);
@@ -381,7 +387,7 @@
    * @param datas data references
    * @param dbs database names
    */
-  private void copy(final ValueBuilder cache, final HashSet<Data> datas, final StringList dbs) {
+  private void copy(final ItemList cache, final HashSet<Data> datas, final StringList dbs) {
     final long cs = cache.size();
     for(int c = 0; c < cs; c++) {
       final Item it = cache.get(c);
@@ -427,6 +433,7 @@
   public void databases(final LockResult lr) {
     lr.read.add(readLocks);
     lr.write.add(writeLocks);
+    // use global locking if referenced databases cannot be statically determined
     if(root == null || !root.databases(lr, this) ||
        ctxItem != null && !ctxItem.databases(lr, this)) {
       if(updating) lr.writeAll = true;
@@ -526,12 +533,15 @@
   }
 
   /**
-   * Returns the query-specific or global serialization parameters.
+   * Returns query-specific or default serialization parameters.
    * @return serialization parameters
    */
   public SerializerOptions serParams() {
-    return serialOpts != null ? serialOpts :
-      new SerializerOptions(context.options.get(MainOptions.SERIALIZER));
+    if(serParams == null) {
+      serParams = new SerializerOptions(context.options.get(MainOptions.SERIALIZER));
+      defaultOutput = root != null;
+    }
+    return serParams;
   }
 
   /**
@@ -544,7 +554,7 @@
   }
 
   /**
-   * Sets full-text options.
+   * Assigns full-text options.
    * @param opt full-text options
    */
   public void ftOpt(final FTOpt opt) {
@@ -552,6 +562,24 @@
   }
 
   /**
+   * Creates and returns an XML query plan (expression tree) for this query.
+   * @return query plan
+   */
+  public FElem plan() {
+    // only show root node if functions or variables exist
+    final FElem e = new FElem(QueryText.PLAN);
+    e.add(QueryText.COMPILED, token(compiled));
+    if(root != null) {
+      for(final StaticScope scp : QueryCompiler.usedDecls(root)) scp.plan(e);
+      root.plan(e);
+    } else {
+      funcs.plan(e);
+      vars.plan(e);
+    }
+    return e;
+  }
+
+  /**
    * Indicates that the query contains any updating expressions.
    */
   public void updating() {
@@ -592,63 +620,48 @@
   // CLASS METHODS ======================================================================
 
   /**
-   * Evaluates the expression with the specified context set.
+   * This function is called by the GUI; use {@link #iter()} instead.
+   * Caches and returns the result of the specified query. If all nodes are of the same database
+   * instance, the returned value will be of type {@link DBNodes}.
+   * @param max maximum number of results to cache (negative: return all values)
    * @return resulting value
    * @throws QueryException query exception
    */
-  Result execute() throws QueryException {
-    // limit number of hits to be returned and displayed
-    int max = context.options.get(MainOptions.MAXHITS);
-    if(max < 0) max = Integer.MAX_VALUE;
+  Value cache(final int max) throws QueryException {
+    final int mx = max >= 0 ? max : Integer.MAX_VALUE;
 
     // evaluates the query
     final Iter ir = iter();
-    final ValueBuilder vb = new ValueBuilder();
+    final ItemList cache;
     Item it;
 
     // check if all results belong to the database of the input context
     final Data data = resources.globalData();
-    if(serialOpts == null && data != null) {
+    if(defaultOutput && data != null) {
       final IntList pres = new IntList();
-      while((it = ir.next()) != null) {
+      while((it = ir.next()) != null && it.data() == data && pres.size() < mx) {
         checkStop();
-        if(it.data() != data) break;
-        if(pres.size() < max) pres.add(((DBNode) it).pre);
+        pres.add(((DBNode) it).pre());
       }
 
+      // all results processed: return compact node sequence
       final int ps = pres.size();
-      // all nodes have been processed: return compact node sequence
-      if(it == null || ps == max) return ps == 0 ? vb : new DBNodes(data, ftPosData, pres.finish());
+      if(it == null || ps == mx) return new DBNodes(data, pres.finish()).ftpos(ftPosData);
 
       // otherwise, add nodes to standard iterator
-      for(int p = 0; p < ps; ++p) vb.add(new DBNode(data, pres.get(p)));
-      vb.add(it);
+      cache = new ItemList();
+      for(int p = 0; p < ps; p++) cache.add(new DBNode(data, pres.get(p)));
+      cache.add(it);
+    } else {
+      cache = new ItemList();
     }
 
     // use standard iterator
-    while((it = ir.next()) != null) {
+    while((it = ir.next()) != null && cache.size() < mx) {
       checkStop();
-      if(vb.size() < max) vb.add(it.materialize(null));
+      cache.add(it.materialize(null));
     }
-    return vb;
-  }
-
-  /**
-   * Recursively builds a query plan.
-   * @return resulting node
-   */
-  public FElem plan() {
-    // only show root node if functions or variables exist
-    final FElem e = new FElem(QueryText.PLAN);
-    e.add(QueryText.COMPILED, token(compiled));
-    if(root != null) {
-      for(final StaticScope scp : QueryCompiler.usedDecls(root)) scp.plan(e);
-      root.plan(e);
-    } else {
-      funcs.plan(e);
-      vars.plan(e);
-    }
-    return e;
+    return cache.value();
   }
 
   // PRIVATE METHODS ====================================================================
@@ -662,7 +675,7 @@
    * @throws QueryException query exception
    */
   private Value cast(final Object val, final String type) throws QueryException {
-    final StaticContext sc = root != null ? root.sc : new StaticContext(context);
+    final StaticContext sc = root != null ? root.sc : new StaticContext(this);
 
     // String input
     Object vl = val;
@@ -679,7 +692,7 @@
 
       // sub types overriding the global value (value \2 type)
       if(string.indexOf('\2') != -1) {
-        final ValueBuilder vb = new ValueBuilder(strings.size());
+        final ValueBuilder vb = new ValueBuilder();
         for(final String str : strings) {
           final int i = str.indexOf('\2');
           final String s = i == -1 ? str : str.substring(0, i);
@@ -732,7 +745,7 @@
       if(vl instanceof Item) return tp.cast((Item) vl, this, sc, null);
       // cast sequence
       final Value v = (Value) vl;
-      final ValueBuilder seq = new ValueBuilder((int) v.size());
+      final ValueBuilder seq = new ValueBuilder();
       for(final Item i : v) seq.add(tp.cast(i, this, sc, null));
       return seq.value();
     }
@@ -740,7 +753,7 @@
     if(vl instanceof String[]) {
       // cast string array
       final String[] strings = (String[]) vl;
-      final ValueBuilder seq = new ValueBuilder(strings.length);
+      final ValueBuilder seq = new ValueBuilder();
       for(final String s : strings) seq.add(tp.cast(s, this, sc, null));
       return seq.value();
     }
@@ -806,15 +819,15 @@
    */
   public QueryContext initDateTime() throws QueryException {
     if(time == null) {
-      final Date d = Calendar.getInstance().getTime();
-      final String zon = DateTime.format(d, DateTime.ZONE);
-      final String ymd = DateTime.format(d, DateTime.DATE);
-      final String hms = DateTime.format(d, DateTime.TIME);
-      final String zn = zon.substring(0, 3) + ':' + zon.substring(3);
-      time = new Tim(token(hms + zn), null);
-      date = new Dat(token(ymd + zn), null);
-      dtm = new Dtm(token(ymd + 'T' + hms + zn), null);
-      zone = new DTDur(Strings.toInt(zon.substring(0, 3)), Strings.toInt(zon.substring(3)));
+      final Date dt = Calendar.getInstance().getTime();
+      final String ymd = DateTime.format(dt, DateTime.DATE);
+      final String hms = DateTime.format(dt, DateTime.TIME);
+      final String zon = DateTime.format(dt, DateTime.ZONE);
+      final String znm = zon.substring(0, 3), zns = zon.substring(3);
+      time = new Tim(token(hms + znm + ':' + zns), null);
+      date = new Dat(token(ymd + znm + ':' + zns), null);
+      datm = new Dtm(token(ymd + 'T' + hms + znm + ':' + zns), null);
+      zone = new DTDur(Strings.toInt(znm), Strings.toInt(zns));
       nano = System.nanoTime();
     }
     return this;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/QueryError.java basex-8.2.3/basex-core/src/main/java/org/basex/query/QueryError.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/QueryError.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/QueryError.java	2015-07-14 10:54:40.000000000 +0000
@@ -50,9 +50,11 @@
   // Admin module
 
   /** FODC0001. */
-  BXCA_TODAY(FOAD, 1, "Today's log file cannot be deleted."),
+  BXAD_TODAY(FOAD, 1, "Today's log file cannot be deleted."),
   /** FODC0002. */
-  BXCA_DELETE_X(FOAD, 2, "Log file could not be deleted: %."),
+  BXAD_DELETE_X(FOAD, 2, "Log file could not be deleted: %."),
+  /** FODC0003. */
+  BXAD_TYPE_X(FOAD, 3, "Log type must consist of uppercase letters: \"%\"."),
 
   // Client module
 
@@ -109,8 +111,6 @@
   BXDB_RENAME_X(BXDB, 8, "Invalid target path: %."),
   /** BXDB0009. */
   BXDB_RANGE_X_X_X(BXDB, 9, "Database '%' has no node with % value %."),
-  /** BXDB0010. */
-  BXDB_EVENT_X(BXDB, 10, "Event '%' is unknown."),
   /** BXDB0011. */
   BXDB_NAME_X(BXDB, 11, "Invalid database name '%'."),
   /** BXDB0012. */
@@ -155,6 +155,8 @@
   BXJS_PARSEML_X(BXJS, 1, "JsonML parser: %."),
   /** BXJS0002. */
   BXJS_SERIAL_X(BXJS, 2, "JSON serializer: %."),
+  /** BXJS0003. */
+  BXJS_INVALID_X(BXJS, 1, "'%':'%' is not supported by the target format."),
 
   // Process module
 
@@ -220,9 +222,18 @@
   // Validation module
 
   /** BXVA0001. */
-  BXVA_FAIL_X(BXVA, 1, "Validation failed. %"),
+  BXVA_FAIL_X(BXVA, 1, "Validation failed: %"),
   /** BXVA0002. */
-  BXVA_START_X(BXVA, 2, "Validation could not be started. %"),
+  BXVA_START_X(BXVA, 2, "Validation could not be started: %"),
+  /** BXVA0003. */
+  BXVA_RELAXNG_X(BXVA, 3, "RelaxNG validation is not available."),
+
+  // Web module
+
+  /** BXWE0001. */
+  BXWE_INVALID_X(BXWE, 2, "%."),
+  /** BXWE0002. */
+  BXWE_CODES_X(BXWE, 2, "URL contains invalid characters: %"),
 
   // XQuery module
 
@@ -363,15 +374,17 @@
   CX_SIGTYPINV(CX, 28, "Signature type is not supported."),
 
   /** File error. */
-  FILE_NOT_FOUND_X(FILE, "not-found", "File '%' does not exist."),
+  FILE_NOT_FOUND_X(FILE, "not-found", "'%' does not exist."),
   /** File error. */
-  FILE_EXISTS_X(FILE, "exists", "File '%' already exists."),
+  FILE_EXISTS_X(FILE, "exists", "'%' already exists."),
   /** File error. */
-  FILE_NO_DIR_X(FILE, "no-dir", "Path '%' is no directory."),
+  FILE_NO_DIR_X(FILE, "no-dir", "'%' is no directory."),
   /** File error. */
-  FILE_IS_DIR_X(FILE, "is-dir", "Path '%' is a directory."),
+  FILE_IS_DIR_X(FILE, "is-dir", "'%' is a directory."),
   /** File error. */
-  FILE_ID_DIR2_X(FILE, "is-dir", "Path '%' is a non-empty directory."),
+  FILE_ID_DIR2_X(FILE, "is-dir", "'%' is a non-empty directory."),
+  /** File error. */
+  FILE_IS_RELATIVE_X(FILE, "is-relative", "Base directory is relative: '%'."),
   /** File error. */
   FILE_UNKNOWN_ENCODING_X(FILE, "unknown-encoding", "Unknown encoding '%'."),
   /** File error. */
@@ -522,6 +535,10 @@
   JSON_OPT_X(FOJS, 5, "%"),
   /** FOJS0005. */
   JSON_FUNC_OPT_X_X(FOJS, 5, "% expected, % found."),
+  /** FOJS0006. */
+  JSON_INVALID_X(FOJS, 6, "%"),
+  /** FOJS0007. */
+  JSON_ESCAPE_X(FOJS, 7, "Invalid escape sequence: %."),
 
   /** FOMP0001. */
   MAP_TZ(FOMP, 1, "Map cannot contain keys with and without timezone."),
@@ -1133,7 +1150,7 @@
   /** XQST0097. */
   INVDECZERO_X(XQST, 97, "Zero-digit property must be Unicode digit with value zero: '%'."),
   /** XQST0098. */
-  DUPLDECFORM_X(XQST, 98, "Duplicate use of decimal-format '%'."),
+  DUPLDECFORM_X(XQST, 98, "Clash of decimal format properties: '%'."),
   /** XQST0099. */
   DUPLITEM(XQST, 99, "Duplicate declaration of context value."),
   /** XQST0103. */
@@ -1345,6 +1362,7 @@
     /** BXSL Error type. */ BXSL(BXERR_PREFIX, BXERRORS_URI),
     /** BXSQ Error type. */ BXSQ(BXERR_PREFIX, BXERRORS_URI),
     /** BXVA Error type. */ BXVA(BXERR_PREFIX, BXERRORS_URI),
+    /** BXWE Error type. */ BXWE(BXERR_PREFIX, BXERRORS_URI),
     /** BXXQ Error type. */ BXXQ(BXERR_PREFIX, BXERRORS_URI),
     /** HASH Error type. */ HASH(BXERR_PREFIX, BXERRORS_URI),
     /** UNIT Error type. */ UNIT(UNIT_PREFIX,  UNIT_URI),
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/QueryParser.java basex-8.2.3/basex-core/src/main/java/org/basex/query/QueryParser.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/QueryParser.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/QueryParser.java	2015-07-14 10:54:40.000000000 +0000
@@ -21,7 +21,7 @@
 import org.basex.query.expr.CmpN.OpN;
 import org.basex.query.expr.CmpV.OpV;
 import org.basex.query.expr.Expr.Flag;
-import org.basex.query.expr.Context;
+import org.basex.query.expr.ContextValue;
 import org.basex.query.expr.List;
 import org.basex.query.expr.constr.*;
 import org.basex.query.expr.ft.*;
@@ -34,7 +34,6 @@
 import org.basex.query.expr.path.Test.Kind;
 import org.basex.query.func.*;
 import org.basex.query.func.fn.*;
-import org.basex.query.iter.*;
 import org.basex.query.up.expr.*;
 import org.basex.query.util.*;
 import org.basex.query.util.collation.*;
@@ -134,7 +133,7 @@
     // set path to query file
     final MainOptions opts = qc.context.options;
     final String bi = path != null ? path : opts.get(MainOptions.QUERYPATH);
-    final StaticContext sctx = sc != null ? sc : new StaticContext(qc.context);
+    final StaticContext sctx = sc != null ? sc : new StaticContext(qc);
     if(!bi.isEmpty()) sctx.baseURI(bi);
     this.sc = sctx;
 
@@ -412,41 +411,44 @@
         final InputInfo info = info();
         final QNm name = eQName(QNAME_X, XQ_URI);
 
-        final ValueBuilder vb = new ValueBuilder();
+        final ItemList items = new ItemList();
         if(wsConsumeWs(PAREN1)) {
           do {
             final Expr ex = literal();
             if(!(ex instanceof Item)) throw error(ANNVALUE);
-            vb.add((Item) ex);
+            items.add((Item) ex);
           } while(wsConsumeWs(COMMA));
           wsCheck(PAREN2);
         }
         skipWs();
 
         final Annotation sig = Annotation.get(name);
+        // annotation is not statically known...
         if(sig == null) {
           // reject unknown annotations with pre-defined namespaces, ignore others
           final byte[] uri = name.uri();
-          if(NSGlobal.prefix(uri).length == 0 || eq(uri, LOCAL_URI, ERROR_URI)) continue;
-          throw (NSGlobal.reserved(uri) ? ANNWHICH_X_X : BASX_ANNOT_X_X).get(
-              info, '%', name.string());
-        }
-        // check if annotation is specified more than once
-        if(sig.single && anns.contains(sig)) throw BASX_TWICE_X_X.get(info, '%', sig.id());
-
-        final long arity = vb.size();
-        if(arity < sig.minMax[0] || arity > sig.minMax[1])
-          throw BASX_ANNNUM_X_X_X.get(info, sig, arity, arity == 1 ? "" : "s");
-        final int al = sig.args.length;
-        for(int a = 0; a < arity; a++) {
-          final SeqType st = sig.args[Math.min(al - 1, a)];
-          final Item it = vb.get(a);
-          if(!st.instance(it)) throw BASX_ANNTYPE_X_X_X.get(info, sig, st, it.seqType());
-        }
-
-        final Item[] args = new Item[(int) vb.size()];
-        vb.value().writeTo(args, 0);
-        anns.add(new Ann(info, sig, args));
+          if(NSGlobal.prefix(uri).length != 0 && !eq(uri, LOCAL_URI, ERROR_URI)) {
+            throw (NSGlobal.reserved(uri) ? ANNWHICH_X_X : BASX_ANNOT_X_X).get(
+                info, '%', name.string());
+          }
+          anns.add(new Ann(info, name, items.finish()));
+
+        } else {
+          // check if annotation is specified more than once
+          if(sig.single && anns.contains(sig)) throw BASX_TWICE_X_X.get(info, '%', sig.id());
+
+          final long arity = items.size();
+          if(arity < sig.minMax[0] || arity > sig.minMax[1])
+            throw BASX_ANNNUM_X_X_X.get(info, sig, arity, arity == 1 ? "" : "s");
+          final int al = sig.args.length;
+          for(int a = 0; a < arity; a++) {
+            final SeqType st = sig.args[Math.min(al - 1, a)];
+            final Item it = items.get(a);
+            if(!st.instance(it)) throw BASX_ANNTYPE_X_X_X.get(info, sig, st, it.seqType());
+          }
+
+          anns.add(new Ann(info, sig, items.finish()));
+        }
       } else {
         break;
       }
@@ -526,11 +528,9 @@
       // output declaration
       if(module != null) throw error(MODOUT);
 
-      if(qc.serialOpts == null) {
-        qc.serialOpts = new SerializerOptions(qc.context.options.get(MainOptions.SERIALIZER));
-      }
+      final SerializerOptions sopts = qc.serParams();
       if(!decl.add("S " + name)) throw error(OUTDUPL_X, name);
-      qc.serialOpts.parse(name, val, sc, info());
+      sopts.parse(name, val, sc, info());
 
     } else if(eq(qnm.uri(), XQ_URI)) {
       throw error(DECLOPTION_X, qnm);
@@ -772,7 +772,7 @@
    */
   public void module(final byte[] path, final byte[] uri) throws QueryException {
     // get absolute path
-    final IO io = sc.io(string(path));
+    final IO io = sc.resolve(string(path), string(uri));
     final byte[] p = token(io.path());
 
     // check if module has already been parsed
@@ -793,7 +793,7 @@
     }
 
     qc.modStack.push(p);
-    final StaticContext sub = new StaticContext(qc.context);
+    final StaticContext sub = new StaticContext(qc);
     final LibraryModule lib = new QueryParser(qu, io.path(), qc, sub).parseLibrary(false);
     final byte[] muri = lib.name.uri();
 
@@ -1335,6 +1335,7 @@
    */
   private Expr switchh() throws QueryException {
     if(!wsConsumeWs(SWITCH, PAREN1, TYPEPAR)) return null;
+    final InputInfo ii = info();
     wsCheck(PAREN1);
     final Expr expr = check(expr(), NOSWITCH);
     SwitchCase[] exprs = { };
@@ -1355,7 +1356,7 @@
       exprs = Array.add(exprs, new SwitchCase(info(), cases.finish()));
     } while(cases.size() != 1);
 
-    return new Switch(info(), expr, exprs);
+    return new Switch(ii, expr, exprs);
   }
 
   /**
@@ -1365,6 +1366,7 @@
    */
   private Expr typeswitch() throws QueryException {
     if(!wsConsumeWs(TYPESWITCH, PAREN1, TYPEPAR)) return null;
+    final InputInfo ii = info();
     wsCheck(PAREN1);
     final Expr ts = check(expr(), NOTYPESWITCH);
     wsCheck(PAREN2);
@@ -1396,7 +1398,7 @@
       closeSubScope(s);
     } while(cs);
     if(cases.length == 1) throw error(NOTYPESWITCH);
-    return new TypeSwitch(info(), ts, cases);
+    return new TypeSwitch(ii, ts, cases);
   }
 
   /**
@@ -1406,6 +1408,7 @@
    */
   private Expr iff() throws QueryException {
     if(!wsConsumeWs(IF, PAREN1, IFPAR)) return null;
+    final InputInfo ii = info();
     wsCheck(PAREN1);
     final Expr iff = check(expr(), NOIF);
     wsCheck(PAREN2);
@@ -1413,7 +1416,7 @@
     final Expr thn = check(single(), NOIF);
     if(!wsConsumeWs(ELSE)) throw error(NOIF);
     final Expr els = check(single(), NOIF);
-    return new If(info(), iff, thn, els);
+    return new If(ii, iff, thn, els);
   }
 
   /**
@@ -1425,9 +1428,10 @@
     final Expr e = and();
     if(!wsConsumeWs(OR)) return e;
 
+    final InputInfo ii = info();
     final ExprList el = new ExprList(2).add(e);
     do add(el, and()); while(wsConsumeWs(OR));
-    return new Or(info(), el.finish());
+    return new Or(ii, el.finish());
   }
 
   /**
@@ -1439,9 +1443,10 @@
     final Expr e = update();
     if(!wsConsumeWs(AND)) return e;
 
+    final InputInfo ii = info();
     final ExprList el = new ExprList(2).add(e);
     do add(el, update()); while(wsConsumeWs(AND));
-    return new And(info(), el.finish());
+    return new And(ii, el.finish());
   }
 
   /**
@@ -1775,13 +1780,16 @@
         c = curr();
       }
 
-      final byte[] v = tok.trim().toArray();
+      final byte[] value = tok.trim().toArray();
       if(eq(name.prefix(), DB_PREFIX)) {
         // project-specific declaration
         final String key = string(uc(name.local()));
         final Option<?> opt = qc.context.options.option(key);
         if(opt == null) throw error(BASX_OPTIONS_X, key);
-        el.add(new DBPragma(name, opt, v));
+        el.add(new DBPragma(name, opt, value));
+      } else if(eq(name.prefix(), BASEX_PREFIX)) {
+        // project-specific declaration
+        el.add(new BaseXPragma(name, value));
       }
       pos += 2;
     } while(wsConsumeWs(PRAGMA));
@@ -2060,7 +2068,7 @@
             new PartFunc(sc, ii, e, args, holes);
         } else if(consume(QUESTION)) {
           // parses the "Lookup" rule
-          e = new Lookup(info(), keySpecifier(), e);
+          e = new Lookup(info(), sc, keySpecifier(), e);
         }
       } while(e != old);
     }
@@ -2113,14 +2121,14 @@
     // unary lookup
     final int ip = pos;
     if(consume(QUESTION)) {
-      if(!wsConsume(COMMA) && !consume(PAREN2)) return new Lookup(info(), keySpecifier());
+      if(!wsConsume(COMMA) && !consume(PAREN2)) return new Lookup(info(), sc, keySpecifier());
       pos = ip;
     }
     // context value
     if(c == '.' && !digit(next())) {
       if(next() == '.') return null;
       consume('.');
-      return new Context(info());
+      return new ContextValue(info());
     }
     // literals
     return literal();
@@ -3040,7 +3048,7 @@
 
     wsCheck(PAREN1);
     skipWs();
-    final Test t = elem ? elementTest() : schemaTest();
+    final NodeTest t = elem ? elementTest() : schemaTest();
     wsCheck(PAREN2);
     return new DocTest(t != null ? t : Test.ELM);
   }
@@ -3050,7 +3058,7 @@
    * @return arguments
    * @throws QueryException query exception
    */
-  private Test elementTest() throws QueryException {
+  private NodeTest elementTest() throws QueryException {
     final QNm name = eQName(null, sc.elemNS);
     if(name == null && !consume(ASTERISK)) return null;
 
@@ -3064,7 +3072,7 @@
       // parse optional question mark
       wsConsume(QUESTION);
     }
-    return new NodeTest(NodeType.ELM, name, type, sc.strip);
+    return new NodeTest(NodeType.ELM, name, type);
   }
 
   /**
@@ -3072,7 +3080,7 @@
    * @return arguments
    * @throws QueryException query exception
    */
-  private Test schemaTest() throws QueryException {
+  private NodeTest schemaTest() throws QueryException {
     final QNm name = eQName(QNAME_X, sc.elemNS);
     throw error(SCHEMAINV_X, name);
   }
@@ -3094,7 +3102,7 @@
       if(type == null) type = AtomType.find(tn, true);
       if(type == null) throw error(TYPEUNDEF_X, tn);
     }
-    return new NodeTest(NodeType.ATT, name, type, sc.strip);
+    return new NodeTest(NodeType.ATT, name, type);
   }
 
   /**
@@ -3468,7 +3476,7 @@
             } else if(wsConsumeWs(AT)) {
               final String fn = string(stringLiteral());
               // optional: resolve URI reference
-              final IO fl = qc.stop != null ? qc.stop.get(fn) : sc.io(fn);
+              final IO fl = qc.stop != null ? qc.stop.get(fn) : sc.resolve(fn, null);
               if(!opt.sw.read(fl, except)) throw error(NOSTOPFILE_X, fl);
             } else if(!union && !except) {
               throw error(FTSTOP);
@@ -3504,7 +3512,7 @@
 
     final String fn = string(stringLiteral());
     // optional: resolve URI reference
-    final IO fl = qc.thes != null ? qc.thes.get(fn) : sc.io(fn);
+    final IO fl = qc.thes != null ? qc.thes.get(fn) : sc.resolve(fn, null);
     final byte[] rel = wsConsumeWs(RELATIONSHIP) ? stringLiteral() : EMPTY;
     final Expr[] range = ftRange(true);
     long min = 0;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/QueryProcessor.java basex-8.2.3/basex-core/src/main/java/org/basex/query/QueryProcessor.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/QueryProcessor.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/QueryProcessor.java	2015-07-14 10:54:40.000000000 +0000
@@ -9,13 +9,14 @@
 import org.basex.core.*;
 import org.basex.core.Context;
 import org.basex.core.locks.*;
-import org.basex.data.*;
 import org.basex.io.parse.json.*;
 import org.basex.io.serial.*;
 import org.basex.query.expr.*;
 import org.basex.query.iter.*;
+import org.basex.query.util.*;
 import org.basex.query.value.*;
 import org.basex.query.value.node.*;
+import org.basex.query.value.seq.*;
 
 /**
  * This class is an entry point for evaluating XQuery strings.
@@ -45,7 +46,7 @@
   public QueryProcessor(final String query, final Context ctx) {
     this.query = query;
     qc = proc(new QueryContext(ctx));
-    sc = new StaticContext(ctx);
+    sc = new StaticContext(qc);
   }
 
   /**
@@ -69,7 +70,8 @@
   }
 
   /**
-   * Returns a result iterator.
+   * Returns a memory-efficient result iterator. In most cases, the query will only be fully
+   * evaluated if all items of this iterator are requested.
    * @return result iterator
    * @throws QueryException query exception
    */
@@ -79,7 +81,7 @@
   }
 
   /**
-   * Returns a result value.
+   * Evaluates the query and returns the resulting value.
    * @return result value
    * @throws QueryException query exception
    */
@@ -89,13 +91,16 @@
   }
 
   /**
-   * Evaluates the specified query and returns the result.
+   * This function is called by the GUI; use {@link #iter()} or {@link #value()} instead.
+   * Caches and returns the result of the specified query. If all nodes are of the same database
+   * instance, the returned value will be of type {@link DBNodes}.
+   * @param max maximum number of results to cache (negative: return all values)
    * @return result of query
    * @throws QueryException query exception
    */
-  public Result execute() throws QueryException {
+  public Value cache(final int max) throws QueryException {
     parse();
-    return qc.execute();
+    return qc.cache(max);
   }
 
   /**
@@ -197,6 +202,16 @@
   }
 
   /**
+   * Assigns a URI resolver.
+   * @param resolver resolver
+   * @return self reference
+   */
+  public QueryProcessor uriResolver(final UriResolver resolver) {
+    sc.resolver = resolver;
+    return this;
+  }
+
+  /**
    * Returns a serializer for the given output stream.
    * Optional output declarations within the query will be included in the
    * serializer instance.
@@ -208,7 +223,7 @@
   public Serializer getSerializer(final OutputStream os) throws IOException, QueryException {
     compile();
     try {
-      return Serializer.get(os, qc.serParams());
+      return Serializer.get(os, qc.serParams()).sc(sc);
     } catch(final QueryIOException ex) {
       throw ex.getCause();
     }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/QueryResources.java basex-8.2.3/basex-core/src/main/java/org/basex/query/QueryResources.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/QueryResources.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/QueryResources.java	2015-07-14 10:54:40.000000000 +0000
@@ -11,8 +11,8 @@
 import org.basex.core.users.*;
 import org.basex.data.*;
 import org.basex.io.*;
-import org.basex.query.iter.*;
 import org.basex.query.up.*;
+import org.basex.query.util.list.*;
 import org.basex.query.util.pkg.*;
 import org.basex.query.value.*;
 import org.basex.query.value.node.*;
@@ -50,7 +50,7 @@
   private final HashMap<Class<? extends QueryResource>, QueryResource> external = new HashMap<>();
 
   /** Pending output. */
-  public final ValueBuilder output = new ValueBuilder();
+  public final ItemList output = new ItemList();
   /** Pending updates. */
   Updates updates;
 
@@ -69,9 +69,9 @@
    */
   Value compile(final DBNodes nodes) {
     // assign initial context value
-    final Data data = nodes.data;
-    final boolean all = nodes.all;
-    final Value value = DBNodeSeq.get(new IntList(nodes.pres), data, all, all);
+    final Data data = nodes.data();
+    final boolean all = nodes.all();
+    final Value value = DBNodeSeq.get(new IntList(nodes.pres()), data, all, all);
 
     // create default collection: use initial node set if it contains all
     // documents of the database. otherwise, create new node set
@@ -339,7 +339,7 @@
       final QueryInput qi = new QueryInput(paths[n]);
       nodes[n] = new DBNode(create(qi, true, baseIO, null), 0, Data.DOC);
     }
-    addCollection(Seq.get(nodes, ns, NodeType.DOC), name);
+    addCollection(ValueBuilder.value(nodes, ns, NodeType.DOC), name);
   }
 
   // PRIVATE METHODS ==============================================================================
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/QueryText.java basex-8.2.3/basex-core/src/main/java/org/basex/query/QueryText.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/QueryText.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/QueryText.java	2015-07-14 10:54:40.000000000 +0000
@@ -364,6 +364,8 @@
   String READ_LOCK = "read-lock";
   /** Option: write-lock. */
   String WRITE_LOCK = "write-lock";
+  /** Pragma: write-lock. */
+  String NON_DETERMNISTIC = "non-deterministic";
 
   // ERROR INFORMATION ========================================================
 
@@ -437,7 +439,7 @@
   /** ID token. */
   byte[] ID = token("id");
   /** IDRef token. */
-  byte[] IDREF = token("idref");
+  byte[] IDREF = token("ref");
 
   /** Error token. */
   byte[] E_CODE = token("code");
@@ -838,5 +840,4 @@
   String DEBUGLOCAL = "Local Variables";
   /** Debugging info. */
   String DEBUGGLOBAL = "Global Variables";
-
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/StaticContext.java basex-8.2.3/basex-core/src/main/java/org/basex/query/StaticContext.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/StaticContext.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/StaticContext.java	2015-07-14 10:54:40.000000000 +0000
@@ -51,14 +51,15 @@
 
   /** Static Base URI. */
   private Uri baseURI = Uri.EMPTY;
+  /** Sets a module URI resolver. */
+  UriResolver resolver;
 
   /**
    * Constructor setting the XQuery version.
-   * @param ctx database context
+   * @param qc query context
    */
-  public StaticContext(final Context ctx) {
-    final MainOptions opts = ctx.options;
-    mixUpdates = opts.get(MainOptions.MIXUPDATES);
+  public StaticContext(final QueryContext qc) {
+    mixUpdates = qc.context.options.get(MainOptions.MIXUPDATES);
   }
 
   /**
@@ -88,13 +89,14 @@
   }
 
   /**
-   * Returns an IO reference for the specified filename.
-   * If a base URI exists, it is merged with the specified filename.
-   * Otherwise, a plain reference is returned.
+   * Returns an IO reference for the specified path.
+   * If a base URI exists, it is merged with the path.
    * @param path file path
+   * @param uri module namespace (can be {@code null})
    * @return io reference
    */
-  IO io(final String path) {
+  IO resolve(final String path, final String uri) {
+    if(resolver != null) return resolver.resolve(path, uri, baseURI);
     final IO base = baseIO();
     return base != null ? base.merge(path) : IO.get(path);
   }
@@ -113,15 +115,19 @@
    */
   public void baseURI(final String uri) {
     final IO base = IO.get(uri);
+    String url;
     if(uri.isEmpty()) {
-      baseURI = Uri.EMPTY;
+      url = "";
     } else if(base instanceof IOContent) {
-      baseURI = Uri.uri(uri);
+      url = uri;
     } else if(baseURI == Uri.EMPTY) {
-      baseURI = Uri.uri(base.url());
+      url = base.url();
     } else {
-      baseURI = Uri.uri(baseIO().merge(uri).url());
+      url = baseIO().merge(uri).url();
     }
+    // #1062: check if specified URI points to a directory. if yes, add trailing slash
+    if(!url.endsWith("/") && (uri.endsWith(".") || uri.endsWith("/"))) url += '/';
+    baseURI = Uri.uri(url);
   }
 
   @Override
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/up/atomic/AtomicUpdateCache.java basex-8.2.3/basex-core/src/main/java/org/basex/query/up/atomic/AtomicUpdateCache.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/up/atomic/AtomicUpdateCache.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/up/atomic/AtomicUpdateCache.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,519 @@
+package org.basex.query.up.atomic;
+
+import java.util.*;
+
+import org.basex.data.*;
+import org.basex.util.*;
+import org.basex.util.hash.*;
+
+/**
+ * Implementation of the Atomic Update Cache (AUC).
+ *
+ * <p>A container/list for atomic updates. Updates must be added from the lowest to
+ * the highest PRE value (regarding the location of the update). Updates are finally
+ * applied by this container from the highest to the lowest PRE value (reverse document
+ * order) to support efficient structural bulk updates etc.</p>
+ *
+ * <p>If a collection of updates is carried out via the AUC there are several
+ * benefits:</p>
+ *
+ * <ol>
+ *   <li> Efficient distance adjustments after structural changes.</li>
+ *   <li> Tree-Aware Updates (TAU): identification of superfluous updates (like updating
+ *        the descendants of a deleted node).</li>
+ *   <li> Resolution of text node adjacency.</li>
+ *   <li> Merging of atomic updates to reduce number of I/Os. </li>
+ * </ol>
+ *
+ * <p>To avoid ambiguity it is not allowed to add:</p>
+ * <ul>
+ * <li> more than one destructive update like {@link Delete} or {@link Replace} operating
+ *      on the same node.</li>
+ * <li> more than one {@link Rename} or {@link UpdateValue} operating
+ *      on the same node.</li>
+ * <li> sequences like [delete X, insert N at X]: This sequence would be carried out back
+ * to front: first the insert, then the delete. This would lead to the inserted node N
+ * being deleted by the 'delete X' statement. The correct order for this sequence would
+ * be [insert N at X, delete X]. </li>
+ * <li> and so forth ... see check() function for details. </li>
+ * </ul>
+ *
+ * <p>Updates are added in a streaming fashion where the most recently added update is
+ * remembered. This avoids additional traversals of the AUC during consistency checks and
+ * further optimizations.</p>
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Lukas Kircher
+ */
+public final class AtomicUpdateCache {
+  /** List of structural updates (nodes are inserted to / deleted from the table. */
+  private final List<StructuralUpdate> struct = new ArrayList<>(1);
+  /** Value / non-structural updates like rename. */
+  private final List<BasicUpdate> val = new ArrayList<>(1);
+  /** Most recently added update buffer. Used to merge/discard updates and to detect
+   * inconsistencies on-the-fly eliminating the need to traverse all updates. */
+  private BasicUpdate recent;
+  /** Most recently added structural atomic update - if there is any. Used to calculate accumulated
+   * pre value shifts on-the-fly, as {@link BasicUpdate} don't carry this information. */
+  private BasicUpdate recentStruct;
+  /** Target data reference. */
+  public final Data data;
+
+  /**
+   * Constructor.
+   * @param data target data reference
+   */
+  public AtomicUpdateCache(final Data data) {
+    this.data = data;
+  }
+
+  /**
+   * Adds a delete atomic to the list.
+   * @param pre PRE value of the target node/update location
+   */
+  public void addDelete(final int pre) {
+    considerAtomic(Delete.getInstance(data, pre), false);
+  }
+
+  /**
+   * Adds an insert atomic to the list.
+   * @param pre PRE value of the target node/update location
+   * @param par new parent of the inserted nodes
+   * @param clip insertion sequence data clip
+   */
+  public void addInsert(final int pre, final int par, final DataClip clip) {
+    considerAtomic(clip.data.kind(clip.start) == Data.ATTR
+        ? InsertAttr.getInstance(pre, par, clip) : Insert.getInstance(pre, par, clip), false);
+  }
+
+  /**
+   * Adds a replace atomic to the list.
+   * @param pre PRE value of the target node/update location
+   * @param clip insertion sequence data clip
+   */
+  public void addReplace(final int pre, final DataClip clip) {
+    considerAtomic(Replace.getInstance(data, pre, clip), false);
+  }
+
+  /**
+   * Adds a rename atomic to the list.
+   * @param pre PRE value of the target node/update location
+   * @param name new name for the target node
+   * @param uri new uri for the target node
+   */
+  public void addRename(final int pre, final byte[] name, final byte[] uri) {
+    considerAtomic(Rename.getInstance(data, pre, name, uri), false);
+  }
+
+  /**
+   * Adds an updateValue atomic to the list.
+   * @param pre PRE value of the target node/update location
+   * @param value new value for the target node
+   */
+  public void addUpdateValue(final int pre, final byte[] value) {
+    considerAtomic(UpdateValue.getInstance(data, pre, value), false);
+  }
+
+  /**
+   * Resets the list.
+   */
+  public void clear() {
+    struct.clear();
+    val.clear();
+    recent = null;
+    recentStruct = null;
+  }
+
+  /**
+   * Adds an update to the corresponding list.
+   * @param candidate atomic update
+   * @param slack skip consistency checks etc. if true (used during text node merging)
+   */
+  private void considerAtomic(final BasicUpdate candidate, final boolean slack) {
+    // fill the one-atomic-update buffer
+    if(recent == null) {
+      recent = candidate;
+      if(recent instanceof StructuralUpdate)
+        recentStruct = candidate;
+      return;
+    }
+
+    if(candidate instanceof StructuralUpdate && recentStruct != null) {
+      ((StructuralUpdate) candidate).accumulatedShifts += recentStruct.accumulatedShifts();
+    }
+
+    // prepare & optimize incoming update
+    if(slack) {
+      add(candidate, false);
+    } else {
+      check(recent, candidate);
+      if(treeAwareUpdates(recent, candidate)) return;
+
+      final BasicUpdate m = recent.merge(data, candidate);
+      if(m != null) add(m, true);
+      else add(candidate, false);
+
+    }
+  }
+
+  /**
+   * Adds the given update to the updates/buffer depending on the type and whether it's
+   * been merged or not.
+   *
+   * @param bu update
+   * @param merged if true, the given update has been merged w/ the recent one
+   */
+  private void add(final BasicUpdate bu, final boolean merged) {
+    if(bu == null) return;
+
+    if(!merged) {
+      if(recent instanceof StructuralUpdate)
+        struct.add((StructuralUpdate) recent);
+      else val.add(recent);
+    }
+    recent = bu;
+    if(bu instanceof StructuralUpdate)
+      recentStruct = bu;
+  }
+
+  /**
+   * Flushes the buffer that contains the most previously added atomic update.
+   */
+  private void flush() {
+    if(recent != null) {
+      add(recent, false);
+      recent = null;
+      recentStruct = null;
+    }
+  }
+
+  /**
+   * Returns the number of structural updates.
+   * @return number of structural updates
+   */
+  public int updatesSize() {
+    flush();
+    return struct.size() + val.size();
+  }
+
+  /**
+   * Checks the given sequence of two updates for violations.
+   *
+   * Updates must be ordered strictly from the lowest to the highest PRE value.
+   * Deletes must follow inserts.
+   *
+   * A single node must not be affected by more than one {@link Rename},
+   * {@link UpdateValue} operation.
+   *
+   * A single node must not be affected by more than one destructive operation. These
+   * operations include {@link Replace}, {@link Delete}.
+   *
+   * @param bu1 first update in sequence
+   * @param bu2 second update in sequence
+   */
+  private static void check(final BasicUpdate bu1, final BasicUpdate bu2) {
+    // check order of location PRE, must be strictly ordered low-to-high
+    if(bu2.location < bu1.location)
+      throw Util.notExpected("Invalid order at location " + bu1.location);
+
+    if(bu2.location == bu1.location) {
+      // check invalid sequence of {@link Delete}, {@link Insert}
+      // - the inserted node would directly be deleted without this restriction
+      if(bu2 instanceof Insert || bu2 instanceof InsertAttr)
+        if(bu1 instanceof Delete)
+          throw Util.notExpected("Invalid sequence of delete, insert at location " + bu1.location);
+        else if(bu1 instanceof Replace)
+          throw Util.notExpected("Invalid sequence of replace, insert at location " + bu1.location);
+
+      // check multiple {@link Delete}, {@link Replace}
+      if(bu2.destructive() && bu1.destructive())
+        throw Util.notExpected("Multiple deletes/replaces on node " + bu1.location);
+
+      // check multiple {@link Rename}
+      if(bu2 instanceof Rename && bu1 instanceof Rename)
+        throw Util.notExpected("Multiple renames on node " + bu1.location);
+
+      // check multiple {@link UpdateValue}
+      if(bu2 instanceof UpdateValue && bu1 instanceof UpdateValue)
+        throw Util.notExpected("Multiple updates on node " + bu1.location);
+
+      /* Check invalid order of destructive/non-destructive updates to support TAU
+       *  cases like: <rename X, delete X>: node X would be deleted and then X+1 renamed,
+       *  as this shifts down to X.
+       */
+      if(bu2.destructive() && !(bu1 instanceof StructuralUpdate))
+        throw Util.notExpected("Invalid sequence of value update and destructive update at" +
+            " location " + bu1.location);
+    }
+  }
+
+  /**
+   * Checks if the second update is superfluous. An update is considered to be superfluous
+   * if it targets a position in the subtree of a to-be-removed node.
+   * @param bu1 first update in sequence
+   * @param bu2 second update in sequence
+   * @return true if second update superfluous
+   */
+  private boolean treeAwareUpdates(final BasicUpdate bu1, final BasicUpdate bu2) {
+    if(bu1.destructive()) {
+      // we determine the lowest and highest PRE values of a superfluous update
+      final int pre = bu1.location;
+      final int fol = pre + data.size(pre, data.kind(pre));
+      /* CASE 1: candidate operates on the subtree of T and appends a node to the end of
+       * the subtree (target PRE may be equal)...
+       * CASE 2: operates within subtree of T */
+      if(bu2.location <= fol && (bu2 instanceof Insert || bu2 instanceof InsertAttr) &&
+          bu2.parent >= pre && bu2.parent < fol ||
+        bu2.location < fol) {
+        return true;
+      }
+    }
+    return false;
+  }
+
+  /**
+   * Executes the updates. Resolving text node adjacency can be skipped if adjacent text
+   * nodes are not to be expected.
+   * @param mergeTexts adjacent text nodes are to be expected and must be merged
+   */
+  public void execute(final boolean mergeTexts) {
+    data.cache = true;
+    applyUpdates();
+    adjustDistances();
+    if(mergeTexts) resolveTextAdjacency();
+    data.cache = false;
+    clear();
+  }
+
+  /**
+   * Carries out structural updates.
+   */
+  public void applyUpdates() {
+    // check if previous update still in buffer
+    flush();
+    // value updates applied front-to-back, doens't matter as there are no row shifts
+    for(final BasicUpdate u : val) u.apply(data);
+    // structural updates are applied back-to-front
+    for(int i = struct.size() - 1; i >= 0; i--) struct.get(i).apply(data);
+  }
+
+  /**
+   * Adjusts distances to restore parent-child relationships that have been invalidated
+   * by structural updates.
+   *
+   * Each structural update (insert/delete) leads to a shift of higher PRE values. This
+   * invalidates parent-child relationships. Distances are only adjusted after all
+   * structural updates have been carried out to make sure each node (that has to be
+   * updated) is only touched once.
+   */
+  private void adjustDistances() {
+    // check if any distance has changed at all
+    boolean shifts = false;
+    for(final StructuralUpdate update : struct) {
+      if(update.accumulatedShifts != 0) {
+        shifts = true;
+        break;
+      }
+    }
+    if(!shifts) return;
+
+    final IntSet updatedNodes = new IntSet();
+    for(final StructuralUpdate update : struct) {
+      /* Update distance for the affected node and all following siblings of nodes
+       * on the ancestor-or-self axis. */
+      int pre = update.preOfAffectedNode + update.accumulatedShifts;
+      while(pre < data.meta.size && !updatedNodes.contains(pre)) {
+        final int kind = data.kind(pre);
+        data.dist(pre, kind, calculateNewDistance(pre, kind));
+        updatedNodes.add(pre);
+        pre += data.size(pre, kind);
+      }
+    }
+  }
+
+  /**
+   * Calculates the new distance value for the given node after updates have been applied.
+   * @param pre the new PRE value of the node after structural updates have been applied
+   * @param kind the KIND value
+   * @return new distance for the given PRE node
+   */
+  private int calculateNewDistance(final int pre, final int kind) {
+    int distanceBefore = data.dist(pre, kind);
+    final int preBefore = calculatePreValue(pre, true);
+    // document distances are not stored in table but calculated on the fly (always pre+1)
+    if(kind == Data.DOC) distanceBefore = preBefore + 1;
+    final int parentBefore = preBefore - distanceBefore;
+    final int parentAfter = calculatePreValue(parentBefore, false);
+    return pre - parentAfter;
+  }
+
+  /**
+   * Calculates the PRE value of a given node before/after updates.
+   *
+   * Finds all updates that affect the given node N. The result is than calculated based
+   * on N and the accumulated PRE value shifts introduced by these updates.
+   *
+   * If a node has been inserted at position X and this method is used to calculate the
+   * PRE value of X before updates, X is the result. As the node at position X has not
+   * existed before the insertion, its PRE value is unchanged. If in contrast the PRE
+   * value is calculated after updates, the result is X+1, as the node with the original
+   * position X has been shifted by the insertion at position X.
+   *
+   * Make sure accumulated shifts have been calculated before calling this method!
+   *
+   * @param pre PRE value
+   * @param beforeUpdates calculate PRE value before shifts/updates have been applied
+   * @return index of update, or -1
+   */
+  public int calculatePreValue(final int pre, final boolean beforeUpdates) {
+    // find update that affects the given PRE value
+    int i = find(pre, beforeUpdates);
+    // given PRE not changed by updates
+    if(i == -1) return pre;
+    // refine the search to determine accumulated shifts for the given PRE
+    i = refine(struct, i, beforeUpdates);
+    final int acm = struct.get(i).accumulatedShifts;
+    return beforeUpdates ? pre - acm : pre + acm;
+  }
+
+  /**
+   * Used to find the update that holds the accumulated shift value that is needed to
+   * recalculate the given PRE value. In a low-to-high ordered list this is the right-most
+   * update with a target PRE value smaller or equal the given PRE value, v.v.
+   *
+   * Finds the position of the update that affects the given PRE value P.
+   * If there are multiple updates whose affected PRE value equals P, the search
+   * has to be further refined as this method returns only the first match.
+   * @param pre given PRE value
+   * @param beforeUpdates compare based on PRE values before/after updates
+   * @return index of update
+   */
+  private int find(final int pre, final boolean beforeUpdates) {
+    int left = 0;
+    int right = struct.size() - 1;
+
+    while(left <= right) {
+      if(left == right) {
+        if(c(struct, left, beforeUpdates) <= pre) return left;
+        return -1;
+      }
+      if(right - left == 1) {
+        if(c(struct, right, beforeUpdates) <= pre) return right;
+        if(c(struct, left, beforeUpdates) <= pre) return left;
+        return -1;
+      }
+      final int middle = left + right >>> 1;
+      final int value = c(struct, middle, beforeUpdates);
+      if(value == pre) return middle;
+      else if(value > pre) right = middle - 1;
+      else left = middle;
+    }
+
+    // empty array
+    return -1;
+  }
+
+  /**
+   * Finds the update with the lowest index in the given list that affects the same
+   * PRE value as the update with the given index.
+   * @param updates list of updates
+   * @param index of update
+   * @param beforeUpdates find update for PRE values before updates have been applied
+   * @return update with the highest index that invalidates the distance of the given
+   * node
+   */
+  private static int refine(final List<StructuralUpdate> updates, final int index,
+      final boolean beforeUpdates) {
+    int u = index;
+    final int value = c(updates, u++, beforeUpdates);
+    final int us = updates.size();
+    while(u < us && c(updates, u, beforeUpdates) == value) u++;
+    return u - 1;
+  }
+
+  /**
+   * Recalculates the PRE value of the first node whose distance is affected by the
+   * given update.
+   * @param updates list of updates
+   * @param index index of the update
+   * @param beforeUpdates calculate PRE value before or after updates
+   * @return PRE value
+   */
+  private static int c(final List<StructuralUpdate> updates, final int index,
+      final boolean beforeUpdates) {
+    final StructuralUpdate u = updates.get(index);
+    return u.preOfAffectedNode + (beforeUpdates ? u.accumulatedShifts : 0);
+  }
+
+  /**
+   * Resolves unwanted text node adjacency which can result from structural changes in
+   * the database. Adjacent text nodes are two text nodes A and B, where
+   * PRE(B)=PRE(A)+1 and PARENT(A)=PARENT(B).
+   */
+  private void resolveTextAdjacency() {
+    // Text node merges are also gathered on a separate list to leverage optimizations.
+    final List<Delete> deletes = new LinkedList<>();
+
+    // keep track of the visited locations to avoid superfluous checks
+    int smallestVisited = Integer.MAX_VALUE;
+    // Text nodes have to be merged from the highest to the lowest pre value
+    for(int i = struct.size() - 1; i >= 0; i--) {
+      final StructuralUpdate u = struct.get(i);
+      final DataClip insseq = u.getInsertionData();
+      // calculate the new location of the update, here we have to check for adjacency
+      final int newLocation = u.location + u.accumulatedShifts - u.shifts;
+      final int beforeNewLocation = newLocation - 1;
+      // check surroundings of this location for adjacent text nodes depending on the
+      // kind of update, first the one with higher PRE values (due to shifts!)
+      // ... for insert/replace ...
+      if(insseq != null) {
+        // calculate the current following node
+        final int followingNode = newLocation + insseq.size();
+        final int beforeFollowingNode = followingNode - 1;
+        // check the nodes at the end of/after the insertion sequence
+        if(beforeFollowingNode < smallestVisited) {
+          final Delete del = mergeTextNodes(beforeFollowingNode);
+          if(del != null) deletes.add(0, del);
+          smallestVisited = beforeFollowingNode;
+        }
+      }
+      // check nodes for delete and for insert before the updated location
+      if(beforeNewLocation < smallestVisited) {
+        final Delete del = mergeTextNodes(beforeNewLocation);
+        if(del != null) deletes.add(0, del);
+        smallestVisited = beforeNewLocation;
+      }
+    }
+
+    final AtomicUpdateCache auc = new AtomicUpdateCache(data);
+    for(final Delete delete : deletes) auc.considerAtomic(delete, true);
+    deletes.clear();
+    auc.applyUpdates();
+    auc.adjustDistances();
+    auc.clear();
+  }
+
+  /**
+   * Returns atomic text node merging operations if necessary for the given node PRE and
+   * its right neighbor PRE+1.
+   * @param pre node PRE value
+   * @return list of text merging operations
+   */
+  private Delete mergeTextNodes(final int pre) {
+    final int s = data.meta.size;
+    final int b = pre + 1;
+    // don't leave table
+    if(pre >= s || b >= s || pre < 0 || b < 0) return null;
+    // only merge texts
+    if(data.kind(pre) != Data.TEXT || data.kind(b) != Data.TEXT) return null;
+    // only merge neighboring texts
+    if(data.parent(pre, Data.TEXT) != data.parent(b, Data.TEXT)) return null;
+
+    // apply text node updates on the fly and throw them away
+    UpdateValue.getInstance(data, pre, Token.concat(data.text(pre, true),
+        data.text(b, true))).
+      apply(data);
+    // deletes must be cached to add them front-to-back to atomic update list
+    return Delete.getInstance(data, b);
+  }
+}
\ No newline at end of file
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/up/atomic/BasicUpdate.java basex-8.2.3/basex-core/src/main/java/org/basex/query/up/atomic/BasicUpdate.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/up/atomic/BasicUpdate.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/up/atomic/BasicUpdate.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,70 @@
+package org.basex.query.up.atomic;
+
+import org.basex.data.*;
+
+/**
+ * Abstract atomic update.
+ * Atomic updates can only be initialized via {@link AtomicUpdateCache}.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Lukas Kircher
+ */
+public abstract class BasicUpdate {
+  /** PRE value of the target location. */
+  final int location;
+  /** Parent PRE of nodes to insert. */
+  final int parent;
+
+  /**
+   * Constructor.
+   * @param location target node location PRE
+   * @param parent parent node PRE value
+   */
+  BasicUpdate(final int location, final int parent) {
+    this.location = location;
+    this.parent = parent;
+  }
+
+  /**
+   * Getter for accumulated shifts.
+   * @return accumulated shifts, or zero if non-structural update.
+   */
+  int accumulatedShifts() {
+    return 0;
+  }
+
+  /**
+   * Applies the update to the given data instance.
+   * @param data data instance on which to execute the update
+   */
+  abstract void apply(final Data data);
+
+  /**
+   * Returns the data to be inserted (for inserts,...).
+   * @return Insertion sequence data instance
+   */
+  abstract DataClip getInsertionData();
+
+  /**
+   * Returns whether this updates destroys the target nodes identity. Used to determine
+   * superfluous operations on the subtree of the target.
+   * @return {@code true} if target node identity destroyed
+   */
+  abstract boolean destructive();
+
+  /**
+   * Merges the given update and this update if possible.
+   * @param data data reference
+   * @param bu update to merge with
+   * @return merged atomic update or null if merge not possible
+   */
+  @SuppressWarnings("unused")
+  public BasicUpdate merge(final Data data, final BasicUpdate bu) {
+    return null;
+  }
+
+  @Override
+  public String toString() {
+    return "L" + location;
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/up/atomic/Delete.java basex-8.2.3/basex-core/src/main/java/org/basex/query/up/atomic/Delete.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/up/atomic/Delete.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/up/atomic/Delete.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,67 @@
+package org.basex.query.up.atomic;
+
+import org.basex.data.*;
+
+/**
+ * Atomic update operation that deletes a node.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Lukas Kircher
+ */
+final class Delete extends StructuralUpdate {
+  /**
+   * Constructor.
+   * @param location target node location PRE
+   * @param shifts PRE value shifts introduced by update
+   * @param acc accumulated shifts
+   * @param first PRE value of the first node which distance has to be updated
+   * @param parent parent
+   */
+  private Delete(final int location, final int shifts, final int acc, final int first,
+      final int parent) {
+    super(location, shifts, acc, first, parent);
+  }
+
+  /**
+   * Factory.
+   * @param data data reference
+   * @param pre location pre value
+   * @return atomic delete
+   */
+  static Delete getInstance(final Data data, final int pre) {
+    final int k = data.kind(pre);
+    final int s = data.size(pre, k);
+    return new Delete(pre, -s, -s, pre + s, data.parent(pre, k));
+  }
+
+  @Override
+  void apply(final Data data) {
+    data.delete(location);
+  }
+
+  @Override
+  DataClip getInsertionData() {
+    return null;
+  }
+
+  @Override
+  boolean destructive() {
+    return true;
+  }
+
+  @Override
+  public String toString() {
+    return "\n Delete: " + super.toString();
+  }
+
+  @Override
+  public BasicUpdate merge(final Data data, final BasicUpdate bu) {
+    if(bu != null && parent == bu.parent && bu instanceof Insert &&
+        location - shifts == bu.location && data.kind(location) != Data.ATTR) {
+      final Insert ins = (Insert) bu;
+      return new Replace(location, shifts + ins.shifts,
+          ins.accumulatedShifts, preOfAffectedNode, ins.clip, parent);
+    }
+    return null;
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/up/atomic/InsertAttr.java basex-8.2.3/basex-core/src/main/java/org/basex/query/up/atomic/InsertAttr.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/up/atomic/InsertAttr.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/up/atomic/InsertAttr.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,61 @@
+package org.basex.query.up.atomic;
+
+import org.basex.data.*;
+
+/**
+ * Atomic update operation that inserts an attribute into a database.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Lukas Kircher
+ */
+final class InsertAttr extends StructuralUpdate {
+  /** Insertion sequence. */
+  private final DataClip clip;
+
+  /**
+   * Constructor.
+   * @param location PRE value of the target node location
+   * @param shifts row shifts
+   * @param acc accumulated row shifts
+   * @param first PRE value of the first node which distance has to be updated
+   * @param parent parent PRE value for the inserted node
+   * @param clip insert sequence data clip
+   */
+  private InsertAttr(final int location, final int shifts, final int acc, final int first,
+      final int parent, final DataClip clip) {
+    super(location, shifts, acc, first, parent);
+    this.clip = clip;
+  }
+
+  /**
+   * Factory.
+   * @param pre target location PRE
+   * @param par parent of new attribute
+   * @param clip insertion sequence
+   * @return instance
+   */
+  static InsertAttr getInstance(final int pre, final int par, final DataClip clip) {
+    final int sh = clip.size();
+    return new InsertAttr(pre, sh, sh, pre, par, clip);
+  }
+
+  @Override
+  void apply(final Data data) {
+    data.insertAttr(location, parent, clip);
+  }
+
+  @Override
+  DataClip getInsertionData() {
+    return clip;
+  }
+
+  @Override
+  boolean destructive() {
+    return false;
+  }
+
+  @Override
+  public String toString() {
+    return "\nInsertAttr: " + super.toString();
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/up/atomic/Insert.java basex-8.2.3/basex-core/src/main/java/org/basex/query/up/atomic/Insert.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/up/atomic/Insert.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/up/atomic/Insert.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,72 @@
+package org.basex.query.up.atomic;
+
+import org.basex.data.*;
+
+/**
+ * Atomic insert that inserts a given insertion sequence data instance into a database.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Lukas Kircher
+ */
+final class Insert extends StructuralUpdate {
+  /** Insertion sequence. */
+  final DataClip clip;
+
+  /**
+   * Constructor.
+   * @param location PRE value of the target node location
+   * @param shifts shifts
+   * @param acc accumulated shifts
+   * @param first PRE value of the first node which distance has to be updated
+   * @param parent parent PRE value for the inserted nodes
+   * @param clip insertion sequence data clip
+   */
+  private Insert(final int location, final int shifts, final int acc, final int first,
+      final int parent, final DataClip clip) {
+    super(location, shifts, acc, first, parent);
+    this.clip = clip;
+  }
+
+  /**
+   * Factory.
+   * @param pre target location PRE
+   * @param par parent of inserted node
+   * @param clip insertion sequence
+   * @return instance
+   */
+  static Insert getInstance(final int pre, final int par, final DataClip clip) {
+    final int s = clip.size();
+    return new Insert(pre, s, s, pre, par, clip);
+  }
+
+  @Override
+  void apply(final Data data) {
+    data.insert(location, parent, clip);
+  }
+
+  @Override
+  DataClip getInsertionData() {
+    return clip;
+  }
+
+  @Override
+  boolean destructive() {
+    return false;
+  }
+
+  @Override
+  public BasicUpdate merge(final Data data, final BasicUpdate bu) {
+    if(bu != null && parent == bu.parent && bu instanceof Delete && location == bu.location
+        && data.kind(bu.location) != Data.ATTR) {
+      final Delete del = (Delete) bu;
+      return new Replace(location, shifts + del.shifts,
+          del.accumulatedShifts, del.preOfAffectedNode, clip, parent);
+    }
+    return null;
+  }
+
+  @Override
+  public String toString() {
+    return "\n Insert: " + super.toString();
+  }
+}
\ No newline at end of file
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/up/atomic/Rename.java basex-8.2.3/basex-core/src/main/java/org/basex/query/up/atomic/Rename.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/up/atomic/Rename.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/up/atomic/Rename.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,68 @@
+package org.basex.query.up.atomic;
+
+import org.basex.data.*;
+import org.basex.util.*;
+
+/**
+ * Atomic update operation that renames a node.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Lukas Kircher
+ */
+final class Rename extends BasicUpdate {
+  /** Kind of updated node. */
+  private final int kind;
+  /** The new name of the node. */
+  private final byte[] name;
+  /** Name URI. */
+  private final byte[] uri;
+
+  /**
+   * Constructor.
+   * @param location PRE value of target node location
+   * @param kind target node kind
+   * @param name new name for the target node
+   * @param uri new name uri for the target node
+   * @param parent parent node PRE
+   */
+  private Rename(final int location, final int kind, final byte[] name, final byte[] uri,
+      final int parent) {
+    super(location, parent);
+    if(name.length == 0) throw Util.notExpected("New name must not be empty.");
+    this.kind = kind;
+    this.name = name;
+    this.uri = uri;
+  }
+
+  /**
+   * Factory.
+   * @param data data reference
+   * @param pre target node PRE
+   * @param name new name
+   * @param uri new uri
+   * @return instance
+   */
+  static Rename getInstance(final Data data, final int pre, final byte[] name, final byte[] uri) {
+    return new Rename(pre, data.kind(pre), name, uri, data.parent(pre, data.kind(pre)));
+  }
+
+  @Override
+  void apply(final Data data) {
+    data.update(location, kind, name, uri);
+  }
+
+  @Override
+  DataClip getInsertionData() {
+    throw Util.notExpected("No insertion sequence needed for atomic rename operation.");
+  }
+
+  @Override
+  boolean destructive() {
+    return false;
+  }
+
+  @Override
+  public String toString() {
+    return "\n Rename: " + super.toString();
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/up/atomic/Replace.java basex-8.2.3/basex-core/src/main/java/org/basex/query/up/atomic/Replace.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/up/atomic/Replace.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/up/atomic/Replace.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,150 @@
+package org.basex.query.up.atomic;
+
+import static org.basex.util.Token.*;
+
+import java.util.*;
+
+import org.basex.data.*;
+
+/**
+ * Replaces a node in the database with an insertion sequence.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Lukas Kircher
+ */
+final class Replace extends StructuralUpdate {
+  /** Insertion sequence. */
+  private final DataClip clip;
+
+  /**
+   * Constructor.
+   * @param location PRE value of the target node location
+   * @param clip insertion sequence data clip
+   * @param shifts PRE value shifts introduced by update
+   * @param acc accumulated shifts
+   * @param first PRE value of the first node which distance has to be updated
+   * @param parent parent node PRE
+   */
+  Replace(final int location, final int shifts, final int acc, final int first, final DataClip clip,
+      final int parent) {
+    super(location, shifts, acc, first, parent);
+    this.clip = clip;
+  }
+
+  /**
+   * Factory.
+   * @param data data reference
+   * @param pre target node PRE
+   * @param clip insertion sequence
+   * @return instance
+   */
+  static Replace getInstance(final Data data, final int pre, final DataClip clip) {
+    final int kind = data.kind(pre);
+    final int par = data.parent(pre, kind);
+    final int oldsize = data.size(pre, kind);
+    final int newsize = clip.size();
+    final int sh = newsize - oldsize;
+    return new Replace(pre, sh, sh, pre + oldsize, clip, par);
+  }
+
+  @Override
+  void apply(final Data data) {
+    // [LK] replace optimizations only work without namespaces..
+    if(data.nspaces.isEmpty() && clip.data.nspaces.isEmpty()) {
+      // Lazy Replace: rewrite to value updates if structure has not changed
+      if(lazyReplace(data)) return;
+      // Rapid Replace: in-place update, overwrite existing table entries
+      data.replace(location, clip);
+    } else {
+      // fallback: delete old entries, add new ones
+      final int kind = data.kind(location);
+      final int par = data.parent(location, kind);
+      // delete first - otherwise insert must be at location+1
+      data.delete(location);
+      if(kind == Data.ATTR) {
+        data.insertAttr(location, par, clip);
+      } else {
+        data.insert(location, par, clip);
+      }
+    }
+  }
+
+  /**
+   * Lazy Replace implementation. Checks if the replace operation can be substituted with
+   * cheaper value updates. If structural changes have to be made no substitution takes place.
+   * @param data destination data reference
+   * @return true if substitution successful
+   */
+  private boolean lazyReplace(final Data data) {
+    final Data src = clip.data;
+    final int srcSize = clip.size();
+    // check for equal subtree size
+    if(srcSize != data.size(location, data.kind(location))) return false;
+
+    final List<BasicUpdate> valueUpdates = new ArrayList<>();
+    for(int c = 0; c < srcSize; c++) {
+      final int s = clip.start + c;
+      final int t = location + c;
+      final int sk = src.kind(s);
+      final int tk = data.kind(t);
+
+      if(sk != tk)
+        return false;
+      // distance can differ for first two tuples
+      if(c > 0 && src.dist(s, sk) != data.dist(t, tk))
+        return false;
+      // check texts, comments and documents
+      if(sk == Data.TEXT || sk == Data.COMM || sk == Data.DOC) {
+        final byte[] srcText = src.text(s, true);
+        if(!eq(data.text(t, true), srcText))
+          valueUpdates.add(UpdateValue.getInstance(data, t, srcText));
+      } else {
+        // check elements, attributes and processing instructions
+        final byte[] srcName = src.name(s, sk);
+        final byte[] trgName = data.name(t, tk);
+        if(!eq(srcName, trgName)) valueUpdates.add(Rename.getInstance(data, t, srcName, EMPTY));
+        switch(sk) {
+          case Data.ELEM:
+            // check size of elements
+            if(src.attSize(s, sk) != data.attSize(t, tk) || src.size(s, sk) != data.size(t, tk))
+              return false;
+            break;
+          case Data.ATTR:
+            // check attribute values
+            final byte[] av = src.text(s, false);
+            if(!eq(data.text(t, false), av))
+              valueUpdates.add(UpdateValue.getInstance(data, t, av));
+            break;
+          case Data.PI:
+            // check processing instruction value
+            final byte[] srcText = src.text(s, true);
+            final byte[] trgText = data.text(t, true);
+            final int i = indexOf(srcText, ' ');
+            final byte[] pv = i == -1 ? EMPTY : substring(srcText, i + 1);
+            if(!eq(pv, indexOf(trgText, ' ') == -1 ? EMPTY :
+              substring(trgText, i + 1))) {
+              valueUpdates.add(UpdateValue.getInstance(data, t, pv));
+            }
+            break;
+        }
+      }
+    }
+    for(final BasicUpdate bu : valueUpdates) bu.apply(data);
+    return true;
+  }
+
+  @Override
+  DataClip getInsertionData() {
+    return clip;
+  }
+
+  @Override
+  boolean destructive() {
+    return true;
+  }
+
+  @Override
+  public String toString() {
+    return "\nReplace: " + super.toString();
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/up/atomic/StructuralUpdate.java basex-8.2.3/basex-core/src/main/java/org/basex/query/up/atomic/StructuralUpdate.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/up/atomic/StructuralUpdate.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/up/atomic/StructuralUpdate.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,48 @@
+package org.basex.query.up.atomic;
+
+/**
+ * Base class for structural updates that add to/remove from the table and introduce shifts.
+ * @author BaseX Team 2005-15, BSD License
+ * @author Lukas Kircher
+ */
+abstract class StructuralUpdate extends BasicUpdate {
+  /** PRE value shifts introduced by this atomic update due to structural changes. */
+  final int shifts;
+  /** PRE value of the first node for which the distance must be updated due to PRE value
+   * shifts introduced by this update. */
+  final int preOfAffectedNode;
+  /** Total/accumulated number of shifts introduced by all updates on the list up to this
+   * update (inclusive). The number of total shifts is used to calculate PRE values
+   * before/after updates. */
+  int accumulatedShifts;
+
+  /**
+   * Constructor.
+   * @param location target node location PRE
+   * @param shifts PRE value shifts introduced by update
+   * @param acc accumulated shifts
+   * @param first PRE value of the first node the distance of which has to be updated
+   * @param parent parent node
+   */
+  StructuralUpdate(final int location, final int shifts, final int acc, final int first,
+      final int parent) {
+    super(location, parent);
+    this.shifts = shifts;
+    accumulatedShifts = acc;
+    preOfAffectedNode = first;
+  }
+
+  @Override
+  int accumulatedShifts() {
+    return accumulatedShifts;
+  }
+
+  @Override
+  public String toString() {
+    return "L" + location +
+        " PAR" + parent +
+        " SHF" + shifts +
+        " ASHF" + accumulatedShifts +
+        " AFF" + preOfAffectedNode;
+  }
+}
\ No newline at end of file
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/up/atomic/UpdateValue.java basex-8.2.3/basex-core/src/main/java/org/basex/query/up/atomic/UpdateValue.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/up/atomic/UpdateValue.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/up/atomic/UpdateValue.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,62 @@
+package org.basex.query.up.atomic;
+
+import org.basex.data.*;
+import org.basex.util.*;
+
+/**
+ * Atomic update operation that replaces the value of a single text, comment, pi or
+ * attribute node.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Lukas Kircher
+ */
+final class UpdateValue extends BasicUpdate {
+  /** Target node kind. */
+  private final int kind;
+  /** New value for target node. */
+  private final byte[] value;
+
+  /**
+   * Constructor.
+   * @param location PRE value of the target node location
+   * @param kind node kind of the target node
+   * @param value new value which is assigned to the target node
+   * @param parent parent of updated node
+   */
+  private UpdateValue(final int location, final int kind, final byte[] value, final int parent) {
+    super(location, parent);
+    this.kind = kind;
+    this.value = value;
+  }
+
+  /**
+   * Factory.
+   * @param data data reference
+   * @param pre PRE value of the target node location
+   * @param value new value which is assigned to the target node
+   * @return new instance
+   */
+  static UpdateValue getInstance(final Data data, final int pre, final byte[] value) {
+    return new UpdateValue(pre, data.kind(pre), value, data.parent(pre, data.kind(pre)));
+  }
+
+  @Override
+  void apply(final Data data) {
+    data.update(location, kind, value);
+  }
+
+  @Override
+  DataClip getInsertionData() {
+    throw Util.notExpected("No insertion sequence needed for atomic value update operation.");
+  }
+
+  @Override
+  boolean destructive() {
+    return false;
+  }
+
+  @Override
+  public String toString() {
+    return "\nUpdateValue: " + super.toString();
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/up/DataUpdates.java basex-8.2.3/basex-core/src/main/java/org/basex/query/up/DataUpdates.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/up/DataUpdates.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/up/DataUpdates.java	2015-07-14 10:54:40.000000000 +0000
@@ -9,9 +9,9 @@
 import org.basex.core.*;
 import org.basex.core.cmd.*;
 import org.basex.data.*;
-import org.basex.data.atomic.*;
 import org.basex.query.*;
 import org.basex.query.func.fn.*;
+import org.basex.query.up.atomic.*;
 import org.basex.query.up.primitives.*;
 import org.basex.query.up.primitives.db.*;
 import org.basex.query.up.primitives.node.*;
@@ -279,8 +279,8 @@
       if(data.kind(pre) == Data.ATTR) {
         final byte[] nm = data.name(pre, Data.ATTR);
         final QNm name = new QNm(nm);
-        final byte[] uri = data.nspaces.uri(data.nspaces.uri(nm, pre, data));
-        if(uri != null) name.uri(uri);
+        final int uriId = data.nspaces.uriIdForPrefix(Token.prefix(nm), pre, data);
+        if(uriId != 0) name.uri(data.nspaces.uri(uriId));
         pool.add(name, NodeType.ATT);
         il.add(pre);
       } else {
@@ -289,8 +289,8 @@
           final byte[] nm = data.name(p, Data.ATTR);
           if(!il.contains(p)) {
             final QNm name = new QNm(nm);
-            final byte[] uri = data.nspaces.uri(data.nspaces.uri(nm, p, data));
-            if(uri != null) name.uri(uri);
+            final int uriId = data.nspaces.uriIdForPrefix(Token.prefix(nm), p, data);
+            if(uriId != 0) name.uri(data.nspaces.uri(uriId));
             pool.add(name, NodeType.ATT);
           }
         }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/up/expr/Delete.java basex-8.2.3/basex-core/src/main/java/org/basex/query/up/expr/Delete.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/up/expr/Delete.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/up/expr/Delete.java	2015-07-14 10:54:40.000000000 +0000
@@ -41,7 +41,7 @@
       if(n.parent() == null) continue;
       final Updates updates = qc.resources.updates();
       final DBNode dbn = updates.determineDataRef(n, qc);
-      updates.add(new DeleteNode(dbn.pre, dbn.data, info), qc);
+      updates.add(new DeleteNode(dbn.pre(), dbn.data(), info), qc);
     }
     return null;
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/up/expr/Insert.java basex-8.2.3/basex-core/src/main/java/org/basex/query/up/expr/Insert.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/up/expr/Insert.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/up/expr/Insert.java	2015-07-14 10:54:40.000000000 +0000
@@ -88,18 +88,18 @@
       if(targ.type != NodeType.ELM) throw (before || after ? UPATTELM : UPATTELM2).get(info);
 
       dbn = updates.determineDataRef(targ, qc);
-      up = new InsertAttribute(dbn.pre, dbn.data, info, checkNS(aList, targ));
+      up = new InsertAttribute(dbn.pre(), dbn.data(), info, checkNS(aList, targ));
       updates.add(up, qc);
     }
 
     // no update primitive is created if node list is empty
     if(!cList.isEmpty()) {
       dbn = updates.determineDataRef(n, qc);
-      if(before) up = new InsertBefore(dbn.pre, dbn.data, info, cList);
-      else if(after) up = new InsertAfter(dbn.pre, dbn.data, info, cList);
-      else if(first) up = new InsertIntoAsFirst(dbn.pre, dbn.data, info, cList);
-      else if(last) up = new InsertIntoAsLast(dbn.pre, dbn.data, info, cList);
-      else up = new InsertInto(dbn.pre, dbn.data, info, cList);
+      if(before) up = new InsertBefore(dbn.pre(), dbn.data(), info, cList);
+      else if(after) up = new InsertAfter(dbn.pre(), dbn.data(), info, cList);
+      else if(first) up = new InsertIntoAsFirst(dbn.pre(), dbn.data(), info, cList);
+      else if(last) up = new InsertIntoAsLast(dbn.pre(), dbn.data(), info, cList);
+      else up = new InsertInto(dbn.pre(), dbn.data(), info, cList);
       updates.add(up, qc);
     }
     return null;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/up/expr/Modify.java basex-8.2.3/basex-core/src/main/java/org/basex/query/up/expr/Modify.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/up/expr/Modify.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/up/expr/Modify.java	2015-07-14 10:54:40.000000000 +0000
@@ -57,7 +57,7 @@
 
   @Override
   public Value value(final QueryContext qc) throws QueryException {
-    final int o = (int) qc.resources.output.size();
+    final int o = qc.resources.output.size();
     final Updates updates = qc.resources.updates();
     final ContextModifier tmp = updates.mod;
     final TransformModifier pu = new TransformModifier();
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/up/expr/Rename.java basex-8.2.3/basex-core/src/main/java/org/basex/query/up/expr/Rename.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/up/expr/Rename.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/up/expr/Rename.java	2015-07-14 10:54:40.000000000 +0000
@@ -72,7 +72,7 @@
 
     final Updates updates = qc.resources.updates();
     final DBNode dbn = updates.determineDataRef(targ, qc);
-    updates.add(new RenameNode(dbn.pre, dbn.data, info, rename), qc);
+    updates.add(new RenameNode(dbn.pre(), dbn.data(), info, rename), qc);
     return null;
   }
 
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/up/expr/Replace.java basex-8.2.3/basex-core/src/main/java/org/basex/query/up/expr/Replace.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/up/expr/Replace.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/up/expr/Replace.java	2015-07-14 10:54:40.000000000 +0000
@@ -70,7 +70,7 @@
       if(tp == NodeType.COM) FComm.parse(txt, info);
       if(tp == NodeType.PI) FPI.parse(txt, info);
 
-      updates.add(new ReplaceValue(dbn.pre, dbn.data, info, txt), qc);
+      updates.add(new ReplaceValue(dbn.pre(), dbn.data(), info, txt), qc);
     } else {
       final ANode par = targ.parent();
       if(par == null) throw UPNOPAR_X.get(info, i);
@@ -83,7 +83,7 @@
         if(!aList.isEmpty()) throw UPWRELM.get(info);
       }
       // conforms to specification: insertion sequence may be empty
-      updates.add(new ReplaceNode(dbn.pre, dbn.data, info, list), qc);
+      updates.add(new ReplaceNode(dbn.pre(), dbn.data(), info, list), qc);
     }
     return null;
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/up/expr/Transform.java basex-8.2.3/basex-core/src/main/java/org/basex/query/up/expr/Transform.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/up/expr/Transform.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/up/expr/Transform.java	2015-07-14 10:54:40.000000000 +0000
@@ -61,7 +61,7 @@
 
   @Override
   public Value value(final QueryContext qc) throws QueryException {
-    final int o = (int) qc.resources.output.size();
+    final int o = qc.resources.output.size();
     final Updates updates = qc.resources.updates();
     final ContextModifier tmp = updates.mod;
     final TransformModifier pu = new TransformModifier();
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/up/primitives/db/DBAdd.java basex-8.2.3/basex-core/src/main/java/org/basex/query/up/primitives/db/DBAdd.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/up/primitives/db/DBAdd.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/up/primitives/db/DBAdd.java	2015-07-14 10:54:40.000000000 +0000
@@ -3,7 +3,6 @@
 import java.util.*;
 
 import org.basex.data.*;
-import org.basex.data.atomic.*;
 import org.basex.query.*;
 import org.basex.query.up.primitives.*;
 import org.basex.util.*;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/up/primitives/db/Put.java basex-8.2.3/basex-core/src/main/java/org/basex/query/up/primitives/db/Put.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/up/primitives/db/Put.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/up/primitives/db/Put.java	2015-07-14 10:54:40.000000000 +0000
@@ -49,7 +49,7 @@
       final DBNode node = new DBNode(data, pre);
       try(final PrintOutput po = new PrintOutput(u)) {
         // try to reproduce non-chopped documents correctly
-        final SerializerOptions so = SerializerOptions.get(node.data.meta.chop);
+        final SerializerOptions so = SerializerOptions.get(node.data().meta.chop);
         try(final Serializer ser = Serializer.get(po, so)) {
           ser.serialize(node);
         }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/up/primitives/DBNew.java basex-8.2.3/basex-core/src/main/java/org/basex/query/up/primitives/DBNew.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/up/primitives/DBNew.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/up/primitives/DBNew.java	2015-07-14 10:54:40.000000000 +0000
@@ -9,7 +9,6 @@
 import org.basex.build.*;
 import org.basex.core.*;
 import org.basex.data.*;
-import org.basex.data.atomic.*;
 import org.basex.io.*;
 import org.basex.query.*;
 import org.basex.util.*;
@@ -92,7 +91,7 @@
     // add document node
     final Context ctx = qc.context;
     if(ni.node != null) {
-      final MemData mdata = (MemData) ni.node.dbCopy(options).data;
+      final MemData mdata = (MemData) ni.node.dbCopy(options).data();
       mdata.update(0, Data.DOC, ni.path);
       return new DataClip(mdata);
     }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/up/primitives/name/DBCreate.java basex-8.2.3/basex-core/src/main/java/org/basex/query/up/primitives/name/DBCreate.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/up/primitives/name/DBCreate.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/up/primitives/name/DBCreate.java	2015-07-14 10:54:40.000000000 +0000
@@ -10,7 +10,6 @@
 import org.basex.core.*;
 import org.basex.core.cmd.*;
 import org.basex.data.*;
-import org.basex.data.atomic.*;
 import org.basex.query.*;
 import org.basex.query.func.*;
 import org.basex.query.up.primitives.*;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/up/primitives/node/DeleteNode.java basex-8.2.3/basex-core/src/main/java/org/basex/query/up/primitives/node/DeleteNode.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/up/primitives/node/DeleteNode.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/up/primitives/node/DeleteNode.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,8 +1,8 @@
 package org.basex.query.up.primitives.node;
 
 import org.basex.data.*;
-import org.basex.data.atomic.*;
 import org.basex.query.up.*;
+import org.basex.query.up.atomic.*;
 import org.basex.query.up.primitives.*;
 import org.basex.query.value.node.*;
 import org.basex.util.*;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/up/primitives/node/InsertAfter.java basex-8.2.3/basex-core/src/main/java/org/basex/query/up/primitives/node/InsertAfter.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/up/primitives/node/InsertAfter.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/up/primitives/node/InsertAfter.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,8 +1,8 @@
 package org.basex.query.up.primitives.node;
 
 import org.basex.data.*;
-import org.basex.data.atomic.*;
 import org.basex.query.up.*;
+import org.basex.query.up.atomic.*;
 import org.basex.query.up.primitives.*;
 import org.basex.query.util.list.*;
 import org.basex.query.value.node.*;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/up/primitives/node/InsertAttribute.java basex-8.2.3/basex-core/src/main/java/org/basex/query/up/primitives/node/InsertAttribute.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/up/primitives/node/InsertAttribute.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/up/primitives/node/InsertAttribute.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,8 +1,8 @@
 package org.basex.query.up.primitives.node;
 
 import org.basex.data.*;
-import org.basex.data.atomic.*;
 import org.basex.query.up.*;
+import org.basex.query.up.atomic.*;
 import org.basex.query.up.primitives.*;
 import org.basex.query.util.list.*;
 import org.basex.query.value.node.*;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/up/primitives/node/InsertBefore.java basex-8.2.3/basex-core/src/main/java/org/basex/query/up/primitives/node/InsertBefore.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/up/primitives/node/InsertBefore.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/up/primitives/node/InsertBefore.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,8 +1,8 @@
 package org.basex.query.up.primitives.node;
 
 import org.basex.data.*;
-import org.basex.data.atomic.*;
 import org.basex.query.up.*;
+import org.basex.query.up.atomic.*;
 import org.basex.query.up.primitives.*;
 import org.basex.query.util.list.*;
 import org.basex.query.value.node.*;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/up/primitives/node/InsertIntoAsFirst.java basex-8.2.3/basex-core/src/main/java/org/basex/query/up/primitives/node/InsertIntoAsFirst.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/up/primitives/node/InsertIntoAsFirst.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/up/primitives/node/InsertIntoAsFirst.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,8 +1,8 @@
 package org.basex.query.up.primitives.node;
 
 import org.basex.data.*;
-import org.basex.data.atomic.*;
 import org.basex.query.up.*;
+import org.basex.query.up.atomic.*;
 import org.basex.query.up.primitives.*;
 import org.basex.query.util.list.*;
 import org.basex.query.value.node.*;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/up/primitives/node/InsertIntoAsLast.java basex-8.2.3/basex-core/src/main/java/org/basex/query/up/primitives/node/InsertIntoAsLast.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/up/primitives/node/InsertIntoAsLast.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/up/primitives/node/InsertIntoAsLast.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,8 +1,8 @@
 package org.basex.query.up.primitives.node;
 
 import org.basex.data.*;
-import org.basex.data.atomic.*;
 import org.basex.query.up.*;
+import org.basex.query.up.atomic.*;
 import org.basex.query.up.primitives.*;
 import org.basex.query.util.list.*;
 import org.basex.query.value.node.*;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/up/primitives/node/InsertInto.java basex-8.2.3/basex-core/src/main/java/org/basex/query/up/primitives/node/InsertInto.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/up/primitives/node/InsertInto.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/up/primitives/node/InsertInto.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,8 +1,8 @@
 package org.basex.query.up.primitives.node;
 
 import org.basex.data.*;
-import org.basex.data.atomic.*;
 import org.basex.query.up.*;
+import org.basex.query.up.atomic.*;
 import org.basex.query.up.primitives.*;
 import org.basex.query.util.list.*;
 import org.basex.query.value.node.*;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/up/primitives/node/NodeCopy.java basex-8.2.3/basex-core/src/main/java/org/basex/query/up/primitives/node/NodeCopy.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/up/primitives/node/NodeCopy.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/up/primitives/node/NodeCopy.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,7 +1,6 @@
 package org.basex.query.up.primitives.node;
 
 import org.basex.data.*;
-import org.basex.data.atomic.*;
 import org.basex.query.up.*;
 import org.basex.query.up.primitives.*;
 import org.basex.query.util.*;
@@ -46,8 +45,7 @@
     // build main memory representation of nodes to be copied
     final int start = tmp.meta.size;
     new DataBuilder(tmp).build(list);
-    insseq = new DataClip(tmp, start, tmp.meta.size);
-    insseq.fragments = list.size();
+    insseq = new DataClip(tmp, start, tmp.meta.size, list.size());
   }
 
   /**
@@ -57,16 +55,15 @@
    */
   final void add(final NamePool pool) {
     final Data d = insseq.data;
-    final int ps = insseq.start;
-    final int pe = insseq.end;
-    for(int p = ps; p < pe; ++p) {
-      final int k = d.kind(p);
-      if(k != Data.ATTR && k != Data.ELEM) continue;
-      if(p > ps && d.parent(p, k) >= ps) break;
-      final int u = d.uri(p, k);
-      final QNm qnm = new QNm(d.name(p, k));
-      if(u != 0) qnm.uri(d.nspaces.uri(u));
-      pool.add(qnm, ANode.type(k));
+    final int s = insseq.start, e = insseq.end;
+    for(int p = s; p < e; ++p) {
+      final int kind = d.kind(p);
+      if(kind != Data.ATTR && kind != Data.ELEM) continue;
+      if(p > s && d.parent(p, kind) >= s) break;
+      final int uriId = d.uriId(p, kind);
+      final QNm qnm = new QNm(d.name(p, kind));
+      if(uriId != 0) qnm.uri(d.nspaces.uri(uriId));
+      pool.add(qnm, ANode.type(kind));
     }
   }
 
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/up/primitives/node/NodeUpdate.java basex-8.2.3/basex-core/src/main/java/org/basex/query/up/primitives/node/NodeUpdate.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/up/primitives/node/NodeUpdate.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/up/primitives/node/NodeUpdate.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,9 +1,9 @@
 package org.basex.query.up.primitives.node;
 
 import org.basex.data.*;
-import org.basex.data.atomic.*;
 import org.basex.query.*;
 import org.basex.query.up.*;
+import org.basex.query.up.atomic.*;
 import org.basex.query.up.primitives.*;
 import org.basex.query.value.node.*;
 import org.basex.util.*;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/up/primitives/node/RenameNode.java basex-8.2.3/basex-core/src/main/java/org/basex/query/up/primitives/node/RenameNode.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/up/primitives/node/RenameNode.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/up/primitives/node/RenameNode.java	2015-07-14 10:54:40.000000000 +0000
@@ -3,9 +3,9 @@
 import static org.basex.query.QueryError.*;
 
 import org.basex.data.*;
-import org.basex.data.atomic.*;
 import org.basex.query.*;
 import org.basex.query.up.*;
+import org.basex.query.up.atomic.*;
 import org.basex.query.up.primitives.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.node.*;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/up/primitives/node/ReplaceDoc.java basex-8.2.3/basex-core/src/main/java/org/basex/query/up/primitives/node/ReplaceDoc.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/up/primitives/node/ReplaceDoc.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/up/primitives/node/ReplaceDoc.java	2015-07-14 10:54:40.000000000 +0000
@@ -5,9 +5,9 @@
 import java.util.*;
 
 import org.basex.data.*;
-import org.basex.data.atomic.*;
 import org.basex.query.*;
 import org.basex.query.up.*;
+import org.basex.query.up.atomic.*;
 import org.basex.query.up.primitives.*;
 import org.basex.util.*;
 import org.basex.util.options.*;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/up/primitives/node/ReplaceNode.java basex-8.2.3/basex-core/src/main/java/org/basex/query/up/primitives/node/ReplaceNode.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/up/primitives/node/ReplaceNode.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/up/primitives/node/ReplaceNode.java	2015-07-14 10:54:40.000000000 +0000
@@ -3,9 +3,9 @@
 import static org.basex.query.QueryError.*;
 
 import org.basex.data.*;
-import org.basex.data.atomic.*;
 import org.basex.query.*;
 import org.basex.query.up.*;
+import org.basex.query.up.atomic.*;
 import org.basex.query.up.primitives.*;
 import org.basex.query.util.list.*;
 import org.basex.util.*;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/up/primitives/node/ReplaceValue.java basex-8.2.3/basex-core/src/main/java/org/basex/query/up/primitives/node/ReplaceValue.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/up/primitives/node/ReplaceValue.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/up/primitives/node/ReplaceValue.java	2015-07-14 10:54:40.000000000 +0000
@@ -5,9 +5,9 @@
 import java.util.*;
 
 import org.basex.data.*;
-import org.basex.data.atomic.*;
 import org.basex.query.*;
 import org.basex.query.up.*;
+import org.basex.query.up.atomic.*;
 import org.basex.query.up.primitives.*;
 import org.basex.query.util.list.*;
 import org.basex.query.value.node.*;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/up/primitives/UserUpdate.java basex-8.2.3/basex-core/src/main/java/org/basex/query/up/primitives/UserUpdate.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/up/primitives/UserUpdate.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/up/primitives/UserUpdate.java	2015-07-14 10:54:40.000000000 +0000
@@ -65,7 +65,7 @@
   public final void merge(final Update update) throws QueryException {
     final String db = ((UserUpdate) update).patterns.get(0);
     if(patterns.contains(db)) {
-      if(db == null) throw USER_UPDATE_X_X.get(info, name(), operation());
+      if(db.isEmpty()) throw USER_UPDATE_X_X.get(info, name(), operation());
       throw USER_UPDATE_X_X_X.get(info, db, name(), operation());
     }
     patterns.add(db);
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/up/Updates.java basex-8.2.3/basex-core/src/main/java/org/basex/query/up/Updates.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/up/Updates.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/up/Updates.java	2015-07-14 10:54:40.000000000 +0000
@@ -3,9 +3,9 @@
 import java.util.*;
 
 import org.basex.data.*;
-import org.basex.data.atomic.*;
 import org.basex.query.*;
 import org.basex.query.iter.*;
+import org.basex.query.up.atomic.*;
 import org.basex.query.up.primitives.*;
 import org.basex.query.up.primitives.node.*;
 import org.basex.query.value.node.*;
@@ -93,7 +93,7 @@
 
     // determine highest ancestor node
     ANode anc = target;
-    final AxisIter it = target.ancestor();
+    final BasicNodeIter it = target.ancestor();
     for(ANode p; (p = it.next()) != null;) anc = p;
 
     /* See if this ancestor has already been added to the pending update list.
@@ -103,7 +103,7 @@
     MemData data = fragmentIDs.get(ancID);
     // if data doesn't exist, create a new one
     if(data == null) {
-      data = (MemData) anc.dbCopy(qc.context.options).data;
+      data = (MemData) anc.dbCopy(qc.context.options).data();
       // create a mapping between the fragment id and the data reference
       fragmentIDs.put(ancID, data);
     }
@@ -163,7 +163,7 @@
     if(node.id == trgID) return 0;
 
     int s = 1;
-    AxisIter it = node.attributes();
+    BasicNodeIter it = node.attributes();
     for(ANode n; (n = it.next()) != null;) {
       final int st = preSteps(n, trgID);
       if(st == 0) return s;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/Ann.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/Ann.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/Ann.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/Ann.java	2015-07-14 10:54:40.000000000 +0000
@@ -15,8 +15,10 @@
 public final class Ann {
   /** Input info. */
   public final InputInfo info;
-  /** Annotation signature. */
+  /** Annotation signature (is {@code null} if {@link #name} is assigned). */
   public final Annotation sig;
+  /** No-standard annotation (is {@code null} if {@link #sig} is assigned). */
+  public final QNm name;
   /** Arguments. */
   public final Item[] args;
 
@@ -28,27 +30,43 @@
    */
   public Ann(final InputInfo info, final Annotation sig, final Item... args) {
     this.info = info;
+    this.args = args;
     this.sig = sig;
+    this.name = null;
+  }
+
+  /**
+   * Constructor.
+   * @param info input info
+   * @param name name of annotation
+   * @param args arguments
+   */
+  public Ann(final InputInfo info, final QNm name, final Item... args) {
+    this.info = info;
     this.args = args;
+    this.name = name;
+    this.sig = null;
   }
 
   /**
    * Compares two annotations.
-   * @param an annotation to be compared
+   * @param ann annotation to be compared
    * @return result of check
    */
-  public boolean eq(final Ann an) {
+  public boolean eq(final Ann ann) {
     final long as = args.length;
-    if(sig != an.sig || as != an.args.length) return false;
+    if(sig != null ? (sig != ann.sig) : (ann.name == null || !name.eq(ann.name))) return false;
+    if(as != ann.args.length) return false;
     for(int a = 0; a < as; a++) {
-      if(!args[a].sameAs(an.args[a])) return false;
+      if(!args[a].sameAs(ann.args[a])) return false;
     }
     return true;
   }
 
   @Override
   public String toString() {
-    final TokenBuilder tb = new TokenBuilder().add('%').add(sig.id());
+    final TokenBuilder tb = new TokenBuilder().add('%');
+    tb.add(sig == null ? name.prefixId(XQ_URI) : sig.id());
     if(args.length != 0) tb.add('(').addSep(args, SEP).add(')');
     return tb.add(' ').toString();
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/collation/CollationItemSet.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/collation/CollationItemSet.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/collation/CollationItemSet.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/collation/CollationItemSet.java	2015-07-14 10:54:40.000000000 +0000
@@ -3,8 +3,8 @@
 import java.util.*;
 
 import org.basex.query.*;
-import org.basex.query.iter.*;
 import org.basex.query.util.hash.*;
+import org.basex.query.util.list.*;
 import org.basex.query.value.item.*;
 import org.basex.util.*;
 
@@ -16,7 +16,7 @@
  */
 public final class CollationItemSet implements ItemSet {
   /** Items. */
-  private final ValueBuilder items = new ValueBuilder();
+  private final ItemList items = new ItemList();
   /** Collation. */
   private final Collation coll;
 
@@ -30,7 +30,7 @@
 
   @Override
   public boolean add(final Item item, final InputInfo ii) throws QueryException {
-    final int is = (int) items.size();
+    final int is = items.size();
     for(int id = 0; id < is; id++) {
       if(items.get(id).equiv(item, coll, ii)) return false;
     }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/DataBuilder.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/DataBuilder.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/DataBuilder.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/DataBuilder.java	2015-07-14 10:54:40.000000000 +0000
@@ -8,6 +8,7 @@
 import org.basex.data.*;
 import org.basex.query.iter.*;
 import org.basex.query.util.DataFTBuilder.DataFTMarker;
+import org.basex.query.util.ft.*;
 import org.basex.query.util.list.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.node.*;
@@ -15,7 +16,7 @@
 import org.basex.util.*;
 
 /**
- * Class for building memory-based database nodes.
+ * Data builder. Provides methods for copying XML nodes into a main-memory database instance.
  *
  * @author BaseX Team 2005-15, BSD License
  * @author Christian Gruen
@@ -23,10 +24,8 @@
 public final class DataBuilder {
   /** Target data instance. */
   private final MemData data;
-  /** Full-text position data. */
+  /** Full-text result builder. */
   private DataFTBuilder ftbuilder;
-  /** Index reference of marker element. */
-  private int name;
 
   /**
    * Constructor.
@@ -44,13 +43,12 @@
    * @return self reference
    */
   public DataBuilder ftpos(final byte[] nm, final FTPosData pos, final int len) {
-    ftbuilder = new DataFTBuilder(pos, len);
-    name = data.elemNames.index(nm, null, false);
+    ftbuilder = new DataFTBuilder(pos, len, data.elemNames.index(nm, null, false));
     return this;
   }
 
   /**
-   * Fills the data instance with the specified node.
+   * Adds database entries for the specified node.
    * @param node node
    */
   public void build(final ANode node) {
@@ -58,29 +56,27 @@
   }
 
   /**
-   * Fills the data instance with the specified nodes.
+   * Adds database entries for the specified nodes.
    * @param nodes node list
    */
   public void build(final ANodeList nodes) {
     data.meta.update();
-    int ds = data.meta.size;
-    for(final ANode n : nodes) ds = addNode(n, ds, -1, null);
+    int next = data.meta.size;
+    for(final ANode n : nodes) next = addNode(n, next, -1);
   }
 
   /**
-   * Adds a fragment to a database instance.
-   * Document nodes are ignored.
+   * Adds a node.
    * @param node node to be added
    * @param pre node position
    * @param par node parent
-   * @param pNode parent of node to be added
    * @return pre value of next node
    */
-  private int addNode(final ANode node, final int pre, final int par, final ANode pNode) {
+  private int addNode(final ANode node, final int pre, final int par) {
     switch(node.nodeType()) {
       case DOC: return addDoc(node, pre);
       case ELM: return addElem(node, pre, par);
-      case TXT: return addText(node, pre, par, pNode);
+      case TXT: return addText(node, pre, par);
       case ATT: return addAttr(node, pre, par);
       case COM: return addComm(node, pre, par);
       // will always be processing instruction
@@ -95,15 +91,14 @@
    * @return pre value of next node
    */
   private int addDoc(final ANode node, final int pre) {
-    final int ds = data.meta.size;
-    final int s = size(node, false);
-    data.doc(ds, s, node.baseURI());
-    data.insert(ds);
-    int p = pre + 1;
-    final AxisIter ai = node.children();
-    for(ANode ch; (ch = ai.next()) != null;) p = addNode(ch, p, pre, null);
-    if(s != p - pre) data.size(ds, Data.DOC, p - pre);
-    return p;
+    final int last = data.meta.size;
+    final int size = size(node, false);
+    data.doc(last, size, node.baseURI());
+    data.insert(last);
+    int next = pre + 1;
+    for(final ANode child : node.children()) next = addNode(child, next, pre);
+    if(size != next - pre) data.size(last, Data.DOC, next - pre);
+    return next;
   }
 
   /**
@@ -111,22 +106,19 @@
    * @param node node to be added
    * @param pre pre reference
    * @param par parent reference
-   * @return number of added nodes
+   * @return pre value of next node
    */
   private int addAttr(final ANode node, final int pre, final int par) {
-    final int ds = data.meta.size;
-    final QNm q = node.qname();
-    final byte[] uri = q.uri();
-    int u = 0;
-    if(uri.length != 0) {
-      if(par == -1) data.nspaces.add(ds, pre + 1, q.prefix(), uri, data);
-      u = data.nspaces.uri(uri);
-    }
-    final int n = data.attrNames.index(q.string(), null, false);
-    // usually, attributes don't have a namespace flag.
-    // this is different here, because a stand-alone attribute has no parent element.
-    data.attr(ds, pre - par, n, node.string(), u, par == -1 && u != 0);
-    data.insert(ds);
+    final int last = data.meta.size;
+    final QNm qname = node.qname();
+    final byte[] prefix = qname.prefix(), uri = qname.uri();
+    // create new namespace entry if this is a prefixed and standalone attribute
+    final int uriId = uri.length == 0 || eq(prefix, XML) ? 0 :
+      par != -1 ? data.nspaces.uriId(uri) : data.nspaces.add(last, prefix, uri, data);
+
+    final int nameId = data.attrNames.index(qname.string(), null, false);
+    data.attr(last, pre - par, nameId, node.string(), uriId);
+    data.insert(last);
     return pre + 1;
   }
 
@@ -135,29 +127,24 @@
    * @param node node to be added
    * @param pre pre reference
    * @param par parent reference
-   * @param pNode parent node
    * @return pre value of next node
    */
-  private int addText(final ANode node, final int pre, final int par, final ANode pNode) {
+  private int addText(final ANode node, final int pre, final int par) {
     // check full-text mode
     int dist = pre - par;
     final ArrayList<DataFTMarker> marks = ftbuilder != null ? ftbuilder.build(node) : null;
-    if(marks == null) return pre + addText(node.string(), dist);
-
-    // adopt namespace from parent
-    ANode p = pNode;
-    while(p != null) {
-      final QNm n = p.qname();
-      if(n != null && !n.hasPrefix()) break;
-      p = p.parent();
+    if(marks == null) {
+      addText(node.string(), dist);
+      return pre + 1;
     }
-    final int u = p == null ? 0 : data.nspaces.uri(p.name(), true);
 
+    // adopt namespace from ancestor
+    final int uriId = data.nspaces.uriIdForPrefix(EMPTY, true);
     int ts = marks.size();
     for(final DataFTMarker marker : marks) {
       if(marker.mark) {
         // open element
-        data.elem(dist++, name, 1, 2, u, false);
+        data.elem(dist++, ftbuilder.name(), 1, 2, uriId, false);
         data.insert(data.meta.size);
         ts++;
       }
@@ -171,13 +158,11 @@
    * Adds a text.
    * @param text text node
    * @param dist distance
-   * @return number of added nodes
    */
-  private int addText(final byte[] text, final int dist) {
-    final int ds = data.meta.size;
-    data.text(ds, dist, text, Data.TEXT);
-    data.insert(ds);
-    return 1;
+  private void addText(final byte[] text, final int dist) {
+    final int last = data.meta.size;
+    data.text(last, dist, text, Data.TEXT);
+    data.insert(last);
   }
 
   /**
@@ -185,13 +170,13 @@
    * @param node node to be added
    * @param pre pre reference
    * @param par parent reference
-   * @return number of added nodes
+   * @return pre value of next node
    */
   private int addPI(final ANode node, final int pre, final int par) {
-    final int ds = data.meta.size;
-    final byte[] v = trim(concat(node.name(), SPACE, node.string()));
-    data.text(ds, pre - par, v, Data.PI);
-    data.insert(ds);
+    final int last = data.meta.size;
+    final byte[] value = trim(concat(node.name(), SPACE, node.string()));
+    data.text(last, pre - par, value, Data.PI);
+    data.insert(last);
     return pre + 1;
   }
 
@@ -200,12 +185,12 @@
    * @param node node to be added
    * @param pre pre reference
    * @param par parent reference
-   * @return number of added nodes
+   * @return pre value of next node
    */
   private int addComm(final ANode node, final int pre, final int par) {
-    final int ds = data.meta.size;
-    data.text(ds, pre - par, node.string(), Data.COMM);
-    data.insert(ds);
+    final int last = data.meta.size;
+    data.text(last, pre - par, node.string(), Data.COMM);
+    data.insert(last);
     return pre + 1;
   }
 
@@ -217,58 +202,57 @@
    * @return pre value of next node
    */
   private int addElem(final ANode node, final int pre, final int par) {
-    final int ds = data.meta.size;
+    final int last = data.meta.size;
 
     // add new namespaces
-    data.nspaces.prepare();
     final Atts ns = par == -1 ? node.nsScope(null) : node.namespaces();
-    final int nl = ns.size();
-    for(int n = 0; n < nl; n++) data.nspaces.add(ns.name(n), ns.value(n), ds);
+    data.nspaces.open(last, ns);
 
-    // analyze node name
-    final QNm nm = node.qname();
-    final int tn = data.elemNames.index(nm.string(), null, false);
-    final int s = size(node, false);
-    final int u = data.nspaces.uri(nm.uri());
+    // collect node name properties
+    final QNm qname = node.qname();
+    final int size = size(node, false), asize = size(node, true);
+    final int nameId = data.elemNames.index(qname.string(), null, false);
+    final int uriId = data.nspaces.uriId(qname.uri());
 
     // add element node
-    data.elem(pre - par, tn, size(node, true), s, u, nl != 0);
-    data.insert(ds);
+    data.elem(pre - par, nameId, asize, size, uriId, !ns.isEmpty());
+    data.insert(last);
+
+    // add attributes and child nodes
+    int cPre = pre + 1;
+    for(final ANode attr : node.attributes()) cPre = addAttr(attr, cPre, pre);
+    for(final ANode child : node.children()) cPre = addNode(child, cPre, pre);
 
-    // add attributes and children
-    int p = pre + 1;
-    AxisIter ai = node.attributes();
-    for(ANode ch; (ch = ai.next()) != null;) p = addAttr(ch, p, pre);
-    ai = node.children();
-    for(ANode ch; (ch = ai.next()) != null;) p = addNode(ch, p, pre, node);
-    data.nspaces.close(ds);
+    // finalize namespace structure
+    data.nspaces.close(last);
 
     // update size if additional nodes have been added by the descendants
-    if(s != p - pre) data.size(ds, Data.ELEM, p - pre);
-    return p;
+    if(size != cPre - pre) data.size(last, Data.ELEM, cPre - pre);
+    return cPre;
   }
 
   /**
-   * Determines the number of descendants of a fragment.
+   * Returns the number of descendants of a fragment, including the node itself.
    * @param node fragment node
    * @param att count attributes instead of elements
    * @return number of descendants + 1 or attribute size + 1
    */
   private static int size(final ANode node, final boolean att) {
     if(node instanceof DBNode) {
-      final DBNode dbn = (DBNode) node;
-      final int k = node.kind();
-      return att ? dbn.data.attSize(dbn.pre, k) : dbn.data.size(dbn.pre, k);
+      final DBNode dbnode = (DBNode) node;
+      final Data data = dbnode.data();
+      final int kind = node.kind();
+      final int pre = dbnode.pre();
+      return att ? data.attSize(pre, kind) : data.size(pre, kind);
     }
 
-    int s = 1;
-    AxisIter ai = node.attributes();
-    while(ai.next() != null) ++s;
+    int size = 1;
+    BasicNodeIter iter = node.attributes();
+    while(iter.next() != null) ++size;
     if(!att) {
-      ai = node.children();
-      for(ANode i; (i = ai.next()) != null;) s += size(i, false);
+      for(final ANode child : node.children()) size += size(child, false);
     }
-    return s;
+    return size;
   }
 
   /**
@@ -281,34 +265,34 @@
   public static ANode stripNS(final ANode node, final byte[] ns, final Context ctx) {
     if(node.type != NodeType.ELM) return node;
 
-    final MemData md = new MemData(ctx.options);
-    final DataBuilder db = new DataBuilder(md);
+    final MemData data = new MemData(ctx.options);
+    final DataBuilder db = new DataBuilder(data);
     db.build(node);
 
     // flag indicating if namespace should be completely removed
     boolean del = true;
     // loop through all nodes
-    for(int pre = 0; pre < md.meta.size; pre++) {
+    for(int pre = 0; pre < data.meta.size; pre++) {
       // only check elements and attributes
-      final int kind = md.kind(pre);
+      final int kind = data.kind(pre);
       if(kind != Data.ELEM && kind != Data.ATTR) continue;
       // check if namespace is referenced
-      final byte[] uri = md.nspaces.uri(md.uri(pre, kind));
+      final byte[] uri = data.nspaces.uri(data.uriId(pre, kind));
       if(uri == null || !eq(uri, ns)) continue;
 
-      final byte[] nm = md.name(pre, kind);
+      final byte[] nm = data.name(pre, kind);
       if(prefix(nm).length == 0) {
         // no prefix: remove namespace from element
         if(kind == Data.ELEM) {
-          md.update(pre, Data.ELEM, nm, EMPTY);
-          md.nsFlag(pre, false);
+          data.update(pre, Data.ELEM, nm, EMPTY);
+          data.nsFlag(pre, false);
         }
       } else {
         // prefix: retain namespace
         del = false;
       }
     }
-    if(del) md.nspaces.delete(ns);
-    return new DBNode(md);
+    if(del) data.nspaces.delete(ns);
+    return new DBNode(data);
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/DataFTBuilder.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/DataFTBuilder.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/DataFTBuilder.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/DataFTBuilder.java	2015-07-14 10:54:40.000000000 +0000
@@ -5,13 +5,13 @@
 import java.util.*;
 
 import org.basex.core.*;
-import org.basex.data.*;
+import org.basex.query.util.ft.*;
 import org.basex.query.value.node.*;
 import org.basex.util.*;
 import org.basex.util.ft.*;
 
 /**
- * Class for constructing decorated full-text nodes.
+ * Constructor for marked full-text results.
  *
  * @author BaseX Team 2005-15, BSD License
  * @author Christian Gruen
@@ -23,15 +23,28 @@
   private final FTPosData pos;
   /** Length of full-text extract. */
   private final int len;
+  /** Id of marker element name. */
+  private final int name;
 
   /**
    * Constructor.
    * @param pos full-text position data
    * @param len length of extract
+   * @param name id of marker element name
    */
-  DataFTBuilder(final FTPosData pos, final int len) {
+  DataFTBuilder(final FTPosData pos, final int len, final int name) {
     this.pos = pos;
     this.len = len;
+    this.name = name;
+  }
+
+
+  /**
+   * Returns the id of the marker element name.
+   * @return id
+   */
+  int name() {
+    return name;
   }
 
   /**
@@ -45,7 +58,7 @@
 
     // not all nodes have full-text positions
     final DBNode dbnode = (DBNode) node;
-    final FTPos ftp = pos.get(dbnode.data, dbnode.pre);
+    final FTPos ftp = pos.get(dbnode.data(), dbnode.pre());
     if(ftp == null) return null;
 
     final ArrayList<DataFTMarker> marks = new ArrayList<>();
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/fingertree/Deep.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/fingertree/Deep.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/fingertree/Deep.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/fingertree/Deep.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,869 +0,0 @@
-package org.basex.query.util.fingertree;
-
-import java.util.*;
-
-/**
- * A <i>deep</i> node containing elements in the left and right digit and a sub-tree in
- * the middle.
- *
- * @author BaseX Team 2005-15, BSD License
- * @author Leo Woerteler
- *
- * @param <N> node type
- * @param <E> element type
- */
-final class Deep<N, E> extends FingerTree<N, E> {
-  /** Left digit. */
-  final Node<N, E>[] left;
-  /** Size of the left digit, cached for speeding up indexing. */
-  final long leftSize;
-  /** Middle tree. */
-  final FingerTree<Node<N, E>, E> middle;
-  /** Right digit. */
-  final Node<N, E>[] right;
-
-  /** Size of this tree. */
-  final long size;
-
-  /**
-   * Constructor.
-   * @param left left digit
-   * @param leftSize size of the left digit
-   * @param middle middle tree
-   * @param right right digit
-   * @param size size of this tree
-   */
-  Deep(final Node<N, E>[] left, final long leftSize,
-      final FingerTree<Node<N, E>, E> middle, final Node<N, E>[] right, final long size) {
-    this.left = left;
-    this.leftSize = leftSize;
-    this.middle = middle;
-    this.right = right;
-    this.size = size;
-  }
-
-  /**
-   * Factory method calculating the size of the left digit.
-   * @param <N> node type
-   * @param <E> element type
-   * @param left left digit
-   * @param middle middle tree
-   * @param right right digit
-   * @param size size of this tree
-   * @return the deep node
-   */
-  static <N, E> Deep<N, E> get(final Node<N, E>[] left, final FingerTree<Node<N, E>, E> middle,
-      final Node<N, E>[] right, final long size) {
-    return new Deep<>(left, size(left), middle, right, size);
-  }
-
-  /**
-   * Factory method for deep nodes with an empty middle tree.
-   * @param <N> node type
-   * @param <E> element type
-   * @param left left digit
-   * @param leftSize size of the left sub-tree
-   * @param right right digit
-   * @param size size of this tree
-   * @return the deep node
-   */
-  static <N, E> Deep<N, E> get(final Node<N, E>[] left, final long leftSize,
-      final Node<N, E>[] right, final long size) {
-    return new Deep<>(left, leftSize, Empty.<Node<N, E>, E>getInstance(), right, size);
-  }
-
-  /**
-   * Factory method for deep nodes with an empty middle tree calculating the size of the left digit.
-   * @param <N> node type
-   * @param <E> element type
-   * @param left left digit
-   * @param right right digit
-   * @param size size of this tree
-   * @return the deep node
-   */
-  static <N, E> Deep<N, E> get(final Node<N, E>[] left, final Node<N, E>[] right, final long size) {
-    return new Deep<>(left, size(left), Empty.<Node<N, E>, E>getInstance(), right, size);
-  }
-
-  /**
-   * Factory method for deep nodes calculating all cached sizes.
-   * @param <N> node type
-   * @param <E> element type
-   * @param left left digit
-   * @param middle middle sub-tree
-   * @param right right digit
-   * @return the deep node
-   */
-  static <N, E> Deep<N, E> get(final Node<N, E>[] left,
-      final FingerTree<Node<N, E>, E> middle, final Node<N, E>[] right) {
-    final long l = size(left), m = middle.size(), r = size(right);
-    return new Deep<>(left, l, middle, right, l + m + r);
-  }
-
-  /**
-   * Factory method for deep nodes with empty middle tree calculating all cached sizes.
-   * @param <N> node type
-   * @param <E> element type
-   * @param left left digit
-   * @param right right digit
-   * @return the deep node
-   */
-  static <N, E> Deep<N, E> get(final Node<N, E>[] left, final Node<N, E>[] right) {
-    final long l = size(left), r = size(right);
-    return new Deep<>(left, l, Empty.<Node<N, E>, E>getInstance(), right, l + r);
-  }
-
-  @Override
-  public Deep<N, E> cons(final Node<N, E> fst) {
-    if(left.length < 4) {
-      final Node<N, E>[] newLeft = slice(left, -1, left.length);
-      newLeft[0] = fst;
-      return new Deep<>(newLeft, leftSize + fst.size(), middle, right, size + fst.size());
-    }
-
-    final Node<N, E>[] newLeft = slice(left, -1, 1);
-    newLeft[0] = fst;
-    final FingerTree<Node<N, E>, E> mid = middle.cons(new InnerNode3<>(left[1], left[2], left[3]));
-    return Deep.get(newLeft, mid, right, size + fst.size());
-  }
-
-  @Override
-  public Deep<N, E> snoc(final Node<N, E> lst) {
-    if(right.length < 4) {
-      final Node<N, E>[] newRight = slice(right, 0, right.length + 1);
-      newRight[right.length] = lst;
-      return new Deep<>(left, leftSize, middle, newRight, size + lst.size());
-    }
-
-    final FingerTree<Node<N, E>, E> mid =
-        middle.snoc(new InnerNode3<>(right[0], right[1], right[2]));
-    final Node<N, E>[] newRight = slice(right, 3, 5);
-    newRight[1] = lst;
-    return new Deep<>(left, leftSize, mid, newRight, size + lst.size());
-  }
-
-  @Override
-  public Node<N, E> head() {
-    return left[0];
-  }
-
-  @Override
-  public Node<N, E> last() {
-    return right[right.length - 1];
-  }
-
-  @Override
-  public FingerTree<N, E> init() {
-    final long newSize = size - right[right.length - 1].size();
-
-    if(right.length > 1) {
-      // right digit is safe, just shrink it
-      return new Deep<>(left, leftSize, middle, slice(right, 0, right.length - 1), newSize);
-    }
-
-    if(middle.isEmpty()) {
-      // middle tree empty, make a tree from the left list
-      if(left.length == 1) return new Single<>(left[0]);
-
-      final int mid = left.length / 2;
-      final Node<N, E>[] newLeft = slice(left, 0, mid);
-      return Deep.get(newLeft, slice(left, mid, left.length), newSize);
-    }
-
-    // extract values for the right digit from the middle
-    final InnerNode<N, E> last = (InnerNode<N, E>) middle.last();
-    return new Deep<>(left, leftSize, middle.init(), last.copyChildren(), newSize);
-  }
-
-  @Override
-  public FingerTree<N, E> tail() {
-    final long fstSize = left[0].size();
-    final long newSize = size - fstSize;
-
-    if(left.length > 1) {
-      // left digit is safe, just shrink it
-      return new Deep<>(slice(left, 1, left.length), leftSize - fstSize, middle, right, newSize);
-    }
-
-    if(middle.isEmpty()) {
-      // middle tree empty, make a tree from the right list
-      if(right.length == 1) return new Single<>(right[0]);
-
-      final int mid = right.length / 2;
-      return Deep.get(slice(right, 0, mid), slice(right, mid, right.length), newSize);
-    }
-
-    // extract values for the left digit from the middle
-    final InnerNode<N, E> head = (InnerNode<N, E>) middle.head();
-    return new Deep<>(head.copyChildren(), head.size(), middle.tail(), right, newSize);
-  }
-
-  @Override
-  public long size() {
-    return this.size;
-  }
-
-  @Override
-  public Deep<N, E> concat(final Node<N, E>[] nodes, final FingerTree<N, E> other) {
-    final Deep<N, E> lft = (Deep<N, E>) addAll(nodes, false);
-    if(!(other instanceof Deep)) {
-      return other instanceof Single ? lft.snoc(((Single<N, E>) other).elem) : lft;
-    }
-
-    final Deep<N, E> rght = (Deep<N, E>) other;
-    final Node<N, E>[] as = lft.right, bs = rght.left;
-    final int l = as.length, n = l + bs.length, k = (n + 2) / 3;
-    @SuppressWarnings("unchecked")
-    final Node<Node<N, E>, E>[] out = new Node[k];
-    int p = 0;
-    for(int i = 0; i < k; i++) {
-      final int rest = n - p;
-      final Node<N, E> x = p < l ? as[p] : bs[p - l];
-      p++;
-      final Node<N, E> y = p < l ? as[p] : bs[p - l];
-      p++;
-      if(rest > 4 || rest == 3) {
-        final Node<N, E> z = p < l ? as[p] : bs[p - l];
-        out[i] = new InnerNode3<>(x, y, z);
-        p++;
-      } else {
-        out[i] = new InnerNode2<>(x, y);
-      }
-    }
-
-    final FingerTree<Node<N, E>, E> newMid = lft.middle.concat(out, rght.middle);
-    final long newSize = lft.leftSize + newMid.size() + rght.rightSize();
-    return new Deep<>(lft.left, lft.leftSize, newMid, rght.right, newSize);
-  }
-
-  @Override
-  public FingerTree<N, E> reverse() {
-    final int l = left.length, r = right.length;
-    @SuppressWarnings("unchecked")
-    final Node<N, E>[] newLeft = new Node[r], newRight = new Node[l];
-    for(int i = 0; i < r; i++) newLeft[i] = right[r - 1 - i].reverse();
-    for(int i = 0; i < l; i++) newRight[i] = left[l - 1 - i].reverse();
-    return new Deep<>(newLeft, rightSize(), middle.reverse(), newRight, size);
-  }
-
-  @Override
-  public FingerTree<N, E> insert(final long pos, final E val) {
-    if(pos <= leftSize) {
-      // insert into left digit
-      int i = 0;
-      long p = pos;
-      for(;; i++) {
-        final long sub = left[i].size();
-        if(p <= sub) break;
-        p -= sub;
-      }
-
-      final int ll = left.length;
-      final Node<N, E> l = i > 0 ? left[i - 1] : null, r = i + 1 < ll ? left[i + 1] : null;
-      @SuppressWarnings("unchecked")
-      final Node<N, E>[] siblings = new Node[] { l, null, r, null };
-      if(!left[i].insert(siblings, p, val)) {
-        // no split
-        final Node<N, E>[] newLeft = left.clone();
-        if(i > 0) newLeft[i - 1] = siblings[0];
-        newLeft[i] = siblings[1];
-        if(i + 1 < ll) newLeft[i + 1] = siblings[2];
-        return new Deep<>(newLeft, leftSize + 1, middle, right, size + 1);
-      }
-
-      // node was split
-      @SuppressWarnings("unchecked")
-      final Node<N, E>[] temp = new Node[ll + 1];
-      if(i > 0) {
-        System.arraycopy(left, 0, temp, 0, i - 1);
-        temp[i - 1] = siblings[0];
-      }
-      temp[i] = siblings[1];
-      temp[i + 1] = siblings[2];
-      if(i + 1 < ll) {
-        temp[i + 2] = siblings[3];
-        System.arraycopy(left, i + 2, temp, i + 3, ll - i - 2);
-      }
-      if(ll < 4) return new Deep<>(temp, leftSize + 1, middle, right, size + 1);
-
-      // digit has to be split
-      final Node<N, E> a = temp[0], b = temp[1];
-      @SuppressWarnings("unchecked")
-      final Node<N, E>[] newLeft = new Node[] { a, b };
-      final Node<Node<N, E>, E> sub = new InnerNode3<>(temp[2], temp[3], temp[4]);
-      return new Deep<>(newLeft, a.size() + b.size(), middle.cons(sub), right, size + 1);
-    }
-
-    long p = pos - leftSize;
-    final long midSize = middle.size();
-    if(p < midSize) return new Deep<>(left, leftSize, middle.insert(p, val), right, size + 1);
-
-    // insert into right digit
-    p -= midSize;
-    int i = 0;
-    for(;; i++) {
-      final long sub = right[i].size();
-      if(p <= sub) break;
-      p -= sub;
-    }
-
-    final int rl = right.length;
-    final Node<N, E> l = i > 0 ? right[i - 1] : null, r = i + 1 < rl ? right[i + 1] : null;
-    @SuppressWarnings("unchecked")
-    final Node<N, E>[] siblings = new Node[] { l, null, r, null };
-    if(!right[i].insert(siblings, p, val)) {
-      // no split
-      final Node<N, E>[] newRight = right.clone();
-      if(i > 0) newRight[i - 1] = siblings[0];
-      newRight[i] = siblings[1];
-      if(i + 1 < rl) newRight[i + 1] = siblings[2];
-      return new Deep<>(left, leftSize, middle, newRight, size + 1);
-    }
-
-    // node was split
-    @SuppressWarnings("unchecked")
-    final Node<N, E>[] temp = new Node[rl + 1];
-    if(i > 0) {
-      System.arraycopy(right, 0, temp, 0, i - 1);
-      temp[i - 1] = siblings[0];
-    }
-    temp[i] = siblings[1];
-    temp[i + 1] = siblings[2];
-    if(i + 1 < rl) {
-      temp[i + 2] = siblings[3];
-      System.arraycopy(right, i + 2, temp, i + 3, rl - i - 2);
-    }
-    if(right.length < 4) return new Deep<>(left, leftSize, middle, temp, size + 1);
-
-    // digit has to be split
-    final Node<Node<N, E>, E> sub = new InnerNode3<>(temp[0], temp[1], temp[2]);
-    final Node<N, E> a = temp[3], b = temp[4];
-    @SuppressWarnings("unchecked")
-    final Node<N, E>[] newRight = new Node[] { a, b};
-    return new Deep<>(left, leftSize, middle.snoc(sub), newRight, size + 1);
-  }
-
-  @Override
-  public TreeSlice<N, E> remove(final long pos) {
-    if(pos < leftSize) return new TreeSlice<>(removeLeft(pos));
-    final long rightStart = leftSize + middle.size();
-    if(pos >= rightStart) return new TreeSlice<>(removeRight(pos - rightStart));
-
-    final TreeSlice<Node<N, E>, E> slice = middle.remove(pos - leftSize);
-    if(slice.isTree()) {
-      // no underflow
-      final FingerTree<Node<N, E>, E> newMiddle = slice.getTree();
-      return slice.setTree(new Deep<>(left, leftSize, newMiddle, right, size - 1));
-    }
-
-    // middle tree had an underflow, one sub-node left
-    final Node<N, E> node = (Node<N, E>) ((PartialInnerNode<N, E>) slice.getPartial()).sub;
-
-    // try to extend the smaller digit
-    if(left.length < right.length) {
-      // merge into left digit
-      final Node<N, E>[] newLeft = slice(left, 0, left.length + 1);
-      newLeft[left.length] = node;
-      return slice.setTree(Deep.get(newLeft, leftSize + node.size(), right, size - 1));
-    }
-
-    if(right.length < 4) {
-      // merge into right digit
-      @SuppressWarnings("unchecked")
-      final Node<N, E>[] newRight = new Node[right.length + 1];
-      newRight[0] = node;
-      System.arraycopy(right, 0, newRight, 1, right.length);
-      return slice.setTree(Deep.get(left, leftSize, newRight, size - 1));
-    }
-
-    // redistribute the 9 nodes
-    final Node<N, E>[] newLeft = slice(left, 0, 3);
-    final Node<Node<N, E>, E> newMid = new InnerNode3<>(left[3], node, right[0]);
-    final Node<N, E>[] newRight = slice(right, 1, right.length);
-    return slice.setTree(Deep.get(newLeft, new Single<>(newMid), newRight, size - 1));
-  }
-
-  /**
-   * Remove an element from the left digit.
-   * @param pos position inside the left digit
-   * @return resulting tree
-   */
-  private FingerTree<N, E> removeLeft(final long pos) {
-    if(left.length > 1) {
-      // left digit cannot underflow, just delete the element
-      return new Deep<>(remove(left, pos), leftSize - 1, middle, right, size - 1);
-    }
-
-    // singleton digit might underflow
-    final Node<N, E> node = left[0];
-
-    if(!middle.isEmpty()) {
-      // next node for balancing is in middle tree
-      final InnerNode<N, E> head = (InnerNode<N, E>) middle.head();
-      final Node<N, E> first = head.getSub(0);
-      final Node<N, E>[] rem = node.remove(null, first, pos);
-      final Node<N, E> newNode = rem[1], newFirst = rem[2];
-
-      if(newNode == null) {
-        // nodes were merged
-        final Node<N, E>[] newLeft = head.copyChildren();
-        newLeft[0] = newFirst;
-        return Deep.get(newLeft, middle.tail(), right, size - 1);
-      }
-
-      @SuppressWarnings("unchecked")
-      final Node<N, E>[] newLeft = new Node[] { newNode };
-
-      if(newFirst != first) {
-        // nodes were balanced
-        final FingerTree<Node<N, E>, E> newMid = middle.replaceHead(head.replaceFirst(newFirst));
-        return new Deep<>(newLeft, newNode.size(), newMid, right, size - 1);
-      }
-
-      // no changes to this tree's structure
-      return new Deep<>(newLeft, newNode.size(), middle, right, size - 1);
-    }
-
-    // potentially balance with right digit
-    final Node<N, E>[] rem = node.remove(null, right[0], pos);
-    final Node<N, E> newNode = rem[1], newFirstRight = rem[2];
-
-    if(newNode == null) {
-      // nodes were merged
-      if(right.length == 1) return new Single<>(newFirstRight);
-      final int mid = right.length / 2;
-      final Node<N, E>[] newLeft = slice(right, 0, mid);
-      newLeft[0] = newFirstRight;
-      return Deep.get(newLeft, middle, slice(right, mid, right.length), size - 1);
-    }
-
-    // structure does not change
-    @SuppressWarnings("unchecked")
-    final Node<N, E>[] newLeft = new Node[] { newNode };
-
-    if(newFirstRight == right[0]) {
-      // right digit stays the same
-      return new Deep<>(newLeft, newLeft[0].size(), middle, right, size - 1);
-    }
-
-    // adapt the right digit
-    final Node<N, E>[] newRight = right.clone();
-    newRight[0] = newFirstRight;
-    return new Deep<>(newLeft, newNode.size(), middle, newRight, size - 1);
-  }
-
-  /**
-   * Remove an element from the right digit.
-   * @param pos position inside the right digit
-   * @return resulting tree
-   */
-  private FingerTree<N, E> removeRight(final long pos) {
-    if(right.length > 1) {
-      // right digit cannot underflow, just delete the element
-      return new Deep<>(left, leftSize, middle, remove(right, pos), size - 1);
-    }
-
-    // singleton digit might underflow
-    final Node<N, E> node = right[0];
-
-    if(!middle.isEmpty()) {
-      // potentially balance with middle tree
-      final InnerNode<N, E> last = (InnerNode<N, E>) middle.last();
-      final Node<N, E> lastSub = last.getSub(last.arity() - 1);
-      final Node<N, E>[] rem = node.remove(lastSub, null, pos);
-      final Node<N, E> newLastSub = rem[0], newNode = rem[1];
-
-      if(newNode == null) {
-        // nodes were merged
-        final Node<N, E>[] newRight = last.copyChildren();
-        newRight[newRight.length - 1] = newLastSub;
-        return new Deep<>(left, leftSize, middle.init(), newRight, size - 1);
-      }
-
-      @SuppressWarnings("unchecked")
-      final Node<N, E>[] newRight = new Node[] { newNode };
-
-      // replace last node in middle tree
-      final Node<Node<N, E>, E> newLast = last.replaceLast(newLastSub);
-      return new Deep<>(left, leftSize, middle.replaceLast(newLast), newRight, size - 1);
-    }
-
-    // balance with left digit
-    final Node<N, E> lastLeft = left[left.length - 1];
-    final Node<N, E>[] rem = node.remove(lastLeft, null, pos);
-    final Node<N, E> newLastLeft = rem[0], newNode = rem[1];
-    if(newNode == null) {
-      // nodes were merged
-      if(left.length == 1) {
-        // only one node left
-        return new Single<>(newLastLeft);
-      }
-
-      @SuppressWarnings("unchecked")
-      final Node<N, E>[] newRight = new Node[] { newLastLeft };
-      return Deep.get(slice(left, 0, left.length - 1), newRight, size - 1);
-    }
-
-    @SuppressWarnings("unchecked")
-    final Node<N, E>[] newRight = new Node[] { newNode };
-
-    if(newLastLeft == lastLeft) {
-      // deletion could be absorbed
-      return Deep.get(left, leftSize, newRight, size - 1);
-    }
-
-    // adapt the left digit
-    final Node<N, E>[] newLeft = left.clone();
-    newLeft[newLeft.length - 1] = newLastLeft;
-    return Deep.get(newLeft, newRight, size - 1);
-  }
-
-  /**
-   * Deletes an element from the given digit containing at least two nodes.
-   * @param <N> node type
-   * @param <E> element type
-   * @param arr array of nodes
-   * @param pos deletion position
-   * @return new digit
-   */
-  private static <N, E> Node<N, E>[] remove(final Node<N, E>[] arr, final long pos) {
-    int i = 0;
-    long off = pos;
-    Node<N, E> node;
-    for(;;) {
-      node = arr[i];
-      final long nodeSize = node.size();
-      if(off < nodeSize) break;
-      off -= nodeSize;
-      i++;
-    }
-
-    final int n = arr.length;
-    final Node<N, E>[] res = arr[i].remove(i == 0     ? null : arr[i - 1],
-                                           i == n - 1 ? null : arr[i + 1], off);
-    if(res[1] != null) {
-      // same number of nodes
-      final Node<N, E>[] out = arr.clone();
-      if(i > 0) out[i - 1] = res[0];
-      out[i] = res[1];
-      if(i < n - 1) out[i + 1] = res[2];
-      return out;
-    }
-
-    // the node was merged
-    @SuppressWarnings("unchecked")
-    final Node<N, E>[] out = new Node[n - 1];
-    if(i > 0) {
-      // nodes to the left
-      System.arraycopy(arr, 0, out, 0, i - 1);
-      out[i - 1] = res[0];
-    }
-
-    if(i < n - 1) {
-      // nodes to the right
-      out[i] = res[2];
-      System.arraycopy(arr, i + 2, out, i + 1, n - i - 2);
-    }
-
-    return out;
-  }
-
-  @Override
-  public TreeSlice<N, E> slice(final long from, final long len) {
-    if(from == 0 && len == size) return new TreeSlice<>(this);
-    final long midSize = middle.size(), rightOff = leftSize + midSize;
-
-    final long inLeft = from + len <= leftSize ? len : from < leftSize ? leftSize - from : 0;
-    final long inRight = from >= rightOff ? len : from + len > rightOff ? from + len - rightOff : 0;
-
-    @SuppressWarnings("unchecked")
-    final NodeLike<N, E>[] buffer = new NodeLike[9];
-    int inBuffer = splitDigit(left, from, inLeft, buffer, 0);
-    if(inLeft == len) {
-      final int n = inBuffer;
-      if(n == 1) {
-        if(buffer[0] instanceof PartialNode) return new TreeSlice<>((PartialNode<N, E>) buffer[0]);
-        final Node<N, E> node = (Node<N, E>) buffer[0];
-        return new TreeSlice<>(new Single<>(node));
-      }
-
-      final int mid1 = n / 2;
-      final Node<N, E>[] ls = Deep.slice(buffer, 0, mid1), rs = Deep.slice(buffer, mid1, n);
-      return new TreeSlice<>(Deep.get(ls, rs, len));
-    }
-
-    final long inMiddle = len - inLeft - inRight;
-    final FingerTree<Node<N, E>, E> mid;
-    final TreeSlice<Node<N, E>, E> slice;
-    if(inMiddle == 0) {
-      mid = Empty.getInstance();
-      slice = new TreeSlice<>(mid);
-    } else {
-      final long midOff = from <= leftSize ? 0 : from - leftSize;
-      slice = middle.slice(midOff, inMiddle);
-      if(!slice.isTree()) {
-        final NodeLike<N, E> sub = ((PartialInnerNode<N, E>) slice.getPartial()).sub;
-        inBuffer = sub.append(buffer, inBuffer);
-        mid = Empty.getInstance();
-      } else {
-        mid = slice.getTree();
-      }
-    }
-
-    final long rightFrom = from < rightOff ? 0 : from - rightOff;
-    if(mid.isEmpty()) {
-      inBuffer = splitDigit(right, rightFrom, inRight, buffer, inBuffer);
-      return slice.setNodes(buffer, inBuffer, len);
-    }
-
-    final FingerTree<Node<N, E>, E> mid2;
-    if(inBuffer > 1 || buffer[0] instanceof Node) {
-      mid2 = mid;
-    } else {
-      final InnerNode<N, E> head = (InnerNode<N, E>) mid.head();
-      final int k = head.arity();
-      inBuffer = head.getSub(0).append(buffer, inBuffer);
-      for(int i = 1; i < k; i++) buffer[inBuffer++] = head.getSub(i);
-      mid2 = mid.tail();
-    }
-
-    if(mid2.isEmpty()) {
-      inBuffer = splitDigit(right, rightFrom, inRight, buffer, inBuffer);
-      return slice.setNodes(buffer, inBuffer, len);
-    }
-
-    final Node<N, E>[] newLeft = slice(buffer, 0, inBuffer);
-    inBuffer = splitDigit(right, rightFrom, inRight, buffer, 0);
-
-    final FingerTree<Node<N, E>, E> mid3;
-    final Node<N, E>[] newRight;
-    if(inBuffer == 0) {
-      mid3 = mid2.init();
-      newRight = ((InnerNode<N, E>) mid2.last()).copyChildren();
-    } else if(inBuffer > 1 || buffer[0] instanceof Node) {
-      mid3 = mid2;
-      newRight = slice(buffer, 0, inBuffer);
-    } else {
-      final NodeLike<N, E> partial = buffer[0];
-      final InnerNode<N, E> last = (InnerNode<N, E>) mid2.last();
-      final int k = last.arity();
-      for(int i = 0; i < k; i++) buffer[i] = last.getSub(i);
-      inBuffer = partial.append(buffer, k);
-      mid3 = mid2.init();
-      newRight = slice(buffer, 0, inBuffer);
-    }
-
-    return slice.setTree(Deep.get(newLeft, mid3, newRight, len));
-  }
-
-  /**
-   * Creates a tree slice from a digit.
-   * @param <N> node type
-   * @param <E> element type
-   * @param nodes the digit
-   * @param from element offset
-   * @param len number of elements
-   * @param buffer buffer to insert the node slice into
-   * @param inBuffer initial number of nodes in the buffer
-   * @return the slice
-   */
-  private static <N, E> int splitDigit(final Node<N, E>[] nodes, final long from,
-      final long len, final NodeLike<N, E>[] buffer, final int inBuffer) {
-    if(len <= 0) return inBuffer;
-
-    // find the first sub-node containing used elements
-    int firstPos = 0;
-    long firstOff = from;
-    Node<N, E> first = nodes[0];
-    long firstSize = first.size();
-    while(firstOff >= firstSize) {
-      firstOff -= firstSize;
-      first = nodes[++firstPos];
-      firstSize = first.size();
-    }
-
-    // firstOff < firstSize
-    final long inFirst = firstSize - firstOff;
-    if(inFirst >= len) {
-      // everything in first sub-node
-      final NodeLike<N, E> part = len == firstSize ? first : first.slice(firstOff, len);
-      return part.append(buffer, inBuffer);
-    }
-
-    final NodeLike<N, E> firstSlice = firstOff == 0 ? first : first.slice(firstOff, inFirst);
-    int numMerged = firstSlice.append(buffer, inBuffer);
-
-    int pos = firstPos;
-    long remaining = len - inFirst;
-    while(remaining > 0) {
-      final Node<N, E> curr = nodes[++pos];
-      final long currSize = curr.size();
-      final NodeLike<N, E> slice = remaining >= currSize ? curr : curr.slice(0, remaining);
-      numMerged = slice.append(buffer, numMerged);
-      remaining -= currSize;
-    }
-
-    return numMerged;
-  }
-
-  @Override
-  public ListIterator<E> listIterator(final boolean reverse) {
-    return new DeepTreeIterator<>(this, reverse);
-  }
-
-  /**
-   * Calculates the size of the right digit.
-   * @return number of elements in the right digit
-   */
-  private long rightSize() {
-    return size - leftSize - middle.size();
-  }
-
-  @Override
-  FingerTree<N, E> addAll(final Node<N, E>[] nodes, final boolean appendLeft) {
-    final int k = nodes.length;
-    if(k == 0) return this;
-    if(k == 1) return appendLeft ? cons(nodes[0]) : snoc(nodes[0]);
-
-    if(appendLeft) {
-      int l = k + left.length;
-      final Node<N, E>[] ls = slice(nodes, 0, l);
-      System.arraycopy(left, 0, ls, k, left.length);
-      if(l <= 4) return Deep.get(ls, middle, right);
-      FingerTree<Node<N, E>, E> newMid = middle;
-      for(; l > 4; l -= 3) {
-        final InnerNode<N, E> sub = new InnerNode3<>(ls[l - 3], ls[l - 2], ls[l - 1]);
-        newMid = newMid.cons(sub);
-      }
-      return Deep.get(slice(ls, 0, l), newMid, right);
-    }
-
-    final int r = right.length + k;
-    final Node<N, E>[] rs = slice(right, 0, r);
-    System.arraycopy(nodes, 0, rs, right.length, k);
-    if(k + right.length <= 4) return Deep.get(left, middle, rs);
-    FingerTree<Node<N, E>, E> newMid = middle;
-    int i = 0;
-    for(; r - i > 4; i += 3) {
-      final InnerNode<N, E> sub = new InnerNode3<>(rs[i], rs[i + 1], rs[i + 2]);
-      newMid = newMid.snoc(sub);
-    }
-    return Deep.get(left, newMid, slice(rs, i, r));
-  }
-
-  @Override
-  public FingerTree<N, E> replaceHead(final Node<N, E> head) {
-    final long sizeDiff = head.size() - left[0].size();
-    final Node<N, E>[] newLeft = left.clone();
-    newLeft[0] = head;
-    return new Deep<>(newLeft, leftSize + sizeDiff, middle, right, size + sizeDiff);
-  }
-
-  @Override
-  public FingerTree<N, E> replaceLast(final Node<N, E> last) {
-    final int lst = right.length - 1;
-    final Node<N, E>[] newRight = right.clone();
-    newRight[lst] = last;
-    return new Deep<>(left, leftSize, middle, newRight, size + last.size()
-        - right[lst].size());
-  }
-
-  @Override
-  void toString(final StringBuilder sb, final int indent) {
-    for(int i = 0; i < indent; i++)
-      sb.append("  ");
-    sb.append("Deep[\n");
-
-    // left digit
-    for(int i = 0; i < indent + 1; i++)
-      sb.append("  ");
-    sb.append("Left[\n");
-    for(final Node<N, E> e : left) {
-      e.toString(sb, indent + 2);
-      sb.append('\n');
-    }
-    for(int i = 0; i < indent + 1; i++)
-      sb.append("  ");
-    sb.append("]\n");
-
-    // middle tree
-    middle.toString(sb, indent + 1);
-    sb.append('\n');
-
-    // right digit
-    for(int i = 0; i < indent + 1; i++)
-      sb.append("  ");
-    sb.append("Right[\n");
-    for(final Node<N, E> e : right) {
-      e.toString(sb, indent + 2);
-      sb.append("\n");
-    }
-    for(int i = 0; i < indent + 1; i++)
-      sb.append("  ");
-    sb.append("]\n");
-
-    for(int i = 0; i < indent; i++)
-      sb.append("  ");
-    sb.append("]");
-  }
-
-  @Override
-  public long checkInvariants() {
-    if(left.length < 1 || left.length > 4) throw new AssertionError(
-        "Wrong left digit length: " + left.length);
-    long sz = 0;
-    for(final Node<N, E> nd : left)
-      sz += nd.checkInvariants();
-    if(sz != leftSize) throw new AssertionError("Wrong leftSize: " + leftSize + " vs. "
-        + sz);
-    sz += middle.checkInvariants();
-    if(right.length < 1 || right.length > 4) throw new AssertionError(
-        "Wrong right digit length: " + right.length);
-    for(final Node<N, E> nd : right)
-      sz += nd.checkInvariants();
-    if(sz != size) throw new AssertionError("Wrong size: " + size + " vs. " + sz);
-    return sz;
-  }
-
-  /**
-   * Calculates the size of a digit.
-   * @param <N> node type
-   * @param arr digit
-   * @return size
-   */
-  static <N extends Node<?, ?>> long size(final N[] arr) {
-    long size = 0;
-    for(final N o : arr)
-      size += o.size();
-    return size;
-  }
-
-  /**
-   * Returns an array containing the values at the indices {@code from} to {@code to - 1}
-   * in the given array. Its length is always {@code to - from}. If {@code from} is
-   * smaller than zero, the first {@code -from} entries in the resulting array are
-   * {@code null}. If {@code to > arr.length} then the last {@code to - arr.length}
-   * entries are {@code null}.
-   * @param <N> node type
-   * @param <E> element type
-   * @param arr input array
-   * @param from first index, inclusive (may be negative)
-   * @param to last index, exclusive (may be greater than {@code arr.length})
-   * @return resulting array
-   */
-  static <N, E> Node<N, E>[] slice(final NodeLike<N, E>[] arr, final int from, final int to) {
-    @SuppressWarnings("unchecked")
-    final Node<N, E>[] out = new Node[to - from];
-    final int in0 = Math.max(0, from), in1 = Math.min(to, arr.length);
-    final int out0 = Math.max(-from, 0);
-    System.arraycopy(arr, in0, out, out0, in1 - in0);
-    return out;
-  }
-
-  @Override
-  public long[] sizes(final int depth) {
-    final long[] sizes = middle.sizes(depth + 1);
-    sizes[depth] = size - middle.size();
-    return sizes;
-  }
-}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/fingertree/DeepTreeIterator.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/fingertree/DeepTreeIterator.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/fingertree/DeepTreeIterator.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/fingertree/DeepTreeIterator.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,275 +0,0 @@
-package org.basex.query.util.fingertree;
-
-import java.util.*;
-
-/**
- * Iterator over a finger tree with at least two sub-nodes.
- *
- * @author BaseX Team 2005-15, BSD License
- * @author Leo Woerteler
- *
- * @param <E> element type
- */
-final class DeepTreeIterator<E> implements ListIterator<E> {
-  /** Current index. */
-  private long index;
-
-  /** Stack of deep trees. */
-  private Deep<?, E>[] trees;
-  /** Position of the current node in the digits. */
-  private int deepPos;
-  /** Stack pointer for the deep trees. */
-  private int tTop;
-
-  /** Node stack. */
-  private InnerNode<?, E>[] nodes;
-  /** Position stack. */
-  private int[] poss;
-  /** Stack pointer. */
-  private int nTop;
-
-  /** Current leaf node. */
-  private Node<E, E> leaf;
-  /** Position inside the current leaf. */
-  private int leafPos;
-
-  /**
-   * Constructor.
-   * @param root root node
-   * @param reverse flag for starting at the end
-   */
-  @SuppressWarnings("unchecked")
-  DeepTreeIterator(final Deep<?, E> root, final boolean reverse) {
-    index = reverse ? root.size : 0;
-
-    trees = new Deep[8];
-    trees[0] = root;
-    tTop = 0;
-
-    nodes = new InnerNode[8];
-    poss = new int[8];
-    nTop = -1;
-
-    Node<?, E> curr = reverse ? root.right[root.right.length - 1] : root.left[0];
-    while(curr instanceof InnerNode) {
-      final InnerNode<?, E> inner = (InnerNode<?, E>) curr;
-      final int idx = reverse ? inner.arity() - 1 : 0;
-      if(++nTop == nodes.length) {
-        nodes = Arrays.copyOf(nodes, 2 * nodes.length);
-        poss = Arrays.copyOf(poss, 2 * poss.length);
-      }
-      nodes[nTop] = inner;
-      poss[nTop] = idx;
-      curr = inner.getSub(idx);
-    }
-
-    deepPos = reverse ? root.right.length : -root.left.length;
-    leaf = (Node<E, E>) curr;
-    leafPos = reverse ? curr.arity() : 0;
-  }
-
-  @Override
-  public int nextIndex() {
-    return (int) index;
-  }
-
-  @Override
-  public boolean hasNext() {
-    return index < trees[0].size;
-  }
-
-  @Override
-  @SuppressWarnings("unchecked")
-  public E next() {
-    if(index >= trees[0].size) throw new NoSuchElementException();
-
-    index++;
-    if(leafPos < leaf.arity()) return leaf.getSub(leafPos++);
-
-    // leaf drained, backtrack
-    while(nTop >= 0 && poss[nTop] == nodes[nTop].arity() - 1) nTop--;
-
-    final Node<?, E> start;
-    if(nTop >= 0) {
-      // go to next sub-node
-      start = nodes[nTop].getSub(++poss[nTop]);
-    } else {
-      // node drained, move to the next one
-      final Deep<?, E> curr = trees[tTop];
-      if(deepPos < -1) {
-        // go to next node in digit
-        ++deepPos;
-        start = curr.left[curr.left.length + deepPos];
-      } else if(deepPos == -1) {
-        // left digit drained
-        final FingerTree<?, E> mid = curr.middle;
-        if(mid instanceof Empty) {
-          // skip empty middle tree
-          deepPos = 1;
-          start = curr.right[0];
-        } else if(mid instanceof Single) {
-          // iterate through the one middle node
-          deepPos = 0;
-          start = ((Single<?, E>) mid).elem;
-        } else {
-          final Deep<?, E> deep = (Deep<?, E>) mid;
-          if(++tTop == trees.length) {
-            final Deep<?, E>[] newTrees = new Deep[2 * tTop];
-            System.arraycopy(trees, 0, newTrees, 0, tTop);
-            trees = newTrees;
-          }
-          trees[tTop] = deep;
-          deepPos = -deep.left.length;
-          start = deep.left[0];
-        }
-      } else if(deepPos == 0) {
-        // we are in a single middle node
-        deepPos = 1;
-        start = curr.right[0];
-      } else {
-        // we are in the right digit
-        final int p = deepPos - 1;
-        if(p < curr.right.length - 1) {
-          // go to next node in digit
-          deepPos++;
-          start = curr.right[p + 1];
-        } else {
-          // backtrack one level
-          trees[tTop] = null;
-          deepPos = 0;
-          tTop--;
-          start = trees[tTop].right[0];
-          deepPos = 1;
-        }
-      }
-    }
-
-    Node<?, E> sub = start;
-    while(sub instanceof InnerNode) {
-      if(++nTop == nodes.length) {
-        final InnerNode<?, E>[] newNodes = new InnerNode[2 * nTop];
-        System.arraycopy(nodes, 0, newNodes, 0, nTop);
-        nodes = newNodes;
-        poss = Arrays.copyOf(poss, 2 * nTop);
-      }
-      nodes[nTop] = (InnerNode<?, E>) sub;
-      poss[nTop] = 0;
-      sub = nodes[nTop].getSub(0);
-    }
-
-    leaf = (Node<E, E>) sub;
-    leafPos = 1;
-    return leaf.getSub(0);
-  }
-
-  @Override
-  public int previousIndex() {
-    return (int) (index - 1);
-  }
-
-  @Override
-  public boolean hasPrevious() {
-    return index > 0;
-  }
-
-  @Override
-  @SuppressWarnings("unchecked")
-  public E previous() {
-    if(index <= 0) throw new NoSuchElementException();
-
-    --index;
-    if(leafPos > 0) return leaf.getSub(--leafPos);
-
-    // leaf drained, backtrack
-    while(nTop >= 0 && poss[nTop] == 0) nTop--;
-
-    final Node<?, E> start;
-    if(nTop >= 0) {
-      // go to previous sub-node
-      start = nodes[nTop].getSub(--poss[nTop]);
-    } else {
-      // node drained, move to the previous one
-      final Deep<?, E> curr = trees[tTop];
-      if(deepPos > 1) {
-        // go to next node in right digit
-        --deepPos;
-        start = curr.right[deepPos - 1];
-      } else if(deepPos == 1) {
-        // right digit drained
-        final FingerTree<?, E> mid = curr.middle;
-        if(mid instanceof Empty) {
-          // skip empty middle tree
-          final int l = curr.left.length;
-          start = curr.left[l - 1];
-          deepPos = -1;
-        } else if(mid instanceof Single) {
-          // iterate through the one middle node
-          start = ((Single<?, E>) mid).elem;
-          deepPos = 0;
-        } else {
-          // go into the middle tree
-          final Deep<?, E> deep = (Deep<?, E>) mid;
-          if(++tTop == trees.length) {
-            final Deep<?, E>[] newTrees = new Deep[2 * tTop];
-            System.arraycopy(trees, 0, newTrees, 0, tTop);
-            trees = newTrees;
-          }
-          trees[tTop] = deep;
-          final int r = deep.right.length;
-          start = deep.right[r - 1];
-          deepPos = r;
-        }
-      } else if(deepPos == 0) {
-        start = curr.left[curr.left.length - 1];
-        deepPos = -1;
-      } else {
-        // we are in the left digit
-        final int l = curr.left.length, p = l + deepPos;
-        if(p > 0) {
-          // go to previous node in digit
-          --deepPos;
-          start = curr.left[p - 1];
-        } else {
-          // backtrack one level
-          trees[tTop] = null;
-          --tTop;
-          final Node<?, E>[] left = trees[tTop].left;
-          start = left[left.length - 1];
-          deepPos = -1;
-        }
-      }
-    }
-
-    Node<?, E> sub = start;
-    while(sub instanceof InnerNode) {
-      if(++nTop == nodes.length) {
-        final InnerNode<?, E>[] newNodes = new InnerNode[2 * nTop];
-        System.arraycopy(nodes, 0, newNodes, 0, nTop);
-        nodes = newNodes;
-        poss = Arrays.copyOf(poss, 2 * nTop);
-      }
-      nodes[nTop] = (InnerNode<?, E>) sub;
-      poss[nTop] = sub.arity() - 1;
-      sub = nodes[nTop].getSub(poss[nTop]);
-    }
-
-    leaf = (Node<E, E>) sub;
-    leafPos = sub.arity() - 1;
-    return leaf.getSub(leafPos);
-  }
-
-  @Override
-  public void set(final E e) {
-    throw new UnsupportedOperationException();
-  }
-
-  @Override
-  public void add(final E e) {
-    throw new UnsupportedOperationException();
-  }
-
-  @Override
-  public void remove() {
-    throw new UnsupportedOperationException();
-  }
-}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/fingertree/DeepTree.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/fingertree/DeepTree.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/fingertree/DeepTree.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/fingertree/DeepTree.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,858 @@
+package org.basex.query.util.fingertree;
+
+/**
+ * A <i>deep</i> node containing elements in the left and right digit and a sub-tree in
+ * the middle.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Leo Woerteler
+ *
+ * @param <N> node type
+ * @param <E> element type
+ */
+final class DeepTree<N, E> extends FingerTree<N, E> {
+  /** Preferred size of an inner node. */
+  private static final int NODE_SIZE = MAX_ARITY;
+  /** Left digit. */
+  final Node<N, E>[] left;
+  /** Size of the left digit, cached for speeding up indexing. */
+  final long leftSize;
+  /** Middle tree. */
+  final FingerTree<Node<N, E>, E> middle;
+  /** Right digit. */
+  final Node<N, E>[] right;
+
+  /** Size of this tree. */
+  final long size;
+
+  /**
+   * Constructor.
+   * @param left left digit
+   * @param leftSize size of the left digit
+   * @param middle middle tree
+   * @param right right digit
+   * @param size size of this tree
+   */
+  DeepTree(final Node<N, E>[] left, final long leftSize,
+      final FingerTree<Node<N, E>, E> middle, final Node<N, E>[] right, final long size) {
+    this.left = left;
+    this.leftSize = leftSize;
+    this.middle = middle;
+    this.right = right;
+    this.size = size;
+    assert left.length > 0 && right.length > 0
+        && size == leftSize + middle.size() + size(right);
+  }
+
+  /**
+   * Factory method calculating the size of the left digit.
+   * @param <N> node type
+   * @param <E> element type
+   * @param left left digit
+   * @param middle middle tree
+   * @param right right digit
+   * @param size size of this tree
+   * @return the deep node
+   */
+  static <N, E> DeepTree<N, E> get(final Node<N, E>[] left, final FingerTree<Node<N, E>, E> middle,
+      final Node<N, E>[] right, final long size) {
+    return new DeepTree<>(left, size(left), middle, right, size);
+  }
+
+  /**
+   * Factory method for deep nodes with an empty middle tree.
+   * @param <N> node type
+   * @param <E> element type
+   * @param left left digit
+   * @param leftSize size of the left sub-tree
+   * @param right right digit
+   * @param size size of this tree
+   * @return the deep node
+   */
+  static <N, E> DeepTree<N, E> get(final Node<N, E>[] left, final long leftSize,
+      final Node<N, E>[] right, final long size) {
+    return new DeepTree<>(left, leftSize, EmptyTree.<Node<N, E>, E>getInstance(), right, size);
+  }
+
+  /**
+   * Factory method for deep nodes with an empty middle tree calculating the size of the left digit.
+   * @param <N> node type
+   * @param <E> element type
+   * @param left left digit
+   * @param right right digit
+   * @param size size of this tree
+   * @return the deep node
+   */
+  static <N, E> DeepTree<N, E> get(final Node<N, E>[] left, final Node<N, E>[] right,
+      final long size) {
+    return new DeepTree<>(left, size(left), EmptyTree.<Node<N, E>, E>getInstance(), right, size);
+  }
+
+  /**
+   * Factory method for deep nodes calculating all cached sizes.
+   * @param <N> node type
+   * @param <E> element type
+   * @param left left digit
+   * @param middle middle sub-tree
+   * @param right right digit
+   * @return the deep node
+   */
+  static <N, E> DeepTree<N, E> get(final Node<N, E>[] left,
+      final FingerTree<Node<N, E>, E> middle, final Node<N, E>[] right) {
+    final long l = size(left), m = middle.size(), r = size(right);
+    return new DeepTree<>(left, l, middle, right, l + m + r);
+  }
+
+  /**
+   * Factory method for deep nodes with empty middle tree calculating all cached sizes.
+   * @param <N> node type
+   * @param <E> element type
+   * @param left left digit
+   * @param right right digit
+   * @return the deep node
+   */
+  static <N, E> DeepTree<N, E> get(final Node<N, E>[] left, final Node<N, E>[] right) {
+    final long l = size(left), r = size(right);
+    return new DeepTree<>(left, l, EmptyTree.<Node<N, E>, E>getInstance(), right, l + r);
+  }
+
+  @Override
+  public DeepTree<N, E> cons(final Node<N, E> fst) {
+    final long sz = fst.size();
+    if(left.length < MAX_DIGIT) {
+      final Node<N, E>[] newLeft = slice(left, -1, left.length);
+      newLeft[0] = fst;
+      return new DeepTree<>(newLeft, leftSize + sz, middle, right, size + sz);
+    }
+
+    final int ll = left.length, m = ll - NODE_SIZE;
+    final Node<N, E>[] newLeft = slice(left, -1, m), sub = slice(left, m, ll);
+    newLeft[0] = fst;
+    final FingerTree<Node<N, E>, E> mid = middle.cons(new InnerNode<>(sub));
+    return DeepTree.get(newLeft, mid, right, size + sz);
+  }
+
+  @Override
+  public DeepTree<N, E> snoc(final Node<N, E> lst) {
+    if(right.length < MAX_DIGIT) {
+      final Node<N, E>[] newRight = slice(right, 0, right.length + 1);
+      newRight[right.length] = lst;
+      return new DeepTree<>(left, leftSize, middle, newRight, size + lst.size());
+    }
+
+    final int rl = right.length, m = NODE_SIZE;
+    final Node<N, E>[] sub = slice(right, 0, m), newRight = slice(right, m, rl + 1);
+    newRight[rl - m] = lst;
+    final FingerTree<Node<N, E>, E> mid = middle.snoc(new InnerNode<>(sub));
+    return new DeepTree<>(left, leftSize, mid, newRight, size + lst.size());
+  }
+
+  @Override
+  public Node<N, E> head() {
+    return left[0];
+  }
+
+  @Override
+  public Node<N, E> last() {
+    return right[right.length - 1];
+  }
+
+  @Override
+  public FingerTree<N, E> init() {
+    final long newSize = size - right[right.length - 1].size();
+
+    if(right.length > 1) {
+      // right digit is safe, just shrink it
+      return new DeepTree<>(left, leftSize, middle, slice(right, 0, right.length - 1), newSize);
+    }
+
+    if(middle.isEmpty()) {
+      // middle tree empty, make a tree from the left list
+      if(left.length == 1) return new SingletonTree<>(left[0]);
+
+      final int mid = left.length / 2;
+      return DeepTree.get(slice(left, 0, mid), slice(left, mid, left.length), newSize);
+    }
+
+    // extract values for the right digit from the middle
+    final InnerNode<N, E> last = (InnerNode<N, E>) middle.last();
+    return new DeepTree<>(left, leftSize, middle.init(), last.children, newSize);
+  }
+
+  @Override
+  public FingerTree<N, E> tail() {
+    final long fstSize = left[0].size(),  newSize = size - fstSize;
+
+    if(left.length > 1) {
+      // left digit is safe, just shrink it
+      final Node<N, E>[] newLeft = slice(left, 1, left.length);
+      return new DeepTree<>(newLeft, leftSize - fstSize, middle, right, newSize);
+    }
+
+    if(middle.isEmpty()) {
+      // middle tree empty, make a tree from the right list
+      if(right.length == 1) return new SingletonTree<>(right[0]);
+
+      final int mid = right.length / 2;
+      return DeepTree.get(slice(right, 0, mid), slice(right, mid, right.length), newSize);
+    }
+
+    // extract values for the left digit from the middle
+    final InnerNode<N, E> head = (InnerNode<N, E>) middle.head();
+    return new DeepTree<>(head.children, head.size(), middle.tail(), right, newSize);
+  }
+
+  @Override
+  public long size() {
+    return this.size;
+  }
+
+  @Override
+  public DeepTree<N, E> concat(final Node<N, E>[] nodes, final long sz,
+      final FingerTree<N, E> other) {
+    final DeepTree<N, E> lft = (DeepTree<N, E>) addAll(nodes, sz, false);
+    if(!(other instanceof DeepTree)) return other.isEmpty() ? lft : lft.snoc(other.head());
+
+    final DeepTree<N, E> rght = (DeepTree<N, E>) other;
+    final Node<N, E>[] as = lft.right, bs = rght.left;
+    final int l = as.length, n = l + bs.length, k = (n + MAX_ARITY - 1) / MAX_ARITY;
+    @SuppressWarnings("unchecked")
+    final Node<Node<N, E>, E>[] out = new Node[k];
+    for(int i = 0, p = 0; i < k; i++) {
+      final int rem = k - i, curr = (n - p + rem - 1) / rem;
+      @SuppressWarnings("unchecked")
+      final Node<N, E>[] ch = new Node[curr];
+      final int inL = l - p;
+      if(curr <= inL) {
+        System.arraycopy(as, p, ch, 0, curr);
+      } else if(inL > 0) {
+        System.arraycopy(as, p, ch, 0, inL);
+        System.arraycopy(bs, 0, ch, inL, curr - inL);
+      } else {
+        System.arraycopy(bs, -inL, ch, 0, curr);
+      }
+      out[i] = new InnerNode<>(ch);
+      p += curr;
+    }
+
+    final long inMid = lft.rightSize() + rght.leftSize;
+    final FingerTree<Node<N, E>, E> newMid = lft.middle.concat(out, inMid, rght.middle);
+    final long newSize = lft.leftSize + newMid.size() + rght.rightSize();
+    return new DeepTree<>(lft.left, lft.leftSize, newMid, rght.right, newSize);
+  }
+
+  @Override
+  public FingerTree<N, E> reverse() {
+    final int l = left.length, r = right.length;
+    @SuppressWarnings("unchecked")
+    final Node<N, E>[] newLeft = new Node[r], newRight = new Node[l];
+    for(int i = 0; i < r; i++) newLeft[i] = right[r - 1 - i].reverse();
+    for(int i = 0; i < l; i++) newRight[i] = left[l - 1 - i].reverse();
+    return new DeepTree<>(newLeft, rightSize(), middle.reverse(), newRight, size);
+  }
+
+  @Override
+  public FingerTree<N, E> insert(final long pos, final E val) {
+    if(pos <= leftSize) {
+      // insert into left digit
+      int i = 0;
+      long p = pos;
+      for(;; i++) {
+        final long sub = left[i].size();
+        if(p <= sub) break;
+        p -= sub;
+      }
+
+      final int ll = left.length;
+      final Node<N, E> l = i > 0 ? left[i - 1] : null, r = i + 1 < ll ? left[i + 1] : null;
+      @SuppressWarnings("unchecked")
+      final Node<N, E>[] siblings = new Node[] { l, null, r, null };
+      if(!left[i].insert(siblings, p, val)) {
+        // no split
+        final Node<N, E>[] newLeft = left.clone();
+        if(i > 0) newLeft[i - 1] = siblings[0];
+        newLeft[i] = siblings[1];
+        if(i + 1 < ll) newLeft[i + 1] = siblings[2];
+        return new DeepTree<>(newLeft, leftSize + 1, middle, right, size + 1);
+      }
+
+      // node was split
+      @SuppressWarnings("unchecked")
+      final Node<N, E>[] temp = new Node[ll + 1];
+      if(i > 0) {
+        System.arraycopy(left, 0, temp, 0, i - 1);
+        temp[i - 1] = siblings[0];
+      }
+      temp[i] = siblings[1];
+      temp[i + 1] = siblings[2];
+      if(i + 1 < ll) {
+        temp[i + 2] = siblings[3];
+        System.arraycopy(left, i + 2, temp, i + 3, ll - i - 2);
+      }
+      if(ll < MAX_DIGIT) return new DeepTree<>(temp, leftSize + 1, middle, right, size + 1);
+
+      // digit has to be split
+      final int m = temp.length - NODE_SIZE;
+      final Node<N, E>[] newLeft = slice(temp, 0, m), ch = slice(temp, m, temp.length);
+      return DeepTree.get(newLeft, middle.cons(new InnerNode<>(ch)), right, size + 1);
+    }
+
+    long p = pos - leftSize;
+    final long midSize = middle.size();
+    if(p < midSize) return new DeepTree<>(left, leftSize, middle.insert(p, val), right, size + 1);
+
+    // insert into right digit
+    p -= midSize;
+    int i = 0;
+    for(;; i++) {
+      final long sub = right[i].size();
+      if(p <= sub) break;
+      p -= sub;
+    }
+
+    final int rl = right.length;
+    final Node<N, E> l = i > 0 ? right[i - 1] : null, r = i + 1 < rl ? right[i + 1] : null;
+    @SuppressWarnings("unchecked")
+    final Node<N, E>[] siblings = new Node[] { l, null, r, null };
+    if(!right[i].insert(siblings, p, val)) {
+      // no split
+      final Node<N, E>[] newRight = right.clone();
+      if(i > 0) newRight[i - 1] = siblings[0];
+      newRight[i] = siblings[1];
+      if(i + 1 < rl) newRight[i + 1] = siblings[2];
+      return new DeepTree<>(left, leftSize, middle, newRight, size + 1);
+    }
+
+    // node was split
+    @SuppressWarnings("unchecked")
+    final Node<N, E>[] temp = new Node[rl + 1];
+    if(i > 0) {
+      System.arraycopy(right, 0, temp, 0, i - 1);
+      temp[i - 1] = siblings[0];
+    }
+    temp[i] = siblings[1];
+    temp[i + 1] = siblings[2];
+    if(i + 1 < rl) {
+      temp[i + 2] = siblings[3];
+      System.arraycopy(right, i + 2, temp, i + 3, rl - i - 2);
+    }
+    if(right.length < MAX_DIGIT) return new DeepTree<>(left, leftSize, middle, temp, size + 1);
+
+    // digit has to be split
+    final int m = NODE_SIZE;
+    final Node<N, E>[] ch = slice(temp, 0, m), newRight = slice(temp, m, temp.length);
+    return new DeepTree<>(left, leftSize, middle.snoc(new InnerNode<>(ch)), newRight, size + 1);
+  }
+
+  @Override
+  public TreeSlice<N, E> remove(final long pos) {
+    if(pos < leftSize) return new TreeSlice<>(removeLeft(pos));
+    final long rightStart = leftSize + middle.size();
+    if(pos >= rightStart) return new TreeSlice<>(removeRight(pos - rightStart));
+
+    final TreeSlice<Node<N, E>, E> slice = middle.remove(pos - leftSize);
+    if(slice.isTree()) {
+      // no underflow
+      final FingerTree<Node<N, E>, E> newMiddle = slice.getTree();
+      return slice.setTree(new DeepTree<>(left, leftSize, newMiddle, right, size - 1));
+    }
+
+    // middle tree had an underflow, one sub-node left
+    final Node<N, E> node = (Node<N, E>) ((PartialInnerNode<N, E>) slice.getPartial()).sub;
+
+    // try to extend the smaller digit
+    if(left.length < right.length) {
+      // merge into left digit
+      final Node<N, E>[] newLeft = slice(left, 0, left.length + 1);
+      newLeft[left.length] = node;
+      return slice.setTree(DeepTree.get(newLeft, leftSize + node.size(), right, size - 1));
+    }
+
+    if(right.length < MAX_DIGIT) {
+      // merge into right digit
+      final Node<N, E>[] newRight = slice(right, -1, right.length);
+      newRight[0] = node;
+      return slice.setTree(DeepTree.get(left, leftSize, newRight, size - 1));
+    }
+
+    // redistribute the nodes
+    final int n = 2 * MAX_DIGIT + 1, ll = (n - NODE_SIZE) / 2;
+    @SuppressWarnings("unchecked")
+    final Node<N, E>[] newLeft = slice(left, 0, ll), ch = new Node[NODE_SIZE];
+    final int inL = left.length - ll, inR = NODE_SIZE - inL - 1;
+    System.arraycopy(left, ll, ch, 0, inL);
+    ch[inL] = node;
+    System.arraycopy(right, 0, ch, inL + 1, inR);
+    final Node<N, E>[] newRight = slice(right, inR, MAX_DIGIT);
+    final Node<Node<N, E>, E> newMid = new InnerNode<>(ch);
+    return slice.setTree(DeepTree.get(newLeft, new SingletonTree<>(newMid), newRight, size - 1));
+  }
+
+  /**
+   * Remove an element from the left digit.
+   * @param pos position inside the left digit
+   * @return resulting tree
+   */
+  private FingerTree<N, E> removeLeft(final long pos) {
+    if(left.length > 1) {
+      // left digit cannot underflow, just delete the element
+      return new DeepTree<>(remove(left, pos), leftSize - 1, middle, right, size - 1);
+    }
+
+    // singleton digit might underflow
+    final Node<N, E> node = left[0];
+
+    if(!middle.isEmpty()) {
+      // next node for balancing is in middle tree
+      final InnerNode<N, E> head = (InnerNode<N, E>) middle.head();
+      final Node<N, E> first = head.getSub(0);
+      final NodeLike<N, E>[] rem = node.remove(null, first, pos);
+      final Node<N, E> newNode = (Node<N, E>) rem[1], newFirst = (Node<N, E>) rem[2];
+
+      if(newNode == null) {
+        // nodes were merged
+        final Node<N, E>[] newLeft = head.children.clone();
+        newLeft[0] = newFirst;
+        return DeepTree.get(newLeft, middle.tail(), right, size - 1);
+      }
+
+      @SuppressWarnings("unchecked")
+      final Node<N, E>[] newLeft = new Node[] { newNode };
+
+      if(newFirst != first) {
+        // nodes were balanced
+        final FingerTree<Node<N, E>, E> newMid = middle.replaceHead(head.replaceFirst(newFirst));
+        return new DeepTree<>(newLeft, newNode.size(), newMid, right, size - 1);
+      }
+
+      // no changes to this tree's structure
+      return new DeepTree<>(newLeft, newNode.size(), middle, right, size - 1);
+    }
+
+    // potentially balance with right digit
+    final NodeLike<N, E>[] rem = node.remove(null, right[0], pos);
+    final Node<N, E> newNode = (Node<N, E>) rem[1], newFirstRight = (Node<N, E>) rem[2];
+
+    if(newNode == null) {
+      // nodes were merged
+      if(right.length == 1) return new SingletonTree<>(newFirstRight);
+      final int mid = right.length / 2;
+      final Node<N, E>[] newLeft = slice(right, 0, mid);
+      newLeft[0] = newFirstRight;
+      return DeepTree.get(newLeft, middle, slice(right, mid, right.length), size - 1);
+    }
+
+    // structure does not change
+    @SuppressWarnings("unchecked")
+    final Node<N, E>[] newLeft = new Node[] { newNode };
+
+    if(newFirstRight == right[0]) {
+      // right digit stays the same
+      return new DeepTree<>(newLeft, newLeft[0].size(), middle, right, size - 1);
+    }
+
+    // adapt the right digit
+    final Node<N, E>[] newRight = right.clone();
+    newRight[0] = newFirstRight;
+    return new DeepTree<>(newLeft, newNode.size(), middle, newRight, size - 1);
+  }
+
+  /**
+   * Remove an element from the right digit.
+   * @param pos position inside the right digit
+   * @return resulting tree
+   */
+  private FingerTree<N, E> removeRight(final long pos) {
+    if(right.length > 1) {
+      // right digit cannot underflow, just delete the element
+      return new DeepTree<>(left, leftSize, middle, remove(right, pos), size - 1);
+    }
+
+    // singleton digit might underflow
+    final Node<N, E> node = right[0];
+
+    if(!middle.isEmpty()) {
+      // potentially balance with middle tree
+      final InnerNode<N, E> last = (InnerNode<N, E>) middle.last();
+      final Node<N, E> lastSub = last.getSub(last.arity() - 1);
+      final NodeLike<N, E>[] rem = node.remove(lastSub, null, pos);
+      final Node<N, E> newLastSub = (Node<N, E>) rem[0], newNode = (Node<N, E>) rem[1];
+
+      if(newNode == null) {
+        // nodes were merged
+        final Node<N, E>[] newRight = last.children.clone();
+        newRight[newRight.length - 1] = newLastSub;
+        return new DeepTree<>(left, leftSize, middle.init(), newRight, size - 1);
+      }
+
+      @SuppressWarnings("unchecked")
+      final Node<N, E>[] newRight = new Node[] { newNode };
+
+      // replace last node in middle tree
+      final Node<Node<N, E>, E> newLast = last.replaceLast(newLastSub);
+      return new DeepTree<>(left, leftSize, middle.replaceLast(newLast), newRight, size - 1);
+    }
+
+    // balance with left digit
+    final Node<N, E> lastLeft = left[left.length - 1];
+    final NodeLike<N, E>[] rem = node.remove(lastLeft, null, pos);
+    final Node<N, E> newLastLeft = (Node<N, E>) rem[0], newNode = (Node<N, E>) rem[1];
+    if(newNode == null) {
+      // nodes were merged
+      if(left.length == 1) {
+        // only one node left
+        return new SingletonTree<>(newLastLeft);
+      }
+
+      @SuppressWarnings("unchecked")
+      final Node<N, E>[] newRight = new Node[] { newLastLeft };
+      return DeepTree.get(slice(left, 0, left.length - 1), newRight, size - 1);
+    }
+
+    @SuppressWarnings("unchecked")
+    final Node<N, E>[] newRight = new Node[] { newNode };
+
+    if(newLastLeft == lastLeft) {
+      // deletion could be absorbed
+      return DeepTree.get(left, leftSize, newRight, size - 1);
+    }
+
+    // adapt the left digit
+    final Node<N, E>[] newLeft = left.clone();
+    newLeft[newLeft.length - 1] = newLastLeft;
+    return DeepTree.get(newLeft, newRight, size - 1);
+  }
+
+  /**
+   * Deletes an element from the given digit containing at least two nodes.
+   * @param <N> node type
+   * @param <E> element type
+   * @param arr array of nodes
+   * @param pos deletion position
+   * @return new digit
+   */
+  private static <N, E> Node<N, E>[] remove(final Node<N, E>[] arr, final long pos) {
+    int i = 0;
+    long off = pos;
+    Node<N, E> node;
+    for(;;) {
+      node = arr[i];
+      final long nodeSize = node.size();
+      if(off < nodeSize) break;
+      off -= nodeSize;
+      i++;
+    }
+
+    final int n = arr.length;
+    final NodeLike<N, E>[] res = arr[i].remove(
+        i == 0 ? null : arr[i - 1], i == n - 1 ? null : arr[i + 1], off);
+    final Node<N, E> l = (Node<N, E>) res[0], m = (Node<N, E>) res[1], r = (Node<N, E>) res[2];
+    if(m != null) {
+      // same number of nodes
+      final Node<N, E>[] out = arr.clone();
+      if(i > 0) out[i - 1] = l;
+      out[i] = m;
+      if(i < n - 1) out[i + 1] = r;
+      return out;
+    }
+
+    // the node was merged
+    @SuppressWarnings("unchecked")
+    final Node<N, E>[] out = new Node[n - 1];
+    if(i > 0) {
+      // nodes to the left
+      System.arraycopy(arr, 0, out, 0, i - 1);
+      out[i - 1] = l;
+    }
+
+    if(i < n - 1) {
+      // nodes to the right
+      out[i] = r;
+      System.arraycopy(arr, i + 2, out, i + 1, n - i - 2);
+    }
+
+    return out;
+  }
+
+  @Override
+  public TreeSlice<N, E> slice(final long from, final long len) {
+    if(from == 0 && len == size) return new TreeSlice<>(this);
+    final long midSize = middle.size(), rightOff = leftSize + midSize;
+
+    final long inLeft = from + len <= leftSize ? len : from < leftSize ? leftSize - from : 0;
+    final long inRight = from >= rightOff ? len : from + len > rightOff ? from + len - rightOff : 0;
+
+    @SuppressWarnings("unchecked")
+    final NodeLike<N, E>[] buffer = new NodeLike[2 * MAX_DIGIT + 1];
+    int inBuffer = splitDigit(left, from, inLeft, buffer, 0);
+    if(inLeft == len) {
+      final int n = inBuffer;
+      if(n == 1) return new TreeSlice<>(buffer[0]);
+      final int mid1 = n / 2;
+      final Node<N, E>[] ls = slice(buffer, 0, mid1), rs = slice(buffer, mid1, n);
+      return new TreeSlice<>(DeepTree.get(ls, rs, len));
+    }
+
+    final long inMiddle = len - inLeft - inRight;
+    final FingerTree<Node<N, E>, E> mid;
+    final TreeSlice<Node<N, E>, E> slice;
+    if(inMiddle == 0) {
+      mid = EmptyTree.getInstance();
+      slice = new TreeSlice<>(mid);
+    } else {
+      final long midOff = from <= leftSize ? 0 : from - leftSize;
+      slice = middle.slice(midOff, inMiddle);
+      if(!slice.isTree()) {
+        final NodeLike<N, E> sub = ((PartialInnerNode<N, E>) slice.getPartial()).sub;
+        inBuffer = sub.append(buffer, inBuffer);
+        mid = EmptyTree.getInstance();
+      } else {
+        mid = slice.getTree();
+      }
+    }
+
+    final long rightFrom = from < rightOff ? 0 : from - rightOff;
+    if(mid.isEmpty()) {
+      inBuffer = splitDigit(right, rightFrom, inRight, buffer, inBuffer);
+      return slice.setNodes(buffer, inBuffer, len);
+    }
+
+    final FingerTree<Node<N, E>, E> mid2;
+    if(inBuffer > 1 || buffer[0] instanceof Node) {
+      mid2 = mid;
+    } else {
+      final InnerNode<N, E> head = (InnerNode<N, E>) mid.head();
+      final int k = head.arity();
+      inBuffer = head.getSub(0).append(buffer, inBuffer);
+      for(int i = 1; i < k; i++) buffer[inBuffer++] = head.getSub(i);
+      mid2 = mid.tail();
+    }
+
+    if(mid2.isEmpty()) {
+      inBuffer = splitDigit(right, rightFrom, inRight, buffer, inBuffer);
+      return slice.setNodes(buffer, inBuffer, len);
+    }
+
+    final Node<N, E>[] newLeft = slice(buffer, 0, inBuffer);
+    inBuffer = splitDigit(right, rightFrom, inRight, buffer, 0);
+
+    final FingerTree<Node<N, E>, E> mid3;
+    final Node<N, E>[] newRight;
+    if(inBuffer == 0) {
+      mid3 = mid2.init();
+      newRight = ((InnerNode<N, E>) mid2.last()).children;
+    } else if(inBuffer > 1 || buffer[0] instanceof Node) {
+      mid3 = mid2;
+      newRight = slice(buffer, 0, inBuffer);
+    } else {
+      final NodeLike<N, E> partial = buffer[0];
+      final InnerNode<N, E> last = (InnerNode<N, E>) mid2.last();
+      final int k = last.arity();
+      for(int i = 0; i < k; i++) buffer[i] = last.getSub(i);
+      inBuffer = partial.append(buffer, k);
+      mid3 = mid2.init();
+      newRight = slice(buffer, 0, inBuffer);
+    }
+
+    return slice.setTree(DeepTree.get(newLeft, mid3, newRight, len));
+  }
+
+  /**
+   * Creates a tree slice from a digit.
+   * @param <N> node type
+   * @param <E> element type
+   * @param nodes the digit
+   * @param from element offset
+   * @param len number of elements
+   * @param buffer buffer to insert the node slice into
+   * @param inBuffer initial number of nodes in the buffer
+   * @return the slice
+   */
+  private static <N, E> int splitDigit(final Node<N, E>[] nodes, final long from,
+      final long len, final NodeLike<N, E>[] buffer, final int inBuffer) {
+    if(len <= 0) return inBuffer;
+
+    // find the first sub-node containing used elements
+    int firstPos = 0;
+    long firstOff = from;
+    Node<N, E> first = nodes[0];
+    long firstSize = first.size();
+    while(firstOff >= firstSize) {
+      firstOff -= firstSize;
+      first = nodes[++firstPos];
+      firstSize = first.size();
+    }
+
+    // firstOff < firstSize
+    final long inFirst = firstSize - firstOff;
+    if(inFirst >= len) {
+      // everything in first sub-node
+      final NodeLike<N, E> part = len == firstSize ? first : first.slice(firstOff, len);
+      return part.append(buffer, inBuffer);
+    }
+
+    final NodeLike<N, E> firstSlice = firstOff == 0 ? first : first.slice(firstOff, inFirst);
+    int numMerged = firstSlice.append(buffer, inBuffer);
+
+    int pos = firstPos;
+    long remaining = len - inFirst;
+    while(remaining > 0) {
+      final Node<N, E> curr = nodes[++pos];
+      final long currSize = curr.size();
+      final NodeLike<N, E> slice = remaining >= currSize ? curr : curr.slice(0, remaining);
+      numMerged = slice.append(buffer, numMerged);
+      remaining -= currSize;
+    }
+
+    return numMerged;
+  }
+
+  /**
+   * Calculates the size of the right digit.
+   * @return number of elements in the right digit
+   */
+  private long rightSize() {
+    return size - leftSize - middle.size();
+  }
+
+  @Override
+  FingerTree<N, E> addAll(final Node<N, E>[] nodes, final long sz, final boolean appendLeft) {
+    final int k = nodes.length;
+    if(k == 0) return this;
+    if(k == 1) return appendLeft ? cons(nodes[0]) : snoc(nodes[0]);
+
+    if(appendLeft) {
+      int l = k + left.length;
+      final Node<N, E>[] ls = slice(nodes, 0, l);
+      System.arraycopy(left, 0, ls, k, left.length);
+      if(l <= MAX_DIGIT) return DeepTree.get(ls, middle, right);
+
+      FingerTree<Node<N, E>, E> newMid = middle;
+      for(int rem = (l + MAX_ARITY - 1) / MAX_ARITY; rem > 1; rem--) {
+        final int curr = (l + rem - 1) / rem;
+        newMid = newMid.cons(new InnerNode<>(slice(ls, l - curr, l)));
+        l -= curr;
+      }
+
+      return DeepTree.get(slice(ls, 0, l), newMid, right);
+    }
+
+    final int r = right.length + k;
+    final Node<N, E>[] rs = slice(right, 0, r);
+    System.arraycopy(nodes, 0, rs, right.length, k);
+    if(k + right.length <= MAX_DIGIT) return DeepTree.get(left, middle, rs);
+
+    int i = 0;
+    FingerTree<Node<N, E>, E> newMid = middle;
+    for(int rem = (r + MAX_ARITY - 1) / MAX_ARITY; rem > 1; rem--) {
+      final int curr = (r - i + rem - 1) / rem;
+      newMid = newMid.snoc(new InnerNode<>(slice(rs, i, i + curr)));
+      i += curr;
+    }
+
+    return DeepTree.get(left, newMid, slice(rs, i, r));
+  }
+
+  @Override
+  public FingerTree<N, E> replaceHead(final Node<N, E> head) {
+    final long sizeDiff = head.size() - left[0].size();
+    final Node<N, E>[] newLeft = left.clone();
+    newLeft[0] = head;
+    return new DeepTree<>(newLeft, leftSize + sizeDiff, middle, right, size + sizeDiff);
+  }
+
+  @Override
+  public FingerTree<N, E> replaceLast(final Node<N, E> last) {
+    final int lst = right.length - 1;
+    final Node<N, E>[] newRight = right.clone();
+    newRight[lst] = last;
+    return new DeepTree<>(left, leftSize, middle, newRight, size + last.size()
+        - right[lst].size());
+  }
+
+  @Override
+  void toString(final StringBuilder sb, final int indent) {
+    for(int i = 0; i < indent; i++) sb.append("  ");
+    sb.append("Deep(").append(size).append(")[\n");
+
+    // left digit
+    for(int i = 0; i < indent + 1; i++) sb.append("  ");
+    sb.append("Left(").append(leftSize).append(")[\n");
+    for(final Node<N, E> e : left) {
+      toString(e, sb, indent + 2);
+      sb.append('\n');
+    }
+    for(int i = 0; i < indent + 1; i++) sb.append("  ");
+    sb.append("]\n");
+
+    // middle tree
+    middle.toString(sb, indent + 1);
+    sb.append('\n');
+
+    // right digit
+    for(int i = 0; i < indent + 1; i++) sb.append("  ");
+    sb.append("Right[\n");
+    for(final Node<N, E> e : right) {
+      toString(e, sb, indent + 2);
+      sb.append("\n");
+    }
+    for(int i = 0; i < indent + 1; i++) sb.append("  ");
+    sb.append("]\n");
+
+    for(int i = 0; i < indent; i++) sb.append("  ");
+    sb.append("]");
+  }
+
+  @Override
+  public long checkInvariants() {
+    if(left.length < 1 || left.length > MAX_DIGIT) throw new AssertionError(
+        "Wrong left digit length: " + left.length);
+    long sz = 0;
+    for(final Node<N, E> nd : left)
+      sz += nd.checkInvariants();
+    if(sz != leftSize) throw new AssertionError("Wrong leftSize: " + leftSize + " vs. "
+        + sz);
+    sz += middle.checkInvariants();
+    if(right.length < 1 || right.length > MAX_DIGIT) throw new AssertionError(
+        "Wrong right digit length: " + right.length);
+    for(final Node<N, E> nd : right)
+      sz += nd.checkInvariants();
+    if(sz != size) throw new AssertionError("Wrong size: " + size + " vs. " + sz);
+    return sz;
+  }
+
+  /**
+   * Calculates the size of a digit.
+   * @param <N> node type
+   * @param arr digit
+   * @return size
+   */
+  static <N extends Node<?, ?>> long size(final N[] arr) {
+    long size = 0;
+    for(final N o : arr)
+      size += o.size();
+    return size;
+  }
+
+  /**
+   * Returns an array containing the values at the indices {@code from} to {@code to - 1}
+   * in the given array. Its length is always {@code to - from}. If {@code from} is
+   * smaller than zero, the first {@code -from} entries in the resulting array are
+   * {@code null}. If {@code to > arr.length} then the last {@code to - arr.length}
+   * entries are {@code null}.
+   * @param <N> node type
+   * @param <E> element type
+   * @param arr input array
+   * @param from first index, inclusive (may be negative)
+   * @param to last index, exclusive (may be greater than {@code arr.length})
+   * @return resulting array
+   */
+  static <N, E> Node<N, E>[] slice(final NodeLike<N, E>[] arr, final int from, final int to) {
+    @SuppressWarnings("unchecked")
+    final Node<N, E>[] out = new Node[to - from];
+    final int in0 = Math.max(0, from), in1 = Math.min(to, arr.length);
+    final int out0 = Math.max(-from, 0);
+    System.arraycopy(arr, in0, out, out0, in1 - in0);
+    return out;
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/fingertree/Empty.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/fingertree/Empty.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/fingertree/Empty.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/fingertree/Empty.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,129 +0,0 @@
-package org.basex.query.util.fingertree;
-
-import java.util.*;
-
-/**
- * An empty finger tree.
- *
- * @author BaseX Team 2005-15, BSD License
- * @author Leo Woerteler
- *
- * @param <N> node type
- * @param <E> element type
- */
-final class Empty<N, E> extends FingerTree<N, E> {
-  /** The empty finger tree. */
-  static final Empty<?, ?> INSTANCE = new Empty<>();
-
-  /**
-   * Getter for the empty finger tree.
-   * @param <N> node type
-   * @param <E> element type
-   * @return empty tree
-   */
-  @SuppressWarnings("unchecked")
-  static <N, E> Empty<N, E> getInstance() {
-    return (Empty<N, E>) INSTANCE;
-  }
-
-  /** Hidden constructor. */
-  private Empty() {
-  }
-
-  @Override
-  public FingerTree<N, E> cons(final Node<N, E> fst) {
-    return new Single<>(fst);
-  }
-
-  @Override
-  public FingerTree<N, E> snoc(final Node<N, E> lst) {
-    return new Single<>(lst);
-  }
-
-  @Override
-  public Node<N, E> head() {
-    throw new NoSuchElementException();
-  }
-
-  @Override
-  public Node<N, E> last() {
-    throw new NoSuchElementException();
-  }
-
-  @Override
-  public FingerTree<N, E> init() {
-    throw new IllegalStateException("Empty Tree");
-  }
-
-  @Override
-  public FingerTree<N, E> tail() {
-    throw new IllegalStateException("Empty Tree");
-  }
-
-  @Override
-  public long size() {
-    return 0;
-  }
-
-  @Override
-  public FingerTree<N, E> concat(final Node<N, E>[] nodes, final FingerTree<N, E> other) {
-    return other.addAll(nodes, true);
-  }
-
-  @Override
-  public TreeSlice<N, E> slice(final long pos, final long len) {
-    if(pos == 0 && len == 0) return new TreeSlice<>(this);
-    throw new AssertionError("Empty sub-tree.");
-  }
-
-  @Override
-  public FingerTree<N, E> reverse() {
-    return this;
-  }
-
-  @Override
-  public FingerTree<N, E> insert(final long pos, final E val) {
-    throw new AssertionError("Empty sub-tree.");
-  }
-
-  @Override
-  public TreeSlice<N, E> remove(final long pos) {
-    throw new AssertionError("Empty sub-tree.");
-  }
-
-  @Override
-  public ListIterator<E> listIterator(final boolean reverse) {
-    return Collections.emptyListIterator();
-  }
-
-  @Override
-  public FingerTree<N, E> replaceHead(final Node<N, E> head) {
-    throw new AssertionError("Empty sub-tree.");
-  }
-
-  @Override
-  public FingerTree<N, E> replaceLast(final Node<N, E> last) {
-    throw new AssertionError("Empty sub-tree.");
-  }
-
-  @Override
-  void toString(final StringBuilder sb, final int indent) {
-    for(int i = 0; i < indent; i++) sb.append("  ");
-    sb.append("Empty[]");
-  }
-
-  @Override
-  public long checkInvariants() {
-    return 0;
-  }
-
-  @Override
-  public long[] sizes(final int depth) {
-    return new long[depth];
-  }
-
-  @Override
-  FingerTree<N, E> addAll(final Node<N, E>[] nodes, final boolean left) {
-    return buildTree(nodes, nodes.length, Deep.size(nodes));
-  }
-}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/fingertree/EmptyTree.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/fingertree/EmptyTree.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/fingertree/EmptyTree.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/fingertree/EmptyTree.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,120 @@
+package org.basex.query.util.fingertree;
+
+import java.util.*;
+
+/**
+ * An empty finger tree.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Leo Woerteler
+ *
+ * @param <N> node type
+ * @param <E> element type
+ */
+final class EmptyTree<N, E> extends FingerTree<N, E> {
+  /** The empty finger tree. */
+  static final EmptyTree<?, ?> INSTANCE = new EmptyTree<>();
+
+  /**
+   * Getter for the empty finger tree.
+   * @param <N> node type
+   * @param <E> element type
+   * @return empty tree
+   */
+  @SuppressWarnings("unchecked")
+  static <N, E> EmptyTree<N, E> getInstance() {
+    return (EmptyTree<N, E>) INSTANCE;
+  }
+
+  /** Hidden constructor. */
+  private EmptyTree() {
+  }
+
+  @Override
+  public FingerTree<N, E> cons(final Node<N, E> fst) {
+    return new SingletonTree<>(fst);
+  }
+
+  @Override
+  public FingerTree<N, E> snoc(final Node<N, E> lst) {
+    return new SingletonTree<>(lst);
+  }
+
+  @Override
+  public Node<N, E> head() {
+    throw new NoSuchElementException();
+  }
+
+  @Override
+  public Node<N, E> last() {
+    throw new NoSuchElementException();
+  }
+
+  @Override
+  public FingerTree<N, E> init() {
+    throw new IllegalStateException("Empty Tree");
+  }
+
+  @Override
+  public FingerTree<N, E> tail() {
+    throw new IllegalStateException("Empty Tree");
+  }
+
+  @Override
+  public long size() {
+    return 0;
+  }
+
+  @Override
+  public FingerTree<N, E> concat(final Node<N, E>[] nodes, final long sz,
+      final FingerTree<N, E> other) {
+    return other.addAll(nodes, sz, true);
+  }
+
+  @Override
+  public TreeSlice<N, E> slice(final long pos, final long len) {
+    if(pos == 0 && len == 0) return new TreeSlice<>(this);
+    throw new AssertionError("Empty sub-tree.");
+  }
+
+  @Override
+  public FingerTree<N, E> reverse() {
+    return this;
+  }
+
+  @Override
+  public FingerTree<N, E> insert(final long pos, final E val) {
+    throw new AssertionError("Empty sub-tree.");
+  }
+
+  @Override
+  public TreeSlice<N, E> remove(final long pos) {
+    throw new AssertionError("Empty sub-tree.");
+  }
+
+  @Override
+  public FingerTree<N, E> replaceHead(final Node<N, E> head) {
+    throw new AssertionError("Empty sub-tree.");
+  }
+
+  @Override
+  public FingerTree<N, E> replaceLast(final Node<N, E> last) {
+    throw new AssertionError("Empty sub-tree.");
+  }
+
+  @Override
+  void toString(final StringBuilder sb, final int indent) {
+    for(int i = 0; i < indent; i++) sb.append("  ");
+    sb.append("Empty[]");
+  }
+
+  @Override
+  public long checkInvariants() {
+    return 0;
+  }
+
+  @Override
+  FingerTree<N, E> addAll(final Node<N, E>[] nodes, final long sz, final boolean left) {
+    return buildTree(nodes, nodes.length, sz);
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/fingertree/FingerTreeBuilder.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/fingertree/FingerTreeBuilder.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/fingertree/FingerTreeBuilder.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/fingertree/FingerTreeBuilder.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,5 +1,7 @@
 package org.basex.query.util.fingertree;
 
+import java.util.*;
+
 /**
  * A builder for {@link FingerTree}s from leaf nodes.
  *
@@ -8,9 +10,10 @@
  *
  * @param <E> element type
  */
-public final class FingerTreeBuilder<E> {
+@SuppressWarnings("unchecked")
+public final class FingerTreeBuilder<E> implements Iterable<E> {
   /** The root node, {@code null} if the tree is empty. */
-  private BufferNode<E, E> root;
+  private Object root;
 
   /**
    * Checks if this builder is empty, i.e. if no leaf nodes were added to it.
@@ -27,8 +30,12 @@
   public void prepend(final Node<E, E> leaf) {
     if(root == null) {
       root = new BufferNode<>(leaf);
+    } else if(root instanceof BufferNode) {
+      ((BufferNode<E, E>) root).prepend(leaf);
     } else {
-      root.prepend(leaf);
+      final BufferNode<E, E> newRoot = new BufferNode<>((FingerTree<E, E>) root);
+      newRoot.prepend(leaf);
+      root = newRoot;
     }
   }
 
@@ -39,8 +46,12 @@
   public void append(final Node<E, E> leaf) {
     if(root == null) {
       root = new BufferNode<>(leaf);
+    } else if(root instanceof BufferNode) {
+      ((BufferNode<E, E>) root).append(leaf);
     } else {
-      root.append(leaf);
+      final BufferNode<E, E> newRoot = new BufferNode<>((FingerTree<E, E>) root);
+      newRoot.append(leaf);
+      root = newRoot;
     }
   }
 
@@ -52,8 +63,12 @@
     if(!tree.isEmpty()) {
       if(root == null) {
         root = new BufferNode<>(tree);
+      } else if(root instanceof BufferNode) {
+        ((BufferNode<E, E>) root).append(tree);
       } else {
-        root.append(tree);
+        final BufferNode<E, E> newRoot = new BufferNode<>((FingerTree<E, E>) root);
+        newRoot.append(tree);
+        root = newRoot;
       }
     }
   }
@@ -63,24 +78,28 @@
    * @return the resulting finger tree
    */
   public FingerTree<E, E> freeze() {
-    return root == null ? FingerTree.<E>empty() : root.freeze();
-  }
-
-  /**
-   * Writes the elements contained in this builder onto the given string builder.
-   * @param sb string builder
-   */
-  public void toString(final StringBuilder sb) {
-    if(root != null) root.toString(sb);
+    return root == null ? FingerTree.<E>empty() :
+      root instanceof BufferNode ? ((BufferNode<E, E>) root).freeze() : (FingerTree<E, E>) root;
   }
 
   @Override
   public String toString() {
     final StringBuilder sb = new StringBuilder(getClass().getSimpleName()).append('[');
-    toString(sb);
+    final Iterator<E> iter = iterator();
+    if(iter.hasNext()) {
+      sb.append(iter.next());
+      while(iter.hasNext()) sb.append(", ").append(iter.next());
+    }
     return sb.append(']').toString();
   }
 
+  @Override
+  public Iterator<E> iterator() {
+    if(root == null) return Collections.emptyIterator();
+    if(root instanceof FingerTree) return ((FingerTree<E, E>) root).iterator();
+    return new BufferNodeIterator<>((BufferNode<E, E>) root);
+  }
+
   /**
    * Node of the middle tree.
    *
@@ -88,17 +107,25 @@
    * @param <E> element type
    */
   private static class BufferNode<N, E> {
+    /** Size of inner nodes to create. */
+    private static final int NODE_SIZE = FingerTree.MAX_ARITY;
+    /** Maximum number of elements in a digit. */
+    private static final int MAX_DIGIT = NODE_SIZE + 1;
+    /** Maximum number of nodes in the digits. */
+    private static final int CAP = 2 * MAX_DIGIT;
     /** Ring buffer for nodes in the digits. */
-    @SuppressWarnings("unchecked")
-    final Node<N, E>[] nodes = new Node[8];
+    final Node<N, E>[] nodes = new Node[CAP];
     /** Number of elements in left digit. */
-    int l;
+    int inLeft;
     /** Position of middle between left and right digit in buffer. */
-    int m = 4;
+    int midPos = MAX_DIGIT;
     /** Number of elements in right digit. */
-    int r;
-    /** Root node of middle tree. */
-    BufferNode<Node<N, E>, E> sub;
+    int inRight;
+    /**
+     * Root node of middle tree, either a {@code FingerTree<Node<N, E>, E>} or a
+     * {@code BufferNode<Node<N, E>, E>}.
+     */
+    Object middle;
 
     /**
      * Constructs a buffered tree containing the given single node.
@@ -113,13 +140,13 @@
      * @param tree the tree to take the contents of
      */
     BufferNode(final FingerTree<N, E> tree) {
-      if(tree instanceof Single) {
-        prepend(((Single<N, E>) tree).elem);
+      if(tree instanceof SingletonTree) {
+        prepend(((SingletonTree<N, E>) tree).elem);
       } else {
-        final Deep<N, E> deep = (Deep<N, E>) tree;
+        final DeepTree<N, E> deep = (DeepTree<N, E>) tree;
         for(int i = deep.left.length; --i >= 0;) prepend(deep.left[i]);
         final FingerTree<Node<N, E>, E> mid = deep.middle;
-        if(!mid.isEmpty()) sub = new BufferNode<>(mid);
+        if(!mid.isEmpty()) middle = mid;
         for(final Node<N, E> node : deep.right) append(node);
       }
     }
@@ -129,26 +156,21 @@
      * @param node the node to add
      */
     void prepend(final Node<N, E> node) {
-      if(l < 4) {
-        nodes[(m - l + 7) & 7] = node;
-        l++;
-      } else if(sub == null && r < 4) {
-        m = (m + 7) & 7;
-        nodes[(m - l + 8) & 7] = node;
-        r++;
+      if(inLeft < MAX_DIGIT) {
+        nodes[(midPos - inLeft - 1 + CAP) % CAP] = node;
+        inLeft++;
+      } else if(middle == null && inRight < MAX_DIGIT) {
+        midPos = (midPos - 1 + CAP) % CAP;
+        nodes[(midPos - inLeft + CAP) % CAP] = node;
+        inRight++;
       } else {
-        final int l3 = (m + 7) & 7, l2 = (l3 + 7) & 7, l1 = (l2 + 7) & 7, l0 = (l1 + 7) & 7;
-        final Node<Node<N, E>, E> next = new InnerNode3<>(nodes[l1], nodes[l2], nodes[l3]);
-        nodes[l3] = nodes[l0];
-        nodes[l2] = node;
-        nodes[l1] = null;
-        nodes[l0] = null;
-        l = 2;
-        if(sub == null) {
-          sub = new BufferNode<>(next);
-        } else {
-          sub.prepend(next);
-        }
+        final int l = (midPos - inLeft + CAP) % CAP;
+        final Node<Node<N, E>, E> next = new InnerNode<>(copy(l + 1, inLeft - 1));
+        nodes[(midPos - 1 + CAP) % CAP] = nodes[l];
+        nodes[(midPos - 2 + CAP) % CAP] = node;
+        inLeft = 2;
+        if(middle == null) middle = new BufferNode<>(next);
+        else midBuffer().prepend(next);
       }
     }
 
@@ -157,26 +179,20 @@
      * @param node the node to add
      */
     void append(final Node<N, E> node) {
-      if(r < 4) {
-        nodes[(m + r) & 7] = node;
-        r++;
-      } else if(sub == null && l < 4) {
-        m = (m + 1) & 7;
-        nodes[(m + r - 1) & 7] = node;
-        l++;
+      if(inRight < MAX_DIGIT) {
+        nodes[(midPos + inRight) % CAP] = node;
+        inRight++;
+      } else if(middle == null && inLeft < MAX_DIGIT) {
+        midPos = (midPos + 1) % CAP;
+        nodes[(midPos + inRight - 1) % CAP] = node;
+        inLeft++;
       } else {
-        final int r0 = m, r1 = (r0 + 1) & 7, r2 = (r1 + 1) & 7, r3 = (r2 + 1) & 7;
-        final Node<Node<N, E>, E> next = new InnerNode3<>(nodes[r0], nodes[r1], nodes[r2]);
-        nodes[r0] = nodes[r3];
-        nodes[r1] = node;
-        nodes[r2] = null;
-        nodes[r3] = null;
-        r = 2;
-        if(sub == null) {
-          sub = new BufferNode<>(next);
-        } else {
-          sub.append(next);
-        }
+        final Node<Node<N, E>, E> next = new InnerNode<>(copy(midPos, inRight - 1));
+        nodes[midPos] = nodes[(midPos + inRight - 1) % CAP];
+        nodes[(midPos + 1) % CAP] = node;
+        inRight = 2;
+        if(middle == null) middle = new BufferNode<>(next);
+        else midBuffer().append(next);
       }
     }
 
@@ -185,53 +201,48 @@
      * @param tree finger tree to append
      */
     void append(final FingerTree<N, E> tree) {
-      if(!(tree instanceof Deep)) {
-        if(tree instanceof Single) append(((Single<N, E>) tree).elem);
+      if(!(tree instanceof DeepTree)) {
+        if(tree instanceof SingletonTree) append(((SingletonTree<N, E>) tree).elem);
         return;
       }
 
-      final Deep<N, E> deep = (Deep<N, E>) tree;
+      final DeepTree<N, E> deep = (DeepTree<N, E>) tree;
       final Node<N, E>[] ls = deep.left, rs = deep.right;
       final int ll = ls.length, rl = rs.length;
       final FingerTree<Node<N, E>, E> mid = deep.middle;
 
       if(mid.isEmpty()) {
+        // add digits
         for(int i = 0; i < ll; i++) append(ls[i]);
         for(int i = 0; i < rl; i++) append(rs[i]);
-      } else if(sub == null) {
-        final int n = l + r;
-        @SuppressWarnings("unchecked")
+      } else if(middle == null) {
+        // cache previous contents and re-add them afterwards
+        final int n = inLeft + inRight;
         final Node<N, E>[] buff = new Node[n + ll];
-        for(int i = 0; i < n; i++) buff[i] = nodes[(m - l + i + 8) & 7];
+        copyInto(midPos - inLeft, buff, 0, n);
         System.arraycopy(ls, 0, buff, n, ll);
-        l = r = 0;
-        sub = new BufferNode<>(mid);
+        inLeft = inRight = 0;
+        middle = mid;
         for(int i = buff.length; --i >= 0;) prepend(buff[i]);
         for(int i = 0; i < rl; i++) append(rs[i]);
       } else {
-        final int k = r + ll;
-        @SuppressWarnings("unchecked")
-        final Node<N, E>[] buff = new Node[k];
-        for(int i = 0; i < r; i++) {
-          final int j = (m + i) & 7;
-          buff[i] = nodes[j];
-          nodes[j] = null;
-        }
-        System.arraycopy(ls, 0, buff, r, ll);
-        r = 0;
-
-        for(int i = 0; i < k;) {
-          final int rest = k - i;
-          if(rest > 4 || rest == 3) {
-            sub.append(new InnerNode3<>(buff[i], buff[i + 1], buff[i + 2]));
-            i += 3;
-          } else {
-            sub.append(new InnerNode2<>(buff[i], buff[i + 1]));
-            i += 2;
-          }
+        // inner digits have to be merged
+        final int n = inRight + ll;
+        final Node<N, E>[] buff = new Node[n];
+        copyInto(midPos, buff, 0, inRight);
+        System.arraycopy(ls, 0, buff, inRight, ll);
+        inRight = 0;
+        for(int k = (n + NODE_SIZE - 1) / NODE_SIZE, p = 0; k > 0; k--) {
+          final int inNode = (n - p + k - 1) / k;
+          final Node<N, E>[] out = new Node[inNode];
+          System.arraycopy(buff, p, out, 0, inNode);
+          final Node<Node<N, E>, E> sub = new InnerNode<>(out);
+          if(middle == null) middle = new BufferNode<>(sub);
+          else midBuffer().append(sub);
+          p += inNode;
         }
-
-        sub.append(mid);
+        if(middle == null) middle = mid;
+        else midBuffer().append(mid);
         for(int i = 0; i < rl; i++) append(rs[i]);
       }
     }
@@ -241,44 +252,155 @@
      * @return the finger tree
      */
     FingerTree<N, E> freeze() {
-      final int n = l + r;
-      if(n == 1) return new Single<>(nodes[(m + r + 7) & 7]);
-      final int a = sub == null ? n / 2 : l, b = n - a;
-      @SuppressWarnings("unchecked")
-      final Node<N, E>[] left = new Node[a], right = new Node[b];
-      final int lOff = m - l + 8, rOff = lOff + a;
-      for(int i = 0; i < a; i++) left[i] = nodes[(lOff + i) & 7];
-      for(int i = 0; i < b; i++) right[i] = nodes[(rOff + i) & 7];
-      return sub == null ? Deep.get(left, right) : Deep.get(left, sub.freeze(), right);
+      final int n = inLeft + inRight;
+      if(n == 1) return new SingletonTree<>(nodes[(midPos + inRight - 1 + CAP) % CAP]);
+      final int a = middle == null ? n / 2 : inLeft, l = midPos - inLeft;
+      final Node<N, E>[] left = copy(l, a), right = copy(l + a, n - a);
+      if(middle == null) return DeepTree.get(left, right);
+
+      if(middle instanceof FingerTree) {
+        final FingerTree<Node<N, E>, E> tree = (FingerTree<Node<N, E>, E>) middle;
+        return DeepTree.get(left, tree, right);
+      }
+
+      final BufferNode<Node<N, E>, E> buffer = (BufferNode<Node<N, E>, E>) middle;
+      return DeepTree.get(left, buffer.freeze(), right);
     }
 
     /**
-     * Writes the elements contained in this node onto the given string builder.
-     * @param sb string builder
-     */
-    void toString(final StringBuilder sb) {
-      boolean first = true;
-      for(int i = 0; i < l; i++) {
-        final Node<N, E> node = nodes[(m - l + i + 8) & 7];
-        for(final E elem : node) {
-          if(first) first = false;
-          else sb.append(", ");
-          sb.append(elem);
-        }
+     * Returns the node at the given position in this node's ring buffer.
+     * @param pos position
+     * @return node at that position
+     */
+    Node<N, E> get(final int pos) {
+      return nodes[(((midPos + pos) % CAP) + CAP) % CAP];
+    }
+
+    /**
+     * Returns the middle tree as a buffer node.
+     * @return middle buffer node
+     */
+    private BufferNode<Node<N, E>, E> midBuffer() {
+      if(middle == null) return null;
+      if(middle instanceof BufferNode) return (BufferNode<Node<N, E>, E>) middle;
+      final BufferNode<Node<N, E>, E> mid = new BufferNode<>((FingerTree<Node<N, E>, E>) middle);
+      middle = mid;
+      return mid;
+    }
+
+    /**
+     * Copies the elements in the given range from the ring buffer into an array.
+     * @param start start of the range
+     * @param len length of the range
+     * @return array containing all nodes in the range
+     */
+    private Node<N, E>[] copy(final int start, final int len) {
+      final Node<N, E>[] out = new Node[len];
+      copyInto(start, out, 0, len);
+      return out;
+    }
+
+    /**
+     * Copies the nodes in the given range of the ring buffer into the given array.
+     * @param start start position of the range in the ring buffer
+     * @param arr output array
+     * @param pos start position in the output array
+     * @param len length of the range
+     */
+    private void copyInto(final int start, final Node<N, E>[] arr, final int pos, final int len) {
+      final int p = ((start % CAP) + CAP) % CAP, k = CAP - p;
+      if(len <= k) {
+        System.arraycopy(nodes, p, arr, pos, len);
+      } else {
+        System.arraycopy(nodes, p, arr, pos, k);
+        System.arraycopy(nodes, 0, arr, pos + k, len - k);
       }
-      if(sub != null) {
-        if(first) first = false;
-        else sb.append(", ");
-        sub.toString(sb);
-      }
-      for(int i = 0; i < r; i++) {
-        final Node<N, E> node = nodes[(m + i) & 7];
-        for(final E elem : node) {
-          if(first) first = false;
-          else sb.append(", ");
-          sb.append(elem);
+    }
+  }
+
+  /**
+   * Iterator over the elements in this builder.
+   * @param <E> element type
+   */
+  private static class BufferNodeIterator<E> implements Iterator<E> {
+    /** Stack of buffer nodes. */
+    private BufferNode<?, E>[] stack = new BufferNode[8];
+    /** Stack of position inside the buffer nodes. */
+    private int[] poss = new int[8];
+    /** Stack top. */
+    private int top;
+    /** Iterator over the current tree node. */
+    private Iterator<E> sub;
+
+    /**
+     * Constructor.
+     * @param root buffer node
+     */
+    BufferNodeIterator(final BufferNode<E, E> root) {
+      stack[0] = root;
+      final int pos = -root.inLeft;
+      poss[0] = pos;
+      sub = new FingerTreeIterator<>(root.get(pos), 0);
+    }
+
+    @Override
+    public boolean hasNext() {
+      return sub != null;
+    }
+
+    @Override
+    public E next() {
+      if(sub == null) throw new NoSuchElementException();
+      final E out = sub.next();
+      if(sub.hasNext()) return out;
+
+      // sub-iterator empty
+      sub = null;
+      final BufferNode<?, E> buffer = stack[top];
+      poss[top]++;
+
+      if(poss[top] < 0) {
+        sub = new FingerTreeIterator<>(buffer.get(poss[top]), 0);
+        return out;
+      }
+
+      if(poss[top] == 0) {
+        final Object mid = buffer.middle;
+        if(mid != null) {
+          if(mid instanceof FingerTree) {
+            sub = ((FingerTree<?, E>) mid).iterator();
+          } else {
+            final BufferNode<?, E> buff = (BufferNode<?, E>) mid;
+            if(++top == stack.length) {
+              stack = Arrays.copyOf(stack, 2 * top);
+              poss = Arrays.copyOf(poss, 2 * top);
+            }
+            stack[top] = buff;
+            poss[top] = -buff.inLeft;
+            sub = new FingerTreeIterator<>(buff.get(poss[top]), 0);
+          }
+          return out;
         }
+        poss[top]++;
       }
+
+      if(poss[top] <= buffer.inRight) {
+        sub = new FingerTreeIterator<>(buffer.get(poss[top] - 1), 0);
+        return out;
+      }
+
+      stack[top] = null;
+      if(--top >= 0) {
+        sub = new FingerTreeIterator<>(stack[top].get(0), 0);
+        poss[top]++;
+      }
+
+      return out;
+    }
+
+    @Override
+    public void remove() {
+      throw new UnsupportedOperationException();
     }
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/fingertree/FingerTreeIterator.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/fingertree/FingerTreeIterator.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/fingertree/FingerTreeIterator.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/fingertree/FingerTreeIterator.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,386 @@
+package org.basex.query.util.fingertree;
+
+import java.util.*;
+
+/**
+ * List iterator over the elements of a finger tree.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Leo Woerteler
+ *
+ * @param <E> element type
+ */
+final class FingerTreeIterator<E> implements ListIterator<E> {
+  /** Size of the root. */
+  private final long n;
+  /** Current index. */
+  private long index;
+
+  /** Stack of deep trees. */
+  private DeepTree<?, E>[] trees;
+  /** Position of the current node in the digits. */
+  private int deepPos;
+  /** Stack pointer for the deep trees. */
+  private int tTop = -1;
+
+  /** Node stack. */
+  private InnerNode<?, E>[] nodes;
+  /** Position stack. */
+  private int[] poss;
+  /** Stack pointer. */
+  private int nTop = -1;
+
+  /** Current leaf node. */
+  private Node<E, E> leaf;
+  /** Position inside the current leaf. */
+  private int leafPos;
+
+  /**
+   * Constructor for iterating over a single node.
+   * @param root root node
+   * @param start starting position
+   */
+  @SuppressWarnings("unchecked")
+  FingerTreeIterator(final Node<?, E> root, final long start) {
+    this.n = root.size();
+    this.index = start;
+
+    if(root instanceof InnerNode) {
+      this.nodes = new InnerNode[8];
+      this.poss = new int[8];
+      this.nTop = 0;
+      this.nodes[0] = (InnerNode<?, E>) root;
+    } else {
+      this.leaf = (Node<E, E>) root;
+      this.leafPos = (int) start;
+    }
+
+    assert start >= 0 && start <= this.n;
+  }
+
+  /**
+   * Constructor for iterating over a deep fingertree.
+   * @param tree finger tree
+   * @param start start position
+   */
+  @SuppressWarnings("unchecked")
+  FingerTreeIterator(final DeepTree<?, E> tree, final long start) {
+    this.n = tree.size();
+    this.index = start;
+
+    this.trees = new DeepTree[8];
+    this.trees[0] = tree;
+    this.tTop = 0;
+
+    this.nodes = new InnerNode[8];
+    this.poss = new int[8];
+    this.nTop = -1;
+  }
+
+  /**
+   * Returns a list iterator for the given finger tree starting at the given position.
+   * @param <E> element type
+   * @param tree finger tree
+   * @param start starting position
+   * @return the iterator
+   */
+  static <E> ListIterator<E> get(final FingerTree<?, E> tree, final long start) {
+    if(tree.isEmpty()) return Collections.emptyListIterator();
+    if(tree instanceof SingletonTree) return new FingerTreeIterator<>(tree.head(), start);
+    return new FingerTreeIterator<>((DeepTree<?, E>) tree, start);
+  }
+
+  /**
+   * Initializes this iterator by descending to the correct leaf node.
+   */
+  @SuppressWarnings("unchecked")
+  private void init() {
+    Node<?, E> node;
+    long pos = Math.min(index, n - 1);
+
+    if(tTop >= 0) {
+      for(;;) {
+        final DeepTree<?, E> curr = trees[tTop];
+        if(pos < curr.leftSize) {
+          // left digit
+          final Node<?, E>[] left = curr.left;
+          int i = 0;
+          for(;; i++) {
+            node = left[i];
+            final long sz = node.size();
+            if(pos < sz) break;
+            pos -= sz;
+          }
+          deepPos = i - left.length;
+          break;
+        }
+        pos -= curr.leftSize;
+
+        final FingerTree<?, E> mid = curr.middle;
+        final long midSize = mid.size();
+        if(pos >= midSize) {
+          // right digit
+          pos -= midSize;
+          final Node<?, E>[] right = curr.right;
+          int i = 0;
+          for(;; i++) {
+            node = right[i];
+            final long sz = node.size();
+            if(pos < sz) break;
+            pos -= sz;
+          }
+          deepPos = i + 1;
+          break;
+        }
+
+
+        if(mid instanceof SingletonTree) {
+          // single middle node
+          node = mid.head();
+          deepPos = 0;
+          break;
+        }
+
+        // go one level deeper
+        if(++tTop == trees.length) trees = Arrays.copyOf(trees, 2 * tTop);
+        trees[tTop] = (DeepTree<?, E>) mid;
+      }
+    } else {
+      deepPos = 0;
+      node = nodes[0];
+      nTop = -1;
+    }
+
+    Node<?, E> curr = node;
+    while(curr instanceof InnerNode) {
+      final InnerNode<?, E> inner = (InnerNode<?, E>) curr;
+
+      int idx = 0;
+      Node<?, E> sub = inner.getSub(0);
+      for(;;) {
+        final long sz = sub.size();
+        if(pos < sz) break;
+        pos -= sz;
+        sub = inner.getSub(++idx);
+      }
+
+      if(++nTop == nodes.length) {
+        nodes = Arrays.copyOf(nodes, 2 * nTop);
+        poss = Arrays.copyOf(poss, 2 * nTop);
+      }
+      nodes[nTop] = inner;
+      poss[nTop] = idx;
+      curr = sub;
+    }
+
+    leaf = (Node<E, E>) curr;
+    leafPos = (int) (index < n ? pos : pos + 1);
+  }
+
+  @Override
+  public int nextIndex() {
+    return (int) index;
+  }
+
+  @Override
+  public boolean hasNext() {
+    return index < n;
+  }
+
+  @Override
+  @SuppressWarnings("unchecked")
+  public E next() {
+    if(index >= n) throw new NoSuchElementException();
+    if(leaf == null) init();
+
+    index++;
+    if(leafPos < leaf.arity()) return leaf.getSub(leafPos++);
+
+    // leaf drained, backtrack
+    while(nTop >= 0 && poss[nTop] == nodes[nTop].arity() - 1) nTop--;
+
+    final Node<?, E> start;
+    if(nTop >= 0) {
+      // go to next sub-node
+      start = nodes[nTop].getSub(++poss[nTop]);
+    } else {
+      // node drained, move to the next one
+      final DeepTree<?, E> curr = trees[tTop];
+      if(deepPos < -1) {
+        // go to next node in digit
+        ++deepPos;
+        start = curr.left[curr.left.length + deepPos];
+      } else if(deepPos == -1) {
+        // left digit drained
+        final FingerTree<?, E> mid = curr.middle;
+        if(mid instanceof EmptyTree) {
+          // skip empty middle tree
+          deepPos = 1;
+          start = curr.right[0];
+        } else if(mid instanceof SingletonTree) {
+          // iterate through the one middle node
+          deepPos = 0;
+          start = ((SingletonTree<?, E>) mid).elem;
+        } else {
+          final DeepTree<?, E> deep = (DeepTree<?, E>) mid;
+          if(++tTop == trees.length) {
+            final DeepTree<?, E>[] newTrees = new DeepTree[2 * tTop];
+            System.arraycopy(trees, 0, newTrees, 0, tTop);
+            trees = newTrees;
+          }
+          trees[tTop] = deep;
+          deepPos = -deep.left.length;
+          start = deep.left[0];
+        }
+      } else if(deepPos == 0) {
+        // we are in a single middle node
+        deepPos = 1;
+        start = curr.right[0];
+      } else {
+        // we are in the right digit
+        final int p = deepPos - 1;
+        if(p < curr.right.length - 1) {
+          // go to next node in digit
+          deepPos++;
+          start = curr.right[p + 1];
+        } else {
+          // backtrack one level
+          trees[tTop] = null;
+          deepPos = 0;
+          tTop--;
+          start = trees[tTop].right[0];
+          deepPos = 1;
+        }
+      }
+    }
+
+    Node<?, E> sub = start;
+    while(sub instanceof InnerNode) {
+      if(++nTop == nodes.length) {
+        final InnerNode<?, E>[] newNodes = new InnerNode[2 * nTop];
+        System.arraycopy(nodes, 0, newNodes, 0, nTop);
+        nodes = newNodes;
+        poss = Arrays.copyOf(poss, 2 * nTop);
+      }
+      nodes[nTop] = (InnerNode<?, E>) sub;
+      poss[nTop] = 0;
+      sub = nodes[nTop].getSub(0);
+    }
+
+    leaf = (Node<E, E>) sub;
+    leafPos = 1;
+    return leaf.getSub(0);
+  }
+
+  @Override
+  public int previousIndex() {
+    return (int) (index - 1);
+  }
+
+  @Override
+  public boolean hasPrevious() {
+    return index > 0;
+  }
+
+  @Override
+  @SuppressWarnings("unchecked")
+  public E previous() {
+    if(index <= 0) throw new NoSuchElementException();
+    if(leaf == null) init();
+
+    --index;
+    if(leafPos > 0) return leaf.getSub(--leafPos);
+
+    // leaf drained, backtrack
+    while(nTop >= 0 && poss[nTop] == 0) nTop--;
+
+    final Node<?, E> start;
+    if(nTop >= 0) {
+      // go to previous sub-node
+      start = nodes[nTop].getSub(--poss[nTop]);
+    } else {
+      // node drained, move to the previous one
+      final DeepTree<?, E> curr = trees[tTop];
+      if(deepPos > 1) {
+        // go to next node in right digit
+        --deepPos;
+        start = curr.right[deepPos - 1];
+      } else if(deepPos == 1) {
+        // right digit drained
+        final FingerTree<?, E> mid = curr.middle;
+        if(mid instanceof EmptyTree) {
+          // skip empty middle tree
+          final int l = curr.left.length;
+          start = curr.left[l - 1];
+          deepPos = -1;
+        } else if(mid instanceof SingletonTree) {
+          // iterate through the one middle node
+          start = ((SingletonTree<?, E>) mid).elem;
+          deepPos = 0;
+        } else {
+          // go into the middle tree
+          final DeepTree<?, E> deep = (DeepTree<?, E>) mid;
+          if(++tTop == trees.length) {
+            final DeepTree<?, E>[] newTrees = new DeepTree[2 * tTop];
+            System.arraycopy(trees, 0, newTrees, 0, tTop);
+            trees = newTrees;
+          }
+          trees[tTop] = deep;
+          final int r = deep.right.length;
+          start = deep.right[r - 1];
+          deepPos = r;
+        }
+      } else if(deepPos == 0) {
+        start = curr.left[curr.left.length - 1];
+        deepPos = -1;
+      } else {
+        // we are in the left digit
+        final int l = curr.left.length, p = l + deepPos;
+        if(p > 0) {
+          // go to previous node in digit
+          --deepPos;
+          start = curr.left[p - 1];
+        } else {
+          // backtrack one level
+          trees[tTop] = null;
+          --tTop;
+          final Node<?, E>[] left = trees[tTop].left;
+          start = left[left.length - 1];
+          deepPos = -1;
+        }
+      }
+    }
+
+    Node<?, E> sub = start;
+    while(sub instanceof InnerNode) {
+      if(++nTop == nodes.length) {
+        final InnerNode<?, E>[] newNodes = new InnerNode[2 * nTop];
+        System.arraycopy(nodes, 0, newNodes, 0, nTop);
+        nodes = newNodes;
+        poss = Arrays.copyOf(poss, 2 * nTop);
+      }
+      nodes[nTop] = (InnerNode<?, E>) sub;
+      poss[nTop] = sub.arity() - 1;
+      sub = nodes[nTop].getSub(poss[nTop]);
+    }
+
+    leaf = (Node<E, E>) sub;
+    leafPos = sub.arity() - 1;
+    return leaf.getSub(leafPos);
+  }
+
+  @Override
+  public void set(final E e) {
+    throw new UnsupportedOperationException();
+  }
+
+  @Override
+  public void add(final E e) {
+    throw new UnsupportedOperationException();
+  }
+
+  @Override
+  public void remove() {
+    throw new UnsupportedOperationException();
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/fingertree/FingerTree.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/fingertree/FingerTree.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/fingertree/FingerTree.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/fingertree/FingerTree.java	2015-07-14 10:54:40.000000000 +0000
@@ -12,6 +12,11 @@
  * @param <E> element type
  */
 public abstract class FingerTree<N, E> implements Iterable<E> {
+  /** Maximum number of children in an inner node, tested values are 3 and 4. */
+  static final int MAX_ARITY = 4;
+  /** Maximum length of a digit. */
+  static final int MAX_DIGIT = MAX_ARITY + 1;
+
   /**
    * Returns the empty finger tree.
    * @param <E> element type
@@ -19,7 +24,7 @@
    */
   @SuppressWarnings("unchecked")
   public static final <E> FingerTree<E, E> empty() {
-    return (FingerTree<E, E>) Empty.INSTANCE;
+    return (FingerTree<E, E>) EmptyTree.INSTANCE;
   }
 
   /**
@@ -29,7 +34,7 @@
    * @return the singleton finger tree
    */
   public static final <E> FingerTree<E, E> singleton(final Node<E, E> leaf) {
-    return new Single<>(leaf);
+    return new SingletonTree<>(leaf);
   }
 
   /**
@@ -37,7 +42,7 @@
    * @return {@code true} if the node is empty, {@code false} otherwise
    */
   public final boolean isEmpty() {
-    return this == Empty.INSTANCE;
+    return this == EmptyTree.INSTANCE;
   }
 
   /**
@@ -52,13 +57,13 @@
     int level = 0;
     final Node<?, E> digit;
     while(true) {
-      if(curr instanceof Single) {
+      if(curr instanceof SingletonTree) {
         // we unpack the contained node one level
-        digit = ((Single<?, E>) curr).elem;
+        digit = ((SingletonTree<?, E>) curr).elem;
         break;
       }
 
-      final Deep<?, E> deep = (Deep<?, E>) curr;
+      final DeepTree<?, E> deep = (DeepTree<?, E>) curr;
       // check if index is in left digit
       if(pos < deep.leftSize) {
         Node<?, E> nd = null;
@@ -96,26 +101,12 @@
 
     Node<?, ?> nd = digit;
     for(; level > 0; level--) {
-      if(nd instanceof InnerNode2) {
-        final InnerNode2<?, ?> deep = (InnerNode2<?, ?>) nd;
-        if(pos < deep.l) {
-          nd = deep.child0;
-        } else {
-          nd = deep.child1;
-          pos -= deep.l;
-        }
-      } else {
-        final InnerNode3<?, ?> deep = (InnerNode3<?, ?>) nd;
-        if(pos < deep.l) {
-          nd = deep.child0;
-        } else if(pos < deep.m) {
-          nd = deep.child1;
-          pos -= deep.l;
-        } else {
-          nd = deep.child2;
-          pos -= deep.m;
-        }
-      }
+      final InnerNode<?, ?> deep = (InnerNode<?, ?>) nd;
+      final long[] bounds = deep.bounds;
+      int p = 0;
+      while(pos >= bounds[p]) p++;
+      if(p > 0) pos -= bounds[p - 1];
+      nd = deep.children[p];
     }
 
     @SuppressWarnings("unchecked")
@@ -172,10 +163,12 @@
   /**
    * Concatenates this finger tree with the given one.
    * @param mid nodes between the two trees
+   * @param sz sum of the sizes of all nodes in the middle array
    * @param other the other tree
    * @return concatenation of both trees
    */
-  public abstract FingerTree<N, E> concat(final Node<N, E>[] mid, final FingerTree<N, E> other);
+  public abstract FingerTree<N, E> concat(final Node<N, E>[] mid, final long sz,
+      final FingerTree<N, E> other);
 
   /**
    * Creates a reversed version of this tree.
@@ -231,50 +224,51 @@
    * @param size size of all nodes combined
    * @return constructed tree
    */
-  public static <N, E> FingerTree<N, E> buildTree(final Node<N, E>[] nodes, final int n,
+  static <N, E> FingerTree<N, E> buildTree(final Node<N, E>[] nodes, final int n,
       final long size) {
-    if(n == 1) return new Single<>(nodes[0]);
-    if(n < 7) {
+
+    if(n == 0) return EmptyTree.<N, E>getInstance();
+    if(n == 1) return new SingletonTree<>(nodes[0]);
+    if(n <= 2 * MAX_ARITY) {
       final int mid = n / 2;
       @SuppressWarnings("unchecked")
       final Node<N, E>[] left = new Node[mid], right = new Node[n - mid];
       System.arraycopy(nodes, 0, left, 0, mid);
       System.arraycopy(nodes, mid, right, 0, n - mid);
-      return Deep.get(left, right, size);
+      return DeepTree.get(left, right, size);
     }
 
-    final int k = n == 7 ? 2 : 3;
+    final int k = Math.min((n - MAX_ARITY) / 2, MAX_ARITY);
     @SuppressWarnings("unchecked")
     final Node<N, E>[] left = new Node[k], right = new Node[k];
     System.arraycopy(nodes, 0, left, 0, k);
     System.arraycopy(nodes, n - k, right, 0, k);
-    final long leftSize = Deep.size(left), rightSize = Deep.size(right);
+    final long leftSize = DeepTree.size(left), rightSize = DeepTree.size(right);
 
-    int remaining = n - 2 * k;
-    int i = k, j = 0;
     @SuppressWarnings("unchecked")
     final Node<Node<N, E>, E>[] outNodes = (Node<Node<N, E>, E>[]) nodes;
-    while(remaining > 4 || remaining == 3) {
-      outNodes[j++] = new InnerNode3<>(nodes[i++], nodes[i++], nodes[i++]);
-      remaining -= 3;
-    }
-
-    while(remaining > 0) {
-      outNodes[j++] = new InnerNode2<>(nodes[i++], nodes[i++]);
-      remaining -= 2;
+    final int remaining = n - 2 * k, ns = (remaining + MAX_ARITY - 1) / MAX_ARITY;
+    for(int i = 0, j = 0; i < ns; i++) {
+      final int rem = ns - i, sz = (remaining - j + rem - 1) / rem;
+      @SuppressWarnings("unchecked")
+      final Node<N, E>[] ch = new Node[sz];
+      System.arraycopy(nodes, j, ch, 0, sz);
+      outNodes[i] = new InnerNode<>(ch);
+      j += sz;
     }
 
-    final FingerTree<Node<N, E>, E> middle = buildTree(outNodes, j, size - leftSize - rightSize);
-    return new Deep<>(left, leftSize, middle, right, size);
+    final FingerTree<Node<N, E>, E> middle = buildTree(outNodes, ns, size - leftSize - rightSize);
+    return new DeepTree<>(left, leftSize, middle, right, size);
   }
 
   /**
    * Adds all nodes in the given array to the given side of this tree.
    * @param nodes the nodes
+   * @param sz sum of the sizes of all nodes in the array
    * @param left insertion direction, {@code true} adds to the left, {@code false} to the right
    * @return resulting tree
    */
-  abstract FingerTree<N, E> addAll(final Node<N, E>[] nodes, final boolean left);
+  abstract FingerTree<N, E> addAll(final Node<N, E>[] nodes, final long sz, final boolean left);
 
   @Override
   public final String toString() {
@@ -298,21 +292,39 @@
   public abstract long checkInvariants();
 
   /**
-   * Returns an array containing the number of elements stored at each level of the tree.
-   * @param depth current depth
-   * @return array of sizes
-   */
-  public abstract long[] sizes(int depth);
-
-  /**
    * Creates a {@link ListIterator} over the elements in this tree.
-   * @param reverse flag for starting at the back of the tree
+   * @param start starting position
+   *   (i.e. the position initially returned by {@link ListIterator#nextIndex()})
    * @return the list iterator
    */
-  public abstract ListIterator<E> listIterator(final boolean reverse);
+  public final ListIterator<E> listIterator(final long start) {
+    return FingerTreeIterator.get(this, start);
+  }
 
   @Override
   public final ListIterator<E> iterator() {
-    return listIterator(false);
+    return listIterator(0);
+  }
+
+  /**
+   * Writes a string representation of the given object to the given strun builder.
+   * @param obj object to write
+   * @param sb string builder
+   * @param indent indentation level
+   */
+  static void toString(final Object obj, final StringBuilder sb, final int indent) {
+    if(obj instanceof InnerNode) {
+      ((InnerNode<?, ?>) obj).toString(sb, indent);
+    } else if(obj instanceof PartialInnerNode) {
+      ((PartialInnerNode<?, ?>) obj).toString(sb, indent);
+    } else {
+      boolean fst = true;
+      for(final String line : obj.toString().split("\r\n?|\n")) {
+        for(int i = 0; i < indent; i++) sb.append(' ').append(' ');
+        sb.append(line);
+        if(fst) fst = false;
+        else sb.append('\n');
+      }
+    }
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/fingertree/InnerNode2.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/fingertree/InnerNode2.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/fingertree/InnerNode2.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/fingertree/InnerNode2.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,266 +0,0 @@
-package org.basex.query.util.fingertree;
-
-/**
- * An inner node with two sub-nodes.
- *
- * @author BaseX Team 2005-15, BSD License
- * @author Leo Woerteler
- *
- * @param <N> node type
- * @param <E> element type
- */
-final class InnerNode2<N, E> extends InnerNode<N, E> {
-  /** First sub-node. */
-  final Node<N, E> child0;
-  /** Second sub-node. */
-  final Node<N, E> child1;
-  /** End of the first sub-node. */
-  final long l;
-  /** End of the second sub-node. */
-  final long r;
-
-  /**
-   * Constructor for a binary node.
-   * @param a first sub-node
-   * @param b second sub-node
-   */
-  InnerNode2(final Node<N, E> a, final Node<N, E> b) {
-    child0 = a;
-    l = a.size();
-    child1 = b;
-    r = l + b.size();
-  }
-
-  @Override
-  protected long size() {
-    return r;
-  }
-
-  @Override
-  protected InnerNode<N, E> reverse() {
-    return new InnerNode2<>(child1.reverse(), child0.reverse());
-  }
-
-  @Override
-  protected boolean insert(final Node<Node<N, E>, E>[] siblings, final long pos, final E val) {
-    final InnerNode<N, E> left = (InnerNode<N, E>) siblings[0],
-        right = (InnerNode<N, E>) siblings[2];
-    @SuppressWarnings("unchecked")
-    final Node<N, E>[] sub = (Node<N, E>[]) siblings;
-    final Node<Node<N, E>, E> inserted;
-    if(pos < l || pos == l && l <= r - l) {
-      // insert into left sub-tree
-      sub[0] = null;
-      sub[2] = child1;
-      child0.insert(sub, pos, val);
-      final Node<N, E> a = sub[1], b = sub[2], c = sub[3];
-      inserted = c == null ? new InnerNode2<>(a, b) : new InnerNode3<>(a, b, c);
-    } else {
-      // insert into right sub-tree
-      sub[0] = child0;
-      sub[2] = null;
-      child1.insert(sub, pos - l, val);
-      final Node<N, E> a = sub[0], b = sub[1], c = sub[2];
-      inserted = c == null ? new InnerNode2<>(a, b) : new InnerNode3<>(a, b, c);
-    }
-
-    // restore the array
-    siblings[0] = left;
-    siblings[1] = inserted;
-    siblings[2] = right;
-    siblings[3] = null;
-    return false;
-  }
-
-  @Override
-  protected Node<Node<N, E>, E>[] remove(final Node<Node<N, E>, E> left,
-      final Node<Node<N, E>, E> right, final long pos) {
-    final Node<N, E>[] res;
-    final Node<N, E> split0, split1;
-    if(pos < l) {
-      res = child0.remove(null, child1, pos);
-      if(res[1] != null) {
-        split0 = res[1];
-        split1 = res[2];
-      } else {
-        split0 = res[2];
-        split1 = null;
-      }
-    } else {
-      res = child1.remove(child0, null, pos - l);
-      split0 = res[0];
-      split1 = res[1];
-    }
-
-    @SuppressWarnings("unchecked")
-    final Node<Node<N, E>, E>[] out = (Node<Node<N, E>, E>[]) res;
-
-    if(split1 != null) {
-      // nodes were not merged
-      out[0] = left;
-      out[1] = new InnerNode2<>(split0, split1);
-      out[2] = right;
-      return out;
-    }
-
-    if(left != null && left instanceof InnerNode3) {
-      // steal from the left
-      final InnerNode3<N, E> steal = (InnerNode3<N, E>) left;
-      out[0] = new InnerNode2<>(steal.child0, steal.child1);
-      out[1] = new InnerNode2<>(steal.child2, split0);
-      out[2] = right;
-      return out;
-    }
-
-    if(right != null && right instanceof InnerNode3) {
-      // steal from the right
-      final InnerNode3<N, E> steal = (InnerNode3<N, E>) right;
-      out[0] = left;
-      out[1] = new InnerNode2<>(split0, steal.child0);
-      out[2] = new InnerNode2<>(steal.child1, steal.child2);
-      return out;
-    }
-
-    if(left != null && (right == null || left.size() < right.size())) {
-      // merge with left neighbor
-      final InnerNode2<N, E> merge = (InnerNode2<N, E>) left;
-      out[0] = new InnerNode3<>(merge.child0, merge.child1, split0);
-      out[1] = null;
-      out[2] = right;
-    } else {
-      // merge with right neighbor
-      final InnerNode2<N, E> merge = (InnerNode2<N, E>) right;
-      out[0] = left;
-      out[1] = null;
-      out[2] = new InnerNode3<>(split0, merge.child0, merge.child1);
-    }
-
-    return out;
-  }
-
-  @Override
-  protected NodeLike<Node<N, E>, E> remove(final long pos) {
-    if(pos < l) {
-      final Node<N, E>[] res = child0.remove(null, child1, pos);
-      if(res[1] == null) return new PartialInnerNode<>(res[2]);
-      return new InnerNode2<>(res[1], res[2]);
-    }
-
-    final Node<N, E>[] res = child1.remove(child0, null, pos - l);
-    if(res[1] == null) return new PartialInnerNode<>(res[0]);
-    return new InnerNode2<>(res[0], res[1]);
-  }
-
-  @Override
-  protected NodeLike<Node<N, E>, E> slice(final long start, final long len) {
-    if(start >= l) {
-      // everything is in right sub-node
-      return new PartialInnerNode<>(len == r - l ? child1 : child1.slice(start - l, len));
-    }
-
-    if(start + len <= l) {
-      // everything is in left sub-node
-      return new PartialInnerNode<>(len == l ? child0 : child0.slice(start, len));
-    }
-
-    // both nodes are involved
-    final long inL = l - start, inR = len - inL;
-    final NodeLike<N, E> left = inL == l ? child0 : child0.slice(start, inL);
-    final NodeLike<N, E> right = inR == r - l ? child1 : child1.slice(0, inR);
-    if(left instanceof Node && right instanceof Node)
-      return new InnerNode2<>((Node<N, E>) left, (Node<N, E>) right);
-
-    final NodeLike<N, E>[] res = left.concat(right);
-    return res[1] == null ? new PartialInnerNode<>(res[0]) :
-      new InnerNode2<>((Node<N, E>) res[0], (Node<N, E>) res[1]);
-  }
-
-  @Override
-  protected NodeLike<Node<N, E>, E>[] concat(final NodeLike<Node<N, E>, E> other) {
-    if(other instanceof Node) {
-      @SuppressWarnings("unchecked")
-      final NodeLike<Node<N, E>, E>[] out = new NodeLike[] { this, other };
-      return out;
-    }
-
-    final NodeLike<N, E> sub = ((PartialInnerNode<N, E>) other).sub;
-    final NodeLike<N, E>[] merged = child1.concat(sub);
-    final Node<N, E> a = (Node<N, E>) merged[0], b = (Node<N, E>) merged[1];
-    @SuppressWarnings("unchecked")
-    final NodeLike<Node<N, E>, E>[] out = (NodeLike<Node<N, E>, E>[]) merged;
-    if(b == null) {
-      out[0] = new InnerNode2<>(child0, a);
-    } else {
-      out[0] = new InnerNode3<>(child0, a, b);
-      out[1] = null;
-    }
-    return out;
-  }
-
-  @Override
-  protected int append(final NodeLike<Node<N, E>, E>[] nodes, final int pos) {
-    if(pos == 0) {
-      nodes[0] = this;
-      return 1;
-    }
-
-    final NodeLike<Node<N, E>, E> left = nodes[pos - 1];
-    if(left instanceof Node) {
-      nodes[pos] = this;
-      return pos + 1;
-    }
-
-    final NodeLike<Node<N, E>, E>[] joined = left.concat(this);
-    nodes[pos - 1] = joined[0];
-    if(joined[1] == null) return pos;
-    nodes[pos] = joined[1];
-    return pos + 1;
-  }
-
-  @Override
-  protected void toString(final StringBuilder sb, final int indent) {
-    for(int i = 0; i < indent; i++) sb.append("  ");
-    sb.append("Node(").append(size()).append(")[\n");
-    child0.toString(sb, indent + 1);
-    sb.append("\n");
-    child1.toString(sb, indent + 1);
-    sb.append("\n");
-    for(int i = 0; i < indent; i++) sb.append("  ");
-    sb.append("]");
-  }
-
-  @Override
-  protected long checkInvariants() {
-    final long lCheck = child0.checkInvariants();
-    if(lCheck != l) throw new AssertionError("Wrong l: " + lCheck + " vs. " + l);
-    final long rCheck = lCheck + child1.checkInvariants();
-    if(rCheck != r) throw new AssertionError("Wrong r: " + rCheck + " vs. " + r);
-    return rCheck;
-  }
-
-  @Override
-  protected int arity() {
-    return 2;
-  }
-
-  @Override
-  protected Node<N, E> getSub(final int pos) {
-    return pos == 0 ? child0 : child1;
-  }
-
-  @Override
-  protected InnerNode<N, E> replaceFirst(final Node<N, E> newFirst) {
-    return newFirst == child0 ? this : new InnerNode2<>(newFirst, child1);
-  }
-
-  @Override
-  protected InnerNode<N, E> replaceLast(final Node<N, E> newLast) {
-    return newLast == child1 ? this : new InnerNode2<>(child0, newLast);
-  }
-
-  @Override
-  @SuppressWarnings("unchecked")
-  Node<N, E>[] copyChildren() {
-    return new Node[] { child0, child1 };
-  }
-}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/fingertree/InnerNode3.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/fingertree/InnerNode3.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/fingertree/InnerNode3.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/fingertree/InnerNode3.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,315 +0,0 @@
-package org.basex.query.util.fingertree;
-
-/**
- * An inner node with three sub-nodes.
- *
- * @author BaseX Team 2005-15, BSD License
- * @author Leo Woerteler
- *
- * @param <N> node type
- * @param <E> element type
- */
-final class InnerNode3<N, E> extends InnerNode<N, E> {
-  /** First sub-node. */
-  final Node<N, E> child0;
-  /** Second sub-node. */
-  final Node<N, E> child1;
-  /** Third sub-node. */
-  final Node<N, E> child2;
-  /** End of the first sub-node. */
-  final long l;
-  /** End of the second sub-node. */
-  final long m;
-  /** End of the third sub-node. */
-  final long r;
-
-  /**
-   * Constructor for a trinary node.
-   * @param a first sub-node
-   * @param b second sub-node
-   * @param c third sub-node
-   */
-  InnerNode3(final Node<N, E> a, final Node<N, E> b, final Node<N, E> c) {
-    this.child0 = a;
-    this.l = a.size();
-    this.child1 = b;
-    this.m = l + b.size();
-    this.child2 = c;
-    this.r = m + c.size();
-  }
-
-  @Override
-  protected long size() {
-    return r;
-  }
-
-  @Override
-  protected InnerNode<N, E> reverse() {
-    return new InnerNode3<>(child2.reverse(), child1.reverse(), child0.reverse());
-  }
-
-  @Override
-  protected boolean insert(final Node<Node<N, E>, E>[] siblings, final long pos, final E val) {
-    final InnerNode<N, E> left = (InnerNode<N, E>) siblings[0],
-        right = (InnerNode<N, E>) siblings[2];
-    @SuppressWarnings("unchecked")
-    final Node<N, E>[] sub = (Node<N, E>[]) siblings;
-    final Node<N, E> a, b, c, d;
-    if(pos <= l) {
-      // insert left
-      sub[0] = null;
-      sub[2] = child1;
-      child0.insert(sub, pos, val);
-      a = sub[1];
-      b = sub[2];
-      c = sub[3] == null ? child2 : sub[3];
-      d = sub[3] == null ? null : child2;
-    } else if(pos <= m) {
-      // insert in the middle
-      sub[0] = child0;
-      sub[2] = child2;
-      child1.insert(sub, pos - l, val);
-      a = sub[0];
-      b = sub[1];
-      c = sub[2];
-      d = sub[3];
-    } else {
-      // insert right
-      sub[0] = child1;
-      sub[2] = null;
-      child2.insert(sub, pos - m, val);
-      a = child0;
-      b = sub[0];
-      c = sub[1];
-      d = sub[2];
-    }
-
-    if(d == null) {
-      // no split
-      siblings[0] = left;
-      siblings[1] = new InnerNode3<>(a, b, c);
-      siblings[2] = right;
-      siblings[3] = null;
-      return false;
-    }
-
-    if(left != null && left instanceof InnerNode2) {
-      // merge with left sibling
-      final InnerNode2<N, E> deep2 = (InnerNode2<N, E>) left;
-      siblings[0] = new InnerNode3<>(deep2.child0, deep2.child1, a);
-      siblings[1] = new InnerNode3<>(b, c, d);
-      siblings[2] = right;
-      siblings[3] = null;
-      return false;
-    }
-
-    if(right != null && right instanceof InnerNode2) {
-      // merge with left sibling
-      final InnerNode2<N, E> deep2 = (InnerNode2<N, E>) right;
-      siblings[0] = left;
-      siblings[1] = new InnerNode3<>(a, b, c);
-      siblings[2] = new InnerNode3<>(d, deep2.child0, deep2.child1);
-      siblings[3] = null;
-      return false;
-    }
-
-    // split the node
-    siblings[0] = left;
-    siblings[1] = new InnerNode2<>(a, b);
-    siblings[2] = new InnerNode2<>(c, d);
-    siblings[3] = right;
-    return true;
-  }
-
-  @Override
-  protected InnerNode<N, E> remove(final long pos) {
-    if(pos < l) {
-      final Node<N, E>[] res = child0.remove(null, child1, pos);
-      if(res[1] == null) return new InnerNode2<>(res[2], child2);
-      return new InnerNode3<>(res[1], res[2], child2);
-    } else if(pos < m) {
-      final Node<N, E>[] res = child1.remove(child0, child2, pos - l);
-      if(res[1] == null) return new InnerNode2<>(res[0], res[2]);
-      return new InnerNode3<>(res[0], res[1], res[2]);
-    } else {
-      final Node<N, E>[] res = child2.remove(child1, null, pos - m);
-      if(res[1] == null) return new InnerNode2<>(child0, res[0]);
-      return new InnerNode3<>(child0, res[0], res[1]);
-    }
-  }
-
-  @Override
-  protected Node<Node<N, E>, E>[] remove(final Node<Node<N, E>, E> left,
-      final Node<Node<N, E>, E> right, final long pos) {
-    final Node<N, E>[] res;
-    final Node<Node<N, E>, E> node;
-    if(pos < l) {
-      res = child0.remove(null, child1, pos);
-      node = res[1] == null ? new InnerNode2<>(res[2], child2)
-                            : new InnerNode3<>(res[1], res[2], child2);
-    } else if(pos < m) {
-      res = child1.remove(child0, child2, pos - l);
-      node = res[1] == null ? new InnerNode2<>(res[0], res[2])
-                            : new InnerNode3<>(res[0], res[1], res[2]);
-    } else {
-      res = child2.remove(child1, null, pos - m);
-      node = res[1] == null ? new InnerNode2<>(child0, res[0])
-                            : new InnerNode3<>(child0, res[0], res[1]);
-    }
-
-    @SuppressWarnings("unchecked")
-    final Node<Node<N, E>, E>[] out = (Node<Node<N, E>, E>[]) res;
-    out[0] = left;
-    out[1] = node;
-    out[2] = right;
-    return out;
-  }
-
-  @Override
-  protected NodeLike<Node<N, E>, E> slice(final long start, final long len) {
-    final long end = start + len;
-    if(start < l) {
-      // left node involved
-      final long in0 = Math.min(l - start, len);
-      final NodeLike<N, E> slice0 = in0 == l ? child0 : child0.slice(start, in0);
-      if(end <= m) {
-        // no right node
-        if(end <= l) return new PartialInnerNode<>(slice0);
-        final NodeLike<N, E> slice1 = end == m ? child1 : child1.slice(0, end - l);
-        if(slice0 instanceof Node && slice1 instanceof Node)
-          return new InnerNode2<>((Node<N, E>) slice0, (Node<N, E>) slice1);
-
-        // partial nodes have to be merged
-        final NodeLike<N, E>[] merged = slice0.concat(slice1);
-        return merged[1] == null ? new PartialInnerNode<>(merged[0]) :
-          new InnerNode2<>((Node<N, E>) merged[0], (Node<N, E>) merged[1]);
-      }
-
-      // middle is contained completely
-      final long in2 = end - m;
-      final NodeLike<N, E> slice2 = in2 == r - m ? child2 : child2.slice(0, in2);
-      @SuppressWarnings("unchecked")
-      final NodeLike<N, E>[] ns = new NodeLike[3];
-      final int p0 = slice0.append(ns, 0), p1 = child1.append(ns, p0), p2 = slice2.append(ns, p1);
-      return p2 == 1 ? new PartialInnerNode<>(ns[0])
-           : p2 == 2 ? new InnerNode2<>((Node<N, E>) ns[0], (Node<N, E>) ns[1])
-                     : new InnerNode3<>((Node<N, E>) ns[0], (Node<N, E>) ns[1], (Node<N, E>) ns[2]);
-    }
-
-    if(start < m) {
-      // middle node included
-      final long in1 = Math.min(m - start, len);
-      final NodeLike<N, E> slice1 = in1 == m - l ? child1 : child1.slice(start - l, in1);
-      if(end <= m) return new PartialInnerNode<>(slice1);
-
-      // middle and last
-      final long in2 = end - m;
-      final NodeLike<N, E> slice2 = in2 == r - m ? child2 : child2.slice(0, in2);
-      if(slice1 instanceof Node && slice2 instanceof Node)
-        return new InnerNode2<>((Node<N, E>) slice1, (Node<N, E>) slice2);
-
-      // partial nodes have to be merged
-      final NodeLike<N, E>[] merged = slice1.concat(slice2);
-      return merged[1] == null ? new PartialInnerNode<>(merged[0]) :
-        new InnerNode2<>((Node<N, E>) merged[0], (Node<N, E>) merged[1]);
-    }
-
-    // only last node
-    final NodeLike<N, E> slice2 = r - m == len ? child2 : child2.slice(start - m, len);
-    return new PartialInnerNode<>(slice2);
-  }
-
-  @Override
-  protected NodeLike<Node<N, E>, E>[] concat(final NodeLike<Node<N, E>, E> other) {
-    if(other instanceof Node) {
-      @SuppressWarnings("unchecked")
-      final NodeLike<Node<N, E>, E>[] out = new NodeLike[] { this, other };
-      return out;
-    }
-
-    final NodeLike<N, E> sub = ((PartialInnerNode<N, E>) other).sub;
-    final NodeLike<N, E>[] merged = child2.concat(sub);
-    final Node<N, E> a = (Node<N, E>) merged[0], b = (Node<N, E>) merged[1];
-    @SuppressWarnings("unchecked")
-    final NodeLike<Node<N, E>, E>[] out = (NodeLike<Node<N, E>, E>[]) merged;
-    if(b == null) {
-      out[0] = new InnerNode3<>(child0, child1, a);
-    } else {
-      out[0] = new InnerNode2<>(child0, child1);
-      out[1] = new InnerNode2<>(a, b);
-    }
-
-    return out;
-  }
-
-  @Override
-  protected int append(final NodeLike<Node<N, E>, E>[] nodes, final int pos) {
-    if(pos == 0) {
-      nodes[0] = this;
-      return 1;
-    }
-
-    final NodeLike<Node<N, E>, E> left = nodes[pos - 1];
-    if(left instanceof Node) {
-      nodes[pos] = this;
-      return pos + 1;
-    }
-
-    final NodeLike<Node<N, E>, E>[] joined = left.concat(this);
-    nodes[pos - 1] = joined[0];
-    if(joined[1] == null) return pos;
-    nodes[pos] = joined[1];
-    return pos + 1;
-  }
-
-  @Override
-  protected void toString(final StringBuilder sb, final int indent) {
-    for(int i = 0; i < indent; i++) sb.append("  ");
-    sb.append("Node(").append(size()).append(")[\n");
-    child0.toString(sb, indent + 1);
-    sb.append("\n");
-    child1.toString(sb, indent + 1);
-    sb.append("\n");
-    child2.toString(sb, indent + 1);
-    sb.append("\n");
-    for(int i = 0; i < indent; i++) sb.append("  ");
-    sb.append("]");
-  }
-
-  @Override
-  protected long checkInvariants() {
-    final long lCheck = child0.checkInvariants();
-    if(lCheck != l) throw new AssertionError("Wrong l: " + lCheck + " vs. " + l);
-    final long mCheck = l + child1.checkInvariants();
-    if(mCheck != m) throw new AssertionError("Wrong m: " + mCheck + " vs. " + m);
-    final long rCheck = m + child2.checkInvariants();
-    if(rCheck != r) throw new AssertionError("Wrong r: " + rCheck + " vs. " + r);
-    return r;
-  }
-
-  @Override
-  protected int arity() {
-    return 3;
-  }
-
-  @Override
-  protected Node<N, E> getSub(final int pos) {
-    return pos == 0 ? child0 : pos == 1 ? child1 : child2;
-  }
-
-  @Override
-  protected InnerNode<N, E> replaceFirst(final Node<N, E> newFirst) {
-    return newFirst == child0 ? this : new InnerNode3<>(newFirst, child1, child2);
-  }
-
-  @Override
-  protected InnerNode<N, E> replaceLast(final Node<N, E> newLast) {
-    return newLast == child2 ? this : new InnerNode3<>(child0, child1, newLast);
-  }
-
-  @Override
-  @SuppressWarnings("unchecked")
-  Node<N, E>[] copyChildren() {
-    return new Node[] { child0, child1, child2 };
-  }
-}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/fingertree/InnerNode.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/fingertree/InnerNode.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/fingertree/InnerNode.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/fingertree/InnerNode.java	2015-07-14 10:54:40.000000000 +0000
@@ -9,10 +9,435 @@
  * @param <N> node type
  * @param <E> element type
  */
-abstract class InnerNode<N, E> extends Node<Node<N, E>, E> {
+final class InnerNode<N, E> implements Node<Node<N, E>, E> {
+  /** Child nodes. */
+  final Node<N, E>[] children;
+  /** Right bound for the elements' index in each sub-node. */
+  final long[] bounds;
+
   /**
-   * Returns a copy of this node's sub-nodes.
-   * @return an array containing this node's children
+   * Constructor.
+   * @param children children array
    */
-  abstract Node<N, E>[] copyChildren();
+  InnerNode(final Node<N, E>[] children) {
+    final int n = children.length;
+    this.children = children;
+    this.bounds = new long[n];
+    long off = 0;
+    for(int i = 0; i < n; i++) {
+      off += children[i].size();
+      bounds[i] = off;
+    }
+    assert 2 <= n && n <= FingerTree.MAX_ARITY;
+  }
+
+  @Override
+  public long size() {
+    return bounds[bounds.length - 1];
+  }
+
+  @Override
+  public int arity() {
+    return bounds.length;
+  }
+
+  @Override
+  public Node<N, E> getSub(final int pos) {
+    return children[pos];
+  }
+
+  @Override
+  public Node<Node<N, E>, E> reverse() {
+    final int n = children.length;
+    @SuppressWarnings("unchecked")
+    final Node<N, E>[] newChildren = new Node[n];
+    for(int i = 0; i < n; i++) newChildren[i] = children[n - 1 - i].reverse();
+    return new InnerNode<>(newChildren);
+  }
+
+  @Override
+  public boolean insert(final Node<Node<N, E>, E>[] siblings, final long index, final E val) {
+    final Node<Node<N, E>, E> left = siblings[0], right = siblings[2];
+
+    int i = 0;
+    final int n = bounds.length;
+    while(index > bounds[i]) i++;
+    final long off = i == 0 ? index : index - bounds[i - 1];
+
+    @SuppressWarnings("unchecked")
+    final Node<N, E>[] subs = (Node<N, E>[]) siblings;
+    subs[0] = i ==     0 ? null : children[i - 1];
+    subs[2] = i == n - 1 ? null : children[i + 1];
+
+    final int l = Math.max(0, i - 1), r = Math.min(i + 1, n - 1);
+    if(!children[i].insert(subs, off, val)) {
+      // no split
+      final Node<N, E>[] out = children.clone();
+      System.arraycopy(subs, i == 0 ? 1 : 0, out, l, r - l + 1);
+      siblings[0] = left;
+      siblings[1] = new InnerNode<>(out);
+      siblings[2] = right;
+      return false;
+    }
+
+    @SuppressWarnings("unchecked")
+    final Node<N, E>[] temp = new Node[n + 1];
+    if(i == 0) {
+      System.arraycopy(subs, 1, temp, 0, 3);
+      System.arraycopy(children, 2, temp, 3, n - 2);
+    } else if(i < n - 1) {
+      System.arraycopy(children, 0, temp, 0, l);
+      System.arraycopy(subs, 0, temp, l, 4);
+      System.arraycopy(children, r + 1, temp, l + 4, n - l - 3);
+    } else {
+      System.arraycopy(children, 0, temp, 0, n - 2);
+      System.arraycopy(subs, 0, temp, n - 2, 3);
+    }
+
+    if(n < FingerTree.MAX_ARITY) {
+      // still small enough
+      siblings[0] = left;
+      siblings[1] = new InnerNode<>(temp);
+      siblings[2] = right;
+      return false;
+    }
+
+    if(left != null) {
+      final int la = left.arity(), move = (FingerTree.MAX_ARITY - la + 1) / 2;
+      if(move > 0) {
+        // left node has capacity
+        final Node<N, E>[] ch = ((InnerNode<N, E>) left).children;
+        @SuppressWarnings("unchecked")
+        final Node<N, E>[] ls = new Node[la + move], rs = new Node[n + 1 - move];
+        System.arraycopy(ch, 0, ls, 0, la);
+        System.arraycopy(temp, 0, ls, la, move);
+        System.arraycopy(temp, move, rs, 0, rs.length);
+        siblings[0] = new InnerNode<>(ls);
+        siblings[1] = new InnerNode<>(rs);
+        siblings[2] = right;
+        return false;
+      }
+    }
+
+    if(right != null) {
+      final int ra = right.arity(), move = (FingerTree.MAX_ARITY - ra + 1) / 2;
+      if(move > 0) {
+        // right node has capacity
+        final Node<N, E>[] ch = ((InnerNode<N, E>) right).children;
+        @SuppressWarnings("unchecked")
+        final Node<N, E>[] ls = new Node[n + 1 - move], rs = new Node[ra + move];
+        System.arraycopy(temp, 0, ls, 0, ls.length);
+        System.arraycopy(temp, ls.length, rs, 0, move);
+        System.arraycopy(ch, 0, rs, move, ra);
+        siblings[0] = left;
+        siblings[1] = new InnerNode<>(ls);
+        siblings[2] = new InnerNode<>(rs);
+        return false;
+      }
+    }
+
+    if(left != null) {
+      // merge with left neighbor
+      final Node<N, E>[] ch = ((InnerNode<N, E>) left).children;
+      final int la = ch.length, k = la + n + 1, ml = k / 3, ll = k - 2 * ml, inL = la - ll;
+      @SuppressWarnings("unchecked")
+      final Node<N, E>[] ls = new Node[ll], mid1 = new Node[ml], mid2 = new Node[ml];
+      System.arraycopy(ch, 0, ls, 0, ll);
+      System.arraycopy(ch, ll, mid1, 0, inL);
+      System.arraycopy(temp, 0, mid1, inL, ml - inL);
+      System.arraycopy(temp, ml - inL, mid2, 0, ml);
+      siblings[0] = inL == 0 ? left : new InnerNode<>(ls);
+      siblings[1] = new InnerNode<>(mid1);
+      siblings[2] = new InnerNode<>(mid2);
+      siblings[3] = right;
+      return true;
+    }
+
+    if(right != null) {
+      // merge with right neighbor
+      final Node<N, E>[] ch = ((InnerNode<N, E>) right).children;
+      final int ra = ch.length, k = n + 1 + ra, ml = k / 3, rl = k - 2 * ml, inR = ra - rl;
+      @SuppressWarnings("unchecked")
+      final Node<N, E>[] mid1 = new Node[ml], mid2 = new Node[ml], rs = new Node[rl];
+      System.arraycopy(temp, 0, mid1, 0, ml);
+      System.arraycopy(temp, ml, mid2, 0, ml - inR);
+      System.arraycopy(ch, 0, mid2, ml - inR, inR);
+      System.arraycopy(ch, inR, rs, 0, rl);
+      siblings[0] = left;
+      siblings[1] = new InnerNode<>(mid1);
+      siblings[2] = new InnerNode<>(mid2);
+      siblings[3] = inR == 0 ? right : new InnerNode<>(rs);
+      return true;
+    }
+
+    // split the node
+    final int ll = (n + 1) / 2, rl = n + 1 - ll;
+    @SuppressWarnings("unchecked")
+    final Node<N, E>[] ls = new Node[ll], rs = new Node[rl];
+    System.arraycopy(temp, 0, ls, 0, ll);
+    System.arraycopy(temp, ll, rs, 0, rl);
+    siblings[0] = null;
+    siblings[1] = new InnerNode<>(ls);
+    siblings[2] = new InnerNode<>(rs);
+    siblings[3] = null;
+    return true;
+  }
+
+  @Override
+  public NodeLike<Node<N, E>, E>[] remove(final Node<Node<N, E>, E> left,
+      final Node<Node<N, E>, E> right, final long pos) {
+    int i = 0;
+    final int n = bounds.length;
+    while(pos >= bounds[i]) i++;
+    final long off = i == 0 ? pos : pos - bounds[i - 1];
+
+    final NodeLike<N, E>[] res = children[i].remove(
+        i ==     0 ? null : children[i - 1],
+        i == n - 1 ? null : children[i + 1], off);
+
+    @SuppressWarnings("unchecked")
+    final NodeLike<Node<N, E>, E>[] out = (NodeLike<Node<N, E>, E>[]) res;
+    final Node<N, E> l = (Node<N, E>) res[0], m = (Node<N, E>) res[1], r = (Node<N, E>) res[2];
+
+    if(m != null) {
+      // no underflow
+      final Node<N, E>[] ch = children.clone();
+      if(i > 0) ch[i - 1] = l;
+      ch[i] = m;
+      if(i < n - 1) ch[i + 1] = r;
+      out[0] = left;
+      out[1] = new InnerNode<>(ch);
+      out[2] = right;
+      return out;
+    }
+
+    if(n > 2) {
+      // still big enough
+      @SuppressWarnings("unchecked")
+      final Node<N, E>[] ch = new Node[n - 1];
+      if(i > 0) {
+        System.arraycopy(children, 0, ch, 0, i - 1);
+        ch[i - 1] = l;
+      }
+      if(i < n - 1) {
+        ch[i] = r;
+        System.arraycopy(children, i + 2, ch, i + 1, n - i - 2);
+      }
+      out[0] = left;
+      out[1] = new InnerNode<>(ch);
+      out[2] = right;
+      return out;
+    }
+
+    // only one sub-node left
+    final Node<N, E> single = i == 0 ? r : l;
+
+    if(left != null && left.arity() > 2) {
+      // refill from left sibling
+      final Node<N, E>[] ch = ((InnerNode<N, E>) left).children;
+      final int a = ch.length, move = (a - 1) / 2;
+      @SuppressWarnings("unchecked")
+      final Node<N, E>[] ls = new Node[a - move], ms = new Node[move + 1];
+      System.arraycopy(ch, 0, ls, 0, a - move);
+      System.arraycopy(ch, a - move, ms, 0, move);
+      ms[move] = single;
+      out[0] = new InnerNode<>(ls);
+      out[1] = new InnerNode<>(ms);
+      out[2] = right;
+      return out;
+    }
+
+    if(right != null && right.arity() > 2) {
+      // refill from right sibling
+      final Node<N, E>[] ch = ((InnerNode<N, E>) right).children;
+      final int a = ch.length, move = (a - 1) / 2;
+      @SuppressWarnings("unchecked")
+      final Node<N, E>[] ms = new Node[move + 1], rs = new Node[a - move];
+      ms[0] = single;
+      System.arraycopy(ch, 0, ms, 1, move);
+      System.arraycopy(ch, move, rs, 0, rs.length);
+      out[0] = left;
+      out[1] = new InnerNode<>(ms);
+      out[2] = new InnerNode<>(rs);
+      return out;
+    }
+
+    if(left != null) {
+      // merge with left sibling
+      final Node<N, E>[] ch = ((InnerNode<N, E>) left).children;
+      final int a = ch.length;
+      @SuppressWarnings("unchecked")
+      final Node<N, E>[] ls = new Node[a + 1];
+      System.arraycopy(ch, 0, ls, 0, a);
+      ls[a] = single;
+      out[0] = new InnerNode<>(ls);
+      out[2] = right;
+      return out;
+    }
+
+    if(right != null) {
+      // merge with right sibling
+      final Node<N, E>[] ch = ((InnerNode<N, E>) right).children;
+      final int a = ch.length;
+      @SuppressWarnings("unchecked")
+      final Node<N, E>[] rs = new Node[a + 1];
+      rs[0] = single;
+      System.arraycopy(ch, 0, rs, 1, a);
+      out[0] = left;
+      out[2] = new InnerNode<>(rs);
+      return out;
+    }
+
+    // underflow
+    out[0] = null;
+    out[1] = new PartialInnerNode<>(single);
+    out[2] = null;
+    return out;
+  }
+
+  @Override
+  @SuppressWarnings("unchecked")
+  public NodeLike<Node<N, E>, E> slice(final long start, final long len) {
+    // find the range of affected sub-nodes
+    int p = 0;
+    while(start >= bounds[p]) p++;
+    final long off = p == 0 ? start : start - bounds[p - 1], end = start + len - 1;
+    final int l = p;
+    while(end >= bounds[p]) p++;
+    final int r = p;
+
+    // first node can be partial
+    final Node<N, E> first = children[l];
+    final long inFst = Math.min(bounds[l] - start, len);
+    final NodeLike<N, E> fst = inFst == first.size() ? first : first.slice(off, inFst);
+    if(l == r) return new PartialInnerNode<>(fst);
+
+    // more than one node affected
+    final NodeLike<N, E>[] buffer = new NodeLike[r - l + 1];
+    buffer[0] = fst;
+    int inBuffer = 1;
+    for(int i = l + 1; i < r; i++) inBuffer = children[i].append(buffer, inBuffer);
+    final Node<N, E> last = children[r];
+    final long inLst = start + len - bounds[r - 1];
+    final NodeLike<N, E> lst = inLst == last.size() ? last : last.slice(0, inLst);
+    inBuffer = lst.append(buffer, inBuffer);
+
+    if(inBuffer == 1) {
+      // merged into a single sub-node
+      return new PartialInnerNode<>(buffer[0]);
+    }
+
+    // enough children for a full node
+    final Node<N, E>[] subs = new Node[inBuffer];
+    System.arraycopy(buffer, 0, subs, 0, inBuffer);
+    return new InnerNode<>(subs);
+  }
+
+  @Override
+  public long checkInvariants() {
+    final int a = children.length;
+    if(a < 2 || a > FingerTree.MAX_ARITY) throw new AssertionError("Wrong arity: " + a);
+    long b = 0;
+    for(int i = 0; i < a; i++) {
+      final Node<N, E> ch = children[i];
+      b += ch.checkInvariants();
+      if(b != bounds[i]) throw new AssertionError("Wrong boundary: " + b);
+    }
+    return b;
+  }
+
+  @Override
+  public int append(final NodeLike<Node<N, E>, E>[] nodes, final int pos) {
+    if(pos == 0 || nodes[pos - 1] instanceof InnerNode) {
+      nodes[pos] = this;
+      return pos + 1;
+    }
+
+    final NodeLike<N, E> sub = ((PartialInnerNode<N, E>) nodes[pos - 1]).sub;
+    final int n = children.length;
+    final Node<N, E> a, b;
+    if(sub instanceof Node) {
+      a = (Node<N, E>) sub;
+      b = children[0];
+    } else {
+      @SuppressWarnings("unchecked")
+      final NodeLike<N, E>[] buffer = (NodeLike<N, E>[]) nodes;
+      buffer[pos - 1] = sub;
+      if(children[0].append(buffer, pos) == pos) {
+        nodes[pos - 1] = replaceFirst((Node<N, E>) buffer[pos - 1]);
+        return pos;
+      }
+      a = (Node<N, E>) buffer[pos - 1];
+      b = (Node<N, E>) buffer[pos];
+    }
+
+    if(n < FingerTree.MAX_ARITY) {
+      @SuppressWarnings("unchecked")
+      final Node<N, E>[] ch = new Node[n + 1];
+      System.arraycopy(children, 1, ch, 2, n - 1);
+      ch[0] = a;
+      ch[1] = b;
+      nodes[pos - 1] = new InnerNode<>(ch);
+      nodes[pos] = null;
+      return pos;
+    }
+
+    final int rl = (n + 1) / 2, ll = n + 1 - rl;
+    @SuppressWarnings("unchecked")
+    final Node<N, E>[] ls = new Node[ll], rs = new Node[rl];
+    System.arraycopy(children, 1, ls, 2, ll - 2);
+    ls[0] = a;
+    ls[1] = b;
+    System.arraycopy(children, ll - 1, rs, 0, rl);
+    nodes[pos - 1] = new InnerNode<>(ls);
+    nodes[pos] = new InnerNode<>(rs);
+    return pos + 1;
+  }
+
+
+
+  /**
+   * Recursive helper method for {@link #toString()}.
+   * @param sb string builder
+   * @param indent indentation depth
+   */
+  public void toString(final StringBuilder sb, final int indent) {
+    for(int i = 0; i < indent; i++) sb.append("  ");
+    sb.append("Node(").append(size()).append(")[\n");
+    for(final Node<N, E> sub : children) {
+      FingerTree.toString(sub, sb, indent + 1);
+      sb.append("\n");
+    }
+    for(int i = 0; i < indent; i++) sb.append("  ");
+    sb.append("]");
+  }
+
+  @Override
+  public String toString() {
+    final StringBuilder sb = new StringBuilder();
+    toString(sb, 0);
+    return sb.toString();
+  }
+
+  /**
+   * Returns a version of this node where the first sub-node is the given one.
+   * @param newFirst new first sub-node
+   * @return resulting node
+   */
+  Node<Node<N, E>, E> replaceFirst(final Node<N, E> newFirst) {
+    final Node<N, E>[] copy = children.clone();
+    copy[0] = newFirst;
+    return new InnerNode<>(copy);
+  }
+
+  /**
+   * Returns a version of this node where the last sub-node is the given one.
+   * @param newLast new last sub-node
+   * @return resulting node
+   */
+  Node<Node<N, E>, E> replaceLast(final Node<N, E> newLast) {
+    final Node<N, E>[] copy = children.clone();
+    copy[copy.length - 1] = newLast;
+    return new InnerNode<>(copy);
+  }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/fingertree/NodeIterator.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/fingertree/NodeIterator.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/fingertree/NodeIterator.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/fingertree/NodeIterator.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,138 +0,0 @@
-package org.basex.query.util.fingertree;
-
-import java.util.*;
-
-/**
- * An {@link ListIterator} over the elements in a node.
- *
- * @author BaseX Team 2005-15, BSD License
- * @author Leo Woerteler
- *
- * @param <E> element type
- */
-public final class NodeIterator<E> implements ListIterator<E> {
-  /** Node stack. */
-  private InnerNode<?, E>[] nodes;
-  /** Position stack. */
-  private int[] poss;
-  /** Stack pointer. */
-  private int top;
-  /** Current leaf node. */
-  private Node<E, E> leaf;
-  /** Position inside the current leaf. */
-  private int leafPos;
-
-  /** Current index. */
-  private long index;
-  /** Number of elements in the root node. */
-  private final long rootSize;
-
-  /**
-   * Constructor.
-   * @param start root node
-   * @param reverse flag for starting at the back of the tree
-   */
-  @SuppressWarnings("unchecked")
-  NodeIterator(final Node<?, E> start, final boolean reverse) {
-    nodes = new InnerNode[8];
-    poss = new int[8];
-    rootSize = start.size();
-    index = reverse ? rootSize : 0;
-    top = -1;
-    Node<?, E> curr = start;
-    while(curr instanceof InnerNode) {
-      final InnerNode<?, E> inner = (InnerNode<?, E>) curr;
-      final int idx = reverse ? inner.arity() - 1 : 0;
-      if(++top == nodes.length) {
-        final InnerNode<?, E>[] newNodes = new InnerNode[2 * top];
-        System.arraycopy(nodes, 0, newNodes, 0, top);
-        nodes = newNodes;
-        final int[] newPoss = new int[2 * top];
-        System.arraycopy(poss, 0, newPoss, 0, top);
-        poss = newPoss;
-      }
-      nodes[top] = inner;
-      poss[top] = idx;
-      curr = inner.getSub(idx);
-    }
-    leaf = (Node<E, E>) curr;
-    leafPos = reverse ? curr.arity() : 0;
-  }
-
-  @Override
-  public boolean hasNext() {
-    return index < rootSize;
-  }
-
-  @Override
-  public int nextIndex() {
-    return (int) index;
-  }
-
-  @Override
-  @SuppressWarnings("unchecked")
-  public E next() {
-    if(index >= rootSize) throw new NoSuchElementException();
-    index++;
-    if(leafPos >= leaf.arity()) {
-      while(poss[top] >= nodes[top].arity() - 1) top--;
-      poss[top]++;
-      Node<?, E> sub = nodes[top].getSub(poss[top]);
-      while(sub instanceof InnerNode) {
-        ++top;
-        nodes[top] = (InnerNode<?, E>) sub;
-        poss[top] = 0;
-        sub = nodes[top].getSub(0);
-      }
-      leaf = (Node<E, E>) sub;
-      leafPos = 0;
-    }
-    return leaf.getSub(leafPos++);
-  }
-
-  @Override
-  public boolean hasPrevious() {
-    return index > 0;
-  }
-
-  @Override
-  public int previousIndex() {
-    return (int) (index - 1);
-  }
-
-  @Override
-  @SuppressWarnings("unchecked")
-  public E previous() {
-    if(index <= 0) throw new NoSuchElementException();
-    index--;
-    if(leafPos <= 0) {
-      while(poss[top] <= 0) top--;
-      poss[top]--;
-      Node<?, E> sub = nodes[top].getSub(poss[top]);
-      while(sub instanceof InnerNode) {
-        ++top;
-        nodes[top] = (InnerNode<?, E>) sub;
-        poss[top] = sub.arity() - 1;
-        sub = nodes[top].getSub(poss[top]);
-      }
-      leaf = (Node<E, E>) sub;
-      leafPos = sub.arity();
-    }
-    return leaf.getSub(--leafPos);
-  }
-
-  @Override
-  public void set(final E e) {
-    throw new UnsupportedOperationException();
-  }
-
-  @Override
-  public void add(final E e) {
-    throw new UnsupportedOperationException();
-  }
-
-  @Override
-  public void remove() {
-    throw new UnsupportedOperationException();
-  }
-}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/fingertree/Node.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/fingertree/Node.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/fingertree/Node.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/fingertree/Node.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,7 +1,5 @@
 package org.basex.query.util.fingertree;
 
-import java.util.*;
-
 /**
  * A node inside a digit.
  *
@@ -11,31 +9,31 @@
  * @param <N> node type
  * @param <E> element type
  */
-public abstract class Node<N, E> extends NodeLike<N, E> implements Iterable<E> {
+public interface Node<N, E> extends NodeLike<N, E> {
   /**
    * Number of elements in this node.
    * @return number of elements
    */
-  protected abstract long size();
+  long size();
 
   /**
    * Number of children of this node.
    * @return number of children
    */
-  protected abstract int arity();
+  int arity();
 
   /**
    * Returns the sub-node at the given position in this node.
    * @param pos index of the sub-node, must be between 0 and {@link #arity()} - 1
    * @return the sub-node
    */
-  protected abstract N getSub(final int pos);
+  N getSub(final int pos);
 
   /**
    * Creates a reversed version of this node.
    * @return a node with the reverse order of contained elements
    */
-  protected abstract Node<N, E> reverse();
+  Node<N, E> reverse();
 
   /**
    * Inserts the given element at the given position in this node.
@@ -57,25 +55,18 @@
    * @param val value to insert
    * @return {@code true} if the node was split, {@code false} otherwise
    */
-  protected abstract boolean insert(Node<N, E>[] siblings, final long pos, final E val);
+  boolean insert(Node<N, E>[] siblings, final long pos, final E val);
 
   /**
    * Removes the element at the given position in this node.
-   * @param pos position of the element to remove
-   * @return possibly partial resulting node
-   */
-  protected abstract NodeLike<N, E> remove(final long pos);
-
-  /**
-   * Removes the element at the given position in this node. Either the left or the right
-   * neighbor must be given for balancing. If this node is merged with one of its neighbors, the
-   * middle element of the result array is {@code null}.
+   * If this node is merged with one of its neighbors,
+   * the middle element of the result array is {@code null}.
    * @param l left neighbor, possibly {@code null}
    * @param r right neighbor, possibly {@code null}
    * @param pos position of the element to delete
    * @return three-element array with the new left neighbor, node and right neighbor
    */
-  protected abstract Node<N, E>[] remove(final Node<N, E> l, final Node<N, E> r, final long pos);
+  NodeLike<N, E>[] remove(final Node<N, E> l, final Node<N, E> r, final long pos);
 
   /**
    * Extracts a sub-tree containing the elements at positions {@code off .. off + len - 1}
@@ -85,40 +76,12 @@
    * @param len number of elements
    * @return the sub-tree, possibly under-full
    */
-  protected abstract NodeLike<N, E> slice(final long off, final long len);
-
-  /**
-   * Returns a version of this node where the first sub-node is the given one.
-   * @param newFirst new first sub-node
-   * @return resulting node
-   */
-  protected abstract Node<N, E> replaceFirst(N newFirst);
-
-  /**
-   * Returns a version of this node where the last sub-node is the given one.
-   * @param newLast new last sub-node
-   * @return resulting node
-   */
-  protected abstract Node<N, E> replaceLast(N newLast);
+  NodeLike<N, E> slice(final long off, final long len);
 
   /**
    * Checks that this node does not violate any invariants.
    * @return this node's size
    * @throws AssertionError if an invariant was violated
    */
-  protected abstract long checkInvariants();
-
-  @Override
-  public final NodeIterator<E> iterator() {
-    return new NodeIterator<>(this, false);
-  }
-
-  /**
-   * Creates a {@link ListIterator} over the elements in this node.
-   * @param reverse flag for starting at the back of this node
-   * @return the list iterator
-   */
-  public final NodeIterator<E> listIterator(final boolean reverse) {
-    return new NodeIterator<>(this, reverse);
-  }
+  long checkInvariants();
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/fingertree/NodeLike.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/fingertree/NodeLike.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/fingertree/NodeLike.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/fingertree/NodeLike.java	2015-07-14 10:54:40.000000000 +0000
@@ -9,38 +9,12 @@
  * @param <N> node type
  * @param <E> element type
  */
-public abstract class NodeLike<N, E> {
-  /** Default constructor for package visibility. */
-  NodeLike() {
-  }
-
-  /**
-   * Concatenates this possibly partial node with the given one.
-   * This method is allowed to re-use the result array from a recursive call for performance.
-   * @param other the other node-like object
-   * @return a two-element array containing the one or two resulting node-like objects
-   */
-  protected abstract NodeLike<N, E>[] concat(final NodeLike<N, E> other);
-
+public interface NodeLike<N, E> {
   /**
    * Appends this possibly partial node to the given buffer.
    * @param nodes the buffer
    * @param pos number of nodes in the buffer
    * @return new number of nodes
    */
-  protected abstract int append(final NodeLike<N, E>[] nodes, final int pos);
-
-  /**
-   * Recursive helper method for {@link #toString()}.
-   * @param sb string builder
-   * @param indent indentation depth
-   */
-  protected abstract void toString(final StringBuilder sb, final int indent);
-
-  @Override
-  public final String toString() {
-    final StringBuilder sb = new StringBuilder();
-    toString(sb, 0);
-    return sb.toString();
-  }
+  int append(final NodeLike<N, E>[] nodes, final int pos);
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/fingertree/PartialInnerNode.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/fingertree/PartialInnerNode.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/fingertree/PartialInnerNode.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/fingertree/PartialInnerNode.java	2015-07-14 10:54:40.000000000 +0000
@@ -9,7 +9,7 @@
  * @param <N> node type
  * @param <E> element type
  */
-final class PartialInnerNode<N, E> extends PartialNode<Node<N, E>, E> {
+final class PartialInnerNode<N, E> implements NodeLike<Node<N, E>, E> {
   /** The sub-node. */
   final NodeLike<N, E> sub;
 
@@ -22,76 +22,97 @@
   }
 
   @Override
-  protected NodeLike<Node<N, E>, E>[] concat(final NodeLike<Node<N, E>, E> other) {
-    if(other instanceof PartialInnerNode) {
-      final PartialInnerNode<N, E> single = (PartialInnerNode<N, E>) other;
-      final NodeLike<N, E>[] merged = sub.concat(single.sub);
-      final NodeLike<N, E> a = merged[0], b = merged[1];
-
-      @SuppressWarnings("unchecked")
-      final NodeLike<Node<N, E>, E>[] out = (NodeLike<Node<N, E>, E>[]) merged;
-      if(b == null) {
-        out[0] = new PartialInnerNode<>(a);
-      } else {
-        out[0] = new InnerNode2<>((Node<N, E>) a, (Node<N, E>) b);
-        out[1] = null;
-      }
-      return out;
+  public int append(final NodeLike<Node<N, E>, E>[] out, final int pos) {
+    if(pos == 0) {
+      out[0] = this;
+      return 1;
     }
 
-    final InnerNode<N, E> deep0 = (InnerNode<N, E>) other;
-    final NodeLike<N, E>[] merged = sub.concat(deep0.getSub(0));
-
-    // merging with a full node cannot result in under-full nodes
-    final Node<N, E> a = (Node<N, E>) merged[0], b = (Node<N, E>) merged[1];
     @SuppressWarnings("unchecked")
-    final NodeLike<Node<N, E>, E>[] out = (NodeLike<Node<N, E>, E>[]) merged;
-
-    if(other instanceof InnerNode2) {
-      final InnerNode2<N, E> deep = (InnerNode2<N, E>) other;
-      if(b == null) {
-        out[0] = new InnerNode2<>(a, deep.child1);
-      } else {
-        out[0] = new InnerNode3<>(a, b, deep.child1);
-        out[1] = null;
-      }
-    } else {
-      final InnerNode3<N, E> deep = (InnerNode3<N, E>) other;
-      if(b == null) {
-        out[0] = new InnerNode3<>(a, deep.child1, deep.child2);
+    final NodeLike<N, E>[] buffer = (NodeLike<N, E>[]) out;
+    final NodeLike<Node<N, E>, E> left = out[pos - 1];
+    if(left instanceof PartialInnerNode) {
+      buffer[pos - 1] = ((PartialInnerNode<N, E>) left).sub;
+      if(sub.append(buffer, pos) == pos) {
+        out[pos - 1] = new PartialInnerNode<>(buffer[pos - 1]);
       } else {
-        out[0] = new InnerNode2<>(a, b);
-        out[1] = new InnerNode2<>(deep.child1, deep.child2);
+        @SuppressWarnings("unchecked")
+        final Node<N, E>[] ch = new Node[2];
+        ch[0] = (Node<N, E>) buffer[pos - 1];
+        ch[1] = (Node<N, E>) buffer[pos];
+        out[pos - 1] = new InnerNode<>(ch);
+        out[pos] = null;
       }
+      return pos;
     }
-    return out;
-  }
 
-  @Override
-  protected int append(final NodeLike<Node<N, E>, E>[] nodes, final int pos) {
-    if(pos == 0) {
-      nodes[pos] = this;
-      return 1;
+    final Node<N, E>[] children = ((InnerNode<N, E>) left).children;
+    final int n = children.length;
+    final Node<N, E> a, b;
+    if(sub instanceof Node) {
+      a = children[n - 1];
+      b = (Node<N, E>) sub;
+    } else {
+      buffer[pos - 1] = children[n - 1];
+      if(sub.append(buffer, pos) == pos) {
+        final Node<N, E>[] ch = children.clone();
+        ch[n - 1] = (Node<N, E>) buffer[pos - 1];
+        out[pos - 1] = new InnerNode<>(ch);
+        return pos;
+      }
+      a = (Node<N, E>) buffer[pos - 1];
+      b = (Node<N, E>) buffer[pos];
     }
 
-    final NodeLike<Node<N, E>, E>[] joined = nodes[pos - 1].concat(this);
-    nodes[pos - 1] = joined[0];
-
-    if(joined[1] != null) {
-      nodes[pos] = joined[1];
-      return pos + 1;
+    if(n < FingerTree.MAX_ARITY) {
+      @SuppressWarnings("unchecked")
+      final Node<N, E>[] ch = new Node[n + 1];
+      System.arraycopy(children, 0, ch, 0, n - 1);
+      ch[n - 1] = a;
+      ch[n] = b;
+      out[pos - 1] = new InnerNode<>(ch);
+      out[pos] = null;
+      return pos;
     }
 
-    return pos;
+    final int ll = (n + 1) / 2, rl = n + 1 - ll;
+    @SuppressWarnings("unchecked")
+    final Node<N, E>[] ls = new Node[ll], rs = new Node[rl];
+    System.arraycopy(children, 0, ls, 0, ll);
+    System.arraycopy(children, ll, rs, 0, rl - 2);
+    rs[rl - 2] = a;
+    rs[rl - 1] = b;
+    out[pos - 1] = new InnerNode<>(ls);
+    out[pos] = new InnerNode<>(rs);
+    return pos + 1;
   }
 
   @Override
-  protected void toString(final StringBuilder sb, final int indent) {
-    for(int i = 0; i < indent; i++) sb.append("  ");
-    sb.append("OneSubnode[\n");
-    sub.toString(sb, indent + 1);
-    sb.append('\n');
-    for(int i = 0; i < indent; i++) sb.append("  ");
+  public String toString() {
+    final StringBuilder sb = new StringBuilder();
+    toString(sb, 0);
+    return sb.toString();
+  }
+
+  /**
+   * Recursive helper for {@link #toString()}.
+   * @param sb string builder
+   * @param indent indentation level
+   */
+  void toString(final StringBuilder sb, final int indent) {
+    for(int i = 0; i < indent; i++) sb.append(' ').append(' ');
+    sb.append(this.getClass().getSimpleName()).append('[').append('\n');
+    if(sub instanceof InnerNode) {
+      ((InnerNode<?, ?>) sub).toString(sb, indent + 1);
+    } else if(sub instanceof PartialInnerNode) {
+      ((PartialInnerNode<?, ?>) sub).toString(sb, indent + 1);
+    } else {
+      for(final String line : sub.toString().split("\r\n?|\n")) {
+        for(int i = 0; i <= indent; i++) sb.append(' ').append(' ');
+        sb.append(line).append('\n');
+      }
+    }
+    for(int i = 0; i < indent; i++) sb.append(' ').append(' ');
     sb.append(']');
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/fingertree/PartialNode.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/fingertree/PartialNode.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/fingertree/PartialNode.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/fingertree/PartialNode.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,14 +0,0 @@
-package org.basex.query.util.fingertree;
-
-/**
- * A partial node containing less than two children.
- *
- * @author BaseX Team 2005-15, BSD License
- * @author Leo Woerteler
- *
- * @param <N> node type
- * @param <E> element type
- */
-public abstract class PartialNode<N, E> extends NodeLike<N, E> {
-
-}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/fingertree/Single.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/fingertree/Single.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/fingertree/Single.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/fingertree/Single.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,156 +0,0 @@
-package org.basex.query.util.fingertree;
-
-import java.util.*;
-
-/**
- * A tree consisting of a single value.
- *
- * @author BaseX Team 2005-15, BSD License
- * @author Leo Woerteler
- *
- * @param <N> node type
- * @param <E> element type
- */
-final class Single<N, E> extends FingerTree<N, E> {
-  /** The element. */
-  final Node<N, E> elem;
-
-  /**
-   * Constructor.
-   * @param elem element
-   */
-  public Single(final Node<N, E> elem) {
-    this.elem = elem;
-  }
-
-  @Override
-  public Deep<N, E> cons(final Node<N, E> fst) {
-    final long leftSize = fst.size();
-    @SuppressWarnings("unchecked")
-    final Node<N, E>[] left = new Node[] { fst }, right = new Node[] { elem };
-    return Deep.get(left, leftSize, right, leftSize + elem.size());
-  }
-
-  @Override
-  public Deep<N, E> snoc(final Node<N, E> lst) {
-    final long leftSize = elem.size();
-    @SuppressWarnings("unchecked")
-    final Node<N, E>[] left = new Node[] { elem }, right = new Node[] { lst };
-    return Deep.get(left, leftSize, right, leftSize + lst.size());
-  }
-
-  @Override
-  public Node<N, E> head() {
-    return elem;
-  }
-
-  @Override
-  public Node<N, E> last() {
-    return elem;
-  }
-
-  @Override
-  public FingerTree<N, E> init() {
-    return Empty.getInstance();
-  }
-
-  @Override
-  public FingerTree<N, E> tail() {
-    return Empty.getInstance();
-  }
-
-  @Override
-  public long size() {
-    return elem.size();
-  }
-
-  @Override
-  public FingerTree<N, E> concat(final Node<N, E>[] mid, final FingerTree<N, E> other) {
-    return other.isEmpty() ? addAll(mid, false) : other.addAll(mid, true).cons(elem);
-  }
-
-  @Override
-  public FingerTree<N, E> reverse() {
-    return new Single<>(elem.reverse());
-  }
-
-  @Override
-  public FingerTree<N, E> insert(final long pos, final E val) {
-    @SuppressWarnings("unchecked")
-    final Node<N, E>[] siblings = new Node[4];
-    if(!elem.insert(siblings, pos, val)) {
-      // node was not split
-      return new Single<>(siblings[1]);
-    }
-
-    final Node<N, E> l = siblings[1], r = siblings[2];
-    @SuppressWarnings("unchecked")
-    final Node<N, E>[] left = new Node[] { l }, right = new Node[] { r };
-    return Deep.get(left, l.size(), right, elem.size() + 1);
-  }
-
-  @Override
-  public TreeSlice<N, E> remove(final long pos) {
-    final NodeLike<N, E> removed = elem.remove(pos);
-    return removed instanceof Node ? new TreeSlice<>(new Single<>((Node<N, E>) removed))
-                                   : new TreeSlice<>((PartialNode<N, E>) removed);
-  }
-
-  @Override
-  public TreeSlice<N, E> slice(final long pos, final long len) {
-    if(pos == 0 && len == elem.size()) return new TreeSlice<>(this);
-    final NodeLike<N, E> sub = elem.slice(pos, len);
-    if(sub instanceof Node) return new TreeSlice<>(new Single<>((Node<N, E>) sub));
-    return new TreeSlice<>((PartialNode<N, E>) sub);
-  }
-
-  @Override
-  public ListIterator<E> listIterator(final boolean reverse) {
-    return elem.listIterator(reverse);
-  }
-
-  @Override
-  FingerTree<N, E> addAll(final Node<N, E>[] nodes, final boolean left) {
-    if(nodes.length == 0) return this;
-    if(nodes.length <= 4) {
-      @SuppressWarnings("unchecked")
-      final Node<N, E>[] arr = new Node[] { elem };
-      return Deep.get(left ? nodes : arr, left ? arr : nodes);
-    }
-
-    final FingerTree<N, E> tree = buildTree(nodes, nodes.length, Deep.size(nodes));
-    return left ? tree.snoc(elem) : tree.cons(elem);
-  }
-
-  @Override
-  public FingerTree<N, E> replaceHead(final Node<N, E> head) {
-    return new Single<>(head);
-  }
-
-  @Override
-  public FingerTree<N, E> replaceLast(final Node<N, E> head) {
-    return new Single<>(head);
-  }
-
-  @Override
-  void toString(final StringBuilder sb, final int indent) {
-    for(int i = 0; i < indent; i++) sb.append("  ");
-    sb.append("Single[\n");
-    elem.toString(sb, indent + 1);
-    sb.append("\n");
-    for(int i = 0; i < indent; i++) sb.append("  ");
-    sb.append("]");
-  }
-
-  @Override
-  public long checkInvariants() {
-    return elem.checkInvariants();
-  }
-
-  @Override
-  public long[] sizes(final int depth) {
-    final long[] sizes = new long[depth + 1];
-    sizes[depth] = elem.size();
-    return sizes;
-  }
-}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/fingertree/SingletonTree.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/fingertree/SingletonTree.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/fingertree/SingletonTree.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/fingertree/SingletonTree.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,140 @@
+package org.basex.query.util.fingertree;
+
+/**
+ * A tree consisting of a single value.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Leo Woerteler
+ *
+ * @param <N> node type
+ * @param <E> element type
+ */
+final class SingletonTree<N, E> extends FingerTree<N, E> {
+  /** The element. */
+  final Node<N, E> elem;
+
+  /**
+   * Constructor.
+   * @param elem element
+   */
+  public SingletonTree(final Node<N, E> elem) {
+    this.elem = elem;
+  }
+
+  @Override
+  public DeepTree<N, E> cons(final Node<N, E> fst) {
+    final long leftSize = fst.size();
+    @SuppressWarnings("unchecked")
+    final Node<N, E>[] left = new Node[] { fst }, right = new Node[] { elem };
+    return DeepTree.get(left, leftSize, right, leftSize + elem.size());
+  }
+
+  @Override
+  public DeepTree<N, E> snoc(final Node<N, E> lst) {
+    final long leftSize = elem.size();
+    @SuppressWarnings("unchecked")
+    final Node<N, E>[] left = new Node[] { elem }, right = new Node[] { lst };
+    return DeepTree.get(left, leftSize, right, leftSize + lst.size());
+  }
+
+  @Override
+  public Node<N, E> head() {
+    return elem;
+  }
+
+  @Override
+  public Node<N, E> last() {
+    return elem;
+  }
+
+  @Override
+  public FingerTree<N, E> init() {
+    return EmptyTree.getInstance();
+  }
+
+  @Override
+  public FingerTree<N, E> tail() {
+    return EmptyTree.getInstance();
+  }
+
+  @Override
+  public long size() {
+    return elem.size();
+  }
+
+  @Override
+  public FingerTree<N, E> concat(final Node<N, E>[] mid, final long sz,
+      final FingerTree<N, E> other) {
+    return other.isEmpty() ? addAll(mid, sz, false) : other.addAll(mid, sz, true).cons(elem);
+  }
+
+  @Override
+  public FingerTree<N, E> reverse() {
+    return new SingletonTree<>(elem.reverse());
+  }
+
+  @Override
+  public FingerTree<N, E> insert(final long pos, final E val) {
+    @SuppressWarnings("unchecked")
+    final Node<N, E>[] siblings = new Node[4];
+    if(!elem.insert(siblings, pos, val)) {
+      // node was not split
+      return new SingletonTree<>(siblings[1]);
+    }
+
+    final Node<N, E> l = siblings[1], r = siblings[2];
+    @SuppressWarnings("unchecked")
+    final Node<N, E>[] left = new Node[] { l }, right = new Node[] { r };
+    return DeepTree.get(left, l.size(), right, elem.size() + 1);
+  }
+
+  @Override
+  public TreeSlice<N, E> remove(final long pos) {
+    final NodeLike<N, E>[] removed = elem.remove(null, null, pos);
+    return new TreeSlice<>(removed[1]);
+  }
+
+  @Override
+  public TreeSlice<N, E> slice(final long pos, final long len) {
+    if(pos == 0 && len == elem.size()) return new TreeSlice<>(this);
+    return new TreeSlice<>(elem.slice(pos, len));
+  }
+
+  @Override
+  FingerTree<N, E> addAll(final Node<N, E>[] nodes, final long sz, final boolean left) {
+    if(nodes.length == 0) return this;
+    if(nodes.length <= MAX_DIGIT) {
+      @SuppressWarnings("unchecked")
+      final Node<N, E>[] arr = new Node[] { elem };
+      return left ? DeepTree.get(nodes, arr) : DeepTree.get(arr, nodes);
+    }
+
+    final FingerTree<N, E> tree = buildTree(nodes, nodes.length, sz);
+    return left ? tree.snoc(elem) : tree.cons(elem);
+  }
+
+  @Override
+  public FingerTree<N, E> replaceHead(final Node<N, E> head) {
+    return new SingletonTree<>(head);
+  }
+
+  @Override
+  public FingerTree<N, E> replaceLast(final Node<N, E> head) {
+    return new SingletonTree<>(head);
+  }
+
+  @Override
+  void toString(final StringBuilder sb, final int indent) {
+    for(int i = 0; i < indent; i++) sb.append("  ");
+    sb.append("Single[\n");
+    toString(elem, sb, indent + 1);
+    sb.append("\n");
+    for(int i = 0; i < indent; i++) sb.append("  ");
+    sb.append("]");
+  }
+
+  @Override
+  public long checkInvariants() {
+    return elem.checkInvariants();
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/fingertree/TreeSlice.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/fingertree/TreeSlice.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/fingertree/TreeSlice.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/fingertree/TreeSlice.java	2015-07-14 10:54:40.000000000 +0000
@@ -14,24 +14,22 @@
   /** A full sub-tree. */
   private FingerTree<N, E> tree;
   /** A partial node. */
-  private PartialNode<N, E> partial;
+  private NodeLike<N, E> partial;
 
   /**
    * Constructor for whole trees.
    * @param tree the tree
    */
   TreeSlice(final FingerTree<N, E> tree) {
-    this.tree = tree;
-    this.partial = null;
+    setTree(tree);
   }
 
   /**
-   * Constructor for partial nodes.
+   * Constructor for potentially partial nodes.
    * @param partial partial node
    */
-  TreeSlice(final PartialNode<N, E> partial) {
-    this.tree = null;
-    this.partial = partial;
+  TreeSlice(final NodeLike<N, E> partial) {
+    setNodeLike(partial);
   }
 
   /**
@@ -57,7 +55,7 @@
    * returns {@code false}.
    * @return the contained partial node
    */
-  public PartialNode<N, E> getPartial() {
+  public NodeLike<N, E> getPartial() {
     return partial;
   }
 
@@ -77,17 +75,22 @@
   }
 
   /**
-   * Sets the contents of this slice to the given partial node and returns it with the correct type.
+   * Sets the contents of this slice to the given node and returns it with the correct type.
    * The value with the current type is invalid afterwards and should <i>not</i> be used.
    * @param <M> new node type
-   * @param newPartial new contents
+   * @param newNode new contents
    * @return type-cast version of this slice
    */
-  <M> TreeSlice<M, E> setPartial(final PartialNode<M, E> newPartial) {
+  <M> TreeSlice<M, E> setNodeLike(final NodeLike<M, E> newNode) {
     @SuppressWarnings("unchecked")
     final TreeSlice<M, E> out = (TreeSlice<M, E>) this;
-    out.partial = newPartial;
-    out.tree = null;
+    if(newNode instanceof Node) {
+      out.partial = null;
+      out.tree = new SingletonTree<>((Node<M, E>) newNode);
+    } else {
+      out.partial = newNode;
+      out.tree = null;
+    }
     return out;
   }
 
@@ -100,14 +103,10 @@
    * @return type-cast version of this slice
    */
   <M> TreeSlice<M, E> setNodes(final NodeLike<M, E>[] arr, final int n, final long size) {
-    if(n == 1) {
-      if(arr[0] instanceof PartialNode) return setPartial((PartialNode<M, E>) arr[0]);
-      final Node<M, E> node = (Node<M, E>) arr[0];
-      return setTree(new Single<>(node));
-    }
-
+    if(n == 0) return setTree(EmptyTree.<M, E>getInstance());
+    if(n == 1) return setNodeLike(arr[0]);
     final int mid = n / 2;
-    final Node<M, E>[] left = Deep.slice(arr, 0, mid), right = Deep.slice(arr, mid, n);
-    return setTree(Deep.get(left, right, size));
+    final Node<M, E>[] left = DeepTree.slice(arr, 0, mid), right = DeepTree.slice(arr, mid, n);
+    return setTree(DeepTree.get(left, right, size));
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/format/DecFormatter.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/format/DecFormatter.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/format/DecFormatter.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/format/DecFormatter.java	2015-07-14 10:54:40.000000000 +0000
@@ -102,14 +102,20 @@
     // check for duplicate characters
     zero = z;
     final IntSet is = new IntSet();
-    final int[] ss = { decimal, grouping, exponent, percent, permille, zero, optional, pattern };
+    for(int i = 0; i < 10; i++) is.add(zero + i);
+    final int[] ss = { decimal, grouping, exponent, percent, permille, optional, pattern };
     for(final int s : ss) if(!is.add(s)) throw DUPLDECFORM_X.get(info, (char) s);
 
     // create auxiliary strings
     final TokenBuilder tb = new TokenBuilder();
     for(int i = 0; i < 10; i++) tb.add(zero + i);
     digits = tb.toArray();
-    actives = tb.add(decimal).add(grouping).add(optional).add(exponent).finish();
+    // "decimal-separator-sign, exponent-separator-sign, grouping-sign, decimal-digit-family,
+    // optional-digit-sign and pattern-separator-sign are classified as active characters"
+    // -> decimal-digit-family: added above. pattern-separator-sign: will never occur at this stage
+    actives = tb.add(decimal).add(exponent).add(grouping).add(optional).finish();
+    // "all other characters (including the percent-sign and per-mille-sign) are classified
+    // as passive characters."
   }
 
   /**
@@ -126,19 +132,22 @@
     // find pattern separator and sub-patterns
     final TokenList tl = new TokenList();
     byte[] pic = picture;
+    // "A picture-string consists either of a sub-picture, or of two sub-pictures separated by
+    // a pattern-separator-sign"
     final int i = indexOf(pic, pattern);
     if(i == -1) {
       tl.add(pic);
     } else {
       tl.add(substring(pic, 0, i));
       pic = substring(pic, i + cl(pic, i));
+      // "A picture-string must not contain more than one pattern-separator-sign"
       if(contains(pic, pattern)) throw PICNUM_X.get(info, picture);
       tl.add(pic);
     }
     final byte[][] patterns = tl.finish();
 
     // check and analyze patterns
-    if(!check(patterns)) throw PICNUM_X.get(info, picture);
+    if(!checkSyntax(patterns)) throw PICNUM_X.get(info, picture);
     final Picture[] pics = analyze(patterns);
 
     // return formatted string
@@ -150,69 +159,102 @@
    * @param patterns patterns
    * @return result of check
    */
-  private boolean check(final byte[][] patterns) {
+  private boolean checkSyntax(final byte[][] patterns) {
     for(final byte[] pt : patterns) {
-      boolean frac = false, pas = false, act = false, exp = false;
-      boolean dg = false, opt1 = false, opt2 = false;
-      int cl, pc = 0, pm = 0, ls = 0;
+      boolean frac = false, act = false, expAct = false, exp = false, digMant = false;
+      boolean optInt = false, optFrac = false, per = false;
+      int cl, last = 0;
 
       // loop through all characters
       final int pl = pt.length;
       for(int i = 0; i < pl; i += cl) {
         final int ch = ch(pt, i);
         cl = cl(pt, i);
-        boolean active = contains(actives, ch);
         final boolean digit = contains(digits, ch);
-        if(exp && !digit) return false;
+        boolean active = contains(actives, ch), expon = false;
 
         if(ch == decimal) {
-          // more than 1 decimal sign?
+          // "A sub-picture must not contain more than one decimal-separator-sign."
           if(frac) return false;
           frac = true;
         } else if(ch == grouping) {
-          // adjacent decimal sign?
-          if(i == 0 && frac || ls == decimal || i + cl < pl ? ch(pt, i + cl) == decimal : !frac)
+          // "A sub-picture must not contain a grouping-separator-sign that appears adjacent to a
+          // decimal-separator-sign, or in the absence of a decimal-separator-sign, at the end of
+          // the integer part."
+          if(i == 0 && frac || last == decimal || (i + cl < pl ? ch(pt, i + cl) == decimal : !frac))
             return false;
+          // "A sub-picture must not contain two adjacent grouping-separator-signs."
+          if(last == grouping) return false;
         } else if(ch == exponent) {
-          if(contains(actives, ls) && contains(actives, ch(pt, i + cl))) {
-            // more than one exponent sign
+          // "A character that matches the chosen exponent-separator-sign is treated as an
+          // exponent-separator-sign if it is both preceded and followed within the sub-picture by
+          // an active character."
+          if(act && containsActive(pt, i + cl)) {
+            // "A sub-picture must not contain more than one character that is treated as an
+            // exponent-separator-sign."
             if(exp) return false;
-            exp = true;
+            expon = true;
           } else {
+            // "Otherwise, it is treated as a passive character."
             active = false;
           }
-        } else if(ch == percent) {
-          ++pc;
-        } else if(ch == permille) {
-          ++pm;
+        } else if(ch == percent || ch == permille) {
+          // "A sub-picture must not contain more than one percent-sign or per-mille-sign,
+          // and it must not contain one of each."
+          if(per) return false;
+          per = true;
         } else if(ch == optional) {
           if(frac) {
-            opt2 = true;
+            optFrac = true;
           } else {
-            // integer part, and optional sign after digit?
-            if(dg) return false;
-            opt1 = true;
+            // "The integer part of a sub-picture must not contain a member of the decimal-digit-
+            // family that is followed by an optional-digit-sign."
+            if(digMant) return false;
+            optInt = true;
           }
         } else if(digit) {
-          // fractional part, and digit after optional sign?
-          if(frac && opt2) return false;
-          dg = true;
+          if(!exp) {
+            // "The fractional part of a sub-picture must not contain an optional-digit-sign that
+            // is followed by a member of the decimal-digit-family."
+            if(optFrac) return false;
+            digMant = true;
+          }
+        }
+
+        if(active) {
+          // "If a sub-picture contains a character treated as an exponent-separator-sign then
+          // this must be followed by one or more characters that are members of the
+          // decimal-digit-family, and it must not be followed by any active character that is not
+          // a member of the decimal-digit-family." (*)
+          if(exp) {
+            if(!digit) return false;
+            expAct = true;
+          }
+          act = true;
+        } else {
+          // "A sub-picture must not contain a passive character that is preceded by an active
+          // character and that is followed by another active character."
+          if(act && containsActive(pt, i + cl)) return false;
         }
 
-        // passive character with preceding and following active character?
-        if(active && pas && act) return false;
-        // will be assigned if active characters were found
-        if(act) pas |= !active;
-        act |= active;
         // cache last character
-        ls = ch;
+        last = ch;
+        if(expon) exp = true;
       }
 
-      // percent and permille sign: more than 1, or exponent sign?
-      if(pc + pm > (exp ? 0 : 1)) return false;
-      // no optional sign or digit?
-      if(!opt1 && !opt2 && !dg) return false;
+      // "The mantissa part of a sub-picture must contain at least one character that is an
+      // optional-digit-sign or a member of the decimal-digit-family."
+      if(!optInt && !optFrac && !digMant) return false;
+
+      // "A sub-picture that contains a percent-sign or per-mille-sign must not contain a character
+      // treated as an exponent-separator-sign."
+      if(per && exp) return false;
+
+      // (*) continued
+      if(exp && !expAct) return false;
     }
+
+    // everything ok
     return true;
   }
 
@@ -223,11 +265,11 @@
    */
   private Picture[] analyze(final byte[][] patterns) {
     // pictures
-    final int pl = patterns.length;
-    final Picture[] pics = new Picture[pl];
+    final int picL = patterns.length;
+    final Picture[] pics = new Picture[picL];
 
     // analyze patterns
-    for(int p = 0; p < pl; p++) {
+    for(int p = 0; p < picL; p++) {
       final byte[] pt = patterns[p];
       final Picture pic = new Picture();
 
@@ -241,8 +283,8 @@
       final int[] opt = new int[2];
 
       // loop through all characters
-      final int ptl = pt.length;
-      for(int i = 0, cl; i < ptl; i += cl) {
+      final int pl = pt.length;
+      for(int i = 0, cl; i < pl; i += cl) {
         final int ch = ch(pt, i);
         cl = cl(pt, i);
         boolean active = contains(actives, ch);
@@ -253,15 +295,9 @@
         } else if(ch == optional) {
           opt[pos]++;
         } else if(ch == exponent) {
-          // check if following characters are all digits
-          boolean e = true;
-          for(int c = i + cl; c < ptl && e; c += cl(pt, c)) e = contains(digits, ch(pt, c));
-          if(e && i + cl < ptl) {
-            // test succeeds, exponent sign found
+          if(act && containsActive(pt, i + cl)) {
             exp = 0;
           } else {
-            // passive character: add to prefixes/suffixes
-            pic.xyzfix[pos == 0 && act ? pos + 1 : pos].add(ch);
             active = false;
           }
         } else if(ch == grouping) {
@@ -269,14 +305,17 @@
         } else if(contains(digits, ch)) {
           if(exp == -1) pic.min[pos]++;
           else exp++;
+        }
+
+        if(active) {
+          act = true;
         } else {
           // passive characters
           pic.pc |= ch == percent;
           pic.pm |= ch == permille;
           // prefixes/suffixes
-          pic.xyzfix[pos == 0 && act ? pos + 1 : pos].add(ch);
+          pic.prefSuf[pos == 0 && act ? pos + 1 : pos].add(ch);
         }
-        act |= active;
       }
       // finalize integer-part-grouping-positions
       final int[] igp = pic.group[0];
@@ -300,6 +339,19 @@
   }
 
   /**
+   * Checks if the specified pattern contains active characters after the specified index.
+   * @param pt pattern
+   * @param i index
+   * @return result of check
+   */
+  private boolean containsActive(final byte[] pt, final int i) {
+    for(int p = i; p < pt.length; p += cl(pt, p)) {
+      if(contains(actives, ch(pt, p))) return true;
+    }
+    return false;
+  }
+
+  /**
    * Formats the specified number and returns a string representation.
    * @param it item
    * @param pics pictures
@@ -310,44 +362,48 @@
   private byte[] format(final ANum it, final Picture[] pics, final InputInfo ii)
       throws QueryException {
 
-    // return results for NaN
+    // Rule 1: return results for NaN
     final double d = it.dbl(ii);
     if(Double.isNaN(d)) return nan;
 
-    // return infinite results
+    // Rule 2: check if value if negative (smaller than zero or -0)
     final boolean neg = d < 0 || d == 0 && Double.doubleToLongBits(d) == Long.MIN_VALUE;
     final Picture pic = pics[neg && pics.length == 2 ? 1 : 0];
-    final TokenBuilder res = new TokenBuilder();
-    final TokenBuilder intgr = new TokenBuilder();
-    final TokenBuilder fract = new TokenBuilder();
+    final IntList res = new IntList(), intgr = new IntList(), fract = new IntList();
     int exp = 0;
 
-    if(d == Double.POSITIVE_INFINITY || d == Double.NEGATIVE_INFINITY) {
-      intgr.add(inf);
+    if(Double.isInfinite(d)) {
+      // Rule 3
+      intgr.add(new TokenParser(inf).toArray());
     } else {
       // convert and round number
       ANum num = it;
+      // Rule 4
       if(pic.pc) num = (ANum) Calc.MULT.ev(ii, num, Int.get(100));
       if(pic.pm) num = (ANum) Calc.MULT.ev(ii, num, Int.get(1000));
-      if(pic.minExp != 0) {
-        final String s = (num instanceof Dbl || num instanceof Flt ?
-          Dec.get(num.dbl(ii)) : num).abs().toString();
-        final int sep = s.indexOf('.');
-        final int i = sep == -1 ? s.length() : sep;
-        final int m = pic.min[0];
-        double n = 1;
-        exp = i - m;
-        if(exp > 0) {
-          for(int a = exp; a-- > 0;) n *= 10;
-          num = (ANum) Calc.DIV.ev(ii, num, Dec.get(n));
+      // Rule 5
+      if(pic.minExp != 0 && d != 0) {
+        BigDecimal dec = num.dec(ii).abs().stripTrailingZeros();
+        int scl = 0;
+        if(dec.compareTo(BigDecimal.ONE) >= 0) {
+          scl = dec.setScale(0, RoundingMode.HALF_DOWN).precision();
         } else {
-          for(int a = -exp; a-- > 0;) n *= 10;
-          num = (ANum) Calc.MULT.ev(ii, num, Dec.get(n));
+          while(dec.compareTo(BigDecimal.ONE) < 0) {
+            dec = dec.multiply(BigDecimal.TEN);
+            scl--;
+          }
+          scl++;
+        }
+
+        exp = scl - pic.min[0];
+        if(exp != 0) {
+          final BigDecimal n = BigDecimal.TEN.pow(Math.abs(exp));
+          num = (ANum) Calc.MULT.ev(ii, num, Dec.get(exp > 0 ? BigDecimal.ONE.divide(n) : n));
         }
       }
       num = num.round(pic.maxFrac, true).abs();
 
-      // convert positive number to string, chop leading zero
+      // convert positive number to string
       final String s = (num instanceof Dbl || num instanceof Flt ?
           Dec.get(BigDecimal.valueOf(num.dbl(ii))) : num).toString();
 
@@ -358,14 +414,14 @@
       final int sl = s.length();
       final int il = sep == -1 ? sl : sep;
       for(int i = il; i < pic.min[0]; ++i) intgr.add(zero);
-      for(int i = 0; i < il; i++) intgr.add(zero + s.charAt(i) - '0');
+      // fractional number: skip leading 0
+      if(!s.startsWith("0.")) for(int i = 0; i < il; i++) intgr.add(zero + s.charAt(i) - '0');
 
       // squeeze in grouping separators
-      if(pic.group[0].length == 1) {
+      if(pic.group[0].length == 1 && pic.group[0][0] > 0) {
         // regular pattern with repeating separators
-        final int pos = pic.group[0][0];
         for(int p = intgr.size() - (neg ? 2 : 1); p > 0; --p) {
-          if(p % pos == 0) intgr.insert(intgr.size() - p, grouping);
+          if(p % pic.group[0][0] == 0) intgr.insert(intgr.size() - p, grouping);
         }
       } else {
         // irregular pattern, or no separators at all
@@ -392,11 +448,9 @@
     // add minus sign
     if(neg && pics.length != 2) res.add(minus);
     // add prefix and integer part
-    res.add(pic.xyzfix[0].toArray()).add(intgr.finish());
+    res.add(pic.prefSuf[0].toArray()).add(intgr.finish());
     // add fractional part
     if(!fract.isEmpty()) res.add(decimal).add(fract.finish());
-    // add suffix
-    res.add(pic.xyzfix[1].toArray());
     // add exponent
     if(pic.minExp != 0) {
       res.add(exponent);
@@ -406,13 +460,15 @@
       for(int i = sl; i < pic.minExp; i++) res.add(zero);
       for(int i = 0; i < sl; i++) res.add(zero + s.charAt(i) - '0');
     }
-    return res.finish();
+    // add suffix
+    res.add(pic.prefSuf[1].toArray());
+    return new TokenBuilder(res.finish()).finish();
   }
 
   /** Picture variables. */
   private static final class Picture {
     /** Prefix/suffix. */
-    private final TokenBuilder[] xyzfix = { new TokenBuilder(), new TokenBuilder() };
+    private final IntList[] prefSuf = { new IntList(), new IntList() };
     /** Integer/fractional-part-grouping-positions. */
     private final int[][] group = { {}, {} };
     /** Minimum-integer/fractional-part-size. */
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/format/Formatter.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/format/Formatter.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/format/Formatter.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/format/Formatter.java	2015-07-14 10:54:40.000000000 +0000
@@ -5,7 +5,6 @@
 
 import java.math.*;
 import java.util.*;
-import java.util.regex.*;
 
 import org.basex.query.*;
 import org.basex.query.value.item.*;
@@ -21,8 +20,6 @@
  * @author Christian Gruen
  */
 public abstract class Formatter extends FormatUtil {
-  /** Calendar pattern. */
-  private static final Pattern CALENDAR = Pattern.compile("(Q\\{([^}]*)\\})?([^}]+)");
   /** Military timezones. */
   private static final byte[] MIL = token("YXWVUTSRQPONZABCDEFGHIKLM");
   /** Token: Nn. */
@@ -132,10 +129,8 @@
     if(lng.length != 0 && MAP.get(lng) == null) tb.add("[Language: en]");
     boolean iso = false;
     if(cal.length != 0) {
-      final Matcher m = CALENDAR.matcher(string(cal));
-      if(!m.matches()) throw CALQNAME_X.get(ii, cal);
-      final QNm qnm = new QNm(m.group(3), m.group(1) == null ||
-          m.group(2).isEmpty() ? null : m.group(2));
+      final QNm qnm = QNm.resolve(cal);
+      if(qnm == null) throw CALQNAME_X.get(ii, cal);
       if(!qnm.hasURI()) {
         int c = -1;
         final byte[] ln = qnm.local();
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/ft/FTMatches.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/ft/FTMatches.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/ft/FTMatches.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/ft/FTMatches.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,130 @@
+package org.basex.query.util.ft;
+
+import java.util.*;
+
+import org.basex.util.*;
+import org.basex.util.list.*;
+
+/**
+ * AllMatches full-text container, referencing several {@link FTMatch} instances.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Christian Gruen
+ */
+public final class FTMatches extends ElementList implements Iterable<FTMatch> {
+  /** Full-text matches. */
+  public FTMatch[] match = {};
+  /** Position of a token in the query. */
+  public int pos;
+
+  /**
+   * Constructor.
+   */
+  public FTMatches() {
+  }
+
+  /**
+   * Constructor.
+   * @param pos query position
+   */
+  public FTMatches(final int pos) {
+    this.pos = pos;
+  }
+
+  /**
+   * Resets the match container.
+   * @param ps query position
+   */
+  public void reset(final int ps) {
+    pos = ps;
+    size = 0;
+  }
+
+  /**
+   * Adds a match entry.
+   * @param ps position
+   */
+  public void or(final int ps) {
+    or(ps, ps);
+  }
+
+  /**
+   * Adds a match entry.
+   * @param start start position
+   * @param end end position
+   */
+  public void or(final int start, final int end) {
+    add(new FTMatch(1).add(new FTStringMatch(start, end, pos)));
+  }
+
+  /**
+   * Adds a match entry.
+   * @param start start position
+   * @param end end position
+   */
+  public void and(final int start, final int end) {
+    final FTStringMatch sm = new FTStringMatch(start, end, pos);
+    for(final FTMatch m : this) m.add(sm);
+  }
+
+  /**
+   * Adds a match entry.
+   * @param ftm match to be added
+   */
+  public void add(final FTMatch ftm) {
+    if(size == match.length) match = Array.copy(match, new FTMatch[Array.newSize(size)]);
+    match[size++] = ftm;
+  }
+
+  /**
+   * Removes the specified match.
+   * @param index match index
+   */
+  public void delete(final int index) {
+    Array.move(match, index + 1, -1, --size - index);
+  }
+
+  /**
+   * Checks if at least one of the matches contains only includes.
+   * @return result of check
+   */
+  public boolean matches() {
+    for(final FTMatch m : this) if(m.match()) return true;
+    return false;
+  }
+
+  /**
+   * Combines two matches as phrase.
+   * @param all second match list
+   * @param distance word distance
+   * @return true if matches are left
+   */
+  public boolean phrase(final FTMatches all, final int distance) {
+    int a = 0, b = 0, c = 0;
+    while(a < size && b < all.size) {
+      final int e = all.match[b].match[0].start;
+      final int d = e - match[a].match[0].end - distance;
+      if(d == 0) {
+        match[c] = match[a];
+        match[c++].match[0].end = e;
+      }
+      if(d >= 0) ++a;
+      if(d <= 0) ++b;
+    }
+    size = c;
+    return size != 0;
+  }
+
+  @Override
+  public Iterator<FTMatch> iterator() {
+    return new ArrayIterator<>(match, size);
+  }
+
+  @Override
+  public String toString() {
+    final StringBuilder sb = new StringBuilder();
+    sb.append(Util.className(this)).append('[').append(pos).append(']');
+    for(final FTMatch m : this) sb.append("\n  ").append(m);
+    return sb.toString();
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/ft/FTMatch.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/ft/FTMatch.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/ft/FTMatch.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/ft/FTMatch.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,95 @@
+package org.basex.query.util.ft;
+
+import java.util.*;
+
+import org.basex.util.*;
+import org.basex.util.list.*;
+
+/**
+ * Match full-text container, referencing several {@link FTStringMatch} instances.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Christian Gruen
+ */
+public final class FTMatch extends ElementList implements Iterable<FTStringMatch> {
+  /** String matches. */
+  FTStringMatch[] match;
+
+  /**
+   * Constructor.
+   */
+  public FTMatch() {
+    this(0);
+  }
+
+  /**
+   * Constructor, specifying an initial internal array size.
+   * @param capacity initial array capacity
+   */
+  public FTMatch(final int capacity) {
+    match = new FTStringMatch[capacity];
+  }
+
+  /**
+   * Adds all matches of a full-text match.
+   * @param ftm match to be added
+   * @return self reference
+   */
+  public FTMatch add(final FTMatch ftm) {
+    for(final FTStringMatch sm : ftm) add(sm);
+    return this;
+  }
+
+  /**
+   * Adds a single string match.
+   * @param ftm match to be added
+   * @return self reference
+   */
+  public FTMatch add(final FTStringMatch ftm) {
+    if(size == match.length) match = Array.copy(match, new FTStringMatch[newSize()]);
+    match[size++] = ftm;
+    return this;
+  }
+
+  /**
+   * Checks if the full-text match is not part of the specified match.
+   * @param ftm match to be checked
+   * @return result of check
+   */
+  public boolean notin(final FTMatch ftm) {
+    for(final FTStringMatch s : this) {
+      for(final FTStringMatch sm : ftm) if(!s.in(sm)) return true;
+    }
+    return false;
+  }
+
+  /**
+   * Checks if the match contains no string excludes.
+   * @return result of check
+   */
+  boolean match() {
+    for(final FTStringMatch s : this) if(s.exclude) return false;
+    return true;
+  }
+
+  /**
+   * Sorts the matches by their start and end positions.
+   */
+  public void sort() {
+    Arrays.sort(match, 0, size, null);
+  }
+
+  @Override
+  public Iterator<FTStringMatch> iterator() {
+    return new ArrayIterator<>(match, size);
+  }
+
+  @Override
+  public String toString() {
+    final StringBuilder sb = new StringBuilder();
+    for(final FTStringMatch s : this) {
+      sb.append(sb.length() == 0 ? "" : ", ").append(s);
+    }
+    return Util.className(this) + ' ' + sb;
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/ft/FTPosData.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/ft/FTPosData.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/ft/FTPosData.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/ft/FTPosData.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,113 @@
+package org.basex.query.util.ft;
+
+import java.util.*;
+
+import org.basex.data.*;
+import org.basex.util.*;
+import org.basex.util.hash.*;
+import org.basex.util.list.*;
+
+/**
+ * This class provides a container for query full-text positions,
+ * which is evaluated by the visualizations.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Christian Gruen
+ * @author Sebastian Gath
+ */
+public final class FTPosData {
+  /** Position references. */
+  private FTPos[] pos = new FTPos[1];
+  /** Data reference. */
+  private Data dt;
+  /** Number of values. */
+  private int size;
+
+  /**
+   * Adds position data.
+   *
+   * @param data data reference
+   * @param pre pre value
+   * @param all full-text matches
+   */
+  public void add(final Data data, final int pre, final FTMatches all) {
+    if(dt == null) dt = data;
+    else if(dt != data) return;
+
+    // cache all positions
+    final IntSet set = new IntSet();
+    for(final FTMatch ftm : all) {
+      for(final FTStringMatch sm : ftm) {
+        for(int s = sm.start; s <= sm.end; ++s) set.add(s);
+      }
+    }
+
+    // sort and store all positions
+    final IntList il = new IntList(set.toArray()).sort();
+    int c = find(pre);
+    if(c < 0) {
+      c = -c - 1;
+      if(size == pos.length) pos = Arrays.copyOf(pos, Array.newSize(size));
+      Array.move(pos, c, 1, size++ - c);
+      pos[c] = new FTPos(pre, il);
+    } else {
+      pos[c].union(il);
+    }
+  }
+
+  /**
+   * Gets full-text data from the container.
+   * If no data is stored for a pre value, {@code null} is returned.
+   * int[0] : [pos0, ..., posn]
+   * int[1] : [poi0, ..., poin]
+   * @param data data reference
+   * @param pre int pre value
+   * @return int[2][n] full-text data or {@code null}
+   */
+  public FTPos get(final Data data, final int pre) {
+    final int p = find(pre);
+    return p < 0 || dt != data ? null : pos[p];
+  }
+
+  /**
+   * Returns the number of entries.
+   * @return size
+   */
+  public int size() {
+    int c = 0;
+    for(int i = 0; i < size; ++i) c += pos[i].size();
+    return c;
+  }
+
+  /**
+   * Compares full-text position data.
+   * @param ft data to be compared
+   * @return result of check
+   */
+  public boolean sameAs(final FTPosData ft) {
+    if(size != ft.size) return false;
+    for(int i = 0; i < size; ++i) {
+      if(pos[i].pre != ft.pos[i].pre || !Arrays.equals(
+          pos[i].list.toArray(), ft.pos[i].list.toArray())) return false;
+    }
+    return true;
+  }
+
+  /**
+   * Returns the index of the specified pre value.
+   * @param pre int pre value
+   * @return index, or negative index - 1 if pre value is not found
+   */
+  private int find(final int pre) {
+    // binary search
+    int l = 0, h = size - 1;
+    while(l <= h) {
+      final int m = l + h >>> 1;
+      final int c = pos[m].pre - pre;
+      if(c == 0) return m;
+      if(c < 0) l = m + 1;
+      else h = m - 1;
+    }
+    return -l - 1;
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/ft/FTPos.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/ft/FTPos.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/ft/FTPos.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/ft/FTPos.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,61 @@
+package org.basex.query.util.ft;
+
+import org.basex.util.hash.*;
+import org.basex.util.list.*;
+
+/**
+ * This class contains full-text positions for a single database node.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Christian Gruen
+ */
+public final class FTPos {
+  /** Pre value. */
+  final int pre;
+  /** Positions. */
+  IntList list;
+
+  /**
+   * Constructor.
+   * @param pre pre value
+   * @param list sorted positions
+   */
+  FTPos(final int pre, final IntList list) {
+    this.pre = pre;
+    this.list = list;
+  }
+
+  /**
+   * Merges the specified position arrays.
+   * @param pos sorted positions
+   */
+  void union(final IntList pos) {
+    final int ps = list.size(), ls = pos.size();
+    final IntSet set = new IntSet(ps + ls);
+    for(int p = 0, s = ps; p < s; p++) set.add(list.get(p));
+    for(int l = 0, s = ls; l < s; l++) set.add(pos.get(l));
+    list = new IntList(set.toArray()).sort();
+  }
+
+  /**
+   * Checks if the specified position is found.
+   * @param pos position to be found
+   * @return result of check
+   */
+  public boolean contains(final int pos) {
+    return list.sortedIndexOf(pos) >= 0;
+  }
+
+  /**
+   * Returns the number of positions.
+   * @return number of positions
+   */
+  public int size() {
+    return list.size();
+  }
+
+  @Override
+  public String toString() {
+    return pre + ": " + list;
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/ft/FTStringMatch.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/ft/FTStringMatch.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/ft/FTStringMatch.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/ft/FTStringMatch.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,67 @@
+package org.basex.query.util.ft;
+
+/**
+ * Single full-text string match.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Christian Gruen
+ */
+public final class FTStringMatch implements Comparable<FTStringMatch> {
+  /** Position of the token in the query. */
+  public final int pos;
+  /** Start position. */
+  public final int start;
+  /** End position. */
+  public int end;
+  /** Exclude flag. */
+  public boolean exclude;
+  /** Gaps (non-contiguous) flag. */
+  public boolean gaps;
+
+  /**
+   * Constructor.
+   * @param start start position
+   * @param end end position
+   * @param pos query pos
+   */
+  FTStringMatch(final int start, final int end, final int pos) {
+    this.start = start;
+    this.end = end;
+    this.pos = pos;
+  }
+
+  /**
+   * Checks if the match is included in the specified match.
+   * @param mtc match to be compared
+   * @return result of check
+   */
+  boolean in(final FTStringMatch mtc) {
+    return start >= mtc.start && end <= mtc.end;
+  }
+
+  @Override
+  public boolean equals(final Object ftm) {
+    if(!(ftm instanceof FTStringMatch)) return false;
+    final FTStringMatch sm = (FTStringMatch) ftm;
+    return start == sm.start && end == sm.end;
+  }
+
+  @Override
+  public int compareTo(final FTStringMatch sm) {
+    final int s = start - sm.start;
+    return s == 0 ? end - sm.end : s;
+  }
+
+  @Override
+  public int hashCode() {
+    final int h = start + 1;
+    return (h << 5) - h + end;
+  }
+
+  @Override
+  public String toString() {
+    final StringBuilder sb = new StringBuilder().append(pos);
+    sb.append(':').append(start).append('-').append(end);
+    return exclude ? "not(" + sb + ')' : sb.toString();
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/IndexInfo.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/IndexInfo.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/IndexInfo.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/IndexInfo.java	2015-07-14 10:54:40.000000000 +0000
@@ -57,7 +57,7 @@
 
   /**
    * Checks if the specified expression can be rewritten for index access.
-   * @param ex expression (must be {@link Context} or {@link AxisPath})
+   * @param ex expression (must be {@link ContextValue} or {@link AxisPath})
    * @param ft full-text flag
    * @return location step or {@code null}
    */
@@ -66,7 +66,7 @@
 
     // context reference: work with index step
     Step s = step;
-    if(!(ex instanceof Context)) {
+    if(!(ex instanceof ContextValue)) {
       // check if index can be applied
       if(!(ex instanceof AxisPath)) return false;
       // accept only single axis steps as first expression
@@ -82,7 +82,7 @@
     final boolean elem = s.test.type == NodeType.ELM;
     if(elem) {
       // only do check if database is up-to-date if no namespaces occur and if name test is used
-      if(!data.meta.uptodate || data.nspaces.size() != 0 || s.test.kind != Kind.NAME) return false;
+      if(!data.meta.uptodate || !data.nspaces.isEmpty() || s.test.kind != Kind.NAME) return false;
       test = (NameTest) s.test;
       final Stats stats = data.elemNames.stat(data.elemNames.id(test.name.local()));
       if(stats == null || !stats.isLeaf()) return false;
@@ -119,7 +119,7 @@
    */
   private ParseExpr invert(final ParseExpr root) {
     // handle context node
-    if(orig instanceof Context) {
+    if(orig instanceof ContextValue) {
       // add attribute step
       if(!attr || step.test.name == null) return root;
       final Step as = Step.get(step.info, Axis.SELF, step.test);
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/list/AnnList.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/list/AnnList.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/list/AnnList.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/list/AnnList.java	2015-07-14 10:54:40.000000000 +0000
@@ -79,20 +79,22 @@
     final AnnList tmp = new AnnList();
     boolean pub = false, priv = false, up = false;
     for(final Ann ann : this) {
-      if(ann.sig == Annotation.PUBLIC) pub = true;
-      else if(ann.sig == Annotation.PRIVATE) priv = true;
-      else if(ann.sig == Annotation.UPDATING) up = true;
+      final Annotation sig = ann.sig;
+      if(sig == Annotation.PUBLIC) pub = true;
+      else if(sig == Annotation.PRIVATE) priv = true;
+      else if(sig == Annotation.UPDATING) up = true;
       tmp.add(ann);
     }
 
     for(final Ann ann : al) {
-      if(ann.sig == Annotation.PUBLIC) {
+      final Annotation sig = ann.sig;
+      if(sig == Annotation.PUBLIC) {
         if(pub) continue;
         if(priv) return null;
-      } else if(ann.sig == Annotation.PRIVATE) {
+      } else if(sig == Annotation.PRIVATE) {
         if(pub) return null;
         if(priv) continue;
-      } else if(ann.sig == Annotation.UPDATING && up) {
+      } else if(sig == Annotation.UPDATING && up) {
         continue;
       }
       tmp.add(ann);
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/list/ANodeList.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/list/ANodeList.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/list/ANodeList.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/list/ANodeList.java	2015-07-14 10:54:40.000000000 +0000
@@ -2,15 +2,18 @@
 
 import java.util.*;
 
+import org.basex.data.*;
+import org.basex.query.iter.*;
 import org.basex.query.value.*;
 import org.basex.query.value.node.*;
-import org.basex.query.value.seq.*;
 import org.basex.query.value.type.*;
 import org.basex.util.*;
 import org.basex.util.list.*;
 
 /**
- * This is a light-weight container for XML nodes.
+ * Resizable-array implementation for nodes. If the {@link #check} function is called, the stored
+ * nodes will be sorted and duplicates will before removed before they are returned as value or
+ * via an iterator.
  *
  * @author BaseX Team 2005-15, BSD License
  * @author Christian Gruen
@@ -18,6 +21,10 @@
 public final class ANodeList extends ElementList implements Iterable<ANode> {
   /** Element container. */
   private ANode[] list;
+  /** Sort flag. */
+  private boolean sort;
+  /** Check incoming nodes for potential duplicates and unsorted entries. */
+  private boolean check;
 
   /**
    * Constructor.
@@ -28,70 +35,298 @@
 
   /**
    * Constructor, specifying an initial array capacity.
-   * @param c array capacity
+   * @param capacity array capacity
    */
-  public ANodeList(final int c) {
-    list = new ANode[c];
+  public ANodeList(final int capacity) {
+    list = new ANode[capacity];
   }
 
   /**
-   * Constructor, specifying initial nodes.
-   * @param n initial nodes
+   * Lightweight constructor, assigning the specified array.
+   * @param elements initial array
    */
-  public ANodeList(final ANode... n) {
-    list = n;
-    size = n.length;
+  public ANodeList(final ANode... elements) {
+    list = elements;
+    size = elements.length;
+  }
+
+  /**
+   * Checks all nodes for potential duplicates and orderedness.
+   * @return self reference
+   */
+  public ANodeList check() {
+    check = true;
+    return this;
   }
 
   /**
    * Adds an element to the array.
-   * @param e element to be added
+   * @param element element to be added
    */
-  public void add(final ANode e) {
-    if(size == list.length) copyOf(newSize());
-    list[size++] = e;
+  public void add(final ANode element) {
+    ANode[] lst = list;
+    final int s = size;
+    if(s == lst.length) lst = copyOf(newSize());
+    if(s != 0 && check && !sort) sort = lst[s - 1].diff(element) > 0;
+    lst[s] = element;
+    list = lst;
+    size = s + 1;
   }
 
   /**
    * Sets an element at the specified index position.
-   * @param i index
-   * @param e element to be set
+   * @param index index
+   * @param element element to be set
    */
-  public void set(final int i, final ANode e) {
-    if(i >= list.length) copyOf(newSize(i + 1));
-    list[i] = e;
-    size = Math.max(size, i + 1);
+  public void set(final int index, final ANode element) {
+    ANode[] lst = list;
+    if(index >= lst.length) lst = copyOf(newSize(index + 1));
+    lst[index] = element;
+    list = lst;
+    size = Math.max(size, index + 1);
   }
 
   /**
    * Returns the specified element.
-   * @param p position
-   * @return value
+   * @param index index
+   * @return element
+   */
+  public ANode get(final int index) {
+    return list[index];
+  }
+
+  /**
+   * Deletes the element at the specified position.
+   * @param index index of the element to delete
+   * @return deleted element
    */
-  public ANode get(final int p) {
-    return list[p];
+  public ANode delete(final int index) {
+    final ANode l = list[index];
+    Array.move(list, index + 1, -1, --size - index);
+    return l;
   }
 
   /**
-   * Returns an array with all elements.
+   * Returns a {@link Value} representation of all items.
    * @return array
    */
   public Value value() {
-    return Seq.get(list, size, NodeType.NOD);
+    sort();
+    return ValueBuilder.value(list, size, NodeType.NOD);
+  }
+
+  @Override
+  public Iterator<ANode> iterator() {
+    sort();
+    return new ArrayIterator<>(list, size);
+  }
+
+  /**
+   * Returns an iterator over the items in this list.
+   * The list must not be modified after the iterator has been requested.
+   * @return the iterator
+   */
+  public BasicNodeIter iter() {
+    sort();
+
+    return new BasicNodeIter() {
+      int pos;
+
+      @Override
+      public Value value() {
+        return ANodeList.this.value();
+      }
+
+      @Override
+      public long size() {
+        return size;
+      }
+
+      @Override
+      public ANode next() {
+        return pos < size ? list[pos++] : null;
+      }
+
+      @Override
+      public ANode get(final long i) {
+        return list[(int) i];
+      }
+    };
+  }
+
+  /**
+   * Sorts the nodes and checks if binary search can be applied to this iterator.
+   * This is the case if all nodes are {@link DBNode}s and refer to the same database.
+   * @return result of check
+   */
+  public boolean dbnodes() {
+    sort();
+
+    final int s = size;
+    final ANode[] lst = list;
+    final Data data = s > 0 ? lst[0].data() : null;
+    if(data == null) return false;
+    for(int l = 1; l < s; ++l) if(data != lst[l].data()) return false;
+    return true;
+  }
+
+  /**
+   * Checks if the iterator contains a database node with the specified pre value.
+   * @param node node to be found
+   * @param db indicates if all nodes are sorted {@link DBNode}s
+   * @return position, or {@code -1}
+   */
+  public int indexOf(final ANode node, final boolean db) {
+    if(db) return node instanceof DBNode ? Math.max(binarySearch((DBNode) node, 0, size), -1) : -1;
+
+    final long sz = size();
+    final ANode[] lst = list;
+    for(int s = 0; s < sz; ++s) if(lst[s].is(node)) return s;
+    return -1;
   }
 
   /**
-   * Resizes the array.
+   * Performs a binary search on the given range of this sequence iterator,
+   * assuming that all nodes are {@link DBNode}s from the same {@link Data}
+   * instance (i.e., {@link #dbnodes()} returns {@code true}).
+   * @param node node to find
+   * @param start start of the search interval
+   * @param length length of the search interval
+   * @return position of the item or {@code -insertPosition - 1} if not found
+   */
+  public int binarySearch(final DBNode node, final int start, final int length) {
+    if(size == 0 || node.data() != list[0].data()) return -start - 1;
+    int l = start, r = start + length - 1;
+    final ANode[] lst = list;
+    while(l <= r) {
+      final int m = l + r >>> 1, mpre = ((DBNode) lst[m]).pre(), npre = node.pre();
+      if(mpre == npre) return m;
+      if(mpre < npre) l = m + 1;
+      else r = m - 1;
+    }
+    return -(l + 1);
+  }
+
+  /**
+   * Creates a resized array.
    * @param s new size
+   * @return new array
    */
-  private void copyOf(final int s) {
+  private ANode[] copyOf(final int s) {
     final ANode[] tmp = new ANode[s];
     System.arraycopy(list, 0, tmp, 0, size);
-    list = tmp;
+    return tmp;
   }
 
-  @Override
-  public Iterator<ANode> iterator() {
-    return new ArrayIterator<>(list, size);
+  /**
+   * Sorts the nodes.
+   */
+  private void sort() {
+    if(!check) return;
+
+    final int s = size;
+    if(s > 1) {
+      if(sort) sort(0, s);
+
+      // remove duplicates
+      int i = 1;
+      final ANode[] lst = list;
+      for(int j = 1; j < s; ++j) {
+        while(j < s && lst[i - 1].is(lst[j])) j++;
+        if(j < s) lst[i++] = lst[j];
+      }
+      size = i;
+    }
+    check = false;
+  }
+
+  /**
+   * Recursively sorts the specified items via QuickSort
+   * (derived from Java's sort algorithms).
+   * @param s start position
+   * @param e end position
+   */
+  private void sort(final int s, final int e) {
+    if(e < 7) {
+      for(int i = s; i < e + s; ++i) {
+        for(int j = i; j > s && list[j - 1].diff(list[j]) > 0; j--) s(j, j - 1);
+      }
+      return;
+    }
+
+    int m = s + (e >> 1);
+    if(e > 7) {
+      int l = s;
+      int n = s + e - 1;
+      if(e > 40) {
+        final int k = e >>> 3;
+        l = m(l, l + k, l + (k << 1));
+        m = m(m - k, m, m + k);
+        n = m(n - (k << 1), n - k, n);
+      }
+      m = m(l, m, n);
+    }
+    final ANode v = list[m];
+
+    int a = s, b = a, c = s + e - 1, d = c;
+    while(true) {
+      while(b <= c) {
+        final int h = list[b].diff(v);
+        if(h > 0) break;
+        if(h == 0) s(a++, b);
+        ++b;
+      }
+      while(c >= b) {
+        final int h = list[c].diff(v);
+        if(h < 0) break;
+        if(h == 0) s(c, d--);
+        --c;
+      }
+      if(b > c) break;
+      s(b++, c--);
+    }
+
+    final int n = s + e;
+    int k = Math.min(a - s, b - a);
+    s(s, b - k, k);
+    k = Math.min(d - c, n - d - 1);
+    s(b, n - k, k);
+
+    if((k = b - a) > 1) sort(s, k);
+    if((k = d - c) > 1) sort(n - k, k);
+  }
+
+  /**
+   * Swaps x[a .. (a+n-1)] with x[b .. (b+n-1)].
+   * @param a first offset
+   * @param b second offset
+   * @param n number of values
+   */
+  private void s(final int a, final int b, final int n) {
+    for(int i = 0; i < n; ++i) s(a + i, b + i);
+  }
+
+  /**
+   * Returns the index of the median of the three indexed integers.
+   * @param a first offset
+   * @param b second offset
+   * @param c thirst offset
+   * @return median
+   */
+  private int m(final int a, final int b, final int c) {
+    return list[a].diff(list[b]) < 0 ?
+      list[b].diff(list[c]) < 0 ? b : list[a].diff(list[c]) < 0 ? c : a :
+      list[b].diff(list[c]) > 0 ? b : list[a].diff(list[c]) > 0 ? c : a;
+  }
+
+  /**
+   * Swaps two entries.
+   * @param a first position
+   * @param b second position
+   */
+  private void s(final int a, final int b) {
+    final ANode tmp = list[a];
+    list[a] = list[b];
+    list[b] = tmp;
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/list/ExprList.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/list/ExprList.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/list/ExprList.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/list/ExprList.java	2015-07-14 10:54:40.000000000 +0000
@@ -4,7 +4,7 @@
 import org.basex.util.list.*;
 
 /**
- * This is a simple container for expressions.
+ * Resizable-array implementation for XQuery expressions.
  *
  * @author BaseX Team 2005-15, BSD License
  * @author Christian Gruen
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/list/ItemList.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/list/ItemList.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/list/ItemList.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/list/ItemList.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,185 @@
+package org.basex.query.util.list;
+
+import java.util.*;
+
+import org.basex.query.iter.*;
+import org.basex.query.value.*;
+import org.basex.query.value.item.*;
+import org.basex.query.value.type.*;
+import org.basex.util.*;
+import org.basex.util.list.*;
+
+/**
+ * Resizable-array implementation for items.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Leo Woerteler
+ */
+public final class ItemList extends ElementList implements Iterable<Item> {
+  /** Element container. */
+  private Item[] list;
+
+  /**
+   * Default constructor.
+   */
+  public ItemList() {
+    this(1);
+  }
+
+  /**
+   * Constructor, specifying an initial array capacity.
+   * @param capacity array capacity
+   */
+  public ItemList(final int capacity) {
+    list = new Item[capacity];
+  }
+
+  /**
+   * Constructor, specifying an initial entry.
+   * @param element array capacity
+   */
+  public ItemList(final Item element) {
+    list = new Item[] { element };
+    size = 1;
+  }
+
+  /**
+   * Returns the specified element.
+   * @param p position
+   * @return value
+   */
+  public Item get(final int p) {
+    return list[p];
+  }
+
+  /**
+   * Adds an element to the array.
+   * @param element element to be added
+   * @return self reference
+   */
+  public ItemList add(final Item element) {
+    if(size == list.length) resize(newSize());
+    list[size++] = element;
+    return this;
+  }
+
+  /**
+   * Adds all elements in the given value to this list.
+   * @param value value to add
+   * @return self reference
+   */
+  public ItemList add(final Value value) {
+    if(value instanceof Item) return add((Item) value);
+    final long n = value.size();
+    if(n > Integer.MAX_VALUE - size) throw Util.notExpected(n);
+    final int newSize = size + (int) n;
+    int sz = size;
+    if(newSize > sz) {
+      do {
+        sz = Array.newSize(sz, factor);
+      } while(sz < newSize);
+      resize(sz);
+    }
+    size += value.writeTo(list, size);
+    return this;
+  }
+
+  /**
+   * Resizes the array.
+   * @param sz new size
+   */
+  private void resize(final int sz) {
+    final Item[] tmp = new Item[sz];
+    System.arraycopy(list, 0, tmp, 0, size);
+    list = tmp;
+  }
+
+  /**
+   * Returns an array with all elements and invalidates the internal array.
+   * Warning: the function must only be called if the list is discarded afterwards.
+   * @return array (internal representation!)
+   */
+  public Item[] finish() {
+    Item[] lst = list;
+    final int s = size;
+    if(s != lst.length) {
+      lst = new Item[s];
+      System.arraycopy(list, 0, lst, 0, s);
+    }
+    list = null;
+    return lst;
+  }
+
+  /**
+   * Returns a value containing the items in this list.
+   * @return the value
+   */
+  public Value value() {
+    return value(null);
+  }
+
+  /**
+   * Returns a value with the given element type containing the items in this list.
+   * @param type item type (not checked), may be {@code null}
+   * @return the value
+   */
+  public Value value(final Type type) {
+    return ValueBuilder.value(list, size, type);
+  }
+
+  /**
+   * Sets the item at the given position to the given value.
+   * @param pos position
+   * @param item new value
+   * @return self reference
+   */
+  public ItemList set(final int pos, final Item item) {
+    if(pos >= size) resize(newSize(pos + 1));
+    list[pos] = item;
+    return this;
+  }
+
+  /**
+   * Returns an iterator over the items in this list.
+   * The list must not be modified after the iterator has been requested.
+   * @return the iterator
+   */
+  public Iter iter() {
+    return new Iter() {
+      int pos;
+
+      @Override
+      public Value value() {
+        return ItemList.this.value();
+      }
+
+      @Override
+      public long size() {
+        return size;
+      }
+
+      @Override
+      public Item next() {
+        return pos < size ? list[pos++] : null;
+      }
+
+      @Override
+      public Item get(final long i) {
+        return list[(int) i];
+      }
+    };
+  }
+
+  /**
+   * Returns the current backing array of this list.
+   * @return the backing array
+   */
+  public Item[] internal() {
+    return list;
+  }
+
+  @Override
+  public Iterator<Item> iterator() {
+    return new ArrayIterator<>(list, size);
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/list/ValueList.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/list/ValueList.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/list/ValueList.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/list/ValueList.java	2015-07-14 10:54:40.000000000 +0000
@@ -5,7 +5,7 @@
 import org.basex.util.list.*;
 
 /**
- * This is a simple container for values.
+ * Resizable-array implementation for values.
  *
  * @author BaseX Team 2005-15, BSD License
  * @author Christian Gruen
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/pkg/ModuleLoader.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/pkg/ModuleLoader.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/pkg/ModuleLoader.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/pkg/ModuleLoader.java	2015-07-14 10:54:40.000000000 +0000
@@ -253,8 +253,15 @@
     final Package pkg = new PkgParser(ii).parse(pkgDesc);
     // check if package contains a jar descriptor
     final IOFile jarDesc = new IOFile(pkgDir, PkgText.JARDESC);
+    // choose module directory (support for both 2010 and 2012 specs)
+    IOFile modDir = new IOFile(pkgDir, PkgText.CONTENT);
+    if(!modDir.exists()) modDir = new IOFile(pkgDir, string(pkg.abbrev));
+
     // add jars to classpath
-    if(jarDesc.exists()) addJar(jarDesc, pkgDir, string(pkg.abbrev), ii);
+    if(jarDesc.exists()) {
+      final JarDesc desc = new JarParser(ii).parse(jarDesc);
+      for(final byte[] u : desc.jars) addURL(new IOFile(modDir, string(u)));
+    }
 
     // package has dependencies -> they have to be loaded first => put package
     // in list with packages to be loaded
@@ -269,7 +276,7 @@
       }
     }
     for(final Component comp : pkg.comps) {
-      final String p = new IOFile(new IOFile(pkgDir, string(pkg.abbrev)), string(comp.file)).path();
+      final String p = new IOFile(modDir, string(comp.file)).path();
       qp.module(token(p), comp.uri);
     }
     if(toLoad.contains(name)) toLoad.delete(name);
@@ -277,22 +284,6 @@
   }
 
   /**
-   * Adds the jar files registered in jarDesc.
-   * @param jarDesc jar descriptor
-   * @param pkgDir package directory
-   * @param modDir module directory
-   * @param ii input info
-   * @throws QueryException query exception
-   */
-  private void addJar(final IOFile jarDesc, final IOFile pkgDir, final String modDir,
-      final InputInfo ii) throws QueryException {
-
-    // add new URLs
-    final JarDesc desc = new JarParser(ii).parse(jarDesc);
-    for(final byte[] u : desc.jars) addURL(new IOFile(new IOFile(pkgDir, modDir), string(u)));
-  }
-
-  /**
    * Adds a URL to the cache.
    * @param jar jar file to be added
    */
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/pkg/PkgParser.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/pkg/PkgParser.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/pkg/PkgParser.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/pkg/PkgParser.java	2015-07-14 10:54:40.000000000 +0000
@@ -66,7 +66,7 @@
   private void parseAttributes(final ANode node, final Package p, final byte[] root)
       throws QueryException {
 
-    final AxisIter atts = node.attributes();
+    final BasicNodeIter atts = node.attributes();
     for(ANode next; (next = atts.next()) != null;) {
       final byte[] name = next.name();
       if(eq(A_NAME, name))         p.name = next.string();
@@ -94,7 +94,7 @@
    * @throws QueryException query exception
    */
   private void parseChildren(final ANode node, final Package p) throws QueryException {
-    final AxisIter ch = childElements(node);
+    final BasicNodeIter ch = childElements(node);
     for(ANode next; (next = ch.next()) != null;) {
       final QNm name = next.qname();
       if(eqNS(DEPEND, name)) p.dep.add(parseDependency(next));
@@ -109,7 +109,7 @@
    * @throws QueryException query exception
    */
   private Dependency parseDependency(final ANode node) throws QueryException {
-    final AxisIter atts = node.attributes();
+    final BasicNodeIter atts = node.attributes();
     final Dependency d = new Dependency();
     for(ANode next; (next = atts.next()) != null;) {
       final byte[] name = next.name();
@@ -131,7 +131,7 @@
    * @throws QueryException query exception
    */
   private Component parseComp(final ANode node) throws QueryException {
-    final AxisIter ch = childElements(node);
+    final BasicNodeIter ch = childElements(node);
     final Component c = new Component();
     for(ANode next; (next = ch.next()) != null;) {
       final QNm name = next.qname();
@@ -152,10 +152,10 @@
    * @param node root node
    * @return child element iterator
    */
-  private static AxisIter childElements(final ANode node) {
-    return new AxisIter() {
+  private static BasicNodeIter childElements(final ANode node) {
+    return new BasicNodeIter() {
       /** Child iterator. */
-      final AxisIter ch = node.children();
+      final BasicNodeIter ch = node.children();
 
       @Override
       public ANode next() {
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/pkg/PkgText.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/pkg/PkgText.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/pkg/PkgText.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/pkg/PkgText.java	2015-07-14 10:54:40.000000000 +0000
@@ -24,6 +24,8 @@
   String EXPATH = "EXPath";
   /** Internal type. */
   String INTERNAL = "Internal";
+  /** Content directory. */
+  String CONTENT = "content";
 
   /** <package/> root element. */
   /** Element package. */
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/regex/parse/RegExParser.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/regex/parse/RegExParser.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/regex/parse/RegExParser.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/regex/parse/RegExParser.java	2015-07-14 10:54:40.000000000 +0000
@@ -7,8 +7,8 @@
 
 import org.basex.query.*;
 import org.basex.query.util.regex.*;
+import org.basex.query.util.*;
 import org.basex.util.*;
-
 import static org.basex.util.Token.*;
 import static java.util.regex.Pattern.*;
 
@@ -599,31 +599,31 @@
     throw new Error("Missing return statement in function");
   }
 
-  private boolean jj_2_1(final int xla) {
+  private boolean jj_2_1(int xla) {
     jj_la = xla; jj_lastpos = jj_scanpos = token;
     try { return !jj_3_1(); }
-    catch(final LookaheadSuccess ls) { return true; }
+    catch(LookaheadSuccess ls) { return true; }
     finally { jj_save(0, xla); }
   }
 
-  private boolean jj_2_2(final int xla) {
+  private boolean jj_2_2(int xla) {
     jj_la = xla; jj_lastpos = jj_scanpos = token;
     try { return !jj_3_2(); }
-    catch(final LookaheadSuccess ls) { return true; }
+    catch(LookaheadSuccess ls) { return true; }
     finally { jj_save(1, xla); }
   }
 
-  private boolean jj_2_3(final int xla) {
+  private boolean jj_2_3(int xla) {
     jj_la = xla; jj_lastpos = jj_scanpos = token;
     try { return !jj_3_3(); }
-    catch(final LookaheadSuccess ls) { return true; }
+    catch(LookaheadSuccess ls) { return true; }
     finally { jj_save(2, xla); }
   }
 
-  private boolean jj_2_4(final int xla) {
+  private boolean jj_2_4(int xla) {
     jj_la = xla; jj_lastpos = jj_scanpos = token;
     try { return !jj_3_4(); }
-    catch(final LookaheadSuccess ls) { return true; }
+    catch(LookaheadSuccess ls) { return true; }
     finally { jj_save(3, xla); }
   }
 
@@ -757,7 +757,7 @@
 
 
   /** Constructor with user supplied Token Manager. */
-  public RegExParser(final TokenManager tm) {
+  public RegExParser(TokenManager tm) {
     token_source = tm;
     token = new Token();
     jj_ntk = -1;
@@ -767,7 +767,7 @@
   }
 
   /** Reinitialise. */
-  public void ReInit(final TokenManager tm) {
+  public void ReInit(TokenManager tm) {
     token_source = tm;
     token = new Token();
     jj_ntk = -1;
@@ -776,7 +776,7 @@
     for (int i = 0; i < jj_2_rtns.length; i++) jj_2_rtns[i] = new JJCalls();
   }
 
-  private Token jj_consume_token(final int kind) throws ParseException {
+  private Token jj_consume_token(int kind) throws ParseException {
     Token oldToken;
     if ((oldToken = token).next != null) token = token.next;
     else token = token.next = token_source.getNextToken();
@@ -785,8 +785,8 @@
       jj_gen++;
       if (++jj_gc > 100) {
         jj_gc = 0;
-        for(final JJCalls jj_2_rtn : jj_2_rtns) {
-          JJCalls c = jj_2_rtn;
+        for (int i = 0; i < jj_2_rtns.length; i++) {
+          JJCalls c = jj_2_rtns[i];
           while (c != null) {
             if (c.gen < jj_gen) c.first = null;
             c = c.next;
@@ -802,7 +802,7 @@
 
   static private final class LookaheadSuccess extends java.lang.Error { }
   final private LookaheadSuccess jj_ls = new LookaheadSuccess();
-  private boolean jj_scan_token(final int kind) {
+  private boolean jj_scan_token(int kind) {
     if (jj_scanpos == jj_lastpos) {
       jj_la--;
       if (jj_scanpos.next == null) {
@@ -834,7 +834,7 @@
   }
 
 /** Get the specific Token. */
-  final public Token getToken(final int index) {
+  final public Token getToken(int index) {
     Token t = jj_lookingAhead ? jj_scanpos : token;
     for (int i = 0; i < index; i++) {
       if (t.next != null) t = t.next;
@@ -850,13 +850,13 @@
       return (jj_ntk = jj_nt.kind);
   }
 
-  private final java.util.List<int[]> jj_expentries = new java.util.ArrayList<int[]>();
+  private java.util.List<int[]> jj_expentries = new java.util.ArrayList<int[]>();
   private int[] jj_expentry;
   private int jj_kind = -1;
-  private final int[] jj_lasttokens = new int[100];
+  private int[] jj_lasttokens = new int[100];
   private int jj_endpos;
 
-  private void jj_add_error_token(final int kind, final int pos) {
+  private void jj_add_error_token(int kind, int pos) {
     if (pos >= 100) return;
     if (pos == jj_endpos + 1) {
       jj_lasttokens[jj_endpos++] = kind;
@@ -865,8 +865,8 @@
       for (int i = 0; i < jj_endpos; i++) {
         jj_expentry[i] = jj_lasttokens[i];
       }
-      jj_entries_loop: for(final Object name : jj_expentries) {
-        final int[] oldentry = (int[])(name);
+      jj_entries_loop: for (java.util.Iterator<?> it = jj_expentries.iterator(); it.hasNext();) {
+        int[] oldentry = (int[])(it.next());
         if (oldentry.length == jj_expentry.length) {
           for (int i = 0; i < jj_expentry.length; i++) {
             if (oldentry[i] != jj_expentry[i]) {
@@ -884,7 +884,7 @@
   /** Generate ParseException. */
   public ParseException generateParseException() {
     jj_expentries.clear();
-    final boolean[] la1tokens = new boolean[25];
+    boolean[] la1tokens = new boolean[25];
     if (jj_kind >= 0) {
       la1tokens[jj_kind] = true;
       jj_kind = -1;
@@ -908,7 +908,7 @@
     jj_endpos = 0;
     jj_rescan_token();
     jj_add_error_token(0, 0);
-    final int[][] exptokseq = new int[jj_expentries.size()][];
+    int[][] exptokseq = new int[jj_expentries.size()][];
     for (int i = 0; i < jj_expentries.size(); i++) {
       exptokseq[i] = jj_expentries.get(i);
     }
@@ -940,12 +940,12 @@
         }
         p = p.next;
       } while (p != null);
-      } catch(final LookaheadSuccess ls) { }
+      } catch(LookaheadSuccess ls) { }
     }
     jj_rescan = false;
   }
 
-  private void jj_save(final int index, final int xla) {
+  private void jj_save(int index, int xla) {
     JJCalls p = jj_2_rtns[index];
     while (p.gen > jj_gen) {
       if (p.next == null) { p = p.next = new JJCalls(); break; }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/regex/RegExpList.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/regex/RegExpList.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/regex/RegExpList.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/regex/RegExpList.java	2015-07-14 10:54:40.000000000 +0000
@@ -3,7 +3,7 @@
 import org.basex.util.list.*;
 
 /**
- * This is a simple container for expressions.
+ * Resizable-array implementation for regular expressions.
  *
  * @author BaseX Team 2005-15, BSD License
  * @author Christian Gruen
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/util/UriResolver.java basex-8.2.3/basex-core/src/main/java/org/basex/query/util/UriResolver.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/util/UriResolver.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/util/UriResolver.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,18 @@
+package org.basex.query.util;
+
+import org.basex.io.*;
+import org.basex.query.value.item.*;
+
+/**
+ * Interface for resolving URIs in query modules.
+ */
+public interface UriResolver {
+  /**
+   * Locates a file, given the optional namespace URI and a path to the location.
+   * @param path path (relative or absolute)
+   * @param uri uri (can be {@code null})
+   * @param base base uri (can be {@code null})
+   * @return reference to resources
+   */
+  IO resolve(String path, String uri, Uri base);
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/array/ArrayBuilder.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/array/ArrayBuilder.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/array/ArrayBuilder.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/array/ArrayBuilder.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,7 +1,5 @@
 package org.basex.query.value.array;
 
-import java.util.*;
-
 import org.basex.query.util.fingertree.*;
 import org.basex.query.value.*;
 
@@ -109,8 +107,7 @@
    */
   public ArrayBuilder append(final Array arr) {
     if(!(arr instanceof BigArray)) {
-      final Iterator<Value> members = arr.members();
-      while(members.hasNext()) append(members.next());
+      for(final Value val : arr.members()) append(val);
       return this;
     }
 
@@ -195,18 +192,13 @@
         sb.append(vals[first]);
         for(int i = 1; i < n; i++) sb.append(", ").append(vals[(first + i) % CAP]);
       }
-      return sb.append(']').toString();
-    }
-
-    if(inLeft > 0) {
+    } else {
       final int first = (mid - inLeft + CAP) % CAP;
       sb.append(vals[first]);
       for(int i = 1; i < inLeft; i++) sb.append(", ").append(vals[(first + i) % CAP]);
-      sb.append(", ");
+      for(final Value val : tree) sb.append(", ").append(val);
+      for(int i = 0; i < inRight; i++) sb.append(", ").append(vals[(mid + i) % CAP]);
     }
-
-    tree.toString(sb);
-    for(int i = 0; i < inRight; i++) sb.append(", ").append(vals[(mid + i) % CAP]);
     return sb.append(']').toString();
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/array/Array.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/array/Array.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/array/Array.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/array/Array.java	2015-07-14 10:54:40.000000000 +0000
@@ -8,7 +8,6 @@
 import org.basex.query.*;
 import org.basex.query.expr.*;
 import org.basex.query.func.fn.*;
-import org.basex.query.iter.*;
 import org.basex.query.util.collation.*;
 import org.basex.query.util.list.*;
 import org.basex.query.value.*;
@@ -64,35 +63,13 @@
 
   /**
    * Creates an array containing the given elements.
-   * @param elems elements
+   * @param values elements
    * @return the resulting array
    */
   @SafeVarargs
-  public static Array from(final Value... elems) {
+  public static Array from(final Value... values) {
     final ArrayBuilder builder = new ArrayBuilder();
-    for(final Value val : elems) builder.append(val);
-    return builder.freeze();
-  }
-
-  /**
-   * Creates an array containing the elements from the given {@link Iterable}.
-   * @param iter the iterable
-   * @return the resulting array
-   */
-  public static Array from(final Iterable<Value> iter) {
-    final ArrayBuilder builder = new ArrayBuilder();
-    for(final Value val : iter) builder.append(val);
-    return builder.freeze();
-  }
-
-  /**
-   * Creates an array containing the elements from the given {@link Iterator}.
-   * @param iter the iterator
-   * @return the resulting array
-   */
-  public static Array from(final Iterator<Value> iter) {
-    final ArrayBuilder builder = new ArrayBuilder();
-    while(iter.hasNext()) builder.append(iter.next());
+    for(final Value val : values) builder.append(val);
     return builder.freeze();
   }
 
@@ -183,7 +160,7 @@
    * Running time: <i>O(n)</i>
    * @return reversed version of this array
    */
-  public abstract Array reverse();
+  public abstract Array reverseArray();
 
   @Override
   public final boolean isEmpty() {
@@ -218,17 +195,29 @@
 
   /**
    * Iterator over the members of this array.
-   * @param reverse flag for iterating from back to front
+   * @param start starting position
+   *   (i.e. the position initially returned by {@link ListIterator#nextIndex()})
    * @return array over the array members
    */
-  public abstract ListIterator<Value> members(final boolean reverse);
+  public abstract ListIterator<Value> iterator(final long start);
+
+  /** Iterable over the elements of this array. */
+  private Iterable<Value> iterable;
 
   /**
    * Iterator over the members of this array.
    * @return array over the array members
    */
-  public final ListIterator<Value> members() {
-    return members(false);
+  public final Iterable<Value> members() {
+    if(iterable == null) {
+      iterable = new Iterable<Value>() {
+        @Override
+        public Iterator<Value> iterator() {
+          return Array.this.iterator(0);
+        }
+      };
+    }
+    return iterable;
   }
 
   /**
@@ -277,12 +266,6 @@
    */
   abstract void checkInvariants();
 
-  /**
-   * Returns an array containing the number of elements stored at each level of the tree.
-   * @return array of sizes
-   */
-  abstract long[] sizes();
-
   @Override
   public Value invValue(final QueryContext qc, final InputInfo ii, final Value... args)
       throws QueryException {
@@ -347,8 +330,7 @@
   @Override
   public Array materialize(final InputInfo ii) throws QueryException {
     final ArrayBuilder builder = new ArrayBuilder();
-    final Iterator<Value> iter = members();
-    while(iter.hasNext()) builder.append(iter.next().materialize(ii));
+    for(final Value val : members()) builder.append(val.materialize(ii));
     return builder.freeze();
   }
 
@@ -366,11 +348,8 @@
   @Override
   public long atomSize() {
     long s = 0;
-    final Iterator<Value> iter = members();
-    while(iter.hasNext()) {
-      final Value v = iter.next();
-      final long vs = v.size();
-      for(int i = 0; i < vs; i++) s += v.itemAt(i).atomSize();
+    for(final Value val : members()) {
+      for(final Item it : val) s += it.atomSize();
     }
     return s;
   }
@@ -386,8 +365,8 @@
     final long s = atomSize(), size = arraySize();
     if(single && s > 1) throw SEQFOUND_X.get(ii, this);
     if(size == 1) return get(0).atomValue(ii);
-    final ValueBuilder vb = new ValueBuilder((int) s);
-    for(long a = 0; a < size; a++) vb.add(get(a).atomValue(ii));
+    final ValueBuilder vb = new ValueBuilder();
+    for(final Value val : members()) vb.add(val.atomValue(ii));
     return vb.value();
   }
 
@@ -412,16 +391,14 @@
   public void string(final TokenBuilder tb, final InputInfo ii) throws QueryException {
     tb.add('[');
     int c = 0;
-    final Iterator<Value> iter = members();
-    while(iter.hasNext()) {
+    for(final Value val : members()) {
       if(c++ > 0) tb.add(", ");
-      final Value v = iter.next();
-      final long vs = v.size();
+      final long vs = val.size();
       if(vs != 1) tb.add('(');
       int cc = 0;
       for(int i = 0; i < vs; i++) {
         if(cc++ > 0) tb.add(", ");
-        final Item it = v.itemAt(i);
+        final Item it = val.itemAt(i);
         if(it instanceof Array) ((Array) it).string(tb, ii);
         else if(it instanceof Map) ((Map) it).string(tb, 0, ii);
         else tb.add(it.toString());
@@ -438,8 +415,7 @@
    */
   public boolean hasType(final ArrayType t) {
     if(!t.retType.eq(SeqType.ITEM_ZM)) {
-      final Iterator<Value> iter = members();
-      while(iter.hasNext()) if(!t.retType.instance(iter.next())) return false;
+      for(final Value val : members()) if(!t.retType.instance(val)) return false;
     }
     return true;
   }
@@ -458,7 +434,7 @@
     if(item instanceof Array) {
       final Array o = (Array) item;
       if(arraySize() != o.arraySize()) return false;
-      final Iterator<Value> it1 = members(), it2 = o.members();
+      final Iterator<Value> it1 = iterator(0), it2 = o.iterator(0);
       while(it1.hasNext()) {
         final Value v1 = it1.next(), v2 = it2.next();
         if(v1.size() != v2.size() || !new Compare(ii).collation(coll).equal(v1, v2))
@@ -487,7 +463,7 @@
   public Object[] toJava() throws QueryException {
     final long size = arraySize();
     final Object[] tmp = new Object[(int) size];
-    final Iterator<Value> iter = members();
+    final Iterator<Value> iter = iterator(0);
     for(int i = 0; iter.hasNext(); i++) tmp[i] = iter.next().toJava();
     return tmp;
   }
@@ -495,7 +471,7 @@
   @Override
   public String toString() {
     final StringBuilder tb = new StringBuilder().append('[');
-    final Iterator<Value> iter = members();
+    final Iterator<Value> iter = iterator(0);
     for(boolean fst = true; iter.hasNext(); fst = false) {
       if(!fst) tb.append(", ");
       final Value value = iter.next();
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/array/BigArray.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/array/BigArray.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/array/BigArray.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/array/BigArray.java	2015-07-14 10:54:40.000000000 +0000
@@ -199,7 +199,7 @@
       midNodes[i] = new LeafNode(arr);
     }
 
-    return new BigArray(left, middle.concat(midNodes, other.middle), other.right);
+    return new BigArray(left, middle.concat(midNodes, n, other.middle), other.right);
   }
 
   @Override
@@ -220,7 +220,7 @@
   }
 
   @Override
-  public Array reverse() {
+  public Array reverseArray() {
     final int l = left.length, r = right.length;
     final Value[] newLeft = new Value[r], newRight = new Value[l];
     for(int i = 0; i < r; i++) newLeft[i] = right[r - 1 - i];
@@ -534,17 +534,29 @@
   }
 
   @Override
-  public ListIterator<Value> members(final boolean reverse) {
+  public ListIterator<Value> iterator(final long start) {
     final Value[] ls = left, rs = right;
-    final int l = ls.length, m = (int) middle.size(), r = rs.length;
-    final ListIterator<Value> sub = middle.listIterator(reverse);
+    final int l = ls.length , r = rs.length, startPos;
+    final long m = middle.size();
+    final ListIterator<Value> sub;
+    if(start < l) {
+      startPos = (int) start - l;
+      sub = middle.listIterator(0);
+    } else if(start - l < m) {
+      startPos = 0;
+      sub = middle.listIterator(start - l);
+    } else {
+      startPos = (int) (start - l - m) + 1;
+      sub = middle.listIterator(m);
+    }
+
     return new ListIterator<Value>() {
-      int pos = reverse ? r + 1 : -l;
+      int pos = startPos;
 
       @Override
       public int nextIndex() {
         return pos < 0 ? l + pos
-             : pos > 0 ? l + m + pos - 1
+             : pos > 0 ? (int) (l + m + pos - 1)
                        : l + sub.nextIndex();
       }
 
@@ -574,7 +586,7 @@
       @Override
       public int previousIndex() {
         return pos < 0 ? l + pos - 1
-             : pos > 0 ? l + m + pos - 2
+             : pos > 0 ? (int) (l + m + pos - 2)
                        : l + sub.previousIndex();
       }
 
@@ -628,13 +640,6 @@
   }
 
   @Override
-  long[] sizes() {
-    final long[] sizes = middle.sizes(1);
-    sizes[0] = left.length + right.length;
-    return sizes;
-  }
-
-  @Override
   Array consSmall(final Value[] vals) {
     final int a = vals.length, b = left.length, n = a + b;
     if(n <= MAX_DIGIT) {
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/array/EmptyArray.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/array/EmptyArray.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/array/EmptyArray.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/array/EmptyArray.java	2015-07-14 10:54:40.000000000 +0000
@@ -78,7 +78,7 @@
   }
 
   @Override
-  public Array reverse() {
+  public Array reverseArray() {
     return this;
   }
 
@@ -96,7 +96,7 @@
   }
 
   @Override
-  public ListIterator<Value> members(final boolean reverse) {
+  public ListIterator<Value> iterator(final long size) {
     return Collections.emptyListIterator();
   }
 
@@ -106,11 +106,6 @@
   }
 
   @Override
-  long[] sizes() {
-    return new long[] { 0 };
-  }
-
-  @Override
   Array consSmall(final Value[] vals) {
     return new SmallArray(vals);
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/array/LeafNode.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/array/LeafNode.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/array/LeafNode.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/array/LeafNode.java	2015-07-14 10:54:40.000000000 +0000
@@ -11,7 +11,7 @@
  * @author BaseX Team 2005-15, BSD License
  * @author Leo Woerteler
  */
-final class LeafNode extends Node<Value, Value> {
+final class LeafNode implements Node<Value, Value> {
   /** Elements stored in this leaf node. */
   final Value[] values;
 
@@ -25,12 +25,12 @@
   }
 
   @Override
-  protected long size() {
+  public long size() {
     return values.length;
   }
 
   @Override
-  protected LeafNode reverse() {
+  public LeafNode reverse() {
     final int n = values.length;
     final Value[] out = new Value[n];
     for(int i = 0; i < n; i++) out[i] = values[n - 1 - i];
@@ -38,7 +38,7 @@
   }
 
   @Override
-  protected boolean insert(final Node<Value, Value>[] siblings,
+  public boolean insert(final Node<Value, Value>[] siblings,
       final long pos, final Value val) {
     final int p = (int) pos, n = values.length;
     final Value[] vals = new Value[n + 1];
@@ -93,20 +93,11 @@
   }
 
   @Override
-  protected NodeLike<Value, Value> remove(final long pos) {
-    final int p = (int) pos, n = values.length;
-    final Value[] out = new Value[n - 1];
-    System.arraycopy(values, 0, out, 0, p);
-    System.arraycopy(values, p + 1, out, p, n - 1 - p);
-    return n == Array.MIN_LEAF ? new PartialLeafNode(out) : new LeafNode(out);
-  }
-
-  @Override
-  protected Node<Value, Value>[] remove(final Node<Value, Value> left,
+  public NodeLike<Value, Value>[] remove(final Node<Value, Value> left,
       final Node<Value, Value> right, final long pos) {
     final int p = (int) pos, n = values.length;
     @SuppressWarnings("unchecked")
-    final Node<Value, Value>[] out = new Node[] { left, null, right };
+    final NodeLike<Value, Value>[] out = new NodeLike[] { left, null, right };
     if(n > Array.MIN_LEAF) {
       // we do not have to split
       final Value[] vals = new Value[n - 1];
@@ -160,7 +151,10 @@
       System.arraycopy(values, p + 1, vals, l + p, r - 1 - p);
       out[0] = new LeafNode(vals);
       out[1] = null;
-    } else {
+      return out;
+    }
+
+    if(right != null) {
       // merge with right neighbor
       final Value[] rvals = ((LeafNode) right).values;
       final int l = values.length, r = rvals.length;
@@ -170,44 +164,19 @@
       System.arraycopy(rvals, 0, vals, l - 1, r);
       out[1] = null;
       out[2] = new LeafNode(vals);
+      return out;
     }
 
+    // underflow
+    final Value[] vals = new Value[n - 1];
+    System.arraycopy(values, 0, vals, 0, p);
+    System.arraycopy(values, p + 1, vals, p, n - 1 - p);
+    out[1] = new PartialLeafNode(vals);
     return out;
   }
 
   @Override
-  protected NodeLike<Value, Value>[] concat(final NodeLike<Value, Value> other) {
-    @SuppressWarnings("unchecked")
-    final NodeLike<Value, Value>[] arr = new NodeLike[2];
-
-    if(other instanceof PartialLeafNode) {
-      final Value[] left = values, right = ((PartialLeafNode) other).elems;
-      final int l = left.length, r = right.length, n = l + r;
-      if(n <= Array.MAX_LEAF) {
-        // merge into one node
-        final Value[] vals = new Value[n];
-        System.arraycopy(left, 0, vals, 0, l);
-        System.arraycopy(right, 0, vals, l, r);
-        arr[0] = new LeafNode(vals);
-      } else {
-        // split into two
-        final int ll = n / 2, rl = n - ll, move = l - ll;
-        final Value[] newLeft = new Value[ll], newRight = new Value[rl];
-        System.arraycopy(left, 0, newLeft, 0, ll);
-        System.arraycopy(left, ll, newRight, 0, move);
-        System.arraycopy(right, 0, newRight, move, r);
-        arr[0] = new LeafNode(newLeft);
-        arr[1] = new LeafNode(newRight);
-      }
-    } else {
-      arr[0] = this;
-      arr[1] = other;
-    }
-    return arr;
-  }
-
-  @Override
-  protected int append(final NodeLike<Value, Value>[] nodes, final int pos) {
+  public int append(final NodeLike<Value, Value>[] nodes, final int pos) {
     if(pos == 0) {
       nodes[pos] = this;
       return 1;
@@ -242,7 +211,7 @@
   }
 
   @Override
-  protected NodeLike<Value, Value> slice(final long off, final long size) {
+  public NodeLike<Value, Value> slice(final long off, final long size) {
     final int p = (int) off, n = (int) size;
     final Value[] out = new Value[n];
     System.arraycopy(values, p, out, 0, n);
@@ -250,41 +219,24 @@
   }
 
   @Override
-  protected Node<Value, Value> replaceFirst(final Value newFirst) {
-    if(newFirst == values[0]) return this;
-    final Value[] vals = values.clone();
-    vals[0] = newFirst;
-    return new LeafNode(vals);
-  }
-
-  @Override
-  protected Node<Value, Value> replaceLast(final Value newLast) {
-    if(newLast == values[values.length - 1]) return this;
-    final Value[] vals = values.clone();
-    vals[vals.length - 1] = newLast;
-    return new LeafNode(vals);
-  }
-
-  @Override
-  protected void toString(final StringBuilder sb, final int indent) {
-    for(int i = 0; i < indent; i++) sb.append("  ");
-    sb.append("Node(").append(size()).append(")").append(Arrays.toString(values));
-  }
-
-  @Override
-  protected long checkInvariants() {
+  public long checkInvariants() {
     if(values.length < Array.MIN_LEAF || values.length > Array.MAX_LEAF)
       throw new AssertionError("Wrong " + getClass().getSimpleName() + " size: " + values.length);
     return values.length;
   }
 
   @Override
-  protected int arity() {
+  public int arity() {
     return values.length;
   }
 
   @Override
-  protected Value getSub(final int index) {
+  public Value getSub(final int index) {
     return values[index];
   }
+
+  @Override
+  public String toString() {
+    return getClass().getSimpleName() + "(" + size() + ")" + Arrays.toString(values);
+  }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/array/PartialLeafNode.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/array/PartialLeafNode.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/array/PartialLeafNode.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/array/PartialLeafNode.java	2015-07-14 10:54:40.000000000 +0000
@@ -11,7 +11,7 @@
  * @author BaseX Team 2005-15, BSD License
  * @author Leo Woerteler
  */
-final class PartialLeafNode extends PartialNode<Value, Value> {
+final class PartialLeafNode implements NodeLike<Value, Value> {
   /** The single element. */
   final Value[] elems;
 
@@ -24,41 +24,7 @@
   }
 
   @Override
-  protected NodeLike<Value, Value>[] concat(final NodeLike<Value, Value> other) {
-    @SuppressWarnings("unchecked")
-    final NodeLike<Value, Value>[] out = new NodeLike[2];
-    if(other instanceof LeafNode) {
-      final Value[] ls = elems, rs = ((LeafNode) other).values;
-      final int l = ls.length, r = rs.length, n = l + r;
-      if(n <= Array.MAX_LEAF) {
-        // merge into one node
-        final Value[] vals = new Value[n];
-        System.arraycopy(ls, 0, vals, 0, l);
-        System.arraycopy(rs, 0, vals, l, r);
-        out[0] = new LeafNode(vals);
-      } else {
-        // split into two
-        final int ll = n / 2, rl = n - ll, move = r - rl;
-        final Value[] newLeft = new Value[ll], newRight = new Value[rl];
-        System.arraycopy(ls, 0, newLeft, 0, l);
-        System.arraycopy(rs, 0, newLeft, l, move);
-        System.arraycopy(rs, move, newRight, 0, rl);
-        out[0] = new LeafNode(newLeft);
-        out[1] = new LeafNode(newRight);
-      }
-    } else {
-      final Value[] elems2 = ((PartialLeafNode) other).elems;
-      final int l = elems.length, r = elems2.length, n = l + r;
-      final Value[] vals = new Value[n];
-      System.arraycopy(elems, 0, vals, 0, l);
-      System.arraycopy(elems2, 0, vals, l, r);
-      out[0] = n < Array.MIN_LEAF ? new PartialLeafNode(vals) : new LeafNode(vals);
-    }
-    return out;
-  }
-
-  @Override
-  protected int append(final NodeLike<Value, Value>[] nodes, final int pos) {
+  public int append(final NodeLike<Value, Value>[] nodes, final int pos) {
     if(pos == 0) {
       nodes[0] = this;
       return 1;
@@ -96,8 +62,7 @@
   }
 
   @Override
-  protected void toString(final StringBuilder sb, final int indent) {
-    for(int i = 0; i < indent; i++) sb.append("  ");
-    sb.append(getClass().getSimpleName()).append(Arrays.toString(elems));
+  public String toString() {
+    return getClass().getSimpleName() + "(" + elems.length + ")" + Arrays.toString(elems);
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/array/SmallArray.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/array/SmallArray.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/array/SmallArray.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/array/SmallArray.java	2015-07-14 10:54:40.000000000 +0000
@@ -100,7 +100,7 @@
   }
 
   @Override
-  public Array reverse() {
+  public Array reverseArray() {
     final int n = elems.length;
     if(n == 1) return this;
     final Value[] es = new Value[n];
@@ -149,9 +149,9 @@
   }
 
   @Override
-  public ListIterator<Value> members(final boolean reverse) {
+  public ListIterator<Value> iterator(final long start) {
     return new ListIterator<Value>() {
-      private int index = reverse ? elems.length : 0;
+      private int index = (int) Math.max(0, Math.min(start, elems.length));
 
       @Override
       public int nextIndex() {
@@ -210,11 +210,6 @@
   }
 
   @Override
-  long[] sizes() {
-    return new long[] { elems.length };
-  }
-
-  @Override
   Array consSmall(final Value[] left) {
     final int l = left.length, r = elems.length, n = l + r;
     if(Math.min(l, r) >= MIN_DIGIT) {
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/item/Dtm.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/item/Dtm.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/item/Dtm.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/item/Dtm.java	2015-07-14 10:54:40.000000000 +0000
@@ -72,7 +72,7 @@
    * @throws QueryException query exception
    */
   public Dtm(final long ms, final InputInfo ii) throws QueryException {
-    this(Token.token(DateTime.format(new Date(ms), DateTime.FULL)), ii);
+    this(Token.token(DateTime.format(new Date(ms))), ii);
   }
 
   /**
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/item/FuncItem.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/item/FuncItem.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/item/FuncItem.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/item/FuncItem.java	2015-07-14 10:54:40.000000000 +0000
@@ -157,7 +157,7 @@
   public FItem coerceTo(final FuncType ft, final QueryContext qc, final InputInfo ii,
       final boolean opt) throws QueryException {
 
-    if(params.length != ft.argTypes.length) throw castError(ii, this, ft);
+    if(params.length != ft.argTypes.length) throw INVPROMOTE_X_X_X.get(ii, seqType(), ft, this);
     final FuncType tp = funcType();
     if(tp.instanceOf(ft)) return this;
 
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/item/Item.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/item/Item.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/item/Item.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/item/Item.java	2015-07-14 10:54:40.000000000 +0000
@@ -11,6 +11,7 @@
 import org.basex.query.util.collation.*;
 import org.basex.query.value.*;
 import org.basex.query.value.node.*;
+import org.basex.query.value.seq.*;
 import org.basex.query.value.type.*;
 import org.basex.query.value.type.Type.ID;
 import org.basex.util.*;
@@ -61,6 +62,11 @@
   }
 
   @Override
+  public final Item reverse() {
+    return this;
+  }
+
+  @Override
   public final Item ebv(final QueryContext qc, final InputInfo ii) {
     return this;
   }
@@ -189,6 +195,11 @@
     return new ArrayInput(string(ii));
   }
 
+  @Override
+  public Value subSeq(final long start, final long len) {
+    return len == 0 ? Empty.SEQ : this;
+  }
+
   // Overridden by B64Stream, StrStream, Jav and Array.
   @Override
   public Item materialize(final InputInfo ii) throws QueryException {
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/item/QNm.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/item/QNm.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/item/QNm.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/item/QNm.java	2015-07-14 10:54:40.000000000 +0000
@@ -24,6 +24,8 @@
 public final class QNm extends Item {
   /** URL pattern (matching Clark and EQName notation). */
   private static final Pattern BIND = Pattern.compile("^((\"|')(.*?)\\2:|Q?(\\{(.*?)\\}))(.+)$");
+  /** Expanded QName pattern. */
+  private static final Pattern EQNAME = Pattern.compile("(Q\\{([^}]*)\\})?([^}]+)");
   /** Singleton instance. */
   private static final QNmMap CACHE = new QNmMap();
 
@@ -112,7 +114,7 @@
    * Resolves a QName string.
    * @param name name to resolve
    * @param def default namespace (can be {@code null})
-   * @param sc static context
+   * @param sc static context (can be {@code null})
    * @param info input info
    * @return string
    * @throws QueryException query exception
@@ -122,7 +124,7 @@
 
     // check for namespace declaration
     final Matcher m = BIND.matcher(Token.string(name));
-    final byte[] uri;
+    byte[] uri = null;
     byte[] nm = name;
     if(m.find()) {
       final String u = m.group(3);
@@ -133,7 +135,7 @@
       if(i == -1) {
         uri = def;
       } else {
-        uri = sc.ns.uri(substring(nm, 0, i));
+        if(sc != null) uri = sc.ns.uri(substring(nm, 0, i));
         if(uri == null) throw NOURI_X.get(info, name);
       }
     }
@@ -142,6 +144,17 @@
   }
 
   /**
+   * Resolves an expanded QName string.
+   * @param name string
+   * @return resulting QName, or {@code null}
+   */
+  public static QNm resolve(final byte[] name) {
+    final Matcher m = EQNAME.matcher(Token.string(name));
+    return m.matches() ? new QNm(m.group(3), m.group(1) == null ||
+        m.group(2).isEmpty() ? null : m.group(2)) : null;
+  }
+
+  /**
    * Sets the URI of this QName.
    * @param u the uri to be set
    */
@@ -278,7 +291,7 @@
   public byte[] prefixId(final byte[] ns) {
     if(ns != null && Token.eq(uri(), ns)) return local();
     final byte[] p = NSGlobal.prefix(uri());
-    return p.length == 0 ? id() : concat(p, token(":"), local());
+    return p.length == 0 ? id() : Token.concat(p, token(":"), local());
   }
 
   @Override
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/map/Branch.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/map/Branch.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/map/Branch.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/map/Branch.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,7 +1,6 @@
 package org.basex.query.value.map;
 
 import org.basex.query.*;
-import org.basex.query.iter.*;
 import org.basex.query.util.collation.*;
 import org.basex.query.value.*;
 import org.basex.query.value.item.*;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/map/Leaf.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/map/Leaf.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/map/Leaf.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/map/Leaf.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,7 +1,6 @@
 package org.basex.query.value.map;
 
 import org.basex.query.*;
-import org.basex.query.iter.*;
 import org.basex.query.util.collation.*;
 import org.basex.query.value.*;
 import org.basex.query.value.item.*;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/map/List.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/map/List.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/map/List.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/map/List.java	2015-07-14 10:54:40.000000000 +0000
@@ -3,7 +3,6 @@
 import static org.basex.query.QueryText.*;
 
 import org.basex.query.*;
-import org.basex.query.iter.*;
 import org.basex.query.util.collation.*;
 import org.basex.query.value.*;
 import org.basex.query.value.item.*;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/map/Map.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/map/Map.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/map/Map.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/map/Map.java	2015-07-14 10:54:40.000000000 +0000
@@ -192,7 +192,7 @@
    */
   public Value keys() {
     if(keys == null) {
-      final ValueBuilder res = new ValueBuilder(root.size);
+      final ValueBuilder res = new ValueBuilder();
       root.keys(res);
       keys = res.value();
     }
@@ -203,10 +203,10 @@
    * All values defined in this map.
    * @return list of keys
    */
-  public ValueBuilder values() {
-    final ValueBuilder res = new ValueBuilder(root.size);
+  public Value values() {
+    final ValueBuilder res = new ValueBuilder();
     root.values(res);
-    return res;
+    return res.value();
   }
 
   /**
@@ -217,11 +217,11 @@
    * @return resulting value
    * @throws QueryException query exception
    */
-  public ValueBuilder apply(final FItem func, final QueryContext qc, final InputInfo ii)
+  public Value apply(final FItem func, final QueryContext qc, final InputInfo ii)
       throws QueryException {
-    final ValueBuilder vb = new ValueBuilder(root.size);
+    final ValueBuilder vb = new ValueBuilder();
     root.apply(vb, func, qc, ii);
-    return vb;
+    return vb.value();
   }
 
   @Override
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/map/TrieNode.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/map/TrieNode.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/map/TrieNode.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/map/TrieNode.java	2015-07-14 10:54:40.000000000 +0000
@@ -2,7 +2,6 @@
 
 import org.basex.query.*;
 import org.basex.query.func.fn.*;
-import org.basex.query.iter.*;
 import org.basex.query.util.collation.*;
 import org.basex.query.value.*;
 import org.basex.query.value.item.*;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/node/ANode.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/node/ANode.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/node/ANode.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/node/ANode.java	2015-07-14 10:54:40.000000000 +0000
@@ -160,11 +160,11 @@
     final Atts ns = new Atts();
     ANode node = this;
     do {
-      final Atts n = node.namespaces();
-      if(n != null) {
-        for(int a = n.size() - 1; a >= 0; a--) {
-          final byte[] key = n.name(a);
-          if(!ns.contains(key)) ns.add(key, n.value(a));
+      final Atts nsp = node.namespaces();
+      if(nsp != null) {
+        for(int a = nsp.size() - 1; a >= 0; a--) {
+          final byte[] key = nsp.name(a);
+          if(!ns.contains(key)) ns.add(key, nsp.value(a));
         }
       }
       node = node.parent();
@@ -236,7 +236,7 @@
         if(!nl.get(i).is(n)) continue;
         // check which node appears as first LCA child
         final ANode c1 = nl.get(i - 1);
-        final AxisMoreIter ir = n.children();
+        final BasicNodeIter ir = n.children();
         for(ANode c; (c = ir.next()) != null;) {
           if(c.is(c1)) return -1;
           if(c.is(c2)) return 1;
@@ -259,6 +259,15 @@
   }
 
   /**
+   * Returns the root of a node (the topmost ancestor without parent node).
+   * @return root node
+   */
+  public final ANode root() {
+    final ANode p = parent();
+    return p == null ? this : p.root();
+  }
+
+  /**
    * Returns the parent node.
    * @return parent node
    */
@@ -266,10 +275,10 @@
 
   /**
    * Sets the parent node.
-   * @param p parent node
+   * @param par parent node
    * @return self reference
    */
-  protected abstract ANode parent(final ANode p);
+  protected abstract ANode parent(final ANode par);
 
   /**
    * Returns true if the node has children.
@@ -301,9 +310,9 @@
    * @return attribute value
    */
   public byte[] attribute(final QNm name) {
-    final AxisIter ai = attributes();
+    final BasicNodeIter iter = attributes();
     while(true) {
-      final ANode node = ai.next();
+      final ANode node = iter.next();
       if(node == null) return null;
       if(node.qname().eq(name)) return node.string();
     }
@@ -311,118 +320,129 @@
 
   /**
    * Returns an ancestor axis iterator.
+   * If nodes returned are to be further used, they must be finalized via {@link ANode#finish()}.
    * @return iterator
    */
-  public abstract AxisIter ancestor();
+  public abstract BasicNodeIter ancestor();
 
   /**
    * Returns an ancestor-or-self axis iterator.
+   * If nodes returned are to be further used, they must be finalized via {@link ANode#finish()}.
    * @return iterator
    */
-  public abstract AxisIter ancestorOrSelf();
+  public abstract BasicNodeIter ancestorOrSelf();
 
   /**
    * Returns an attribute axis iterator.
+   * If nodes returned are to be further used, they must be finalized via {@link ANode#finish()}.
    * @return iterator
    */
-  public abstract AxisMoreIter attributes();
+  public abstract BasicNodeIter attributes();
 
   /**
    * Returns a child axis iterator.
+   * If nodes returned are to be further used, they must be finalized via {@link ANode#finish()}.
    * @return iterator
    */
-  public abstract AxisMoreIter children();
+  public abstract BasicNodeIter children();
 
   /**
    * Returns a descendant axis iterator.
+   * If nodes returned are to be further used, they must be finalized via {@link ANode#finish()}.
    * @return iterator
    */
-  public abstract AxisIter descendant();
+  public abstract BasicNodeIter descendant();
 
   /**
    * Returns a descendant-or-self axis iterator.
+   * If nodes returned are to be further used, they must be finalized via {@link ANode#finish()}.
    * @return iterator
    */
-  public abstract AxisIter descendantOrSelf();
+  public abstract BasicNodeIter descendantOrSelf();
 
   /**
    * Returns a following axis iterator.
+   * If nodes returned are to be further used, they must be finalized via {@link ANode#finish()}.
    * @return iterator
    */
-  public abstract AxisIter following();
+  public abstract BasicNodeIter following();
 
   /**
    * Returns a following-sibling axis iterator.
+   * If nodes returned are to be further used, they must be finalized via {@link ANode#finish()}.
    * @return iterator
    */
-  public abstract AxisIter followingSibling();
+  public abstract BasicNodeIter followingSibling();
 
   /**
    * Returns a parent axis iterator.
+   * If nodes returned are to be further used, they must be finalized via {@link ANode#finish()}.
    * @return iterator
    */
-  public abstract AxisIter parentIter();
+  public abstract BasicNodeIter parentIter();
 
   /**
    * Returns a preceding axis iterator.
+   * If nodes returned are to be further used, they must be finalized via {@link ANode#finish()}.
    * @return iterator
    */
-  public final AxisIter preceding() {
-    return new AxisIter() {
+  public final BasicNodeIter preceding() {
+    return new BasicNodeIter() {
       /** Iterator. */
-      private NodeSeqBuilder nc;
+      private BasicNodeIter iter;
 
       @Override
       public ANode next() {
-        if(nc == null) {
-          nc = new NodeSeqBuilder();
+        if(iter == null) {
+          final ANodeList list = new ANodeList();
           ANode n = ANode.this;
           ANode p = n.parent();
           while(p != null) {
             if(n.type != NodeType.ATT) {
-              final NodeSeqBuilder tmp = new NodeSeqBuilder();
-              final AxisIter ai = p.children();
-              for(ANode c; (c = ai.next()) != null && !c.is(n);) {
+              final ANodeList tmp = new ANodeList();
+              final BasicNodeIter ir = p.children();
+              for(ANode c; (c = ir.next()) != null && !c.is(n);) {
                 tmp.add(c.finish());
                 addDesc(c.children(), tmp);
               }
-              for(long t = tmp.size() - 1; t >= 0; t--) nc.add(tmp.get(t));
+              for(int t = tmp.size() - 1; t >= 0; t--) list.add(tmp.get(t));
             }
             n = p;
             p = p.parent();
           }
+          iter = list.iter();
         }
-        return nc.next();
+        return iter.next();
       }
     };
   }
 
   /**
    * Returns a preceding-sibling axis iterator.
+   * If nodes returned are to be further used, they must be finalized via {@link ANode#finish()}.
    * @return iterator
    */
-  public final AxisIter precedingSibling() {
-    return new AxisIter() {
+  public final BasicNodeIter precedingSibling() {
+    return new BasicNodeIter() {
       /** Child nodes. */
-      private NodeSeqBuilder nc;
+      private BasicNodeIter iter;
       /** Counter. */
-      private long c;
+      private int i;
 
       @Override
       public ANode next() {
-        if(nc == null) {
+        if(iter == null) {
           if(type == NodeType.ATT) return null;
           final ANode r = parent();
           if(r == null) return null;
 
-          nc = new NodeSeqBuilder();
-          final AxisIter ai = r.children();
-          for(ANode n; (n = ai.next()) != null && !n.is(ANode.this);) {
-            nc.add(n.finish());
-          }
-          c = nc.size();
+          final ANodeList list = new ANodeList();
+          final BasicNodeIter ir = r.children();
+          for(ANode n; (n = ir.next()) != null && !n.is(ANode.this);) list.add(n.finish());
+          i = list.size();
+          iter = list.iter();
         }
-        return c > 0 ? nc.get(--c) : null;
+        return i > 0 ? iter.get(--i) : null;
       }
     };
   }
@@ -431,18 +451,16 @@
    * Returns an self axis iterator.
    * @return iterator
    */
-  public final AxisMoreIter self() {
-    return new AxisMoreIter() {
-      /** First call. */
-      private boolean more = true;
+  public final BasicNodeIter self() {
+    return new BasicNodeIter() {
+      /** Flag. */
+      private boolean all;
 
       @Override
-      public boolean more() {
-        return more;
-      }
-      @Override
       public ANode next() {
-        return (more ^= true) ? null : ANode.this;
+        if(all) return null;
+        all = true;
+        return ANode.this;
       }
     };
   }
@@ -450,12 +468,12 @@
   /**
    * Adds children of a sub node.
    * @param ch child nodes
-   * @param nc node cache
+   * @param nb node cache
    */
-  static void addDesc(final AxisMoreIter ch, final NodeSeqBuilder nc) {
+  static void addDesc(final BasicNodeIter ch, final ANodeList nb) {
     for(ANode n; (n = ch.next()) != null;) {
-      nc.add(n.finish());
-      addDesc(n.children(), nc);
+      nb.add(n.finish());
+      addDesc(n.children(), nb);
     }
   }
 
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/node/DBNode.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/node/DBNode.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/node/DBNode.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/node/DBNode.java	2015-07-14 10:54:40.000000000 +0000
@@ -30,11 +30,9 @@
  */
 public class DBNode extends ANode {
   /** Data reference. */
-  public final Data data;
+  private final Data data;
   /** Pre value. */
-  public int pre;
-  /** Namespaces. */
-  private Atts nsp;
+  private int pre;
 
   /**
    * Constructor, creating a document node from the specified data reference.
@@ -104,7 +102,6 @@
     type = type(k);
     parent = null;
     value = null;
-    nsp = null;
     pre = p;
   }
 
@@ -113,6 +110,22 @@
     return data;
   }
 
+  /**
+   * Assigns a pre value.
+   * @param p pre value
+   */
+  public final void pre(final int p) {
+    pre = p;
+  }
+
+  /**
+   * Returns the pre value.
+   * @return pre value
+   */
+  public final int pre() {
+    return pre;
+  }
+
   @Override
   public final byte[] string() {
     if(value == null) value = data.atom(pre);
@@ -162,23 +175,14 @@
   @Override
   public final QNm qname(final QNm name) {
     // update the name and uri strings in the specified QName
-    final byte[] nm = name();
-    byte[] uri = Token.EMPTY;
-    final boolean pref = Token.indexOf(nm, ':') != -1;
-    if(pref || data.nspaces.size() != 0) {
-      final int n = pref ? data.nspaces.uri(nm, pre, data) :
-        data.uri(pre, data.kind(pre));
-      final byte[] u = n > 0 ? data.nspaces.uri(n) : pref ? NSGlobal.uri(Token.prefix(nm)) : null;
-      if(u != null) uri = u;
-    }
-    name.set(nm, uri);
+    final byte[][] qname = data.qname(pre, kind());
+    name.set(qname[0], qname[1]);
     return name;
   }
 
   @Override
   public final Atts namespaces() {
-    if(type == NodeType.ELM && nsp == null) nsp = data.ns(pre);
-    return nsp;
+    return data.namespaces(pre);
   }
 
   @Override
@@ -257,180 +261,171 @@
   }
 
   @Override
-  protected final DBNode parent(final ANode p) {
-    parent = p;
+  protected final DBNode parent(final ANode par) {
+    parent = par;
     return this;
   }
 
   @Override
   public final boolean hasChildren() {
-    final int k = data.kind(pre);
-    return data.attSize(pre, k) != data.size(pre, k);
+    final int kind = data.kind(pre);
+    return data.attSize(pre, kind) != data.size(pre, kind);
   }
 
   @Override
-  public final AxisIter ancestor() {
-    return new AxisIter() {
+  public final BasicNodeIter ancestor() {
+    return new BasicNodeIter() {
       private final DBNode node = copy();
-      int p = pre, k = data.kind(p);
+      int curr = pre, kind = data.kind(curr);
 
       @Override
       public ANode next() {
-        p = data.parent(p, k);
-        if(p == -1) return null;
-        k = data.kind(p);
-        node.set(p, k);
+        curr = data.parent(curr, kind);
+        if(curr == -1) return null;
+        kind = data.kind(curr);
+        node.set(curr, kind);
         return node;
       }
     };
   }
 
   @Override
-  public final AxisIter ancestorOrSelf() {
-    return new AxisIter() {
+  public final BasicNodeIter ancestorOrSelf() {
+    return new BasicNodeIter() {
       private final DBNode node = copy();
-      int p = pre, k = data.kind(p);
+      int curr = pre, kind = data.kind(curr);
 
       @Override
       public ANode next() {
-        if(p == -1) return null;
-        k = data.kind(p);
-        node.set(p, k);
-        p = data.parent(p, k);
+        if(curr == -1) return null;
+        kind = data.kind(curr);
+        node.set(curr, kind);
+        curr = data.parent(curr, kind);
         return node;
       }
     };
   }
 
   @Override
-  public final AxisMoreIter attributes() {
-    return new AxisMoreIter() {
+  public final BasicNodeIter attributes() {
+    return new BasicNodeIter() {
       final DBNode node = copy();
-      final int s = pre + data.attSize(pre, data.kind(pre));
-      int p = pre + 1;
-
-      @Override
-      public boolean more() {
-        return p != s;
-      }
+      final int last = pre + data.attSize(pre, data.kind(pre));
+      int curr = pre + 1;
 
       @Override
       public DBNode next() {
-        if(!more()) return null;
-        node.set(p++, Data.ATTR);
-        return node;
+        if(curr == last) return null;
+        final DBNode n = node;
+        n.set(curr++, Data.ATTR);
+        return n;
       }
     };
   }
 
   @Override
-  public final AxisMoreIter children() {
-    return new AxisMoreIter() {
-      int k = data.kind(pre), p = pre + data.attSize(pre, k);
-      final int s = pre + data.size(pre, k);
+  public final BasicNodeIter children() {
+    return new BasicNodeIter() {
+      int kind = data.kind(pre), curr = pre + data.attSize(pre, kind);
+      final int last = pre + data.size(pre, kind);
       final DBNode node = copy();
 
       @Override
-      public boolean more() {
-        return p < s;
-      }
-
-      @Override
       public ANode next() {
-        if(!more()) return null;
-        k = data.kind(p);
-        node.set(p, k);
-        p += data.size(p, k);
+        if(curr == last) return null;
+        final Data d = data;
+        kind = d.kind(curr);
+        node.set(curr, kind);
+        curr += d.size(curr, kind);
         return node;
       }
     };
   }
 
   @Override
-  public final AxisIter descendant() {
-    return new AxisIter() {
-      int k = data.kind(pre), p = pre + data.attSize(pre, k);
-      final int s = pre + data.size(pre, k);
+  public final BasicNodeIter descendant() {
+    return new BasicNodeIter() {
+      int kind = data.kind(pre), curr = pre + data.attSize(pre, kind);
+      final int last = pre + data.size(pre, kind);
       final DBNode node = copy();
 
       @Override
       public DBNode next() {
-        if(p == s) return null;
-        k = data.kind(p);
-        node.set(p, k);
-        p += data.attSize(p, k);
+        if(curr == last) return null;
+        kind = data.kind(curr);
+        node.set(curr, kind);
+        curr += data.attSize(curr, kind);
         return node;
       }
     };
   }
 
   @Override
-  public final AxisIter descendantOrSelf() {
-    return new AxisIter() {
+  public final BasicNodeIter descendantOrSelf() {
+    return new BasicNodeIter() {
       final DBNode node = copy();
-      final int s = pre + data.size(pre, data.kind(pre));
-      int p = pre;
+      final int last = pre + data.size(pre, data.kind(pre));
+      int curr = pre;
 
       @Override
       public ANode next() {
-        if(p == s) return null;
-        final int k = data.kind(p);
-        node.set(p, k);
-        p += data.attSize(p, k);
+        if(curr == last) return null;
+        final int k = data.kind(curr);
+        node.set(curr, k);
+        curr += data.attSize(curr, k);
         return node;
       }
     };
   }
 
   @Override
-  public final AxisIter following() {
-    return new AxisIter() {
+  public final BasicNodeIter following() {
+    return new BasicNodeIter() {
       private final DBNode node = copy();
-      final int s = data.meta.size;
-      int k = data.kind(pre);
-      int p = pre + data.size(pre, k);
+      final int sz = data.meta.size;
+      int kind = data.kind(pre);
+      int curr = pre + data.size(pre, kind);
 
       @Override
       public ANode next() {
-        if(p == s) return null;
-        k = data.kind(p);
-        node.set(p, k);
-        p += data.attSize(p, k);
+        if(curr == sz) return null;
+        kind = data.kind(curr);
+        node.set(curr, kind);
+        curr += data.attSize(curr, kind);
         return node;
       }
     };
   }
 
   @Override
-  public final AxisIter followingSibling() {
-    return new AxisIter() {
+  public final BasicNodeIter followingSibling() {
+    return new BasicNodeIter() {
       private final DBNode node = copy();
-      int k = data.kind(pre);
-      private final int pp = data.parent(pre, k);
-      final int s = pp == -1 ? 0 : pp + data.size(pp, data.kind(pp));
-      int p = pp == -1 ? 0 : pre + data.size(pre, k);
+      int kind = data.kind(pre);
+      private final int pp = data.parent(pre, kind);
+      final int sz = pp == -1 ? 0 : pp + data.size(pp, data.kind(pp));
+      int curr = pp == -1 ? 0 : pre + data.size(pre, kind);
 
       @Override
       public ANode next() {
-        if(p == s) return null;
-        k = data.kind(p);
-        node.set(p, k);
-        p += data.size(p, k);
+        if(curr == sz) return null;
+        kind = data.kind(curr);
+        node.set(curr, kind);
+        curr += data.size(curr, kind);
         return node;
       }
     };
   }
 
   @Override
-  public final AxisIter parentIter() {
-    return new AxisIter() {
-      /** First call. */
-      private boolean more;
+  public final BasicNodeIter parentIter() {
+    return new BasicNodeIter() {
+      private boolean all;
 
       @Override
       public ANode next() {
-        if(more) return null;
-        more = true;
+        if(all) return null;
+        all = true;
         return parent();
       }
     };
@@ -459,8 +454,9 @@
     // check if a document has a single element as child
     ID t = type.id();
     if(type == NodeType.DOC) {
-      final AxisMoreIter ai = children();
-      if(ai.more() && ai.next().type == NodeType.ELM && !ai.more()) t = NodeType.DEL.id();
+      final BasicNodeIter ir = children();
+      final ANode n = ir.next();
+      if(n != null && n.type == NodeType.ELM && ir.next() == null) t = NodeType.DEL.id();
     }
     return t;
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/node/FDoc.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/node/FDoc.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/node/FDoc.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/node/FDoc.java	2015-07-14 10:54:40.000000000 +0000
@@ -96,7 +96,7 @@
   }
 
   @Override
-  public AxisMoreIter children() {
+  public BasicNodeIter children() {
     return iter(children);
   }
 
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/node/FElem.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/node/FElem.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/node/FElem.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/node/FElem.java	2015-07-14 10:54:40.000000000 +0000
@@ -93,16 +93,7 @@
    * @param name element name
    */
   public FElem(final QNm name) {
-    this(name, null);
-  }
-
-  /**
-   * Constructor for creating an element with namespace declarations.
-   * @param name element name
-   * @param ns namespaces
-   */
-  private FElem(final QNm name, final Atts ns) {
-    this(name, ns, null, null);
+    this(name, null, null, null);
   }
 
   /**
@@ -381,12 +372,12 @@
   }
 
   @Override
-  public AxisMoreIter attributes() {
+  public BasicNodeIter attributes() {
     return atts != null ? iter(atts) : super.attributes();
   }
 
   @Override
-  public AxisMoreIter children() {
+  public BasicNodeIter children() {
     return children != null ? iter(children) : super.children();
   }
 
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/node/FNode.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/node/FNode.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/node/FNode.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/node/FNode.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,5 +1,7 @@
 package org.basex.query.value.node;
 
+import java.util.*;
+
 import org.basex.core.*;
 import org.basex.query.iter.*;
 import org.basex.query.util.list.*;
@@ -59,8 +61,8 @@
   }
 
   @Override
-  public final AxisIter ancestor() {
-    return new AxisIter() {
+  public final BasicNodeIter ancestor() {
+    return new BasicNodeIter() {
       private ANode node = FNode.this;
 
       @Override
@@ -72,8 +74,8 @@
   }
 
   @Override
-  public final AxisIter ancestorOrSelf() {
-    return new AxisIter() {
+  public final BasicNodeIter ancestorOrSelf() {
+    return new BasicNodeIter() {
       private ANode node = FNode.this;
 
       @Override
@@ -87,18 +89,18 @@
   }
 
   @Override
-  public AxisMoreIter attributes() {
-    return AxisMoreIter.EMPTY;
+  public BasicNodeIter attributes() {
+    return BasicNodeIter.EMPTY;
   }
 
   @Override
-  public AxisMoreIter children() {
-    return AxisMoreIter.EMPTY;
+  public BasicNodeIter children() {
+    return BasicNodeIter.EMPTY;
   }
 
   @Override
-  public final FNode parent(final ANode p) {
-    parent = p;
+  public final FNode parent(final ANode par) {
+    parent = par;
     return this;
   }
 
@@ -108,12 +110,12 @@
   }
 
   @Override
-  public final AxisIter descendant() {
+  public final BasicNodeIter descendant() {
     return desc(false);
   }
 
   @Override
-  public final AxisIter descendantOrSelf() {
+  public final BasicNodeIter descendantOrSelf() {
     return desc(true);
   }
 
@@ -122,13 +124,11 @@
    * @param iter iterator
    * @return node iterator
    */
-  static AxisMoreIter iter(final ANodeList iter) {
-    return new AxisMoreIter() {
-      /** Child counter. */ int c;
-      @Override
-      public boolean more() { return iter != null && c != iter.size(); }
+  static BasicNodeIter iter(final ANodeList iter) {
+    return new BasicNodeIter() {
+      int c;
       @Override
-      public ANode next() { return more() ? iter.get(c++) : null; }
+      public ANode next() { return iter != null && c != iter.size() ? iter.get(c++) : null; }
       @Override
       public ANode get(final long i) { return iter.get((int) i); }
       @Override
@@ -159,90 +159,84 @@
    * @param self include self node
    * @return node iterator
    */
-  private AxisIter desc(final boolean self) {
-    return new AxisIter() {
-      /** Iterator. */
-      private AxisMoreIter[] nm = new AxisMoreIter[1];
-      /** Iterator Level. */
-      private int l;
+  private BasicNodeIter desc(final boolean self) {
+    return new BasicNodeIter() {
+      private final Stack<BasicNodeIter> iters = new Stack<>();
+      private ANode last;
 
       @Override
       public ANode next() {
-        if(nm[0] == null) nm[0] = self ? self() : children();
-        if(l < 0) return null;
-
-        final ANode node = nm[l].next();
-        if(node != null) {
-          final AxisMoreIter ch = node.children();
-          if(ch.more()) {
-            if(l + 1 == nm.length) nm = Array.copy(nm, new AxisMoreIter[l + 1 << 1]);
-            nm[++l] = ch;
-          } else {
-            while(!nm[l].more()) if(l-- <= 0) break;
+        final BasicNodeIter iter = last != null ? last.children() : self ? self() : children();
+        last = iter.next();
+        if(last == null) {
+          while(!iters.isEmpty()) {
+            last = iters.peek().next();
+            if(last != null) break;
+            iters.pop();
           }
+        } else {
+          iters.add(iter);
         }
-        return node;
+        return last;
       }
     };
   }
 
   @Override
-  public final AxisIter parentIter() {
-    return new AxisIter() {
-      /** First call. */
-      private boolean more;
+  public final BasicNodeIter parentIter() {
+    return new BasicNodeIter() {
+      private boolean all;
 
       @Override
       public ANode next() {
-        return (more ^= true) ? parent : null;
+        if(all) return null;
+        all = true;
+        return parent;
       }
     };
   }
 
   @Override
-  public final AxisIter followingSibling() {
-    return new AxisIter() {
-      /** Iterator. */
-      private AxisIter ai;
+  public final BasicNodeIter followingSibling() {
+    return new BasicNodeIter() {
+      private BasicNodeIter iter;
 
       @Override
       public ANode next() {
-        if(ai == null) {
+        if(iter == null) {
           final ANode r = parent();
           if(r == null) return null;
-          ai = r.children();
-          for(ANode n; (n = ai.next()) != null && !n.is(FNode.this););
+          iter = r.children();
+          for(ANode n; (n = iter.next()) != null && !n.is(FNode.this););
         }
-        return ai.next();
+        return iter.next();
       }
     };
   }
 
   @Override
-  public final AxisIter following() {
-    return new AxisIter() {
-      /** Iterator. */
-      private NodeSeqBuilder nc;
+  public final BasicNodeIter following() {
+    return new BasicNodeIter() {
+      private BasicNodeIter iter;
 
       @Override
       public ANode next() {
-        if(nc == null) {
-          nc = new NodeSeqBuilder();
-          ANode n = FNode.this;
-          ANode p = n.parent();
-          while(p != null) {
-            final AxisIter i = p.children();
-            for(ANode c; n.type != NodeType.ATT &&
-              (c = i.next()) != null && !c.is(n););
-            for(ANode c; (c = i.next()) != null;) {
-              nc.add(c.finish());
-              addDesc(c.children(), nc);
+        if(iter == null) {
+          final ANodeList list = new ANodeList();
+          ANode node = FNode.this, par = node.parent();
+          while(par != null) {
+            final BasicNodeIter i = par.children();
+            for(ANode n; node.type != NodeType.ATT && (n = i.next()) != null && !n.is(node););
+            for(ANode n; (n = i.next()) != null;) {
+              list.add(n.finish());
+              addDesc(n.children(), list);
             }
-            n = p;
-            p = p.parent();
+            node = par;
+            par = par.parent();
           }
+          iter = list.iter();
         }
-        return nc.next();
+        return iter.next();
       }
     };
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/node/FTNode.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/node/FTNode.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/node/FTNode.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/node/FTNode.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,6 +1,7 @@
 package org.basex.query.value.node;
 
 import org.basex.data.*;
+import org.basex.query.util.ft.*;
 import org.basex.query.value.type.*;
 import org.basex.util.ft.*;
 
@@ -16,47 +17,63 @@
   /** Total number of indexed results. */
   private final int is;
   /** Full-text matches. */
-  public FTMatches all;
+  private FTMatches matches;
 
   /**
    * Constructor, called by the sequential variant.
-   * @param all matches
+   * @param matches matches
    * @param score scoring
    */
-  public FTNode(final FTMatches all, final double score) {
-    this(all, null, 0, 0, 0, score);
+  public FTNode(final FTMatches matches, final double score) {
+    this(matches, null, 0, 0, 0, score);
   }
 
   /**
    * Constructor, called by the index variant.
-   * @param all full-text matches
+   * @param matches full-text matches
    * @param d data reference
    * @param p pre value
    * @param tl token length
    * @param is number of indexed results
    * @param score score value out of the index
    */
-  public FTNode(final FTMatches all, final Data d, final int p, final int tl, final int is,
+  public FTNode(final FTMatches matches, final Data d, final int p, final int tl, final int is,
       final double score) {
 
     super(d, p, null, NodeType.TXT);
-    this.all = all;
+    this.matches = matches;
     this.tl = tl;
     this.is = is;
     if(score != -1) this.score = score;
   }
 
+  /**
+   * Assigns full-text matches.
+   * @param match full-text matches
+   */
+  public void matches(final FTMatches match) {
+    matches = match;
+  }
+
+  /**
+   * Returns full-text matches.
+   * @return full-text matches
+   */
+  public FTMatches matches() {
+    return matches;
+  }
+
   @Override
   public double score() {
     if(score == null) {
-      if(all == null) return 0;
-      score = Scoring.textNode(all.size(), is, tl, data.textLen(pre, true));
+      if(matches == null) return 0;
+      score = Scoring.textNode(matches.size(), is, tl, data().textLen(pre(), true));
     }
     return score;
   }
 
   @Override
   public String toString() {
-    return super.toString() + (all != null ? " (" + all.size() + ')' : "");
+    return super.toString() + (matches != null ? " (" + matches.size() + ')' : "");
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/node/FTPosNode.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/node/FTPosNode.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/node/FTPosNode.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/node/FTPosNode.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,6 +1,7 @@
 package org.basex.query.value.node;
 
 import org.basex.data.*;
+import org.basex.query.util.ft.*;
 
 /**
  * Database node with full-text positions.
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/BlnSeq.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/BlnSeq.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/BlnSeq.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/BlnSeq.java	2015-07-14 10:54:40.000000000 +0000
@@ -9,7 +9,7 @@
 import org.basex.query.value.type.*;
 
 /**
- * Sequence of items of type {@link Int xs:boolean}, containing at least two of them.
+ * Sequence of items of type {@link Bln xs:boolean}, containing at least two of them.
  *
  * @author BaseX Team 2005-15, BSD License
  * @author Christian Gruen
@@ -42,14 +42,6 @@
     return values;
   }
 
-  @Override
-  public Value reverse() {
-    final int s = values.length;
-    final boolean[] tmp = new boolean[s];
-    for(int l = 0, r = s - 1; l < s; l++, r--) tmp[l] = values[r];
-    return get(tmp);
-  }
-
   // STATIC METHODS =====================================================================
 
   /**
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/BytSeq.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/BytSeq.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/BytSeq.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/BytSeq.java	2015-07-14 10:54:40.000000000 +0000
@@ -41,14 +41,6 @@
     return values;
   }
 
-  @Override
-  public Value reverse() {
-    final int s = values.length;
-    final byte[] tmp = new byte[s];
-    for(int l = 0, r = s - 1; l < s; l++, r--) tmp[l] = values[r];
-    return get(tmp);
-  }
-
   // STATIC METHODS =====================================================================
 
   /**
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/DblSeq.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/DblSeq.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/DblSeq.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/DblSeq.java	2015-07-14 10:54:40.000000000 +0000
@@ -42,14 +42,6 @@
     return values;
   }
 
-  @Override
-  public Value reverse() {
-    final int s = values.length;
-    final double[] tmp = new double[s];
-    for(int l = 0, r = s - 1; l < s; l++, r--) tmp[l] = values[r];
-    return get(tmp);
-  }
-
   // STATIC METHODS =====================================================================
 
   /**
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/DBNodeSeq.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/DBNodeSeq.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/DBNodeSeq.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/DBNodeSeq.java	2015-07-14 10:54:40.000000000 +0000
@@ -6,7 +6,6 @@
 import org.basex.data.*;
 import org.basex.query.*;
 import org.basex.query.expr.*;
-import org.basex.query.iter.*;
 import org.basex.query.value.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.node.*;
@@ -20,22 +19,22 @@
  * @author BaseX Team 2005-15, BSD License
  * @author Christian Gruen
  */
-public final class DBNodeSeq extends NativeSeq {
+public class DBNodeSeq extends NativeSeq {
   /** Data reference. */
-  private final Data data;
+  protected final Data data;
   /** Pre values. */
-  public final int[] pres;
-  /** Pre values comprise all documents of the database. */
-  public final boolean all;
+  protected int[] pres;
+  /** Pre values reference all documents of the database. */
+  protected boolean all;
 
   /**
    * Constructor.
    * @param pres pre values
    * @param data data reference
    * @param type node type
-   * @param all pre values comprise all documents of the database
+   * @param all pre values reference all documents of the database
    */
-  private DBNodeSeq(final int[] pres, final Data data, final Type type, final boolean all) {
+  protected DBNodeSeq(final int[] pres, final Data data, final Type type, final boolean all) {
     super(pres.length, type);
     this.pres = pres;
     this.data = data;
@@ -70,20 +69,37 @@
   }
 
   @Override
-  public Value reverse() {
-    final int s = pres.length;
-    final int[] tmp = new int[s];
-    for(int l = 0, r = s - 1; l < s; l++, r--) tmp[l] = pres[r];
-    return get(tmp, data, type, false);
-  }
-
-  @Override
   public Value atomValue(final InputInfo ii) throws QueryException {
-    final ValueBuilder vb = new ValueBuilder((int) size);
+    final ValueBuilder vb = new ValueBuilder();
     for(int s = 0; s < size; s++) vb.add(itemAt(s).atomValue(ii));
     return vb.value();
   }
 
+  /**
+   * Returns the internal pre value array.
+   * @return pre values
+   */
+  public int[] pres() {
+    return pres;
+  }
+
+  /**
+   * Returns the specified pre value.
+   * @param index index of pre value
+   * @return pre value
+   */
+  public int pre(final int index) {
+    return pres[index];
+  }
+
+  /**
+   * Indicates if pre values reference all documents of the database.
+   * @return flag
+   */
+  public boolean all() {
+    return all;
+  }
+
   @Override
   public String toString() {
     final StringBuilder sb = new StringBuilder(PAREN1);
@@ -105,7 +121,7 @@
    * @param pres pre values
    * @param data data reference
    * @param docs all values reference document nodes
-   * @param all pre values comprise all documents of the database
+   * @param all pre values reference all documents of the database
    * @return resulting item or sequence
    */
   public static Value get(final IntList pres, final Data data, final boolean docs,
@@ -118,7 +134,7 @@
    * @param pres pre values
    * @param data data reference
    * @param type node type
-   * @param all pre values comprise all documents of the database
+   * @param all pre values reference all documents of the database
    * @return resulting item or sequence
    */
   private static Value get(final int[] pres, final Data data, final Type type, final boolean all) {
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/DBNodes.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/DBNodes.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/DBNodes.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/DBNodes.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,207 @@
+package org.basex.query.value.seq;
+
+import java.util.*;
+
+import org.basex.core.Context;
+import org.basex.data.*;
+import org.basex.query.*;
+import org.basex.query.expr.*;
+import org.basex.query.util.ft.*;
+import org.basex.query.value.node.*;
+import org.basex.query.value.type.*;
+import org.basex.util.list.*;
+
+/**
+ * This class stores database nodes in an ascending order.
+ * Instances of this class will be returned by the method {@link QueryProcessor#cache(int)} method.
+ * They are used in the GUI and in the {@link Context} class to reference currently opened,
+ * marked, and copied database nodes.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Christian Gruen
+ */
+public final class DBNodes extends DBNodeSeq {
+  /** Full-text position data (can be {@code null}). */
+  private FTPosData ftpos;
+  /** Sorted pre values (can be {@code null}). */
+  private int[] sorted;
+
+  /**
+   * Constructor, specifying a database and pre values.
+   * @param data data reference
+   * @param pres pre values
+   */
+  public DBNodes(final Data data, final int... pres) {
+    this(data, false, pres);
+  }
+
+  /**
+   * Constructor, specifying a database, pre values and full-text positions.
+   * @param all pre values reference all documents of the database
+   * @param data data reference
+   * @param pres pre values
+   */
+  public DBNodes(final Data data, final boolean all, final int... pres) {
+    super(pres, data, all ? NodeType.DOC : NodeType.NOD, all);
+  }
+
+  /**
+   * Assigns full-text position data.
+   * @param ft full-text positions
+   * @return self reference
+   */
+  public DBNodes ftpos(final FTPosData ft) {
+    ftpos = ft;
+    return this;
+  }
+
+  /**
+   * Returns full-text position data.
+   * @return position data
+   */
+  public FTPosData ftpos() {
+    return ftpos;
+  }
+
+  @Override
+  public boolean sameAs(final Expr cmp) {
+    if(!(cmp instanceof DBNodes)) return false;
+    final DBNodes n = (DBNodes) cmp;
+    final int[] ps = pres, ps2 = n.pres;
+    final int pl = ps.length;
+    if(pl != ps2.length || data != n.data) return false;
+    for(int p = 0; p < pl; ++p) if(ps2[p] != ps[p]) return false;
+    return ftpos == null ? n.ftpos == null : ftpos.sameAs(n.ftpos);
+  }
+
+  /**
+   * Returns {@code null} if the pre values reference all documents of the database.
+   * @return self reference or {@code null}
+   */
+  public DBNodes discardDocs() {
+    if(all) return null;
+
+    final IntList docs = data.resources.docs();
+    final int[] ps = pres;
+    final int pl = ps.length;
+    if(pl != docs.size()) return this;
+
+    int c = -1;
+    while(++c < pl && ps[c] == docs.get(c));
+    return c < pl ? this : null;
+  }
+
+  /**
+   * Checks if the specified node is contained in the array.
+   * @param pre pre value
+   * @return true if the node was found
+   */
+  public boolean contains(final int pre) {
+    return find(pre) >= 0;
+  }
+
+  /**
+   * Returns the position of the specified node or the negative value - 1 of
+   * the position where it should have been found.
+   * @param pre pre value
+   * @return position, or {@code -1}
+   */
+  public int find(final int pre) {
+    sort();
+    return Arrays.binarySearch(sorted, pre);
+  }
+
+  /**
+   * Adds or removes the specified pre node.
+   * @param pre pre value
+   */
+  public void toggle(final int pre) {
+    final int[] n = { pre };
+    pres = contains(pre) ? except(pres, n) : union(pres, n);
+    sorted = null;
+  }
+
+  /**
+   * Merges the specified array with the existing pre nodes.
+   * @param pre pre value
+   */
+  public void union(final int[] pre) {
+    pres = union(pres, pre);
+    sorted = null;
+  }
+
+  /**
+   * Merges two sorted integer arrays via union.
+   * Note that the input arrays must be sorted.
+   * @param pres1 first set
+   * @param pres2 second set
+   * @return resulting set
+   */
+  private static int[] union(final int[] pres1, final int[] pres2) {
+    final int al = pres1.length, bl = pres2.length;
+    final IntList il = new IntList();
+    int a = 0, b = 0;
+    while(a != al && b != bl) {
+      final int d = pres1[a] - pres2[b];
+      il.add(d <= 0 ? pres1[a++] : pres2[b++]);
+      if(d == 0) ++b;
+    }
+    while(a != al) il.add(pres1[a++]);
+    while(b != bl) il.add(pres2[b++]);
+    return il.finish();
+  }
+
+  /**
+   * Subtracts the second from the first array.
+   * Note that the input arrays must be sorted.
+   * @param pres1 first set
+   * @param pres2 second set
+   * @return resulting set
+   */
+  private static int[] except(final int[] pres1, final int[] pres2) {
+    final int al = pres1.length, bl = pres2.length;
+    final IntList il = new IntList();
+    int a = 0, b = 0;
+    while(a != al && b != bl) {
+      final int d = pres1[a] - pres2[b];
+      if(d < 0) il.add(pres1[a]);
+      else ++b;
+      if(d <= 0) ++a;
+    }
+    while(a != al) il.add(pres1[a++]);
+    return il.finish();
+  }
+
+  /**
+   * Creates a sorted node array. If the original array is already sorted,
+   * the same reference is used.
+   */
+  private void sort() {
+    if(sorted != null) return;
+    int min = Integer.MIN_VALUE;
+    for(final int pre : pres) {
+      if(pre < min) {
+        sorted = Arrays.copyOf(pres, pres.length);
+        Arrays.sort(sorted);
+        return;
+      }
+      min = pre;
+    }
+    sorted = pres;
+  }
+
+  /**
+   * Returns a sorted pre value.
+   * @param index index of pre value
+   * @return pre value
+   */
+  public int sorted(final int index) {
+    return sorted[index];
+  }
+
+  @Override
+  public DBNode itemAt(final long pos) {
+    final int pre = pres[(int) pos];
+    return ftpos == null ? new DBNode(data, pre) : new FTPosNode(data, pre, ftpos);
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/DecSeq.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/DecSeq.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/DecSeq.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/DecSeq.java	2015-07-14 10:54:40.000000000 +0000
@@ -43,14 +43,6 @@
     return values;
   }
 
-  @Override
-  public Value reverse() {
-    final int s = values.length;
-    final BigDecimal[] tmp = new BigDecimal[s];
-    for(int l = 0, r = s - 1; l < s; l++, r--) tmp[l] = values[r];
-    return get(tmp);
-  }
-
   // STATIC METHODS =====================================================================
 
   /**
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/Empty.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/Empty.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/Empty.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/Empty.java	2015-07-14 10:54:40.000000000 +0000
@@ -100,11 +100,21 @@
   }
 
   @Override
+  public Value reverse() {
+    return this;
+  }
+
+  @Override
   public boolean homogeneous() {
     return true;
   }
 
   @Override
+  public Value subSeq(final long start, final long len) {
+    return this;
+  }
+
+  @Override
   public Value materialize(final InputInfo ii) {
     return this;
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/FltSeq.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/FltSeq.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/FltSeq.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/FltSeq.java	2015-07-14 10:54:40.000000000 +0000
@@ -42,14 +42,6 @@
     return values;
   }
 
-  @Override
-  public Value reverse() {
-    final int s = values.length;
-    final float[] tmp = new float[s];
-    for(int l = 0, r = s - 1; l < s; l++, r--) tmp[l] = values[r];
-    return get(tmp);
-  }
-
   // STATIC METHODS =====================================================================
 
   /**
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/IntSeq.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/IntSeq.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/IntSeq.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/IntSeq.java	2015-07-14 10:54:40.000000000 +0000
@@ -62,14 +62,6 @@
     }
   }
 
-  @Override
-  public Value reverse() {
-    final int s = values.length;
-    final long[] tmp = new long[s];
-    for(int l = 0, r = s - 1; l < s; l++, r--) tmp[l] = values[r];
-    return get(tmp, type);
-  }
-
   // STATIC METHODS =====================================================================
 
   /**
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/ItemSeq.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/ItemSeq.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/ItemSeq.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/ItemSeq.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,129 +0,0 @@
-package org.basex.query.value.seq;
-
-import static org.basex.query.QueryError.*;
-
-import org.basex.query.*;
-import org.basex.query.expr.*;
-import org.basex.query.iter.*;
-import org.basex.query.value.*;
-import org.basex.query.value.item.*;
-import org.basex.query.value.node.*;
-import org.basex.query.value.type.*;
-import org.basex.query.value.type.SeqType.Occ;
-import org.basex.util.*;
-
-/**
- * Sequence, containing at least two items.
- *
- * @author BaseX Team 2005-15, BSD License
- * @author Christian Gruen
- */
-final class ItemSeq extends Seq {
-  /** Item array. */
-  private final Item[] items;
-  /** Item Types. */
-  private Type ret;
-
-  /**
-   * Constructor.
-   * @param items items
-   * @param size size
-   * @param ret sequence type
-   */
-  ItemSeq(final Item[] items, final int size, final Type ret) {
-    super(size);
-    this.items = items;
-    this.ret = ret;
-  }
-
-  @Override
-  public Item ebv(final QueryContext qc, final InputInfo ii) throws QueryException {
-    if(items[0] instanceof ANode) return items[0];
-    throw EBV_X.get(ii, this);
-  }
-
-  @Override
-  public SeqType seqType() {
-    if(ret == null) {
-      Type t = items[0].type;
-      for(int s = 1; s < size; s++) {
-        if(t != items[s].type) {
-          t = AtomType.ITEM;
-          break;
-        }
-      }
-      ret = t;
-      type = t;
-    }
-    return SeqType.get(ret, Occ.ONE_MORE);
-  }
-
-  @Override
-  public boolean iterable() {
-    return false;
-  }
-
-  @Override
-  public boolean sameAs(final Expr cmp) {
-    if(!(cmp instanceof ItemSeq)) return false;
-    final ItemSeq is = (ItemSeq) cmp;
-    return items == is.items && size == is.size;
-  }
-
-  @Override
-  public int writeTo(final Item[] arr, final int index) {
-    System.arraycopy(items, 0, arr, index, (int) size);
-    return (int) size;
-  }
-
-  @Override
-  public Item itemAt(final long pos) {
-    return items[(int) pos];
-  }
-
-  @Override
-  public boolean homogeneous() {
-    return ret != null && ret != AtomType.ITEM;
-  }
-
-  @Override
-  public Value reverse() {
-    final int s = items.length;
-    final Item[] tmp = new Item[s];
-    for(int l = 0, r = s - 1; l < s; l++, r--) tmp[l] = items[r];
-    return get(tmp, s, type);
-  }
-
-  @Override
-  public boolean has(final Flag flag) {
-    if(flag == Flag.UPD) {
-      for(int l = 0; l < size; l++) {
-        if(items[l].has(Flag.UPD)) return true;
-      }
-    }
-    return false;
-  }
-
-  @Override
-  public Value materialize(final InputInfo ii) throws QueryException {
-    final int s = (int) size;
-    final ValueBuilder vb = new ValueBuilder(s);
-    for(int i = 0; i < s; i++) vb.add(itemAt(i).materialize(ii));
-    return vb.value();
-  }
-
-  @Override
-  public Value atomValue(final InputInfo ii) throws QueryException {
-    final int s = (int) size;
-    final ValueBuilder vb = new ValueBuilder(s);
-    for(int i = 0; i < s; i++) vb.add(itemAt(i).atomValue(ii));
-    return vb.value();
-  }
-
-  @Override
-  public long atomSize() {
-    long s = 0;
-    for(int i = 0; i < size; i++) s += itemAt(i).atomSize();
-    return s;
-  }
-}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/NativeSeq.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/NativeSeq.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/NativeSeq.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/NativeSeq.java	2015-07-14 10:54:40.000000000 +0000
@@ -61,4 +61,22 @@
   public final SeqType seqType() {
     return SeqType.get(type, Occ.ONE_MORE);
   }
+
+  @Override
+  public final Value insert(final long pos, final Item item) {
+    return copyInsert(pos, item);
+  }
+
+  @Override
+  public final Value remove(final long pos) {
+    return size == 1 ? itemAt(1 - pos) : copyRemove(pos);
+  }
+
+  @Override
+  public final Value reverse() {
+    final int n = (int) size;
+    final ValueBuilder vb = new ValueBuilder();
+    for(int i = 0; i < n; i++) vb.add(itemAt(n - i - 1));
+    return vb.value(type);
+  }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/RangeSeq.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/RangeSeq.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/RangeSeq.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/RangeSeq.java	2015-07-14 10:54:40.000000000 +0000
@@ -99,6 +99,16 @@
   }
 
   @Override
+  public Value insert(final long pos, final Item item) {
+    return copyInsert(pos, item);
+  }
+
+  @Override
+  public Value remove(final long pos) {
+    return pos == 0 || pos == size - 1 ? subSeq(pos == 0 ? 0 : 1, size - 1) : copyRemove(pos);
+  }
+
+  @Override
   public Value reverse() {
     final long s = size();
     return asc ? get(start + s - 1, s, false) : get(start - s + 1, s, true);
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/Seq.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/Seq.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/Seq.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/Seq.java	2015-07-14 10:54:40.000000000 +0000
@@ -8,6 +8,7 @@
 import org.basex.query.value.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.node.*;
+import org.basex.query.value.seq.tree.*;
 import org.basex.query.value.type.*;
 import org.basex.util.*;
 
@@ -19,13 +20,13 @@
  */
 public abstract class Seq extends Value {
   /** Length. */
-  final long size;
+  protected final long size;
 
   /**
    * Constructor.
    * @param size size
    */
-  Seq(final long size) {
+  protected Seq(final long size) {
     this(size, AtomType.ITEM);
   }
 
@@ -34,41 +35,11 @@
    * @param size size
    * @param type type
    */
-  Seq(final long size, final Type type) {
+  protected Seq(final long size, final Type type) {
     super(type);
     this.size = size;
   }
 
-  /**
-   * Returns a value representation of the specified items.
-   * @param value value
-   * @return resulting item or sequence
-   */
-  public static Value get(final Item[] value) {
-    return get(value, value.length);
-  }
-
-  /**
-   * Returns a value representation of the specified items.
-   * @param value value
-   * @param size size
-   * @return resulting item or sequence
-   */
-  public static Value get(final Item[] value, final int size) {
-    return get(value, size, null);
-  }
-
-  /**
-   * Returns a value representation of the specified items.
-   * @param value value
-   * @param size size
-   * @param type sequence type
-   * @return resulting item or sequence
-   */
-  public static Value get(final Item[] value, final int size, final Type type) {
-    return size == 0 ? Empty.SEQ : size == 1 ? value[0] : new ItemSeq(value, size, type);
-  }
-
   @Override
   public Object toJava() throws QueryException {
     final Object[] obj = new Object[(int) size];
@@ -82,6 +53,11 @@
   }
 
   @Override
+  public final boolean isEmpty() {
+    return false;
+  }
+
+  @Override
   public final Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
     throw SEQFOUND_X.get(ii, this);
   }
@@ -92,7 +68,7 @@
   }
 
   @Override
-  public final ValueIter iter() {
+  public ValueIter iter() {
     return new ValueIter() {
       int c;
       @Override
@@ -107,6 +83,67 @@
   }
 
   @Override
+  public Value subSeq(final long start, final long len) {
+    return len == 0   ? Empty.SEQ
+         : len == 1   ? itemAt(start)
+         : len < size ? new SubSeq(this, start, len)
+                      : this;
+  }
+
+  /**
+   * Inserts a value at the given position into this sequence and returns the resulting sequence.
+   * @param pos position at which the value should be inserted, must be between 0 and {@link #size}
+   * @param val value to insert
+   * @return resulting value
+   */
+  public Value insertBefore(final long pos, final Value val) {
+    final long n = val.size();
+    return n == 1 ? insert(pos, (Item) val) : copyInsert(pos, val);
+  }
+
+  /**
+   * Inserts an item at the given position into this sequence and returns the resulting sequence.
+   * @param pos position at which the item should be inserted, must be between 0 and {@link #size}
+   * @param val value to insert
+   * @return resulting value
+   */
+  public abstract Value insert(final long pos, final Item val);
+
+  /**
+   * Helper for {@link #insertBefore(long, Value)} that copies all items into a {@link TreeSeq}.
+   * @param pos position at which the value should be inserted, must be between 0 and {@link #size}
+   * @param val value to insert
+   * @return resulting value
+   */
+  final Value copyInsert(final long pos, final Value val) {
+    if(val.isEmpty()) return this;
+    final ValueBuilder vb = new ValueBuilder();
+    for(long i = 0; i < pos; i++) vb.add(itemAt(i));
+    vb.add(val);
+    for(long i = pos; i < size; i++) vb.add(itemAt(i));
+    return vb.value(type);
+  }
+
+  /**
+   * Removes the item at the given position in this sequence and returns the resulting sequence.
+   * @param pos position of the item to remove, must be between 0 and {@link #size} - 1
+   * @return resulting sequence
+   */
+  public abstract Value remove(final long pos);
+
+  /**
+   * Helper for {@link #remove(long)} that copies all items into a {@link TreeSeq}.
+   * @param pos position of the item to remove, must be between 0 and {@link #size} - 1
+   * @return resulting sequence
+   */
+  final Value copyRemove(final long pos) {
+    final ValueBuilder vb = new ValueBuilder();
+    for(long i = 0; i < pos; i++) vb.add(itemAt(i));
+    for(long i = pos + 1; i < size; i++) vb.add(itemAt(i));
+    return vb.value(type);
+  }
+
+  @Override
   public final int hash(final InputInfo ii) throws QueryException {
     // final hash function because equivalent sequences *must* produce the
     // same hash value, otherwise they get lost in hash maps.
@@ -122,12 +159,6 @@
     throw SEQFOUND_X.get(ii, this);
   }
 
-  /**
-   * Returns a sequence in reverse order.
-   * @return sequence
-   */
-  public abstract Value reverse();
-
   @Override
   public void plan(final FElem plan) {
     final FElem el = planElem(SIZE, size);
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/StrSeq.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/StrSeq.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/StrSeq.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/StrSeq.java	2015-07-14 10:54:40.000000000 +0000
@@ -47,14 +47,6 @@
     return tmp;
   }
 
-  @Override
-  public Value reverse() {
-    final int vl = values.length;
-    final byte[][] tmp = new byte[vl][];
-    for(int l = 0, r = vl - 1; l < vl; l++, r--) tmp[l] = values[r];
-    return get(tmp);
-  }
-
   // STATIC METHODS =====================================================================
 
   /**
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/SubSeq.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/SubSeq.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/SubSeq.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/SubSeq.java	2015-07-14 10:54:40.000000000 +0000
@@ -3,7 +3,6 @@
 import static org.basex.query.QueryError.*;
 
 import org.basex.query.*;
-import org.basex.query.iter.*;
 import org.basex.query.value.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.node.*;
@@ -16,50 +15,47 @@
  * @author BaseX Team 2005-15, BSD License
  * @author Leo Woerteler
  */
-public final class SubSeq extends Seq {
+final class SubSeq extends Seq {
   /** Underlying sequence. */
   private final Seq sub;
   /** Starting index in {@link #sub}. */
   private final long start;
 
   /**
-   * Factory method for subsequences.
-   * @param val underlying value
-   * @param from starting index
-   * @param len length of the subsequence
-   * @return the resulting value
-   */
-  public static Value get(final Value val, final long from, final long len) {
-    final long vs = val.size(), n = Math.min(vs - from, len);
-    if(n == vs) return val;
-    if(n <= 0) return Empty.SEQ;
-    if(n == 1) return val.itemAt(from);
-    if(val instanceof SubSeq) {
-      final SubSeq ss = (SubSeq) val;
-      return new SubSeq(ss.sub, ss.start + from, n);
-    }
-    // cast is safe because n >= 2
-    return new SubSeq((Seq) val, from, n);
-  }
-
-  /**
    * Constructor.
    * @param sub underlying sequence
    * @param start starting index
    * @param len length of the subsequence
    */
-  private SubSeq(final Seq sub, final long start, final long len) {
+  SubSeq(final Seq sub, final long start, final long len) {
     super(len, sub.type);
     this.sub = sub;
     this.start = start;
   }
 
   @Override
+  public Value subSeq(final long off, final long len) {
+    return len == 0   ? Empty.SEQ
+         : len == 1   ? sub.itemAt(start + off)
+         : len < size ? new SubSeq(sub, start + off, len)
+                      : this;
+  }
+
+  @Override
+  public Value insert(final long pos, final Item item) {
+    return copyInsert(pos, item);
+  }
+
+  @Override
+  public Value remove(final long pos) {
+    return copyRemove(pos);
+  }
+
+  @Override
   public Value reverse() {
-    final int n = (int) size;
-    final Item[] items = new Item[n];
-    for(int i = 0; i < n; i++) items[n - 1 - i] = itemAt(i);
-    return Seq.get(items);
+    final ValueBuilder vb = new ValueBuilder();
+    for(long i = 0; i < size; i++) vb.addFront(sub.itemAt(start + i));
+    return vb.value();
   }
 
   @Override
@@ -93,17 +89,15 @@
 
   @Override
   public Value materialize(final InputInfo ii) throws QueryException {
-    final int s = (int) size;
-    final ValueBuilder vb = new ValueBuilder(s);
-    for(int i = 0; i < s; i++) vb.add(itemAt(i).materialize(ii));
+    final ValueBuilder vb = new ValueBuilder();
+    for(long i = 0; i < size; i++) vb.add(itemAt(i).materialize(ii));
     return vb.value();
   }
 
   @Override
   public Value atomValue(final InputInfo ii) throws QueryException {
-    final int s = (int) size;
-    final ValueBuilder vb = new ValueBuilder(s);
-    for(int i = 0; i < s; i++) vb.add(itemAt(i).atomValue(ii));
+    final ValueBuilder vb = new ValueBuilder();
+    for(long i = 0; i < size; i++) vb.add(itemAt(i).atomValue(ii));
     return vb.value();
   }
 
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/tree/BigSeq.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/tree/BigSeq.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/tree/BigSeq.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/tree/BigSeq.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,572 @@
+package org.basex.query.value.seq.tree;
+
+import java.util.*;
+
+import org.basex.query.iter.*;
+import org.basex.query.util.fingertree.*;
+import org.basex.query.value.*;
+import org.basex.query.value.item.*;
+import org.basex.query.value.seq.*;
+import org.basex.query.value.type.*;
+
+/**
+ * A sequence containing more elements than fit into a {@link SmallSeq}.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Leo Woerteler
+ */
+final class BigSeq extends TreeSeq {
+  /** Left digit. */
+  final Item[] left;
+  /** Middle tree. */
+  final FingerTree<Item, Item> middle;
+  /** Right digit. */
+  final Item[] right;
+
+  /**
+   * Constructor.
+   * @param left left digit
+   * @param middle middle tree
+   * @param right right digit
+   * @param ret type of all items in this sequence, can be {@code null}
+   */
+  BigSeq(final Item[] left, final FingerTree<Item, Item> middle, final Item[] right,
+      final Type ret) {
+    super(left.length + middle.size() + right.length, ret);
+    this.left = left;
+    this.middle = middle;
+    this.right = right;
+    assert left.length >= MIN_DIGIT && left.length <= MAX_DIGIT
+        && right.length >= MIN_DIGIT && right.length <= MAX_DIGIT;
+  }
+
+  @Override
+  public Item itemAt(final long index) {
+    // index out of range?
+    if(index < 0) throw new IndexOutOfBoundsException("Index < 0: " + index);
+    if(index >= size) throw new IndexOutOfBoundsException(index + " >= " + size);
+
+    // index in one of the digits?
+    if(index < left.length) return left[(int) index];
+    final long midSize = size - right.length;
+    if(index >= midSize) return right[(int) (index - midSize)];
+
+    // the element is in the middle tree
+    return middle.get(index - left.length);
+  }
+
+  @Override
+  public TreeSeq reverse() {
+    final int l = left.length, r = right.length;
+    final Item[] newLeft = new Item[r], newRight = new Item[l];
+    for(int i = 0; i < r; i++) newLeft[i] = right[r - 1 - i];
+    for(int i = 0; i < l; i++) newRight[i] = left[l - 1 - i];
+    return new BigSeq(newLeft, middle.reverse(), newRight, ret);
+  }
+
+  @Override
+  public TreeSeq insert(final long pos, final Item val) {
+    if(pos < 0) throw new IndexOutOfBoundsException("negative index: " + pos);
+    if(pos > size()) throw new IndexOutOfBoundsException("position too big: " + pos);
+
+    final int l = left.length;
+    if(pos <= l) {
+      final int p = (int) pos;
+      final Item[] temp = slice(left, 0, l + 1);
+      System.arraycopy(temp, p, temp, p + 1, l - p);
+      temp[p] = val;
+      if(l < MAX_DIGIT) return new BigSeq(temp, middle, right, null);
+
+      final int m = (l + 1) / 2;
+      return new BigSeq(slice(temp, 0, m),
+          middle.cons(new LeafNode(slice(temp, m, l + 1))), right, null);
+    }
+
+    final long midSize = middle.size();
+    if(pos - l < midSize) return new BigSeq(left, middle.insert(pos - l, val), right, null);
+
+    final int r = right.length;
+    final int p = (int) (pos - l - midSize);
+    final Item[] temp = slice(right, 0, r + 1);
+    System.arraycopy(temp, p, temp, p + 1, r - p);
+    temp[p] = val;
+    if(r < MAX_DIGIT) return new BigSeq(left, middle, temp, null);
+
+    final int m = (r + 1) / 2;
+    return new BigSeq(left, middle.snoc(new LeafNode(slice(temp, 0, m))),
+        slice(temp, m, r + 1), null);
+  }
+
+  @Override
+  public TreeSeq remove(final long pos) {
+    if(pos < 0) throw new IndexOutOfBoundsException("negative index: " + pos);
+    if(pos >= size()) throw new IndexOutOfBoundsException("position too big: " + pos);
+
+    if(pos < left.length) {
+      // delete from left digit
+      final int p = (int) pos, l = left.length;
+      if(l > MIN_DIGIT) {
+        // there is enough space, just delete the element
+        final Item[] newLeft = new Item[l - 1];
+        System.arraycopy(left, 0, newLeft, 0, p);
+        System.arraycopy(left, p + 1, newLeft, p, newLeft.length - p);
+        return new BigSeq(newLeft, middle, right, ret);
+      }
+
+      if(middle.isEmpty()) {
+        // merge left and right digit
+        final int r = right.length, n = l - 1 + r;
+        final Item[] vals = new Item[n];
+        System.arraycopy(left, 0, vals, 0, p);
+        System.arraycopy(left, p + 1, vals, p, l - 1 - p);
+        System.arraycopy(right, 0, vals, l - 1, r);
+        return fromMerged(vals, ret);
+      }
+
+      // extract a new left digit from the middle
+      final Item[] head = ((LeafNode) middle.head()).values;
+      final int r = head.length, n = l - 1 + r;
+
+      if(r > MIN_LEAF) {
+        // refill from neighbor
+        final int move = (r - MIN_LEAF + 1) / 2;
+        final Item[] newLeft = new Item[l - 1 + move];
+        System.arraycopy(left, 0, newLeft, 0, p);
+        System.arraycopy(left, p + 1, newLeft, p, l - 1 - p);
+        System.arraycopy(head, 0, newLeft, l - 1, move);
+        final Item[] newHead = slice(head, move, r);
+        return new BigSeq(newLeft, middle.replaceHead(new LeafNode(newHead)), right, ret);
+      }
+
+      // merge digit and head node
+      final Item[] newLeft = new Item[n];
+      System.arraycopy(left, 0, newLeft, 0, p);
+      System.arraycopy(left, p + 1, newLeft, p, l - 1 - p);
+      System.arraycopy(head, 0, newLeft, l - 1, r);
+      return new BigSeq(newLeft, middle.tail(), right, ret);
+    }
+
+    final long midSize = middle.size(), rightOffset = left.length + midSize;
+    if(pos >= rightOffset) {
+      // delete from right digit
+      final int p = (int) (pos - rightOffset), r = right.length;
+      if(r > MIN_DIGIT) {
+        // there is enough space, just delete the element
+        final Item[] newRight = new Item[r - 1];
+        System.arraycopy(right, 0, newRight, 0, p);
+        System.arraycopy(right, p + 1, newRight, p, r - 1 - p);
+        return new BigSeq(left, middle, newRight, ret);
+      }
+
+      if(middle.isEmpty()) {
+        // merge left and right digit
+        final int l = left.length, n = l + r - 1;
+        final Item[] vals = new Item[n];
+        System.arraycopy(left, 0, vals, 0, l);
+        System.arraycopy(right, 0, vals, l, p);
+        System.arraycopy(right, p + 1, vals, l + p, r - 1 - p);
+        return fromMerged(vals, ret);
+      }
+
+      // extract a new right digit from the middle
+      final Item[] last = ((LeafNode) middle.last()).values;
+      final int l = last.length, n = l + r - 1;
+
+      if(l > MIN_LEAF) {
+        // refill from neighbor
+        final int move = (l - MIN_LEAF + 1) / 2;
+        final Item[] newLast = slice(last, 0, l - move);
+        final Item[] newRight = new Item[r - 1 + move];
+        System.arraycopy(last, l - move, newRight, 0, move);
+        System.arraycopy(right, 0, newRight, move, p);
+        System.arraycopy(right, p + 1, newRight, move + p, r - 1 - p);
+        return new BigSeq(left, middle.replaceLast(new LeafNode(newLast)), newRight, ret);
+      }
+
+      // merge last node and digit
+      final Item[] newRight = new Item[n];
+      System.arraycopy(last, 0, newRight, 0, l);
+      System.arraycopy(right, 0, newRight, l, p);
+      System.arraycopy(right, p + 1, newRight, l + p, r - 1 - p);
+      return new BigSeq(left, middle.init(), newRight, ret);
+    }
+
+    // delete in middle tree
+    final TreeSlice<Item, Item> slice = middle.remove(pos - left.length);
+
+    if(slice.isTree()) {
+      // middle tree did not underflow
+      return new BigSeq(left, slice.getTree(), right, ret);
+    }
+
+    // tree height might change
+    final Item[] mid = ((PartialLeafNode) slice.getPartial()).elems;
+    final int l = left.length, m = mid.length, r = right.length;
+
+    if(l > r) {
+      // steal from the bigger digit, in this case left (cannot be minimal)
+      final int move = (l - MIN_DIGIT + 1) / 2;
+      final Item[] newLeft = slice(left, 0, l - move);
+      final Item[] newMid = slice(left, l - move, l + m);
+      System.arraycopy(mid, 0, newMid, move, m);
+      return new BigSeq(newLeft, FingerTree.singleton(new LeafNode(newMid)), right, ret);
+    }
+
+    if(r > MIN_DIGIT) {
+      // steal from right digit
+      final int move = (r - MIN_DIGIT + 1) / 2;
+      final Item[] newMid = slice(mid, 0, m + move);
+      System.arraycopy(right, 0, newMid, m, move);
+      final Item[] newRight = slice(right, move, r);
+      return new BigSeq(left, FingerTree.singleton(new LeafNode(newMid)), newRight, ret);
+    }
+
+    // divide onto left and right digit
+    final int ml = m / 2, mr = m - ml;
+    final Item[] newLeft = slice(left, 0, l + ml);
+    System.arraycopy(mid, 0, newLeft, l, ml);
+    final Item[] newRight = slice(right, -mr, r);
+    System.arraycopy(mid, ml, newRight, 0, mr);
+    final Type rt = ret;
+    return new BigSeq(newLeft, FingerTree.<Item>empty(), newRight, rt);
+  }
+
+  @Override
+  public Value subSeq(final long pos, final long len) {
+    if(pos < 0) throw new IndexOutOfBoundsException("first index < 0: " + pos);
+    if(len < 0) throw new IndexOutOfBoundsException("length < 0: " + len);
+    final long midSize = middle.size();
+    if(len > size - pos)
+      throw new IndexOutOfBoundsException("end out of bounds: " + (pos + len) + " > " + size);
+
+    // the easy cases
+    if(len == 0) return Empty.SEQ;
+    if(len == 1) return itemAt(pos);
+    if(len == size) return this;
+
+    final long end = pos + len;
+    if(end <= left.length) {
+      // completely in left digit
+      final int p = (int) pos, n = (int) len;
+      if(len <= MAX_SMALL) return new SmallSeq(slice(left, p, p + n), ret);
+      final int mid = p + n / 2;
+      final Type rt = ret;
+      return new BigSeq(slice(left, p, mid), FingerTree.<Item>empty(), slice(left, mid, p + n), rt);
+    }
+
+    final long rightOffset = left.length + midSize;
+    if(pos >= rightOffset) {
+      // completely in right digit
+      final int p = (int) (pos - rightOffset), n = (int) len;
+      if(len <= MAX_SMALL) return new SmallSeq(slice(right, p, p + n), ret);
+      final int mid = p + n / 2;
+      final Type rt = ret;
+      return new BigSeq(slice(right, p, mid), FingerTree.<Item>empty(),
+          slice(right, mid, p + n), rt);
+    }
+
+    final int inLeft = pos < left.length ? (int) (left.length - pos) : 0,
+        inRight = end > rightOffset ? (int) (end - rightOffset) : 0;
+    if(inLeft >= MIN_DIGIT && inRight >= MIN_DIGIT) {
+      // digits are still long enough
+      final Item[] newLeft = inLeft == left.length ? left : slice(left, (int) pos, left.length);
+      final Item[] newRight = inRight == right.length ? right : slice(right, 0, inRight);
+      return new BigSeq(newLeft, middle, newRight, ret);
+    }
+
+    if(middle.isEmpty()) {
+      // merge left and right partial digits
+      final Item[] out;
+      if(inLeft == 0) {
+        out = inRight == right.length ? right : slice(right, 0, inRight);
+      } else if(inRight == 0) {
+        out = inLeft == left.length ? left : slice(left, left.length - inLeft, left.length);
+      } else {
+        out = slice(left, left.length - inLeft, left.length + inRight);
+        System.arraycopy(right, 0, out, inLeft, inRight);
+      }
+      return fromMerged(out, ret);
+    }
+
+    final long inMiddle = len - inLeft - inRight;
+    final FingerTree<Item, Item> mid;
+    if(inMiddle == midSize) {
+      mid = middle;
+    } else {
+      // the middle tree must be split
+      final long off = pos < left.length ? 0 : pos - left.length;
+      final TreeSlice<Item, Item> slice = middle.slice(off, inMiddle);
+      // only a partial leaf, merge with digits
+      if(!slice.isTree()) {
+        final Item[] single = ((PartialLeafNode) slice.getPartial()).elems;
+        if(inLeft > 0) {
+          final Item[] out = slice(left, (int) pos, left.length + single.length);
+          System.arraycopy(single, 0, out, inLeft, single.length);
+          return fromMerged(out, ret);
+        }
+        if(inRight > 0) {
+          final Item[] out = slice(single, 0, single.length + inRight);
+          System.arraycopy(right, 0, out, single.length, inRight);
+          return fromMerged(out, ret);
+        }
+        return new SmallSeq(single, ret);
+      }
+
+      mid = slice.getTree();
+    }
+
+    // `mid` is non-empty
+
+    // create a left digit
+    final int off = left.length - inLeft;
+    final Item[] newLeft;
+    final FingerTree<Item, Item> mid1;
+    if(inLeft >= MIN_DIGIT) {
+      newLeft = inLeft == left.length ? left : slice(left, off, left.length);
+      mid1 = mid;
+    } else {
+      final Item[] head = ((LeafNode) mid.head()).values;
+      if(inLeft == 0) {
+        newLeft = head;
+      } else {
+        newLeft = slice(head, -inLeft, head.length);
+        System.arraycopy(left, off, newLeft, 0, inLeft);
+      }
+      mid1 = mid.tail();
+    }
+
+    // create a right digit
+    final Item[] newRight;
+    final FingerTree<Item, Item> newMiddle;
+    if(inRight >= MIN_DIGIT) {
+      newMiddle = mid1;
+      newRight = inRight == right.length ? right : slice(right, 0, inRight);
+    } else if(!mid1.isEmpty()) {
+      final Item[] last = ((LeafNode) mid1.last()).values;
+      newMiddle = mid1.init();
+      if(inRight == 0) {
+        newRight = last;
+      } else {
+        newRight = slice(last, 0, last.length + inRight);
+        System.arraycopy(right, 0, newRight, last.length, inRight);
+      }
+    } else {
+      // not enough elements for a right digit
+      if(inRight == 0) return fromMerged(newLeft, ret);
+      final int n = newLeft.length + inRight;
+      final Item[] out = slice(newLeft, 0, n);
+      System.arraycopy(right, 0, out, newLeft.length, inRight);
+      return fromMerged(out, ret);
+    }
+
+    return new BigSeq(newLeft, newMiddle, newRight, ret);
+  }
+
+  /**
+   * Creates a sequence from two merged, possibly partial digits.
+   * This method requires that the input array's length is not longer than {@code 2 * MAX_DIGIT}.
+   * @param merged the merged digits
+   * @param rt element type
+   * @return the array
+   */
+  private TreeSeq fromMerged(final Item[] merged, final Type rt) {
+    if(merged.length <= MAX_SMALL) return new SmallSeq(merged, rt);
+    final int mid = merged.length / 2;
+    return new BigSeq(slice(merged, 0, mid), FingerTree.<Item>empty(),
+        slice(merged, mid, merged.length), rt);
+  }
+
+  @Override
+  public TreeSeq concat(final TreeSeq seq) {
+    final Type retType = type == seq.type ? type : null;
+    if(seq instanceof SmallSeq) {
+      // merge with right digit
+      final Item[] newRight = concat(right, ((SmallSeq) seq).elems);
+      final int r = newRight.length;
+      if(r <= MAX_DIGIT) return new BigSeq(left, middle, newRight, retType);
+      final int mid = r / 2;
+      final Item[] leaf = slice(newRight, 0, mid);
+      final FingerTree<Item, Item> newMid = middle.snoc(new LeafNode(leaf));
+      return new BigSeq(left, newMid, slice(newRight, mid, r), retType);
+    }
+
+    final BigSeq bigOther = (BigSeq) seq;
+
+    // make nodes out of the digits facing each other
+    final Item[] ls = right, rs = bigOther.left;
+    final int l = ls.length, n = l + rs.length;
+    final int k = (n + MAX_LEAF - 1) / MAX_LEAF, s = (n + k - 1) / k;
+    @SuppressWarnings("unchecked")
+    final Node<Item, Item>[] midNodes = new Node[k];
+    int p = 0;
+    for(int i = 0; i < k; i++) {
+      final int curr = Math.min(n - p, s);
+      final Item[] arr = new Item[curr];
+      for(int j = 0; j < curr; j++, p++) arr[j] = p < l ? ls[p] : rs[p - l];
+      midNodes[i] = new LeafNode(arr);
+    }
+
+    return new BigSeq(left, middle.concat(midNodes, n, bigOther.middle), bigOther.right, retType);
+  }
+
+  @Override
+  public ListIterator<Item> iterator(final long start) {
+    final Item[] ls = left, rs = right;
+    final int l = ls.length , r = rs.length, startPos;
+    final long m = middle.size();
+    final ListIterator<Item> sub;
+    if(start < l) {
+      startPos = (int) start - l;
+      sub = middle.listIterator(0);
+    } else if(start - l < m) {
+      startPos = 0;
+      sub = middle.listIterator(start - l);
+    } else {
+      startPos = (int) (start - l - m) + 1;
+      sub = middle.listIterator(m);
+    }
+
+    return new ListIterator<Item>() {
+      int pos = startPos;
+
+      @Override
+      public int nextIndex() {
+        return pos < 0 ? l + pos
+             : pos > 0 ? (int) (l + m + pos - 1)
+                       : l + sub.nextIndex();
+      }
+
+      @Override
+      public boolean hasNext() {
+        return pos <= r;
+      }
+
+      @Override
+      public Item next() {
+        if(pos > r) throw new NoSuchElementException();
+        if(pos < 0) {
+          // in left digit
+          return ls[l + pos++];
+        }
+
+        if(pos == 0) {
+          // in middle tree
+          if(sub.hasNext()) return sub.next();
+          pos = 1;
+        }
+
+        // in right digit
+        return rs[pos++ - 1];
+      }
+
+      @Override
+      public int previousIndex() {
+        return pos < 0 ? l + pos - 1
+             : pos > 0 ? (int) (l + m + pos - 2)
+                       : l + sub.previousIndex();
+      }
+
+      @Override
+      public boolean hasPrevious() {
+        return pos > -l;
+      }
+
+      @Override
+      public Item previous() {
+        if(pos <= -l) throw new NoSuchElementException();
+        if(pos > 0) {
+          // in right digit
+          if(--pos > 0) return rs[pos - 1];
+        }
+
+        if(pos == 0) {
+          // in middle tree
+          if(sub.hasPrevious()) return sub.previous();
+          pos = -1;
+          return ls[l - 1];
+        }
+
+        // in left digit
+        return ls[l + --pos];
+      }
+
+      @Override
+      public void add(final Item e) {
+        throw new UnsupportedOperationException();
+      }
+
+      @Override
+      public void set(final Item e) {
+        throw new UnsupportedOperationException();
+      }
+
+      @Override
+      public void remove() {
+        throw new UnsupportedOperationException();
+      }
+    };
+  }
+
+  @Override
+  public ValueIter iter() {
+    return new ValueIter() {
+      private long pos;
+      private Iterator<Item> sub;
+
+      @Override
+      public Item next() {
+        if(pos >= size) return null;
+        final long p = pos++;
+        if(p < left.length) return left[(int) p];
+        final long r = size - right.length;
+        if(p >= r) return right[(int) (p - r)];
+        if(sub == null) sub = middle.iterator();
+        return sub.next();
+      }
+
+      @Override
+      public Item get(final long i) {
+        return BigSeq.this.itemAt(i);
+      }
+
+      @Override
+      public long size() {
+        return size;
+      }
+
+      @Override
+      public Value value() {
+        return BigSeq.this;
+      }
+    };
+  }
+
+  @Override
+  void checkInvariants() {
+    final int l = left.length, r = right.length;
+    if(l < MIN_DIGIT || l > MAX_DIGIT) throw new AssertionError("Left digit: " + l);
+    if(r < MIN_DIGIT || r > MAX_DIGIT) throw new AssertionError("Right digit: " + r);
+    middle.checkInvariants();
+  }
+
+  @Override
+  TreeSeq consSmall(final Item[] vals) {
+    final int a = vals.length, b = left.length, n = a + b;
+    if(n <= MAX_DIGIT) {
+      // no need to change the middle tree
+      return new BigSeq(concat(vals, left), middle, right, null);
+    }
+
+    if(a >= MIN_DIGIT && MIN_LEAF <= b && b <= MAX_LEAF) {
+      // reuse the arrays
+      return new BigSeq(vals, middle.cons(new LeafNode(left)), right, null);
+    }
+
+    // left digit is too big
+    final int mid = n / 2, move = mid - a;
+    final Item[] newLeft = slice(vals, 0, mid);
+    System.arraycopy(left, 0, newLeft, a, move);
+    final LeafNode leaf = new LeafNode(slice(left, move, b));
+    return new BigSeq(newLeft, middle.cons(leaf), right, null);
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/tree/LeafNode.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/tree/LeafNode.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/tree/LeafNode.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/tree/LeafNode.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,241 @@
+package org.basex.query.value.seq.tree;
+
+import java.util.*;
+
+import org.basex.query.util.fingertree.*;
+import org.basex.query.value.item.*;
+
+/**
+ * A leaf node containing {@link Item}s.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Leo Woerteler
+ */
+final class LeafNode implements Node<Item, Item> {
+  /** Elements stored in this leaf node. */
+  final Item[] values;
+
+  /**
+   * Constructor.
+   * @param values the values
+   */
+  LeafNode(final Item[] values) {
+    this.values = values;
+    assert values.length >= TreeSeq.MIN_LEAF && values.length <= TreeSeq.MAX_LEAF;
+  }
+
+  @Override
+  public long size() {
+    return values.length;
+  }
+
+  @Override
+  public LeafNode reverse() {
+    final int n = values.length;
+    final Item[] out = new Item[n];
+    for(int i = 0; i < n; i++) out[i] = values[n - 1 - i];
+    return new LeafNode(out);
+  }
+
+  @Override
+  public boolean insert(final Node<Item, Item>[] siblings, final long pos, final Item val) {
+    final int p = (int) pos, n = values.length;
+    final Item[] vals = new Item[n + 1];
+    System.arraycopy(values, 0, vals, 0, p);
+    vals[p] = val;
+    System.arraycopy(values, p, vals, p + 1, n - p);
+
+    if(n < TreeSeq.MAX_LEAF) {
+      // there is capacity
+      siblings[1] = new LeafNode(vals);
+      return false;
+    }
+
+    final LeafNode left = (LeafNode) siblings[0];
+    if(left != null && left.values.length < TreeSeq.MAX_LEAF) {
+      // push elements to the left sibling
+      final Item[] lvals = left.values;
+      final int l = lvals.length, diff = TreeSeq.MAX_LEAF - l, move = (diff + 1) / 2;
+      final Item[] newLeft = new Item[l + move], newRight = new Item[n + 1 - move];
+      System.arraycopy(lvals, 0, newLeft, 0, l);
+      System.arraycopy(vals, 0, newLeft, l, move);
+      System.arraycopy(vals, move, newRight, 0, newRight.length);
+      siblings[0] = new LeafNode(newLeft);
+      siblings[1] = new LeafNode(newRight);
+      return false;
+    }
+
+    final LeafNode right = (LeafNode) siblings[2];
+    if(right != null && right.values.length < TreeSeq.MAX_LEAF) {
+      // push elements to the right sibling
+      final Item[] rvals = right.values;
+      final int r = rvals.length, diff = TreeSeq.MAX_LEAF - r, move = (diff + 1) / 2,
+          l = n + 1 - move;
+      final Item[] newLeft = new Item[l], newRight = new Item[r + move];
+      System.arraycopy(vals, 0, newLeft, 0, l);
+      System.arraycopy(vals, l, newRight, 0, move);
+      System.arraycopy(rvals, 0, newRight, move, r);
+      siblings[1] = new LeafNode(newLeft);
+      siblings[2] = new LeafNode(newRight);
+      return false;
+    }
+
+    // split the node
+    final int l = vals.length / 2, r = vals.length - l;
+    final Item[] newLeft = new Item[l], newRight = new Item[r];
+    System.arraycopy(vals, 0, newLeft, 0, l);
+    System.arraycopy(vals, l, newRight, 0, r);
+    siblings[3] = siblings[2];
+    siblings[1] = new LeafNode(newLeft);
+    siblings[2] = new LeafNode(newRight);
+    return true;
+  }
+
+  @Override
+  public NodeLike<Item, Item>[] remove(final Node<Item, Item> left,
+      final Node<Item, Item> right, final long pos) {
+    final int p = (int) pos, n = values.length;
+    @SuppressWarnings("unchecked")
+    final NodeLike<Item, Item>[] out = new NodeLike[] { left, null, right };
+    if(n > TreeSeq.MIN_LEAF) {
+      // we do not have to split
+      final Item[] vals = new Item[n - 1];
+      System.arraycopy(values, 0, vals, 0, p);
+      System.arraycopy(values, p + 1, vals, p, n - 1 - p);
+      out[1] = new LeafNode(vals);
+      return out;
+    }
+
+    final LeafNode leftLeaf = (LeafNode) left;
+    if(leftLeaf != null && leftLeaf.arity() > TreeSeq.MIN_LEAF) {
+      // steal from the left neighbor
+      final Item[] lvals = leftLeaf.values;
+      final int l = lvals.length, diff = l - TreeSeq.MIN_LEAF, move = (diff + 1) / 2;
+      final int ll = l - move, rl = n - 1 + move;
+      final Item[] newLeft = new Item[ll], newRight = new Item[rl];
+
+      System.arraycopy(lvals, 0, newLeft, 0, ll);
+      System.arraycopy(lvals, ll, newRight, 0, move);
+      System.arraycopy(values, 0, newRight, move, p);
+      System.arraycopy(values, p + 1, newRight, move + p, n - 1 - p);
+      out[0] = new LeafNode(newLeft);
+      out[1] = new LeafNode(newRight);
+      return out;
+    }
+
+    final LeafNode rightLeaf = (LeafNode) right;
+    if(rightLeaf != null && rightLeaf.arity() > TreeSeq.MIN_LEAF) {
+      // steal from the right neighbor
+      final Item[] rvals = rightLeaf.values;
+      final int r = rvals.length, diff = r - TreeSeq.MIN_LEAF, move = (diff + 1) / 2;
+      final int ll = n - 1 + move, rl = r - move;
+      final Item[] newLeft = new Item[ll], newRight = new Item[rl];
+
+      System.arraycopy(values, 0, newLeft, 0, p);
+      System.arraycopy(values, p + 1, newLeft, p, n - 1 - p);
+      System.arraycopy(rvals, 0, newLeft, n - 1, move);
+      System.arraycopy(rvals, move, newRight, 0, rl);
+      out[1] = new LeafNode(newLeft);
+      out[2] = new LeafNode(newRight);
+      return out;
+    }
+
+    if(left != null) {
+      // merge with left neighbor
+      final Item[] lvals = ((LeafNode) left).values;
+      final int l = lvals.length, r = values.length;
+      final Item[] vals = new Item[l + r - 1];
+      System.arraycopy(lvals, 0, vals, 0, l);
+      System.arraycopy(values, 0, vals, l, p);
+      System.arraycopy(values, p + 1, vals, l + p, r - 1 - p);
+      out[0] = new LeafNode(vals);
+      out[1] = null;
+      return out;
+    }
+
+    if(right != null) {
+      // merge with right neighbor
+      final Item[] rvals = ((LeafNode) right).values;
+      final int l = values.length, r = rvals.length;
+      final Item[] vals = new Item[l - 1 + r];
+      System.arraycopy(values, 0, vals, 0, p);
+      System.arraycopy(values, p + 1, vals, p, l - 1 - p);
+      System.arraycopy(rvals, 0, vals, l - 1, r);
+      out[1] = null;
+      out[2] = new LeafNode(vals);
+      return out;
+    }
+
+    // underflow
+    final Item[] vals = new Item[n - 1];
+    System.arraycopy(values, 0, vals, 0, p);
+    System.arraycopy(values, p + 1, vals, p, n - 1 - p);
+    out[1] = new PartialLeafNode(vals);
+    return out;
+  }
+
+  @Override
+  public int append(final NodeLike<Item, Item>[] nodes, final int pos) {
+    if(pos == 0) {
+      nodes[pos] = this;
+      return 1;
+    }
+
+    final NodeLike<Item, Item> left = nodes[pos - 1];
+    if(!(left instanceof PartialLeafNode)) {
+      nodes[pos] = this;
+      return pos + 1;
+    }
+
+    final Item[] ls = ((PartialLeafNode) left).elems, rs = values;
+    final int l = ls.length, r = rs.length, n = l + r;
+    if(n <= TreeSeq.MAX_LEAF) {
+      // merge into one node
+      final Item[] vals = new Item[n];
+      System.arraycopy(ls, 0, vals, 0, l);
+      System.arraycopy(rs, 0, vals, l, r);
+      nodes[pos - 1] = new LeafNode(vals);
+      return pos;
+    }
+
+    // split into two
+    final int ll = n / 2, rl = n - ll, move = r - rl;
+    final Item[] newLeft = new Item[ll], newRight = new Item[rl];
+    System.arraycopy(ls, 0, newLeft, 0, l);
+    System.arraycopy(rs, 0, newLeft, l, move);
+    System.arraycopy(rs, move, newRight, 0, rl);
+    nodes[pos - 1] = new LeafNode(newLeft);
+    nodes[pos] = new LeafNode(newRight);
+    return pos + 1;
+  }
+
+  @Override
+  public NodeLike<Item, Item> slice(final long off, final long size) {
+    final int p = (int) off, n = (int) size;
+    final Item[] out = new Item[n];
+    System.arraycopy(values, p, out, 0, n);
+    return n < TreeSeq.MIN_LEAF ? new PartialLeafNode(out) : new LeafNode(out);
+  }
+
+  @Override
+  public String toString() {
+    return getClass().getSimpleName() + "(" + size() + ")" + Arrays.toString(values);
+  }
+
+  @Override
+  public long checkInvariants() {
+    if(values.length < TreeSeq.MIN_LEAF || values.length > TreeSeq.MAX_LEAF)
+      throw new AssertionError("Wrong " + getClass().getSimpleName() + " size: " + values.length);
+    return values.length;
+  }
+
+  @Override
+  public int arity() {
+    return values.length;
+  }
+
+  @Override
+  public Item getSub(final int index) {
+    return values[index];
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/tree/PartialLeafNode.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/tree/PartialLeafNode.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/tree/PartialLeafNode.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/tree/PartialLeafNode.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,68 @@
+package org.basex.query.value.seq.tree;
+
+import java.util.*;
+
+import org.basex.query.util.fingertree.*;
+import org.basex.query.value.item.*;
+
+/**
+ * A partial leaf node containing fewer elements than required in a node.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Leo Woerteler
+ */
+final class PartialLeafNode implements NodeLike<Item, Item> {
+  /** The single element. */
+  final Item[] elems;
+
+  /**
+   * Constructor.
+   * @param elems the elements
+   */
+  PartialLeafNode(final Item[] elems) {
+    this.elems = elems;
+  }
+
+  @Override
+  public int append(final NodeLike<Item, Item>[] nodes, final int pos) {
+    if(pos == 0) {
+      nodes[0] = this;
+      return 1;
+    }
+
+    final NodeLike<Item, Item> left = nodes[pos - 1];
+    if(left instanceof PartialLeafNode) {
+      final Item[] ls = ((PartialLeafNode) left).elems, rs = elems;
+      final int l = ls.length, r = rs.length, n = l + r;
+      final Item[] vals = new Item[n];
+      System.arraycopy(ls, 0, vals, 0, l);
+      System.arraycopy(rs, 0, vals, l, r);
+      nodes[pos - 1] = n < TreeSeq.MIN_LEAF ? new PartialLeafNode(vals) : new LeafNode(vals);
+      return pos;
+    }
+
+    final Item[] ls = ((LeafNode) left).values, rs = elems;
+    final int l = ls.length, r = rs.length, n = l + r;
+    if(n <= TreeSeq.MAX_LEAF) {
+      final Item[] vals = new Item[n];
+      System.arraycopy(ls, 0, vals, 0, l);
+      System.arraycopy(rs, 0, vals, l, r);
+      nodes[pos - 1] = new LeafNode(vals);
+      return pos;
+    }
+
+    final int ll = n / 2, rl = n - ll, move = l - ll;
+    final Item[] newLeft = new Item[ll], newRight = new Item[rl];
+    System.arraycopy(ls, 0, newLeft, 0, ll);
+    System.arraycopy(ls, ll, newRight, 0, move);
+    System.arraycopy(rs, 0, newRight, move, r);
+    nodes[pos - 1] = new LeafNode(newLeft);
+    nodes[pos] = new LeafNode(newRight);
+    return pos + 1;
+  }
+
+  @Override
+  public String toString() {
+    return getClass().getSimpleName() + "(" + elems.length + ")" + Arrays.toString(elems);
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/tree/SmallSeq.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/tree/SmallSeq.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/tree/SmallSeq.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/tree/SmallSeq.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,203 @@
+package org.basex.query.value.seq.tree;
+
+import java.util.*;
+
+import org.basex.query.iter.*;
+import org.basex.query.util.fingertree.*;
+import org.basex.query.value.*;
+import org.basex.query.value.item.*;
+import org.basex.query.value.seq.*;
+import org.basex.query.value.type.*;
+
+/**
+ * A small sequence that is represented as a single Java array.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Leo Woerteler
+ */
+final class SmallSeq extends TreeSeq {
+  /** The elements. */
+  final Item[] elems;
+
+  /**
+   * Constructor.
+   * @param elems elements
+   * @param ret type of all elements in this sequence
+   */
+  SmallSeq(final Item[] elems, final Type ret) {
+    super(elems.length, ret);
+    this.elems = elems;
+    assert elems.length >= 2 && elems.length <= MAX_SMALL;
+  }
+
+  @Override
+  public Item itemAt(final long index) {
+    // index to small?
+    if(index < 0) throw new IndexOutOfBoundsException("Index < 0: " + index);
+
+    // index too big?
+    if(index >= elems.length) throw new IndexOutOfBoundsException(index + " >= " + elems.length);
+
+    return elems[(int) index];
+  }
+
+  @Override
+  public TreeSeq reverse() {
+    final int n = elems.length;
+    final Item[] es = new Item[n];
+    for(int i = 0; i < n; i++) es[i] = elems[n - 1 - i];
+    return new SmallSeq(es, ret);
+  }
+
+  @Override
+  public TreeSeq insert(final long pos, final Item val) {
+    if(pos < 0) throw new IndexOutOfBoundsException("negative index: " + pos);
+    if(pos > elems.length) throw new IndexOutOfBoundsException("position too big: " + pos);
+
+    final int p = (int) pos, n = elems.length;
+    final Item[] out = new Item[n + 1];
+    System.arraycopy(elems, 0, out, 0, p);
+    out[p] = val;
+    System.arraycopy(elems, p, out, p + 1, n - p);
+
+    if(n < MAX_SMALL) return new SmallSeq(out, null);
+    return new BigSeq(slice(out, 0, MIN_DIGIT), FingerTree.<Item>empty(),
+        slice(out, MIN_DIGIT, n + 1), null);
+  }
+
+  @Override
+  public Value remove(final long pos) {
+    if(pos < 0) throw new IndexOutOfBoundsException("negative index: " + pos);
+    if(pos >= elems.length) throw new IndexOutOfBoundsException("position too big: " + pos);
+    final int p = (int) pos, n = elems.length;
+    if(n == 2) return elems[pos == 0 ? 1 : 0];
+
+    final Item[] out = new Item[n - 1];
+    System.arraycopy(elems, 0, out, 0, p);
+    System.arraycopy(elems, p + 1, out, p, n - 1 - p);
+    return new SmallSeq(out, ret);
+  }
+
+  @Override
+  public Value subSeq(final long pos, final long len) {
+    if(pos < 0) throw new IndexOutOfBoundsException("first index < 0: " + pos);
+    if(len < 0) throw new IndexOutOfBoundsException("length < 0: " + len);
+    if(pos + len > elems.length)
+      throw new IndexOutOfBoundsException("end out of bounds: "
+          + (pos + len) + " > " + elems.length);
+
+    final int p = (int) pos, n = (int) len;
+    return n == 0 ? Empty.SEQ : n == 1 ? elems[p] : new SmallSeq(slice(elems, p, p + n), ret);
+  }
+
+  @Override
+  public TreeSeq concat(final TreeSeq other) {
+    return other.consSmall(elems);
+  }
+
+  @Override
+  public ListIterator<Item> iterator(final long start) {
+    return new ListIterator<Item>() {
+      private int index = (int) start;
+
+      @Override
+      public int nextIndex() {
+        return index;
+      }
+
+      @Override
+      public boolean hasNext() {
+        return index < elems.length;
+      }
+
+      @Override
+      public Item next() {
+        if(index >= elems.length) throw new NoSuchElementException();
+        return elems[index++];
+      }
+
+      @Override
+      public int previousIndex() {
+        return index - 1;
+      }
+
+      @Override
+      public boolean hasPrevious() {
+        return index > 0;
+      }
+
+      @Override
+      public Item previous() {
+        if(index <= 0) throw new NoSuchElementException();
+        return elems[--index];
+      }
+
+      @Override
+      public void set(final Item e) {
+        throw new UnsupportedOperationException();
+      }
+
+      @Override
+      public void add(final Item e) {
+        throw new UnsupportedOperationException();
+      }
+
+      @Override
+      public void remove() {
+        throw new UnsupportedOperationException();
+      }
+    };
+  }
+
+  @Override
+  public ValueIter iter() {
+    return new ValueIter() {
+      private int pos;
+
+      @Override
+      public Item next() {
+        return pos < size ? elems[pos++] : null;
+      }
+
+      @Override
+      public Item get(final long i) {
+        return elems[(int) i];
+      }
+
+      @Override
+      public long size() {
+        return size;
+      }
+
+      @Override
+      public Value value() {
+        return SmallSeq.this;
+      }
+    };
+  }
+
+  @Override
+  void checkInvariants() {
+    final int n = elems.length;
+    if(n == 0) throw new AssertionError("Empty array in " + getClass().getSimpleName());
+    if(n == 1) throw new AssertionError("Singleton array in " + getClass().getSimpleName());
+    if(n > MAX_SMALL) throw new AssertionError("Array too big: " + n);
+  }
+
+  @Override
+  TreeSeq consSmall(final Item[] left) {
+    final int l = left.length, r = elems.length, n = l + r;
+    if(Math.min(l, r) >= MIN_DIGIT) {
+      // both arrays can be used as digits
+      return new BigSeq(left, FingerTree.<Item>empty(), elems, null);
+    }
+
+    final Item[] out = new Item[n];
+    System.arraycopy(left, 0, out, 0, l);
+    System.arraycopy(elems, 0, out, l, r);
+    if(n <= MAX_SMALL) return new SmallSeq(out, null);
+
+    final int mid = n / 2;
+    return new BigSeq(slice(out, 0, mid), FingerTree.<Item>empty(), slice(out, mid, n), null);
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/tree/TreeSeqBuilder.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/tree/TreeSeqBuilder.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/tree/TreeSeqBuilder.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/tree/TreeSeqBuilder.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,292 @@
+package org.basex.query.value.seq.tree;
+
+import java.util.*;
+
+import org.basex.query.util.fingertree.*;
+import org.basex.query.value.*;
+import org.basex.query.value.item.*;
+import org.basex.query.value.seq.*;
+import org.basex.query.value.type.*;
+
+/**
+ * A builder for creating a {@link Seq}uence (with at least 2 items) by prepending and appending
+ * {@link Item}s.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Leo Woerteler
+ */
+public final class TreeSeqBuilder implements Iterable<Item> {
+  /** Capacity of the root. */
+  private static final int CAP = 2 * TreeSeq.MAX_DIGIT;
+  /** Size of inner nodes. */
+  private static final int NODE_SIZE = (TreeSeq.MIN_LEAF + TreeSeq.MAX_LEAF + 1) / 2;
+
+  /** Ring buffer containing the root-level elements. */
+  private final Item[] vals = new Item[CAP];
+
+  /** Number of elements in left digit. */
+  private int inLeft;
+  /** Middle between left and right digit in the buffer. */
+  private int mid = CAP / 2;
+  /** Number of elements in right digit. */
+  private int inRight;
+  /** Builder for the middle tree. */
+  private final FingerTreeBuilder<Item> tree = new FingerTreeBuilder<>();
+
+  /**
+   * Returns a {@link Value} representation of the given items.
+   * @param items array containing the items
+   * @param n number of items (must be {@code 2} or more)
+   * @param type item type of the resulting value (not checked), may be {@code null}
+   * @return the value
+   */
+  public static Seq value(final Item[] items, final int n, final Type type) {
+    if(n < 2) throw new AssertionError("At least 2 items expected");
+
+    if(n <= TreeSeq.MAX_SMALL) {
+      final Item[] small = new Item[n];
+      System.arraycopy(items, 0, small, 0, n);
+      return new SmallSeq(small, type);
+    }
+
+    final TreeSeqBuilder tsb = new TreeSeqBuilder();
+    for(int i = 0; i < n; i++) tsb.add(items[i]);
+    return tsb.seq(type);
+  }
+
+  /**
+   * Adds an element to the start of the array.
+   * @param elem element to add
+   * @return reference to this builder for convenience
+   */
+  public TreeSeqBuilder addFront(final Item elem) {
+    if(inLeft < TreeSeq.MAX_DIGIT) {
+      // just insert the element
+      vals[(mid - inLeft + CAP - 1) % CAP] = elem;
+      inLeft++;
+    } else if(tree.isEmpty() && inRight < TreeSeq.MAX_DIGIT) {
+      // move the middle to the left
+      mid = (mid + CAP - 1) % CAP;
+      vals[(mid - inLeft + CAP) % CAP] = elem;
+      inRight++;
+    } else {
+      // push leaf node into the tree
+      tree.prepend(new LeafNode(items(mid - NODE_SIZE, NODE_SIZE)));
+
+      // move rest of the nodes to the right
+      final int rest = inLeft - NODE_SIZE;
+      final int p0 = (mid - inLeft + CAP) % CAP;
+      for(int i = 0; i < rest; i++) {
+        final int from = (p0 + i) % CAP, to = (from + NODE_SIZE) % CAP;
+        vals[to] = vals[from];
+      }
+
+      // insert the element
+      vals[(mid - rest + CAP - 1) % CAP] = elem;
+      inLeft = rest + 1;
+    }
+    return this;
+  }
+
+  /**
+   * Adds an element to the end of the array.
+   * @param elem element to add
+   * @return reference to this builder for convenience
+   */
+  public TreeSeqBuilder add(final Item elem) {
+    if(inRight < TreeSeq.MAX_DIGIT) {
+      // just insert the element
+      vals[(mid + inRight) % CAP] = elem;
+      inRight++;
+    } else if(tree.isEmpty() && inLeft < TreeSeq.MAX_DIGIT) {
+      // move the middle to the right
+      mid = (mid + 1) % CAP;
+      vals[(mid + inRight + CAP - 1) % CAP] = elem;
+      inLeft++;
+    } else {
+      // push leaf node into the tree
+      tree.append(new LeafNode(items(mid, NODE_SIZE)));
+
+      // move rest of the nodes to the right
+      final int rest = inRight - NODE_SIZE;
+      for(int i = 0; i < rest; i++) {
+        final int to = (mid + i) % CAP, from = (to + NODE_SIZE) % CAP;
+        vals[to] = vals[from];
+      }
+
+      // insert the element
+      vals[(mid + rest) % CAP] = elem;
+      inRight = rest + 1;
+    }
+    return this;
+  }
+
+  /**
+   * Appends the items of the given value to this builder.
+   * @param val value to append
+   * @return this builder for convenience
+   */
+  public TreeSeqBuilder add(final Value val) {
+    // shortcut for adding single items
+    if(val instanceof Item) return add((Item) val);
+
+    if(!(val instanceof BigSeq)) {
+      for(final Item it : val) add(it);
+      return this;
+    }
+
+    final BigSeq big = (BigSeq) val;
+    final Item[] ls = big.left, rs = big.right;
+    final FingerTree<Item, Item> midTree = big.middle;
+    if(midTree.isEmpty()) {
+      for(final Item l : ls) add(l);
+      for(final Item r : rs) add(r);
+      return this;
+    }
+
+    // merge middle digits
+    if(tree.isEmpty()) {
+      final int k = inLeft + inRight;
+      final Item[] temp = new Item[k];
+      final int l = (mid - inLeft + CAP) % CAP, m = CAP - l;
+      if(k <= m) {
+        System.arraycopy(vals, l, temp, 0, k);
+      } else {
+        System.arraycopy(vals, l, temp, 0, m);
+        System.arraycopy(vals, 0, temp, m, k - m);
+      }
+
+      inLeft = inRight = 0;
+      tree.append(midTree);
+      for(int i = ls.length; --i >= 0;) addFront(ls[i]);
+      for(int i = k; --i >= 0;) addFront(temp[i]);
+      for(int i = 0; i < rs.length; i++) add(rs[i]);
+      return this;
+    }
+
+    final int inMiddle = inRight + ls.length,
+        leaves = (inMiddle + TreeSeq.MAX_LEAF - 1) / TreeSeq.MAX_LEAF,
+        leafSize = (inMiddle + leaves - 1) / leaves;
+    for(int i = 0, l = 0; l < leaves; l++) {
+      final int inLeaf = Math.min(leafSize, inMiddle - i);
+      final Item[] leaf = new Item[inLeaf];
+      for(int p = 0; p < inLeaf; p++) {
+        leaf[p] = i < inRight ? vals[(mid + i) % CAP] : ls[i - inRight];
+        i++;
+      }
+      tree.append(new LeafNode(leaf));
+    }
+
+    tree.append(midTree);
+    inRight = 0;
+    for(final Item r : rs) add(r);
+    return this;
+  }
+
+  /**
+   * Creates a sequence containing the current elements of this builder.
+   * @return resulting sequence
+   */
+  Seq seq() {
+    return seq((Type) null);
+  }
+
+  /**
+   * Creates a sequence containing the current elements of this builder.
+   * @param ret type of all elements, may be {@code null}
+   * @return resulting sequence
+   */
+  public Seq seq(final Type ret) {
+    final int n = inLeft + inRight;
+    final int start = (mid - inLeft + CAP) % CAP;
+    if(n < 2) throw new AssertionError("At least 2 items expected");
+
+    // small int array, fill directly
+    if(n <= TreeSeq.MAX_SMALL) return new SmallSeq(items(start, n), ret);
+
+    // deep array
+    final int ll = tree.isEmpty() ? n / 2 : inLeft;
+    return new BigSeq(items(start, ll), tree.freeze(), items(start + ll, n - ll), ret);
+  }
+
+  @Override
+  public String toString() {
+    final StringBuilder sb = new StringBuilder(getClass().getSimpleName()).append('[');
+    if(tree.isEmpty()) {
+      final int n = inLeft + inRight, first = (mid - inLeft + CAP) % CAP;
+      if(n > 0) {
+        sb.append(vals[first]);
+        for(int i = 1; i < n; i++) sb.append(", ").append(vals[(first + i) % CAP]);
+      }
+    } else {
+      final int first = (mid - inLeft + CAP) % CAP;
+      sb.append(vals[first]);
+      for(int i = 1; i < inLeft; i++) sb.append(", ").append(vals[(first + i) % CAP]);
+      for(final Item item : tree) sb.append(", ").append(item);
+      for(int i = 0; i < inRight; i++) sb.append(", ").append(vals[(mid + i) % CAP]);
+    }
+    return sb.append(']').toString();
+  }
+
+  @Override
+  public Iterator<Item> iterator() {
+
+    return new Iterator<Item>() {
+      private int pos = -inLeft;
+      private Iterator<Item> sub;
+
+      @Override
+      public boolean hasNext() {
+        return pos <= inRight;
+      }
+
+      @Override
+      public Item next() {
+        if(pos > inRight) throw new NoSuchElementException();
+
+        if(pos < 0) {
+          final int p = pos++;
+          return vals[(mid + p + CAP) % CAP];
+        }
+
+        if(pos == 0) {
+          if(tree != null) {
+            if(sub == null) sub = tree.iterator();
+            if(sub.hasNext()) return sub.next();
+            sub = null;
+          }
+          pos++;
+        }
+
+        // pos > 0
+        final int p = pos++;
+        return vals[(mid + p - 1) % CAP];
+      }
+
+      @Override
+      public void remove() {
+        throw new UnsupportedOperationException();
+      }
+    };
+  }
+
+  /**
+   * Returns an array containing the given number of items starting at the given position in this
+   * builder's ring buffer.
+   * @param from position of the first item
+   * @param n number of items
+   * @return array containing the items
+   */
+  private Item[] items(final int from, final int n) {
+    final Item[] arr = new Item[n];
+    final int p = ((from % CAP) + CAP) % CAP;
+    final int m = CAP - p;
+    if(n <= m) {
+      System.arraycopy(vals, p, arr, 0, n);
+    } else {
+      System.arraycopy(vals, p, arr, 0, m);
+      System.arraycopy(vals, 0, arr, m, n - m);
+    }
+    return arr;
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/tree/TreeSeq.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/tree/TreeSeq.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/seq/tree/TreeSeq.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/seq/tree/TreeSeq.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,249 @@
+package org.basex.query.value.seq.tree;
+
+import static org.basex.query.QueryError.*;
+import static org.basex.query.QueryText.*;
+
+import java.util.*;
+
+import org.basex.query.*;
+import org.basex.query.iter.*;
+import org.basex.query.value.*;
+import org.basex.query.value.item.*;
+import org.basex.query.value.node.*;
+import org.basex.query.value.seq.*;
+import org.basex.query.value.type.*;
+import org.basex.query.value.type.SeqType.Occ;
+import org.basex.util.*;
+
+/**
+ * A tree storing {@link Item}s.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Leo Woerteler
+ */
+public abstract class TreeSeq extends Seq {
+  /** Minimum size of a leaf. */
+  static final int MIN_LEAF = 8;
+  /** Maximum size of a leaf. */
+  static final int MAX_LEAF = 2 * MIN_LEAF - 1;
+  /** Minimum number of elements in a digit. */
+  static final int MIN_DIGIT = MIN_LEAF / 2;
+  /** Maximum number of elements in a digit. */
+  static final int MAX_DIGIT = MAX_LEAF + MIN_DIGIT;
+  /** Maximum size of a small array. */
+  static final int MAX_SMALL = 2 * MIN_DIGIT - 1;
+
+  /** Item Types. */
+  Type ret;
+
+  /**
+   * Default constructor.
+   * @param size number of elements in this sequence
+   * @param ret type of all items in this sequence
+   */
+  TreeSeq(final long size, final Type ret) {
+    super(size, ret == null ? AtomType.ITEM : ret);
+    this.ret = ret;
+  }
+
+  @Override
+  public final Value insertBefore(final long pos, final Value val) {
+    final long n = val.size();
+    if(n == 0) return this;
+    if(n == 1) return insert(pos, (Item) val);
+
+    final long l = pos, r = size - pos;
+    if(val instanceof TreeSeq && (l == 0 || r == 0)) {
+      final TreeSeq other = (TreeSeq) val;
+      return l == 0 ? other.concat(this) : concat(other);
+    }
+
+    final TreeSeqBuilder tsb = new TreeSeqBuilder();
+    if(l < MAX_SMALL) {
+      tsb.add(val);
+      for(long i = l; --i >= 0;) tsb.addFront(itemAt(i));
+    } else {
+      tsb.add(subSeq(0, l));
+      tsb.add(val);
+    }
+
+    if(r < MAX_SMALL) {
+      for(long i = size - r; i < size; i++) tsb.add(itemAt(i));
+    } else {
+      tsb.add(subSeq(pos, r));
+    }
+
+    return tsb.seq();
+  }
+
+  /**
+   * Concatenates this sequence with another one.
+   * Running time: <i>O(log (min { this.size(), other.size() }))</i>
+   * @param other array to append to the end of this array
+   * @return resulting array
+   */
+  public abstract TreeSeq concat(final TreeSeq other);
+
+  /**
+   * Iterator over the members of this sequence.
+   * @param start starting position
+   *   (i.e. the position initially returned by {@link ListIterator#nextIndex()})
+   * @return array over the array members
+   */
+  public abstract ListIterator<Item> iterator(final long start);
+
+  @Override
+  public final Iterator<Item> iterator() {
+    return iterator(0);
+  }
+
+  @Override
+  public final Object[] toJava() throws QueryException {
+    final ArrayList<Object> obj = new ArrayList<>((int) size);
+    for(final Item it : this) obj.add(it.toJava());
+    return obj.toArray();
+  }
+
+  @Override
+  public final void plan(final FElem plan) {
+    final FElem el = planElem(SIZE, size);
+    addPlan(plan, el);
+    for(int v = 0; v != Math.min(size, 5); ++v) itemAt(v).plan(el);
+  }
+
+  @Override
+  public final String toString() {
+    return toString(false);
+  }
+
+  /**
+   * Returns a string representation of the sequence.
+   * @param error error flag
+   * @return string
+   */
+  private String toString(final boolean error) {
+    final StringBuilder sb = new StringBuilder(PAREN1);
+    for(int i = 0; i < size; ++i) {
+      sb.append(i == 0 ? "" : SEP);
+      final Item it = itemAt(i);
+      sb.append(error ? it.toErrorString() : it.toString());
+      if(sb.length() <= 16 || i + 1 == size) continue;
+      // output is chopped to prevent too long error strings
+      sb.append(SEP).append(DOTS);
+      break;
+    }
+    return sb.append(PAREN2).toString();
+  }
+
+  @Override
+  public abstract ValueIter iter();
+
+  @Override
+  public final Seq materialize(final InputInfo ii) throws QueryException {
+    final TreeSeqBuilder tsb = new TreeSeqBuilder();
+    for(final Item it : this) tsb.add(it.materialize(ii));
+    return tsb.seq();
+  }
+
+  @Override
+  public final Seq atomValue(final InputInfo ii) throws QueryException {
+    final TreeSeqBuilder tsb = new TreeSeqBuilder();
+    for(final Item it : this) tsb.add(it.atomValue(ii));
+    return tsb.seq();
+  }
+
+  @Override
+  public final long atomSize() {
+    long s = 0;
+    for(final Item it : this) s += it.atomSize();
+    return s;
+  }
+
+  @Override
+  public final int writeTo(final Item[] arr, final int off) {
+    final int n = (int) Math.min(arr.length - off, size());
+    final Iterator<Item> iter = iterator();
+    for(int i = 0; i < n; i++) arr[off + i] = iter.next();
+    return n;
+  }
+
+  @Override
+  public final boolean homogeneous() {
+    return ret != null && ret != AtomType.ITEM;
+  }
+
+  @Override
+  public final boolean iterable() {
+    return false;
+  }
+
+  @Override
+  public final Item ebv(final QueryContext qc, final InputInfo ii) throws QueryException {
+    final Item head = itemAt(0);
+    if(head instanceof ANode) return head;
+    throw EBV_X.get(ii, this);
+  }
+
+  @Override
+  public final SeqType seqType() {
+    if(ret == null) {
+      final Iterator<Item> iter = iterator();
+      Type t = iter.next().type;
+      while(iter.hasNext()) {
+        if(t != iter.next().type) {
+          t = AtomType.ITEM;
+          break;
+        }
+      }
+      ret = t;
+      type = t;
+    }
+    return SeqType.get(ret, Occ.ONE_MORE);
+  }
+
+  /**
+   * Prepends the given elements to this sequence.
+   * @param vals values, with length at most {@link TreeSeq#MAX_SMALL}
+   * @return resulting sequence
+   */
+  abstract TreeSeq consSmall(final Item[] vals);
+
+  /**
+   * Returns items containing the values at the indices {@code from} to {@code to - 1} in
+   * the given sequence. Its length is always {@code to - from}. If {@code from} is smaller than
+   * zero, the first {@code -from} entries in the resulting sequence are {@code null}.
+   * If {@code to > arr.length} then the last {@code to - arr.length} entries are {@code null}.
+   * If {@code from == 0 && to == arr.length}, the original items are returned.
+   * @param items input sequence
+   * @param from first index, inclusive (may be negative)
+   * @param to last index, exclusive (may be greater than {@code arr.length})
+   * @return resulting items
+   */
+  static final Item[] slice(final Item[] items, final int from, final int to) {
+    final Item[] out = new Item[to - from];
+    final int in0 = Math.max(0, from), in1 = Math.min(to, items.length);
+    final int out0 = Math.max(-from, 0);
+    System.arraycopy(items, in0, out, out0, in1 - in0);
+    return out;
+  }
+
+  /**
+   * Concatenates the two item arrays.
+   * @param as first array
+   * @param bs second array
+   * @return resulting array
+   */
+  static final Item[] concat(final Item[] as, final Item[] bs) {
+    final int l = as.length, r = bs.length, n = l + r;
+    final Item[] out = new Item[n];
+    System.arraycopy(as, 0, out, 0, l);
+    System.arraycopy(bs, 0, out, l, r);
+    return out;
+  }
+
+  /**
+   * Checks that this array's implementation does not violate any invariants.
+   * @throws AssertionError if an invariant was violated
+   */
+  abstract void checkInvariants();
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/type/ListType.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/type/ListType.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/type/ListType.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/type/ListType.java	2015-07-14 10:54:40.000000000 +0000
@@ -4,7 +4,6 @@
 import static org.basex.util.Token.*;
 
 import org.basex.query.*;
-import org.basex.query.iter.*;
 import org.basex.query.util.*;
 import org.basex.query.value.*;
 import org.basex.query.value.item.*;
@@ -76,7 +75,7 @@
       final InputInfo ii) throws QueryException {
 
     final byte[][] values = split(normalize(item.string(ii)), ' ');
-    final ValueBuilder vb = new ValueBuilder(values.length);
+    final ValueBuilder vb = new ValueBuilder();
     for(final byte[] v : values) vb.add(type.cast(Str.get(v), qc, sc, ii));
     return vb.value();
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/type/SeqType.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/type/SeqType.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/type/SeqType.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/type/SeqType.java	2015-07-14 10:54:40.000000000 +0000
@@ -5,7 +5,7 @@
 
 import org.basex.query.*;
 import org.basex.query.expr.path.*;
-import org.basex.query.iter.*;
+import org.basex.query.util.list.*;
 import org.basex.query.value.*;
 import org.basex.query.value.array.Array;
 import org.basex.query.value.item.*;
@@ -397,8 +397,8 @@
     if(val.isEmpty()) return Empty.SEQ;
     if(val instanceof Item) return cast((Item) val, qc, sc, ii, true);
 
-    final ValueBuilder vb = new ValueBuilder((int) vs);
-    for(int v = 0; v < vs; v++) vb.add(cast(val.itemAt(v), qc, sc, ii, true));
+    final ValueBuilder vb = new ValueBuilder();
+    for(final Item it : val) vb.add(cast(it, qc, sc, ii, true));
     return vb.value();
   }
 
@@ -443,21 +443,21 @@
 
     if(n == 0) return Empty.SEQ;
 
-    ValueBuilder vb = null;
+    ItemList buffer = null;
     for(int i = 0; i < n; i++) {
       final Item it = value.itemAt(i);
       if(instance(it, true)) {
         if(i == 0 && value.homogeneous()) return value;
-        if(vb != null) vb.add(it);
+        if(buffer != null) buffer.add(it);
       } else {
-        if(vb == null) {
-          vb = new ValueBuilder(new Item[n], 0);
-          for(int j = 0; j < i; j++) vb.add(value.itemAt(j));
+        if(buffer == null) {
+          buffer = new ItemList(n);
+          for(int j = 0; j < i; j++) buffer.add(value.itemAt(j));
         }
-        promote(qc, sc, ii, it, opt, vb);
+        promote(qc, sc, ii, it, opt, buffer);
       }
     }
-    return vb != null ? Seq.get(vb.items(), (int) vb.size(), type) : value;
+    return buffer != null ? buffer.value(type) : value;
   }
 
   /**
@@ -467,32 +467,32 @@
    * @param ii input info
    * @param item item to promote
    * @param opt if the result should be optimized
-   * @param vb value builder
+   * @param buffer value builder
    * @throws QueryException query exception
    */
   public void promote(final QueryContext qc, final StaticContext sc, final InputInfo ii,
-      final Item item, final boolean opt, final ValueBuilder vb) throws QueryException {
+      final Item item, final boolean opt, final ItemList buffer) throws QueryException {
 
     if(type instanceof AtomType) {
       for(final Item atom : item.atomValue(ii)) {
         final Type tp = atom.type;
         if(tp.instanceOf(type)) {
-          vb.add(atom);
+          buffer.add(atom);
         } else if(tp == AtomType.ATM) {
           if(type.nsSensitive()) throw NSSENS_X_X.get(ii, item.type, type);
-          vb.add(type.cast(atom, qc, sc, ii));
+          for(final Item it : type.cast(atom, qc, sc, ii)) buffer.add(it);
         } else if(type == AtomType.DBL && (tp == AtomType.FLT || tp.instanceOf(AtomType.DEC))) {
-          vb.add(Dbl.get(atom.dbl(ii)));
+          buffer.add(Dbl.get(atom.dbl(ii)));
         } else if(type == AtomType.FLT && tp.instanceOf(AtomType.DEC)) {
-          vb.add(Flt.get(atom.flt(ii)));
+          buffer.add(Flt.get(atom.flt(ii)));
         } else if(type == AtomType.STR && atom instanceof Uri) {
-          vb.add(Str.get(atom.string(ii)));
+          buffer.add(Str.get(atom.string(ii)));
         } else {
           throw INVPROMOTE_X_X_X.get(ii, item.seqType(), withOcc(Occ.ONE), item);
         }
       }
     } else if(item instanceof FItem && type instanceof FuncType) {
-      vb.add(((FItem) item).coerceTo((FuncType) type, qc, ii, opt));
+      buffer.add(((FItem) item).coerceTo((FuncType) type, qc, ii, opt));
     } else {
       throw INVPROMOTE_X_X_X.get(ii, item.seqType(), withOcc(Occ.ONE), item);
     }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/ValueBuilder.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/ValueBuilder.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/ValueBuilder.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/ValueBuilder.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,126 @@
+package org.basex.query.value;
+
+import java.util.*;
+
+import org.basex.query.value.item.*;
+import org.basex.query.value.seq.*;
+import org.basex.query.value.seq.tree.*;
+import org.basex.query.value.type.*;
+
+/**
+ * A builder for efficiently creating a {@link Value} by prepending and appending
+ * {@link Item}s and {@link Value}s.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Leo Woerteler
+ */
+public final class ValueBuilder {
+  /** The first added value is cached. */
+  private Value firstValue;
+  /** Underlying sequence builder, only instantiated if there are at least two items. */
+  private TreeSeqBuilder builder;
+
+  /**
+   * Concatenates two values.
+   * @param v1 first value to concatenate
+   * @param v2 second value to concatenate
+   * @return value which contains all items of {@code v1} followed by all items of {@code v2}
+   */
+  public static Value concat(final Value v1, final Value v2) {
+    final long s1 = v1.size();
+    if(s1 == 0) return v2;
+    final long s2 = v2.size();
+    if(s2 == 0) return v1;
+    if(s1 > 1) return ((Seq) v1).insertBefore(s1, v2);
+    if(s2 > 1) return ((Seq) v2).insert(0, (Item) v1);
+    return TreeSeqBuilder.value(new Item[] { (Item) v1, (Item) v2 }, 2, null);
+  }
+
+  /**
+   * Returns a {@link Value} representation of the given items.
+   * @param items array containing the items
+   * @param n number of items
+   * @param type item type of the resulting value (not checked), may be {@code null}
+   * @return the value
+   */
+  public static Value value(final Item[] items, final int n, final Type type) {
+    return n == 0 ? Empty.SEQ : n == 1 ? items[0] : TreeSeqBuilder.value(items, n, type);
+  }
+
+  /**
+   * Adds an item to the front of the built value.
+   * @param item item to add
+   * @return reference to this builder for convenience
+   */
+  public ValueBuilder addFront(final Item item) {
+    final TreeSeqBuilder tree = builder;
+    if(tree != null) {
+      tree.addFront(item);
+    } else {
+      final Value first = firstValue;
+      if(first != null) {
+        builder = new TreeSeqBuilder().add(first).addFront(item);
+        firstValue = null;
+      } else {
+        firstValue = item;
+      }
+    }
+    return this;
+  }
+
+  /**
+   * Appends a value to the end of the built value.
+   * @param value value to append
+   * @return reference to this builder for convenience
+   */
+  public ValueBuilder add(final Value value) {
+    if(value.isEmpty()) return this;
+
+    final TreeSeqBuilder tree = builder;
+    if(tree != null) {
+      tree.add(value);
+    } else {
+      final Value first = firstValue;
+      if(first != null) {
+        builder = new TreeSeqBuilder().add(first).add(value);
+        firstValue = null;
+      } else {
+        firstValue = value;
+      }
+    }
+    return this;
+  }
+
+  /**
+   * Returns a {@link Value} representation of the items currently stored in this builder.
+   * @return contents of this builder
+   */
+  public Value value() {
+    return value(null);
+  }
+
+  /**
+   * Returns a {@link Value} representation of the items currently stored in this builder
+   * annotated with the given item type.
+   * @param type item type, may be {@code null}
+   * @return contents of this builder
+   */
+  public Value value(final Type type) {
+    final Value first = firstValue;
+    if(first != null) return first;
+    final TreeSeqBuilder tree = builder;
+    return tree != null ? tree.seq(type) : Empty.SEQ;
+  }
+
+  @Override
+  public String toString() {
+    final StringBuilder sb = new StringBuilder(getClass().getSimpleName()).append('[');
+    final Iterator<Item> iter = firstValue != null ? firstValue.iterator() :
+      builder != null ? builder.iterator() : Collections.<Item>emptyIterator();
+    if(iter.hasNext()) {
+      sb.append(iter.next());
+      while(iter.hasNext()) sb.append(", ").append(iter.next());
+    }
+    return sb.append(']').toString();
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/query/value/Value.java basex-8.2.3/basex-core/src/main/java/org/basex/query/value/Value.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/query/value/Value.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/query/value/Value.java	2015-07-14 10:54:40.000000000 +0000
@@ -13,6 +13,7 @@
 import org.basex.query.expr.*;
 import org.basex.query.iter.*;
 import org.basex.query.util.*;
+import org.basex.query.util.list.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.type.*;
 import org.basex.query.var.*;
@@ -56,7 +57,7 @@
   }
 
   @Override
-  public final Iterator<Item> iterator() {
+  public Iterator<Item> iterator() {
     return iter().iterator();
   }
 
@@ -72,6 +73,20 @@
   }
 
   /**
+   * Returns a sub-sequence of this value with the given start and length.<br>
+   * The following properties must hold:
+   * <ul>
+   *   <li>{@code start >= 0},
+   *   <li>{@code len >= 0},
+   *   <li>{@code start + len <= size()}
+   * </ul>
+   * @param start starting position (zero-based)
+   * @param len number of items
+   * @return the sub-sequence
+   */
+  public abstract Value subSeq(final long start, final long len);
+
+  /**
    * Materializes streamable values, or returns a self reference.
    * @param ii input info
    * @return materialized item
@@ -159,14 +174,14 @@
   public abstract int writeTo(final Item[] arr, final int index);
 
   /**
-   * Creates an {@link ValueBuilder}, containing all items of this value.
+   * Creates an array containing all items of this value.
    * Use with care, as compressed Values are expanded, creating many objects.
    * @return cached items
    */
-  public final ValueBuilder cache() {
-    final ValueBuilder vb = new ValueBuilder((int) size());
-    vb.size(writeTo(vb.items(), 0));
-    return vb;
+  public final ItemList cache() {
+    final long n = size();
+    if(n > Integer.MAX_VALUE) throw Util.notExpected(n);
+    return new ItemList((int) n).add(this);
   }
 
   /**
@@ -176,7 +191,7 @@
    * @throws QueryIOException query I/O exception
    */
   public final ArrayOutput serialize() throws QueryIOException {
-    return serialize(null);
+    return serialize((SerializerOptions) null);
   }
 
   /**
@@ -188,9 +203,7 @@
   public final ArrayOutput serialize(final SerializerOptions options) throws QueryIOException {
     final ArrayOutput ao = new ArrayOutput();
     try {
-      try(final Serializer ser = Serializer.get(ao, options)) {
-        for(final Item it : this) ser.serialize(it);
-      }
+      serialize(Serializer.get(ao, options));
     } catch(final QueryIOException ex) {
       throw ex;
     } catch(final IOException ex) {
@@ -200,7 +213,20 @@
   }
 
   /**
+   * Serializes the value with the specified serializer.
+   * @param ser serializer
+   * @throws IOException I/O exception
+   */
+  public final void serialize(final Serializer ser) throws IOException {
+    for(final Item it : this) {
+      if(ser.finished()) break;
+      ser.serialize(it);
+    }
+  }
+
+  /**
    * Gets the item at the given position in the value.
+   * The specified value must be lie within the valid bounds.
    * @param pos position
    * @return item
    */
@@ -212,6 +238,12 @@
    */
   public abstract boolean homogeneous();
 
+  /**
+   * Returns a sequence in reverse order.
+   * @return sequence
+   */
+  public abstract Value reverse();
+
   @Override
   public boolean accept(final ASTVisitor visitor) {
     final Data data = data();
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/server/ClientListener.java basex-8.2.3/basex-core/src/main/java/org/basex/server/ClientListener.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/server/ClientListener.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/server/ClientListener.java	2015-07-14 10:54:40.000000000 +0000
@@ -42,12 +42,6 @@
   /** Socket reference. */
   private final Socket socket;
 
-  /** Socket for events. */
-  private Socket esocket;
-  /** Output for events. */
-  private PrintOutput eout;
-  /** Flag for active events. */
-  private boolean events;
   /** Input stream. */
   private BufferInput in;
   /** Output stream. */
@@ -98,10 +92,6 @@
             create();
           } else if(sc == ServerCmd.ADD) {
             add();
-          } else if(sc == ServerCmd.WATCH) {
-            watch();
-          } else if(sc == ServerCmd.UNWATCH) {
-            unwatch();
           } else if(sc == ServerCmd.REPLACE) {
             replace();
           } else if(sc == ServerCmd.STORE) {
@@ -247,11 +237,6 @@
     try {
       new Close().run(context);
       socket.close();
-      if(events) {
-        esocket.close();
-        // remove this session from all events in pool
-        for(final Sessions s : context.events.values()) s.remove(this);
-      }
     } catch(final Throwable ex) {
       log(LogType.ERROR, Util.message(ex));
       Util.stack(ex);
@@ -267,33 +252,6 @@
   }
 
   /**
-   * Registers the event socket.
-   * @param s socket
-   * @throws IOException I/O exception
-   */
-  public synchronized void register(final Socket s) throws IOException {
-    esocket = s;
-    eout = PrintOutput.get(s.getOutputStream());
-    eout.write(0);
-    eout.flush();
-  }
-
-  /**
-   * Sends a notification to the client.
-   * @param name event name
-   * @param msg event message
-   * @throws IOException I/O exception
-   */
-  public synchronized void notify(final byte[] name, final byte[] msg) throws IOException {
-    last = System.currentTimeMillis();
-    eout.print(name);
-    eout.write(0);
-    eout.print(msg);
-    eout.write(0);
-    eout.flush();
-  }
-
-  /**
    * Returns the host and port of a client.
    * @return string representation
    */
@@ -394,59 +352,6 @@
   }
 
   /**
-   * Watches an event.
-   * @throws IOException I/O exception
-   */
-  private void watch() throws IOException {
-    server.initEvents();
-
-    // initialize server-based event handling
-    if(!events) {
-      out.print(Integer.toString(context.soptions.get(StaticOptions.EVENTPORT)));
-      out.write(0);
-      out.print(Long.toString(getId()));
-      out.write(0);
-      out.flush();
-      events = true;
-    }
-    final String name = in.readString();
-    final Sessions session = context.events.get(name);
-    final boolean ok = session != null && !session.contains(this);
-    final String message;
-    if(ok) {
-      session.add(this);
-      message = WATCHING_EVENT_X;
-    } else if(session == null) {
-      message = EVENT_UNKNOWN_X;
-    } else {
-      message = EVENT_WATCHED_X;
-    }
-    info(Util.info(message, name), ok);
-  }
-
-  /**
-   * Unwatches an event.
-   * @throws IOException I/O exception
-   */
-  private void unwatch() throws IOException {
-    final String name = in.readString();
-
-    final Sessions session = context.events.get(name);
-    final boolean ok = session != null && session.contains(this);
-    final String message;
-    if(ok) {
-      session.remove(this);
-      message = UNWATCHING_EVENT_X;
-    } else if(session == null) {
-      message = EVENT_UNKNOWN_X;
-    } else {
-      message = EVENT_NOT_WATCHED_X;
-    }
-    info(Util.info(message, name), ok);
-    out.flush();
-  }
-
-  /**
    * Processes the query iterator.
    * @param sc server command
    * @throws IOException I/O exception
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/server/EventNotifier.java basex-8.2.3/basex-core/src/main/java/org/basex/server/EventNotifier.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/server/EventNotifier.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/server/EventNotifier.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,15 +0,0 @@
-package org.basex.server;
-
-/**
- * Notification interface for handling database events.
- *
- * @author BaseX Team 2005-15, BSD License
- * @author Roman Raedle
- */
-public interface EventNotifier {
-  /**
-   * Invoked when a database event was fired.
-   * @param value event string
-   */
-  void notify(final String value);
-}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/server/Log.java basex-8.2.3/basex-core/src/main/java/org/basex/server/Log.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/server/Log.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/server/Log.java	2015-07-14 10:54:40.000000000 +0000
@@ -97,7 +97,7 @@
    * @param info info string (can be {@code null})
    * @param perf performance string
    */
-  private synchronized void write(final String address, final User user, final String type,
+  public synchronized void write(final String address, final User user, final String type,
       final String info, final Performance perf) {
 
     if(!sopts.get(StaticOptions.LOG)) {
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/server/ServerCmd.java basex-8.2.3/basex-core/src/main/java/org/basex/server/ServerCmd.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/server/ServerCmd.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/server/ServerCmd.java	2015-07-14 10:54:40.000000000 +0000
@@ -27,10 +27,6 @@
   CREATE(8),
   /** Code for adding a document to a database: {path}0{input}0. */
   ADD(9),
-  /** Code for watching an event: {name}0. */
-  WATCH(10),
-  /** Code for unwatching an event: {name}0. */
-  UNWATCH(11),
   /** Code for replacing a document in a database: {path}0{input}0. */
   REPLACE(12),
   /** Code for storing raw data in a database: {path}0{input}0. */
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/server/ServerQuery.java basex-8.2.3/basex-core/src/main/java/org/basex/server/ServerQuery.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/server/ServerQuery.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/server/ServerQuery.java	2015-07-14 10:54:40.000000000 +0000
@@ -30,8 +30,6 @@
 
   /** Query processor. */
   private QueryProcessor qp;
-  /** Serialization parameters. */
-  private SerializerOptions parameters;
   /** Parsing flag. */
   private boolean parsed;
   /** Query info. */
@@ -91,8 +89,7 @@
    * @throws IOException I/O Exception
    */
   public String parameters() throws IOException {
-    if(parameters == null) parameters = parse().qc.serParams();
-    return parameters.toString();
+    return parse().qc.serParams().toString();
   }
 
   /**
@@ -125,12 +122,11 @@
       qi.compiling = perf.time();
       final Iter ir = qp.iter();
       qi.evaluating = perf.time();
-      parameters();
 
       // iterate through results
       int c = 0;
       final PrintOutput po = PrintOutput.get(encode ? new EncodingOutput(out) : out);
-      try(final Serializer ser = Serializer.get(po, full ? null : parameters)) {
+      try(final Serializer ser = Serializer.get(po, full ? null : qp.qc.serParams())) {
         for(Item it; (it = ir.next()) != null;) {
           if(iter) {
             po.write(full ? it.xdmInfo() : it.typeId().bytes());
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/util/Array.java basex-8.2.3/basex-core/src/main/java/org/basex/util/Array.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/util/Array.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/util/Array.java	2015-07-14 10:54:40.000000000 +0000
@@ -132,7 +132,7 @@
   }
 
   /**
-   * Sorts the specified tokens and returns an integer array with offsets to the sorted tokens.
+   * Sorts the specified tokens and returns an array with offsets to the sorted array.
    * @param values values to sort by
    * @param numeric numeric sort
    * @param ascending ascending
@@ -146,7 +146,7 @@
   }
 
   /**
-   * Sorts the specified doubles and returns an integer array with offsets to the sorted doubles.
+   * Sorts the specified double values and returns an array with offsets to the sorted array.
    * @param values values to sort by
    * @param ascending ascending
    * @return array containing the order
@@ -158,7 +158,7 @@
   }
 
   /**
-   * Sorts the specified integers and returns an integer array with offsets to the sorted integers.
+   * Sorts the specified int values and returns an array with offsets to the sorted array.
    * @param values values to sort by
    * @param ascending ascending
    * @return array containing the order
@@ -167,6 +167,18 @@
     final IntList il = number(values.length);
     il.sort(values, ascending);
     return il.finish();
+  }
+
+  /**
+   * Sorts the specified long values and returns an array with offsets to the sorted array.
+   * @param values values to sort by
+   * @param ascending ascending
+   * @return array containing the order
+   */
+  public static int[] createOrder(final long[] values, final boolean ascending) {
+    final IntList il = number(values.length);
+    il.sort(values, ascending);
+    return il.finish();
   }
 
   /**
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/util/Atts.java basex-8.2.3/basex-core/src/main/java/org/basex/util/Atts.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/util/Atts.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/util/Atts.java	2015-07-14 10:54:40.000000000 +0000
@@ -3,16 +3,16 @@
 import org.basex.util.list.*;
 
 /**
- * This is a simple container for attributes (name/value pairs).
+ * Resizable-array implementation for attributes (name/value pairs).
  *
  * @author BaseX Team 2005-15, BSD License
  * @author Christian Gruen
  */
 public final class Atts extends ElementList {
   /** Name array. */
-  private byte[][] nm = new byte[1][];
+  private byte[][] nm;
   /** Value array. */
-  private byte[][] vl = new byte[1][];
+  private byte[][] vl;
 
   /**
    * Default constructor.
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/util/DateTime.java basex-8.2.3/basex-core/src/main/java/org/basex/util/DateTime.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/util/DateTime.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/util/DateTime.java	2015-07-14 10:54:40.000000000 +0000
@@ -4,19 +4,16 @@
 import java.util.*;
 
 /**
- * This class contains static, thread-safe methods for parsing and formatting
- * dates and times.
+ * This class contains static, thread-safe methods for parsing and formatting dates and times.
  *
  * @author BaseX Team 2005-15, BSD License
  * @author Christian Gruen
  */
 public final class DateTime {
-  /** Date pattern. */
-  public static final String PATTERN = "-\\d{4}-\\d{2}-\\d{2}-\\d{2}-\\d{2}-\\d{2}";
+  /** Date format without milliseconds and timestamp (uses UTC time zone). */
+  public static final SimpleDateFormat DATETIME = new SimpleDateFormat("yyyy-MM-dd-HH-mm-ss");
   /** Full date format. */
   public static final SimpleDateFormat FULL = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'");
-  /** Date format without milliseconds and timestamp. */
-  public static final SimpleDateFormat DATETIME = new SimpleDateFormat("yyyy-MM-dd-HH-mm-ss");
   /** Date format. */
   public static final SimpleDateFormat DATE = new SimpleDateFormat("yyyy-MM-dd");
   /** Time format. */
@@ -30,39 +27,36 @@
   private DateTime() { }
 
   /**
-   * Parses the specified date and returns its time in milliseconds.
-   * Returns {@code null} if it cannot be converted.
-   * @param date date to be parsed
-   * @return time in milliseconds
+   * Parses a string and produces a date object.
+   * Returns the standard base time if it cannot be converted.
+   * @param date string representing a date
+   * @return parsed date
    */
-  public static long parse(final String date) {
+  public static synchronized Date parse(final String date) {
     try {
-      synchronized(FULL) { return parse(date, FULL).getTime(); }
+      return (date.contains(":") ? FULL : DATETIME).parse(date);
     } catch(final ParseException ex) {
       Util.errln(ex);
-      return 0;
+      return new Date(0);
     }
   }
 
   /**
-   * Thread-safe method to create a string from a given date in a given format.
-   * @param format date format
+   * Creates a full string representation for the specified date.
    * @param date date
    * @return string with the formatted date
    */
-  public static synchronized String format(final Date date, final DateFormat format) {
-    return format.format(date);
+  public static String format(final Date date) {
+    return FULL.format(date);
   }
 
   /**
-   * Thread-safe method to parse a date from a string in a given format.
-   * @param date string representing a date
+   * Creates a string representation for a date in the specified format.
    * @param format date format
-   * @return parsed date
-   * @throws ParseException if the string cannot be parsed
+   * @param date date
+   * @return string with the formatted date
    */
-  public static synchronized Date parse(final String date, final DateFormat format)
-      throws ParseException {
-    return format.parse(date);
+  public static synchronized String format(final Date date, final DateFormat format) {
+    return format.format(date);
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/util/FreeSlots.java basex-8.2.3/basex-core/src/main/java/org/basex/util/FreeSlots.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/util/FreeSlots.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/util/FreeSlots.java	2015-07-14 10:54:40.000000000 +0000
@@ -3,15 +3,19 @@
 import java.util.*;
 import java.util.Map.Entry;
 
+import org.basex.util.list.*;
+
 /**
- * Organizes free slots for heap files.
+ * Organizes free slots in heap files.
  *
  * @author BaseX Team 2005-15, BSD License
  * @author Christian Gruen
  */
 public final class FreeSlots {
   /** Free slots: byte sizes referencing file offsets. */
-  private final TreeMap<Integer, LinkedList<Long>> free = new TreeMap<>();
+  private final TreeMap<Integer, LongList> free = new TreeMap<>();
+  /** Number of slots. */
+  private int slots;
 
   /**
    * Adds a value for the specified slot size.
@@ -19,40 +23,105 @@
    * @param offset file offset
    */
   public void add(final int size, final long offset) {
-    LinkedList<Long> ll = free.get(size);
-    if(ll == null) {
-      ll = new LinkedList<>();
-      free.put(size, ll);
-    }
-    ll.add(offset);
+    add(size, offset, true);
   }
 
   /**
    * Returns the offset of a slot that is greater than or equal to the specified size.
-   * @param size ideal byte size
+   * @param size ideal (minimum) slot size
    * @param offset offset used as fallback if no free slot is available
    * @return insertion offset
    */
   public long get(final int size, final long offset) {
-    Long off = null;
-    final Entry<Integer, LinkedList<Long>> entry = free.ceilingEntry(size);
+    long off = -1;
+    final Entry<Integer, LongList> entry = free.ceilingEntry(size);
     if(entry != null) {
       final int slotSize = entry.getKey();
-      final LinkedList<Long> offsets = entry.getValue();
+      if(slotSize < size) throw Util.notExpected("Free slot is too small: % < %", slotSize, size);
+
+      final LongList offsets = entry.getValue();
       off = offsets.pop();
+      slots--;
       if(offsets.isEmpty()) free.remove(slotSize);
-      // add new slow entry if chosen entry is smaller than supplied size
-      if(slotSize < size) throw Util.notExpected("Free slot is too small: % < %", slotSize, size);
-      if(slotSize > size) add(size - slotSize, off + slotSize);
+
+      if(slotSize > size) {
+        if(off + slotSize > offset)
+          throw Util.notExpected("Free slot exceeds file offset: % + % > %", off, slotSize, offset);
+        // chosen entry is smaller than supplied size: add entry for remaining free slot
+        add(slotSize - size, off + size);
+      }
+    }
+    return off == -1 ? offset : off;
+  }
+
+  /**
+   * Adds a value for the specified slot size.
+   * @param size byte size
+   * @param offset file offset
+   * @param opt optimize
+   */
+  private void add(final int size, final long offset, final boolean opt) {
+    LongList ll = free.get(size);
+    if(ll == null) {
+      ll = new LongList();
+      free.put(size, ll);
+    }
+    ll.add(offset);
+    slots++;
+    if(opt) optimize();
+  }
+
+  /**
+   * Optimizes the free slot list structure by merging adjacent entries.
+   * Currently, this function is called after every addition of a new slot value.
+   */
+  private void optimize() {
+    if(free.isEmpty()) return;
+
+    // sort all entries by their offset (use native arrays; faster than TreeMap)
+    final int size = slots;
+    final LongList offList = new LongList(size);
+    final IntList sizeList = new IntList(size);
+    for(final Entry<Integer, LongList> entry : free.entrySet()) {
+      final int slotSize = entry.getKey();
+      final LongList list = entry.getValue();
+      final int ll = list.size();
+      for(int l = 0; l < ll; l++) {
+        offList.add(list.get(l));
+        sizeList.add(slotSize);
+      }
+    }
+    if(size != offList.size())
+      throw Util.notExpected("Wrong slot count: % vs. %", size, offList.size());
+
+    final long[] offsets = offList.finish();
+    final int[] slotSizes = sizeList.finish();
+    final int[] index = Array.createOrder(offsets, true);
+
+    // rebuild map with merged slots
+    free.clear();
+    slots = 0;
+    long offset = offsets[0];
+    int slotSize = slotSizes[index[0]];
+    for(int c = 1; c < size; c++) {
+      final long o = offsets[c];
+      final int s = slotSizes[index[c]];
+      if(o == offset + slotSize) {
+        slotSize += s;
+      } else {
+        add(slotSize, offset, false);
+        offset = o;
+        slotSize = s;
+      }
     }
-    return off == null ? offset : off;
+    add(slotSize, offset, false);
   }
 
   @Override
   public String toString() {
-    final StringBuilder sb = new StringBuilder(free.size() + " entries:\n");
-    for(final Entry<Integer, LinkedList<Long>> entry : free.entrySet()) {
-      sb.append("- ").append(entry.getKey()).append(": ").append(entry.getValue()).append('\n');
+    final StringBuilder sb = new StringBuilder("FREE SLOTS: " + free.size() + "\n");
+    for(final Entry<Integer, LongList> entry : free.entrySet()) {
+      sb.append("  ").append(entry.getKey()).append(": ").append(entry.getValue()).append('\n');
     }
     return sb.toString();
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/util/ft/GermanStemmer.java basex-8.2.3/basex-core/src/main/java/org/basex/util/ft/GermanStemmer.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/util/ft/GermanStemmer.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/util/ft/GermanStemmer.java	2015-07-14 10:54:40.000000000 +0000
@@ -131,7 +131,7 @@
       strip(tb);
     }
     tl = tb.size();
-    if(tb.get(tl - 1) == 'z') tb.set(tl - 1, (byte) 'x');
+    if(tl > 0 && tb.get(tl - 1) == 'z') tb.set(tl - 1, (byte) 'x');
     return tb;
   }
 
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/util/hash/TokenSet.java basex-8.2.3/basex-core/src/main/java/org/basex/util/hash/TokenSet.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/util/hash/TokenSet.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/util/hash/TokenSet.java	2015-07-14 10:54:40.000000000 +0000
@@ -133,7 +133,7 @@
    * The deletion of keys will lead to empty entries. If {@link #size} is called after
    * deletions, the original number of entries will be returned.
    * @param key key
-   * @return deleted key or 0
+   * @return id of the deleted key, or {@code 0} if the key did not exist
    */
   public int delete(final byte[] key) {
     final int b = Token.hash(key) & buckets.length - 1;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/util/http/HttpClient.java basex-8.2.3/basex-core/src/main/java/org/basex/util/http/HttpClient.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/util/http/HttpClient.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/util/http/HttpClient.java	2015-07-14 10:54:40.000000000 +0000
@@ -19,6 +19,7 @@
 import org.basex.io.serial.*;
 import org.basex.query.*;
 import org.basex.query.iter.*;
+import org.basex.query.util.list.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.node.*;
 import org.basex.util.*;
@@ -55,7 +56,7 @@
    * @return HTTP response
    * @throws QueryException query exception
    */
-  public ValueIter sendRequest(final byte[] href, final ANode request, final ValueBuilder bodies)
+  public Iter sendRequest(final byte[] href, final ANode request, final Iter bodies)
       throws QueryException {
 
     final HttpRequest req = new HttpRequestParser(info).parse(request, bodies);
@@ -75,7 +76,7 @@
         setRequestContent(conn.getOutputStream(), req);
       }
 
-      return new HttpResponse(info, options).getResponse(conn, body, mediaType);
+      return new HttpResponse(info, options).getResponse(conn, body, mediaType).iter();
 
     } catch(final IOException ex) {
       throw HC_ERROR_X.get(info, ex);
@@ -248,8 +249,8 @@
    * @param out output stream
    * @throws IOException I/O exception
    */
-  private static void writePayload(final ValueBuilder payload,
-      final HashMap<String, String> atts, final OutputStream out) throws IOException {
+  private static void writePayload(final ItemList payload, final HashMap<String, String> atts,
+      final OutputStream out) throws IOException {
 
     // detect method (specified by @method or derived from @media-type)
     String method = atts.get(SerializerOptions.METHOD.name());
@@ -278,8 +279,8 @@
       if(Strings.eq(method, BINARY)) {
         out.write(io.read());
       } else {
-        final ValueBuilder vb = new ValueBuilder().add(Str.get(new TextInput(io).content()));
-        write(vb, atts, method, out);
+        final ItemList buffer = new ItemList().add(Str.get(new TextInput(io).content()));
+        write(buffer, atts, method, out);
       }
     }
   }
@@ -292,7 +293,7 @@
    * @param out connection output stream
    * @throws IOException I/O Exception
    */
-  private static void write(final ValueBuilder payload, final HashMap<String, String> attrs,
+  private static void write(final ItemList payload, final HashMap<String, String> attrs,
       final String method, final OutputStream out) throws IOException {
 
     // extract serialization parameters
@@ -305,7 +306,7 @@
 
     // serialize items according to the parameters
     try(final Serializer ser = Serializer.get(out, sopts)) {
-      payload.serialize(ser);
+      for(final Item it : payload) ser.serialize(it);
     }
   }
 
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/util/http/HttpPayload.java basex-8.2.3/basex-core/src/main/java/org/basex/util/http/HttpPayload.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/util/http/HttpPayload.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/util/http/HttpPayload.java	2015-07-14 10:54:40.000000000 +0000
@@ -16,7 +16,6 @@
 import org.basex.io.in.*;
 import org.basex.io.serial.*;
 import org.basex.query.*;
-import org.basex.query.iter.*;
 import org.basex.query.util.list.*;
 import org.basex.query.value.*;
 import org.basex.query.value.item.*;
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/util/http/HttpRequest.java basex-8.2.3/basex-core/src/main/java/org/basex/util/http/HttpRequest.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/util/http/HttpRequest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/util/http/HttpRequest.java	2015-07-14 10:54:40.000000000 +0000
@@ -3,7 +3,7 @@
 import java.util.*;
 
 import org.basex.core.StaticOptions.AuthMethod;
-import org.basex.query.iter.*;
+import org.basex.query.util.list.*;
 import org.basex.util.http.HttpText.*;
 
 /**
@@ -20,7 +20,7 @@
   /** Body or multipart attributes. */
   public final HashMap<String, String> payloadAttrs = new HashMap<>();
   /** Body content. */
-  public final ValueBuilder bodyContent = new ValueBuilder();
+  public final ItemList bodyContent = new ItemList();
   /** Parts in case of multipart request. */
   public final ArrayList<Part> parts = new ArrayList<>();
   /** Indicator for multipart request. */
@@ -49,6 +49,6 @@
     /** Attributes of part body. */
     public final HashMap<String, String> bodyAttrs = new HashMap<>();
     /** Content of part body. */
-    public final ValueBuilder bodyContent = new ValueBuilder();
+    public final ItemList bodyContent = new ItemList();
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/util/http/HttpRequestParser.java basex-8.2.3/basex-core/src/main/java/org/basex/util/http/HttpRequestParser.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/util/http/HttpRequestParser.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/util/http/HttpRequestParser.java	2015-07-14 10:54:40.000000000 +0000
@@ -10,6 +10,7 @@
 import org.basex.io.serial.*;
 import org.basex.query.*;
 import org.basex.query.iter.*;
+import org.basex.query.util.list.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.node.*;
 import org.basex.util.*;
@@ -40,7 +41,7 @@
    * @return parsed request
    * @throws QueryException query exception
    */
-  public HttpRequest parse(final ANode request, final ValueBuilder bodies) throws QueryException {
+  public HttpRequest parse(final ANode request, final Iter bodies) throws QueryException {
     final HttpRequest req = new HttpRequest();
 
     if(request != null) {
@@ -94,7 +95,7 @@
    * @param hdrs map for parsed headers
    * @return body or multipart
    */
-  private static ANode parseHdrs(final AxisIter iter, final HashMap<String, String> hdrs) {
+  private static ANode parseHdrs(final BasicNodeIter iter, final HashMap<String, String> hdrs) {
     for(final ANode node : iter) {
       final QNm nm = node.qname();
       if(nm == null) continue;
@@ -122,7 +123,7 @@
    * @throws QueryException query exception
    */
   private void parseBody(final ANode body, final Item contItem, final HashMap<String, String> attrs,
-      final ValueBuilder bodyContent) throws QueryException {
+      final ItemList bodyContent) throws QueryException {
 
     parseAttrs(body, attrs);
     checkBody(body, attrs);
@@ -147,14 +148,14 @@
    * @param parts list for multipart parts
    * @throws QueryException query exception
    */
-  private void parseMultipart(final ANode multipart, final ValueBuilder contItems,
+  private void parseMultipart(final ANode multipart, final Iter contItems,
       final HashMap<String, String> attrs, final ArrayList<Part> parts) throws QueryException {
 
     parseAttrs(multipart, attrs);
     if(attrs.get(SerializerOptions.MEDIA_TYPE.name()) == null)
       throw HC_REQ_X.get(info, "Attribute media-type of http:multipart is mandatory");
 
-    final AxisIter prts = multipart.children();
+    final BasicNodeIter prts = multipart.children();
     while(true) {
       final Part p = new Part();
       final ANode partBody = parseHdrs(prts, p.headers);
@@ -224,7 +225,7 @@
 
     // if src attribute is used to set the content of the body, no
     // other attributes must be specified and no content must be present
-    if(bodyAttrs.get(SRC) != null && (bodyAttrs.size() > 2 || body.children().more()))
+    if(bodyAttrs.get(SRC) != null && (bodyAttrs.size() > 2 || body.children().next() != null))
       throw HC_ATTR.get(info);
 
   }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/util/http/HttpResponse.java basex-8.2.3/basex-core/src/main/java/org/basex/util/http/HttpResponse.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/util/http/HttpResponse.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/util/http/HttpResponse.java	2015-07-14 10:54:40.000000000 +0000
@@ -8,7 +8,7 @@
 
 import org.basex.core.*;
 import org.basex.query.*;
-import org.basex.query.iter.*;
+import org.basex.query.util.list.*;
 import org.basex.query.value.node.*;
 import org.basex.util.*;
 
@@ -45,24 +45,26 @@
    * @throws QueryException query exception
    */
   @SuppressWarnings("resource")
-  public ValueIter getResponse(final HttpURLConnection conn, final boolean body, final String mtype)
+  public ItemList getResponse(final HttpURLConnection conn, final boolean body, final String mtype)
       throws IOException, QueryException {
 
     // check content type
-    InputStream is = conn.getErrorStream();
-    final boolean error = is != null;
+    boolean error = false;
+    InputStream is = null;
     try {
-      if(!error) is = conn.getInputStream();
+      is = conn.getInputStream();
     } catch(final IOException ex) {
       Util.debug(ex);
+      is = conn.getErrorStream();
+      error = true;
     }
 
     // result
-    final ValueBuilder vb = new ValueBuilder();
+    final ItemList res = new ItemList();
 
     // construct <http:response/>
     final FElem response = new FElem(Q_RESPONSE).declareNS();
-    vb.add(response);
+    res.add(response);
 
     final String msg = conn.getResponseMessage();
     response.add(STATUS, token(conn.getResponseCode()));
@@ -85,11 +87,11 @@
         final MediaType type = error || mtype == null ? ctype == null ? MediaType.TEXT_PLAIN :
           new MediaType(ctype) : new MediaType(mtype);
         response.add(hp.parse(type));
-        if(body) vb.add(hp.payloads());
+        if(body) res.add(hp.payloads());
       } finally {
         is.close();
       }
     }
-    return vb;
+    return res;
   }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/util/http/HttpText.java basex-8.2.3/basex-core/src/main/java/org/basex/util/http/HttpText.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/util/http/HttpText.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/util/http/HttpText.java	2015-07-14 10:54:40.000000000 +0000
@@ -20,6 +20,8 @@
   String AUTHORIZATION = "Authorization";
   /** HTTP header: Content-Type. */
   String CONTENT_TYPE = "Content-Type";
+  /** HTTP header: Location. */
+  String LOCATION = "Location";
   /** HTTP header: Accept. */
   String ACCEPT = "Accept";
 
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/util/list/BoolList.java basex-8.2.3/basex-core/src/main/java/org/basex/util/list/BoolList.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/util/list/BoolList.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/util/list/BoolList.java	2015-07-14 10:54:40.000000000 +0000
@@ -5,7 +5,7 @@
 import org.basex.util.*;
 
 /**
- * This is a simple container for native booleans.
+ * Resizable-array implementation for native booleans.
  *
  * @author BaseX Team 2005-15, BSD License
  * @author Christian Gruen
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/util/list/ByteList.java basex-8.2.3/basex-core/src/main/java/org/basex/util/list/ByteList.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/util/list/ByteList.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/util/list/ByteList.java	2015-07-14 10:54:40.000000000 +0000
@@ -7,7 +7,7 @@
 import org.basex.util.*;
 
 /**
- * This is a simple container for byte values.
+ * Resizable-array implementation for native bytes.
  *
  * @author BaseX Team 2005-15, BSD License
  * @author Christian Gruen
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/util/list/ElementList.java basex-8.2.3/basex-core/src/main/java/org/basex/util/list/ElementList.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/util/list/ElementList.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/util/list/ElementList.java	2015-07-14 10:54:40.000000000 +0000
@@ -11,7 +11,7 @@
  */
 public abstract class ElementList {
   /** Resize factor for extending the arrays. */
-  double factor = Array.RESIZE;
+  protected double factor = Array.RESIZE;
   /** Number of elements. */
   protected int size;
 
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/util/list/IntList.java basex-8.2.3/basex-core/src/main/java/org/basex/util/list/IntList.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/util/list/IntList.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/util/list/IntList.java	2015-07-14 10:54:40.000000000 +0000
@@ -5,7 +5,7 @@
 import org.basex.util.*;
 
 /**
- * This is a simple container for native integers.
+ * Resizable-array implementation for native int values.
  *
  * @author BaseX Team 2005-15, BSD License
  * @author Christian Gruen
@@ -113,14 +113,14 @@
   /**
    * Inserts elements at the specified index position.
    * @param index inserting position
-   * @param element elements to be inserted
+   * @param elements elements to be inserted
    */
-  public final void insert(final int index, final int[] element) {
-    final int l = element.length;
+  public final void insert(final int index, final int... elements) {
+    final int l = elements.length;
     if(l == 0) return;
     if(size + l > list.length) list = Arrays.copyOf(list, newSize(size + l));
     Array.move(list, index, l, size - index);
-    System.arraycopy(element, 0, list, index, l);
+    System.arraycopy(elements, 0, list, index, l);
     size += l;
   }
 
@@ -284,12 +284,23 @@
   }
 
   /**
+   * Sorts the data in the order of the specified numeric array.
+   * Note that the input array will be resorted as well.
+   * The algorithm is derived from {@link Arrays#sort(int[])}.
+   * @param num token array to sort by
+   * @param asc ascending
+   */
+  public final void sort(final long[] num, final boolean asc) {
+    sort(0, size, asc, num);
+  }
+
+  /**
    * Sorts the array.
    * @param s offset
    * @param e length
    * @param g numeric sort
    * @param f ascending/descending sort
-   * @param t sort tokens
+   * @param t sort array
    */
   private void sort(final int s, final int e, final boolean g, final boolean f, final byte[][] t) {
     if(e < 7) {
@@ -350,7 +361,7 @@
    * @param s offset
    * @param e length
    * @param f ascending/descending sort
-   * @param t sort tokens
+   * @param t sort array
    */
   private void sort(final int s, final int e, final boolean f, final double[] t) {
     if(e < 7) {
@@ -411,7 +422,7 @@
    * @param s offset
    * @param e length
    * @param f ascending/descending sort
-   * @param t sort tokens
+   * @param t sort array
    */
   private void sort(final int s, final int e, final boolean f, final int[] t) {
     if(e < 7) {
@@ -468,6 +479,67 @@
   }
 
   /**
+   * Sorts the array.
+   * @param s offset
+   * @param e length
+   * @param f ascending/descending sort
+   * @param t sort array
+   */
+  private void sort(final int s, final int e, final boolean f, final long[] t) {
+    if(e < 7) {
+      for(int i = s; i < e + s; ++i) {
+        for(int j = i; j > s; j--) {
+          final long h = t[j - 1] - t[j];
+          if(f ? h < 0 : h > 0) break;
+          s(j, j - 1, t);
+        }
+      }
+      return;
+    }
+
+    int m = s + (e >> 1);
+    if(e > 7) {
+      int l = s;
+      int n = s + e - 1;
+      if(e > 40) {
+        final int k = e >>> 3;
+        l = m(l, l + k, l + (k << 1));
+        m = m(m - k, m, m + k);
+        n = m(n - (k << 1), n - k, n);
+      }
+      m = m(l, m, n);
+    }
+    final long v = t[m];
+
+    int a = s, b = a, c = s + e - 1, d = c;
+    while(true) {
+      while(b <= c) {
+        final long h = t[b] - v;
+        if(f ? h > 0 : h < 0) break;
+        if(h == 0) s(a++, b, t);
+        ++b;
+      }
+      while(c >= b) {
+        final long h = t[c] - v;
+        if(f ? h < 0 : h > 0) break;
+        if(h == 0) s(c, d--, t);
+        --c;
+      }
+      if(b > c) break;
+      s(b++, c--, t);
+    }
+
+    final int n = s + e;
+    int k = Math.min(a - s, b - a);
+    s(s, b - k, k, t);
+    k = Math.min(d - c, n - d - 1);
+    s(b, n - k, k, t);
+
+    if((k = b - a) > 1) sort(s, k, f, t);
+    if((k = d - c) > 1) sort(n - k, k, f, t);
+  }
+
+  /**
    * Compares two numeric tokens and returns an integer.
    * @param a first token
    * @param b second token
@@ -492,7 +564,7 @@
    * Swaps two array elements.
    * @param a first offset
    * @param b second offset
-   * @param t sort tokens
+   * @param t sort array
    */
   private void s(final int a, final int b, final byte[][] t) {
     final int l = list[a];
@@ -507,7 +579,7 @@
    * Swaps two array elements.
    * @param a first offset
    * @param b second offset
-   * @param t sort tokens
+   * @param t sort array
    */
   private void s(final int a, final int b, final double[] t) {
     final int l = list[a];
@@ -522,7 +594,7 @@
    * Swaps two array elements.
    * @param a first offset
    * @param b second offset
-   * @param t sort tokens
+   * @param t sort array
    */
   private void s(final int a, final int b, final int[] t) {
     final int l = list[a];
@@ -534,11 +606,26 @@
   }
 
   /**
+   * Swaps two array elements.
+   * @param a first offset
+   * @param b second offset
+   * @param t sort array
+   */
+  private void s(final int a, final int b, final long[] t) {
+    final int l = list[a];
+    list[a] = list[b];
+    list[b] = l;
+    final long c = t[a];
+    t[a] = t[b];
+    t[b] = c;
+  }
+
+  /**
    * Swaps x[a .. (a+n-1)] with x[b .. (b+n-1)].
    * @param a first offset
    * @param b second offset
    * @param n number of elements
-   * @param t sort tokens
+   * @param t sort array
    */
   private void s(final int a, final int b, final int n, final byte[][] t) {
     for(int i = 0; i < n; ++i) s(a + i, b + i, t);
@@ -549,7 +636,7 @@
    * @param a first offset
    * @param b second offset
    * @param n number of elements
-   * @param t sort tokens
+   * @param t sort array
    */
   private void s(final int a, final int b, final int n, final double[] t) {
     for(int i = 0; i < n; ++i) s(a + i, b + i, t);
@@ -560,12 +647,23 @@
    * @param a first offset
    * @param b second offset
    * @param n number of elements
-   * @param t sort tokens
+   * @param t sort array
    */
   private void s(final int a, final int b, final int n, final int[] t) {
     for(int i = 0; i < n; ++i) s(a + i, b + i, t);
   }
 
+  /**
+   * Swaps x[a .. (a+n-1)] with x[b .. (b+n-1)].
+   * @param a first offset
+   * @param b second offset
+   * @param n number of elements
+   * @param t sort array
+   */
+  private void s(final int a, final int b, final int n, final long[] t) {
+    for(int i = 0; i < n; ++i) s(a + i, b + i, t);
+  }
+
   /**
    * Returns the index of the median of the three indexed integers.
    * @param a first offset
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/util/list/LongList.java basex-8.2.3/basex-core/src/main/java/org/basex/util/list/LongList.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/util/list/LongList.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/util/list/LongList.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,129 @@
+package org.basex.util.list;
+
+import java.util.*;
+
+import org.basex.util.*;
+
+/**
+ * Resizable-array implementation for native long values.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Christian Gruen
+ */
+public class LongList extends ElementList {
+  /** Element container. */
+  protected long[] list;
+
+  /**
+   * Default constructor.
+   */
+  public LongList() {
+    this(Array.CAPACITY);
+  }
+
+  /**
+   * Constructor, specifying an initial internal array size.
+   * @param capacity initial array capacity
+   */
+  public LongList(final int capacity) {
+    list = new long[capacity];
+  }
+
+  /**
+   * Adds an element to the array.
+   * @param element element to be added
+   * @return self reference
+   */
+  public final LongList add(final long element) {
+    long[] lst = list;
+    final int s = size;
+    if(s == lst.length) lst = Arrays.copyOf(lst, newSize());
+    lst[s] = element;
+    list = lst;
+    size = s + 1;
+    return this;
+  }
+
+  /**
+   * Adds elements to the array.
+   * @param elements elements to be added
+   * @return self reference
+   */
+  public final LongList add(final long... elements) {
+    long[] lst = list;
+    final int l = elements.length, s = size, ns = s + l;
+    if(ns > lst.length) lst = Arrays.copyOf(lst, newSize(ns));
+    System.arraycopy(elements, 0, lst, s, l);
+    list = lst;
+    size = ns;
+    return this;
+  }
+
+  /**
+   * Returns the element at the specified position.
+   * @param index index of the element to return
+   * @return element
+   */
+  public final long get(final int index) {
+    return list[index];
+  }
+
+  /**
+   * Returns the uppermost element from the stack.
+   * @return the uppermost element
+   */
+  public final long peek() {
+    return list[size - 1];
+  }
+
+  /**
+   * Pops the uppermost element from the stack.
+   * @return the popped element
+   */
+  public final long pop() {
+    return list[--size];
+  }
+
+  /**
+   * Pushes an element onto the stack.
+   * @param element element
+   */
+  public final void push(final long element) {
+    add(element);
+  }
+
+  /**
+   * Returns an array with all elements.
+   * @return array
+   */
+  public final long[] toArray() {
+    return Arrays.copyOf(list, size);
+  }
+
+  /**
+   * Returns an array with all elements and invalidates the internal array.
+   * Warning: the function must only be called if the list is discarded afterwards.
+   * @return array (internal representation!)
+   */
+  public long[] finish() {
+    final long[] lst = list;
+    list = null;
+    final int s = size;
+    return s == lst.length ? lst : Arrays.copyOf(lst, s);
+  }
+
+  /**
+   * Sorts the data.
+   * @return self reference
+   */
+  public LongList sort() {
+    final int s = size;
+    if(s > 1) Arrays.sort(list, 0, s);
+    return this;
+  }
+
+  @Override
+  public String toString() {
+    return Arrays.toString(toArray());
+  }
+}
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/util/list/StringList.java basex-8.2.3/basex-core/src/main/java/org/basex/util/list/StringList.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/util/list/StringList.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/util/list/StringList.java	2015-07-14 10:54:40.000000000 +0000
@@ -5,7 +5,7 @@
 import org.basex.util.*;
 
 /**
- * This is a simple container for strings.
+ * Resizable-array implementation for strings.
  *
  * @author BaseX Team 2005-15, BSD License
  * @author Christian Gruen
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/util/list/TokenList.java basex-8.2.3/basex-core/src/main/java/org/basex/util/list/TokenList.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/util/list/TokenList.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/util/list/TokenList.java	2015-07-14 10:54:40.000000000 +0000
@@ -8,7 +8,7 @@
 import org.basex.util.hash.*;
 
 /**
- * This is a simple container for tokens (byte arrays).
+ * Resizable-array implementation for tokens (byte arrays).
  *
  * @author BaseX Team 2005-15, BSD License
  * @author Christian Gruen
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/util/options/NumberOption.java basex-8.2.3/basex-core/src/main/java/org/basex/util/options/NumberOption.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/util/options/NumberOption.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/util/options/NumberOption.java	2015-07-14 10:54:40.000000000 +0000
@@ -8,7 +8,7 @@
  */
 public final class NumberOption extends Option<Integer> {
   /** Default value. */
-  public final Integer value;
+  private final Integer value;
 
   /**
    * Default constructor.
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/util/options/Options.java basex-8.2.3/basex-core/src/main/java/org/basex/util/options/Options.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/util/options/Options.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/util/options/Options.java	2015-07-14 10:54:40.000000000 +0000
@@ -65,7 +65,7 @@
   private final HashMap<String, String> free = new HashMap<>();
 
   /** Options, cached from an input file. */
-  private final StringBuilder user = new StringBuilder();
+  private final StringList user = new StringList();
   /** Options file. */
   private IOFile file;
 
@@ -105,7 +105,7 @@
       values.put(e.getKey(), e.getValue());
     for(final Entry<String, String> e : opts.free.entrySet())
       free.put(e.getKey(), e.getValue());
-    user.append(opts.user);
+    user.add(opts.user);
     file = opts.file;
   }
 
@@ -113,34 +113,34 @@
    * Writes the options to disk.
    */
   public final synchronized void write() {
-    final TokenBuilder tmp = new TokenBuilder();
+    final StringList lines = new StringList();
     try {
-      boolean first = true;
       for(final Option<?> opt : options(getClass())) {
         final String name = opt.name();
         if(opt instanceof Comment) {
-          if(!first) tmp.add(NL);
-          tmp.add("# " + name).add(NL);
+          if(!lines.isEmpty()) lines.add("");
+          lines.add("# " + name);
         } else if(opt instanceof NumbersOption) {
           final int[] ints = get((NumbersOption) opt);
           final int is = ints == null ? 0 : ints.length;
-          for(int i = 0; i < is; ++i) tmp.add(name + i + " = " + ints[i]).add(NL);
+          for(int i = 0; i < is; ++i) lines.add(name + i + " = " + ints[i]);
         } else if(opt instanceof StringsOption) {
           final String[] strings = get((StringsOption) opt);
           final int ss = strings == null ? 0 : strings.length;
-          tmp.add(name + " = " + ss).add(NL);
-          for(int i = 0; i < ss; ++i) tmp.add(name + (i + 1) + " = " + strings[i]).add(NL);
+          lines.add(name + " = " + ss);
+          for(int i = 0; i < ss; ++i) lines.add(name + (i + 1) + " = " + strings[i]);
         } else {
-          tmp.add(name + " = " + get(opt)).add(NL);
+          lines.add(name + " = " + get(opt));
         }
-        first = false;
       }
-      tmp.add(NL).add(PROPUSER).add(NL);
-      tmp.add(user.toString());
-      final byte[] content = tmp.finish();
+      lines.add("").add(PROPUSER).add(user);
 
       // only write file if contents have changed
-      if(!file.exists() || !eq(content, file.read())) file.write(content);
+      if(update(lines)) {
+        final TokenBuilder tb = new TokenBuilder();
+        for(final String line : lines) tb.add(line).add(NL);
+        file.write(tb.finish());
+      }
 
     } catch(final Exception ex) {
       Util.errln("% could not be written.", file);
@@ -416,18 +416,11 @@
    * All properties starting with {@code org.basex.} will be assigned as options.
    */
   public final void setSystem() {
-    // collect parameters that start with "org.basex."
-    final StringList sl = new StringList();
-    for(final Object key : System.getProperties().keySet()) {
-      final String k = key.toString();
-      if(k.startsWith(DBPREFIX)) sl.add(k);
-    }
-    // assign properties
-    for(final String key : sl) {
-      final String v = System.getProperty(key);
+    // assign global options
+    for(final Entry<String, String> entry : Prop.entries()) {
+      final String n = entry.getKey(), v = entry.getValue().toString();
       try {
-        final String k = key.substring(DBPREFIX.length()).toUpperCase(Locale.ENGLISH);
-        if(assign(k, v, -1, false)) Util.debug(k + Text.COLS + v);
+        if(assign(n, v, -1, false)) Util.debug(n + Text.COLS + v);
       } catch(final BaseXException ex) {
         Util.errln(ex);
       }
@@ -502,7 +495,7 @@
 
   @Override
   public final synchronized String toString() {
-    // only those options are listed the value of which differs from default value
+    // only those options are listed whose value differs from default value
     final StringBuilder sb = new StringBuilder();
     for(final Entry<String, Object> e : values.entrySet()) {
       final String name = e.getKey();
@@ -532,43 +525,6 @@
   // STATIC METHODS =====================================================================
 
   /**
-   * Returns a system property. If necessary, the key will be converted to lower-case
-   * and prefixed with the {@link Prop#DBPREFIX} string.
-   * @param option option
-   * @return value, or empty string
-   */
-  public static String getSystem(final Option<?> option) {
-    String name = option.name().toLowerCase(Locale.ENGLISH);
-    if(!name.startsWith(DBPREFIX)) name = DBPREFIX + name;
-    final String v = System.getProperty(name);
-    return v == null ? "" : v;
-  }
-
-  /**
-   * Sets a system property if it has not been set before.
-   * @param option option
-   * @param val value
-   */
-  public static void setSystem(final Option<?> option, final Object val) {
-    setSystem(option.name(), val);
-  }
-
-  /**
-   * Sets a system property if it has not been set before. If necessary, the key will
-   * be converted to lower-case and prefixed with the {@link Prop#DBPREFIX} string.
-   * @param key key
-   * @param val value
-   */
-  public static void setSystem(final String key, final Object val) {
-    final String name = key.indexOf('.') == -1 ? DBPREFIX + key.toLowerCase(Locale.ENGLISH) : key;
-    final String value = val.toString();
-    if(System.getProperty(name) == null) {
-      if(value.isEmpty()) System.clearProperty(name);
-      else System.setProperty(name, val.toString());
-    }
-  }
-
-  /**
    * Returns a list of allowed keys.
    * @param option option
    * @param all allowed values
@@ -600,8 +556,6 @@
     return opts.toArray(new Option[opts.size()]);
   }
 
-  // PRIVATE METHODS ====================================================================
-
   /**
    * Reads the configuration file and initializes the options.
    * The file is located in the project home directory.
@@ -623,7 +577,7 @@
             local = true;
             continue;
           }
-          if(local) user.append(line).append(NL);
+          if(local) user.add(line);
 
           if(line.isEmpty() || line.charAt(0) == '#') continue;
           final int d = line.indexOf('=');
@@ -648,7 +602,7 @@
 
           if(local) {
             // cache local options as system properties
-            setSystem(name, val);
+            Prop.put(name, val);
           } else {
             try {
               assign(name, val, num, true);
@@ -684,6 +638,25 @@
   }
 
   /**
+   * Checks if the options file needs to be updated.
+   * @param lines lines of new file
+   * @return result of check
+   * @throws IOException I/O exception
+   */
+  private boolean update(final StringList lines) throws IOException {
+    if(!file.exists()) return true;
+
+    int l = 0;
+    final int ls = lines.size();
+    try(final NewlineInput nli = new NewlineInput(file)) {
+      for(String line; (line = nli.readLine()) != null;) {
+        if(l == ls || !lines.get(l++).equals(line)) return true;
+      }
+    }
+    return l != ls;
+  }
+
+  /**
    * Assigns the specified name and value.
    * @param name name of option
    * @param item value of option
@@ -692,8 +665,8 @@
    * @throws BaseXException database exception
    * @throws QueryException query exception
    */
-  private synchronized boolean assign(final String name, final Item item,
-      final boolean error) throws BaseXException, QueryException {
+  private synchronized boolean assign(final String name, final Item item, final boolean error)
+      throws BaseXException, QueryException {
 
     final Option<?> option = options.get(name);
     if(option == null) {
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/util/Prop.java basex-8.2.3/basex-core/src/main/java/org/basex/util/Prop.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/util/Prop.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/util/Prop.java	2015-07-14 10:54:40.000000000 +0000
@@ -5,9 +5,12 @@
 import java.nio.file.*;
 import java.security.*;
 import java.util.*;
+import java.util.Map.Entry;
+import java.util.concurrent.*;
 
 import org.basex.core.*;
 import org.basex.io.*;
+import org.basex.util.options.*;
 
 /**
  * This class contains constants and system properties which are used all around the project.
@@ -16,8 +19,8 @@
  * @author Christian Gruen
  */
 public final class Prop {
-  /** Private constructor. */
-  private Prop() { }
+  /** Global options. */
+  private static final java.util.Map<String, String> OPTIONS = new ConcurrentHashMap<>();
 
   /** User's home directory. */
   public static final String USERHOME;
@@ -42,7 +45,7 @@
   /** Project name. */
   public static final String NAME = "BaseX";
   /** Code version (may contain major, minor and optional patch number). */
-  public static final String VERSION = version("8.1.1");
+  public static final String VERSION = version("8.2.3");
   /** Main author. */
   public static final String AUTHOR = "Christian Gr\u00FCn";
   /** Co-authors (1). */
@@ -108,6 +111,11 @@
   /** GUI mode. */
   public static boolean gui;
 
+  /** Private constructor. */
+  private Prop() { }
+
+  // STATIC METHODS =====================================================================
+
   /**
    * <p>Determines the project's home directory for storing property files
    * and directories. The directory is chosen as follows:</p>
@@ -177,4 +185,77 @@
     if(revision != null) result.append(' ').append(revision);
     return result.toString();
   }
+
+  /**
+   * Sets a global option.
+   * @param option option
+   * @param value value
+   */
+  public static void put(final Option<?> option, final Object value) {
+    put(option.name(), value);
+  }
+
+  /**
+   * Sets a global option.
+   * @param name name of the option
+   * @param value value
+   */
+  public static void put(final String name, final Object value) {
+    OPTIONS.put(normalizeKey(name), value.toString());
+  }
+
+  /**
+   * Removes a global option.
+   * @param option option
+   */
+  public static void remove(final Option<?> option) {
+    OPTIONS.remove(option);
+  }
+
+  /**
+   * Returns a system property or global option. System properties override global options.
+   * @param option option
+   * @return value, or empty string
+   */
+  public static String get(final Option<?> option) {
+    String v = System.getProperty(DBPREFIX + option.name().toLowerCase(Locale.ENGLISH));
+    if(v == null) v = OPTIONS.get(option);
+    return v == null ? "" : v;
+  }
+
+  /**
+   * Returns the names of all system properties and global options.
+   * System properties override global options.
+   * @return entry set
+   */
+  public static Set<Entry<String, String>> entries() {
+    // override with system properties
+    final HashMap<String, String> entries = new HashMap<>();
+    entries.putAll(OPTIONS);
+    // override with system properties
+    for(final Object key : System.getProperties().keySet()) {
+      final String name = key.toString();
+      if(name.startsWith(DBPREFIX)) entries.put(normalizeKey(name), System.getProperty(name));
+    }
+    return entries.entrySet();
+  }
+
+  /**
+   * Sets a system property if it has not been set before.
+   * @param key key
+   * @param value value
+   */
+  public static void setSystem(final String key, final String value) {
+    if(System.getProperty(key) == null) System.setProperty(key, value);
+  }
+
+  /**
+   * Normalizes the key of an option. Removes {@link #DBPREFIX} and converts the key to upper-case.
+   * @param name name of the option
+   * @return normalized string
+   */
+  private static String normalizeKey(final String name) {
+    final String n = name.startsWith(DBPREFIX) ? name.substring(DBPREFIX.length()) : name;
+    return n.toUpperCase(Locale.ENGLISH);
+  }
 }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/util/Reflect.java basex-8.2.3/basex-core/src/main/java/org/basex/util/Reflect.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/util/Reflect.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/util/Reflect.java	2015-07-14 10:54:40.000000000 +0000
@@ -12,7 +12,7 @@
  */
 public final class Reflect {
   /** Cached constructors. */
-  private static final HashMap<String, Constructor<?>> CONS = new HashMap<>();
+  private static final HashMap<String, Constructor<?>> CONSTRUCTORS = new HashMap<>();
   /** Cached classes. */
   private static final HashMap<String, Class<?>> CLASSES = new HashMap<>();
   /** Cached fields. */
@@ -122,7 +122,7 @@
     final String key = sb.toString();
 
     @SuppressWarnings("unchecked")
-    Constructor<O> m = (Constructor<O>) CONS.get(key);
+    Constructor<O> m = (Constructor<O>) CONSTRUCTORS.get(key);
     if(m == null) {
       try {
         try {
@@ -131,7 +131,7 @@
           m = clazz.getDeclaredConstructor(types);
           m.setAccessible(true);
         }
-        CONS.put(key, m);
+        CONSTRUCTORS.put(key, m);
       } catch(final Throwable ex) {
         Util.debug(ex);
       }
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/util/Token.java basex-8.2.3/basex-core/src/main/java/org/basex/util/Token.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/util/Token.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/util/Token.java	2015-07-14 10:54:40.000000000 +0000
@@ -36,8 +36,6 @@
   public static final byte[] TRUE = token("true");
   /** Token 'false'. */
   public static final byte[] FALSE = token("false");
-  /** Token 'null'. */
-  public static final byte[] NULL = token("null");
   /** Token 'NaN'. */
   public static final byte[] NAN = token("NaN");
   /** Token 'INF'. */
diff -Nru basex-8.1.1/basex-core/src/main/java/org/basex/util/XMLAccess.java basex-8.2.3/basex-core/src/main/java/org/basex/util/XMLAccess.java
--- basex-8.1.1/basex-core/src/main/java/org/basex/util/XMLAccess.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/java/org/basex/util/XMLAccess.java	2015-07-14 10:54:40.000000000 +0000
@@ -23,9 +23,9 @@
    * @param name name
    * @return iterator
    */
-  public static AxisIter children(final ANode node, final byte[] name) {
-    final AxisIter children = node.children();
-    return new AxisIter() {
+  public static BasicNodeIter children(final ANode node, final byte[] name) {
+    final BasicNodeIter children = node.children();
+    return new BasicNodeIter() {
       @Override
       public ANode next() {
         for(ANode child; (child = children.next()) != null;) {
diff -Nru basex-8.1.1/basex-core/src/main/resources/lang/Dutch.lang basex-8.2.3/basex-core/src/main/resources/lang/Dutch.lang
--- basex-8.1.1/basex-core/src/main/resources/lang/Dutch.lang	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/resources/lang/Dutch.lang	2015-07-14 10:54:40.000000000 +0000
@@ -53,7 +53,7 @@
 comment              = Commentaar
 community            = Gemeenschap
 compiling            = Compileren
-connection_error     = Communicatie met de server mislukt.
+connection_error     = Communicatie met de server mislukt
 copy                 = Kopieer
 copy_db              = Kopieer database
 copy_path            = Kopieer pad
@@ -114,13 +114,6 @@
 entries_%            = % entries
 error                = Fout
 evaluating           = Evalueren
-event_created_%      = Event '%' is gecreeerd.
-event_dropped_%      = Event '%' is verwijderd.
-event_exists_%       = Event '%' bestaat al.
-event_not_watched_%  = Event '%' werd niet bekeken.
-event_unknown_%      = Event '%' is onbekend.
-event_watched_%      = Event '%' wordt al bekeken.
-events_%             = % event(s)
 exec_error_%         = Kon % niet uitvoeren
 exit                 = Stop
 expecting_cmd        = Commando verwacht.
@@ -277,7 +270,7 @@
 pkg_replaced_%_%     = Package '%' vervangen in %.
 please_wait          = Een ogenblik
 plot                 = Plot
-port_twice_%         = Poort '%' was twee peer gespecificeerd.
+port                 = poort
 preferences          = Voorkeuren
 printed              = Geprint
 printing             = Printen
@@ -343,9 +336,9 @@
 skipped              = Overgeslagen
 sort                 = Sorteer
 split_input_lines    = Splits input op in regels
-srv_running          = Server loopt al of toegang ontzegd.
-srv_started_port_%   = Server is gestart (poort: %)
-srv_stopped_port_%   = Server is gestopt (poort: %)
+srv_running          = Server loopt al of toegang ontzegd
+srv_started          = Server is gestart
+srv_stopped          = Server is gestopt
 standard             = Standaard
 status_bar           = Statusbalk
 stemming             = Stam zoeken
@@ -380,7 +373,6 @@
 unknown_host_x       = Onbekende host '%'.
 unknown_option_%     = Onbekende optie '%'.
 unknown_user_%       = Gebruiker '%' is onbekend.
-unwatching_event_%   = Event '%' niet langer gemonitord.
 up_to_date           = bijgewerkt
 updated              = Bijgewerkt
 use_catalog_file     = Gebruik XML Catalog bestand
@@ -398,7 +390,6 @@
 version              = Versie
 view                 = View
 visualization        = Visualisatie
-watching_event_%     = Monitor event '%'.
 whole_word           = Heel woord
 write_locking        = Write Locking
 yes                  = Ja
@@ -448,7 +439,6 @@
 c_create22           = Maakt een backup van database [%]
 c_create23           = Maakt de opgegeven index
 c_create24           = Creeert de opgegeven gebruiker
-c_create25           = Creeert het event
 c_delete1            = Verwijder resources uit de database.
 c_delete2            = Verwijdert resources uit de actuele database.
 c_drop1              = Verwijder database, index, gebruiker, backup of event.
@@ -457,7 +447,6 @@
 c_drop22             = Verwijdert de opgegeven index
 c_drop23             = Verwijdert de opgegeven gebruiker (van een database).
 c_drop24             = Verwijdert de database backup
-c_drop25             = Verwijdert de event
 c_execute1           = Voer commando script uit.
 c_execute2           = Voer het bestand [%] als commando script uit.
 c_exit1              = Stop applicatie.
@@ -514,7 +503,6 @@
 c_show23             = Toont actuele database sessies.
 c_show24             = Toont gebruikers (van een database).
 c_show25             = Toont backups.
-c_show26             = Toont events.
 c_store1             = Sla ruwe data op.
 c_store2             = Slaat ruwe data op in de gespecificeerde [%].
 c_test1              = Run XQUnit tests.
diff -Nru basex-8.1.1/basex-core/src/main/resources/lang/English.lang basex-8.2.3/basex-core/src/main/resources/lang/English.lang
--- basex-8.1.1/basex-core/src/main/resources/lang/English.lang	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/resources/lang/English.lang	2015-07-14 10:54:40.000000000 +0000
@@ -53,7 +53,7 @@
 comment              = Comment
 community            = Community
 compiling            = Compiling
-connection_error     = Can't communicate with the server.
+connection_error     = Connection failed
 copy                 = Copy
 copy_db              = Copy Database
 copy_path            = Copy Path
@@ -114,13 +114,6 @@
 entries_%            = % entries
 error                = Error
 evaluating           = Evaluating
-event_created_%      = Event '%' was created.
-event_dropped_%      = Event '%' was dropped.
-event_exists_%       = Event '%' already exists.
-event_not_watched_%  = Event '%' was not watched.
-event_unknown_%      = Event '%' is unknown.
-event_watched_%      = Already watching event '%'.
-events_%             = % event(s)
 exec_error_%         = Could not execute %
 exit                 = Exit
 expecting_cmd        = Expecting command.
@@ -277,7 +270,7 @@
 pkg_replaced_%_%     = Package '%' replaced in %.
 please_wait          = Please Wait
 plot                 = Plot
-port_twice_%         = Port '%' was specified twice.
+port                 = port
 preferences          = Preferences
 printed              = Printed
 printing             = Printing
@@ -343,9 +336,9 @@
 skipped              = Skipped
 sort                 = Sort
 split_input_lines    = Splits input into lines
-srv_running          = Server is running or permission was denied.
-srv_started_port_%   = Server was started (port: %)
-srv_stopped_port_%   = Server was stopped (port: %)
+srv_running          = Server is running or permission was denied
+srv_started          = Server was started
+srv_stopped          = Server was stopped
 standard             = Standard
 status_bar           = Status Bar
 stemming             = Stemming
@@ -380,7 +373,6 @@
 unknown_host_x       = Unknown host '%'.
 unknown_option_%     = Unknown option '%'.
 unknown_user_%       = Unknown user '%'.
-unwatching_event_%   = Event '%' unwatched.
 up_to_date           = Up-to-date
 updated              = Updated
 use_catalog_file     = Use XML Catalog file
@@ -398,7 +390,6 @@
 version              = Version
 view                 = View
 visualization        = Visualization
-watching_event_%     = Watch event '%'.
 whole_word           = Whole Word
 write_locking        = Write Locking
 yes                  = Yes
@@ -448,7 +439,6 @@
 c_create22           = creates a backup of the database [%]
 c_create23           = creates the specified index
 c_create24           = creates the specified user
-c_create25           = creates the event
 c_delete1            = Delete resources from database.
 c_delete2            = Deletes resources from the currently opened database.
 c_drop1              = Drop database, index, user, backup or event.
@@ -457,7 +447,6 @@
 c_drop22             = drops the specified index
 c_drop23             = drops the specified user (on a database).
 c_drop24             = drops the database backup
-c_drop25             = drops the event
 c_execute1           = Execute command script.
 c_execute2           = Executes the specified [%] as command script.
 c_exit1              = Exit application.
@@ -514,7 +503,6 @@
 c_show23             = shows current database sessions.
 c_show24             = shows users (on a database).
 c_show25             = shows backups.
-c_show26             = shows events.
 c_store1             = Store raw data.
 c_store2             = Stores raw data to the specified [%].
 c_test1              = Run XQUnit tests.
diff -Nru basex-8.1.1/basex-core/src/main/resources/lang/French.lang basex-8.2.3/basex-core/src/main/resources/lang/French.lang
--- basex-8.1.1/basex-core/src/main/resources/lang/French.lang	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/resources/lang/French.lang	2015-07-14 10:54:40.000000000 +0000
@@ -53,7 +53,7 @@
 comment              = Commentaire
 community            = Communauté
 compiling            = Compilation
-connection_error     = Pas de communication avec le serveur.
+connection_error     = Pas de communication avec le serveur
 copy                 = Copier
 copy_db              = Copier la base de données
 copy_path            = Copier le chemin
@@ -114,13 +114,6 @@
 entries_%            = % entrées
 error                = Erreur
 evaluating           = Évaluation
-event_created_%      = L'évènement '%' a été créé.
-event_dropped_%      = L'évènement  '%' a été supprimé.
-event_exists_%       = L'évènement  '%' existe déjà.
-event_not_watched_%  = L'évènement  '%' n'est pas observé.
-event_unknown_%      = L'évènement  '%' est inconnu.
-event_watched_%      = L'évènement '%' est déjà observé.
-events_%             = % évènement(s)
 exec_error_%         = Impossible d'exécuter %
 exit                 = Quitter
 expecting_cmd        = Commande attendue.
@@ -277,7 +270,7 @@
 pkg_replaced_%_%     = Paquet '%' remplacé (%)
 please_wait          = Veuillez patienter
 plot                 = Diagramme
-port_twice_%         = Le port '%' a été spécifié deux fois.
+port                 = port
 preferences          = Préférences
 printed              = Imprimé
 printing             = Impression
@@ -343,9 +336,9 @@
 skipped              = Ignoré
 sort                 = Sort
 split_input_lines    = Éclater l'entrée en lignes
-srv_running          = Serveur déjà démarré ou permission refusée.
-srv_started_port_%   = Serveur démarré (port: %)
-srv_stopped_port_%   = Serveur arrêté (port: %)
+srv_running          = Serveur déjà démarré ou permission refusée
+srv_started          = Serveur démarré
+srv_stopped          = Serveur arrêté
 standard             = Standard
 status_bar           = Barre d'état
 stemming             = Stemming
@@ -380,7 +373,6 @@
 unknown_host_x       = Serveur '%' inconnu.
 unknown_option_%     = Option '%' inconnue.
 unknown_user_%       = Utilisateur '%' inconnu.
-unwatching_event_%   = Evènement '%' non observé.
 up_to_date           = À jour
 updated              = Mis à jour
 use_catalog_file     = Utiliser un fichier de catalogue XML Catalog
@@ -398,7 +390,6 @@
 version              = Version
 view                 = Affichage
 visualization        = Visualisation
-watching_event_%     = Observation de l'évènement '%'.
 whole_word           = Mot entier
 write_locking        = Blocage en écriture
 yes                  = Oui
@@ -448,7 +439,6 @@
 c_create22           = crée une sauvegarde pour la base de données [%]
 c_create23           = crée l'index specifié
 c_create24           = crée l'utilisateur specifié
-c_create25           = crée l'évènement
 c_delete1            = Supprimer les ressources.
 c_delete2            = Supprime les ressources de la base de données courante.
 c_drop1              = Supprimer la base de données, l'index, l'utilisateur, la sauvegarde ou l'évènement.
@@ -457,7 +447,6 @@
 c_drop22             = supprime l'index spécifié 
 c_drop23             = supprime l'utilisateur spécifié (sur une base de données).
 c_drop24             = supprime la sauvegarde de la base de données
-c_drop25             = supprime l'évènement
 c_execute1           = Exécuter le script
 c_execute2           = Exécute le [%] spécifié comme script
 c_exit1              = Quitter l'application.
@@ -514,7 +503,6 @@
 c_show23             = montre les sessions de la base de données courante.
 c_show24             = montre les utilisateurs (sur une base de données).
 c_show25             = montre les backups.
-c_show26             = montre les événements.
 c_store1             = Enregistrer les données brutes.
 c_store2             = Enregistre les données brutes dans le [%] specifié.
 c_test1              = Exécute les tests XQUnit.
diff -Nru basex-8.1.1/basex-core/src/main/resources/lang/German.lang basex-8.2.3/basex-core/src/main/resources/lang/German.lang
--- basex-8.1.1/basex-core/src/main/resources/lang/German.lang	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/resources/lang/German.lang	2015-07-14 10:54:40.000000000 +0000
@@ -53,7 +53,7 @@
 comment              = Kommentar
 community            = Community
 compiling            = Kompilierung
-connection_error     = Der Server ist nicht erreichbar.
+connection_error     = Der Server ist nicht erreichbar
 copy                 = Kopieren
 copy_db              = Datebank kopieren
 copy_path            = Pfad kopieren
@@ -114,13 +114,6 @@
 entries_%            = % Einträge
 error                = Fehler
 evaluating           = Ausführung
-event_created_%      = Event '%' erzeugt.
-event_dropped_%      = Event '%' entfernt.
-event_exists_%       = Event '%' existiert schon.
-event_not_watched_%  = Event '%' wurde nicht beobachtet.
-event_unknown_%      = Unbekannter Event '%'.
-event_watched_%      = Event '%' wird schon beobachtet.
-events_%             = % Event(s)
 exec_error_%         = % konnte nicht ausgeführt werden
 exit                 = Beenden
 expecting_cmd        = Befehl erwartet.
@@ -277,7 +270,7 @@
 pkg_replaced_%_%     = Das Paket '%' wurde ersetzt (%).
 please_wait          = Bitte warten
 plot                 = Plot
-port_twice_%         = Der Port '%' wurde mehrfach angegeben.
+port                 = Port
 preferences          = Einstellungen
 printed              = Ausgegeben
 printing             = Ausgabe
@@ -343,9 +336,9 @@
 skipped              = Übersprungen
 sort                 = Sortieren
 split_input_lines    = Trennt den Text in einzelne Zeilen auf
-srv_running          = Der Server läuft, oder der Zugriff wurde untersagt.
-srv_started_port_%   = Server wurde gestartet (Port: %)
-srv_stopped_port_%   = Server wurde gestoppt (Port: %)
+srv_running          = Der Server läuft, oder der Zugriff wurde untersagt
+srv_started          = Server wurde gestartet
+srv_stopped          = Server wurde gestoppt
 standard             = Standard
 status_bar           = Statusleiste
 stemming             = Stemming
@@ -380,7 +373,6 @@
 unknown_host_x       = Unbekannter Host '%'.
 unknown_option_%     = Unbekannte Option '%'.
 unknown_user_%       = Unbekannter Benutzer '%'.
-unwatching_event_%   = Von Event '%' abgemeldet.
 up_to_date           = Up-to-date
 updated              = Updates
 use_catalog_file     = XML Katalog-Datei
@@ -398,7 +390,6 @@
 version              = Version
 view                 = Ansicht
 visualization        = Visualisierung
-watching_event_%     = Beobachte Event '%'.
 whole_word           = Ganzes Wort
 write_locking        = Write Locks
 yes                  = Ja
@@ -448,7 +439,6 @@
 c_create22           = erstellt ein Backup der Datenbank [%]
 c_create23           = erstellt den angegebenen Index
 c_create24           = erstellt den angegebenen Benutzer
-c_create25           = erstellt den angegebenen Event
 c_delete1            = Entfernen von Ressourcen.
 c_delete2            = Entfernt Ressourcen aus der geöffneten Datenbank.
 c_drop1              = Entfernen einer Datenbank, eines Index oder Benutzers.
@@ -457,7 +447,6 @@
 c_drop22             = entfernt den angegebenen Index
 c_drop23             = entfernt den angegebenen Benutzer (einer Datenbank).
 c_drop24             = entfernt das Datenbank-Backup
-c_drop25             = entfernt den Event
 c_execute1           = Execute command script.
 c_execute2           = Executes the specified [%] as command script.
 c_exit1              = Beenden des Programms.
@@ -514,7 +503,6 @@
 c_show23             = zeigt aktuelle Datenbankverbindungen.
 c_show24             = zeigt registrierte Benutzer (einer Datenbank).
 c_show25             = zeigt Backups an.
-c_show26             = zeigt Events an.
 c_store1             = Speicherung von Rohdaten.
 c_store2             = Speichert Rohdaten am angegebenen Pfad [%].
 c_test1              = Ausführung von XQUnit-Tests.
diff -Nru basex-8.1.1/basex-core/src/main/resources/lang/Hungarian.lang basex-8.2.3/basex-core/src/main/resources/lang/Hungarian.lang
--- basex-8.1.1/basex-core/src/main/resources/lang/Hungarian.lang	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/resources/lang/Hungarian.lang	2015-07-14 10:54:40.000000000 +0000
@@ -53,7 +53,7 @@
 comment              = Megjegyzés
 community            = Közösség
 compiling            = Fordítás
-connection_error     = Nincs kapcsolat a szerverrel.
+connection_error     = Nincs kapcsolat a szerverrel
 copy                 = Másolás
 copy_db              = Adatbázis másolása
 copy_path            = Útvonal másolása
@@ -114,13 +114,6 @@
 entries_%            = % bejegyzés
 error                = Hiba
 evaluating           = Végrehajtás
-event_created_%      = '%' esemény létrejött.
-event_dropped_%      = '%' eseményt eldobta.
-event_exists_%       = '%' esemény már létezik.
-event_not_watched_%  = '%' eseményt nem figyelt.
-event_unknown_%      = '%' esemény ismeretlen.
-event_watched_%      = '%' eseményt már figyeli.
-events_%             = % esemény
 exec_error_%         = % nem futtatható
 exit                 = Kilépés
 expecting_cmd        = Parancs az elvárt.
@@ -277,7 +270,7 @@
 pkg_replaced_%_%     = '%' csomag lecserélve % alatt.
 please_wait          = Kérem várjon
 plot                 = Pontok
-port_twice_%         = '%' port kétszer lett megadva.
+port                 = port
 preferences          = Beállítások
 printed              = Megjelenítve
 printing             = Megjelenítés
@@ -301,7 +294,7 @@
 reopen_file_%        = Újra megnyitja (%) és eldobja a változásokat?
 replace_all          = Összes cseréje
 replace_with         = Csere erre:
-repository_path      = Repository Path
+repository_path      = Adattár úvonala
 requires_restart     = újraindítás szükséges
 res_added_%          = Erőforrás(ok) hozzáadva % alatt.
 res_deleted_%_%      = % erőforrás törölve % alatt.
@@ -343,9 +336,9 @@
 skipped              = Kihagyva
 sort                 = Rendezés
 split_input_lines    = Bemenet sorokra tördelése
-srv_running          = Szerver fut vagy hozzáférés megtagadva.
-srv_started_port_%   = Szerver elindult (port: %)
-srv_stopped_port_%   = Szerver leállt (port: %)
+srv_running          = Szerver fut vagy hozzáférés megtagadva
+srv_started          = Szerver elindult
+srv_stopped          = Szerver leállt
 standard             = Standard
 status_bar           = Állapotsor
 stemming             = Csupaszítás
@@ -380,7 +373,6 @@
 unknown_host_x       = Ismeretlen kiszolgáló '%'.
 unknown_option_%     = Ismeretlen beállítás '%'.
 unknown_user_%       = Ismeretlen felhasználó '%'.
-unwatching_event_%   = '%' esemény nem figyelt.
 up_to_date           = Naprakész
 updated              = Frissítve
 use_catalog_file     = XML katalógusfájl használata
@@ -398,7 +390,6 @@
 version              = Verzió
 view                 = Nézet
 visualization        = Megjelenítés
-watching_event_%     = '%' esemény figyelése.
 whole_word           = Egész szó
 write_locking        = Írási zárolása
 yes                  = Igen
@@ -448,7 +439,6 @@
 c_create22           = létrehozza az adatbázis egy biztonsági másolatát [%]
 c_create23           = létrehozza a kívánt indexet
 c_create24           = létrehozza a kívánt felhasználót
-c_create25           = létrehozza az eseményt
 c_delete1            = Erőforrások törlése az adatbázisból.
 c_delete2            = Törli az erőforrásokat a jelenleg megnyitott adatbázisból.
 c_drop1              = Adatbázis, index, felhasználó, biztonsági másolat vagy esemény eldobása.
@@ -457,7 +447,6 @@
 c_drop22             = eldobja a kívánt indexet
 c_drop23             = eldobja a kívánt felhasználót (az adatbázisban).
 c_drop24             = eldobja az adatbázis biztonsági másolatot
-c_drop25             = eldobja az eseményt
 c_execute1           = Parancsszkript futtatása.
 c_execute2           = Futtatja parancsszkriptként a kívánt [%]-t.
 c_exit1              = Alkalmazás bezárása.
@@ -514,7 +503,6 @@
 c_show23             = megjelenít jelenlegi adatbázis munkameneteket.
 c_show24             = megjelenít felhasználókat (az adatbázisban).
 c_show25             = megjelenít biztonsági mentéseket.
-c_show26             = megjelenít eseményeket.
 c_store1             = Raw adat tárolása.
 c_store2             = Raw adatot tárol a kívánt [%]-n.
 c_test1              = XQUnit tesztek futtatása.
diff -Nru basex-8.1.1/basex-core/src/main/resources/lang/Indonesian.lang basex-8.2.3/basex-core/src/main/resources/lang/Indonesian.lang
--- basex-8.1.1/basex-core/src/main/resources/lang/Indonesian.lang	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/resources/lang/Indonesian.lang	2015-07-14 10:54:40.000000000 +0000
@@ -53,7 +53,7 @@
 comment              = Komentar
 community            = Komunitas
 compiling            = Mengompilasi
-connection_error     = Tidak dapat terhubung dengan server.
+connection_error     = Tidak dapat terhubung dengan server
 copy                 = Salin
 copy_db              = Salin Basisdata
 copy_path            = Salin Rintis
@@ -114,13 +114,6 @@
 entries_%            = % masukan
 error                = Galat
 evaluating           = Mengevaluasi
-event_created_%      = Kejadian '%' telah dibuat.
-event_dropped_%      = Kejadian '%' telah dihapus.
-event_exists_%       = Kejadian '%' sudah ada.
-event_not_watched_%  = Kejadian '%' tidak diamati.
-event_unknown_%      = Kejadian '%' tidak dikenal.
-event_watched_%      = Sudah sedang mengamati kejadian '%'.
-events_%             = % kejadian
 exec_error_%         = Tidak dapat menjalankan %
 exit                 = Keluar
 expecting_cmd        = Mengharapkan perintah.
@@ -277,7 +270,7 @@
 pkg_replaced_%_%     = Paket '%' diganti dalam %.
 please_wait          = Mohon tunggu
 plot                 = Plot
-port_twice_%         = Port '%' dinyatakan dua kali.
+port                 = port
 preferences          = Perasa
 printed              = Tercetak
 printing             = Mencetak
@@ -343,9 +336,9 @@
 skipped              = Terlewat
 sort                 = Sortir
 split_input_lines    = Potong masukan menjadi baris
-srv_running          = Servis sudah berjalan atau izin ditolak.
-srv_started_port_%   = Server sudah dijalankan (port: %)
-srv_stopped_port_%   = Server sudah dihentikan (port: %)
+srv_running          = Servis sudah berjalan atau izin ditolak
+srv_started          = Server sudah dijalankan
+srv_stopped          = Server sudah dihentikan
 standard             = Standar
 status_bar           = Batang status
 stemming             = Memotong
@@ -380,7 +373,6 @@
 unknown_host_x       = Host '%' tidak diketahui.
 unknown_option_%     = Opsi '%' tidak diketahui.
 unknown_user_%       = Pengguna '%' tidak diketahui.
-unwatching_event_%   = Kejadian '%' tidak diamati.
 up_to_date           = Mutakhir
 updated              = Termutakhirkan
 use_catalog_file     = Gunakan berkas katalog XML
@@ -398,7 +390,6 @@
 version              = Versi
 view                 = Lihat
 visualization        = Visualisasi
-watching_event_%     = Amati kejadian '%'.
 whole_word           = Seluruh kata
 write_locking        = Tulis pengunci
 yes                  = Ya
@@ -448,7 +439,6 @@
 c_create22           = buat cadangan dari basisdata [%]
 c_create23           = buat indeks yang ditentukan
 c_create24           = buat pengguna yang ditentukan
-c_create25           = buat kejadian
 c_delete1            = Hapus sumber daya dari basisdata.
 c_delete2            = Hapus sumber daya dari basisdata yang sedang terbuka.
 c_drop1              = Hapus basisdata, indeks, cadangan, atau pengguna.
@@ -457,7 +447,6 @@
 c_drop22             = hapus indeks yang ditentukan
 c_drop23             = hapus pengguna yang ditentukan (dalam satu basisdata).
 c_drop24             = hapus cadangan basisdata
-c_drop25             = hapus kejadian
 c_execute1           = Jalankan skrip perintah.
 c_execute2           = Jalankan [%] sebagai skrip perintah.
 c_exit1              = Keluar dari aplikasi.
@@ -514,7 +503,6 @@
 c_show23             = tampilkan sesi basisdata kini.
 c_show24             = tampilkan pengguna (pada satu basisdata).
 c_show25             = tampilkan cadangan.
-c_show26             = tampilkan kejadian.
 c_store1             = Simpan data mentah.
 c_store2             = Simpan data mentah ke [%] yang ditetapkan.
 c_test1              = Jalankan pengujian XQUnit.
diff -Nru basex-8.1.1/basex-core/src/main/resources/lang/Italian.lang basex-8.2.3/basex-core/src/main/resources/lang/Italian.lang
--- basex-8.1.1/basex-core/src/main/resources/lang/Italian.lang	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/resources/lang/Italian.lang	2015-07-14 10:54:40.000000000 +0000
@@ -53,7 +53,7 @@
 comment              = Commento
 community            = Comunità
 compiling            = Compilando
-connection_error     = Impossibile comunicare con il Server.
+connection_error     = Impossibile comunicare con il Server
 copy                 = Copia
 copy_db              = Copia base di dati
 copy_path            = Copia percorso
@@ -114,13 +114,6 @@
 entries_%            = % occorrenze
 error                = Errore
 evaluating           = Eseguendo
-event_created_%      = L'evento '%' è stato creato.
-event_dropped_%      = L'evento '%' è stato rimosso.
-event_exists_%       = L'evento '%' esiste già.
-event_not_watched_%  = L'evento '%' non è stato osservato.
-event_unknown_%      = L'evento '%' è sconosciuto.
-event_watched_%      = Stai già osservando l'evento '%'.
-events_%             = % event(i)
 exec_error_%         = Impossibile eseguire %
 exit                 = Esci
 expecting_cmd        = Attendo un comando.
@@ -277,7 +270,7 @@
 pkg_replaced_%_%     = Pacchetto '%' sostituiti in %.
 please_wait          = Attendi
 plot                 = Grafico
-port_twice_%         = La porta '%' è stata specificata due volte.
+port                 = porta
 preferences          = Impostazioni
 printed              = Stampato
 printing             = Stampando
@@ -343,9 +336,9 @@
 skipped              = Saltato
 sort                 = Ordina
 split_input_lines    = Dividi l'input in linee
-srv_running          = Il server sta lavorando o il permesso è stato negato.
-srv_started_port_%   = Server è stato avviato (porta: %)
-srv_stopped_port_%   = Server è stato spento (porta: %)
+srv_running          = Il server sta lavorando o il permesso è stato negato
+srv_started          = Server è stato avviato
+srv_stopped          = Server è stato spento
 standard             = Normale
 status_bar           = Barra di stato
 stemming             = Radice linguistica (Inglese)
@@ -380,7 +373,6 @@
 unknown_host_x       = Host sconosciuto '%'.
 unknown_option_%     = Opzione sconosciuta '%'.
 unknown_user_%       = L'utente '%' è sconosciuto.
-unwatching_event_%   = Evento '%' non osservato.
 up_to_date           = Aggiornato
 updated              = Aggiornato
 use_catalog_file     = Usa il documento del catalogo XML
@@ -398,7 +390,6 @@
 version              = Versione
 view                 = Visualizza
 visualization        = Visualizzazione
-watching_event_%     = Guarda l'evento '%'.
 whole_word           = Parola Intera
 write_locking        = Locking in scrittura
 yes                  = Sì
@@ -448,7 +439,6 @@
 c_create22           = crea un backup della base di dati [%]
 c_create23           = crea l'indice specificato
 c_create24           = crea l'utente specificato
-c_create25           = crea un evento
 c_delete1            = Rimuovi risorse.
 c_delete2            = Rimuovi risorse della base di dati corrente.
 c_drop1              = Cancella base di dati, indice, utente, backup o evento.
@@ -457,7 +447,6 @@
 c_drop22             = cancella l'indice specificato
 c_drop23             = cancella l'utente specificato (su una base di dati).
 c_drop24             = rimuovi il backup della base di dati
-c_drop25             = rimuovi l'evento
 c_execute1           = Esegui lo script dei comandi.
 c_execute2           = Esegui [%] come script di comandi.
 c_exit1              = Esci dall'applicazione.
@@ -514,7 +503,6 @@
 c_show23             = mostra le sessioni aperte.
 c_show24             = mostra gli utenti (su una base di dati).
 c_show25             = mostra i backup.
-c_show26             = mostra gli event.
 c_store1             = Archivia i dati grezzi.
 c_store2             = Archivia i dati grezzi in [%].
 c_test1              = Lancia i test XQUnit.
diff -Nru basex-8.1.1/basex-core/src/main/resources/lang/Japanese.lang basex-8.2.3/basex-core/src/main/resources/lang/Japanese.lang
--- basex-8.1.1/basex-core/src/main/resources/lang/Japanese.lang	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/resources/lang/Japanese.lang	2015-07-14 10:54:40.000000000 +0000
@@ -53,7 +53,7 @@
 comment              = コメント
 community            = コミュニティ
 compiling            = コンパイル中
-connection_error     = サーバーと通信できません。
+connection_error     = サーバーと通信できません
 copy                 = コピー
 copy_db              = ドキュメントのコピー
 copy_path            = パスのコピー
@@ -114,13 +114,6 @@
 entries_%            = % 個のエントリー
 error                = エラー
 evaluating           = 計算中
-event_created_%      = イベント '%' が作成されました。
-event_dropped_%      = イベント '%' が削除されました。
-event_exists_%       = イベント '%' は既に存在しています。
-event_not_watched_%  = イベント '%' は監視されていません。
-event_unknown_%      = イベント '%' は不明です。
-event_watched_%      = 既にイベントを監視しています '%'。
-events_%             = % イベント
 exec_error_%         = %を実行できませんでした。
 exit                 = 終了
 expecting_cmd        = 予想されるコマンド
@@ -277,7 +270,7 @@
 pkg_replaced_%_%     = パッケージ '%' は % に置き換えられました。
 please_wait          = お待ち下さい
 plot                 = プロット
-port_twice_%         = ポート番号 '%' に対する指定が重複しています。
+port                 = port
 preferences          = 設定
 printed              = 印刷しました
 printing             = 印刷中
@@ -343,9 +336,9 @@
 skipped              = スキップしました。
 sort                 = ソート
 split_input_lines    = 改行で分割する
-srv_running          = サーバーが既に起動しているか、権限が足りません。
-srv_started_port_%   = サーバーを開始しました (port: %)
-srv_stopped_port_%   = サーバーを停止しました (port: %)
+srv_running          = サーバーが既に起動しているか、権限が足りません
+srv_started          = サーバーを開始しました
+srv_stopped          = サーバーを停止しました
 standard             = 通常
 status_bar           = ステータスバー
 stemming             = 語幹処理
@@ -380,7 +373,6 @@
 unknown_host_x       = '%' は不明なホスト名です。
 unknown_option_%     = '%' は不明なオプションです。
 unknown_user_%       = ユーザー '%' が見付かりません。
-unwatching_event_%   = イベント '%' は監視外です。
 up_to_date           = 最新
 updated              = 更新しました
 use_catalog_file     = XMLカタログファイルを使用する
@@ -398,7 +390,6 @@
 version              = バージョン
 view                 = ビュー
 visualization        = ビジュアライゼーション
-watching_event_%     = イベント '%' を監視しています.
 whole_word           = 単語全体
 write_locking        = 書き込みロック
 yes                  = はい
@@ -448,7 +439,6 @@
 c_create22           = データベースのバックアップを [%] に作成します
 c_create23           = 指定されたインデックスを作成します。
 c_create24           = 指定されたユーザーを作成します。
-c_create25           = イベントを作成します。
 c_delete1            = リソースの削除
 c_delete2            = 現在のデータベースからリソーストを削除します。
 c_drop1              = データベース、インデックス、ユーザ、バックアップ、またはイベントの削除
@@ -457,7 +447,6 @@
 c_drop22             = 指定されたインデックスを削除します。
 c_drop23             = 指定された (database 上の) ユーザを削除します。
 c_drop24             = データベースのバックアップを削除します。
-c_drop25             = イベントを削除します。
 c_execute1           = コマンドスクリプトを実行します。
 c_execute2           = 指定された [%] をコマンドスクリプトとして実行します。
 c_exit1              = アプリケーションの終了
@@ -514,7 +503,6 @@
 c_show23             = 現在のデータベースセッションを表示します。
 c_show24             = データベースにアクセスできるユーザーを表示します。
 c_show25             = バックアップを表示します。
-c_show26             = イベントを表示します。
 c_store1             = Rawデータを格納します。
 c_store2             = Rawデータを指定された [%] に格納します。
 c_test1              = XQUnit テストを実行します。
diff -Nru basex-8.1.1/basex-core/src/main/resources/lang/Mongolian.lang basex-8.2.3/basex-core/src/main/resources/lang/Mongolian.lang
--- basex-8.1.1/basex-core/src/main/resources/lang/Mongolian.lang	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/resources/lang/Mongolian.lang	2015-07-14 10:54:40.000000000 +0000
@@ -53,7 +53,7 @@
 comment              = Сэтгэгдэл
 community            = Олон нийтийн харилцаа
 compiling            = Хөрвүүлэлт
-connection_error     = Сервертэй холбогдож чадахгүй байна.
+connection_error     = Сервертэй холбогдож чадахгүй байна
 copy                 = Хуулах
 copy_db              = Өгөгдлийн санг хуулах
 copy_path            = Байршил хуулах
@@ -114,13 +114,6 @@
 entries_%            = % оролтууд
 error                = Алдаатай
 evaluating           = Тооцоололт
-event_created_%      = Үйл ажиллагаа(event) '%' үүссэн.
-event_dropped_%      = Үйл ажиллагаа(event) '%' устгагдсан.
-event_exists_%       = Үйл ажиллагаа(event) '%' өмнө үүссэн байна.
-event_not_watched_%  = Үйл ажиллагаа(event) '%' хянаагүй байна.
-event_unknown_%      = Үйл ажиллагаа(event) '%' тодорхойгүй.
-event_watched_%      = Үйл ажиллагаа(event) '%' хянагдсан байна.
-events_%             = % Үйл ажиллагаа(event(s))-үүд
 exec_error_%         = Хөрвүүлэгдэж чадахгүй байна %
 exit                 = Хаах
 expecting_cmd        = Коммандаас гадуур байна.
@@ -277,7 +270,7 @@
 pkg_replaced_%_%     = '%' багц %-нд солигдсон.
 please_wait          = Түр хүлээнэ үү
 plot                 = Схем
-port_twice_%         = Порт '%' нь дахин тодорхойлогдсон байна.
+port                 = Порт
 preferences          = Тохиргоонууд
 printed              = Хэвлэгдсэн
 printing             = Хэвлэлт
@@ -343,9 +336,9 @@
 skipped              = Алгассан
 sort                 = Sort
 split_input_lines    = Мөрүүдэд хуваах
-srv_running          = Серверийн ажиллагаа эсвэл эрх олголт амжилтгүй.
-srv_started_port_%   = Сервер ажиллаж байна (Порт: %)
-srv_stopped_port_%   = Сервер зогссон (Порт: %)
+srv_running          = Серверийн ажиллагаа эсвэл эрх олголт амжилтгүй
+srv_started          = Сервер ажиллаж байна
+srv_stopped          = Сервер зогссон
 standard             = Стандарт
 status_bar           = Статус бар
 stemming             = Зогсоолт
@@ -380,7 +373,6 @@
 unknown_host_x       = Тодорхойлогдоогүй '%' хост байна.
 unknown_option_%     = '%' тодорхойгүй тохиргоо.
 unknown_user_%       = Хэрэглэгч '%' тодорхойгүй.
-unwatching_event_%   = Үйл ажиллагаа(event) '%' хянагдаагүй.
 up_to_date           = Саяхан шинэчлэгдсэн, шинэ
 updated              = Шинэчлэгдсэн
 use_catalog_file     = XML каталог файл ашиглах
@@ -398,7 +390,6 @@
 version              = Хувилбар
 view                 = Харагдах байдал
 visualization        = Visualization
-watching_event_%     = Үйл ажиллагаа(event) '%' хянах.
 whole_word           = Whole Word
 write_locking        = Write Locking
 yes                  = Тийм
@@ -448,7 +439,6 @@
 c_create22           = [%] Нөөцлөх өгөгдлийн санг үүсгэх
 c_create23           = Тодорхойлогдсон индекс үүсгэх
 c_create24           = Тодорхойлогдсон хэрэглэгч үүсгэх
-c_create25           = үйл ажиллагаа (event) үүсгэх
 c_delete1            = Өгөгдлийн сангаас документ устгах.
 c_delete2            = Нээллтэй байгаа өгөгдлийн сангаас документ устгах.
 c_drop1              = Өгөгдлийн сан, хэрэглэгч эсвэл индекс устгах.
@@ -457,7 +447,6 @@
 c_drop22             = Тодорхойлогдсон индексийг устгах
 c_drop23             = Тодорхойлогдсон хэрэглэгчийг устгах (өгөгдлийн сан дах).
 c_drop24             = Өгөгдлийн сангийн нөөцлөлтийг устгах
-c_drop25             = Үйл ажиллагаануудыг устгах
 c_execute1           = Execute command script.
 c_execute2           = Executes the specified [%] as command script.
 c_exit1              = Програмыг хаах.
@@ -514,7 +503,6 @@
 c_show23             = Нээлттэй байгаа өгөгдлийн сангийн суулт(session)-г харуулах.
 c_show24             = Хэрэглэгчдийг харуулах (өгөгдлийн сан дээр).
 c_show25             = Нөөцлөлтийг харуулах.
-c_show26             = Үйл ажиллагааг харуулах.
 c_store1             = Боловсруулалт хийгдээгүй мэдээллийг хадгалах.
 c_store2             = [%]-нд боловсруулалт хийгдээгүй мэдээллийг хадгалах.
 c_test1              = Run XQUnit tests.
diff -Nru basex-8.1.1/basex-core/src/main/resources/lang/Romanian.lang basex-8.2.3/basex-core/src/main/resources/lang/Romanian.lang
--- basex-8.1.1/basex-core/src/main/resources/lang/Romanian.lang	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/resources/lang/Romanian.lang	2015-07-14 10:54:40.000000000 +0000
@@ -53,7 +53,7 @@
 comment              = Observație
 community            = Comunitate
 compiling            = Compilator
-connection_error     = Nu se poate comunica cu serverul.
+connection_error     = Nu se poate comunica cu serverul
 copy                 = Copiaza
 copy_db              = Copiaza baza de date
 copy_path            = Calea de copiere
@@ -114,13 +114,6 @@
 entries_%            = % intrări
 error                = Eroare
 evaluating           = Evaluarea
-event_created_%      = Evenimentul '%' a fost creat.
-event_dropped_%      = Evenimentul '%' a fost sters.
-event_exists_%       = Evenimentul '%' deja există.
-event_not_watched_%  = Evenimentul '%' nu a fost vizualizat.
-event_unknown_%      = Evenimentul '%' este necunoscut.
-event_watched_%      = Deja in curs de vizualizare a evnimentului '%'.
-events_%             = % evenimente
 exec_error_%         = Nu s-a putut executa %
 exit                 = Ieşire
 expecting_cmd        = Astept comanda.
@@ -277,7 +270,7 @@
 pkg_replaced_%_%     = Pachetul '%' înlocuit în %.
 please_wait          = Vă rog să așteptați
 plot                 = Plot
-port_twice_%         = Portul '%' a fost specificat de două ori.
+port                 = portul
 preferences          = Preferințe
 printed              = Tipărit
 printing             = In curs de tipărire
@@ -343,9 +336,9 @@
 skipped              = Trecute peste
 sort                 = Sort
 split_input_lines    = Desparte intrarea în linii
-srv_running          = Serverul este pornit sau permisiunea a fost refuzata.
-srv_started_port_%   = Serverul este pornit (portul: %)
-srv_stopped_port_%   = Serverul a fost oprit (portul: %)
+srv_running          = Serverul este pornit sau permisiunea a fost refuzata
+srv_started          = Serverul este pornit
+srv_stopped          = Serverul a fost oprit
 standard             = Standard
 status_bar           = Bara de stare
 stemming             = Stemming
@@ -380,7 +373,6 @@
 unknown_host_x       = Host necunoscut '%'.
 unknown_option_%     = Opţiune necunoscută '%'.
 unknown_user_%       = Utilizator necunoscut '%'.
-unwatching_event_%   = Eveniment '%' nesupravegheat.
 up_to_date           = La zi
 updated              = Actualizat
 use_catalog_file     = Utilizaţi fişier XML Catalog
@@ -398,7 +390,6 @@
 version              = Versiune
 view                 = Vizualizare
 visualization        = Visualization
-watching_event_%     = Uita-te la evenimentul '%'.
 whole_word           = Cuvantul intreg
 write_locking        = Write Locking
 yes                  = Da
@@ -448,7 +439,6 @@
 c_create22           = Creează o copie de rezervă a bazei de date [%]
 c_create23           = Creează indicele specificat
 c_create24           = Creează utilizatorul specificat
-c_create25           = Creeaza eveniment
 c_delete1            = Ştergeţi resurse din baza de date.
 c_delete2            = Şterge resursele din baza de date în prezent deschise.
 c_drop1              = Sterge baze de date, index, utilizator, copie de rezervă sau eveniment.
@@ -457,7 +447,6 @@
 c_drop22             = Sterge indicele specificat
 c_drop23             = Sterge utilizator specificat (pe o bază de date).
 c_drop24             = Sterge baza de date de rezerva
-c_drop25             = Sterge eveniment
 c_execute1           = Executa command script.
 c_execute2           = Executa [%] specificat ca un command script.
 c_exit1              = Ieşiţi din aplicaţie.
@@ -514,7 +503,6 @@
 c_show23             = prezinta sesiuni de baze de date actuale.
 c_show24             = Afiseaza utilizatorii (unei baze de date).
 c_show25             = Arată backupurile.
-c_show26             = Arată evenimente.
 c_store1             = Stochează date brute.
 c_store2             = Stochează date brute la [%].
 c_test1              = Run XQUnit tests.
diff -Nru basex-8.1.1/basex-core/src/main/resources/lang/Russian.lang basex-8.2.3/basex-core/src/main/resources/lang/Russian.lang
--- basex-8.1.1/basex-core/src/main/resources/lang/Russian.lang	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/resources/lang/Russian.lang	2015-07-14 10:54:40.000000000 +0000
@@ -114,13 +114,6 @@
 entries_%            = Элементов: % 
 error                = Ошибка
 evaluating           = Обработка
-event_created_%      = Событие '%' было создано
-event_dropped_%      = Событие '%' было удалено
-event_exists_%       = Событие '%' уже существует
-event_not_watched_%  = Событие '%' уже не слушается
-event_unknown_%      = Неизвестное событие '%'
-event_watched_%      = Уже слушается событие '%'
-events_%             = Событий: %
 exec_error_%         = Не удалось выполнить %
 exit                 = Выход
 expecting_cmd        = Ожидается команда
@@ -277,7 +270,7 @@
 pkg_replaced_%_%     = Пакет '%' был заменен за %.
 please_wait          = Ожидайте
 plot                 = График
-port_twice_%         = Порт '%' был указан дважды
+port                 = порт
 preferences          = Настройки
 printed              = Выведено
 printing             = Вывод на экран
@@ -344,8 +337,8 @@
 sort                 = Сортировка
 split_input_lines    = Разделять содержимое на строки
 srv_running          = Сервер уже запущен или недостаточно прав для выполнения операции
-srv_started_port_%   = Сервер запущен (порт: %)
-srv_stopped_port_%   = Сервер остановлен (порт: %)
+srv_started          = Сервер запущен
+srv_stopped          = Сервер остановлен
 standard             = Обычный
 status_bar           = Строка статуса
 stemming             = Морфологический поиск
@@ -380,7 +373,6 @@
 unknown_host_x       = Неизвестный хост '%'
 unknown_option_%     = Неизвестный параметр '%'.
 unknown_user_%       = Неизвестный пользователь '%'.
-unwatching_event_%   = Событие '%' перестало слушаться
 up_to_date           = Актуальное состояние
 updated              = Обновлено
 use_catalog_file     = Использовать файл XML каталога
@@ -398,7 +390,6 @@
 version              = Версия
 view                 = Вид
 visualization        = Визуализация
-watching_event_%     = Слушается событие '%'
 whole_word           = Слово целиком
 write_locking        = Блокировка на запись
 yes                  = Да
@@ -448,7 +439,6 @@
 c_create22           = создаст резервную копию базы данных [%]
 c_create23           = создаст индекс указанного типа
 c_create24           = создаст указанного пользователя
-c_create25           = создаст событие
 c_delete1            = Удаление ресурсов из базы данных
 c_delete2            = Удаляет ресурсы в открытой на данный момент базе
 c_drop1              = Удаление резервной копии, базы данных, события, индекса или пользователя
@@ -457,7 +447,6 @@
 c_drop22             = удалит указанный индекс
 c_drop23             = удалит указанного пользователя (в указанной базе данных)
 c_drop24             = удалит резервную копию базы данных
-c_drop25             = удалит событие
 c_execute1           = Выполнение сценария команд
 c_execute2           = Исполняет указанный [%] как сценарий команд
 c_exit1              = Выход из приложения
@@ -514,7 +503,6 @@
 c_show23             = активные сессии текущей базы данных
 c_show24             = список пользователей (указанной базы данных)
 c_show25             = список резервных копий
-c_show26             = список событий
 c_store1             = Сохранить исходный файл
 c_store2             = Сохраняет исходный файл по указанному пути [%]
 c_test1              = Выполнить XQUnit тесты
diff -Nru basex-8.1.1/basex-core/src/main/resources/lang/Spanish.lang basex-8.2.3/basex-core/src/main/resources/lang/Spanish.lang
--- basex-8.1.1/basex-core/src/main/resources/lang/Spanish.lang	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/main/resources/lang/Spanish.lang	2015-07-14 10:54:40.000000000 +0000
@@ -53,7 +53,7 @@
 comment              = Comentario
 community            = Comunidad
 compiling            = Compilando
-connection_error     = No se puede comunicar con el servidor.
+connection_error     = No se puede comunicar con el servidor
 copy                 = Copiar
 copy_db              = Copiar Base de Datos
 copy_path            = Copiar Ruta
@@ -114,13 +114,6 @@
 entries_%            = % entradas
 error                = Error
 evaluating           = Evaluando
-event_created_%      = El evento '%' ha sido creado.
-event_dropped_%      = El evento '%' ha sido borrado.
-event_exists_%       = El evento '%' ya existe.
-event_not_watched_%  = No se ha monitorizado el evento '%'.
-event_unknown_%      = El evento '%' es desconocido.
-event_watched_%      = Ya se está monitorizando el evento '%'.
-events_%             = % evento(s)
 exec_error_%         = No se pudo ejecutar %
 exit                 = Salir
 expecting_cmd        = Esperando comando.
@@ -277,7 +270,7 @@
 pkg_replaced_%_%     = Paquete '%' reemplazado en %.
 please_wait          = Por favor, espere
 plot                 = Diagrama
-port_twice_%         = El puerto '%' se ha especificado dos veces.
+port                 = puerto
 preferences          = Preferencias
 printed              = Impreso
 printing             = Imprimiendo
@@ -344,8 +337,8 @@
 sort                 = Ordenar
 split_input_lines    = Separar salida en varias líneas
 srv_running          = El servidor está ejecutándose o el permiso fue denegado
-srv_started_port_%   = El servidor ha arrancado (puerto: %)
-srv_stopped_port_%   = El servidor ha parado (puerto: %)
+srv_started          = El servidor ha arrancado
+srv_stopped          = El servidor ha parado
 standard             = Estándar
 status_bar           = Barra de estado
 stemming             = Reducción a la raíz
@@ -380,7 +373,6 @@
 unknown_host_x       = Host desconocido '%'.
 unknown_option_%     = Opción desconocida '%'.
 unknown_user_%       = Usuario desconocido '%'.
-unwatching_event_%   = Evento '%' no monitorizado.
 up_to_date           = Actualizado
 updated              = Actualizado
 use_catalog_file     = Utilizar el fichero XML de Catálogo
@@ -398,7 +390,6 @@
 version              = Versión
 view                 = Vista
 visualization        = Visualización
-watching_event_%     = Monitorizar evento '%'.
 whole_word           = Palabra Entera
 write_locking        = Bloqueo de Escritura
 yes                  = Sí
@@ -448,7 +439,6 @@
 c_create22           = crea la copia de seguridad de la Base de Datos [%]
 c_create23           = crea el índice especificado
 c_create24           = crea el usuario especificado
-c_create25           = crea el evento
 c_delete1            = Borrar recursos de la Base de Datos.
 c_delete2            = Borra recursos de la Base de Datos abierta.
 c_drop1              = Borrar una Base de Datos, índice, usuario, copia de seguridad o evento.
@@ -457,7 +447,6 @@
 c_drop22             = Borra el índice especificado
 c_drop23             = Borra el usuario especificado (de una Base de Datos).
 c_drop24             = Borra la copia de seguridad de la Base de Datos
-c_drop25             = borra el evento
 c_execute1           = Ejecuta un conjunto de comandos.
 c_execute2           = Ejecuta lo especificado [%] como un conjunto de comandos.
 c_exit1              = Sale de la aplicación.
@@ -514,7 +503,6 @@
 c_show23             = muestra las sesiones de la Base de Datos actual.
 c_show24             = muestra usuarios (de una Base de Datos).
 c_show25             = muestra copias de seguridad.
-c_show26             = muestra eventos.
 c_store1             = Almacena datos en bruto.
 c_store2             = Almacena datos en bruto en la [%] especificada.
 c_test1              = Ejecutar los tests XQUnit.
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/build/CollectionPathTest.java basex-8.2.3/basex-core/src/test/java/org/basex/build/CollectionPathTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/build/CollectionPathTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/build/CollectionPathTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -58,7 +58,7 @@
       "where $x//location contains text 'uzbekistan' " +
       "return $x";
     try(final QueryProcessor qp = new QueryProcessor(find, context)) {
-      assertEquals(1, qp.execute().size());
+      assertEquals(1, qp.value().size());
     }
   }
 
@@ -70,7 +70,7 @@
   public void findDocs() throws Exception {
     final String find = "collection('" + NAME + "/test/zipped') ";
     try(final QueryProcessor qp = new QueryProcessor(find, context)) {
-      assertEquals(4, qp.execute().size());
+      assertEquals(4, qp.value().size());
     }
   }
 
@@ -82,7 +82,7 @@
   public void baseUri() throws Exception {
     final String find = "base-uri(collection('" + NAME + '/' + DIR + "xmark.xml'))";
     try(final QueryProcessor qp = new QueryProcessor(find, context)) {
-      assertEquals(NAME + '/' + FILES[1], qp.execute().toString());
+      assertEquals(NAME + '/' + FILES[1], qp.value().serialize().toString());
     }
   }
 }
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/build/CreateTest.java basex-8.2.3/basex-core/src/test/java/org/basex/build/CreateTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/build/CreateTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/build/CreateTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -157,6 +157,6 @@
    * @return first document name
    */
   private static String docName() {
-    return Token.string(context.data().text(context.current().pres[0], true));
+    return Token.string(context.data().text(context.current().pre(0), true));
   }
 }
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/build/PathTest.java basex-8.2.3/basex-core/src/test/java/org/basex/build/PathTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/build/PathTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/build/PathTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -63,7 +63,7 @@
   public void documentTestInput() throws Exception {
     final String count = "count(collection('" + INPUT + "/input'))";
     try(final QueryProcessor qp = new QueryProcessor(count, context)) {
-      assertEquals(1, Integer.parseInt(qp.execute().toString()));
+      assertEquals(1, Integer.parseInt(qp.value().serialize().toString()));
     }
   }
 
@@ -75,7 +75,7 @@
   public void documentTestWeek() throws Exception {
     final String count = "count(collection('" + WEEK1 + "/week/monday'))";
     try(final QueryProcessor qp = new QueryProcessor(count, context)) {
-      assertEquals(3, Integer.parseInt(qp.execute().toString()));
+      assertEquals(3, Integer.parseInt(qp.value().serialize().toString()));
     }
   }
 
@@ -100,7 +100,7 @@
     path.write(Token.token("<a/>"));
     context.options.set(MainOptions.PARSER, MainParser.JSON);
     try(final QueryProcessor qp = new QueryProcessor("doc('" + path + "')", context)) {
-      assertEquals("<a/>", qp.execute().toString());
+      assertEquals("<a/>", qp.value().serialize().toString());
     }
   }
 
@@ -125,13 +125,13 @@
     final String count = "count(collection('" + WEEK1 +
       "/week/monday')/root/monday/text[text() = 'text'])";
     try(final QueryProcessor qp = new QueryProcessor(count, context)) {
-      assertEquals(3, Integer.parseInt(qp.execute().toString()));
+      assertEquals(3, Integer.parseInt(qp.value().serialize().toString()));
     }
     // cross-check
     final String count2 = "count(collection('" + WEEK1 +
       "/week')/root/monday/text[text() = 'text'])";
     try(final QueryProcessor qp2 = new QueryProcessor(count2, context)) {
-      assertEquals(4, Integer.parseInt(qp2.execute().toString()));
+      assertEquals(4, Integer.parseInt(qp2.value().serialize().toString()));
     }
   }
 
@@ -144,7 +144,7 @@
       " count(collection('" + WEEK2 +
       "/week/tuesday')/root/monday/text[text() = 'text']) ";
     try(final QueryProcessor qp = new QueryProcessor(count, context)) {
-      assertEquals("3\n1", normNL(qp.execute()));
+      assertEquals("3\n1", normNL(qp.value().serialize().toString()));
     }
   }
 }
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/core/CommandLockingTest.java basex-8.2.3/basex-core/src/test/java/org/basex/core/CommandLockingTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/core/CommandLockingTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/core/CommandLockingTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -47,8 +47,6 @@
   private static final StringList BACKUP_LIST = new StringList(DBLocking.BACKUP);
   /** StringList containing BACKUP lock string and name. */
   private static final StringList BACKUP_NAME = new StringList(DBLocking.BACKUP, NAME);
-  /** StringList containing EVENT lock string. */
-  private static final StringList EVENT_LIST = new StringList(DBLocking.EVENT);
   /** StringList containing java module test lock strings. */
   private static final StringList MODULE_LIST = new StringList(DBLocking.MODULE_PREFIX
       + QueryModuleTest.LOCK1, DBLocking.MODULE_PREFIX + QueryModuleTest.LOCK2);
@@ -66,14 +64,12 @@
     ckDBs(new Copy(NAME2, NAME), new StringList(NAME2), NAME_LIST);
     ckDBs(new CreateBackup(NAME), NAME_LIST, BACKUP_LIST);
     ckDBs(new CreateDB(NAME), CTX_LIST, NAME_LIST);
-    ckDBs(new CreateEvent(NAME), true, EVENT_LIST);
     ckDBs(new CreateIndex(IndexType.TEXT), true, CTX_LIST);
     ckDBs(new CreateUser(NAME, NAME), true, ADMIN_LIST);
     ckDBs(new Delete(FILE), true, CTX_LIST);
     ckDBs(new DropBackup(NAME), true, BACKUP_LIST);
     ckDBs(new DropDB(NAME + '*'), true, null); // Drop using globbing
     ckDBs(new DropDB(NAME), true, NAME_LIST);
-    ckDBs(new DropEvent(NAME), true, EVENT_LIST);
     ckDBs(new DropIndex(IndexType.TEXT), true, CTX_LIST);
     ckDBs(new DropUser(NAME), true, ADMIN_LIST);
     ckDBs(new Execute("RUN " + FILE), true, null);
@@ -107,7 +103,6 @@
     ckDBs(new Run(FILE), true, null);
     ckDBs(new Set(NAME, NAME), false, NONE);
     ckDBs(new ShowBackups(), false, BACKUP_LIST);
-    ckDBs(new ShowEvents(), false, EVENT_LIST);
     ckDBs(new ShowSessions(), false, NONE);
     ckDBs(new ShowUsers(), false, ADMIN_LIST);
     ckDBs(new ShowUsers(NAME), false, ADMIN_LIST);
@@ -124,6 +119,14 @@
     // fn:collection() always accesses the global context, no matter what local context is
     ckDBs(new XQuery("<a/>/" + COUNT.args(COLLECTION.args())), false, CTX_LIST);
     ckDBs(new XQuery(DOC.args(NAME)), false, NAME_LIST);
+    ckDBs(new XQuery(ID.args(NAME)), false, CTX_LIST);
+    ckDBs(new XQuery(IDREF.args(NAME)), false, CTX_LIST);
+    ckDBs(new XQuery(ELEMENT_WITH_ID.args(NAME)), false, CTX_LIST);
+    ckDBs(new XQuery(LANG.args(NAME)), false, CTX_LIST);
+    ckDBs(new XQuery(ID.args(NAME, DOC.args(NAME))), false, NAME_LIST);
+    ckDBs(new XQuery(IDREF.args(NAME, DOC.args(NAME))), false, NAME_LIST);
+    ckDBs(new XQuery(ELEMENT_WITH_ID.args(NAME, DOC.args(NAME))), false, NAME_LIST);
+    ckDBs(new XQuery(LANG.args(NAME, DOC.args(NAME))), false, NAME_LIST);
     ckDBs(new XQuery(DOC_AVAILABLE.args(NAME + "/foo.xml")), false, NAME_LIST, null);
     ckDBs(new XQuery(PARSE_XML.args("<foo/>")), true, NONE);
     ckDBs(new XQuery(PARSE_XML_FRAGMENT.args("<foo/>")), true, NONE);
@@ -205,7 +208,6 @@
     // General Functions
     ckDBs(new XQuery(_DB_INFO.args(NAME)), false, NAME_LIST);
     ckDBs(new XQuery(_DB_LIST.args(NAME)), false, NAME_LIST);
-    ckDBs(new XQuery(_DB_INFO.args()), false, null);
     ckDBs(new XQuery(_DB_LIST_DETAILS.args(NAME)), false, NAME_LIST);
     ckDBs(new XQuery(_DB_LIST_DETAILS.args()), false, null);
     ckDBs(new XQuery(_DB_OPEN.args(NAME)), false, NAME_LIST);
@@ -245,8 +247,6 @@
     ckDBs(new XQuery(_DB_IS_RAW.args(NAME, FILE)), false, NAME_LIST);
     ckDBs(new XQuery(_DB_IS_XML.args(NAME, FILE)), false, NAME_LIST);
     ckDBs(new XQuery(_DB_CONTENT_TYPE.args(NAME, FILE)), false, NAME_LIST);
-    ckDBs(new XQuery(_DB_EVENT.args("foo", "bar")), false, NONE);
-    ckDBs(new XQuery(_DB_EVENT.args("foo", DOC.args(NAME))), false, NAME_LIST);
   }
 
   /** Test ft module. */
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/core/CommandTest.java basex-8.2.3/basex-core/src/test/java/org/basex/core/CommandTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/core/CommandTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/core/CommandTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -413,6 +413,20 @@
     ok(new Rename(FILE, "xxx"));
     // source need not exist
     ok(new Rename(FILE, "xxx"));
+
+    // check leading and trailing slashes
+    ok(new CreateDB(NAME));
+    ok(new Add("x.xml", "<x/>"));
+    ok(new Rename("x.xml", "y.xml"));
+    assertEquals(NAME + "/y.xml", ok(new XQuery("base-uri(.)")));
+    ok(new Rename("/", "a/"));
+    assertEquals(NAME + "/a/y.xml", ok(new XQuery("base-uri(.)")));
+    ok(new Rename("a/", "/"));
+    assertEquals(NAME + "/y.xml", ok(new XQuery("base-uri(.)")));
+    ok(new Rename("/", "a"));
+    assertEquals(NAME + "/a/y.xml", ok(new XQuery("base-uri(.)")));
+    ok(new Rename("a", "/"));
+    assertEquals(NAME + "/y.xml", ok(new XQuery("base-uri(.)")));
   }
 
   /** Command test. */
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/core/LocalConcurrencyTest.java basex-8.2.3/basex-core/src/test/java/org/basex/core/LocalConcurrencyTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/core/LocalConcurrencyTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/core/LocalConcurrencyTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -39,7 +39,7 @@
             try(Session session = new LocalSession(context, "user", "")) {
               session.execute(new Open("store"));
               counter.incrementAndGet();
-            } catch(Exception ex) {
+            } catch(final Exception ex) {
               error[0] = ex;
             }
           }
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/core/LockingTest.java basex-8.2.3/basex-core/src/test/java/org/basex/core/LockingTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/core/LockingTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/core/LockingTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -64,6 +64,21 @@
   }
 
   /**
+   * Single thread acquires both global read lock and a single write lock.
+   * @throws InterruptedException Got interrupted.
+   */
+  @Test
+  public void singleThreadGlobalReadLocalWriteTest() throws InterruptedException {
+    final CountDownLatch test = new CountDownLatch(1);
+    final LockTester th1 = new LockTester(null, null, objects, test);
+
+    th1.start();
+    assertTrue("Thread should be able to acquire lock.",
+        test.await(WAIT, TimeUnit.MILLISECONDS));
+    th1.release();
+  }
+
+  /**
    * Test for concurrent writes.
    * @throws InterruptedException Got interrupted.
    */
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/core/XMLCommandTest.java basex-8.2.3/basex-core/src/test/java/org/basex/core/XMLCommandTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/core/XMLCommandTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/core/XMLCommandTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -42,8 +42,6 @@
     ok("<create-db name='X'>X</create-db>");
     ok("<create-db name='X'><X/></create-db>");
 
-    ok("<create-event name='X'/>");
-
     ok("<create-index type='X'/>");
 
     ok("<create-user name='X'/>");
@@ -55,8 +53,6 @@
 
     ok("<drop-db name='X'/>");
 
-    ok("<drop-event name='X'/>");
-
     ok("<drop-index type='X'/>");
 
     ok("<drop-user name='X' pattern='X'/>");
@@ -73,6 +69,7 @@
 
     ok("<flush/>");
 
+    ok("<get/>");
     ok("<get option='X'/>");
 
     ok("<grant name='X' permission='X' pattern='X'/>");
@@ -126,8 +123,6 @@
 
     ok("<show-backups/>");
 
-    ok("<show-events/>");
-
     ok("<show-sessions/>");
 
     ok("<show-users/>");
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/data/IndexTest.java basex-8.2.3/basex-core/src/test/java/org/basex/data/IndexTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/data/IndexTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/data/IndexTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -21,6 +21,7 @@
    */
   @After
   public void after() throws BaseXException {
+    run(new Close());
     run(new Set(MainOptions.UPDINDEX, false));
     run(new Set(MainOptions.AUTOOPTIMIZE, false));
   }
@@ -141,7 +142,19 @@
     run(new Close());
     run(new Open(NAME));
     run(new Delete("A"));
-    run(new Close());
+  }
+
+  /**
+   * Test.
+   * @throws BaseXException database exception
+   */
+  @Test
+  public void updindex8() throws BaseXException {
+    run(new Set(MainOptions.UPDINDEX, true));
+    run(new CreateDB(NAME));
+    run(new Replace("A", "<X a='?' b='a' c='1'/>"));
+    run(new Replace("A", "<X a='?' b='b' c='2'/>"));
+    run(new Replace("A", "<X/>"));
   }
 
   /**
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/data/UpdateTestAttributes.java basex-8.2.3/basex-core/src/test/java/org/basex/data/UpdateTestAttributes.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/data/UpdateTestAttributes.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/data/UpdateTestAttributes.java	2015-07-14 10:54:40.000000000 +0000
@@ -4,7 +4,6 @@
 
 import java.io.*;
 
-import org.basex.data.atomic.*;
 import org.basex.util.*;
 import org.junit.*;
 
@@ -63,7 +62,7 @@
     final long nextid = data.meta.lastid;
 
     final MemData md = new MemData(context.data(), context.options);
-    md.attr(0, 1, data.attrNames.index(T_FOO, null, false), T_JUNIT, 0, false);
+    md.attr(0, 1, data.attrNames.index(T_FOO, null, false), T_JUNIT, 0);
     md.insert(0);
     data.startUpdate(context.options);
     data.insertAttr(9, 6, new DataClip(md));
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/data/UpdateTestTags.java basex-8.2.3/basex-core/src/test/java/org/basex/data/UpdateTestTags.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/data/UpdateTestTags.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/data/UpdateTestTags.java	2015-07-14 10:54:40.000000000 +0000
@@ -4,7 +4,6 @@
 
 import java.io.*;
 
-import org.basex.data.atomic.*;
 import org.basex.util.*;
 import org.junit.*;
 
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/data/UpdateTestText.java basex-8.2.3/basex-core/src/test/java/org/basex/data/UpdateTestText.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/data/UpdateTestText.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/data/UpdateTestText.java	2015-07-14 10:54:40.000000000 +0000
@@ -4,7 +4,6 @@
 
 import java.io.*;
 
-import org.basex.data.atomic.*;
 import org.junit.*;
 
 /**
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/io/parse/json/JsonParserTest.java basex-8.2.3/basex-core/src/test/java/org/basex/io/parse/json/JsonParserTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/io/parse/json/JsonParserTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/io/parse/json/JsonParserTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -146,19 +146,6 @@
   }
 
   /**
-   * Tests for parsing constructors.
-   * @throws QueryIOException query I/O exception
-   */
-  @Test public void constructorTest() throws QueryIOException {
-    parse("new foo()", true);
-    parse("new Test(1, { })", true);
-    parse("new Foo([ { \"a\": new Test(1, { }) } ])", true);
-
-    error("new" , true);
-    error("newt", true);
-  }
-
-  /**
    * Tests if the given JSON string is rejected by the parser using the given spec.
    * @param json JSON string
    * @param liberal liberal parsing
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/io/parse/json/JsonStringConverter.java basex-8.2.3/basex-core/src/test/java/org/basex/io/parse/json/JsonStringConverter.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/io/parse/json/JsonStringConverter.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/io/parse/json/JsonStringConverter.java	2015-07-14 10:54:40.000000000 +0000
@@ -54,7 +54,7 @@
   }
 
   @Override
-  public void openPair(final byte[] key) {
+  public void openPair(final byte[] key, final boolean add) {
     if(!first) tb.add(", ");
     stringLit(key);
     tb.add(": ");
@@ -92,27 +92,6 @@
   }
 
   @Override
-  public void openConstr(final byte[] name) {
-    tb.add("new ").add(name).add('(');
-    first = true;
-  }
-
-  @Override
-  public void openArg() {
-    openItem();
-  }
-
-  @Override
-  public void closeArg() {
-    closeItem();
-  }
-
-  @Override
-  public void closeConstr() {
-    tb.add(')');
-  }
-
-  @Override
   public void numberLit(final byte[] value) {
     tb.add(value);
   }
@@ -160,7 +139,7 @@
 
   @Override
   public void nullLit() {
-    tb.add(Token.NULL);
+    tb.add(JsonConstants.NULL);
   }
 
   @Override
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/query/AdvancedQueryTest.java basex-8.2.3/basex-core/src/test/java/org/basex/query/AdvancedQueryTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/query/AdvancedQueryTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/query/AdvancedQueryTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -163,9 +163,9 @@
     try(final QueryProcessor qp = new QueryProcessor(query, context)) {
       qp.sc.baseURI(BASEURI);
       try(final Serializer ser = qp.getSerializer(ao)) {
-        qp.execute().serialize(ser);
+        qp.value().serialize(ser);
       }
     }
-    return normNL(ao);
+    return normNL(ao.toString());
   }
 }
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/query/ast/GFLWOROptimizeTest.java basex-8.2.3/basex-core/src/test/java/org/basex/query/ast/GFLWOROptimizeTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/query/ast/GFLWOROptimizeTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/query/ast/GFLWOROptimizeTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -256,4 +256,14 @@
         "exists(//Let)"
     );
   }
+
+  /** Checks that clauses can be removed during inlining. */
+  @Test public void gh1150() {
+    check("for $i in 1 to xs:integer(random:double()) let $x := 'does-not-exist.xml' "
+        + "for $x in doc($x) let $x := count($x) return $x",
+        "",
+        "count(//For) eq 1",
+        "count(//GFLWOR/*) eq 2",
+        "starts-with(//GFLWOR/*[last()]/@name, 'error(')");
+  }
 }
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/query/ast/InlineTest.java basex-8.2.3/basex-core/src/test/java/org/basex/query/ast/InlineTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/query/ast/InlineTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/query/ast/InlineTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -133,4 +133,14 @@
         + "let $b := $a(1) let $c := $a(1) let $d := $a(1) return $b", "1", "count(//Let) != 2");
     check("let $a := 'foo' return 'bar' ! . ! $a", "foo", "empty(//Let)");
   }
+
+  /** Checks that window clauses are recognized as loops. */
+  @Test public void gh1126() {
+    check("let $s := (1 to 2) ! . "
+        + "for tumbling window $w in 1 to 2 start when true() end when true() return $s",
+        "1\n2\n1\n2",
+        "count(//Let) eq 1",
+        "count(//Window) eq 1",
+        "//Let << //Window");
+  }
 }
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/query/ast/QueryPlanTest.java basex-8.2.3/basex-core/src/test/java/org/basex/query/ast/QueryPlanTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/query/ast/QueryPlanTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/query/ast/QueryPlanTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -28,7 +28,7 @@
       // retrieve compiled query plan
       final FDoc plan = qp.plan();
       // compare results
-      if(res != null) assertEquals(res, normNL(qp.execute()));
+      if(res != null) assertEquals(res, normNL(qp.value().serialize().toString()));
 
       for(final String p : pr) {
         if(new QueryProcessor(p, context).context(plan).value() != Bln.TRUE) {
@@ -36,7 +36,7 @@
               "- Plan: " + plan.serialize());
         }
       }
-    } catch(final QueryException | QueryIOException ex) {
+    } catch(final Exception ex) {
       final AssertionError err = new AssertionError(Util.message(ex));
       err.initCause(ex);
       throw err;
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/query/ast/RewritingsTest.java basex-8.2.3/basex-core/src/test/java/org/basex/query/ast/RewritingsTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/query/ast/RewritingsTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/query/ast/RewritingsTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -190,6 +190,21 @@
     check("<a/>[" + STRING_LENGTH.args() + " gt 1]", "", "exists(//" + stringLength + ")");
 
     check("<a/>[" + STRING_LENGTH.args() + " = <a>1</a>]", "", "exists(//" + stringLength + ")");
+  }
+
+  /**
+   * Checks that empty sequences are eliminated from lists and that singleton lists are flattened.
+   */
+  @Test
+  public void list() {
+    check("((), <x/>, ())", "<x/>", "empty(//List)", "empty(//Empty)", "exists(/*/CElem)");
+  }
 
+  /**
+   * Checks that expressions marked as non-deterministic will not be rewritten.
+   */
+  @Test
+  public void nonDeterministic() {
+    check("count((# basex:non-deterministic #) { <x/> })", "1", "exists(//FnCount)");
   }
 }
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/query/expr/PackageAPITest.java basex-8.2.3/basex-core/src/test/java/org/basex/query/expr/PackageAPITest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/query/expr/PackageAPITest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/query/expr/PackageAPITest.java	2015-07-14 10:54:40.000000000 +0000
@@ -49,7 +49,7 @@
     for(final IOFile f : new IOFile(REPO).children()) {
       if(f.isDir() && f.name().contains(".")) f.delete();
     }
-    context = newContext();
+    context = new Context();
     context.soptions.set(StaticOptions.REPOPATH, REPO);
   }
 
@@ -204,16 +204,16 @@
 
   /**
    * Tests ability to import two modules from the same package.
-   * @throws QueryException query exception
+   * @throws Exception exception
    */
   @Test
-  public void importTwoModulesFromPkg() throws QueryException {
+  public void importTwoModulesFromPkg() throws Exception {
     try(final QueryProcessor qp = new QueryProcessor(
       "import module namespace ns1='ns1';" +
       "import module namespace ns3='ns3';" +
       "(ns1:test2() eq 'pkg2mod1') and (ns3:test() eq 'pkg2mod2')",
       context)) {
-      assertEquals(qp.execute().toString(), "true");
+      assertEquals(qp.value().serialize().toString(), "true");
     }
   }
 
@@ -248,11 +248,10 @@
 
   /**
    * Tests installing of a package containing a jar file.
-   * @throws BaseXException database exception
-   * @throws QueryException query exception
+   * @throws Exception exception
    */
   @Test
-  public void installJar() throws BaseXException, QueryException {
+  public void installJar() throws Exception {
     // install package
     new RepoInstall(REPO + "testJar.xar", null).execute(context);
 
@@ -268,7 +267,7 @@
     // use package
     try(final QueryProcessor qp = new QueryProcessor(
         "import module namespace j='jar'; j:print('test')", context)) {
-      assertEquals(qp.execute().toString(), "test");
+      assertEquals(qp.value().serialize().toString(), "test");
     }
 
     // delete package
@@ -277,19 +276,19 @@
 
   /**
    * Tests usage of installed packages.
-   * @throws QueryException query exception
+   * @throws Exception exception
    */
   @Test
-  public void importPkg() throws QueryException {
+  public void importPkg() throws Exception {
     // try with a package without dependencies
     try(final QueryProcessor qp = new QueryProcessor(
         "import module namespace ns3='ns3'; ns3:test()", context)) {
-      assertEquals(qp.execute().toString(), "pkg2mod2");
+      assertEquals(qp.value().serialize().toString(), "pkg2mod2");
     }
     // try with a package with dependencies
     try(final QueryProcessor qp = new QueryProcessor(
         "import module namespace ns2='ns2'; ns2:test()", context)) {
-      assertEquals(qp.execute().toString(), "pkg2mod2");
+      assertEquals(qp.value().serialize().toString(), "pkg2mod2");
     }
   }
 
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/query/FTIndexQueryTest.java basex-8.2.3/basex-core/src/test/java/org/basex/query/FTIndexQueryTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/query/FTIndexQueryTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/query/FTIndexQueryTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -23,9 +23,9 @@
    * @throws BaseXException database exception
    */
   private static void init(final String input) throws BaseXException {
-    new CreateDB(NAME, input).execute(SandboxTest.context);
-    new Set(MainOptions.FTINDEX, true).execute(SandboxTest.context);
-    new CreateDB(NAME + "ix", input).execute(SandboxTest.context);
+    new CreateDB(NAME, input).execute(Sandbox.context);
+    new Set(MainOptions.FTINDEX, true).execute(Sandbox.context);
+    new CreateDB(NAME + "ix", input).execute(Sandbox.context);
   }
 
   /**
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/query/func/AdminModuleTest.java basex-8.2.3/basex-core/src/test/java/org/basex/query/func/AdminModuleTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/query/func/AdminModuleTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/query/func/AdminModuleTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -56,7 +56,7 @@
   @Test
   public void deleteLogs() {
     // no logging data exists in the sandbox
-    error(_ADMIN_DELETE_LOGS.args(Log.name(new Date())), BXCA_TODAY);
+    error(_ADMIN_DELETE_LOGS.args(Log.name(new Date())), BXAD_TODAY);
     error(_ADMIN_DELETE_LOGS.args("2001-01-01"), WHICHRES_X);
   }
 }
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/query/func/ArchiveModuleTest.java basex-8.2.3/basex-core/src/test/java/org/basex/query/func/ArchiveModuleTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/query/func/ArchiveModuleTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/query/func/ArchiveModuleTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -18,33 +18,32 @@
   private static final String ZIP = "src/test/resources/xml.zip";
   /** Test GZIP file. */
   private static final String GZIP = "src/test/resources/xml.gz";
+  /** Test file. */
+  private static final String DIR = "src/test/resources/dir";
 
   /** Test method. */
   @Test
   public void create() {
     // simple zip files
-    query(COUNT.args(_ARCHIVE_CREATE.args("X", "")), "1");
+    count(_ARCHIVE_CREATE.args("X", ""), 1);
+
     // simple zip files
-    query(COUNT.args(_ARCHIVE_CREATE.args("<archive:entry>X</archive:entry>", "")), "1");
-    query(COUNT.args(_ARCHIVE_CREATE.args(
-        "<archive:entry level='9'>X</archive:entry>", "")), "1");
-    query(COUNT.args(_ARCHIVE_CREATE.args(
-        "<archive:entry encoding='US-ASCII'>X</archive:entry>", "")),
-        "1");
-    query(COUNT.args(_ARCHIVE_CREATE.args("<archive:entry " +
-        "last-modified='2000-01-01T12:12:12'>X</archive:entry>", "")), "1");
-    query(COUNT.args(_ARCHIVE_CREATE.args("<archive:entry>X</archive:entry>", "",
-        " map { }")), "1");
-    query(COUNT.args(_ARCHIVE_CREATE.args("<archive:entry>X</archive:entry>", "",
-        " map { 'format':'zip', 'algorithm':'deflate' }")), "1");
-    query(COUNT.args(_ARCHIVE_CREATE.args("X", "", "<archive:options/>")), "1");
-    query(COUNT.args(_ARCHIVE_CREATE.args("<archive:entry>X</archive:entry>", "",
+    count(_ARCHIVE_CREATE.args("<archive:entry>X</archive:entry>", ""), 1);
+    count(_ARCHIVE_CREATE.args("<archive:entry level='9'>X</archive:entry>", ""), 1);
+    count(_ARCHIVE_CREATE.args("<archive:entry encoding='US-ASCII'>X</archive:entry>", ""), 1);
+    count(_ARCHIVE_CREATE.args("<archive:entry " +
+        "last-modified='2000-01-01T12:12:12'>X</archive:entry>", ""), 1);
+    count(_ARCHIVE_CREATE.args("<archive:entry>X</archive:entry>", "", " map { }"), 1);
+    count(_ARCHIVE_CREATE.args("<archive:entry>X</archive:entry>", "",
+        " map { 'format':'zip', 'algorithm':'deflate' }"), 1);
+    count(_ARCHIVE_CREATE.args("X", "", "<archive:options/>"), 1);
+    count(_ARCHIVE_CREATE.args("<archive:entry>X</archive:entry>", "",
         "<archive:options><archive:format value='zip'/>" +
-        "<archive:algorithm value='deflate'/></archive:options>")), "1");
-    query(COUNT.args(_ARCHIVE_CREATE.args("<archive:entry>X</archive:entry>", "",
-        "<archive:options><archive:format value='zip'/></archive:options>")), "1");
-    query(COUNT.args(_ARCHIVE_CREATE.args("<archive:entry>X</archive:entry>", "",
-        "<archive:options><archive:format value='gzip'/></archive:options>")), "1");
+        "<archive:algorithm value='deflate'/></archive:options>"), 1);
+    count(_ARCHIVE_CREATE.args("<archive:entry>X</archive:entry>", "",
+        "<archive:options><archive:format value='zip'/></archive:options>"), 1);
+    count(_ARCHIVE_CREATE.args("<archive:entry>X</archive:entry>", "",
+        "<archive:options><archive:format value='gzip'/></archive:options>"), 1);
 
     // different number of entries and contents
     error(_ARCHIVE_CREATE.args("X", "()"), ARCH_DIFF_X_X);
@@ -73,29 +72,41 @@
     error(_ARCHIVE_CREATE.args("<archive:entry>X</archive:entry>", "", " map { 'x':'y' }"),
         INVALIDOPT_X);
     error(_ARCHIVE_CREATE.args("<archive:entry>X</archive:entry>", "",
-        "<archive:options><archive:format value='rar'/></archive:options>"),
-        ARCH_UNKNOWN);
+        "<archive:options><archive:format value='rar'/></archive:options>"), ARCH_UNKNOWN);
     // algorithm not supported
     error(_ARCHIVE_CREATE.args("<archive:entry>X</archive:entry>", "",
-        "<archive:options><archive:algorithm value='unknown'/></archive:options>"),
-        ARCH_SUPP_X_X);
+        "<archive:options><archive:algorithm value='unknown'/></archive:options>"), ARCH_SUPP_X_X);
     // algorithm not supported
     error(_ARCHIVE_CREATE.args("('x','y')", "('a','b')",
-        "<archive:options><archive:format value='gzip'/></archive:options>"),
-        ARCH_ONE_X);
+        "<archive:options><archive:format value='gzip'/></archive:options>"), ARCH_ONE_X);
+  }
+
+  /** Test method. */
+  @Test
+  public void createFrom() {
+    count(_ARCHIVE_CREATE_FROM.args(DIR), 4);
+    count(_ARCHIVE_CREATE_FROM.args(DIR, " map { }"), 4);
+    count(_ARCHIVE_CREATE_FROM.args(DIR, " map { 'algorithm': 'stored' }"), 4);
+    query(PARSE_XML.args(_ARCHIVE_EXTRACT_TEXT.args(_ARCHIVE_CREATE_FROM.args(DIR, " map { }"),
+        "input.xml")) + " instance of document-node()", "true");
+
+    // errors
+    error(_ARCHIVE_CREATE_FROM.args("UNUNUNKNOWN"), FILE_NO_DIR_X);
+    error(_ARCHIVE_CREATE_FROM.args(DIR, " map { }", "UNUNUNKNOWN"), FILE_NOT_FOUND_X);
+    error(_ARCHIVE_CREATE_FROM.args(DIR, " map { }", "."), FILE_IS_DIR_X);
   }
 
   /** Test method. */
   @Test
   public void entries() {
     // read entries
-    query(COUNT.args(_ARCHIVE_ENTRIES.args(_FILE_READ_BINARY.args(ZIP))), "5");
+    query(COUNT.args(_ARCHIVE_ENTRIES.args(_FILE_READ_BINARY.args(ZIP))), 5);
     // simple zip files
     query(COUNT.args(_ARCHIVE_ENTRIES.args(_FILE_READ_BINARY.args(ZIP)) +
-        "[@size][@last-modified][@compressed-size]"), "5");
+        "[@size][@last-modified][@compressed-size]"), 5);
     // simple gzip files
     query(COUNT.args(_ARCHIVE_ENTRIES.args(_FILE_READ_BINARY.args(GZIP)) +
-        "[not(@size)][not(@last-modified)][not(@compressed-size)][not(text())]"), "1");
+        "[not(@size)][not(@last-modified)][not(@compressed-size)][not(text())]"), 1);
   }
 
   /** Test method. */
@@ -112,7 +123,7 @@
   @Test
   public void extractText() {
     // extract all entries
-    query(COUNT.args(_ARCHIVE_EXTRACT_TEXT.args(_FILE_READ_BINARY.args(ZIP))), "5");
+    query(COUNT.args(_ARCHIVE_EXTRACT_TEXT.args(_FILE_READ_BINARY.args(ZIP))), 5);
     // extract all entries
     query("let $a := " + _FILE_READ_BINARY.args(ZIP) +
           "let $b := " + _ARCHIVE_ENTRIES.args("$a") +
@@ -134,7 +145,7 @@
   @Test
   public void extractBinary() {
     // extract all entries
-    query(COUNT.args(_ARCHIVE_EXTRACT_BINARY.args(_FILE_READ_BINARY.args(ZIP))), "5");
+    query(COUNT.args(_ARCHIVE_EXTRACT_BINARY.args(_FILE_READ_BINARY.args(ZIP))), 5);
     // extract all entries
     query("let $a := " + _FILE_READ_BINARY.args(ZIP) +
           "let $b := " + _ARCHIVE_ENTRIES.args("$a") +
@@ -156,6 +167,26 @@
 
   /** Test method. */
   @Test
+  public void extractTo() {
+    // write archive and count number of entries
+    final String tmp = new IOFile(sandbox(), "tmp").path();
+    query(_ARCHIVE_EXTRACT_TO.args(tmp, _FILE_READ_BINARY.args(ZIP)));
+    count(_FILE_READ_BINARY.args(ZIP), 5);
+    // write archive and count number of entries
+    query(_ARCHIVE_EXTRACT_TO.args(tmp, _FILE_READ_BINARY.args(ZIP),
+        _ARCHIVE_ENTRIES.args(_FILE_READ_BINARY.args(ZIP))));
+    count(_FILE_READ_BINARY.args(ZIP), 5);
+
+    query("let $a := " + _ARCHIVE_ENTRIES.args(
+      _FILE_READ_BINARY.args(ZIP)) + "/string() " +
+      "let $f := " + _FILE_LIST.args(tmp, "true()") + '[' +
+      _FILE_IS_FILE.args(" '" + tmp + "/'||.") + "] ! replace(., '\\\\', '/') " +
+      "return (every $e in $a satisfies $e = $f) and (every $e in $f satisfies $e =$ a)",
+      "true");
+  }
+
+  /** Test method. */
+  @Test
   public void update() {
     // add a new entry
     query(_FILE_READ_BINARY.args(ZIP) + " ! " +
@@ -197,23 +228,12 @@
         _ARCHIVE_DELETE.args(" .", "X"), ARCH_MODIFY_X);
   }
 
-  /** Test method. */
-  @Test
-  public void write() {
-    // write archive and count number of entries
-    final String tmp = new IOFile(sandbox(), "tmp").path();
-    query(_ARCHIVE_WRITE.args(tmp, _FILE_READ_BINARY.args(ZIP)));
-    query(COUNT.args(_ARCHIVE_ENTRIES.args(_FILE_READ_BINARY.args(ZIP))), "5");
-    // write archive and count number of entries
-    query(_ARCHIVE_WRITE.args(tmp, _FILE_READ_BINARY.args(ZIP),
-        _ARCHIVE_ENTRIES.args(_FILE_READ_BINARY.args(ZIP))));
-    query(COUNT.args(_ARCHIVE_ENTRIES.args(_FILE_READ_BINARY.args(ZIP))), "5");
-
-    query("let $a := " + _ARCHIVE_ENTRIES.args(
-      _FILE_READ_BINARY.args(ZIP)) + "/string() " +
-      "let $f := " + _FILE_LIST.args(tmp, "true()") + '[' +
-      _FILE_IS_FILE.args(" '" + tmp + "/'||.") + "] ! replace(., '\\\\', '/') " +
-      "return (every $e in $a satisfies $e = $f) and (every $e in $f satisfies $e =$ a)",
-      "true");
+  /**
+   * Counts the entries of an archive.
+   * @param archive archive
+   * @param exp expected number of results
+   */
+  private void count(final String archive, final int exp) {
+    query(COUNT.args(_ARCHIVE_ENTRIES.args(archive)), exp);
   }
 }
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/query/func/DbModuleTest.java basex-8.2.3/basex-core/src/test/java/org/basex/query/func/DbModuleTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/query/func/DbModuleTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/query/func/DbModuleTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -189,7 +189,7 @@
     query(xmlCall + "/@raw/data()", "false");
     query(xmlCall + "/@content-type/data()", MediaType.APPLICATION_XML.toString());
     query(xmlCall + "/@modified-date/xs:dateTime(.)");
-    query(xmlCall + "/@size/data()", "");
+    query(xmlCall + "/@size/data()", "2");
     query(xmlCall + "/text()", "xml");
 
     final String rawCall = _DB_LIST_DETAILS.args(NAME, "raw");
@@ -212,6 +212,7 @@
     new CreateBackup(NAME).execute(context);
     query(COUNT.args(_DB_BACKUPS.args()), "1");
     query(COUNT.args(_DB_BACKUPS.args(NAME)), "1");
+    query(COUNT.args(_DB_BACKUPS.args(NAME) + "/(@database, @date, @size)"), "3");
     query(COUNT.args(_DB_BACKUPS.args(NAME + 'X')), "0");
     new DropBackup(NAME).execute(context);
     query(COUNT.args(_DB_BACKUPS.args(NAME)), "0");
@@ -246,12 +247,6 @@
 
   /** Test method. */
   @Test
-  public void event() {
-    error(_DB_EVENT.args("X", "Y"), BXDB_EVENT_X);
-  }
-
-  /** Test method. */
-  @Test
   public void output() {
     query(_DB_OUTPUT.args("x"), "x");
     query(_DB_OUTPUT.args("('x','y')"), "x\ny");
@@ -263,6 +258,13 @@
 
   /** Test method. */
   @Test
+  public void outputCache() {
+    query(_DB_OUTPUT_CACHE.args(), "");
+    query(_DB_OUTPUT.args("x") + ',' + _DB_OUTPUT.args(_DB_OUTPUT_CACHE.args()), "x\nx");
+  }
+
+  /** Test method. */
+  @Test
   public void add() {
     query(COUNT.args(COLLECTION.args(NAME)), "1");
     query(_DB_ADD.args(NAME, FILE));
@@ -687,6 +689,7 @@
   public void path() {
     query(_DB_PATH.args(_DB_OPEN.args(NAME)), FILE.replaceAll(".*/", ""));
     query(_DB_PATH.args(_DB_OPEN.args(NAME) + "/*"), FILE.replaceAll(".*/", ""));
+    query(_DB_PATH.args("<x/> update ()"), "");
   }
 
   /**
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/query/func/FileModuleTest.java basex-8.2.3/basex-core/src/test/java/org/basex/query/func/FileModuleTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/query/func/FileModuleTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/query/func/FileModuleTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -124,6 +124,13 @@
 
   /** Test method. */
   @Test
+  public void isAbsolute() {
+    query(_FILE_IS_ABSOLUTE.args(PATH), true);
+    query(_FILE_IS_ABSOLUTE.args("a"), false);
+  }
+
+  /** Test method. */
+  @Test
   public void isFile() {
     query(_FILE_IS_FILE.args(PATH), false);
     query(_FILE_WRITE.args(PATH1, "()"));
@@ -426,9 +433,15 @@
   @Test
   public void resolvePath() {
     final String path = query(_FILE_RESOLVE_PATH.args(PATH1));
-    final String can = Paths.get(PATH1).normalize().toAbsolutePath().toString();
-    assertEquals(path, can);
+    final String can1 = Paths.get(PATH1).normalize().toAbsolutePath().toString();
+    final String can2 = Paths.get(PATH2).normalize().toAbsolutePath().toString();
+    assertEquals(path, can1);
     query(ENDS_WITH.args(_FILE_RESOLVE_PATH.args("."), File.separator), "true");
+
+    query(CONTAINS.args(_FILE_RESOLVE_PATH.args(can1, can2), can1), "true");
+    query(CONTAINS.args(_FILE_RESOLVE_PATH.args("X", can1), can1 + File.separator + "X"), "true");
+    error(_FILE_RESOLVE_PATH.args(can1, "b"), FILE_IS_RELATIVE_X);
+    error(_FILE_RESOLVE_PATH.args("X", "b"), FILE_IS_RELATIVE_X);
   }
 
   /** Test method. */
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/query/func/fn/FnFormatNumberTest.java basex-8.2.3/basex-core/src/test/java/org/basex/query/func/fn/FnFormatNumberTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/query/func/fn/FnFormatNumberTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/query/func/fn/FnFormatNumberTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -42,7 +42,7 @@
       { "formnum  10", strings("0"), "format-number(0, '0')" },
       { "formnum  20", strings("00"), "format-number(0, '10')" },
       { "formnum  30", strings("1"), "format-number(1, '0')" },
-      { "formnum  35", strings("0.1"), "format-number(0.1, '.0')" },
+      { "formnum  35", strings(".1"), "format-number(0.1, '.0')" },
       { "formnum  40", strings("1.0"), "format-number(1, '1.0')" },
       { "formnum  50", strings("1"), "format-number(1.1, '1')" },
       { "formnum  60", strings("1.1"), "format-number(1.1, '1.0')" },
@@ -73,7 +73,14 @@
         "format-number(xs:decimal('11111111111111111111'), '#,#')" },
       { "formnum 300", strings("12.346e2"), "format-number(1234.5678, '00.000e0')" },
 
-      // http://www.w3schools.com/XSL/func_formatnumber.asp
+      { "formnum 310", strings("\u0a66,i"),
+          "declare default decimal-format zero-digit = '&#xA66;';"
+        + "format-number(0, '#,i')" },
+      { "formnum 320", strings("\u0a67"),
+          "declare default decimal-format zero-digit = '&#xA66;';"
+        + "format-number(1, '#\u0a66')" },
+
+        // http://www.w3schools.com/XSL/func_formatnumber.asp
       { "formnum w3-10", strings("500100"), "format-number(500100, '#')" },
       { "formnum w3-20", strings("500100"), "format-number(500100, '0')" },
       { "formnum w3-30", strings("500100.00"), "format-number(500100, '#.00')" },
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/query/func/fn/FnTest.java basex-8.2.3/basex-core/src/test/java/org/basex/query/func/fn/FnTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/query/func/fn/FnTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/query/func/fn/FnTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -34,12 +34,25 @@
 
   /** Test method. */
   @Test
+  public void jsonToXml() {
+    contains(JSON_TO_XML.args("null"), "xmlns");
+    contains(JSON_TO_XML.args("null") + " update ()", "xmlns");
+  }
+
+  /** Test method. */
+  @Test
   public void serialize() {
     contains(SERIALIZE.args("<x/>"), "<x/>");
     contains(SERIALIZE.args("<x/>", serialParams("")), "<x/>");
     contains(SERIALIZE.args("<x>a</x>", serialParams("<method value='text'/>")), "a");
   }
 
+  /** Test method. */
+  @Test
+  public void parseSubstring() {
+    contains(SUBSTRING.args("'ab'", " [2]"), "b");
+  }
+
   /** Tests for the {@code replace} function. */
   @Test
   public void replace() {
@@ -65,6 +78,14 @@
     error("sum((), (1,2))", SEQFOUND_X);
   }
 
+  /** Tests for the {@code static-base-uri} function. */
+  @Test
+  public void staticBaseURI() {
+    query("declare base-uri 'a/'; " + ENDS_WITH.args(STATIC_BASE_URI.args(), "/"), "true");
+    query("declare base-uri '.'; " + ENDS_WITH.args(STATIC_BASE_URI.args(), "/"), "true");
+    query("declare base-uri '..'; " + ENDS_WITH.args(STATIC_BASE_URI.args(), "/"), "true");
+  }
+
   /** Tests for the {@code parse-ietf-date} function. */
   @Test
   public void parseIetfDate() {
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/query/func/FtModuleTest.java basex-8.2.3/basex-core/src/test/java/org/basex/query/func/FtModuleTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/query/func/FtModuleTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/query/func/FtModuleTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -223,5 +223,7 @@
     query("declare ft-option using stemming; " + _FT_NORMALIZE.args("Gifts"), "gift");
     query(_FT_NORMALIZE.args(""), "");
     query(_FT_NORMALIZE.args("a!b:c"), "a!b:c");
+
+    query("ft:normalize('&#778;', map { 'stemming': true(), 'language': 'de' })", "");
   }
 }
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/query/func/InspectModuleTest.java basex-8.2.3/basex-core/src/test/java/org/basex/query/func/InspectModuleTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/query/func/InspectModuleTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/query/func/InspectModuleTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -48,9 +48,11 @@
     query(func + "/return/@type/data()", "xs:integer");
     query(func + "/return/@occurrence/data()", "");
 
-    // unknown annotations disappear
-    query("declare namespace x='x';" +
-      _INSPECT_FUNCTION.args(" %x:x function() {()}") + "/annotation", "");
+    // unknown annotation
+    query("declare namespace pref='uri';" +
+      _INSPECT_FUNCTION.args(" %pref:x function() {()}") + "/annotation/@name/data()", "pref:x");
+    query("declare namespace pref='uri';" +
+        _INSPECT_FUNCTION.args(" %pref:x function() {()}") + "/annotation/@uri/data()", "uri");
   }
 
   /** Test method. */
@@ -59,18 +61,26 @@
     error(_INSPECT_MODULE.args("src/test/resources/non-existent.xqm"), WHICHRES_X);
 
     final String module = "src/test/resources/hello.xqm";
-    final String result = query(_INSPECT_MODULE.args(module));
+    final String result = query(_INSPECT_MODULE.args(module)).
+        replace("{", "{{").replace("}", "}}");
+
     final String var = query(result + "/variable[@name = 'hello:lazy']");
     query(var + "/@uri/data()", "world");
     query(var + "/annotation/@name/data()", "basex:lazy");
     query(var + "/annotation/@uri/data()", "http://basex.org");
 
-    final String func = query(result + "/function[@name = 'hello:world']");
-    query(func + "/@uri/data()", "world");
-    query(func + "/annotation/@name/data()", "public");
-    query(func + "/annotation/@uri/data()", "http://www.w3.org/2012/xquery");
-    query(func + "/return/@type/data()", "xs:string");
-    query(func + "/return/@occurrence/data()", "");
+    final String func1 = query(result + "/function[@name = 'hello:world']");
+    query(func1 + "/@uri/data()", "world");
+    query(func1 + "/annotation/@name/data()", "public");
+    query(func1 + "/annotation/@uri/data()", "http://www.w3.org/2012/xquery");
+    query(func1 + "/return/@type/data()", "xs:string");
+    query(func1 + "/return/@occurrence/data()", "");
+
+    final String func2 = query(result + "/function[@name = 'hello:internal']").
+        replace("{", "{{").replace("}", "}}");;
+    query(func2 + "/@uri/data()", "world");
+    query(func2 + "/annotation/@name/data()[ends-with(., 'ignored')]", "ignored");
+    query(func2 + "/annotation/@uri/data()[. = 'ns']", "ns");
   }
 
   /** Test method. */
@@ -79,7 +89,8 @@
     error(_INSPECT_XQDOC.args("src/test/resources/non-existent.xqm"), WHICHRES_X);
 
     // validate against xqDoc schema
-    final String result = query(_INSPECT_XQDOC.args("src/test/resources/hello.xqm"));
+    final String result = query(_INSPECT_XQDOC.args("src/test/resources/hello.xqm")).
+        replace("{", "{{").replace("}", "}}");
     query(_VALIDATE_XSD.args(result, "src/test/resources/xqdoc.xsd"));
   }
 
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/query/func/WebModuleTest.java basex-8.2.3/basex-core/src/test/java/org/basex/query/func/WebModuleTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/query/func/WebModuleTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/query/func/WebModuleTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -73,4 +73,22 @@
     query(_WEB_RESPONSE_HEADER.args(" map { }", " map { 'Cache-Control': '' }") +
         "/*:response/*:header", "");
   }
+
+  /** Test method. */
+  @Test
+  public void encodeUrl() {
+    query(_WEB_ENCODE_URL.args("a&#xd; *-._"), "a%0D+*-._");
+  }
+
+  /** Test method. */
+  @Test
+  public void decodeUrl() {
+    query(_WEB_DECODE_URL.args("a+-._*"), "a -._*");
+    query("let $s := codepoints-to-string((9, 10, 13, 32 to 55295, 57344 to 65533, 65536)) " +
+        "return $s = web:decode-url(web:encode-url($s))", "true");
+
+    error(_WEB_DECODE_URL.args("%1"), BXWE_INVALID_X);
+    error(_WEB_DECODE_URL.args("%1F"), BXWE_CODES_X);
+    error(_WEB_DECODE_URL.args("%D8%00"), BXWE_CODES_X);
+  }
 }
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/query/IndexOptimizeTest.java basex-8.2.3/basex-core/src/test/java/org/basex/query/IndexOptimizeTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/query/IndexOptimizeTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/query/IndexOptimizeTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -258,7 +258,7 @@
     String plan = null;
     try {
       try(QueryProcessor qp = new QueryProcessor(query, context)) {
-        final String string = qp.execute().serialize();
+        final String string = qp.value().serialize().toString();
         if(result != null) assertEquals(result, normNL(string));
 
         // fetch query plan
@@ -269,7 +269,7 @@
       try(QueryProcessor qp = new QueryProcessor(plan + "/descendant-or-self::*" +
             "[self::" + Util.className(ValueAccess.class) +
             "|self::" + Util.className(FTIndexAccess.class) + ']', context)) {
-        final String string = qp.execute().serialize();
+        final String string = qp.value().serialize().toString();
         assertFalse("No index used:\n- Query: " + query + "\n- Plan: " + plan + "\n- " +
             qp.info().trim(), string.isEmpty());
       }
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/query/ModuleTest.java basex-8.2.3/basex-core/src/test/java/org/basex/query/ModuleTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/query/ModuleTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/query/ModuleTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -5,6 +5,8 @@
 import org.basex.*;
 import org.basex.core.cmd.*;
 import org.basex.io.*;
+import org.basex.query.util.*;
+import org.basex.query.value.item.*;
 import org.basex.util.*;
 import org.junit.Test;
 
@@ -23,7 +25,7 @@
   public void builtIn() throws Exception {
     final String query = "import module namespace xquery = 'http://basex.org/modules/xquery'; 1";
     try(final QueryProcessor qp = new QueryProcessor(query, context)) {
-      qp.execute();
+      qp.value();
     }
   }
 
@@ -81,4 +83,22 @@
       qc.parseMain("import module namespace a='a'; ()", null, null);
     }
   }
+
+  /**
+   * Uses a URI resolver.
+   * @throws Exception exception
+   */
+  @Test
+  public void uriResolver() throws Exception {
+    final String query = "import module namespace m='uri' at 'x.xq'; m:f()";
+    try(final QueryProcessor qp = new QueryProcessor(query, context)) {
+      qp.uriResolver(new UriResolver() {
+        @Override
+        public IO resolve(final String path, final String uri, final Uri base) {
+          return new IOContent("module namespace m='uri'; declare function m:f() { 'OK' };");
+        }
+      });
+      assertEquals(qp.value().serialize().toString(), "OK");
+    }
+  }
 }
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/query/NamespaceTest.java basex-8.2.3/basex-core/src/test/java/org/basex/query/NamespaceTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/query/NamespaceTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/query/NamespaceTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -7,6 +7,7 @@
 
 import org.basex.core.*;
 import org.basex.core.cmd.*;
+import org.basex.data.*;
 import org.basex.io.*;
 import org.basex.io.serial.*;
 import org.basex.query.up.primitives.node.*;
@@ -60,8 +61,8 @@
     create(12);
     query("insert node <b xmlns:ns='A'/> into doc('d12')/*:a/*:b");
     assertEquals(NL +
-        "  Pre[3] xmlns:ns=\"A\" " + NL +
-        "  Pre[4] xmlns=\"B\" ",
+        "  Pre[3] xmlns:ns=\"A\"" + NL +
+        "  Pre[4] xmlns=\"B\"",
         context.data().nspaces.toString());
   }
 
@@ -75,7 +76,7 @@
     create(13);
     query("insert node <c/> as first into doc('d13')/a");
     assertEquals(NL +
-        "  Pre[3] xmlns=\"A\" ",
+        "  Pre[3] xmlns=\"A\"",
         context.data().nspaces.toString());
   }
 
@@ -89,10 +90,10 @@
     create(14);
     query("insert node <n xmlns='D'/> into doc('d14')/*:a/*:b");
     assertEquals(NL +
-        "  Pre[1] xmlns=\"A\" " + NL +
-        "    Pre[2] xmlns=\"B\" " + NL +
-        "      Pre[3] xmlns=\"D\" " + NL +
-        "    Pre[4] xmlns=\"C\" ",
+        "  Pre[1] xmlns=\"A\"" + NL +
+        "    Pre[2] xmlns=\"B\"" + NL +
+        "      Pre[3] xmlns=\"D\"" + NL +
+        "    Pre[4] xmlns=\"C\"",
         context.data().nspaces.toString());
   }
 
@@ -106,7 +107,7 @@
     create(12);
     query("delete node doc('d12')/a/b");
     assertEquals(NL +
-        "  Pre[2] xmlns=\"B\" ",
+        "  Pre[2] xmlns=\"B\"",
         context.data().nspaces.toString());
   }
 
@@ -120,8 +121,8 @@
     create(14);
     query("delete node doc('d14')/*:a/*:b");
     assertEquals(NL +
-        "  Pre[1] xmlns=\"A\" " + NL +
-        "    Pre[2] xmlns=\"C\" ",
+        "  Pre[1] xmlns=\"A\"" + NL +
+        "    Pre[2] xmlns=\"C\"",
         context.data().nspaces.toString());
   }
 
@@ -135,9 +136,9 @@
     create(15);
     query("delete node doc('d15')/*:a/*:c");
     assertEquals(NL +
-        "  Pre[1] xmlns=\"A\" " + NL +
-        "    Pre[2] xmlns=\"B\" " + NL +
-        "    Pre[3] xmlns=\"E\" ",
+        "  Pre[1] xmlns=\"A\"" + NL +
+        "    Pre[2] xmlns=\"B\"" + NL +
+        "    Pre[3] xmlns=\"E\"",
         context.data().nspaces.toString());
   }
 
@@ -154,6 +155,23 @@
   }
 
   /**
+   * Inserts an attribute with namespace.
+   * @throws Exception exception
+   */
+  @Test
+  public void insertAttributeWithNs() throws Exception {
+    create(1);
+    query("insert node attribute { QName('ns', 'pref:local') } { } into /*");
+    final Data data = context.data();
+    assertEquals(false, data.nsFlag(0));
+    assertEquals(true, data.nsFlag(1));
+    assertEquals(false, data.nsFlag(2));
+    assertEquals(0, data.uriId(1, data.kind(1)));
+    assertEquals(1, data.uriId(2, data.kind(2)));
+    assertEquals("ns", string(data.nspaces.uri(1)));
+  }
+
+  /**
    * Tests for correct namespace hierarchy, esp. if namespace nodes
    * on the following axis of an insert/delete operation are
    * updated correctly.
@@ -176,7 +194,7 @@
     create(21);
     query("delete node //b");
     assertEquals(NL +
-        "  Pre[2] xmlns:p1=\"u1\" ",
+        "  Pre[2] xmlns:p1=\"u1\"",
         context.data().nspaces.toString());
   }
 
@@ -264,9 +282,9 @@
     create(9);
     query("insert node <f xmlns='F'/> into doc('d9')//*:e");
     assertEquals(NL +
-        "  Pre[1] xmlns=\"A\" " + NL +
-        "    Pre[4] xmlns=\"D\" " + NL +
-        "    Pre[6] xmlns=\"F\" ",
+        "  Pre[1] xmlns=\"A\"" + NL +
+        "    Pre[4] xmlns=\"D\"" + NL +
+        "    Pre[6] xmlns=\"F\"",
         context.data().nspaces.toString());
   }
 
@@ -279,10 +297,10 @@
     create(10);
     query("insert node <f xmlns='F'/> into doc('d10')//*:e");
     assertEquals(NL +
-        "  Pre[1] xmlns=\"A\" " + NL +
-        "    Pre[4] xmlns=\"D\" " + NL +
-        "      Pre[5] xmlns=\"G\" " + NL +
-        "    Pre[7] xmlns=\"F\" ",
+        "  Pre[1] xmlns=\"A\"" + NL +
+        "    Pre[4] xmlns=\"D\"" + NL +
+        "      Pre[5] xmlns=\"G\"" + NL +
+        "    Pre[7] xmlns=\"F\"",
         context.data().nspaces.toString());
   }
 
@@ -301,8 +319,8 @@
     create(2);
     query("insert node <a xmlns='y'/> into doc('d2')//*:x");
     assertEquals(NL +
-        "  Pre[1] xmlns=\"xx\" " + NL +
-        "    Pre[2] xmlns=\"y\" ",
+        "  Pre[1] xmlns=\"xx\"" + NL +
+        "    Pre[2] xmlns=\"y\"",
         context.data().nspaces.toString());
   }
 
@@ -482,7 +500,7 @@
     context.data().startUpdate(context.options);
     context.data().delete(0);
     context.data().finishUpdate(context.options);
-    final byte[] ns = context.data().nspaces.globalNS();
+    final byte[] ns = context.data().nspaces.globalUri();
     assertTrue(ns != null && ns.length == 0);
   }
 
@@ -630,7 +648,7 @@
     query(
       "let $b := <a xmlns:x='X' x:id='0'/> " +
       "return insert node $b//@*:id into /*:n");
-    assertEquals(1, context.data().ns(1).size());
+    assertEquals(1, context.data().namespaces(1).size());
   }
 
   /** Handles duplicate prefixes. */
@@ -747,7 +765,7 @@
         "  $target := $input-context/works[1]/employee[1]" +
         "return insert nodes $source into $target";
     try(final QueryProcessor qp = new QueryProcessor(query, context)) {
-      qp.execute();
+      qp.value();
     } catch(final QueryException ex) {
       assertEquals("XUTY0004", string(ex.qname().local()));
     }
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/query/ParallelQueryTest.java basex-8.2.3/basex-core/src/test/java/org/basex/query/ParallelQueryTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/query/ParallelQueryTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/query/ParallelQueryTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -40,11 +40,11 @@
   /**
    * Runs a single query.
    * @return result
-   * @throws QueryException exception
+   * @throws Exception exception
    */
-  private static String query() throws QueryException {
+  private static String query() throws Exception {
     try(final QueryProcessor qp = new QueryProcessor(QUERY, context)) {
-      return qp.value().toString();
+      return qp.value().serialize().toString();
     }
   }
 
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/query/QueryTest.java basex-8.2.3/basex-core/src/test/java/org/basex/query/QueryTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/query/QueryTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/query/QueryTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -44,9 +44,9 @@
           String s = correct && cmp.size() != 1 ? "#" + cmp.size() : "";
           sb.append("\n[E" + s + "] ");
           if(correct) {
-            final String cp = cmp.toString();
+            final String cp = cmp.serialize().toString();
             sb.append('\'');
-            sb.append(cp.length() > 1000 ? cp.substring(0, 1000) + "..." : cp);
+            sb.append(cp.length() > 5000 ? cp.substring(0, 5000) + "..." : cp);
             sb.append('\'');
           } else {
             sb.append("error");
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/query/SerializerTest.java basex-8.2.3/basex-core/src/test/java/org/basex/query/SerializerTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/query/SerializerTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/query/SerializerTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -5,7 +5,7 @@
 import org.junit.*;
 
 /**
- * This class tests serializer.
+ * This class tests the serializers.
  *
  * @author BaseX Team 2005-15, BSD License
  * @author Christian Gruen
@@ -25,7 +25,10 @@
     query(option + "<html/>", "<html></html>");
     final String[] empties = { "area", "base", "br", "col", "embed", "hr", "img", "input",
         "link", "meta", "basefont", "frame", "isindex", "param" };
-    for(final String e : empties) query(option + '<' + e + "/>", '<' + e + " />");
+    for(final String e : empties) {
+      query(option + "<html xmlns='http://www.w3.org/1999/xhtml'><" + e + "/></html>",
+          "<html xmlns=\"http://www.w3.org/1999/xhtml\">\n<" + e + " />\n</html>");
+    }
   }
 
   /** Test: method=html. */
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/query/simple/SimpleTest.java basex-8.2.3/basex-core/src/test/java/org/basex/query/simple/SimpleTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/query/simple/SimpleTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/query/simple/SimpleTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -158,6 +158,11 @@
       { "Catch 6", integers(1),
         "declare function local:f($x) { try { 1 idiv $x } catch * { 1 } }; local:f(0)" },
 
+      { "NodeTest 1", strings("a"),
+        "let $d as document-node(element()) := parse-xml('<!--a--><a/>') return name($d/*)" },
+      { "NodeTest 2", strings("a"),
+        "let $d as document-node(element(a)) := parse-xml('<!--a--><a/>') return name($d/*)" },
+
       { "FuncTest 1", integers(1), "xquery version '1.0';" +
         "declare function local:foo() { count(local:bar()) };" +
         "declare function local:bar() { 42 };" +
@@ -196,6 +201,11 @@
       { "Map 3", strings("a", "b"), "<a><b/></a>/b ! ancestor-or-self::node() ! name()" },
 
       { "Constructor 1", strings("1"), "<n xmlns='u'>{attribute{'a'}{1}}</n>/@a/string()" },
+
+      // #1140
+      { "Pred 1", empty(), "declare function local:test() {" +
+          "for $n in (1, 1) return <_><c/><w/></_>/*[$n[1]] }; local:test()/self::w" },
+      { "Pred 2", empty(), "for $n in (2,2) return (<c><c0/></c>, <d><d0/><d2/></d>)/*[$n[$n]]" }
     };
   }
 }
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/query/up/AtomicUpdatesTest.java basex-8.2.3/basex-core/src/test/java/org/basex/query/up/AtomicUpdatesTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/query/up/AtomicUpdatesTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/query/up/AtomicUpdatesTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -7,9 +7,9 @@
 
 import org.basex.build.*;
 import org.basex.data.*;
-import org.basex.data.atomic.*;
 import org.basex.io.*;
 import org.basex.query.*;
+import org.basex.query.up.atomic.*;
 import org.basex.util.*;
 import org.junit.*;
 import org.junit.rules.*;
@@ -527,7 +527,7 @@
    */
   private static DataClip clipA(final Data d, final String name, final String value) {
     final int s = d.meta.size;
-    d.attr(s, s + 1, d.attrNames.index(token(name), null, false), token(value), -1, false);
+    d.attr(s, s + 1, d.attrNames.index(token(name), null, false), token(value), -1);
     d.insert(s);
     return new DataClip(d, s, d.meta.size);
   }
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/query/up/UpdateTest.java basex-8.2.3/basex-core/src/test/java/org/basex/query/up/UpdateTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/query/up/UpdateTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/query/up/UpdateTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -6,9 +6,9 @@
 
 import org.basex.core.*;
 import org.basex.core.cmd.*;
-import org.basex.data.atomic.*;
 import org.basex.io.*;
 import org.basex.query.*;
+import org.basex.query.up.atomic.*;
 import org.basex.query.up.primitives.node.*;
 import org.junit.*;
 import org.junit.Test;
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/query/value/array/ArrayBuilderTest.java basex-8.2.3/basex-core/src/test/java/org/basex/query/value/array/ArrayBuilderTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/query/value/array/ArrayBuilderTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/query/value/array/ArrayBuilderTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -25,7 +25,7 @@
       final Array arr = builder.freeze();
       arr.checkInvariants();
       assertEquals(len, arr.arraySize());
-      final Iterator<Value> iter = arr.members();
+      final Iterator<Value> iter = arr.iterator(0);
       for(int i = 0; i < len; i++) {
         assertTrue(iter.hasNext());
         assertEquals(i, ((Int) iter.next()).itr());
@@ -43,7 +43,7 @@
       final Array arr = builder.freeze();
       arr.checkInvariants();
       assertEquals(len, arr.arraySize());
-      final Iterator<Value> iter = arr.members();
+      final Iterator<Value> iter = arr.iterator(0);
       for(int i = 0; i < len; i++) {
         assertTrue(iter.hasNext());
         assertEquals(i, ((Int) iter.next()).itr());
@@ -77,7 +77,7 @@
       final Array arr = builder.freeze();
       arr.checkInvariants();
       assertEquals(len, arr.arraySize());
-      final Iterator<Value> iter = arr.members();
+      final Iterator<Value> iter = arr.iterator(0);
       for(int i = 0; i < len; i++) {
         assertTrue(iter.hasNext());
         assertEquals(i, ((Int) iter.next()).itr());
@@ -113,7 +113,7 @@
       arr.checkInvariants();
       assertEquals(len, arr.arraySize());
       final Iterator<Integer> iter1 = deque.iterator();
-      final Iterator<Value> iter2 = arr.members();
+      final Iterator<Value> iter2 = arr.iterator(0);
       while(iter1.hasNext()) {
         assertTrue(iter2.hasNext());
         assertEquals(iter1.next().intValue(), ((Int) iter2.next()).itr());
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/query/value/array/ArrayConcatTest.java basex-8.2.3/basex-core/src/test/java/org/basex/query/value/array/ArrayConcatTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/query/value/array/ArrayConcatTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/query/value/array/ArrayConcatTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -17,9 +17,10 @@
 public final class ArrayConcatTest {
   /** Generates and concatenates random arrays of a given size. */
   @Test public void fuzzyTest() {
-    final Random rng = new Random(42);
-    for(int n = 0; n < 1000; n++) {
+    final Random rng = new Random();
+    for(int n = 0; n < 1_000; n++) {
       for(int k = 0; k < 10; k++) {
+        rng.setSeed(10 * n + k);
         final int l = rng.nextInt(n + 1), r = n - l;
 
         Array a1 = Array.empty(), b1 = Array.empty();
@@ -42,7 +43,7 @@
         assertEquals(n, a1.arraySize());
         assertEquals(n, a2.size());
 
-        final Iterator<Value> it1 = a1.members();
+        final Iterator<Value> it1 = a1.iterator(0);
         final Iterator<Integer> it2 = a2.iterator();
         while(it1.hasNext()) {
           assertTrue(it2.hasNext());
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/query/value/array/ArrayMembersTest.java basex-8.2.3/basex-core/src/test/java/org/basex/query/value/array/ArrayMembersTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/query/value/array/ArrayMembersTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/query/value/array/ArrayMembersTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -9,7 +9,7 @@
 import org.junit.*;
 
 /**
- * Tests for {@link Array#members(boolean)}.
+ * Tests for {@link Array#iterator(long)}.
  *
  * @author BaseX Team 2005-15, BSD License
  * @author Leo Woerteler
@@ -17,8 +17,8 @@
 public final class ArrayMembersTest {
   /** Random movements inside the array. */
   @Test public void randomTest() {
-    final Random rng = new Random(1337);
     for(int n = 0; n < 1_000; n++) {
+      final Random rng = new Random(1337 + n);
       Array arr = Array.empty();
       final ArrayList<Integer> list = new ArrayList<>(n);
       for(int i = 0; i < n; i++) {
@@ -27,9 +27,10 @@
         list.add(insPos, i);
       }
 
-      final ListIterator<Value> it1 = arr.members();
-      final ListIterator<Integer> it2 = list.listIterator();
-      int pos = 0;
+      final int startPos = rng.nextInt(n + 1);
+      final ListIterator<Value> it1 = arr.iterator(startPos);
+      final ListIterator<Integer> it2 = list.listIterator(startPos);
+      int pos = startPos;
       for(int i = 0; i < 100; i++) {
         final int k = rng.nextInt(n + 1);
         if(rng.nextBoolean()) {
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/query/value/array/ArrayRemoveTest.java basex-8.2.3/basex-core/src/test/java/org/basex/query/value/array/ArrayRemoveTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/query/value/array/ArrayRemoveTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/query/value/array/ArrayRemoveTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -66,7 +66,7 @@
     for(int k = 0; k < n; k++) {
       for(int i = 0; i < k; i++) {
         final Array arr2 = arr.remove(i);
-        final Iterator<Value> iter = arr2.members();
+        final Iterator<Value> iter = arr2.iterator(0);
         for(int j = 0; j < k - 1; j++) {
           assertTrue(iter.hasNext());
           assertEquals(j < i ? j : j + 1, ((Int) iter.next()).itr());
@@ -240,7 +240,7 @@
     final ArrayList<Value> list = new ArrayList<>(n);
     for(int i = 0; i < n; i++) list.add(Int.get(i));
 
-    Array arr = Array.from(list);
+    Array arr = Array.from(list.toArray(new Value[list.size()]));
 
     final Random rng = new Random(42);
     for(int i = 0; i < n; i++) {
@@ -279,7 +279,7 @@
    * @throws AssertionError of the check fails
    */
   private static void assertContains(final Array arr, final int... vals) {
-    final Iterator<Value> iter = arr.members();
+    final Iterator<Value> iter = arr.iterator(0);
     for(final int v : vals) {
       assertTrue(iter.hasNext());
       assertEquals(v, ((Int) iter.next()).itr());
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/query/value/array/ArrayReverseTest.java basex-8.2.3/basex-core/src/test/java/org/basex/query/value/array/ArrayReverseTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/query/value/array/ArrayReverseTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/query/value/array/ArrayReverseTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -22,9 +22,9 @@
       Array arr = Array.empty();
       for(int i = 0; i < n; i++) arr = arr.insertBefore(rng.nextInt(i + 1), Int.get(i));
       assertEquals(n, arr.arraySize());
-      final Array rev = arr.reverse();
-      final ListIterator<Value> af = arr.members(false), ab = arr.members(true);
-      final ListIterator<Value> rf = rev.members(false), rb = rev.members(true);
+      final Array rev = arr.reverseArray();
+      final ListIterator<Value> af = arr.iterator(0), ab = arr.iterator(n);
+      final ListIterator<Value> rf = rev.iterator(0), rb = rev.iterator(n);
       for(int i = 0; i < n; i++) {
         assertTrue(af.hasNext());
         assertTrue(ab.hasPrevious());
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/query/value/array/ArraySliceTest.java basex-8.2.3/basex-core/src/test/java/org/basex/query/value/array/ArraySliceTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/query/value/array/ArraySliceTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/query/value/array/ArraySliceTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -26,7 +26,7 @@
           final Array sub = arr.subArray(pos, k);
           assertEquals(k, sub.arraySize());
           sub.checkInvariants();
-          final Iterator<Value> iter = sub.members();
+          final Iterator<Value> iter = sub.iterator(0);
           for(int i = 0; i < k; i++) {
             final long res = ((Int) iter.next()).itr();
             if(res != pos + i) {
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/query/value/array/VariousArrayTest.java basex-8.2.3/basex-core/src/test/java/org/basex/query/value/array/VariousArrayTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/query/value/array/VariousArrayTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/query/value/array/VariousArrayTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -148,7 +148,7 @@
         final Array seq2 = seq.remove(i);
         assertEquals(k - 1, seq2.arraySize());
 
-        final Iterator<Value> iter = seq2.members();
+        final Iterator<Value> iter = seq2.iterator(0);
         for(int j = 0; j < k - 1; j++) {
           assertTrue(iter.hasNext());
           assertEquals(j < i ? j : j + 1, ((Int) iter.next()).itr());
@@ -166,13 +166,13 @@
   public void iteratorTest() {
     final int n = 1_000;
     Array seq = Array.empty();
-    assertFalse(seq.members().hasNext());
+    assertFalse(seq.iterator(0).hasNext());
 
     for(int i = 0; i < n; i++) {
       final Int val = Int.get(i);
       seq = seq.cons(val).snoc(val);
       final int k = 2 * (i + 1);
-      final Iterator<Value> iter = seq.members();
+      final Iterator<Value> iter = seq.iterator(0);
       for(int j = 0; j < k; j++) {
         assertTrue(iter.hasNext());
         final Value next = iter.next();
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/SandboxTest.java basex-8.2.3/basex-core/src/test/java/org/basex/SandboxTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/SandboxTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/SandboxTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,19 +1,6 @@
 package org.basex;
 
-import static org.basex.core.Text.*;
-import static org.junit.Assert.*;
-
-import java.io.*;
-import java.util.concurrent.*;
-
-import org.basex.api.client.*;
 import org.basex.core.*;
-import org.basex.core.users.*;
-import org.basex.io.*;
-import org.basex.io.out.*;
-import org.basex.util.*;
-import org.basex.util.list.*;
-import org.basex.util.options.*;
 import org.junit.*;
 
 /**
@@ -22,166 +9,20 @@
  * @author BaseX Team 2005-15, BSD License
  * @author Christian Gruen
  */
-public abstract class SandboxTest {
-  /** Database port. */
-  protected static final int DB_PORT = 9996;
-  /** Event port. */
-  protected static final int EVENT_PORT = 9997;
-
-  /** Default output stream. */
-  public static final PrintStream OUT = System.out;
-  /** Default error stream. */
-  public static final PrintStream ERR = System.err;
-  /** Null output stream. */
-  public static final PrintStream NULL = new PrintStream(new NullOutput());
-  /** Test name. */
-  protected static final String NAME = Util.className(SandboxTest.class);
-  /** Database context. */
-  protected static Context context;
-
+public abstract class SandboxTest extends Sandbox {
   /**
    * Creates the sandbox.
    */
   @BeforeClass
-  public static void initSandbox() {
-    final IOFile sb = sandbox();
-    sb.delete();
-    assertTrue("Sandbox could not be created.", sb.md());
-    context = newContext();
+  public static void initTests() {
+    initSandbox();
   }
 
   /**
    * Removes test databases and closes the database context.
    */
   @AfterClass
-  public static void closeContext() {
-    context.close();
-    assertTrue("Sandbox could not be deleted.", sandbox().delete());
-  }
-
-  /**
-   * Creates a new specified context.
-   * @return context
-   */
-  public static Context newContext() {
-    final IOFile sb = sandbox();
-    Options.setSystem(StaticOptions.DBPATH.name(), sb.path() + "/data");
-    Options.setSystem(StaticOptions.WEBPATH.name(), sb.path() + "/webapp");
-    Options.setSystem(StaticOptions.RESTXQPATH.name(), sb.path() + "/webapp");
-    Options.setSystem(StaticOptions.REPOPATH.name(), sb.path() + "/repo");
-    try {
-      return new Context();
-    } finally {
-      Options.setSystem(StaticOptions.DBPATH.name(), "");
-      Options.setSystem(StaticOptions.WEBPATH.name(), "");
-      Options.setSystem(StaticOptions.RESTXQPATH.name(), "");
-      Options.setSystem(StaticOptions.REPOPATH.name(), "");
-    }
-  }
-
-  /**
-   * Creates a new, sandboxed server instance.
-   * @param args additional arguments
-   * @return server instance
-   * @throws IOException I/O exception
-   */
-  public static BaseXServer createServer(final String... args) throws IOException {
-    try {
-      System.setOut(NULL);
-      final StringList sl = new StringList("-z", "-p" + DB_PORT, "-e" + EVENT_PORT, "-q");
-      for(final String arg : args) sl.add(arg);
-      final BaseXServer server = new BaseXServer(sl.finish());
-      server.context.soptions.set(StaticOptions.DBPATH, sandbox().path());
-      return server;
-    } finally {
-      System.setOut(OUT);
-    }
-  }
-
-  /**
-   * Stops a server instance.
-   * @param server server
-   * @throws IOException I/O exception
-   */
-  public static void stopServer(final BaseXServer server) throws IOException {
-    try {
-      System.setOut(NULL);
-      if(server != null) server.stop();
-    } finally {
-      System.setOut(OUT);
-    }
-  }
-
-  /**
-   * Creates a client instance.
-   * @param login optional login data
-   * @return client instance
-   * @throws IOException I/O exception
-   */
-  public static ClientSession createClient(final String... login) throws IOException {
-    final String user = login.length > 0 ? login[0] : UserText.ADMIN;
-    final String pass = login.length > 1 ? login[1] : UserText.ADMIN;
-    return new ClientSession(S_LOCALHOST, DB_PORT, user, pass);
-  }
-
-  /**
-   * Returns the sandbox database path.
-   * @return database path
-   */
-  public static IOFile sandbox() {
-    return new IOFile(Prop.TMP, NAME);
-  }
-
-  /**
-   * Normalizes newlines in a query result.
-   * @param result input string
-   * @return normalized string
-   */
-  public static String normNL(final Object result) {
-    return result.toString().replaceAll("(\r?\n|\r) *", "\n");
-  }
-
-  /** Client. */
-  public static final class Client extends Thread {
-    /** Start signal. */
-    private final CountDownLatch startSignal;
-    /** Stop signal. */
-    private final CountDownLatch stopSignal;
-    /** Client session. */
-    private final ClientSession session;
-    /** Command string. */
-    private final Command cmd;
-    /** Fail flag. */
-    public String error;
-
-    /**
-     * Client constructor.
-     * @param c command string to execute
-     * @param start start signal
-     * @param stop stop signal
-     * @throws IOException I/O exception while establishing the session
-     */
-    public Client(final Command c, final CountDownLatch start, final CountDownLatch stop)
-        throws IOException {
-
-      session = createClient();
-      cmd = c;
-      startSignal = start;
-      stopSignal = stop;
-      start();
-    }
-
-    @Override
-    public void run() {
-      try {
-        if(startSignal != null) startSignal.await();
-        session.execute(cmd);
-        session.close();
-      } catch(final Throwable ex) {
-        error = "\n" + cmd + '\n' + ex;
-      } finally {
-        if(stopSignal != null) stopSignal.countDown();
-      }
-    }
+  public static void finishTests() {
+    finishSandbox();
   }
 }
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/server/AdminStressTest.java basex-8.2.3/basex-core/src/test/java/org/basex/server/AdminStressTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/server/AdminStressTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/server/AdminStressTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -6,9 +6,7 @@
 import java.util.concurrent.*;
 
 import org.basex.*;
-import org.basex.api.client.*;
 import org.basex.core.cmd.*;
-import org.basex.util.*;
 import org.junit.*;
 import org.junit.Test;
 
@@ -19,7 +17,7 @@
  * @author Dimitar Popov
  */
 public final class AdminStressTest extends SandboxTest {
-  /** Number of clients/events. */
+  /** Number of clients. */
   private static final int NUM = 100;
   /** Server reference. */
   private static BaseXServer server;
@@ -43,35 +41,7 @@
   }
 
   /**
-   * Start simultaneously clients which create events and clients which list all events.
-   * @throws Exception exception
-   */
-  @Test
-  public void createAndListEvents() throws Exception {
-    final CountDownLatch start = new CountDownLatch(1);
-    final CountDownLatch stop = new CountDownLatch(NUM);
-
-    final Client[] c1 = new Client[NUM];
-    final Client[] c2 = new Client[NUM];
-    for(int i = 0; i < NUM; ++i) {
-      c1[i] = new Client(new CreateEvent(NAME + i), start, stop);
-      c2[i] = new Client(new ShowEvents(), start, stop);
-    }
-    start.countDown(); // start all clients
-    stop.await();
-
-    Performance.sleep(200);
-    try(final ClientSession cs = createClient()) {
-      for(int i = 0; i < NUM; ++i) cs.execute("drop event " + NAME + i);
-    }
-
-    for(final Client c : c1) if(c.error != null) fail(c.error);
-    for(final Client c : c2) if(c.error != null) fail(c.error);
-  }
-
-  /**
-   * Start simultaneously clients which create events and clients which list all
-   * events.
+   * Test simultaneous client sessions.
    * @throws Exception exception
    */
   @Test
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/server/EventTest.java basex-8.2.3/basex-core/src/test/java/org/basex/server/EventTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/server/EventTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/server/EventTest.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,285 +0,0 @@
-package org.basex.server;
-
-import static org.basex.query.func.Function.*;
-import static org.junit.Assert.*;
-import java.io.*;
-import java.util.*;
-import java.util.concurrent.*;
-
-import org.basex.*;
-import org.basex.api.client.*;
-import org.basex.core.*;
-import org.basex.util.*;
-import org.junit.*;
-
-/**
- * This class tests the event API.
- *
- * @author BaseX Team 2005-15, BSD License
- * @author Roman Raedle
- * @author Andreas Weiler
- */
-public final class EventTest extends SandboxTest {
-  /** Return value of function db:event. */
-  private static final String RETURN = "ABCDEFGHIJKLMNOP";
-  /** Event count. */
-  private static final int EVENT_COUNT = 10;
-  /** Client count. */
-  private static final int CLIENTS = 10;
-
-  /** Server reference. */
-  private static BaseXServer server;
-  /** Admin session. */
-  private ClientSession session;
-  /** Control client sessions. */
-  private final ClientSession[] sessions = new ClientSession[CLIENTS];
-
-  /**
-   * Starts the server.
-   * @throws IOException I/O exception
-   */
-  @BeforeClass
-  public static void start() throws IOException {
-    server = createServer();
-  }
-
-  /**
-   * Starts the sessions.
-   * @throws IOException I/O exception
-   */
-  @Before
-  public void startSessions() throws IOException {
-    session = createClient();
-    // drop event if not done yet
-    try {
-      session.execute("drop event " + NAME);
-    } catch(final IOException ignored) { }
-
-    final int sl = sessions.length;
-    for(int i = 0; i < sl; i++) sessions[i] = createClient();
-  }
-
-  /**
-   * Stops the sessions.
-   * @throws IOException I/O exception
-   */
-  @After
-  public void stopSessions() throws IOException {
-    for(final ClientSession cs : sessions) cs.close();
-    session.close();
-  }
-
-  /**
-   * Stops the server.
-   * @throws IOException I/O exception
-   */
-  @AfterClass
-  public static void stop() throws IOException {
-    stopServer(server);
-  }
-
-  /**
-   * Creates and drops events.
-   * @throws IOException I/O exception
-   */
-  @Test
-  public void createDrop() throws IOException {
-    final String[] events = new String[EVENT_COUNT];
-    for(int i = 0; i < EVENT_COUNT; i++) events[i] = NAME + i;
-
-    try {
-      // create event
-      for(final String e : events) session.execute("create event " + e);
-
-      // query must return all events
-      final HashSet<String> names = new HashSet<>();
-      final String result = session.execute("show events");
-      for(final String line : result.split("\\r?\\n|\\r"))
-        if(line.startsWith("- ")) names.add(line.substring(2));
-
-      for(final String ev : events)
-        assertTrue("Event '" + ev + "' not created!", names.contains(ev));
-    } finally {
-      // drop events as last action, preventing leftovers
-      for(final String ev : events) session.execute("drop event " + ev);
-    }
-  }
-
-  /**
-   * Watches and unwatches events.
-   * @throws IOException I/O exception
-   */
-  @Test
-  public void watchUnwatch() throws IOException {
-    // create event
-    session.execute("create event " + NAME);
-    // create event
-    try {
-      session.execute("create event " + NAME);
-      fail("This was supposed to fail.");
-    } catch(final IOException ex) { /* expected. */ }
-
-    // watch an event
-    for(final ClientSession cs : sessions) {
-      cs.watch(NAME, new EventNotifier() {
-        @Override
-        public void notify(final String data) { }
-      });
-    }
-    // watch an unknown event
-    try {
-      for(final ClientSession cs : sessions) {
-        cs.watch(NAME + 1, new EventNotifier() {
-          @Override
-          public void notify(final String data) { }
-        });
-        fail("This was supposed to fail.");
-      }
-    } catch(final IOException ex) { /* expected. */ }
-
-    // unwatch event
-    for(final ClientSession cs : sessions) {
-      cs.unwatch(NAME);
-    }
-    // unwatch unknown event
-    try {
-      for(final ClientSession cs : sessions) {
-        cs.unwatch(NAME + 1);
-        fail("This was supposed to fail.");
-      }
-    } catch(final IOException ex) { /* expected. */ }
-
-    // drop the event
-    session.execute("drop event " + NAME);
-    // drop event
-    try {
-      session.execute("drop event " + NAME);
-      fail("This was supposed to fail.");
-    } catch(final IOException ex) { /* expected. */ }
-  }
-
-  /**
-   * Runs event test with specified second query and without.
-   * @throws IOException I/O exception
-   * @throws InterruptedException waiting interrupted
-   */
-  @Test
-  public void event() throws IOException, InterruptedException {
-    // create the event
-    // ignore the error that the event may already exist
-    try {
-      session.execute("create event " + NAME);
-    } catch(final BaseXException ignore) { }
-
-    final CountDownLatch doneSignal = new CountDownLatch(sessions.length);
-    // watch event
-    for(final ClientSession cs : sessions) {
-      cs.watch(NAME, new EventNotifier() {
-        @Override
-        public void notify(final String data) {
-          doneSignal.countDown();
-          assertEquals(RETURN, data);
-        }
-      });
-    }
-    // fire an event
-    session.query(_DB_EVENT.args(NAME, RETURN)).execute();
-
-    // wait for half a second that the event is fired
-    assertTrue(doneSignal.await(500, TimeUnit.MILLISECONDS));
-
-    // all clients unwatch the events
-    for(final ClientSession cs : sessions) cs.unwatch(NAME);
-
-    // drop event
-    session.execute("drop event " + NAME);
-  }
-
-  /**
-   * Concurrent events.
-   * @throws Exception exception
-   */
-  @Test
-  public void concurrent() throws Exception {
-    // create events
-    // ignore the error that the event may already exist
-    try {
-      session.execute("create event " + NAME);
-      session.execute("create event " + NAME + 1);
-    } catch(final BaseXException ignore) { }
-
-    final CountDownLatch doneSignal = new CountDownLatch(CLIENTS * sessions.length);
-    // watch events on all clients
-    for(final ClientSession cs : sessions) {
-      cs.watch(NAME, new EventNotifier() {
-        @Override
-        public void notify(final String data) {
-          doneSignal.countDown();
-          assertEquals(RETURN, data);
-        }
-      });
-      cs.watch(NAME + 1, new EventNotifier() {
-        @Override
-        public void notify(final String data) {
-          doneSignal.countDown();
-          assertEquals(RETURN, data);
-        }
-      });
-    }
-
-    // fire events
-    final Client[] clients = new Client[CLIENTS];
-    for(int c = 0; c < CLIENTS; c++) {
-      clients[c] = new Client(c % 2 == 0, RETURN);
-    }
-    for(final Client c : clients) c.start();
-    for(final Client c : clients) c.join();
-
-    // wait for half a second that the event is fired
-    assertTrue(doneSignal.await(500, TimeUnit.MILLISECONDS));
-
-    // unwatch events
-    for(final ClientSession cs : sessions) {
-      cs.unwatch(NAME);
-      cs.unwatch(NAME + 1);
-    }
-
-    // drop event
-    session.execute("drop event " + NAME);
-    session.execute("drop event " + NAME + 1);
-  }
-
-  /** Single client. */
-  static final class Client extends Thread {
-    /** Client session. */
-    private final ClientSession cs;
-    /** First event. */
-    private final boolean first;
-    /** Event value. */
-    private final String value;
-
-    /**
-     * Default constructor.
-     * @param f first flag
-     * @param v value
-     * @throws IOException I/O exception
-     */
-    Client(final boolean f, final String v) throws IOException {
-      cs = createClient();
-      first = f;
-      value = v;
-    }
-
-    @Override
-    public void run() {
-      try {
-        String name = NAME;
-        if(!first) name += 1;
-        cs.query(_DB_EVENT.args(name, value)).execute();
-        cs.close();
-      } catch(final Exception ex) {
-        Util.stack(ex);
-      }
-    }
-  }
-}
diff -Nru basex-8.1.1/basex-core/src/test/java/org/basex/server/SessionTest.java basex-8.2.3/basex-core/src/test/java/org/basex/server/SessionTest.java
--- basex-8.1.1/basex-core/src/test/java/org/basex/server/SessionTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/java/org/basex/server/SessionTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -14,6 +14,7 @@
 import org.basex.io.in.*;
 import org.basex.io.out.*;
 import org.basex.io.serial.*;
+import org.basex.query.util.list.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.node.*;
 import org.basex.query.value.seq.*;
@@ -442,7 +443,7 @@
     }
 
     try(Query query = session.query("declare variable $a external; $a")) {
-      query.bind("a", Seq.get(new Item[] { Int.get(1), Str.get("X") }));
+      query.bind("a", new ItemList().add(Int.get(1)).add(Str.get("X")).value());
       assertEqual("1", query.next());
       assertEqual("X", query.next());
     }
diff -Nru basex-8.1.1/basex-core/src/test/resources/hello.xqm basex-8.2.3/basex-core/src/test/resources/hello.xqm
--- basex-8.1.1/basex-core/src/test/resources/hello.xqm	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-core/src/test/resources/hello.xqm	2015-07-14 10:54:40.000000000 +0000
@@ -28,6 +28,6 @@
 };
 
 (:~ Private function returning a simple string. :)
-declare %private function hello:internal() as xs:string {
+declare %private %Q{ns}ignored function hello:internal() as xs:string {
   "hello world"
 };
diff -Nru basex-8.1.1/basex-examples/pom.xml basex-8.2.3/basex-examples/pom.xml
--- basex-8.1.1/basex-examples/pom.xml	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-examples/pom.xml	2015-07-14 10:54:40.000000000 +0000
@@ -8,7 +8,7 @@
   <parent>
     <groupId>org.basex</groupId>
     <artifactId>basex-parent</artifactId>
-    <version>8.1.1</version>
+    <version>8.2.3</version>
     <relativePath>..</relativePath>
   </parent>
 
diff -Nru basex-8.1.1/basex-examples/.settings/checkstyle.xml basex-8.2.3/basex-examples/.settings/checkstyle.xml
--- basex-8.1.1/basex-examples/.settings/checkstyle.xml	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-examples/.settings/checkstyle.xml	2015-07-14 10:54:40.000000000 +0000
@@ -26,7 +26,7 @@
     <module name="IllegalImport"/>
     <module name="RedundantImport"/>
     <module name="LineLength">
-      <property name="ignorePattern" value="^import"/>
+      <property name="ignorePattern" value="^(import| \*)"/>
       <property name="max" value="100"/>
       <property name="tabWidth" value="2"/>
     </module>
@@ -50,7 +50,6 @@
     </module>
     <module name="ModifierOrder"/>
     <module name="RedundantModifier"/>
-    <module name="AvoidNestedBlocks"/>
     <module name="EqualsHashCode">
       <property name="severity" value="ignore"/>
       <metadata name="net.sf.eclipsecs.core.lastEnabledSeverity" value="inherit"/>
diff -Nru basex-8.1.1/basex-examples/src/main/java/org/basex/examples/api/BaseXClient.java basex-8.2.3/basex-examples/src/main/java/org/basex/examples/api/BaseXClient.java
--- basex-8.1.1/basex-examples/src/main/java/org/basex/examples/api/BaseXClient.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-examples/src/main/java/org/basex/examples/api/BaseXClient.java	2015-07-14 10:54:40.000000000 +0000
@@ -17,9 +17,6 @@
 public final class BaseXClient {
   /** UTF-8 charset. */
   private static final Charset UTF8 = Charset.forName("UTF-8");
-  /** Event notifications. */
-  private final Map<String, EventNotifier> notifiers =
-      Collections.synchronizedMap(new HashMap<String, EventNotifier>());
   /** Output stream. */
   private final OutputStream out;
   /** Input stream (buffered). */
@@ -29,10 +26,6 @@
   private final Socket socket;
   /** Command info. */
   private String info;
-  /** Socket event reference. */
-  private Socket esocket;
-  /** Socket event host. */
-  private final String ehost;
 
   /**
    * Constructor.
@@ -49,7 +42,6 @@
     socket.connect(new InetSocketAddress(host, port), 5000);
     in = new BufferedInputStream(socket.getInputStream());
     out = socket.getOutputStream();
-    ehost = host;
 
     // receive server response
     final String[] response = receive().split(":");
@@ -148,46 +140,6 @@
   }
 
   /**
-   * Watches an event.
-   * @param name event name
-   * @param notifier event notification
-   * @throws IOException I/O exception
-   */
-  public void watch(final String name, final EventNotifier notifier) throws IOException {
-    out.write(10);
-    if(esocket == null) {
-      final int eport = Integer.parseInt(receive());
-      // initialize event socket
-      esocket = new Socket();
-      esocket.connect(new InetSocketAddress(ehost, eport), 5000);
-      final OutputStream os = esocket.getOutputStream();
-      receive(in, os);
-      os.write(0);
-      os.flush();
-      final InputStream is = esocket.getInputStream();
-      is.read();
-      listen(is);
-    }
-    send(name);
-    info = receive();
-    if(!ok()) throw new IOException(info);
-    notifiers.put(name, notifier);
-  }
-
-  /**
-   * Unwatches an event.
-   * @param name event name
-   * @throws IOException I/O exception
-   */
-  public void unwatch(final String name) throws IOException {
-    out.write(11);
-    send(name);
-    info = receive();
-    if(!ok()) throw new IOException(info);
-    notifiers.remove(name);
-  }
-
-  /**
    * Returns command information.
    * @return string info
    */
@@ -202,7 +154,6 @@
   public void close() throws IOException {
     send("exit");
     out.flush();
-    if(esocket != null) esocket.close();
     socket.close();
   }
 
@@ -264,32 +215,6 @@
   }
 
   /**
-   * Starts the listener thread.
-   * @param input input stream
-   */
-  private void listen(final InputStream input) {
-    final BufferedInputStream bis = new BufferedInputStream(input);
-    new Thread() {
-      @Override
-      public void run() {
-        try {
-          while(true) {
-            ByteArrayOutputStream baos = new ByteArrayOutputStream();
-            receive(bis, baos);
-            final String name = new String(baos.toByteArray(), UTF8);
-            baos = new ByteArrayOutputStream();
-            receive(bis, baos);
-            final String data = new String(baos.toByteArray(), UTF8);
-            notifiers.get(name).notify(data);
-          }
-        } catch(final IOException ex) {
-          // loop will be quit if no data can be received anymore
-        }
-      }
-    }.start();
-  }
-
-  /**
    * Sends an input stream to the server.
    * @param input xml input
    * @throws IOException I/O exception
@@ -475,15 +400,4 @@
       return s;
     }
   }
-
-  /**
-   * Interface for event notifications.
-   */
-  public interface EventNotifier {
-    /**
-     * Invoked when a database event was fired.
-     * @param value event string
-     */
-    void notify(final String value);
-  }
 }
\ No newline at end of file
diff -Nru basex-8.1.1/basex-examples/src/main/java/org/basex/examples/api/EventExample.java basex-8.2.3/basex-examples/src/main/java/org/basex/examples/api/EventExample.java
--- basex-8.1.1/basex-examples/src/main/java/org/basex/examples/api/EventExample.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-examples/src/main/java/org/basex/examples/api/EventExample.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,49 +0,0 @@
-package org.basex.examples.api;
-
-import java.io.*;
-
-/**
- * This example demonstrates how to trigger and receive database events.
- *
- * This example requires a running database server instance.
- * Documentation: http://docs.basex.org/wiki/Clients
- *
- * @author BaseX Team 2005-15, BSD License
- */
-public final class EventExample {
-  /**
-   * Main method.
-   * @param args command-line arguments
-   */
-  public static void main(final String[] args) {
-    try {
-      final BaseXClient session1 = new BaseXClient("localhost", 1984, "admin", "admin");
-      final BaseXClient session2 = new BaseXClient("localhost", 1984, "admin", "admin");
-
-      session1.execute("create event messenger");
-      session2.watch("messenger", new Notifier());
-      session2.query("for $i in 1 to 1000000 where $i = 0 return $i").execute();
-      session1.query("db:event('messenger', 'Hello World!')").execute();
-      session2.unwatch("messenger");
-      session1.execute("drop event messenger");
-      session1.close();
-      session2.close();
-
-    } catch(final IOException e) {
-      e.printStackTrace();
-    }
-  }
-
-  /**
-   * Implementation of the event notifier interface.
-   */
-  private static class Notifier implements BaseXClient.EventNotifier {
-    /** Constructor. */
-    Notifier() { }
-
-    @Override
-    public void notify(final String value) {
-      System.out.println("Message received: " + value);
-    }
-  }
-}
diff -Nru basex-8.1.1/basex-examples/src/main/java/org/basex/examples/local/BindContext.java basex-8.2.3/basex-examples/src/main/java/org/basex/examples/local/BindContext.java
--- basex-8.1.1/basex-examples/src/main/java/org/basex/examples/local/BindContext.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-examples/src/main/java/org/basex/examples/local/BindContext.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,8 +1,8 @@
 package org.basex.examples.local;
 
 import org.basex.core.*;
-import org.basex.data.*;
 import org.basex.query.*;
+import org.basex.query.value.*;
 
 /**
  * This example demonstrates how items can be bound as context item of
@@ -39,7 +39,7 @@
       qp.context(item);
 
       // Execute the query
-      Result result = qp.execute();
+      Value result = qp.value();
 
       // Print result as string
       System.out.println("\n* Result:");
diff -Nru basex-8.1.1/basex-examples/src/main/java/org/basex/examples/local/BindVariables.java basex-8.2.3/basex-examples/src/main/java/org/basex/examples/local/BindVariables.java
--- basex-8.1.1/basex-examples/src/main/java/org/basex/examples/local/BindVariables.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-examples/src/main/java/org/basex/examples/local/BindVariables.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,8 +1,8 @@
 package org.basex.examples.local;
 
 import org.basex.core.*;
-import org.basex.data.*;
 import org.basex.query.*;
+import org.basex.query.value.*;
 
 /**
  * This example demonstrates how items can be bound to variables with
@@ -44,7 +44,7 @@
       proc.bind("var2", number, "xs:integer");
 
       // Execute the query
-      Result result = proc.execute();
+      Value result = proc.value();
 
       System.out.println("\n* Result:");
 
diff -Nru basex-8.1.1/basex-examples/src/main/java/org/basex/examples/local/RunQueries.java basex-8.2.3/basex-examples/src/main/java/org/basex/examples/local/RunQueries.java
--- basex-8.1.1/basex-examples/src/main/java/org/basex/examples/local/RunQueries.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-examples/src/main/java/org/basex/examples/local/RunQueries.java	2015-07-14 10:54:40.000000000 +0000
@@ -4,10 +4,10 @@
 
 import org.basex.core.*;
 import org.basex.core.cmd.*;
-import org.basex.data.*;
 import org.basex.io.serial.*;
 import org.basex.query.*;
 import org.basex.query.iter.*;
+import org.basex.query.value.*;
 import org.basex.query.value.item.*;
 
 /**
@@ -82,7 +82,7 @@
     // Create a query processor
     try(QueryProcessor proc = new QueryProcessor(query, context)) {
       // Execute the query
-      Result result = proc.execute();
+      Value result = proc.value();
 
       // Print result as string.
       System.out.println(result);
diff -Nru basex-8.1.1/basex-examples/src/main/java/org/basex/examples/module/FruitsExample.java basex-8.2.3/basex-examples/src/main/java/org/basex/examples/module/FruitsExample.java
--- basex-8.1.1/basex-examples/src/main/java/org/basex/examples/module/FruitsExample.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-examples/src/main/java/org/basex/examples/module/FruitsExample.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,8 +1,8 @@
 package org.basex.examples.module;
 
 import org.basex.core.*;
-import org.basex.data.*;
 import org.basex.query.*;
+import org.basex.query.value.*;
 
 /**
  * This example demonstrates how Java classes can be imported as XQuery modules.
@@ -42,7 +42,7 @@
     // Create a query processor
     try(QueryProcessor processor = new QueryProcessor(query, context)) {
       // Execute the query
-      Result result = processor.execute();
+      Value result = processor.value();
 
       System.out.println("\n* Result:");
 
diff -Nru basex-8.1.1/basex-examples/src/main/java/org/basex/examples/module/ModuleDemo.java basex-8.2.3/basex-examples/src/main/java/org/basex/examples/module/ModuleDemo.java
--- basex-8.1.1/basex-examples/src/main/java/org/basex/examples/module/ModuleDemo.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-examples/src/main/java/org/basex/examples/module/ModuleDemo.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,7 +1,6 @@
 package org.basex.examples.module;
 
 import org.basex.query.*;
-import org.basex.query.iter.*;
 import org.basex.query.value.*;
 import org.basex.query.value.item.*;
 import org.basex.query.value.node.*;
@@ -80,8 +79,8 @@
     ValueBuilder vb = new ValueBuilder();
     for(final Item item : value) {
       if(item instanceof DBNode) {
-        DBNode node = (DBNode) item;
-        int id = node.data.id(node.pre);
+        final DBNode node = (DBNode) item;
+        int id = node.data().id(node.pre());
         vb.add(Int.get(id));
       }
     }
diff -Nru basex-8.1.1/basex-examples/src/main/java/org/basex/examples/server/ServerEventsGUI.java basex-8.2.3/basex-examples/src/main/java/org/basex/examples/server/ServerEventsGUI.java
--- basex-8.1.1/basex-examples/src/main/java/org/basex/examples/server/ServerEventsGUI.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-examples/src/main/java/org/basex/examples/server/ServerEventsGUI.java	1970-01-01 00:00:00.000000000 +0000
@@ -1,163 +0,0 @@
-package org.basex.examples.server;
-
-import static org.basex.core.users.UserText.*;
-import java.awt.*;
-import java.awt.event.*;
-import java.io.*;
-
-import javax.swing.*;
-import javax.swing.border.*;
-
-import org.basex.*;
-import org.basex.api.client.*;
-import org.basex.server.*;
-import org.basex.util.*;
-
-/**
- * This class tests the event mechanism with a gui.
- *
- * @author BaseX Team 2005-15, BSD License
- */
-public final class ServerEventsGUI extends JFrame {
-  /** Name of test database and user. */
-  static final String NAME = Util.className(ServerEventsGUI.class);
-  /** Number of clients. */
-  static final int CLIENTS = 2;
-  /** Color. */
-  static final String RED = "RED";
-  /** Color. */
-  static final String BLUE = "BLUE";
-  /** Color. */
-  static final String YELLOW = "YELLOW";
-
-  /** Database server. */
-  private static BaseXServer server;
-  /** Number of open windows. */
-  private static int open = CLIENTS;
-
-  /** Client session. */
-  ClientSession session;
-  /** Main panel. */
-  JPanel main;
-
-  /**
-   * Main method, launching the test gui.
-   * @param args ignored
-   * @throws Exception exception
-   */
-  public static void main(final String[] args) throws Exception {
-    server = new BaseXServer("-z");
-
-    // initialization
-    try(ClientSession cs = new ClientSession(server.context, ADMIN, ADMIN)) {
-      cs.execute("create event " + NAME);
-      cs.execute("create db " + NAME + " <Application><Background/></Application>");
-    }
-
-    for(int i = 0; i < CLIENTS; i++) new ServerEventsGUI(i);
-  }
-
-  /**
-   * Default Constructor.
-   * @param count window counter
-   * @throws IOException I/O exception
-   */
-  private ServerEventsGUI(final int count) throws IOException {
-    super("Window " + (count + 1));
-
-    JPanel buttons = new JPanel();
-    buttons.setLayout(new FlowLayout());
-    buttons.setOpaque(false);
-
-    final JTextArea area = new JTextArea();
-    area.setPreferredSize(new Dimension(280, 90));
-    area.setEditable(false);
-    area.setBorder(new CompoundBorder(new EtchedBorder(),
-        new EmptyBorder(10, 10, 10, 10)));
-
-    // create notifier instance
-    final EventNotifier en = new EventNotifier() {
-      @Override
-      public void notify(final String value) {
-        // use event feedback to repaint background
-        Color c = Color.WHITE;
-        String tmp = value.replaceAll("\"", "");
-        if(tmp.equals(RED)) {
-          c = Color.RED;
-        } else if(tmp.equals(BLUE)) {
-          c = Color.BLUE;
-        } else if(tmp.equals(YELLOW)) {
-          c = Color.YELLOW;
-        }
-        main.setBackground(c);
-
-        // display updated XML fragment
-        try(final ClientQuery cq = session.query("/")) {
-          area.setText(cq.execute());
-        } catch(IOException ex) {
-          ex.printStackTrace();
-        }
-      }
-    };
-
-    // create session, open database and register event watcher
-    session = new ClientSession(server.context, ADMIN, ADMIN);
-    session.execute("open " + NAME);
-    session.watch(NAME, en);
-
-    // create notification buttons
-    for(final String color : new String[] { RED, BLUE, YELLOW }) {
-      final JButton b = new JButton(color);
-      // create action event
-      b.addActionListener(new ActionListener() {
-        @Override
-        public void actionPerformed(final ActionEvent e) {
-          try {
-            // send update query and event
-            String query =
-              "let $color := '" + color + "' return " +
-              "(replace value of node /Application/Background with $color," +
-              " db:event('" + NAME + "', $color))";
-            try(ClientQuery cq = session.query(query)) {
-              cq.execute();
-            }
-          } catch(IOException ex) {
-            ex.printStackTrace();
-          }
-          en.notify(b.getText());
-        }
-      });
-      buttons.add(b);
-    }
-
-    main = new JPanel();
-    main.setLayout(new BorderLayout());
-    main.setBackground(Color.WHITE);
-    main.add(area, BorderLayout.CENTER);
-    main.add(buttons, BorderLayout.SOUTH);
-
-    add(main);
-    pack();
-    setLocation(300 * count, 0);
-    setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
-    setVisible(true);
-  }
-
-  @Override
-  public void dispose() {
-    try {
-      session.close();
-      if(--open == 0) {
-        // no sessions left: drop event and database and stop server
-        try(ClientSession css = new ClientSession(server.context, ADMIN, ADMIN)) {
-          css.execute("drop event " + NAME);
-          css.execute("drop db " + NAME);
-        }
-        server.stop();
-      }
-      super.dispose();
-    } catch(Exception ex) {
-      ex.printStackTrace();
-    }
-  }
-}
diff -Nru basex-8.1.1/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Main.java basex-8.2.3/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Main.java
--- basex-8.1.1/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Main.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Main.java	2015-07-14 10:54:40.000000000 +0000
@@ -5,10 +5,9 @@
 import net.xqj.basex.*;
 
 /**
- * XQJ Examples, derived from the XQJ Tutorial
- * <a href="http://www.xquery.com/tutorials/xqj_tutorial">
- * http://www.xquery.com/tutorials/xqj_tutorial</a>
- * from Marc van Cappellen.
+ * XQJ Examples, derived from an
+ * <a href="https://www.progress.com/products/data-integration-suite/data-integration-suite-developer-center/data-integration-suite-tutorials/learning-xquery/introduction-to-the-xquery-api-for-java-xqj-">
+ * XQJ online tutorial</a>.
  *
  * @author BaseX Team 2005-15, BSD License
  */
diff -Nru basex-8.1.1/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part10.java basex-8.2.3/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part10.java
--- basex-8.1.1/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part10.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part10.java	2015-07-14 10:54:40.000000000 +0000
@@ -12,10 +12,9 @@
 import org.xml.sax.helpers.*;
 
 /**
- * XQJ Example, derived from the XQJ Tutorial
- * <a href="http://www.xquery.com/tutorials/xqj_tutorial">
- * http://www.xquery.com/tutorials/xqj_tutorial</a>
- * from Marc van Cappellen.
+ * XQJ Examples, derived from an
+ * <a href="https://www.progress.com/products/data-integration-suite/data-integration-suite-developer-center/data-integration-suite-tutorials/learning-xquery/introduction-to-the-xquery-api-for-java-xqj-">
+ * XQJ online tutorial</a>.
  *
  * Part 10: XML Pipelines.
  *
diff -Nru basex-8.1.1/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part11.java basex-8.2.3/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part11.java
--- basex-8.1.1/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part11.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part11.java	2015-07-14 10:54:40.000000000 +0000
@@ -7,10 +7,9 @@
 import javax.xml.xquery.*;
 
 /**
- * XQJ Example, derived from the XQJ Tutorial
- * <a href="http://www.xquery.com/tutorials/xqj_tutorial">
- * http://www.xquery.com/tutorials/xqj_tutorial</a>
- * from Marc van Cappellen.
+ * XQJ Examples, derived from an
+ * <a href="https://www.progress.com/products/data-integration-suite/data-integration-suite-developer-center/data-integration-suite-tutorials/learning-xquery/introduction-to-the-xquery-api-for-java-xqj-">
+ * XQJ online tutorial</a>.
  *
  * Part 11: Processing Large Inputs.
  *
diff -Nru basex-8.1.1/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part1.java basex-8.2.3/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part1.java
--- basex-8.1.1/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part1.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part1.java	2015-07-14 10:54:40.000000000 +0000
@@ -5,10 +5,9 @@
 import net.xqj.basex.*;
 
 /**
- * XQJ Example, derived from the XQJ Tutorial
- * <a href="http://www.xquery.com/tutorials/xqj_tutorial">
- * http://www.xquery.com/tutorials/xqj_tutorial</a>
- * from Marc van Cappellen.
+ * XQJ Examples, derived from an
+ * <a href="https://www.progress.com/products/data-integration-suite/data-integration-suite-developer-center/data-integration-suite-tutorials/learning-xquery/introduction-to-the-xquery-api-for-java-xqj-">
+ * XQJ online tutorial</a>.
  *
  * Part 1: An XQJ Introduction.
  *
diff -Nru basex-8.1.1/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part2.java basex-8.2.3/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part2.java
--- basex-8.1.1/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part2.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part2.java	2015-07-14 10:54:40.000000000 +0000
@@ -5,10 +5,9 @@
 import javax.xml.xquery.*;
 
 /**
- * XQJ Example, derived from the XQJ Tutorial
- * <a href="http://www.xquery.com/tutorials/xqj_tutorial">
- * http://www.xquery.com/tutorials/xqj_tutorial</a>
- * from Marc van Cappellen.
+ * XQJ Examples, derived from an
+ * <a href="https://www.progress.com/products/data-integration-suite/data-integration-suite-developer-center/data-integration-suite-tutorials/learning-xquery/introduction-to-the-xquery-api-for-java-xqj-">
+ * XQJ online tutorial</a>.
  *
  * Part 2: Configuring XQJ Connections.
  *
diff -Nru basex-8.1.1/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part3.java basex-8.2.3/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part3.java
--- basex-8.1.1/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part3.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part3.java	2015-07-14 10:54:40.000000000 +0000
@@ -9,10 +9,9 @@
 import org.w3c.dom.*;
 
 /**
- * XQJ Example, derived from the XQJ Tutorial
- * <a href="http://www.xquery.com/tutorials/xqj_tutorial">
- * http://www.xquery.com/tutorials/xqj_tutorial</a>
- * from Marc van Cappellen.
+ * XQJ Examples, derived from an
+ * <a href="https://www.progress.com/products/data-integration-suite/data-integration-suite-developer-center/data-integration-suite-tutorials/learning-xquery/introduction-to-the-xquery-api-for-java-xqj-">
+ * XQJ online tutorial</a>.
  *
  * Part 3: Querying Data from XML Files or Java XML APIs.
  *
diff -Nru basex-8.1.1/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part4.java basex-8.2.3/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part4.java
--- basex-8.1.1/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part4.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part4.java	2015-07-14 10:54:40.000000000 +0000
@@ -11,10 +11,9 @@
 import org.xml.sax.helpers.*;
 
 /**
- * XQJ Example, derived from the XQJ Tutorial
- * <a href="http://www.xquery.com/tutorials/xqj_tutorial">
- * http://www.xquery.com/tutorials/xqj_tutorial</a>
- * from Marc van Cappellen.
+ * XQJ Examples, derived from an
+ * <a href="https://www.progress.com/products/data-integration-suite/data-integration-suite-developer-center/data-integration-suite-tutorials/learning-xquery/introduction-to-the-xquery-api-for-java-xqj-">
+ * XQJ online tutorial</a>.
  *
  * Part 4: Processing Results.
  *
diff -Nru basex-8.1.1/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part5.java basex-8.2.3/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part5.java
--- basex-8.1.1/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part5.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part5.java	2015-07-14 10:54:40.000000000 +0000
@@ -6,10 +6,9 @@
 import javax.xml.xquery.*;
 
 /**
- * XQJ Example, derived from the XQJ Tutorial
- * <a href="http://www.xquery.com/tutorials/xqj_tutorial">
- * http://www.xquery.com/tutorials/xqj_tutorial</a>
- * from Marc van Cappellen.
+ * XQJ Examples, derived from an
+ * <a href="https://www.progress.com/products/data-integration-suite/data-integration-suite-developer-center/data-integration-suite-tutorials/learning-xquery/introduction-to-the-xquery-api-for-java-xqj-">
+ * XQJ online tutorial</a>.
  *
  * Part 5: Serializing Results.
  *
diff -Nru basex-8.1.1/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part6.java basex-8.2.3/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part6.java
--- basex-8.1.1/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part6.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part6.java	2015-07-14 10:54:40.000000000 +0000
@@ -3,10 +3,9 @@
 import javax.xml.xquery.*;
 
 /**
- * XQJ Example, derived from the XQJ Tutorial
- * <a href="http://www.xquery.com/tutorials/xqj_tutorial">
- * http://www.xquery.com/tutorials/xqj_tutorial</a>
- * from Marc van Cappellen.
+ * XQJ Examples, derived from an
+ * <a href="https://www.progress.com/products/data-integration-suite/data-integration-suite-developer-center/data-integration-suite-tutorials/learning-xquery/introduction-to-the-xquery-api-for-java-xqj-">
+ * XQJ online tutorial</a>.
  *
  * Part 6: Manipulating Static Context.
  *
diff -Nru basex-8.1.1/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part7.java basex-8.2.3/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part7.java
--- basex-8.1.1/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part7.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part7.java	2015-07-14 10:54:40.000000000 +0000
@@ -4,10 +4,9 @@
 import javax.xml.xquery.*;
 
 /**
- * XQJ Example, derived from the XQJ Tutorial
- * <a href="http://www.xquery.com/tutorials/xqj_tutorial">
- * http://www.xquery.com/tutorials/xqj_tutorial</a>
- * from Marc van Cappellen.
+ * XQJ Examples, derived from an
+ * <a href="https://www.progress.com/products/data-integration-suite/data-integration-suite-developer-center/data-integration-suite-tutorials/learning-xquery/introduction-to-the-xquery-api-for-java-xqj-">
+ * XQJ online tutorial</a>.
  *
  * Part 7: XQuery Type System.
  *
diff -Nru basex-8.1.1/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part8.java basex-8.2.3/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part8.java
--- basex-8.1.1/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part8.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part8.java	2015-07-14 10:54:40.000000000 +0000
@@ -10,10 +10,9 @@
 import org.w3c.dom.*;
 
 /**
- * XQJ Example, derived from the XQJ Tutorial
- * <a href="http://www.xquery.com/tutorials/xqj_tutorial">
- * http://www.xquery.com/tutorials/xqj_tutorial</a>
- * from Marc van Cappellen.
+ * XQJ Examples, derived from an
+ * <a href="https://www.progress.com/products/data-integration-suite/data-integration-suite-developer-center/data-integration-suite-tutorials/learning-xquery/introduction-to-the-xquery-api-for-java-xqj-">
+ * XQJ online tutorial</a>.
  *
  * Part 8: Binding External Variables.
  *
diff -Nru basex-8.1.1/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part9.java basex-8.2.3/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part9.java
--- basex-8.1.1/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part9.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-examples/src/main/java/org/basex/examples/xqj/tutorial/Part9.java	2015-07-14 10:54:40.000000000 +0000
@@ -7,10 +7,9 @@
 import javax.xml.xquery.*;
 
 /**
- * XQJ Example, derived from the XQJ Tutorial
- * <a href="http://www.xquery.com/tutorials/xqj_tutorial">
- * http://www.xquery.com/tutorials/xqj_tutorial</a>
- * from Marc van Cappellen.
+ * XQJ Examples, derived from an
+ * <a href="https://www.progress.com/products/data-integration-suite/data-integration-suite-developer-center/data-integration-suite-tutorials/learning-xquery/introduction-to-the-xquery-api-for-java-xqj-">
+ * XQJ online tutorial</a>.
  *
  * Part 9: Creating XDM Instances.
  *
diff -Nru basex-8.1.1/basex-tests/pom.xml basex-8.2.3/basex-tests/pom.xml
--- basex-8.1.1/basex-tests/pom.xml	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-tests/pom.xml	2015-07-14 10:54:40.000000000 +0000
@@ -8,7 +8,7 @@
   <parent>
     <groupId>org.basex</groupId>
     <artifactId>basex-parent</artifactId>
-    <version>8.1.1</version>
+    <version>8.2.3</version>
     <relativePath>..</relativePath>
   </parent>
 
diff -Nru basex-8.1.1/basex-tests/.settings/checkstyle.xml basex-8.2.3/basex-tests/.settings/checkstyle.xml
--- basex-8.1.1/basex-tests/.settings/checkstyle.xml	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-tests/.settings/checkstyle.xml	2015-07-14 10:54:40.000000000 +0000
@@ -1,12 +1,12 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE module PUBLIC "-//Puppy Crawl//DTD Check Configuration 1.3//EN" "http://www.puppycrawl.com/dtds/configuration_1_3.dtd">
 
-<!--
-    This configuration file was written by the eclipse-cs plugin configuration editor
+<!--
+    This configuration file was written by the eclipse-cs plugin configuration editor
 -->
-<!--
-    Checkstyle-Configuration: BaseX Checkstyle
-    Description: none
+<!--
+    Checkstyle-Configuration: BaseX Checkstyle
+    Description: none
 -->
 <module name="Checker">
   <property name="severity" value="warning"/>
@@ -26,7 +26,7 @@
     <module name="IllegalImport"/>
     <module name="RedundantImport"/>
     <module name="LineLength">
-      <property name="ignorePattern" value="^import"/>
+      <property name="ignorePattern" value="^(import| \*)"/>
       <property name="max" value="100"/>
       <property name="tabWidth" value="2"/>
     </module>
@@ -50,7 +50,6 @@
     </module>
     <module name="ModifierOrder"/>
     <module name="RedundantModifier"/>
-    <module name="AvoidNestedBlocks"/>
     <module name="EqualsHashCode">
       <property name="severity" value="ignore"/>
       <metadata name="net.sf.eclipsecs.core.lastEnabledSeverity" value="inherit"/>
diff -Nru basex-8.1.1/basex-tests/src/main/java/org/basex/tests/bxapi/xdm/XdmValue.java basex-8.2.3/basex-tests/src/main/java/org/basex/tests/bxapi/xdm/XdmValue.java
--- basex-8.1.1/basex-tests/src/main/java/org/basex/tests/bxapi/xdm/XdmValue.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-tests/src/main/java/org/basex/tests/bxapi/xdm/XdmValue.java	2015-07-14 10:54:40.000000000 +0000
@@ -9,7 +9,6 @@
 import org.basex.query.value.seq.*;
 import org.basex.query.value.type.*;
 import org.basex.tests.bxapi.*;
-import org.basex.util.*;
 
 /**
  * Wrapper for representing XQuery values.
@@ -33,7 +32,7 @@
    * @return node name
    */
   public String getBaseURI() {
-    throw Util.notExpected("Item must be a node: " + internal());
+    throw new XQueryException(new QueryException("Item must be a node: " + internal()));
   }
 
   /**
@@ -41,7 +40,7 @@
    * @return node name
    */
   public QName getName() {
-    throw Util.notExpected("Item must be a node: " + internal());
+    throw new XQueryException(new QueryException("Item must be a node: " + internal()));
   }
 
   /**
@@ -49,7 +48,8 @@
    * @return node name
    */
   public boolean getBoolean() {
-    throw Util.notExpected("Value has no boolean representation: " + internal());
+    throw new XQueryException(new QueryException(
+        "Value has no boolean representation: " + internal()));
   }
 
   /**
@@ -60,7 +60,8 @@
     try {
       return Long.parseLong(getString());
     } catch(final NumberFormatException ex) {
-      throw Util.notExpected("Value has no integer representation: " + internal());
+      throw new XQueryException(new QueryException(
+          "Value has no integer representation: " + internal()));
     }
   }
 
@@ -69,7 +70,8 @@
    * @return node name
    */
   public String getString() {
-    throw Util.notExpected("Value has no string representation: " + internal());
+    throw new XQueryException(new QueryException(
+        "Value has no string representation: " + internal()));
   }
 
   /**
diff -Nru basex-8.1.1/basex-tests/src/main/java/org/basex/tests/bxapi/XQuery.java basex-8.2.3/basex-tests/src/main/java/org/basex/tests/bxapi/XQuery.java
--- basex-8.1.1/basex-tests/src/main/java/org/basex/tests/bxapi/XQuery.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-tests/src/main/java/org/basex/tests/bxapi/XQuery.java	2015-07-14 10:54:40.000000000 +0000
@@ -6,7 +6,6 @@
 import javax.xml.namespace.*;
 
 import org.basex.core.Context;
-import org.basex.io.serial.*;
 import org.basex.query.*;
 import org.basex.query.expr.*;
 import org.basex.query.func.*;
@@ -242,11 +241,11 @@
   }
 
   /**
-   * Returns serialization properties.
-   * @return serialization properties
+   * Returns the query processor.
+   * @return query processor
    */
-  public SerializerOptions serializer() {
-    return qp.qc.serParams();
+  public QueryProcessor qp() {
+    return qp;
   }
 
   @Override
diff -Nru basex-8.1.1/basex-tests/src/main/java/org/basex/tests/w3c/QT3TS.java basex-8.2.3/basex-tests/src/main/java/org/basex/tests/w3c/QT3TS.java
--- basex-8.1.1/basex-tests/src/main/java/org/basex/tests/w3c/QT3TS.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-tests/src/main/java/org/basex/tests/w3c/QT3TS.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,7 +1,7 @@
 package org.basex.tests.w3c;
 
 import static org.basex.tests.w3c.QT3Constants.*;
-import static org.basex.util.Prop.NL;
+import static org.basex.util.Prop.*;
 import static org.basex.util.Token.*;
 
 import java.io.*;
@@ -313,16 +313,11 @@
     }
 
     final QT3Result returned = new QT3Result();
+    returned.env = env;
+
     try {
+      environment(query, env);
       if(env != null) {
-        // bind namespaces
-        for(final HashMap<String, String> ns : env.namespaces) {
-          query.namespace(ns.get(PREFIX), ns.get(URI));
-        }
-        // bind variables
-        for(final HashMap<String, String> par : env.params) {
-          query.bind(par.get(NNAME), new XQuery(par.get(SELECT), ctx).value());
-        }
         // bind documents
         for(final HashMap<String, String> src : env.sources) {
           // add document reference
@@ -337,7 +332,8 @@
         }
         // bind resources
         for(final HashMap<String, String> src : env.resources) {
-          query.addResource(src.get(URI), file(base, src.get(FILE)), src.get(ENCODING));
+          query.addResource(src.get(URI), file(base, src.get(FILE)),
+              src.get(QT3Constants.ENCODING));
         }
         // bind collections
         query.addCollection(env.collURI, env.collSources.toArray());
@@ -359,7 +355,7 @@
 
       // run query
       returned.value = query.value();
-      returned.sprop = query.serializer();
+      returned.query = query;
     } catch(final XQueryException ex) {
       returned.xqerror = ex;
       returned.value = null;
@@ -388,8 +384,7 @@
       } else if(returned.xqerror != null) {
         res = returned.xqerror.getCode() + ": " + returned.xqerror.getLocalizedMessage();
       } else {
-        returned.sprop.set(SerializerOptions.OMIT_XML_DECLARATION, YesNo.YES);
-        res = serialize(returned.value, returned.sprop);
+        res = serialize(returned);
       }
     } catch(final XQueryException ex) {
       res = ex.getCode() + ": " + ex.getLocalizedMessage();
@@ -410,13 +405,33 @@
   }
 
   /**
+   * Assigns the query environment.
+   * @param query query
+   * @param env environment
+   * @return query;
+   */
+  private XQuery environment(XQuery query, QT3Env env) {
+    if(env != null) {
+      // bind namespaces
+      for(final HashMap<String, String> ns : env.namespaces) {
+        query.namespace(ns.get(PREFIX), ns.get(URI));
+      }
+      // bind variables
+      for(final HashMap<String, String> par : env.params) {
+        query.bind(par.get(NNAME), new XQuery(par.get(SELECT), ctx).value());
+      }
+    }
+    return query;
+  }
+
+  /**
    * Normalizes special characters in the specified string.
    * @param in input string
    * @return result
    */
   private String normSpecial(final String in) {
-    // return QueryProcessor.removeComments(in, maxout);
-    return in.replace("\n", "%0A").replace("\r", "%0D").replace("\t", "%09");
+    return in.replaceAll("<\\?xml.*?>", "").replace("\n", "%0A").replace("\r", "%0D").
+        replace("\t", "%09");
   }
 
   /** Flags for dependencies that are not supported. */
@@ -462,49 +477,49 @@
 
   /**
    * Tests the result of a test case.
-   * @param returned resulting value
+   * @param result query result
    * @param expected expected result
    * @return {@code null} if test was successful; otherwise, expected test suite result
    */
-  private String test(final QT3Result returned, final XdmValue expected) {
+  private String test(final QT3Result result, final XdmValue expected) {
     final String type = expected.getName().getLocalPart();
-    final XdmValue value = returned.value;
-
     try {
       String msg;
       if(type.equals("error")) {
-        msg = assertError(returned, expected);
+        msg = assertError(result, expected);
       } else if(type.equals("assert-serialization-error")) {
-        msg = assertSerializationError(returned, expected, returned.sprop);
+        msg = assertSerializationError(result, expected);
       } else if(type.equals("all-of")) {
-        msg = allOf(returned, expected);
+        msg = allOf(result, expected);
+      } else if(type.equals("not")) {
+        msg = not(result, expected);
       } else if(type.equals("any-of")) {
-        msg = anyOf(returned, expected);
-      } else if(value != null) {
+        msg = anyOf(result, expected);
+      } else if(result.value != null) {
         if(type.equals("assert")) {
-          msg = assertQuery(value, expected);
+          msg = assertQuery(result, expected);
         } else if(type.equals("assert-count")) {
-          msg = assertCount(value, expected);
+          msg = assertCount(result, expected);
         } else if(type.equals("assert-deep-eq")) {
-          msg = assertDeepEq(value, expected);
+          msg = assertDeepEq(result, expected);
         } else if(type.equals("assert-empty")) {
-          msg = assertEmpty(value);
+          msg = assertEmpty(result);
         } else if(type.equals("assert-eq")) {
-          msg = assertEq(value, expected);
+          msg = assertEq(result, expected);
         } else if(type.equals("assert-false")) {
-          msg = assertBoolean(value, false);
+          msg = assertBoolean(result, false);
         } else if(type.equals("assert-permutation")) {
-          msg = assertPermutation(value, expected);
+          msg = assertPermutation(result, expected);
         } else if(type.equals("assert-xml")) {
-          msg = assertXML(value, expected);
+          msg = assertXML(result, expected);
         } else if(type.equals("serialization-matches")) {
-          msg = serializationMatches(value, expected, returned.sprop);
+          msg = serializationMatches(result, expected);
         } else if(type.equals("assert-string-value")) {
-          msg = assertStringValue(value, expected);
+          msg = assertStringValue(result, expected);
         } else if(type.equals("assert-true")) {
-          msg = assertBoolean(value, true);
+          msg = assertBoolean(result, true);
         } else if(type.equals("assert-type")) {
-          msg = assertType(value, expected);
+          msg = assertType(result, expected);
         } else {
           msg = "Test type not supported: " + type;
         }
@@ -520,16 +535,16 @@
 
   /**
    * Tests error.
-   * @param returned query result
+   * @param result query result
    * @param expected expected result
    * @return optional expected test suite result
    */
-  private String assertError(final QT3Result returned, final XdmValue expected) {
+  private String assertError(final QT3Result result, final XdmValue expected) {
     final String exp = asString('@' + CODE, expected);
-    if(returned.xqerror == null) return exp;
+    if(result.xqerror == null) return exp;
     if(!errors || exp.equals("*")) return null;
 
-    final QNm resErr = returned.xqerror.getException().qname();
+    final QNm resErr = result.xqerror.getException().qname();
 
     String name = exp, uri = string(QueryText.ERROR_URI);
     final Matcher m = BIND.matcher(exp);
@@ -542,15 +557,30 @@
   }
 
   /**
+   * Tests not.
+   * @param result query result
+   * @param exp expected result
+   * @return optional expected test suite result
+   */
+  private String not(final QT3Result result, final XdmValue exp) {
+    final TokenBuilder tb = new TokenBuilder();
+    for(final XdmItem it : environment(new XQuery("*", ctx), result.env).context(exp)) {
+      final String msg = test(result, it);
+      if(msg != null) tb.add(tb.isEmpty() ? "" : ", ").add(msg);
+    }
+    return tb.isEmpty() ? "Error" : null;
+  }
+
+  /**
    * Tests all-of.
-   * @param res resulting value
+   * @param result query result
    * @param exp expected result
    * @return optional expected test suite result
    */
-  private String allOf(final QT3Result res, final XdmValue exp) {
+  private String allOf(final QT3Result result, final XdmValue exp) {
     final TokenBuilder tb = new TokenBuilder();
-    for(final XdmItem it : new XQuery("*", ctx).context(exp)) {
-      final String msg = test(res, it);
+    for(final XdmItem it : environment(new XQuery("*", ctx), result.env).context(exp)) {
+      final String msg = test(result, it);
       if(msg != null) tb.add(tb.isEmpty() ? "" : ", ").add(msg);
     }
     return tb.isEmpty() ? null : tb.toString();
@@ -558,14 +588,14 @@
 
   /**
    * Tests any-of.
-   * @param res resulting value
+   * @param result query result
    * @param exp expected result
    * @return optional expected test suite result
    */
-  private String anyOf(final QT3Result res, final XdmValue exp) {
+  private String anyOf(final QT3Result result, final XdmValue exp) {
     final TokenBuilder tb = new TokenBuilder();
-    for(final XdmItem it : new XQuery("*", ctx).context(exp)) {
-      final String msg = test(res, it);
+    for(final XdmItem it : environment(new XQuery("*", ctx), result.env).context(exp)) {
+      final String msg = test(result, it);
       if(msg == null) return null;
       tb.add(tb.isEmpty() ? "" : ", ").add(msg);
     }
@@ -574,15 +604,16 @@
 
   /**
    * Tests assertion.
-   * @param returned resulting value
+   * @param result query result
    * @param expected expected result
    * @return optional expected test suite result
    */
-  private String assertQuery(final XdmValue returned, final XdmValue expected) {
+  private String assertQuery(final QT3Result result, final XdmValue expected) {
     final String exp = expected.getString();
     try {
       final String qu = "declare variable $result external; " + exp;
-      return new XQuery(qu, ctx).bind("$result", returned).value().getBoolean() ? null : exp;
+      return environment(new XQuery(qu, ctx), result.env).bind("$result", result.value).
+          value().getBoolean() ? null : exp;
     } catch(final XQueryException ex) {
       // should not occur
       return ex.getException().getMessage();
@@ -591,27 +622,28 @@
 
   /**
    * Tests count.
-   * @param returned resulting value
+   * @param result query result
    * @param expected expected result
    * @return optional expected test suite result
    */
-  private static String assertCount(final XdmValue returned, final XdmValue expected) {
+  private static String assertCount(final QT3Result result, final XdmValue expected) {
     final long exp = expected.getInteger();
-    final int res = returned.size();
+    final int res = result.value.size();
     return exp == res ? null : Util.info("% items (% found)", exp, res);
   }
 
   /**
    * Tests equality.
-   * @param returned resulting value
+   * @param result query result
    * @param expected expected result
    * @return optional expected test suite result
    */
-  private String assertEq(final XdmValue returned, final XdmValue expected) {
+  private String assertEq(final QT3Result result, final XdmValue expected) {
     final String exp = expected.getString();
     try {
       final String qu = "declare variable $returned external; $returned eq " + exp;
-      return new XQuery(qu, ctx).bind("$returned", returned).value().getBoolean() ? null : exp;
+      return environment(new XQuery(qu, ctx), result.env).bind("$returned", result.value).
+          value().getBoolean() ? null : exp;
     } catch(final XQueryException err) {
       // numeric overflow: try simple string comparison
       return err.getCode().equals("FOAR0002") && exp.equals(expected.getString())
@@ -621,29 +653,29 @@
 
   /**
    * Tests deep equals.
-   * @param returned resulting value
+   * @param result query result
    * @param expected expected result
    * @return optional expected test suite result
    */
-  private String assertDeepEq(final XdmValue returned, final XdmValue expected) {
-    final XdmValue exp = new XQuery(expected.getString(), ctx).value();
-    return exp.deepEqual(returned) ? null : exp.toString();
+  private String assertDeepEq(final QT3Result result, final XdmValue expected) {
+    final XdmValue exp = environment(new XQuery(expected.getString(), ctx), result.env).value();
+    return exp.deepEqual(result.value) ? null : exp.toString();
   }
 
   /**
    * Tests permutation.
-   * @param returned resulting value
+   * @param result query result
    * @param expected expected result
    * @return optional expected test suite result
    */
-  private String assertPermutation(final XdmValue returned, final XdmValue expected) {
+  private String assertPermutation(final QT3Result result, final XdmValue expected) {
     // cache expected results
     final HashSet<String> exp = new HashSet<>();
-    for(final XdmItem it : new XQuery(expected.getString(), ctx))
+    for(final XdmItem it : environment(new XQuery(expected.getString(), ctx), result.env))
       exp.add(it.getString());
     // cache actual results
     final HashSet<String> res = new HashSet<>();
-    for(final XdmItem it : returned) res.add(it.getString());
+    for(final XdmItem it : result.value) res.add(it.getString());
 
     if(exp.size() != res.size())
       return Util.info("% results (found: %)", exp.size(), res.size());
@@ -660,11 +692,11 @@
 
   /**
    * Tests the serialized result.
-   * @param returned resulting value
+   * @param result query result
    * @param expected expected result
    * @return optional expected test suite result
    */
-  private String assertXML(final XdmValue returned, final XdmValue expected) {
+  private String assertXML(final QT3Result result, final XdmValue expected) {
     final String file = asString("@file", expected);
     final boolean norm = asBoolean("@normalize-space=('true','1')", expected);
     final boolean pref = asBoolean("@ignore-prefixes=('true','1')", expected);
@@ -675,6 +707,7 @@
       exp = normNL(exp);
       if(norm) exp = string(normalize(token(exp)));
 
+      final XdmValue returned = result.value;
       final String res = normNL(
           asString("serialize(., map{ 'indent':'no','method':'xml' })", returned));
       if(exp.equals(res)) return null;
@@ -695,54 +728,45 @@
 
   /**
    * Tests the serialized result.
-   * @param returned resulting value
+   * @param result query result
    * @param expected expected result
-   * @param sprop serialization properties
    * @return optional expected test suite result
    */
-  private String serializationMatches(final XdmValue returned, final XdmValue expected,
-      final SerializerOptions sprop) {
-
-    final String exp = expected.getString();
-    final String flags = asString("@flags", expected);
-    final int flgs = flags.contains("i") ? Pattern.CASE_INSENSITIVE : 0;
-    final Pattern pat = Pattern.compile("^.*" + exp + ".*", flgs |
-        Pattern.MULTILINE | Pattern.DOTALL);
-
-    if(sprop.get(SerializerOptions.METHOD) == SerialMethod.ADAPTIVE)
-      sprop.set(SerializerOptions.OMIT_XML_DECLARATION, YesNo.YES);
-
+  private String serializationMatches(final QT3Result result, final XdmValue expected) {
     try {
-      return pat.matcher("^.*" + serialize(returned, sprop) + ".*").matches() ? null : exp;
-    } catch(final IOException ex) {
-      return Util.info("% (found: %)", exp, ex);
+      final String flags = asString("@flags", expected);
+      final XdmValue ret = XdmValue.get(Str.get(serialize(result)));
+      final String qu = "declare variable $returned external;"
+          + "declare variable $expected external;"
+          + "matches($returned, string($expected), '" + flags + "')";
+
+      return environment(new XQuery(qu, ctx), result.env).bind("returned", ret).
+          bind("expected", expected).value().getBoolean() ? null : expected.getString();
+    } catch(final Exception err) {
+      return Util.info("% (found: %)", expected.getString(), err);
     }
   }
 
-
   /**
    * Tests a serialization error.
-   * @param returned result
+   * @param result returned result
    * @param expected expected result
-   * @param sprop serialization properties
    * @return optional expected test suite result
    */
-  private String assertSerializationError(final QT3Result returned, final XdmValue expected,
-      final SerializerOptions sprop) {
-
+  private String assertSerializationError(final QT3Result result, final XdmValue expected) {
     final String expCode = asString('@' + CODE, expected);
-    if(returned.xqerror != null) {
+    if(result.xqerror != null) {
       if(!errors || expCode.equals("*")) return null;
-      final String resCode = string(returned.xqerror.getException().qname().local());
+      final String resCode = string(result.xqerror.getException().qname().local());
       if(resCode.equals(expCode)) return null;
     }
 
     try {
-      if(returned.value != null) serialize(returned.value, sprop);
+      if(result.value != null) serialize(result);
       return expCode;
-    } catch(final QueryIOException ex) {
+    } catch(final QueryException ex) {
       if(!errors || expCode.equals("*")) return null;
-      final String resCode = string(ex.getCause().qname().local());
+      final String resCode = string(ex.qname().local());
       if(resCode.equals(expCode)) return null;
       return Util.info("% (found: %)", expCode, ex);
     } catch(final IOException ex) {
@@ -752,28 +776,30 @@
 
   /**
    * Serializes values.
-   * @param returned resulting value
-   * @param sprop serialization properties
+   * @param result query result
    * @return optional expected test suite result
+   * @throws QueryException query exception
    * @throws IOException I/O exception
    */
-  private static String serialize(final XdmValue returned, final SerializerOptions sprop)
-      throws IOException {
-
-    final ArrayOutput ao = new ArrayOutput();
-    try(final Serializer ser = Serializer.get(ao, sprop)) {
-      for(final Item it : returned.internal()) ser.serialize(it);
+  private static String serialize(final QT3Result result) throws QueryException, IOException {
+    try {
+      final ArrayOutput ao = new ArrayOutput();
+      try(final Serializer ser = result.query.qp().getSerializer(ao)) {
+        for(final Item it : result.value.internal()) ser.serialize(it);
+      }
+      return ao.toString();
+    } catch(final QueryIOException ex) {
+      throw ex.getCause();
     }
-    return ao.toString();
   }
 
   /**
    * Tests string value.
-   * @param returned resulting value
+   * @param result query result
    * @param expected expected result
    * @return optional expected test suite result
    */
-  private String assertStringValue(final XdmValue returned, final XdmValue expected) {
+  private String assertStringValue(final QT3Result result, final XdmValue expected) {
     String exp = expected.getString();
     // normalize space
     final boolean norm = asBoolean("@normalize-space=('true','1')", expected);
@@ -781,7 +807,7 @@
 
     final TokenBuilder tb = new TokenBuilder();
     int c = 0;
-    for(final XdmItem it : returned) {
+    for(final XdmItem it : result.value) {
       if(c++ != 0) tb.add(' ');
       tb.add(it.getString());
     }
@@ -792,35 +818,38 @@
 
   /**
    * Tests boolean.
-   * @param returned resulting value
+   * @param result query result
    * @param expected expected
    * @return optional expected test suite result
    */
-  private static String assertBoolean(final XdmValue returned, final boolean expected) {
+  private static String assertBoolean(final QT3Result result, final boolean expected) {
+    final XdmValue returned = result.value;
     return returned.getType().eq(SeqType.BLN) && returned.getBoolean() == expected ?
         null : Util.info(expected);
   }
 
   /**
    * Tests empty sequence.
-   * @param value resulting value
+   * @param result query result
    * @return optional expected test suite result
    */
-  private static String assertEmpty(final XdmValue value) {
-    return value == XdmEmpty.EMPTY ? null : "";
+  private static String assertEmpty(final QT3Result result) {
+    return result.value == XdmEmpty.EMPTY ? null : "";
   }
 
   /**
    * Tests type.
-   * @param returned resulting value
+   * @param result query result
    * @param expected expected result
    * @return optional expected test suite result
    */
-  private String assertType(final XdmValue returned, final XdmValue expected) {
+  private String assertType(final QT3Result result, final XdmValue expected) {
     final String exp = expected.getString();
     try {
       final String qu = "declare variable $returned external; $returned instance of " + exp;
-      final XQuery query = new XQuery(qu, ctx);
+      final XQuery query = environment(new XQuery(qu, ctx), result.env);
+
+      final XdmValue returned = result.value;
       return query.bind("returned", returned).value().getBoolean() ? null :
         Util.info("Type '%' (found: '%')", exp, returned.getType().toString());
     } catch(final XQueryException ex) {
@@ -953,8 +982,10 @@
    * Structure for storing XQuery results.
    */
   static class QT3Result {
-    /** Serialization parameters. */
-    SerializerOptions sprop;
+    /** Test environment. */
+    QT3Env env;
+    /** Query instance. */
+    XQuery query;
     /** Query result. */
     XdmValue value;
     /** Query exception. */
diff -Nru basex-8.1.1/basex-tests/src/test/java/org/basex/performance/UpdIndexRandomTest.java basex-8.2.3/basex-tests/src/test/java/org/basex/performance/UpdIndexRandomTest.java
--- basex-8.1.1/basex-tests/src/test/java/org/basex/performance/UpdIndexRandomTest.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-tests/src/test/java/org/basex/performance/UpdIndexRandomTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,81 @@
+package org.basex.performance;
+
+import static org.basex.query.func.Function.*;
+import static org.junit.Assert.*;
+
+import java.util.*;
+
+import org.basex.*;
+import org.basex.core.*;
+import org.basex.core.cmd.*;
+import org.basex.core.cmd.Set;
+import org.basex.util.*;
+import org.basex.util.list.*;
+import org.junit.*;
+import org.junit.Test;
+
+/**
+ * This test class performs random incremental updates with random documents.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Christian Gruen
+ */
+public final class UpdIndexRandomTest extends SandboxTest {
+  /** Number of different documents. */
+  private static final int DOCS = 20;
+  /** Number of runs. */
+  private static final int RUNS = 500;
+
+  /**
+   * Initializes the test.
+   * @throws Exception exception
+   */
+  @Before
+  public void init() throws Exception {
+    new Set(MainOptions.UPDINDEX, true).execute(context);
+    new Set(MainOptions.ATTRINDEX, false).execute(context);
+    new CreateDB(NAME).execute(context);
+  }
+
+  /**
+   * Incremental test.
+   * @throws Exception exception
+   */
+  @Test
+  public void insertInto() throws Exception {
+    final Random rnd = new Random(0);
+
+    // create random words
+    int cap = 1000;
+    final StringList words = new StringList(cap);
+    for(int w = 0; w < cap; w++) {
+      final int r = 1 + rnd.nextInt(10);
+      final TokenBuilder tmp = new TokenBuilder(r);
+      for(int i = 0; i < r; i++) tmp.add('A' + rnd.nextInt(26));
+      words.add(tmp.toString());
+    }
+
+    for(int r = 0; r < RUNS; r++) {
+      final String path = "doc" + rnd.nextInt(DOCS);
+      // create random document
+      final TokenBuilder doc = new TokenBuilder("<xml>");
+
+      final int offset = rnd.nextInt(cap - DOCS);
+      for(int i = 0; i < DOCS; i++) doc.add("<a>").add(words.get(offset + i)).add("</a>");
+      doc.add("</xml>");
+      new Replace(path, doc.toString()).execute(context);
+
+      for(int d = 0; d < DOCS; d++) {
+        final String word = words.get(offset + d);
+        final String query = _DB_OPEN.args(NAME, path) + "//a[text() = '" + word + "']";
+        final String expected = "<a>" + word + "</a>";
+        final String result = new XQuery(query).execute(context);
+        if(!result.startsWith(expected)) {
+          fail(new TokenBuilder("\nExpected: " + expected +
+              "\nResult: " + result + "\nRun: " + r + "\nDoc: " + d +
+              "\nQuery: " + query + "\nDocument: " + doc).toString());
+        }
+      }
+    }
+  }
+}
diff -Nru basex-8.1.1/basex-tests/src/test/java/org/basex/performance/UpdIndexTest.java basex-8.2.3/basex-tests/src/test/java/org/basex/performance/UpdIndexTest.java
--- basex-8.1.1/basex-tests/src/test/java/org/basex/performance/UpdIndexTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-tests/src/test/java/org/basex/performance/UpdIndexTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -156,11 +156,11 @@
    * Runs the specified query.
    * @param query query string
    * @return result
-   * @throws QueryException database exception
+   * @throws Exception exception
    */
-  protected static String query(final String query) throws QueryException {
+  protected static String query(final String query) throws Exception {
     try(final QueryProcessor qp = new QueryProcessor(query, context)) {
-      return qp.execute().toString().replaceAll("(\\r|\\n) *", "");
+      return normNL(qp.value().serialize().toString());
     }
   }
 
@@ -168,9 +168,9 @@
    * Checks if a query yields the specified string.
    * @param query query to be run
    * @param result query result
-   * @throws QueryException database exception
+   * @throws Exception exception
    */
-  protected static void query(final String query, final Object result) throws QueryException {
+  protected static void query(final String query, final Object result) throws Exception {
     assertEquals(result.toString(), query(query));
   }
 }
diff -Nru basex-8.1.1/basex-tests/src/test/java/org/basex/performance/XMarkTest.java basex-8.2.3/basex-tests/src/test/java/org/basex/performance/XMarkTest.java
--- basex-8.1.1/basex-tests/src/test/java/org/basex/performance/XMarkTest.java	1970-01-01 00:00:00.000000000 +0000
+++ basex-8.2.3/basex-tests/src/test/java/org/basex/performance/XMarkTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -0,0 +1,208 @@
+package org.basex.performance;
+
+import static org.basex.core.Text.*;
+
+import java.io.*;
+import java.math.*;
+
+import org.basex.*;
+import org.basex.api.client.*;
+import org.basex.core.*;
+import org.basex.core.cmd.*;
+import org.basex.core.users.*;
+import org.basex.io.*;
+import org.basex.util.*;
+import org.basex.util.list.*;
+import org.junit.*;
+import org.junit.Test;
+
+/**
+ * Runs the XMark tests.
+ *
+ * @author BaseX Team 2005-15, BSD License
+ * @author Christian Gruen
+ */
+public final class XMarkTest {
+  /** Name of database. */
+  private static final String DB = "111mb";
+
+  /** Test directory. */
+  private static final IOFile DIR = new IOFile(Prop.TMP, "XMark");
+  /** Output file. */
+  private static final IOFile FILE = new IOFile(DIR, "master- " + DB + ".graph");
+
+  /** Maximum time per query (ms). */
+  private static final int MAX = 2000;
+
+  /** Queries. */
+  private static final String[] QUERIES = {
+    "let $auction := . return for $b in $auction/site/people/person[@id = \"person0\"]"
+    + "return $b/name/text()",
+    "let $auction := . return for $b in $auction/site/open_auctions/open_auction "
+    + "return <increase>{$b/bidder[1]/increase/text()}</increase>",
+    "let $auction := . return for $b in $auction/site/open_auctions/open_auction "
+    + "where zero-or-one($b/bidder[1]/increase/text()) * 2 <= $b/bidder[last()]/increase/text() "
+    + "return <increase first=\"{$b/bidder[1]/increase/text()}\" "
+    + "last=\"{$b/bidder[last()]/increase/text()}\"/>",
+    "let $auction := . return for $b in $auction/site/open_auctions/open_auction "
+    + "where some $pr1 in $b/bidder/personref[@person = \"person20\"], "
+    + "$pr2 in $b/bidder/personref[@person = \"person51\"] satisfies $pr1 << $pr2 "
+    + "return <history>{$b/reserve/text()}</history>",
+    "let $auction := . return count( for $i in $auction/site/closed_auctions/closed_auction "
+    + "where $i/price/text() >= 40 return $i/price )",
+    "let $auction := . return for $b in $auction//site/regions return count($b//item)",
+    "let $auction := . return for $p in $auction/site "
+    + "return count($p//description) + count($p//annotation) + count($p//emailaddress)",
+    "let $auction := . return for $p in $auction/site/people/person "
+    + "let $a := for $t in $auction/site/closed_auctions/closed_auction "
+    + "where $t/buyer/@person = $p/@id return $t "
+    + "return <item person=\"{$p/name/text()}\">{count($a)}</item>",
+    "let $auction := . return let $ca := $auction/site/closed_auctions/closed_auction "
+    + "return let $ei := $auction/site/regions/europe/item for $p in $auction/site/people/person "
+    + "let $a := for $t in $ca where $p/@id = $t/buyer/@person return "
+    + "let $n := for $t2 in $ei where $t/itemref/@item = $t2/@id return $t2 "
+    + "return <item>{$n/name/text()}</item> return <person name=\"{$p/name/text()}\">{$a}</person>",
+    "let $auction := . return for $i in "
+    + "distinct-values($auction/site/people/person/profile/interest/@category) "
+    + "let $p := for $t in $auction/site/people/person where $t/profile/interest/@category = $i "
+    + "return <personne> <statistiques> <sexe>{$t/profile/gender/text()}</sexe> "
+    + "<age>{$t/profile/age/text()}</age> <education>{$t/profile/education/text()}</education> "
+    + "<revenu>{fn:data($t/profile/@income)}</revenu> </statistiques> <coordonnees> "
+    + "<nom>{$t/name/text()}</nom> <rue>{$t/address/street/text()}</rue> "
+    + "<ville>{$t/address/city/text()}</ville> <pays>{$t/address/country/text()}</pays> "
+    + "<reseau> <courrier>{$t/emailaddress/text()}</courrier> "
+    + "<pagePerso>{$t/homepage/text()}</pagePerso> </reseau> </coordonnees> "
+    + "<cartePaiement>{$t/creditcard/text()}</cartePaiement> </personne> "
+    + "return <categorie>{<id>{$i}</id>, $p}</categorie>",
+    "let $auction := . return for $p in $auction/site/people/person let $l := "
+    + "for $i in $auction/site/open_auctions/open_auction/initial "
+    + "where $p/profile/@income > 5000 * exactly-one($i/text()) "
+    + "return $i return <items name=\"{$p/name/text()}\">{count($l)}</items>",
+    "let $auction := . return for $p in $auction/site/people/person let $l := "
+    + "for $i in $auction/site/open_auctions/open_auction/initial "
+    + "where $p/profile/@income > 5000 * exactly-one($i/text()) return $i "
+    + "where $p/profile/@income > 50000 "
+    + "return <items person=\"{$p/profile/@income}\">{count($l)}</items>",
+    "let $auction := . return for $i in $auction/site/regions/australia/item "
+    + "return <item name=\"{$i/name/text()}\">{$i/description}</item>",
+    "let $auction := . return for $i in $auction/site//item "
+    + "where contains(string(exactly-one($i/description)), \"gold\") return $i/name/text()",
+    "let $auction := . return for $a in $auction/site/closed_auctions/closed_auction/annotation/"
+    + "description/parlist/listitem/parlist/listitem/text/emph/keyword/text() "
+    + "return <text>{$a}</text>",
+    "let $auction := . return for $a in $auction/site/closed_auctions/closed_auction "
+    + "where not( empty( $a/annotation/description/parlist/listitem/parlist/listitem/text/emph/"
+    + "keyword/text() ) ) return <person id=\"{$a/seller/@person}\"/>",
+    "let $auction := . return for $p in $auction/site/people/person "
+    + "where empty($p/homepage/text()) return <person name=\"{$p/name/text()}\"/>",
+    "declare namespace local = \"http://www.foobar.org\"; declare function "
+    + "local:convert($v as xs:decimal?) as xs:decimal? { 2.20371 * $v (: convert Dfl to Euro :) }; "
+    + "let $auction := . return for $i in $auction/site/open_auctions/open_auction "
+    + "return local:convert(zero-or-one($i/reserve))",
+    "let $auction := . return for $b in $auction/site/regions//item let $k := $b/name/text() "
+    + "order by zero-or-one($b/location) ascending empty greatest return "
+    + "<item name=\"{$k}\">{$b/location/text()}</item>",
+    "let $auction := . return <result> <preferred> {count($auction/site/people/person/profile"
+    + "[@income >= 100000])} </preferred> <standard> { count( $auction/site/people/person/"
+    + "profile[@income < 100000 and @income >= 30000] ) } </standard> <challenge> {"
+    + "count($auction/site/people/person/profile[@income < 30000])} </challenge> <na> { "
+    + "count( for $p in $auction/site/people/person where empty($p/profile/@income) return $p ) } "
+    + "</na> </result>"
+  };
+  /** Queries to exclude. */
+  private static final IntList EXCLUDE = new IntList().add(8, 9, 10, 11, 12);
+
+  /** Server flag. */
+  private static BaseXServer server;
+
+  /**
+   * Initializes the tests.
+   * @throws Exception any exception
+   */
+  @BeforeClass
+  public static void init() throws Exception {
+    // only start server if it is not already running
+    if(!BaseXServer.ping(StaticOptions.HOST.value(), StaticOptions.PORT.value()))
+      server = new BaseXServer();
+    try(final ClientSession cs = createClient()) {
+      if(!Boolean.valueOf(cs.query("db:exists('" + DB + "')").execute())) {
+        throw new BaseXException("Database '" + DB + "' was not found.");
+      }
+    }
+  }
+
+  /**
+   * Initializes the tests.
+   * @throws Exception any exception
+   */
+  @BeforeClass
+  public static void close() throws Exception {
+    // only stop server if it has not been running before starting the tests
+    if(server != null) server.stop();
+  }
+
+
+  /**
+   * Runs all tests and generates some test output.
+   * @throws Exception any exception
+   */
+  @Test
+  public void test() throws Exception {
+    final TokenBuilder tb = new TokenBuilder().add(DB).add(Prop.NL);
+
+    try(final ClientSession cs = createClient()) {
+      cs.execute(new Open(DB));
+
+      // ignore first run
+      System.out.println("Warming up...");
+      for(int i = 1; i <= 20; i++) {
+        if(!EXCLUDE.contains(i)) {
+          try(final ClientQuery cq = cs.query(QUERIES[i - 1])) {
+            final Performance p = new Performance();
+            cq.execute();
+            System.out.println(i + ": " + p);
+          }
+        }
+      }
+
+      System.out.println(Prop.NL + "Testing...");
+      for(int i = 1; i <= 20; i++) {
+        tb.add(String.format("%02d", i)).add("  ");
+        final BigDecimal max = BigDecimal.valueOf(MAX);
+        try(final ClientQuery cq = cs.query(QUERIES[i - 1])) {
+          if(EXCLUDE.contains(i)) {
+            tb.add("1000000");
+          } else {
+            double min = Double.MAX_VALUE;
+            BigDecimal total = BigDecimal.valueOf(0);
+            int r = 0;
+            while(total.compareTo(max) < 0) {
+              final Performance p = new Performance();
+              cq.execute();
+              final double t = Double.parseDouble(p.getTime().replaceAll(" .*", ""));
+              total = total.add(BigDecimal.valueOf(t));
+              min = Math.min(min, t);
+              r++;
+            }
+            tb.add(Double.toString(min));
+            System.out.println(i + ": " + min + " (" + r + " runs, stopped at " + total + " ms)");
+          }
+        }
+        tb.add(Prop.NL);
+      }
+    }
+
+    DIR.md();
+    FILE.write(tb.finish());
+  }
+
+  /**
+   * Creates a client instance.
+   * @return client instance
+   * @throws IOException I/O exception
+   */
+  private static ClientSession createClient() throws IOException {
+    return new ClientSession(S_LOCALHOST, StaticOptions.PORT.value(),
+        UserText.ADMIN, UserText.ADMIN);
+  }
+}
diff -Nru basex-8.1.1/basex-tests/src/test/java/org/basex/SandboxTest.java basex-8.2.3/basex-tests/src/test/java/org/basex/SandboxTest.java
--- basex-8.1.1/basex-tests/src/test/java/org/basex/SandboxTest.java	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/basex-tests/src/test/java/org/basex/SandboxTest.java	2015-07-14 10:54:40.000000000 +0000
@@ -1,19 +1,6 @@
 package org.basex;
 
-import static org.basex.core.Text.*;
-import static org.junit.Assert.*;
-
-import java.io.*;
-import java.util.concurrent.*;
-
-import org.basex.api.client.*;
 import org.basex.core.*;
-import org.basex.core.users.*;
-import org.basex.io.*;
-import org.basex.io.out.*;
-import org.basex.util.*;
-import org.basex.util.list.*;
-import org.basex.util.options.*;
 import org.junit.*;
 
 /**
@@ -22,166 +9,20 @@
  * @author BaseX Team 2005-15, BSD License
  * @author Christian Gruen
  */
-public abstract class SandboxTest {
-  /** Database port. */
-  protected static final int DB_PORT = 9996;
-  /** Event port. */
-  protected static final int EVENT_PORT = 9997;
-
-  /** Default output stream. */
-  public static final PrintStream OUT = System.out;
-  /** Default error stream. */
-  public static final PrintStream ERR = System.err;
-  /** Null output stream. */
-  public static final PrintStream NULL = new PrintStream(new NullOutput());
-  /** Test name. */
-  protected static final String NAME = Util.className(SandboxTest.class);
-  /** Database context. */
-  protected static Context context;
-
+public abstract class SandboxTest extends Sandbox {
   /**
    * Creates the sandbox.
    */
   @BeforeClass
-  public static void initSandbox() {
-    final IOFile sb = sandbox();
-    sb.delete();
-    assertTrue("Sandbox could not be created.", sb.md());
-    context = newContext();
+  public static void initTests() {
+    initSandbox();
   }
 
   /**
    * Removes test databases and closes the database context.
    */
   @AfterClass
-  public static void closeContext() {
-    context.close();
-    assertTrue("Sandbox could not be deleted.", sandbox().delete());
-  }
-
-  /**
-   * Creates a new specified context.
-   * @return context
-   */
-  public static Context newContext() {
-    final IOFile sb = sandbox();
-    Options.setSystem(StaticOptions.DBPATH.name(), sb.path() + "/data");
-    Options.setSystem(StaticOptions.WEBPATH.name(), sb.path() + "/webapp");
-    Options.setSystem(StaticOptions.RESTXQPATH.name(), sb.path() + "/webapp");
-    Options.setSystem(StaticOptions.REPOPATH.name(), sb.path() + "/repo");
-    try {
-      return new Context();
-    } finally {
-      Options.setSystem(StaticOptions.DBPATH.name(), "");
-      Options.setSystem(StaticOptions.WEBPATH.name(), "");
-      Options.setSystem(StaticOptions.RESTXQPATH.name(), "");
-      Options.setSystem(StaticOptions.REPOPATH.name(), "");
-    }
-  }
-
-  /**
-   * Creates a new, sandboxed server instance.
-   * @param args additional arguments
-   * @return server instance
-   * @throws IOException I/O exception
-   */
-  public static BaseXServer createServer(final String... args) throws IOException {
-    try {
-      System.setOut(NULL);
-      final StringList sl = new StringList("-z", "-p" + DB_PORT, "-e" + EVENT_PORT, "-q");
-      for(final String arg : args) sl.add(arg);
-      final BaseXServer server = new BaseXServer(sl.finish());
-      server.context.soptions.set(StaticOptions.DBPATH, sandbox().path());
-      return server;
-    } finally {
-      System.setOut(OUT);
-    }
-  }
-
-  /**
-   * Stops a server instance.
-   * @param server server
-   * @throws IOException I/O exception
-   */
-  public static void stopServer(final BaseXServer server) throws IOException {
-    try {
-      System.setOut(NULL);
-      if(server != null) server.stop();
-    } finally {
-      System.setOut(OUT);
-    }
-  }
-
-  /**
-   * Creates a client instance.
-   * @param login optional login data
-   * @return client instance
-   * @throws IOException I/O exception
-   */
-  public static ClientSession createClient(final String... login) throws IOException {
-    final String user = login.length > 0 ? login[0] : UserText.ADMIN;
-    final String pass = login.length > 1 ? login[1] : UserText.ADMIN;
-    return new ClientSession(S_LOCALHOST, DB_PORT, user, pass);
-  }
-
-  /**
-   * Returns the sandbox database path.
-   * @return database path
-   */
-  public static IOFile sandbox() {
-    return new IOFile(Prop.TMP, NAME);
-  }
-
-  /**
-   * Normalizes newlines in a query result.
-   * @param result input string
-   * @return normalized string
-   */
-  public static String normNL(final Object result) {
-    return result.toString().replaceAll("(\r?\n|\r) *", "\n");
-  }
-
-  /** Client. */
-  public static final class Client extends Thread {
-    /** Start signal. */
-    private final CountDownLatch startSignal;
-    /** Stop signal. */
-    private final CountDownLatch stopSignal;
-    /** Client session. */
-    private final ClientSession session;
-    /** Command string. */
-    private final Command cmd;
-    /** Fail flag. */
-    public String error;
-
-    /**
-     * Client constructor.
-     * @param c command string to execute
-     * @param start start signal
-     * @param stop stop signal
-     * @throws IOException I/O exception while establishing the session
-     */
-    public Client(final Command c, final CountDownLatch start, final CountDownLatch stop)
-        throws IOException {
-
-      session = createClient();
-      cmd = c;
-      startSignal = start;
-      stopSignal = stop;
-      start();
-    }
-
-    @Override
-    public void run() {
-      try {
-        if(startSignal != null) startSignal.await();
-        session.execute(cmd);
-        session.close();
-      } catch(final Throwable ex) {
-        error = "\n" + cmd + '\n' + ex;
-      } finally {
-        if(stopSignal != null) stopSignal.countDown();
-      }
-    }
+  public static void finishTests() {
+    finishSandbox();
   }
 }
diff -Nru basex-8.1.1/CHANGELOG basex-8.2.3/CHANGELOG
--- basex-8.1.1/CHANGELOG	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/CHANGELOG	2015-07-14 10:54:40.000000000 +0000
@@ -1,3 +1,47 @@
+VERSION 8.2.3 (July 14, 2015) ------------------------------------------
+
+ Bug fixes (DBA, admin:write-log; namespaces)
+
+VERSION 8.2.2 (July 6, 2015) -------------------------------------------
+
+ Various bug fixes (all minor)
+
+VERSION 8.2.1 (June 9, 2015) -------------------------------------------
+
+ DBA
+ - code highlighting (thanks, James Ball!)
+ - new panel for up- and downloading files
+ - queries and files are now stored in a temporary directory
+
+ GENERAL
+ - various bug fixes
+
+VERSION 8.2 (May 21, 2015) ---------------------------------------------
+
+ XQUERY
+ - much faster sequence modification via finger trees
+ - improved compliance with XQuery 3.1
+
+ DBA
+ - open, save and delete queries
+ - better Tomcat support
+
+ STORAGE
+ - updatable index structures: reduced disk space consumption
+
+ XQUERY FUNCTIONS
+ - Standard Module: fn:json-to-xml, fn:xml-to-json
+ - Web Module: web:encode-url, web:decode-url
+ - File Module: file:is-absolute, file:resolve-path
+ - Admin Module: admin:delete-logs
+ - Database Module: db:output-cache
+
+ BUG FIXES
+ - locking, full-text requests, stemming
+
+ REMOVED FEATURES
+ - event handling (will be replaced by database triggers)
+
 VERSION 8.1.1 (April 16, 2015) -----------------------------------------
 
  Various bug fixes (all minor)
diff -Nru basex-8.1.1/debian/changelog basex-8.2.3/debian/changelog
--- basex-8.1.1/debian/changelog	2015-04-16 20:44:10.000000000 +0000
+++ basex-8.2.3/debian/changelog	2015-07-20 07:49:20.000000000 +0000
@@ -1,3 +1,55 @@
+basex (8.2.3-1) unstable; urgency=medium
+
+  * New upstream releases
+    VERSION 8.2.3 (July 14, 2015) ------------------------------------------
+    
+     Bug fixes (DBA, admin:write-log; namespaces)
+    
+    VERSION 8.2.2 (July 6, 2015) -------------------------------------------
+    
+     Various bug fixes (all minor)
+    
+    VERSION 8.2.1 (June 9, 2015) -------------------------------------------
+    
+     DBA
+     - code highlighting (thanks, James Ball!)
+     - new panel for up- and downloading files
+     - queries and files are now stored in a temporary directory
+    
+     GENERAL
+     - various bug fixes
+    
+    VERSION 8.2 (May 21, 2015) ---------------------------------------------
+    
+     XQUERY
+     - much faster sequence modification via finger trees
+     - improved compliance with XQuery 3.1
+    
+     DBA
+     - open, save and delete queries
+     - better Tomcat support
+    
+     STORAGE
+     - updatable index structures: reduced disk space consumption
+    
+     XQUERY FUNCTIONS
+     - Standard Module: fn:json-to-xml, fn:xml-to-json
+     - Web Module: web:encode-url, web:decode-url
+     - File Module: file:is-absolute, file:resolve-path
+     - Admin Module: admin:delete-logs
+     - Database Module: db:output-cache
+    
+     BUG FIXES
+     - locking, full-text requests, stemming
+    
+     REMOVED FEATURES
+     - event handling (will be replaced by database triggers)
+
+  * Packaging:
+    - Added jing as recommended package. Updated startup scripts accordingly.
+
+ -- Alexander Holupirek <alex@holupirek.de>  Fri, 17 Jul 2015 09:03:33 +0200
+
 basex (8.1.1-1) unstable; urgency=medium
 
   * New upstream release
diff -Nru basex-8.1.1/debian/control basex-8.2.3/debian/control
--- basex-8.1.1/debian/control	2015-03-20 14:07:39.000000000 +0000
+++ basex-8.2.3/debian/control	2015-07-17 09:54:01.000000000 +0000
@@ -11,9 +11,9 @@
 
 Package: basex
 Architecture: all
-Depends: ${misc:Depends}, ${maven:Depends}, java-wrappers, default-jre | java6-runtime
+Depends: ${misc:Depends}, ${maven:Depends}, java-wrappers, default-jre | java7-runtime
 Recommends: ${maven:OptionalDepends}
-Suggests: libtagsoup-java, libxml-commons-resolver1.1-java, libjline2-java
+Suggests: libtagsoup-java, libxml-commons-resolver1.1-java, libjline2-java, libjing-java
 Description: XML database and XPath/XQuery processor
  BaseX is a very fast and light-weight, yet powerful XML database and
  XPath/XQuery processor, including support for the latest W3C Full Text and
diff -Nru basex-8.1.1/debian/man/basex.1 basex-8.2.3/debian/man/basex.1
--- basex-8.1.1/debian/man/basex.1	2015-04-16 20:39:03.000000000 +0000
+++ basex-8.2.3/debian/man/basex.1	2015-07-20 07:46:43.000000000 +0000
@@ -1,12 +1,12 @@
-.\"Text automatically generated by txt2man
-.TH basex 1 "16 April 2015" "" "The XML Database"
+.\" Text automatically generated by txt2man
+.TH basex 1 "17 July 2015" "" "The XML Database"
 .SH NAME
 \fBbasex \fP- XML database system and XPath/XQuery processor (command line mode)
 \fB
 .SH SYNOPSIS
 .nf
 .fam C
-\fBbasex\fP [\fB-bcdioqrRsuvVwxXz\fP] [\fIinput\fP]
+\fBbasex\fP [\fB-bcdiIoqrRstuvVwxXz\fP] [\fIinput\fP]
 
 .fam T
 .fi
@@ -45,7 +45,7 @@
 .fam C
    $ basex 19+23
    42
-   $ basex -q "<answer>{ 23+19 }</answer>"
+   $ basex \-q "<answer>{ 23+19 }</answer>"
    <answer>42</answer>
 
 .fam T
@@ -237,7 +237,7 @@
 
    Alternative:
 
-   $ basex -q 'declare option db:parser "html"; doc("bad.html")' 
+   $ basex \-q 'declare option db:parser "html"; doc("bad.html")' 
    <html xmlns="http://www.w3.org/1999/xhtml">
      <body>
        <ul>
diff -Nru basex-8.1.1/debian/man/basex.1e basex-8.2.3/debian/man/basex.1e
--- basex-8.1.1/debian/man/basex.1e	2015-04-16 20:39:03.000000000 +0000
+++ basex-8.2.3/debian/man/basex.1e	2015-07-17 10:48:11.000000000 +0000
@@ -1,12 +1,12 @@
-.\"Text automatically generated by txt2man
-.TH basex 1 "16 April 2015" "" "The XML Database"
+.\" Text automatically generated by txt2man
+.TH basex 1 "17 July 2015" "" "The XML Database"
 .SH NAME
 \fBbasex \fP- XML database system and XPath/XQuery processor (command line mode)
 \fB
 .SH SYNOPSIS
 .nf
 .fam C
-\fBbasex\fP [\fB-bcdioqrRsuvVwxXz\fP] [\fIinput\fP]
+\fBbasex\fP [\fB-bcdiIoqrRstuvVwxXz\fP] [\fIinput\fP]
 
 .fam T
 .fi
diff -Nru basex-8.1.1/debian/man/basexclient.1 basex-8.2.3/debian/man/basexclient.1
--- basex-8.1.1/debian/man/basexclient.1	2015-04-16 20:39:03.000000000 +0000
+++ basex-8.2.3/debian/man/basexclient.1	2015-07-17 10:48:11.000000000 +0000
@@ -1,12 +1,12 @@
-.\"Text automatically generated by txt2man
-.TH basexclient 1 "16 April 2015" "" "The XML Database"
+.\" Text automatically generated by txt2man
+.TH basexclient 1 "17 July 2015" "" "The XML Database"
 .SH NAME
 \fBbasexclient \fP- XML database system and XPath/XQuery processor (client mode)
 \fB
 .SH SYNOPSIS
 .nf
 .fam C
-\fBbasexclient\fP [\fB-bcdinopPqrRsUvVwxz\fP] [\fIinput\fP]
+\fBbasexclient\fP [\fB-bcdiInopPqrRsUvVwxXz\fP] [\fIinput\fP]
 
 .fam T
 .fi
diff -Nru basex-8.1.1/debian/man/basexclient.txt basex-8.2.3/debian/man/basexclient.txt
--- basex-8.1.1/debian/man/basexclient.txt	2015-04-16 20:38:12.000000000 +0000
+++ basex-8.2.3/debian/man/basexclient.txt	2015-07-17 10:47:25.000000000 +0000
@@ -2,7 +2,7 @@
   basexclient - XML database system and XPath/XQuery processor (client mode)
 
 SYNOPSIS
-  basexclient [-bcdinopPqrRsUvVwxz] [input]
+  basexclient [-bcdiInopPqrRsUvVwxXz] [input]
 
 DESCRIPTION
   basexclient starts a basex(1) XML database client in order to connect to a
diff -Nru basex-8.1.1/debian/man/basexgui.1 basex-8.2.3/debian/man/basexgui.1
--- basex-8.1.1/debian/man/basexgui.1	2015-04-16 20:39:03.000000000 +0000
+++ basex-8.2.3/debian/man/basexgui.1	2015-07-17 10:48:11.000000000 +0000
@@ -1,5 +1,5 @@
-.\"Text automatically generated by txt2man
-.TH basexgui 1 "16 April 2015" "" "The XML Database"
+.\" Text automatically generated by txt2man
+.TH basexgui 1 "17 July 2015" "" "The XML Database"
 .SH NAME
 \fBbasexgui \fP- XML database system and XPath/XQuery processor (graphical mode)
 \fB
diff -Nru basex-8.1.1/debian/man/basexserver.1 basex-8.2.3/debian/man/basexserver.1
--- basex-8.1.1/debian/man/basexserver.1	2015-04-16 20:39:03.000000000 +0000
+++ basex-8.2.3/debian/man/basexserver.1	2015-07-17 10:48:11.000000000 +0000
@@ -1,12 +1,12 @@
-.\"Text automatically generated by txt2man
-.TH basexserver 1 "16 April 2015" "" "The XML Database"
+.\" Text automatically generated by txt2man
+.TH basexserver 1 "17 July 2015" "" "The XML Database"
 .SH NAME
 \fBbasexserver \fP- XML database system and XPath/XQuery processor (server mode)
 \fB
 .SH SYNOPSIS
 .nf
 .fam C
-\fBbasexserver\fP [\fB-cdeinpSz\fP] [\fIstop\fP]
+\fBbasexserver\fP [\fB-cdinpSz\fP] [\fIstop\fP]
 
 .fam T
 .fi
diff -Nru basex-8.1.1/debian/man/basexserver.txt basex-8.2.3/debian/man/basexserver.txt
--- basex-8.1.1/debian/man/basexserver.txt	2015-04-16 20:38:38.000000000 +0000
+++ basex-8.2.3/debian/man/basexserver.txt	2015-07-17 10:47:51.000000000 +0000
@@ -2,7 +2,7 @@
   basexserver - XML database system and XPath/XQuery processor (server mode)
 
 SYNOPSIS
-  basexserver [-cdeinpSz] [stop]
+  basexserver [-cdinpSz] [stop]
 
 DESCRIPTION
   basexserver starts the server mode of the native XML database system basex(1) on default port 1984.
diff -Nru basex-8.1.1/debian/man/basex.txt basex-8.2.3/debian/man/basex.txt
--- basex-8.1.1/debian/man/basex.txt	2015-04-16 20:36:31.000000000 +0000
+++ basex-8.2.3/debian/man/basex.txt	2015-07-17 10:46:59.000000000 +0000
@@ -2,7 +2,7 @@
   basex - XML database system and XPath/XQuery processor (command line mode)
 
 SYNOPSIS
-  basex [-bcdioqrRsuvVwxXz] [input]
+  basex [-bcdiIoqrRstuvVwxXz] [input]
 
 DESCRIPTION
   basex is a fast and powerful, yet light-weight and platform independent XML
diff -Nru basex-8.1.1/debian/maven.ignoreRules basex-8.2.3/debian/maven.ignoreRules
--- basex-8.1.1/debian/maven.ignoreRules	2015-04-16 20:42:51.000000000 +0000
+++ basex-8.2.3/debian/maven.ignoreRules	2015-07-20 10:03:33.000000000 +0000
@@ -1,5 +1,6 @@
 
 org.basex basex-api jar * * *
+com.thaiopensource jing * * * *
 jp.sourceforge.igo igo * * * *
 junit junit * * * *
 org.apache lucene-stemmers * * * *
diff -Nru basex-8.1.1/debian/scripts/basex basex-8.2.3/debian/scripts/basex
--- basex-8.1.1/debian/scripts/basex	2013-10-17 13:48:50.000000000 +0000
+++ basex-8.2.3/debian/scripts/basex	2015-07-17 09:53:15.000000000 +0000
@@ -1,19 +1,20 @@
 #!/bin/sh
 # Wrapper to start basex in command line mode.
 #
-# (c) 2011-13 Alexander Holupirek <alex@holupirek.de>, BSD
+# (c) 2011-15 Alexander Holupirek <alex@holupirek.de>, BSD
 #
 
 #DEBUG_WRAPPER=1
 
 . /usr/lib/java-wrappers/java-wrappers.sh
-find_java_runtime java6
+find_java_runtime java7
 find_jars /usr/share/java/basex.jar
-# Next jars are helpful (and as such recommended by the package),
+# Next jars are helpful (and therefore recommended by the package),
 # but they are not necessary at all to run basex. As such, there is no
 # need to print a warning message, if they are not found
 find_jars /usr/share/java/tagsoup.jar 2>/dev/null 
 find_jars /usr/share/java/jline.jar 2>/dev/null
 find_jars /usr/share/java/xml-resolver.jar 2>/dev/null 
+find_jars /usr/share/java/jing.jar 2>/dev/null
 
 run_java org.basex.BaseX "$@"
diff -Nru basex-8.1.1/debian/scripts/basexclient basex-8.2.3/debian/scripts/basexclient
--- basex-8.1.1/debian/scripts/basexclient	2013-10-17 13:48:08.000000000 +0000
+++ basex-8.2.3/debian/scripts/basexclient	2015-07-17 09:53:15.000000000 +0000
@@ -1,20 +1,20 @@
 #!/bin/sh
 # Wrapper to start basex database client.
 #
-# (c) 2011-13 Alexander Holupirek <alex@holupirek.de>, BSD
+# (c) 2011-15 Alexander Holupirek <alex@holupirek.de>, BSD
 #
 
 #DEBUG_WRAPPER=1 
 
 . /usr/lib/java-wrappers/java-wrappers.sh
-find_java_runtime java6
+find_java_runtime java7
 find_jars /usr/share/java/basex.jar
-# Next jars are helpful (and as such recommended by the package),
+# Next jars are helpful (and therefore recommended by the package),
 # but they are not necessary at all to run basex. As such, there is no
 # need to print a warning message, if they are not found
 find_jars /usr/share/java/tagsoup.jar 2>/dev/null 
 find_jars /usr/share/java/jline.jar 2>/dev/null
 find_jars /usr/share/java/xml-resolver.jar 2>/dev/null 
-
+find_jars /usr/share/java/jing.jar 2>/dev/null
 
 run_java org.basex.BaseXClient "$@"
diff -Nru basex-8.1.1/debian/scripts/basexgui basex-8.2.3/debian/scripts/basexgui
--- basex-8.1.1/debian/scripts/basexgui	2013-10-17 13:47:22.000000000 +0000
+++ basex-8.2.3/debian/scripts/basexgui	2015-07-17 09:53:15.000000000 +0000
@@ -1,19 +1,20 @@
 #!/bin/sh
 # Wrapper to start basex gui mode.
 #
-# (c) 2011-13 Alexander Holupirek <alex@holupirek.de>, BSD
+# (c) 2011-15 Alexander Holupirek <alex@holupirek.de>, BSD
 #
 
 #DEBUG_WRAPPER=1 
 
 . /usr/lib/java-wrappers/java-wrappers.sh
-find_java_runtime java6
+find_java_runtime java7
 find_jars /usr/share/java/basex.jar
-# Next jars are helpful (and as such recommended by the package),
+# Next jars are helpful (and therefore recommended by the package),
 # but they are not necessary at all to run basex. As such, there is no
 # need to print a warning message, if they are not found
 find_jars /usr/share/java/tagsoup.jar 2>/dev/null 
 find_jars /usr/share/java/jline.jar 2>/dev/null
 find_jars /usr/share/java/xml-resolver.jar 2>/dev/null 
+find_jars /usr/share/java/jing.jar 2>/dev/null
 
 run_java org.basex.BaseXGUI "$@"
diff -Nru basex-8.1.1/debian/scripts/basexserver basex-8.2.3/debian/scripts/basexserver
--- basex-8.1.1/debian/scripts/basexserver	2013-10-17 13:48:49.000000000 +0000
+++ basex-8.2.3/debian/scripts/basexserver	2015-07-17 09:53:15.000000000 +0000
@@ -1,19 +1,20 @@
 #!/bin/sh
 # Wrapper to start basex as database server.
 #
-# (c) 2011-13 Alexander Holupirek <alex@holupirek.de>, BSD
+# (c) 2011-15 Alexander Holupirek <alex@holupirek.de>, BSD
 #
 
 #DEBUG_WRAPPER=1 
 
 . /usr/lib/java-wrappers/java-wrappers.sh
-find_java_runtime java6
+find_java_runtime java7
 find_jars /usr/share/java/basex.jar
-# Next jars are helpful (and as such recommended by the package),
+# Next jars are helpful (and therefore recommended by the package),
 # but they are not necessary at all to run basex. As such, there is no
 # need to print a warning message, if they are not found
 find_jars /usr/share/java/tagsoup.jar 2>/dev/null 
 find_jars /usr/share/java/jline.jar 2>/dev/null
 find_jars /usr/share/java/xml-resolver.jar 2>/dev/null 
+find_jars /usr/share/java/jing.jar 2>/dev/null
 
 run_java org.basex.BaseXServer "$@"
diff -Nru basex-8.1.1/pom.xml basex-8.2.3/pom.xml
--- basex-8.1.1/pom.xml	2015-04-16 13:52:47.000000000 +0000
+++ basex-8.2.3/pom.xml	2015-07-14 10:54:40.000000000 +0000
@@ -5,7 +5,7 @@
   <!-- Artifact information -->
   <groupId>org.basex</groupId>
   <artifactId>basex-parent</artifactId>
-	<version>8.1.1</version>
+  <version>8.2.3</version>
   <packaging>pom</packaging>
 
   <modules>
@@ -65,6 +65,29 @@
         <optional>true</optional>
       </dependency>
       <dependency>
+        <groupId>com.thaiopensource</groupId>
+        <artifactId>jing</artifactId>
+        <version>20091111</version>
+        <exclusions>
+          <exclusion>
+            <groupId>xerces</groupId>
+            <artifactId>xercesImpl</artifactId>
+          </exclusion>
+          <exclusion>
+            <groupId>xml-apis</groupId>
+            <artifactId>xml-apis</artifactId>
+          </exclusion>
+          <exclusion>
+            <groupId>net.sf.saxon</groupId>
+            <artifactId>saxon</artifactId>
+          </exclusion>
+          <exclusion>
+            <groupId>isorelax</groupId>
+            <artifactId>isorelax</artifactId>
+          </exclusion>
+        </exclusions>
+      </dependency>
+      <dependency>
         <groupId>net.xqj</groupId>
         <artifactId>basex-xqj</artifactId>
         <version>1.4.0</version>