libghc-snap-core-dev 1.0.4.0-1build1 (amd64 binary) in ubuntu focal

 Snap is a simple and fast web development framework and server written in
 Haskell. For more information or to download the latest version, you can
 visit the Snap project website at <http://snapframework.com/>.
 .
 This library contains the core definitions and types for the Snap framework,
 including:
 .
 1. Primitive types and functions for HTTP (requests, responses, cookies,
 post/query parameters, etc)
 .
 2. Type aliases and helper functions for Iteratee I/O
 .
 3. A monad for programming web handlers called \"Snap\", inspired by
 happstack's (<http://happstack.com/index.html>), which allows:
 .
 o Stateful access to the HTTP request and response objects
 .
 o Monadic failure (i.e. MonadPlus/Alternative instances) for declining
 to handle requests and chaining handlers together
 .
 o Early termination of the computation if you know early what you want
 to return and want to prevent further monadic processing
 .
 This package contains the normal library files.