fast perl module for parsing the output of NCBI BLAST programs

 The Zerg library contains a C/flex lexical scanner for BLAST reports
 and a set of supporting functions. It is centered on a "get_token"
 function that scans the input for specified lexical elements and, when
 one is found, returns its code and value to the user.
 .
 It is intended to be fast: for that the authors used flex, which provides
 simple regular expression matching and input buffering in the
 generated C scanner. And it is intended to be simple in the sense of
 providing just a lexical scanner, with no features whose support could
 slow down its main function.