libparse-recdescent-perl

Parse::RecDescent incrementally generates top-down recursive-descent text parsers from simple yacc-like grammar specifications. It provides: * Regular expressions or literal strings as terminals (tokens) * Multiple (non-contiguous) productions for any rule * Repeated and optional subrules within productions * Full access to Perl within actions specified as part of the grammar * Simple automated error reporting during parser generation and parsing * The ability to commit to, uncommit to, or reject particular productions during a parse * The ability to pass data up and down the parse tree ("down" via subrule argument lists, "up" via subrule return values) * Incremental extension of the parsing grammar (even during a parse) * Precompilation of parser objects * User-definable reduce-reduce conflict resolution via "scoring" of matching productions