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
