Description:

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, optional and alternate subrules within productions,
- Late-bound (run-time dispatched) subrules,
- 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,
- 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.