After theDamian took a look at my spew program, he mentioned that it'd be nice if Parse::RecDescent could automatically randomly walk a grammar instead of just parse one, and seemed to think that there was enough meta inforamation in the internal grammar tree to do that.

If that's the way he felt about P::RD, I'm sure perl6 re-grammars are powerful enough as well, since a lot of the perl6 re-grammar stuff is based on P::RD ideas.

-- Randal L. Schwartz, Perl hacker