greg is a re-entrant peg/leg, with some bug fixes. <http://piumarta.com/software/peg/> the most comprehensive example of greg usage is in nagaqueen, an ooc grammar, used in rock, an ooc compiler written in ooc. <http://github.com/nddrylliog/nagaqueen> <http://github.com/nddrylliog/rock> peg/leg is copyright (c) 2007 by Ian Piumarta released under an MIT license. as is greg.