On 2010-05-27 11:57, Panciz wrote: > It's trivial in simple grammars like > > NonTerm1 <-- NonTerm3 / NonTerm2 > NonTerm2 <-- NonTerm3 "sym"
In this case, the "/ NonTerm2" alternative in NonTerm1 is useless. If NonTerm3 "sym" would match, then NonTerm3 will match, and so the second branch of the ordered choice in NonTerm1 will never be tried in any case in which it could succeed, right? > In order to compare NonTerm3 with NonTerm2 I need to check for their > definition > and then recursevly check in their definition until I found > out if NonTerm2 prevents or not the choice NonTerm3. This sounds to me like something other than PEG ordered choice, (and undecidable) but maybe I'm not understanding what it is you are after. -- Michaeljohn Clement http://inimino.org/~inimino/blog/ _______________________________________________ PEG mailing list PEG@lists.csail.mit.edu https://lists.csail.mit.edu/mailman/listinfo/peg
