RegEx Parser written in Prolog

Question

I\'ve been banging my head against the wall on this homework problem for a few hours now. We have to parse a regular expression with Prolog. For the most part, the predicat

Answer 1

I don't have access to SWI Prolog right now, but here is a guess:

Try changing

re_match(star(Rx), List) :- append(List1, List2, List),
                            re_match(Rx, List1),
                            re_match(star(Rx), List2).

to

re_match(star(Rx), List) :- append([H|List1], List2, List),
                            re_match(Rx, [H|List1]),
                            re_match(star(Rx), List2).

to force re_match to "eat something" when it iterates on the star construct.