I've got a working grammar that will parse, say A a1 a2 a3 B b1 b2
into structures. A and B don't overlap so I know that any sequence beginning with A must have a1, a2, and a3. Now I'm interested in finding out how much of the A rule can be matched, for tab-completion (so I can tell if a1, a2, or a3 should be completed). I'm using Term::ReadLine::Gnu but that's not too important. Basically I want, given "A a1", to say "oh you want all the possible values for a2 and a1 is already given." I'm currently doing this by making a1..3 optional and then assembling them back in order, but was wondering if there's a better way to fail the match but tell me how far the parser got before it failed. Thanks Ted
