in reply to Re: \g{-2} for inside (?{ ... })
in thread \g{-2} for inside (?{ ... })

Playing with regexp as parsers. See An adventure with 5.10 regular expressions.

The series of ( . ) represent a series arbitrarily complex grammar rules. I need to know what each rule matched.

Update: As I write this, it strikes me that what I want is not necessarily what those rules matched, so my question is moot.