in reply to
Backtracking through the regex world
Wow - what a cool use of local variables in regex code
expressions! And it shows, IMO by far the best way to
create complex regexes: machine generate them a bit at
a time for good comprehension.
This sort of approach to backtracking fits naturally into
the perl6 regex overhaul. Although ease of parsing complex
grammars will be the most obvious benefit of perl6 rules,
I think associated temp variables synchronized with backtracking
will provide a powerful tool for algorithms such as this.