does anyone know if backrefs are supposed to work within the {} quantifier, or not?

Good question.

My guess would be that they're not supposed to work -- text matched in a backreference is matched textually, without metacharacters. So doing /^(.)\1$/ won't match a wildcard as a second character if the first is a literal ".", and won't match one or more "+" if the first character is a literal "+".

Keeping to that pattern, it makes sense that if a backreference appears between {}, what's parsed is a literal "{", the backreference, and a literal "}".

It would obviously complicate regexen something fierce if the possibility of recompiling the regex based on backreferences had to be handled in the general case, and not just in the ??{} case.


Mike

In reply to Re^3: Backref in a regex quantifier by RMGir
in thread Backref in a regex quantifier by Anonymous Monk

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