mike mulligan replied to Peter Heslin: :> Simply put, I want variable-length lookbehind. : :The RFC seems to say you want this so that you can optimize the operation of :the regex execution. I've been looking at the existing fixed-length :look-behind and see that it does not seem to operate the way you may have :assumed. : :In particular, it is greedy in the sense of the forward matching "*" or "+" :constructs. [...] :$ perl "-Dr" -e "print qq($&\n) if qq(mxnxxxxoxxx) =~ /(?<=[aeiou])x*/" [snip] This is nothing to do with greediness and everything to do with left-to-rightness. The regexp engine does not look for x* except in those positions where the lookbehind has already matched. Hugo
- Re: RFC 72 (v2) The regexp engine should go backward as... mike mulligan
- Re: RFC 72 (v1) The regexp engine should go backward as... Mark-Jason Dominus
- Re: RFC 72 (v1) The regexp engine should go backwa... mike mulligan
- Re: RFC 72 (v1) The regexp engine should go ba... Mark-Jason Dominus
- Re: RFC 72 (v1) The regexp engine should g... Tom Christiansen
- Re: RFC 72 (v1) The regexp engine should go backwa... Peter Heslin
- Re: RFC 72 (v3) Variable-length lookbehind: th... mike mulligan
- Re: RFC 72 (v1) The regexp engine should go ba... Mark-Jason Dominus
- Re: RFC 72 (v1) The regexp engine should go ba... Mark-Jason Dominus
- Re: RFC 72 (v3) Variable-length lookbehind: th... Hugo
- Re: RFC 72 (v3) Variable-length lookbehind... Peter Heslin
- Re: RFC 72 (v3) Variable-length lookbehind... Robert Mathews
- Re: RFC 72 (v3) Variable-length lookbehind... Hugo