> Lähettäjä: "Phrogz" <gavin@refinery.com>
> Aihe: Regexp help - Negative lookahead before across word boundaries
>
> Given a string like this:
> "this.position.x = foo.bar.whee * jim.jam - yow / this.jorgle"
>
> I want to match all the global identifiers which are not 'this', and I
> 'need' to do so without consuming any other characters.
>
> This regexp:
> /[^.]\b(?!this)[a-zA-Z_]\w*\b/
> works, but it consumes the preceding character.
>
> I thought this regexp would work:
> /(?!\.)\b(?!this)[a-zA-Z_]\w*\b/i
> but now I realize why it doesn't. (Because the position after the
> period satifies the negative lookahead and the word boundary.)
I'm assuming 'global identifier' means any sort of a variable label
instead of a '$global' identifier (correct if I'm wrong)? You could
do two things; first, to circumvent the whole negative lookahead, you could just do:
(?:(?:this)|([a-zA-Z_])
And check for a $1 match. If you want to use the negative, I think you
have to consume it somehow:
(?!this)([a-zA-Z_]+?)
Should first ensure that 'this' isn't present, then backtrack and
move to the next match segment (which here matches any of those
specified characters) *from the same area*. You should be able to
vary that basic idea to fit your need. Apparently Oniguruma will
include a n-w look-BACK, which'll be a help :)
> Help?
E