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Negative Lookahead Assertion Problemby Limbic~Region (Chancellor) |
on Jul 18, 2005 at 23:05 UTC ( [id://475910]=perlquestion: print w/replies, xml ) | Need Help?? |
Limbic~Region has asked for the wisdom of the Perl Monks concerning the following question:
All,
In #perl tonight on IRC, someone asked how to match 'Foo::Bar' but not match 'Foo::Bar\s*(' Not having very strong fu, I looked up perlre and found a negative lookahead assertion I was told that it was inadequate because it didn't work in the general case (where Foo::Bar is getting replaced by \w+::\w+). I found that Foo could change to \w+ without a problem but that Bar couldn't. I believe this has to do with the 0-width part about assertions but why, in plain english, doesn't the following work? And - how would I properly answer this question in the future? While I have never tried to claim I had more regex knowledge then I have - I find not knowing the answer to this a bit embarrasing after using the language for 3 years. Cheers - L~R Update:Thanks all! I really should spend some time with The Owl and TFM.
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