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Re: Look-Arounds in Regexes are Hard (Common Use of a Negative Lookahead)by ikegami (Patriarch) |
on Jul 24, 2009 at 08:42 UTC ( [id://782882]=note: print w/replies, xml ) | Need Help?? |
I view
as the equivalent of
except it can prevent the match of entire regexps instead of a choice of characters. I call it the common use of a negative lookahead. If you're using a negative lookahead, that construct will probably satisfy your needs. Keep in mind that both expressions can successfully match 0 characters if not properly anchored. I think it would be nice if /(?^$re)/ could be added as a shortcut to /(?:(?!$re)(?s:.)*/. It would be more readable, and it would help prevent the common misuse of negative lookahead (/(?!$re.*)/). Update: Formatting.
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