From: Stefan Monnier <monnier@iro.umontreal.ca>
Subject: Re: Help needed with regexps
Date: Fri, 13 Feb 2004 19:37:32 GMT [thread overview]
Message-ID: <jwvwu6qrcvv.fsf-monnier+gnu.emacs.help@asado.iro.umontreal.ca> (raw)
In-Reply-To: pan.2004.02.13.19.17.40.790445@dzr-web.com
> :front "<style\\s-+\\(\\s-*.*\\s-+\\)*.*css\"?\\(\\s-*.*\\s-*\\)*\\s-*>"
Regexps like A*.*B* are asking for trouble because there is an exponential
numberof ways to match them and the regexp-engine uses backtracking.
So it will get stuck trying them all, potentially for hours or even years.
To you it just looks like "it's stuck".
Stefan
next prev parent reply other threads:[~2004-02-13 19:37 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-02-13 19:17 Help needed with regexps D. D. Brierton
2004-02-13 19:21 ` D. D. Brierton
2004-02-13 19:37 ` Stefan Monnier [this message]
2004-02-13 19:57 ` D. D. Brierton
2004-02-13 20:16 ` D. D. Brierton
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