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Re: Help needed with regexps


From: D. D. Brierton
Subject: Re: Help needed with regexps
Date: Fri, 13 Feb 2004 19:57:20 +0000
User-agent: Pan/0.14.2 (This is not a psychotic episode. It's a cleansing moment of clarity.)

On Fri, 13 Feb 2004 19:37:32 +0000, Stefan Monnier wrote:

>>              :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".

Ah of course. I'm such a nincompoop sometimes. Removing the many .*s with
more specific expressions has solved the emacs tailspin problem. Thanks!

Best, Darren

-- 
======================================================================
D. D. Brierton            address@hidden           www.dzr-web.com
       Trying is the first step towards failure (Homer Simpson)
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