unofficial mirror of help-gnu-emacs@gnu.org
 help / color / mirror / Atom feed
From: "D. D. Brierton" <darren@dzr-web.com>
Subject: Re: Help needed with regexps
Date: Fri, 13 Feb 2004 19:57:20 +0000	[thread overview]
Message-ID: <pan.2004.02.13.19.57.20.442717@dzr-web.com> (raw)
In-Reply-To: jwvwu6qrcvv.fsf-monnier+gnu.emacs.help@asado.iro.umontreal.ca

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            darren@dzr-web.com           www.dzr-web.com
       Trying is the first step towards failure (Homer Simpson)
======================================================================

  reply	other threads:[~2004-02-13 19:57 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
2004-02-13 19:57   ` D. D. Brierton [this message]
2004-02-13 20:16 ` D. D. Brierton

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

  List information: https://www.gnu.org/software/emacs/

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=pan.2004.02.13.19.57.20.442717@dzr-web.com \
    --to=darren@dzr-web.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).