From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.help Subject: Re: empty-line-p Date: Sun, 01 Apr 2007 16:57:48 -0400 Message-ID: References: NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: sea.gmane.org 1175463569 25345 80.91.229.12 (1 Apr 2007 21:39:29 GMT) X-Complaints-To: usenet@sea.gmane.org NNTP-Posting-Date: Sun, 1 Apr 2007 21:39:29 +0000 (UTC) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Sun Apr 01 23:39:23 2007 Return-path: Envelope-to: geh-help-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by lo.gmane.org with esmtp (Exim 4.50) id 1HY7lf-0006vl-Mm for geh-help-gnu-emacs@m.gmane.org; Sun, 01 Apr 2007 23:39:19 +0200 Original-Received: from localhost ([127.0.0.1] helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1HY7oc-0003aA-Tl for geh-help-gnu-emacs@m.gmane.org; Sun, 01 Apr 2007 17:42:22 -0400 Original-Path: shelby.stanford.edu!headwall.stanford.edu!newsfeed.news2me.com!nx01.iad01.newshosting.com!newshosting.com!216.196.98.140.MISMATCH!border1.nntp.dca.giganews.com!nntp.giganews.com!local01.nntp.dca.giganews.com!nntp.umontreal.ca!news.umontreal.ca.POSTED!not-for-mail Original-NNTP-Posting-Date: Sun, 01 Apr 2007 15:57:48 -0500 Original-Newsgroups: gnu.emacs.help User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.0.96 (gnu/linux) Cancel-Lock: sha1:5M02aIWGykCzU5dNo8tGtKxR/3A= Original-Lines: 13 Original-NNTP-Posting-Host: 132.204.27.213 Original-X-Trace: sv3-6EOgeo7PCq7r28Bp3V9ZEPeV1DSJY2O7AEBbPirHOMDxg6M1VP/tmD78R4Oo+8Vs72tz0T6WTPAvcdr!otsjXSjRb4t5pbjMG2CArlGExkGsqYd1qlAOiphPBndnnuN5ej//AykzKCfGlwcrEiUtnyH+3BHQ!LaHRm2NOsLJ857moDw== Original-X-Complaints-To: abuse@umontreal.ca X-DMCA-Complaints-To: abuse@umontreal.ca X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.3.34 Original-Xref: shelby.stanford.edu gnu.emacs.help:146745 X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.help:42349 Archived-At: > And to avoid some painful bug hunting (happened to me with nearly > the same code) wrap it in a `save-match-data'. I'd advise against such a change. The cost of save-match-data is fairly high, so instead of using it everywhere, the coding convention in elisp is to be careful that between a regexp-match and the use of match-beginning (and friends) there should be almost no other operation since most operations (other than the few known safe ones) may trash the match-data. Stefan