From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Kevin Rodgers Newsgroups: gmane.emacs.help Subject: Re: `compare-strings' style question Date: Thu, 19 Nov 2009 20:08:59 -0700 Message-ID: References: <20091119105024.GA6950@tomas> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Trace: ger.gmane.org 1258686591 799 80.91.229.12 (20 Nov 2009 03:09:51 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Fri, 20 Nov 2009 03:09:51 +0000 (UTC) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Fri Nov 20 04:09:46 2009 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 1NBJsW-0005As-RK for geh-help-gnu-emacs@m.gmane.org; Fri, 20 Nov 2009 04:09:45 +0100 Original-Received: from localhost ([127.0.0.1]:52119 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NBJsW-0007Y9-6l for geh-help-gnu-emacs@m.gmane.org; Thu, 19 Nov 2009 22:09:44 -0500 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NBJsB-0007Xw-Ip for help-gnu-emacs@gnu.org; Thu, 19 Nov 2009 22:09:23 -0500 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1NBJs7-0007XT-3e for help-gnu-emacs@gnu.org; Thu, 19 Nov 2009 22:09:23 -0500 Original-Received: from [199.232.76.173] (port=46725 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NBJs6-0007XP-T6 for help-gnu-emacs@gnu.org; Thu, 19 Nov 2009 22:09:18 -0500 Original-Received: from lo.gmane.org ([80.91.229.12]:38127) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1NBJs6-00019Z-Gt for help-gnu-emacs@gnu.org; Thu, 19 Nov 2009 22:09:18 -0500 Original-Received: from list by lo.gmane.org with local (Exim 4.50) id 1NBJs4-00054c-E4 for help-gnu-emacs@gnu.org; Fri, 20 Nov 2009 04:09:16 +0100 Original-Received: from c-71-237-24-138.hsd1.co.comcast.net ([71.237.24.138]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Fri, 20 Nov 2009 04:09:16 +0100 Original-Received: from kevin.d.rodgers by c-71-237-24-138.hsd1.co.comcast.net with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Fri, 20 Nov 2009 04:09:16 +0100 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 28 Original-X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: c-71-237-24-138.hsd1.co.comcast.net User-Agent: Thunderbird 2.0.0.23 (Macintosh/20090812) In-Reply-To: <20091119105024.GA6950@tomas> X-detected-operating-system: by monty-python.gnu.org: GNU/Linux 2.6 (newer, 3) 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:69954 Archived-At: tomas@tuxteam.de wrote: > In Elisp, I'm trying to test whether a string is a prefix of another. > Poking around the documentation, I stumbled upon `compare-strings', > which seems to do the job fairly well. The interface is a bit weird > (at least as seen from Lisp) It feels more like C's strcmp. > > It returns t on exact match, and some numbers on mismatch. I understand > that the result might be useful in some cases (it tells one by how many > chars we miss a match), but then I can't just do > > (when (compare-strings foo 0 5 bar 0 5) > ...) > > but must do > > > (when (eq (compare-strings foo 0 5 bar 0 5) t) > ...) > > which looks rather funny. My question: are there better idioms? Am I > barking up the wrong function? (when (string-match (concat "^" (regexp-quote foo)) bar) ...) -- Kevin Rodgers Denver, Colorado, USA