From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.bugs Subject: bug#13260: 24.3.50; save match data for core functions like `delete-char' and `delete-backward-char'? Date: Mon, 24 Dec 2012 00:09:55 -0500 Message-ID: References: <87zk143ihe.fsf@bzg.ath.cx> <87bodkbu2k.fsf@bzg.ath.cx> <878v8outs8.fsf@bzg.ath.cx> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1356325838 1487 80.91.229.3 (24 Dec 2012 05:10:38 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Mon, 24 Dec 2012 05:10:38 +0000 (UTC) Cc: 13260@debbugs.gnu.org To: Bastien Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Mon Dec 24 06:10:52 2012 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1Tn0JP-0000Nh-TO for geb-bug-gnu-emacs@m.gmane.org; Mon, 24 Dec 2012 06:10:52 +0100 Original-Received: from localhost ([::1]:52746 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Tn0JB-0000Es-MH for geb-bug-gnu-emacs@m.gmane.org; Mon, 24 Dec 2012 00:10:37 -0500 Original-Received: from eggs.gnu.org ([208.118.235.92]:40473) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Tn0J8-0000EZ-R5 for bug-gnu-emacs@gnu.org; Mon, 24 Dec 2012 00:10:35 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Tn0J7-0005JE-Mx for bug-gnu-emacs@gnu.org; Mon, 24 Dec 2012 00:10:34 -0500 Original-Received: from debbugs.gnu.org ([140.186.70.43]:47121) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Tn0J7-0005J9-K0 for bug-gnu-emacs@gnu.org; Mon, 24 Dec 2012 00:10:33 -0500 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.72) (envelope-from ) id 1Tn0JZ-0005Yp-SZ for bug-gnu-emacs@gnu.org; Mon, 24 Dec 2012 00:11:01 -0500 X-Loop: help-debbugs@gnu.org Resent-From: Stefan Monnier Original-Sender: debbugs-submit-bounces@debbugs.gnu.org Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Mon, 24 Dec 2012 05:11:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 13260 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: wontfix Original-Received: via spool by 13260-submit@debbugs.gnu.org id=B13260.135632582821328 (code B ref 13260); Mon, 24 Dec 2012 05:11:01 +0000 Original-Received: (at 13260) by debbugs.gnu.org; 24 Dec 2012 05:10:28 +0000 Original-Received: from localhost ([127.0.0.1]:57372 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.72) (envelope-from ) id 1Tn0J2-0005Xx-AV for submit@debbugs.gnu.org; Mon, 24 Dec 2012 00:10:28 -0500 Original-Received: from ironport2-out.teksavvy.com ([206.248.154.182]:47085) by debbugs.gnu.org with esmtp (Exim 4.72) (envelope-from ) id 1Tn0Iz-0005Xp-Mi for 13260@debbugs.gnu.org; Mon, 24 Dec 2012 00:10:26 -0500 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: Ai0FAG6Zu09FxLDj/2dsb2JhbABEsEiDSYEIghUBAQQBViMFCws0BwsUGA0kiBwFugmQRAOIQppxgViDBw X-IronPort-AV: E=Sophos;i="4.75,637,1330923600"; d="scan'208";a="210625616" Original-Received: from 69-196-176-227.dsl.teksavvy.com (HELO fmsmemgm.homelinux.net) ([69.196.176.227]) by ironport2-out.teksavvy.com with ESMTP/TLS/ADH-AES256-SHA; 24 Dec 2012 00:09:56 -0500 Original-Received: by fmsmemgm.homelinux.net (Postfix, from userid 20848) id 1FFA1AE071; Mon, 24 Dec 2012 00:09:55 -0500 (EST) In-Reply-To: <878v8outs8.fsf@bzg.ath.cx> (Bastien's message of "Mon, 24 Dec 2012 02:24:07 +0100") User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3.50 (gnu/linux) X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.13 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6.x X-Received-From: 140.186.70.43 X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Original-Sender: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.bugs:68979 Archived-At: > I'm fine with a rule like "anything that modifies the buffer should > be assumed to destroy the match data" -- given your explanation above. > But I'm not convinced this should apply to all other functions. Basically, if you need the match-data, you should get it right after the match itself. So save-match-data is something to use between the match and the match-data extraction (unless this code is trivial, as is usually the case), rather than around functions that might potentially appear occasionally somewhere between a match and a match-data extraction. I know these requests will keep coming until the byte-compiler is enhanced to flag places where a save-match-data is potentially missing, or maybe until we replace the "string-match followed by match-beginning/end" with a "match and then bind subgroups to provided vars". Stefan