From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: Scan of regexps in Emacs (March 17) Date: Wed, 03 Apr 2019 07:52:04 +0300 Message-ID: <83v9zvelmz.fsf@gnu.org> References: <5363970c-3207-1bb4-8b30-74a7d12277cc@cs.ucla.edu> <05269D79-B016-4FCB-94B8-068BF7D1C2D2@acm.org> <3974269b-6cad-0744-bd1f-66c067f94192@cs.ucla.edu> <4b1164c4-e302-ce41-07c3-145d31a97b4c@cs.ucla.edu> <21CCFA3D-B391-44E1-9ED5-1D37009F1988@acm.org> <09AE372B-3A30-4596-8C4E-B9F4CBF6E348@acm.org> <692fe297-1c72-0cda-8765-c119fd0b5ef6@cs.ucla.edu> Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="185845"; mail-complaints-to="usenet@blaine.gmane.org" Cc: mattiase@acm.org, monnier@iro.umontreal.ca, emacs-devel@gnu.org To: Paul Eggert Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Wed Apr 03 06:52:30 2019 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([209.51.188.17]) by blaine.gmane.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:256) (Exim 4.89) (envelope-from ) id 1hBXt0-000mGR-HQ for ged-emacs-devel@m.gmane.org; Wed, 03 Apr 2019 06:52:30 +0200 Original-Received: from localhost ([127.0.0.1]:42703 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hBXsz-0006Qy-D9 for ged-emacs-devel@m.gmane.org; Wed, 03 Apr 2019 00:52:29 -0400 Original-Received: from eggs.gnu.org ([209.51.188.92]:59442) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hBXsO-0006Ql-04 for emacs-devel@gnu.org; Wed, 03 Apr 2019 00:51:52 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:47778) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hBXsM-0006FL-Uk; Wed, 03 Apr 2019 00:51:51 -0400 Original-Received: from [176.228.60.248] (port=1197 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1hBXsM-0001X2-8o; Wed, 03 Apr 2019 00:51:50 -0400 In-reply-to: <692fe297-1c72-0cda-8765-c119fd0b5ef6@cs.ucla.edu> (message from Paul Eggert on Tue, 2 Apr 2019 15:08:43 -0700) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.org gmane.emacs.devel:234912 Archived-At: > From: Paul Eggert > Date: Tue, 2 Apr 2019 15:08:43 -0700 > Cc: Stefan Monnier , emacs-devel@gnu.org > > > (Do we have any latitude at all for changing even obscure corners of > > regexp syntax and semantics today?) > > I would say so, certainly for the raw 8-bit-bytes in ranges stuff (where > nobody knows what they mean or even should mean), and possibly even for > some of the other rarely-used and questionable uses. Beware: Emacs sometimes does use regexps when dealing with unibyte buffers and strings, where these ranges could be significant. So I'd suggest a careful audit of such places, to see whether raw bytes could be an issue, because the resulting breakage could be subtle and not become apparent until much later.