From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.ciao.gmane.io!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: :alnum: broken? Date: Fri, 28 Feb 2020 15:11:29 +0200 Message-ID: <83v9nqg8la.fsf@gnu.org> References: <86wo8flqct.fsf@stephe-leake.org> <86sgj3ljf0.fsf@stephe-leake.org> <5fecc0e1-1ee2-5a89-9297-b0b9aa4a8e9c@cs.ucla.edu> <03A37C4B-9FE8-4A25-9851-79BC8265455E@acm.org> <142e845d-eba3-5975-fa63-4c1b14ed4600@cs.ucla.edu> <3A14F30E-60EF-4C99-AC1A-9A1B2539169B@acm.org> <837e07gmka.fsf@gnu.org> <1c654ac9-10a2-4e5d-f77c-3b78bb580ffc@cs.ucla.edu> Injection-Info: ciao.gmane.io; posting-host="ciao.gmane.io:159.69.161.202"; logging-data="95464"; mail-complaints-to="usenet@ciao.gmane.io" Cc: mattiase@acm.org, cpitclaudel@gmail.com, emacs-devel@gnu.org To: Paul Eggert Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Fri Feb 28 14:12:12 2020 Return-path: Envelope-to: ged-emacs-devel@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1j7fR5-000OiZ-Iw for ged-emacs-devel@m.gmane-mx.org; Fri, 28 Feb 2020 14:12:11 +0100 Original-Received: from localhost ([::1]:46942 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j7fR4-0007wV-LP for ged-emacs-devel@m.gmane-mx.org; Fri, 28 Feb 2020 08:12:10 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:52833) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j7fQd-0007UN-MU for emacs-devel@gnu.org; Fri, 28 Feb 2020 08:11:44 -0500 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:37797) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1j7fQd-0000Kb-EE; Fri, 28 Feb 2020 08:11:43 -0500 Original-Received: from [176.228.60.248] (port=4675 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1j7fQc-0006pD-Us; Fri, 28 Feb 2020 08:11:43 -0500 In-reply-to: <1c654ac9-10a2-4e5d-f77c-3b78bb580ffc@cs.ucla.edu> (message from Paul Eggert on Fri, 28 Feb 2020 00:48:32 -0800) 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: 2.1.23 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-mx.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.io gmane.emacs.devel:245103 Archived-At: > Cc: emacs-devel@gnu.org, cpitclaudel@gmail.com > From: Paul Eggert > Date: Fri, 28 Feb 2020 00:48:32 -0800 > > On 2/28/20 12:09 AM, Eli Zaretskii wrote: > > I don't believe it is right for us to reject questionable but > > valid code. > > That begs the question. The code is valid only if we continue to insist that it > be valid, despite the clear drawbacks of doing so. I think it's valid due to regexp specification. > Instead, we can easily change the definition of Emacs regular > expressions so that the code is invalid. Since such code is > invariably a mistake, it's a win to make such a change. That's what > GNU grep has done for many years, and it works. So what is your question? > > I can even agree to reject this at > > run time under a non-default value of some special variable > > That would be better than nothing, but it's not very good since most people > won't know about the variable and thus will continue to suffer from these > errors. Better would be to make the default reject these buggy regexps, which is > what GNU grep does (it accepts the buggy regexps only if POSIXLY_CORRECT is set). We disagree (as has been established already).