From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: =?utf-8?Q?Mattias_Engdeg=C3=A5rd?= Newsgroups: gmane.emacs.devel Subject: Re: More re odditie [Was: regular expressions that match nothing] Date: Thu, 16 May 2019 11:29:24 +0200 Message-ID: References: <7a6b23f52418b093a4cf7a6db4306cf425533249.camel@acm.org> <87a7fnzd3u.fsf@web.de> <128EBFB8-78FF-47C3-8F28-C1EF91BFC4BB@acm.org> <84fcfdce-39d7-1ebb-c0c7-98aa05854646@lsv.fr> Mime-Version: 1.0 (Mac OS X Mail 12.4 \(3445.104.8\)) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="135381"; mail-complaints-to="usenet@blaine.gmane.org" Cc: Michael Heerdegen , Stefan Monnier , emacs-devel@gnu.org To: phs@lsv.fr Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Thu May 16 14:04:52 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 1hRF7z-000Z4w-9w for ged-emacs-devel@m.gmane.org; Thu, 16 May 2019 14:04:51 +0200 Original-Received: from localhost ([127.0.0.1]:53204 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hRF7y-0003LV-Co for ged-emacs-devel@m.gmane.org; Thu, 16 May 2019 08:04:50 -0400 Original-Received: from eggs.gnu.org ([209.51.188.92]:44787) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hRF5v-0002EB-Sg for emacs-devel@gnu.org; Thu, 16 May 2019 08:02:46 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hREuN-0008LB-1N for emacs-devel@gnu.org; Thu, 16 May 2019 07:50:47 -0400 Original-Received: from mail1431c50.megamailservers.eu ([91.136.14.31]:57812 helo=mail118c50.megamailservers.eu) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hREuM-0008DC-8C for emacs-devel@gnu.org; Thu, 16 May 2019 07:50:46 -0400 X-Authenticated-User: mattiase@bredband.net DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=megamailservers.eu; s=maildub; t=1557998968; bh=ajr9Z61i79DI8NWPuIPBIXpbFAOue/Yi5MiRlvN68OM=; h=Subject:From:In-Reply-To:Date:Cc:References:To:From; b=QIHwdz2T7LQ8c0by3npaPuDrhKn+ogbZv/mZOKmgSwQ96X60xFcdKFUIlgTxXRrYO A+ksK1hKeKMr93WjNO088eFXhg6GbKaSVYtmrILTVVLOFIQliD8qOSlbySmS6tKoET rrZfwSIPsgie9H2fi/vB3JPY6O5fP+jLxGHlLpp8= Feedback-ID: mattiase@acm.or Original-Received: from [192.168.1.65] (c-e636e253.032-75-73746f71.bbcust.telenor.se [83.226.54.230]) (authenticated bits=0) by mail118c50.megamailservers.eu (8.14.9/8.13.1) with ESMTP id x4G9TPPS024329; Thu, 16 May 2019 09:29:27 +0000 In-Reply-To: <84fcfdce-39d7-1ebb-c0c7-98aa05854646@lsv.fr> X-Mailer: Apple Mail (2.3445.104.8) X-CTCH-RefID: str=0001.0A0B020D.5CDD2D77.0088, ss=1, re=0.000, recu=0.000, reip=0.000, cl=1, cld=1, fgs=0 X-CTCH-VOD: Unknown X-CTCH-Spam: Unknown X-CTCH-Score: 0.000 X-CTCH-Flags: 0 X-CTCH-ScoreCust: 0.000 X-CSC: 0 X-CHA: v=2.3 cv=PfPReBpd c=1 sm=1 tr=0 a=M+GU/qJco4WXjv8D6jB2IA==:117 a=M+GU/qJco4WXjv8D6jB2IA==:17 a=jpOVt7BSZ2e4Z31A5e1TngXxSK0=:19 a=kj9zAlcOel0A:10 a=WvqRJYt3MJtYUkcDbgIA:9 a=CjuIK1q_8ugA:10 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x (no timestamps) [generic] X-Received-From: 91.136.14.31 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:236572 Archived-At: 16 maj 2019 kl. 08.57 skrev phs : >=20 > The regular expression "*", instead of matching zero-or-more = occurrences > of the empty string, behaves as "\*" or "[*]" and only matches the * > character. >=20 > I believe this is a bug, not a feature, and in any case the Emacs = manual > does not document this behavior. Actually this one is documented: For historical compatibility, special characters are treated as = ordinary ones if they are in contexts where their special meanings make no = sense. For example, `*foo' treats `*' as ordinary since there is no preceding expression on which the `*' can act. and in any case the 'correct' behaviour would be to signal a syntax = error, not repeat the empty string. > If this behavior is the expected one, then (rx (0+ "")) should not > return "*". Thanks for reporting it, and you are right, that's a (known) bug in rx.