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: regular expressions that match nothing Date: Sun, 19 May 2019 09:32:45 +0200 Message-ID: <0E7D1DF3-682F-4FB9-8378-FEA3E9FDE5E9@acm.org> References: <7a6b23f52418b093a4cf7a6db4306cf425533249.camel@acm.org> <87ftpefevf.fsf@ericabrahamsen.net> Mime-Version: 1.0 (Mac OS X Mail 12.4 \(3445.104.11\)) 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="235984"; mail-complaints-to="usenet@blaine.gmane.org" Cc: Emacs developers To: HaiJun Zhang Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Sun May 19 09:33:32 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 1hSGK3-000zHM-Hw for ged-emacs-devel@m.gmane.org; Sun, 19 May 2019 09:33:31 +0200 Original-Received: from localhost ([127.0.0.1]:45164 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hSGK2-0006UI-IH for ged-emacs-devel@m.gmane.org; Sun, 19 May 2019 03:33:30 -0400 Original-Received: from eggs.gnu.org ([209.51.188.92]:35427) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hSGJQ-0006UB-O7 for emacs-devel@gnu.org; Sun, 19 May 2019 03:32:53 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hSGJP-0007ho-TC for emacs-devel@gnu.org; Sun, 19 May 2019 03:32:52 -0400 Original-Received: from mail1430c50.megamailservers.eu ([91.136.14.30]:34892 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 1hSGJO-0007gB-9Z for emacs-devel@gnu.org; Sun, 19 May 2019 03:32:51 -0400 X-Authenticated-User: mattiase@bredband.net DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=megamailservers.eu; s=maildub; t=1558251167; bh=9jP8ke0YPB7+VHT+bewwFlKj4I7cpOpmBrAW1Jz457E=; h=Subject:From:In-Reply-To:Date:Cc:References:To:From; b=PDh6ruiW7oXmr590RVknwO/VHPOi5CosqXSIIQr41rqlavSqdWIJESV+cRmnGYHDb a+Oss9oiEe1i9JCTtPt2GsO78+C83+vhnmlg+mOuRuNa6qWOJdMCVs4hWf1J0kIa+B ynOPte30aBOInRPisDnASlQPVBy4yodht4lhQJBY= Feedback-ID: mattiase@acm.or Original-Received: from [192.168.0.4] ([188.150.171.71]) (authenticated bits=0) by mail118c50.megamailservers.eu (8.14.9/8.13.1) with ESMTP id x4J7WkI2005510; Sun, 19 May 2019 07:32:47 +0000 In-Reply-To: X-Mailer: Apple Mail (2.3445.104.11) X-CTCH-RefID: str=0001.0A0B0215.5CE1069F.006C, 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=SF+I6pRkHZhrawxbOkkvaA==:117 a=SF+I6pRkHZhrawxbOkkvaA==:17 a=jpOVt7BSZ2e4Z31A5e1TngXxSK0=:19 a=kj9zAlcOel0A:10 a=UqCG9HQmAAAA:8 a=kj66BZBYNzu1obcW7E0A: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: 91.136.14.30 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:236744 Archived-At: 19 maj 2019 kl. 07.00 skrev HaiJun Zhang : >=20 > > regexp-null? It's also a little cryptic, but it's short! >=20 > What about regexp-nothing or re-nothing? Those are fair suggestions and close to the mathematical meaning, but = could possibly be misunderstood as patterns (only) matching the empty = string.