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: Thu, 16 May 2019 12:54:30 +0200 Message-ID: References: <7a6b23f52418b093a4cf7a6db4306cf425533249.camel@acm.org> <20190515194129.GA4103@ACM> 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="96617"; mail-complaints-to="usenet@blaine.gmane.org" Cc: Stefan Monnier , emacs-devel@gnu.org To: Alan Mackenzie Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Thu May 16 12:54:54 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 1hRE2I-000P1g-3s for ged-emacs-devel@m.gmane.org; Thu, 16 May 2019 12:54:54 +0200 Original-Received: from localhost ([127.0.0.1]:51951 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hRE2G-0007ds-UW for ged-emacs-devel@m.gmane.org; Thu, 16 May 2019 06:54:52 -0400 Original-Received: from eggs.gnu.org ([209.51.188.92]:55649) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hRE22-0007bU-RD for emacs-devel@gnu.org; Thu, 16 May 2019 06:54:39 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hRE21-0003wt-E7 for emacs-devel@gnu.org; Thu, 16 May 2019 06:54:38 -0400 Original-Received: from mail78c50.megamailservers.eu ([91.136.10.88]:33144 helo=mail70c50.megamailservers.eu) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hRE20-0003uJ-JL for emacs-devel@gnu.org; Thu, 16 May 2019 06:54:37 -0400 X-Authenticated-User: mattiase@bredband.net DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=megamailservers.eu; s=maildub; t=1558004074; bh=8dIHGLizoZQQTG26GS9VBpVrO7f5NzedTV+ubrHP4Bs=; h=Subject:From:In-Reply-To:Date:Cc:References:To:From; b=BHw2gD+TQ9ozVd9EK2VK08o/6U1J1u4R6Vh37xmvELRnF4efOkAy0XN0ZHNjp/aj4 DOMANWjt9bgHsJ1AsoqkQr3sY+cfRm/8qXLUuNR/rfueBY3uyEFUduTMwMVLfpK8fV RPSHruqBdm9pqergtRNRPIS7j75lJsyK0LCkmWmI= 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 mail70c50.megamailservers.eu (8.14.9/8.13.1) with ESMTP id x4GAsVVR031684; Thu, 16 May 2019 10:54:32 +0000 In-Reply-To: <20190515194129.GA4103@ACM> X-Mailer: Apple Mail (2.3445.104.8) X-CTCH-RefID: str=0001.0A0B0208.5CDD416A.0005, 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=epTxMLhX c=1 sm=1 tr=0 a=M+GU/qJco4WXjv8D6jB2IA==:117 a=M+GU/qJco4WXjv8D6jB2IA==:17 a=jpOVt7BSZ2e4Z31A5e1TngXxSK0=:19 a=kj9zAlcOel0A:10 a=yz3S5198z79HRBQPGoAA: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: 91.136.10.88 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:236569 Archived-At: 15 maj 2019 kl. 21.41 skrev Alan Mackenzie : >=20 > I think regexp-unmatchable is too much of a mouthful. It is more > difficult to type that a\\` (or whatever), even after having to think > where the seldom used keys are on the keyboard. Also it is difficult = to > spell. is it unmatchable or unmatcheable? >=20 > I would suggest re-nomatch (or possibly nomatch-re), which is just 10 > characters, as opposed to your suggestion which is 18. Quite = possibly, > re-nomatch is easier to type than a\\` (or whatever). Thanks Alan, and you may have a point. I'm definitely not against a = better name if there is a consensus for it. Let me just dispassionately note that: 1. As 'match' does not end in 'e', there is no more reason to write 'unmatcheable' than 'undrinkeable'. 2. (rx (or)) is even shorter than re-nomatch, and is very memorable. (rx (|)) is shorter still. 3. Lisp tradition is unafraid of the verbose, partly because `-' is allowed in identifiers which lowers the friction. 4. The point of this name isn't to be shorter than the regexp string it represents, but to be more readable and avoid mistakes and substandard reinventions. Start bikeshedding; I'll try to low-pass filter.