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: 7 logical-xor implementations in source tree Date: Thu, 25 Jul 2019 19:46:04 +0200 Message-ID: <419E0AA6-77DB-4505-8F1E-9C43D8F8EDF3@acm.org> References: <87tvbd9a8p.fsf@oremacs.com> <87pnm14u95.fsf@tcd.ie> <87sgqvoz5c.fsf@tcd.ie> <87d0hz2e11.fsf@tcd.ie> <5B633129-B795-4BFA-AE81-FE9FD0A24CE9@acm.org> <93624180-bd67-926a-dd8c-757772e14eeb@cs.ucla.edu> Mime-Version: 1.0 (Mac OS X Mail 12.4 \(3445.104.11\)) Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="186585"; mail-complaints-to="usenet@blaine.gmane.org" Cc: "Basil L. Contovounesios" , Oleh Krehel , Stefan Monnier , emacs-devel@gnu.org To: Paul Eggert Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Thu Jul 25 19:46:34 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 (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1hqhp2-000mKs-Jj for ged-emacs-devel@m.gmane.org; Thu, 25 Jul 2019 19:46:32 +0200 Original-Received: from localhost ([::1]:34550 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hqhp1-00012q-Gp for ged-emacs-devel@m.gmane.org; Thu, 25 Jul 2019 13:46:31 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:52404) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hqhos-0000zG-Gi for emacs-devel@gnu.org; Thu, 25 Jul 2019 13:46:23 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hqhor-0005GA-Ir for emacs-devel@gnu.org; Thu, 25 Jul 2019 13:46:22 -0400 Original-Received: from mail221c50.megamailservers.eu ([91.136.10.231]:52780 helo=mail33c50.megamailservers.eu) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hqhoq-0005FP-U8 for emacs-devel@gnu.org; Thu, 25 Jul 2019 13:46:21 -0400 X-Authenticated-User: mattiase@bredband.net DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=megamailservers.eu; s=maildub; t=1564076768; bh=pLK2atNfvR1BxtCjHTHlBl2xNJTDOtvs0XyqUkQHq+Q=; h=Subject:From:In-Reply-To:Date:Cc:References:To:From; b=rDct68ZFL0rBkMUWUxC224AOfKFVjKjem1yvChLtwx/puZuUrgP9bc7dB+q+Fg4Sd O0ARcsfHpDVySTTigKoOWXLyjuv+/lpoRBzLt3Po0m0CFZ4teUWu8CHn4Bc7SunlWt +Et2nIovvFPhFUUqbpR30JJOUdP6VsaLNzC2rBkE= Feedback-ID: mattiase@acm.or Original-Received: from [192.168.0.4] ([188.150.171.71]) (authenticated bits=0) by mail33c50.megamailservers.eu (8.14.9/8.13.1) with ESMTP id x6PHk4Dn007820; Thu, 25 Jul 2019 17:46:06 +0000 In-Reply-To: <93624180-bd67-926a-dd8c-757772e14eeb@cs.ucla.edu> X-Mailer: Apple Mail (2.3445.104.11) X-CTCH-RefID: str=0001.0A0B020C.5D39EAE0.0033, 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=Ioswjo3g c=1 sm=1 tr=0 a=SF+I6pRkHZhrawxbOkkvaA==:117 a=SF+I6pRkHZhrawxbOkkvaA==:17 a=jpOVt7BSZ2e4Z31A5e1TngXxSK0=:19 a=IkcTkHD0fZMA:10 a=pwZt6RLBppmcoduhLvEA:9 a=QEXdDO2ut3YA:10 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x (no timestamps) [generic] X-Received-From: 91.136.10.231 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.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.org gmane.emacs.devel:238894 Archived-At: 25 juli 2019 kl. 19.28 skrev Paul Eggert : >=20 > Mattias Engdeg=C3=A5rd wrote: >> there are many ways of open-coding the logic depending on the = circumstances. (Examples from a simple pattern search at the end.) >=20 > Thanks for those examples: they form a compelling argument for adding = both 'equiv' and 'xor' (under whatever names we choose). Just don't draw too many conclusions from them, as they reflect the = search patterns used (or, fundamentally, my limited imagination). It's not even sure the author would think of the logic as `equiv' or = `xor' in every instance. For example (from a random package): > (cl-assert (eq compilation-result > (not (eq (car (last (car test))) 'vo))) This is detected as an xor pattern, but it's really an assertion of the = value of `compilation-result'.