From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: Andy Moreton Newsgroups: gmane.emacs.devel Subject: Re: 7 logical-xor implementations in source tree Date: Tue, 23 Jul 2019 11:26:18 +0100 Message-ID: References: <87tvbd9a8p.fsf@oremacs.com> <86wog9gn5n.fsf@gmail.com> <7AAB8009-DD68-4EA7-93CC-3B4A89FC8AFD@acm.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="98129"; mail-complaints-to="usenet@blaine.gmane.org" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.0.50 (windows-nt) To: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Tue Jul 23 12:26:35 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 1hps09-000PPK-W7 for ged-emacs-devel@m.gmane.org; Tue, 23 Jul 2019 12:26:34 +0200 Original-Received: from localhost ([::1]:40918 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hps08-0003S5-Rx for ged-emacs-devel@m.gmane.org; Tue, 23 Jul 2019 06:26:32 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:34059) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hps05-0003Rj-AH for emacs-devel@gnu.org; Tue, 23 Jul 2019 06:26:30 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hps04-0006tE-9x for emacs-devel@gnu.org; Tue, 23 Jul 2019 06:26:29 -0400 Original-Received: from 195-159-176-226.customer.powertech.no ([195.159.176.226]:42986 helo=blaine.gmane.org) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hps04-0006rq-1m for emacs-devel@gnu.org; Tue, 23 Jul 2019 06:26:28 -0400 Original-Received: from list by blaine.gmane.org with local (Exim 4.89) (envelope-from ) id 1hps01-000PHm-2q for emacs-devel@gnu.org; Tue, 23 Jul 2019 12:26:25 +0200 X-Injected-Via-Gmane: http://gmane.org/ Cancel-Lock: sha1:vSV2xkCqN66UB8+GC+J1tzTzOMs= X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 195.159.176.226 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:238830 Archived-At: On Tue 23 Jul 2019, Mattias Engdegård wrote: > 23 juli 2019 kl. 10.39 skrev Andy Moreton : >> >> Is `logxor' what you are looking for ? Removing duplication would be >> useful. > > Pretty sure he meant boolean (nil/non-nil) xor, not bitwise xor. Yes. The naming of the bitwise operations `logand', `logior', `logxor' and `lognot' is unfortunate. > Some naïve suggestions: > > * Call it `xor', to go with `and' and `or' > * Make it n-adic, taking at least 1 argument (since the operation has no identity) > * Make it a function, so that it can be used with `apply' etc. > * Give it a compiler macro, for efficient partial application Perhaps an `xor' special form in eval.c next to `and' and `or' ? AndyM