From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Marcin Borkowski Newsgroups: gmane.emacs.help Subject: Re: Is there any difference between `equal' and `string=' for strings? Date: Tue, 24 Aug 2021 16:55:56 +0200 Message-ID: <87tujevqmb.fsf@mbork.pl> References: <875yw2vxqh.fsf@mbork.pl> <87v941domi.fsf@zoho.eu> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="11460"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: mu4e 1.1.0; emacs 28.0.50 Cc: help-gnu-emacs@gnu.org To: Jean Louis Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Tue Aug 24 16:56:48 2021 Return-path: Envelope-to: geh-help-gnu-emacs@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1mIXr6-0002oh-88 for geh-help-gnu-emacs@m.gmane-mx.org; Tue, 24 Aug 2021 16:56:48 +0200 Original-Received: from localhost ([::1]:54616 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mIXr5-0006oN-Az for geh-help-gnu-emacs@m.gmane-mx.org; Tue, 24 Aug 2021 10:56:47 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:33050) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mIXqZ-0006nr-7p for help-gnu-emacs@gnu.org; Tue, 24 Aug 2021 10:56:15 -0400 Original-Received: from mail.mojserwer.eu ([195.110.48.8]:58306) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mIXqT-0001Ze-CJ for help-gnu-emacs@gnu.org; Tue, 24 Aug 2021 10:56:14 -0400 Original-Received: from localhost (localhost [127.0.0.1]) by mail.mojserwer.eu (Postfix) with ESMTP id 4E868E6250; Tue, 24 Aug 2021 16:56:04 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at mail.mojserwer.eu Original-Received: from mail.mojserwer.eu ([127.0.0.1]) by localhost (mail.mojserwer.eu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id SYONyb8bSr65; Tue, 24 Aug 2021 16:55:59 +0200 (CEST) Original-Received: from localhost (83.8.191.61.ipv4.supernova.orange.pl [83.8.191.61]) by mail.mojserwer.eu (Postfix) with ESMTPSA id BCC8BE620C; Tue, 24 Aug 2021 16:55:59 +0200 (CEST) In-reply-to: Received-SPF: pass client-ip=195.110.48.8; envelope-from=mbork@mbork.pl; helo=mail.mojserwer.eu X-Spam_score_int: -25 X-Spam_score: -2.6 X-Spam_bar: -- X-Spam_report: (-2.6 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: "help-gnu-emacs" Xref: news.gmane.io gmane.emacs.help:132711 Archived-At: On 2021-08-20, at 07:25, Jean Louis wrote: > * Emanuel Berg via Users list for the GNU Emacs text editor [2021-08-20 02:04]: >> Marcin Borkowski wrote: >>=20 >> > Well, of course a string and a symbol can never be `equal', >> > but they can be `string=3D'. But what if both arguments >> > are strings? >>=20 >> ... and if both arguments are symbols? >>=20 >> (string=3D 'hi 'hi) ; t >>=20 >> (Why ever one would use `string=3D' for that.) >>=20 >> Yeah, it is a jungle all that ... > > How I understand it, it is good also for comparison of symbols as > strings.=20 > > (setq s1 "Jane") =E2=87=92 "Jane" > (setq s2 "Jane") =E2=87=92 "Jane" > (setq s3 "Doe") =E2=87=92 "Doe" > > Then this is how I understand the intended purpose: > > (string=3D s1 s2) =E2=87=92 t > (string=3D s1 s3) =E2=87=92 nil > > And of course you are free to compare empty symbols: > > (string=3D 'hi 'hi) =E2=87=92 t > > However by looking at the purpose it becomes all logical to me. It can even do (string=3D "hello" 'hello) =3D> t (Why could that be useful, I'm not sure.) --=20 Marcin Borkowski http://mbork.pl