From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Daniel Mendler Newsgroups: gmane.emacs.bugs Subject: bug#55205: 28.1.50; completion--replace illegally mutates completion candidates Date: Mon, 2 May 2022 18:38:37 +0200 Message-ID: <698d2a57-db2a-1c8a-5fe1-305b1c37aea2@daniel-mendler.de> References: <4d1b8687-20f2-137a-2739-7bba28828991@daniel-mendler.de> <87wnf5mpt4.fsf@gnus.org> <835ymp78hl.fsf@gnu.org> <834k276gyd.fsf@gnu.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="35853"; mail-complaints-to="usenet@ciao.gmane.io" Cc: larsi@gnus.org, 55205@debbugs.gnu.org To: Stefan Monnier , Eli Zaretskii Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Mon May 02 18:39:13 2022 Return-path: Envelope-to: geb-bug-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 1nlZ4q-00091r-Sh for geb-bug-gnu-emacs@m.gmane-mx.org; Mon, 02 May 2022 18:39:12 +0200 Original-Received: from localhost ([::1]:45862 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nlZ4p-0003J7-Lb for geb-bug-gnu-emacs@m.gmane-mx.org; Mon, 02 May 2022 12:39:11 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:48428) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nlZ4g-0003Iz-C4 for bug-gnu-emacs@gnu.org; Mon, 02 May 2022 12:39:02 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]:43944) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1nlZ4f-00030Q-Md for bug-gnu-emacs@gnu.org; Mon, 02 May 2022 12:39:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1nlZ4f-00005B-Jl for bug-gnu-emacs@gnu.org; Mon, 02 May 2022 12:39:01 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Daniel Mendler Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Mon, 02 May 2022 16:39:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 55205 X-GNU-PR-Package: emacs Original-Received: via spool by 55205-submit@debbugs.gnu.org id=B55205.165150952632762 (code B ref 55205); Mon, 02 May 2022 16:39:01 +0000 Original-Received: (at 55205) by debbugs.gnu.org; 2 May 2022 16:38:46 +0000 Original-Received: from localhost ([127.0.0.1]:37841 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1nlZ4Q-0008WM-Hk for submit@debbugs.gnu.org; Mon, 02 May 2022 12:38:46 -0400 Original-Received: from server.qxqx.de ([178.63.65.180]:47103 helo=mail.qxqx.de) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1nlZ4P-0008W8-3D for 55205@debbugs.gnu.org; Mon, 02 May 2022 12:38:45 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=qxqx.de; s=mail1392553390; h=Content-Transfer-Encoding:Content-Type:In-Reply-To:From: References:Cc:To:Subject:MIME-Version:Date:Message-ID:Sender:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=AKiNPzmJLc32JFGCtjxC+WXfQw8+8X/zsCVg09Yl1D0=; b=SW0PgikCF/Xxlu1EXTB2PT+zpn CVY8Dg9//ztXauUDXpW9Nd6mysaGznVfCFPZjMJcH9uMBWmTOVCrrEalj0/gvRodEalTsTdExJZW7 w40iwgSSZ3ILr7ofp5kKi60J2wAexENaUrTKoA/DzYWolcWdnQdQT2QQkTCLk9Zt25ls=; Content-Language: en-US In-Reply-To: X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: "bug-gnu-emacs" Xref: news.gmane.io gmane.emacs.bugs:231269 Archived-At: On 5/2/22 18:34, Stefan Monnier wrote: >> Completion takes text typed by the user and produces strings that the >> user could possibly mean by typing what he/she typed. Some part(s) of >> the candidates can legitimately come from what the user typed, some >> other part(s) could be invented by the completion machinery more or >> less out of thin air. Why should anyone expect this meat-grinder to >> refrain from destructively modifying any of the involved strings? > > Because the overwhelming majority of strings are never modified. > It's very unusual to modify a string by side effect (as opposed to > creating a new string object via `concat`, `substring`, ...). > This is true in most languages, AFAICT, but it's definitely true in > ELisp. One should add that *by definition* of the completion API, mutations of the supplied candidate strings don't take place. For example you can run completion on strings from the obarray: (completing-read "Symbol: " obarray) It would be quite harmful if the symbol names are destroyed in the process. I don't see the completion API as a meat-grinder. It is all quite well-defined. Daniel