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: A strange issue with buffer-undo-list Date: Mon, 08 Mar 2021 22:43:15 +0100 Message-ID: <87a6rdiaoc.fsf@mbork.pl> References: <87o8gbqs28.fsf@mbork.pl> <8735xm2t3p.fsf@web.de> <87r1l4n2w8.fsf@mbork.pl> <874ki090ms.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="21636"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: mu4e 1.1.0; emacs 28.0.50 Cc: help-gnu-emacs@gnu.org To: Emanuel Berg Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Mon Mar 08 22:44:11 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 1lJNfc-0005Ru-Mt for geh-help-gnu-emacs@m.gmane-mx.org; Mon, 08 Mar 2021 22:44:08 +0100 Original-Received: from localhost ([::1]:34662 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lJNfb-0000yM-PC for geh-help-gnu-emacs@m.gmane-mx.org; Mon, 08 Mar 2021 16:44:07 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:50770) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lJNeu-0000sE-Ru for help-gnu-emacs@gnu.org; Mon, 08 Mar 2021 16:43:25 -0500 Original-Received: from mail.mojserwer.eu ([195.110.48.8]:58776) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lJNes-0007iG-W9 for help-gnu-emacs@gnu.org; Mon, 08 Mar 2021 16:43:24 -0500 Original-Received: from localhost (localhost [127.0.0.1]) by mail.mojserwer.eu (Postfix) with ESMTP id 62A34E6D7B; Mon, 8 Mar 2021 22:43:21 +0100 (CET) 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 qlbt9jOqOJmz; Mon, 8 Mar 2021 22:43:16 +0100 (CET) Original-Received: from localhost (178235147030.dynamic-3-poz-k-0-1-0.vectranet.pl [178.235.147.30]) by mail.mojserwer.eu (Postfix) with ESMTPSA id 58ECDE62F2; Mon, 8 Mar 2021 22:43:16 +0100 (CET) In-reply-to: <874ki090ms.fsf@zoho.eu> 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:128365 Archived-At: On 2021-02-25, at 06:28, Emanuel Berg via Users list for the GNU Emacs text= editor wrote: > Marcin Borkowski wrote: > >>>> Is there a way to get the "state" of the change group to >>>> only cancel it if it was not finished? >>> >>> I think yes, it's called `atomic-change-group' - see how >>> that macro is implemented. >> >> Ah, that's simple and clever. Thank you. >> >> Still, these "change groups" seem a strange feature to me - >> they are hardly ever used in Emacs itself, right? > > Maybe people just don't understand the docstring: > > Like =E2=80=98progn=E2=80=99 but perform BODY as an atomic change group. > This means that if BODY exits abnormally, all of its changes > to the current buffer are undone. This works regardless of > whether undo is enabled in the buffer. > > This mechanism is transparent to ordinary use of undo; > if undo is enabled in the buffer and BODY succeeds, the > user can undo the change normally. Well, I understand that. But isn't it strange that almost no code in Emacs itself uses this? Best, --=20 Marcin Borkowski http://mbork.pl