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 a way to know if this-command altered the buffer? Date: Wed, 12 May 2021 07:39:39 +0200 Message-ID: <87sg2swlwk.fsf@mbork.pl> References: <87tun8wrqt.fsf@mbork.pl> <87sg2sa85u.fsf@zoho.eu> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="24056"; 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 Wed May 12 07:43:26 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 1lgheY-00067P-PT for geh-help-gnu-emacs@m.gmane-mx.org; Wed, 12 May 2021 07:43:26 +0200 Original-Received: from localhost ([::1]:37680 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lgheX-0003L4-NJ for geh-help-gnu-emacs@m.gmane-mx.org; Wed, 12 May 2021 01:43:25 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:34106) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lghbI-0005a6-26 for help-gnu-emacs@gnu.org; Wed, 12 May 2021 01:40:04 -0400 Original-Received: from mail.mojserwer.eu ([195.110.48.8]:55072) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lghb7-00084r-65 for help-gnu-emacs@gnu.org; Wed, 12 May 2021 01:40:03 -0400 Original-Received: from localhost (localhost [127.0.0.1]) by mail.mojserwer.eu (Postfix) with ESMTP id 11567E6590; Wed, 12 May 2021 07:39:46 +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 9NS5zH7FQ-zK; Wed, 12 May 2021 07:39:40 +0200 (CEST) Original-Received: from localhost (178235147191.dynamic-3-poz-k-0-1-0.vectranet.pl [178.235.147.191]) by mail.mojserwer.eu (Postfix) with ESMTPSA id C5182E6209; Wed, 12 May 2021 07:39:39 +0200 (CEST) In-reply-to: <87sg2sa85u.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:129715 Archived-At: On 2021-05-12, at 06:27, Emanuel Berg via Users list for the GNU Emacs text editor wrote: > Marcin Borkowski wrote: > >> I want to run some function in a certain hook. This function >> will update some info displayed using an overlay. The info >> depends on the buffer contents and is pretty expensive to >> compute, so I'd like to only display it if the buffer >> really changed. >> >> Is there a way to know if `this-command' actually changed >> the buffer (as opposed to e.g. point motion)? > > Maybe these > > buffer-chars-modified-tick > buffer-modified-tick Wow, I never heard about those! Interesting! Though I think I found the best answer (after-change-functions), this is also very interesting and possibly useful (though in other circumstances, I think). Thanks! -- Marcin Borkowski http://mbork.pl