From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.ciao.gmane.io!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: emacs rendering comparisson between emacs23 and emacs26.3 Date: Mon, 06 Apr 2020 16:21:21 +0300 Message-ID: <83eet0sqb2.fsf@gnu.org> References: <86tv2h2vww.fsf@gmail.com> <20200322123818.GB32470@ACM> <87eetk5swm.fsf@gnu.org> <20200326193128.GC14092@ACM> <86d08y4zsx.fsf@gmail.com> <83sghs7qdz.fsf@gnu.org> <83h7y63sjj.fsf@gnu.org> <834ku43c61.fsf@gnu.org> <83k12zz6ds.fsf@gnu.org> <054393f3-3873-ab6e-b325-0eca354d8838@gmx.at> Injection-Info: ciao.gmane.io; posting-host="ciao.gmane.io:159.69.161.202"; logging-data="118984"; mail-complaints-to="usenet@ciao.gmane.io" Cc: rudalics@gmx.at, rrandresf@gmail.com, emacs-devel@gnu.org, acm@muc.de To: rms@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Mon Apr 06 15:22:21 2020 Return-path: Envelope-to: ged-emacs-devel@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 1jLRhk-000Ukf-Ky for ged-emacs-devel@m.gmane-mx.org; Mon, 06 Apr 2020 15:22:20 +0200 Original-Received: from localhost ([::1]:60084 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jLRhj-0007je-OM for ged-emacs-devel@m.gmane-mx.org; Mon, 06 Apr 2020 09:22:19 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:47650) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jLRh1-0007In-4M for emacs-devel@gnu.org; Mon, 06 Apr 2020 09:21:36 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:58365) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1jLRh0-0001FS-Cw; Mon, 06 Apr 2020 09:21:34 -0400 Original-Received: from [176.228.60.248] (port=3401 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1jLRgs-0002qu-VX; Mon, 06 Apr 2020 09:21:27 -0400 In-Reply-To: (message from Richard Stallman on Sun, 05 Apr 2020 22:36:20 -0400) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] 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-mx.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.io gmane.emacs.devel:246520 Archived-At: > From: Richard Stallman > Cc: acm@muc.de, eliz@gnu.org, rrandresf@gmail.com, emacs-devel@gnu.org > Date: Sun, 05 Apr 2020 22:36:20 -0400 > > > Recent Emacsen either ignore that variable or silently reset it to nil > > internally so it doesn't get into their way. Their progmodes either > > always scan an entire buffer from its beginning or use some elaborate, > > fragile techniques to find such a top level position. Moreover, our > > underlying mechanism for syntax highlighting always marks the entire > > rest of a buffer as dirty after every single editing change. This has > > the consequence that that entire part has to be continuously rescanned > > when some of it is shown in another window. > > Does anyone disagree with this specific factual claim? I'm not sure what is "the claim" here, but I want to point out a small inaccuracy: redisplay doesn't "continuously rescan the entire rest of the buffer", it only rescans the part(s) shown in windows. (It might happen that some major mode's font-lock definitions end up rescanning much more, but that's a separate issue.) And frankly, what would we like Emacs to do instead? A change in a buffer can potentially affect the fontification of the rest of the buffer, and I don't think we would like Emacs to fail to update other windows showing the same buffer -- that would be against Emacs's description as "real-time" editor.