From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Alan Mackenzie Newsgroups: gmane.emacs.devel Subject: Re: Major modes using `widen' is a good, even essential, programming practice. Date: Sun, 7 Aug 2022 14:59:06 +0000 Message-ID: References: <6ae35c9306ade07b4c45@heytings.org> <835yj4xhh7.fsf@gnu.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="14737"; mail-complaints-to="usenet@ciao.gmane.io" Cc: gregory@heytings.org, emacs-devel@gnu.org To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Sun Aug 07 16:59:46 2022 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 1oKhko-0003gt-Kp for ged-emacs-devel@m.gmane-mx.org; Sun, 07 Aug 2022 16:59:46 +0200 Original-Received: from localhost ([::1]:38078 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oKhkn-0002rp-GF for ged-emacs-devel@m.gmane-mx.org; Sun, 07 Aug 2022 10:59:45 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:37742) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oKhkF-00027f-Gc for emacs-devel@gnu.org; Sun, 07 Aug 2022 10:59:11 -0400 Original-Received: from colin.muc.de ([193.149.48.1]:30255 helo=mail.muc.de) by eggs.gnu.org with smtp (Exim 4.90_1) (envelope-from ) id 1oKhkD-0005dx-FO for emacs-devel@gnu.org; Sun, 07 Aug 2022 10:59:11 -0400 Original-Received: (qmail 96981 invoked by uid 3782); 7 Aug 2022 14:59:07 -0000 Original-Received: from acm.muc.de (p2e5d5157.dip0.t-ipconnect.de [46.93.81.87]) (using STARTTLS) by colin.muc.de (tmda-ofmipd) with ESMTP; Sun, 07 Aug 2022 16:59:07 +0200 Original-Received: (qmail 5288 invoked by uid 1000); 7 Aug 2022 14:59:06 -0000 Content-Disposition: inline In-Reply-To: <835yj4xhh7.fsf@gnu.org> X-Submission-Agent: TMDA/1.3.x (Ph3nix) X-Primary-Address: acm@muc.de Received-SPF: pass client-ip=193.149.48.1; envelope-from=acm@muc.de; helo=mail.muc.de X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.29 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:293211 Archived-At: Hello, Eli. On Sun, Aug 07, 2022 at 17:20:52 +0300, Eli Zaretskii wrote: > > Date: Sun, 7 Aug 2022 14:13:36 +0000 > > Cc: emacs-devel@gnu.org > > From: Alan Mackenzie > > > jit-lock-functions is an API, with a contract. CC Mode decided to break > > > that contract. > > Where, exactly are the terms of this supposed contract formulated? And > > which part of this supposed contract has CC Mode broken? > jit-lock calls the functions with two arguments, BEG and END, and > expects them to work only on that chunk of text. I don't think you really mean that. Consider the second jit-lock chunk at the beginning of xdisp.c. Fontifying that chunk involves looking back 1500 characters before BEG to see that it needs font-lock-comment-face. You might argue that that information will be in a cache anyway, but that's not dependable. Also, the (BEG END) region will typically get rounded up to whole lines, again "violating" that chunk. In principle, font-lock needs to look outside of (BEG END). > > If you find CC Mode too sluggish for you (I don't), then configure it to > > be faster and inaccurate by setting font-lock-maximum-decoration. > It doesn't help, IME. The mode is still slow. OK, I need to look at CC Mode with f-l-m-d 2. There are surely things which can be taken out of that. -- Alan Mackenzie (Nuremberg, Germany).