From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Stefan Monnier via "Bug reports for GNU Emacs, the Swiss army knife of text editors" Newsgroups: gmane.emacs.bugs Subject: bug#56682: Fix the long lines font locking related slowdowns Date: Wed, 03 Aug 2022 16:33:24 -0400 Message-ID: References: <8c7321f2f3400a5db9be@heytings.org> <8c7321f2f388e5343475@heytings.org> <6ea376f6-d503-06d8-6d83-50c52b695394@yandex.ru> <8c7321f2f3ac52bfee4b@heytings.org> <8c7321f2f3ec1ef81af9@heytings.org> <02e83b0e-1b5c-fe75-6e59-1f8ddff82d37@yandex.ru> <96f28fd8-6744-1925-0631-0095099362dd@yandex.ru> <74ddc877f1e81f399eea@heytings.org> <74ddc877f14320d7852f@heytings.org> <5f6988c781f1253541e3@heytings.org> Reply-To: Stefan Monnier Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="27708"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/29.0.50 (gnu/linux) Cc: 56682@debbugs.gnu.org, Eli Zaretskii , Dmitry Gutov To: Gregory Heytings Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Wed Aug 03 22:34:12 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 1oJL4E-0006vK-5t for geb-bug-gnu-emacs@m.gmane-mx.org; 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Wed, 03 Aug 2022 20:34:02 +0000 Original-Received: (at 56682) by debbugs.gnu.org; 3 Aug 2022 20:33:40 +0000 Original-Received: from localhost ([127.0.0.1]:50030 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1oJL3k-0004wS-At for submit@debbugs.gnu.org; Wed, 03 Aug 2022 16:33:40 -0400 Original-Received: from mailscanner.iro.umontreal.ca ([132.204.25.50]:37688) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1oJL3h-0004wD-57 for 56682@debbugs.gnu.org; Wed, 03 Aug 2022 16:33:38 -0400 Original-Received: from pmg3.iro.umontreal.ca (localhost [127.0.0.1]) by pmg3.iro.umontreal.ca (Proxmox) with ESMTP id 6078944220B; Wed, 3 Aug 2022 16:33:31 -0400 (EDT) Original-Received: from mail01.iro.umontreal.ca (unknown [172.31.2.1]) by pmg3.iro.umontreal.ca (Proxmox) with ESMTP id E8C5944157B; Wed, 3 Aug 2022 16:33:29 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=iro.umontreal.ca; s=mail; t=1659558809; bh=DGcUuaaBzYaA6/so19wYEYZkgxFVMiyDRo6p7DRzkzM=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=T9o43IidOEOPgjx7Cf+npPKJiojVLpDYyskDibJoj5IStW+FfZTIijetZI7wm0IkZ m5FWuXxagiYj7WlskiNLqHK2mm6om+m0EYI4t/RhxZSaP+nIkCRtJEMgtSyiFkHEGO GKuTHMkLvOjy7toNW/kg3jKzLiJ8SiVK38yyd4qX5aFN9859EPoaCpxtfDnj97u6bJ IffAA2sPdiT6plZJ+hFj+yk2J0FzmQfiCSBSjIY94QAvO9NHxyozZq12dOMjsNzifU WfIcUYaXoLjtyjgIGXaop+yIL5tu//j5wD3FLoRtpy6jx9CqF9qtJkpCSmVJSuGuwr QoOmkjcsK18rQ== Original-Received: from milanesa (unknown [46.44.221.102]) by mail01.iro.umontreal.ca (Postfix) with ESMTPSA id 0BB95120302; Wed, 3 Aug 2022 16:33:28 -0400 (EDT) In-Reply-To: <5f6988c781f1253541e3@heytings.org> (Gregory Heytings's message of "Wed, 03 Aug 2022 09:04:03 +0000") 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:238649 Archived-At: > I'd say it is realistic, based on the observation that half of the > programming language modes in core do use widen, which they weren't supposed > to do. AFAICT, most uses of widen in lisp/progmodes is *not* within code related to font-lock (unsurprinsingly, since font-lock.el has been widening "for ever", so widening in the major mode has always been redundant). > But this discussion is leading nowhere. If you could point out to an > actual (or even potential) problem caused by this locked narrowing, > apart from an occasional mis-fontification, that would perhaps help it > to advance. If I were maintainer I'd just refuse such a change without corresponding escape hatch, based on the experience gained over the years about how Emacs is and should be designed. As a package contributor I just find it offensive that the C code would go to extra trouble in order to cut me out under the premise that "Elisp programmers would take the habit of using (widen-unlock) instead of (widen) in their programs", which I read as "we have to protect ELisp contributors from themselves". Also, I'm trying to imagine scenario that leads to such an abuse: - under normal circumstances, there are no long lines, so they'll never hit a "locked" narrowing and it will thus never occur to them to use a `widen-unlock`. - when they get a bug report with a locked narrowing because of long lines, using `widen-unlock` naively is likely to lead to an immediate performance problem, so it's unlikely they'll use it. I just don't buy it. Stefan