From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Dmitry Gutov Newsgroups: gmane.emacs.devel Subject: Re: Major modes using `widen' is a good, even essential, programming practice. Date: Sun, 7 Aug 2022 20:53:58 +0300 Message-ID: <651cad2f-3ce3-22dd-0829-38dd3c46ec40@yandex.ru> References: <6ae35c9306ade07b4c45@heytings.org> <835yj4xhh7.fsf@gnu.org> <83y1w0w0gk.fsf@gnu.org> <83pmhcvugm.fsf@gnu.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="24694"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.9.1 Cc: gregory@heytings.org, emacs-devel@gnu.org To: Eli Zaretskii , Alan Mackenzie Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Sun Aug 07 19:55:33 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 1oKkUv-0006IY-Gg for ged-emacs-devel@m.gmane-mx.org; Sun, 07 Aug 2022 19:55:33 +0200 Original-Received: from localhost ([::1]:43186 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oKkUu-0001s6-01 for ged-emacs-devel@m.gmane-mx.org; Sun, 07 Aug 2022 13:55:32 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:58436) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oKkTk-0001BE-5C for emacs-devel@gnu.org; Sun, 07 Aug 2022 13:54:20 -0400 Original-Received: from mail-wr1-x433.google.com ([2a00:1450:4864:20::433]:44991) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1oKkTi-0004gT-Mf; Sun, 07 Aug 2022 13:54:19 -0400 Original-Received: by mail-wr1-x433.google.com with SMTP id q30so8512551wra.11; Sun, 07 Aug 2022 10:54:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=sender:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=hrKsQPJWA4Np8GoaJ3t0aMPQ/s3gx67dfy94Ue2nIUE=; b=kP4qEXOKtKWa3t+8PQFI8DpBSiJgqfWbEp48JirsiCqSSm2LgBPpbPX1Jf4R+d7g0s 70HpiKwx5KROaJmk2Tc1kOCK+iFaq+z24XgafC64QWB3S2F0sBUBjZjH564XT4kOkVOW 8kzHviqOxn+2yQz2/0b1hfHSgvTA1sC8Pq+0RIc77By6sj8VeR6Y23yYYNpnBcaJgj3T 4qXef+Zwl78pRZ9proRcuYsgtjno+NPw3r4jIPXilcznHPnWf0gHBoHF7/yWTKFL5pbB NBoAo+cwndjpETbXED2Y8hhPkau4Nfx3yc839ziVIz5l9oMJMzvVQ6sPqmojfaOguwL5 OXnw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:sender:message-id:date:mime-version:user-agent :subject:content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=hrKsQPJWA4Np8GoaJ3t0aMPQ/s3gx67dfy94Ue2nIUE=; b=6MTZR6KetQvx0hMb/JIC/QqaBoXPK09rQvXo3FXzV236JC47j5I4OElyxomuCjT8+P WNEtAu2fLcbUIz9GPM0ujQRle1aoJ6vIKaB0kCDIuAvisWk9LXyik7rNVGOHgOXdwUtD iaC4hwKC7+Gcu45NkaZ6/o2z2XhYsbYIi/85ClxuPx3qLjX2Luo8BsgsTDUNldXveWB0 oX+VKQAqQJ/TJy4v+rrw7NBiUwSgE+BE6XKtDp2Bqugfdt6wrhYKDSE5MWgrhkwW3VFd cHx8TVYAW5EzlxUJcjhgFsT/DA5R8GeH+NBSiRV406AoBA8C0qZcQnQ1X/OsP2bNGvf+ HS+A== X-Gm-Message-State: ACgBeo0EPjYicr78v4he8nHLJgWLxCyWWIoKZKaPleej9GIsmrNpD0bD xQM6u7A7UjQcJL6YRmcNDFIqD9C/7EI= X-Google-Smtp-Source: AA6agR6pRheoR2VcfyqBFHgHbQ8F5JhqokhK6I+vpI9t+KGVLWEFwzhCQzu6UJewN/bFQP9fsVj+7w== X-Received: by 2002:a5d:4906:0:b0:21f:dc9:8c86 with SMTP id x6-20020a5d4906000000b0021f0dc98c86mr9265231wrq.285.1659894840362; Sun, 07 Aug 2022 10:54:00 -0700 (PDT) Original-Received: from [192.168.0.6] ([46.251.119.176]) by smtp.googlemail.com with ESMTPSA id be8-20020a05600c1e8800b003a3270735besm11457603wmb.28.2022.08.07.10.53.59 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 07 Aug 2022 10:54:00 -0700 (PDT) Content-Language: en-US In-Reply-To: <83pmhcvugm.fsf@gnu.org> Received-SPF: pass client-ip=2a00:1450:4864:20::433; envelope-from=raaahh@gmail.com; helo=mail-wr1-x433.google.com X-Spam_score_int: -14 X-Spam_score: -1.5 X-Spam_bar: - X-Spam_report: (-1.5 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FORGED_FROMDOMAIN=0.249, FREEMAIL_FROM=0.001, HEADER_FROM_DIFFERENT_DOMAINS=0.249, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=no 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:293222 Archived-At: On 07.08.2022 20:23, Eli Zaretskii wrote: >> What jit-lock/font-lock actually do at the moment is to widen, then use >> syntax-ppss, i.e. in effect scan from BOB. > Yes, and that's SLOOOWWWW! It's not slow on files of reasonable size. E.g. even if we take xdisp.c (the file I've seen referred to in complaints on CC Mode's speed), (benchmark 1 '(save-excursion (parse-partial-sexp (point-min) (point-max)))) reports 20-50 ms on my machine. And that result is cached too. So whatever perceived slowness is there, it most likely comes from other sources.