From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Daniel Colascione Newsgroups: gmane.emacs.devel Subject: Re: cc-mode fontification feels random Date: Fri, 04 Jun 2021 12:33:25 -0700 Message-ID: <179d8841388.2816.cc5b3318d7e9908e2c46732289705cb0@dancol.org> References: <831r9iw473.fsf@gnu.org> <2d6d1cb0-2e8f-ceea-cb83-3bb840b65115@dancol.org> <83zgw6udxt.fsf@gnu.org> <87czt1zzns.fsf@gmail.com> <371647e9-9508-ae98-26f0-3649d7ba114e@dancol.org> <83o8clla1u.fsf@gnu.org> <179d874d918.2816.cc5b3318d7e9908e2c46732289705cb0@dancol.org> <83im2tl9cg.fsf@gnu.org> Mime-Version: 1.0 Content-Type: text/plain; format=flowed; charset="us-ascii" Content-Transfer-Encoding: 8bit Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="15483"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: AquaMail/1.29.2-1810 (build: 102900008) Cc: emacs-devel@gnu.org, monnier@iro.umontreal.ca, joaotavora@gmail.com To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Fri Jun 04 21:36:53 2021 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 1lpFch-0003pM-B1 for ged-emacs-devel@m.gmane-mx.org; Fri, 04 Jun 2021 21:36:52 +0200 Original-Received: from localhost ([::1]:49044 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lpFcf-00033r-9A for ged-emacs-devel@m.gmane-mx.org; Fri, 04 Jun 2021 15:36:49 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:57790) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lpFZa-0001Ij-RI for emacs-devel@gnu.org; Fri, 04 Jun 2021 15:33:38 -0400 Original-Received: from dancol.org ([96.126.100.184]:58028) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lpFZT-0005NR-I8; Fri, 04 Jun 2021 15:33:38 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=dancol.org; s=x; h=Content-Transfer-Encoding:Content-Type:MIME-Version:Subject: References:In-Reply-To:Message-ID:Date:CC:To:From:Sender:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=/DBob3yn7VmutqOkYlsrsvEg6mmDArd28ijsq42Z31s=; b=elQEyV9hIRVldkON4+KA/Hm+Qz YoHUj64aOAyJMXkXRz/1cmVWeqxad0G9uS3qOsFvc/c1wiA9H43vdenifViLJIKGuFmkgL3yfl6yF /2vuJHihLiO5ahB1HCdPb0fFR/PyueayzTE75eXvcAlK7x8pAKCql+98aPjdeZouynjAFW1Qu+lTt bIyMYn43vvn2fGBURgfBxK7pFonUUpe92a6zMnd86QkzOe0peKW69oC+waHyAtsGUo03EGRf0G3cn rOz56b+J2NbCn8RdOkH92UjGyRxTbJ99VDCurImkVtcDI+vuAtmqrl3xVXEV8s4kRS/ZlS+hUup/M cp9o5/JQ==; Original-Received: from 248.sub-174-204-83.myvzw.com ([174.204.83.248]:7423 helo=[100.107.68.200]) by dancol.org with esmtpsa (TLS1.2:ECDHE_RSA_CHACHA20_POLY1305:256) (Exim 4.89) (envelope-from ) id 1lpFZR-0004pC-Qk; Fri, 04 Jun 2021 12:33:29 -0700 In-Reply-To: <83im2tl9cg.fsf@gnu.org> Received-SPF: pass client-ip=96.126.100.184; envelope-from=dancol@dancol.org; helo=dancol.org X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action 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:270405 Archived-At: On June 4, 2021 12:26:47 PM Eli Zaretskii wrote: >> From: Daniel Colascione >> CC: , , >> Date: Fri, 04 Jun 2021 12:16:47 -0700 >> >>> I see no reason for copying, nor for making these tools aware of the >>> gap. At least tree-sitter allows the application to provide a >>> function through which tree-sitter will access the edited text. It >>> should be simple to write such a function, because on the C level we >>> always know where the gap is. >> >> So you propose providing a "char get_buffer_char(size_t POS)" function? >> That *is* copying If you run that over all values of POS, all you've done >> is make a slow and shitty memcpy. > > What do you think tree-sitter does with the fast copy you hand to it? > doesn't it walk it one character at a time? > > And if you studied the tree-sitter's internals, and it uses > get_buffer_char as a means of copying text into its own buffer, then > perhaps we could ask tree-sitter developers to avoid the copy and use > the text directly. Teaching TS to use a generic cursor interface would be great. > > >> So you want to amortize the call over several characters? Okay. Now you've >> reinvented buffer-substring. > > buffer-substring is not just a copy of a chunk of text, it's much > more. The variant without text properties doesn't do much. > Even if eventually we need to use a memory copy, that'll run > circles around buffer-substring, and will avoid triggering GC. Sure. I'm not opposed to adding an API that's basically a more efficient buffer substring for C callers. I'm just pointing out that the idea of giving TS "direct access" to a buffer without any copy at all doesn't make a lot of sense. > > >> Because any kind of "access" to the buffer that doesn't expose the gap is >> going to be a copy anyway. > > The regexp routines aren't. The regexp routines have Emacs specific knowledge. My argument doesn't apply to code we can customize for Emacs.