From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: How to add pseudo vector types Date: Thu, 29 Jul 2021 19:21:12 +0300 Message-ID: <83fsvxrszr.fsf@gnu.org> References: <83h7gw6pyj.fsf@gnu.org> <46BBFF88-76C3-4818-8805-5437409BEA93@gmail.com> <83wnpq46uk.fsf@gnu.org> <533BD53B-4E85-4E9E-B46A-346A5BBAD0F5@gmail.com> <258CB68D-1CC1-42C8-BDCD-2A8A8099B783@gmail.com> <1a776770-50b7-93cd-6591-c9a5b3a56eb8@gmail.com> <8335s64v10.fsf@gnu.org> <5380C92B-6C15-4490-A1E0-1C3132DBB16A@gmail.com> <83k0li2shw.fsf@gnu.org> <86wnpg82v3.fsf@stephe-leake.org> <83lf5wyn0z.fsf@gnu.org> <86pmv66yqg.fsf@stephe-leake.org> <83a6maw705.fsf@gnu.org> <83r1fluikh.fsf@gnu.org> <88007ACB-31E5-440F-876D-9F43C8EE02CC@gmail.com> <86fsw05lom.fsf@stephe-leake.org> <8A3823DD-5D5A-4A33-8EF9-93F05497CE4C@gmail.com> <864kcf5cmv.fsf_-_@stephe-leake.org> <18D745F5-DBB1-46CC-91D3-4ADAA9D37AB9@gmail.com> <834kcetmly.fsf@gnu.org> <831r7itjc8.fsf@gnu.org> <24808548-23F4-4068-877E-37C7190A02B0@gmail.com> <83wnpas1q7.fsf@gnu.org> <83k0l9rvf5.fsf@gnu.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="13269"; mail-complaints-to="usenet@ciao.gmane.io" Cc: cpitclaudel@gmail.com, stephen_leake@stephe-leake.org, monnier@iro.umontreal.ca, emacs-devel@gnu.org To: Yuan Fu Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Thu Jul 29 18:22:23 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 1m98ne-00038k-BB for ged-emacs-devel@m.gmane-mx.org; Thu, 29 Jul 2021 18:22:22 +0200 Original-Received: from localhost ([::1]:46218 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1m98nd-0007Ws-B0 for ged-emacs-devel@m.gmane-mx.org; Thu, 29 Jul 2021 12:22:21 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:32966) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m98mu-0006nO-MB for emacs-devel@gnu.org; Thu, 29 Jul 2021 12:21:36 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:41468) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1m98ms-0002oF-Uz; Thu, 29 Jul 2021 12:21:34 -0400 Original-Received: from 84.94.185.95.cable.012.net.il ([84.94.185.95]:4679 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m98ms-00043U-Fa; Thu, 29 Jul 2021 12:21:34 -0400 In-Reply-To: (message from Yuan Fu on Thu, 29 Jul 2021 11:57:56 -0400) 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:271792 Archived-At: > From: Yuan Fu > Date: Thu, 29 Jul 2021 11:57:56 -0400 > Cc: Stephen Leake , > Clément Pit-Claudel , > monnier@iro.umontreal.ca, > emacs-devel@gnu.org > > >> Anyway, I found a way that avoids this issue: the bounds of tree-sitter’s visible region never changes, and the next time when lisp narrows to a different region, we update tree-sitter’s bound to match that of the narrowing. Here is the latest patch. If the code is not entirely straightforward, I’m happy to add more comment to explain it. > > > > I'm not sure we should do this, because it means we second-guess what > > the Lisp program calling TS intends to do. Why should we do that, > > instead of leaving it to the Lisp program to DTRT? And what happens > > if our guess is wrong? > > I don’t think the current implementation guesses anything. Let me turn around and ask you what is TRT: if the buffer is xxxAAAxxx, and lisp narrows to AAA and creates a parser, parser sees AAA; now widen, user inserts BBB in front of AAA, what do we tell tree-sitter? Nothing changed, or BBB inserted at the beginning? Neither. We should tell TS that instead of AAA there's now xxxBBBAAAxxx, because the narrowing was removed. > To where should lisp narrow? BBBAAA, or AAA, or BBB? It's the question for the Lisp program, not for the low-level code which we are discussing. Anyway, you are once again bothered by a scenario that should not happen at all: a Lisp program should not call TS first with, then without narrowing (or the other way around). I don't see why such situation should happen, and if they do, the Lisp programs which need them will have to figure out what to do and how.