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: Fri, 30 Jul 2021 09:35:17 +0300 Message-ID: <83tukcqpga.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> Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="18922"; mail-complaints-to="usenet@ciao.gmane.io" Cc: casouri@gmail.com, emacs-devel@gnu.org, stephen_leake@stephe-leake.org, cpitclaudel@gmail.com, monnier@iro.umontreal.ca To: rms@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Fri Jul 30 08:36:19 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 1m9M83-0004k8-8E for ged-emacs-devel@m.gmane-mx.org; Fri, 30 Jul 2021 08:36:19 +0200 Original-Received: from localhost ([::1]:44176 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1m9M81-0001pn-Sk for ged-emacs-devel@m.gmane-mx.org; Fri, 30 Jul 2021 02:36:17 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:50594) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m9M7U-00017l-Gk for emacs-devel@gnu.org; Fri, 30 Jul 2021 02:35:44 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:33670) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1m9M7T-0007Jo-7R; Fri, 30 Jul 2021 02:35:43 -0400 Original-Received: from 84.94.185.95.cable.012.net.il ([84.94.185.95]:1099 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 1m9M7J-0005Xk-Vn; Fri, 30 Jul 2021 02:35:36 -0400 In-Reply-To: (message from Richard Stallman on Thu, 29 Jul 2021 20:35:33 -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:271827 Archived-At: > From: Richard Stallman > Cc: eliz@gnu.org, cpitclaudel@gmail.com, > stephen_leake@stephe-leake.org, monnier@iro.umontreal.ca, > emacs-devel@gnu.org > Date: Thu, 29 Jul 2021 20:35:33 -0400 > > I suggest we create a way for the program to declare the purpose for > each instance of narrowing. > > I know of two kinds of purposes for using narrowing. > > 1. To focus operations on syntactic entity in a buffer containing > other things which are essentially unrelated. Let's call this "semantic" narrowing. > > For instance, when Rmail narrows the file buffer to just one message, > that is semantic narrowing. Whatever is outside the buffer bounds is > unrelated to parsing the current message. > > 2. To show just part of the text you're looking at. This is a display > feature, usually temporary, and would be enabled or disabled by the > user. Let's call it "display" narrowing. So another way of discerning between the two is to distinguish the "Lisp narrowing" from the "user narrowing". > I don't think Emacs can tell heuristically which kind of narrowing a > program is doing. If we agree that the second kind is only done by the user, then no heuristic is needed. But I agree that having this recorded explicitly would be a good idea. We could provide something similar to prog-indentation-context for this purpose. > I propose we create a way for Lisp programs to declare when they do > semantic narrowing. They could specify markers for the beginning and > end of that narrowing. > > Facilities for parsing the buffer should heed semantic narrowing but > disregard display narrowing. > > Various kinds of semantic narrowing should be able to nest, and > display narrowing should be able to nest inside semantic narrowings. > > Comments or critiques? We had a long discussion of a similar proposal, see https://lists.gnu.org/archive/html/emacs-devel/2017-02/msg00765.html At the time, we were unable to come to an agreed-upon design, so this feature was never implemented in mainline Emacs. Maybe we should revisit it now.