From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: Alan Mackenzie Newsgroups: gmane.emacs.devel Subject: Re: [Patch]: Allow overlay arrows to be inserted before the text at column zero rather than splatting it. Date: Mon, 19 Aug 2019 19:28:29 +0000 Message-ID: <20190819192829.GB30372@ACM> References: <20190818134804.GA31509@ACM> <83mug6mtjy.fsf@gnu.org> <20190818161530.GB31509@ACM> <83imqumo7i.fsf@gnu.org> <20190818184356.GC31509@ACM> <83a7c6mhjw.fsf@gnu.org> <20190818192310.GD31509@ACM> <838srpnazt.fsf@gnu.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="256828"; mail-complaints-to="usenet@blaine.gmane.org" User-Agent: Mutt/1.10.1 (2018-07-13) Cc: emacs-devel@gnu.org To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Mon Aug 19 21:28:48 2019 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([209.51.188.17]) by blaine.gmane.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1hznKh-0014Yb-Rn for ged-emacs-devel@m.gmane.org; Mon, 19 Aug 2019 21:28:47 +0200 Original-Received: from localhost ([::1]:56888 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1hznKb-0004rA-BC for ged-emacs-devel@m.gmane.org; Mon, 19 Aug 2019 15:28:41 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:37191) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1hznKU-0004r0-Lf for emacs-devel@gnu.org; Mon, 19 Aug 2019 15:28:35 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hznKT-0002Iq-Fe for emacs-devel@gnu.org; Mon, 19 Aug 2019 15:28:34 -0400 Original-Received: from colin.muc.de ([193.149.48.1]:50069 helo=mail.muc.de) by eggs.gnu.org with smtp (Exim 4.71) (envelope-from ) id 1hznKT-0002IB-62 for emacs-devel@gnu.org; Mon, 19 Aug 2019 15:28:33 -0400 Original-Received: (qmail 68367 invoked by uid 3782); 19 Aug 2019 18:35:47 -0000 Original-Received: from acm.muc.de (p4FE15EF9.dip0.t-ipconnect.de [79.225.94.249]) by colin.muc.de (tmda-ofmipd) with ESMTP; Mon, 19 Aug 2019 20:35:46 +0200 Original-Received: (qmail 30699 invoked by uid 1000); 19 Aug 2019 19:28:29 -0000 Content-Disposition: inline In-Reply-To: <838srpnazt.fsf@gnu.org> X-Delivery-Agent: TMDA/1.1.12 (Macallan) X-Primary-Address: acm@muc.de X-detected-operating-system: by eggs.gnu.org: FreeBSD 9.x [fuzzy] X-Received-From: 193.149.48.1 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.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.org gmane.emacs.devel:239467 Archived-At: Hello, Eli. On Mon, Aug 19, 2019 at 05:29:42 +0300, Eli Zaretskii wrote: > > Date: Sun, 18 Aug 2019 19:23:10 +0000 > > Cc: emacs-devel@gnu.org > > From: Alan Mackenzie > > > Sorry, I'm confused now: how can you insert the arrow without either > > > moving the rest of the line to the right or overwriting its first few > > > glyphs? Where does the space for the arrow come from? > > Sorry for being a bit inexact. In that bit I meant inserting "=>" by > > overwriting the two characters in columns 0 and 1. We need to be able > > to do this. > But AFAIR that's exactly what the current implementation of > overlay-arrow on TTY frames does. It is. I was talking here about the putative superseding of the overlay arrow with (?higher level?) code using the display property in place of the overlay arrow's current, ugly, mechanism. It seems I switched over the subject I was talking about without making this clear. Sorry. The subject I started with at the beginning of the thread was extending the overlay arrow mechanism with my patch to xdisp.c. I can understand people not liking this patch. > So how exactly is your implementation different in this regard, and > why did you need any new code for it? The patch I proposed would have allowed the overlay arrow's mechanism to be used to _insert_ "=>" before column zero on a line (rather than overwriting the first two characters). The general feeling in this thread is that I should rethink this patch, instead using before-string overlay properties. This would enable me to close bug #36832 (The one about not wanting to scroll the compilation mode buffer on typing CR) satisfactorally. I intend to do this in the coming days. > Still confused. I'll try to be a bit more considerate in future threads, when my thinking starts getting unstable, and there's a danger of me zipping between confusingly related, but different, topics. I hope this thread has become at least moderately clear, now. -- Alan Mackenzie (Nuremberg, Germany).