GNU bug report logs - #54488
29.0.50; move-to-column/overlay-related regression in latest master, perhaps 28?

Previous Next

Full log

Message #92 received at 54488 <at> debbugs.gnu.org (full text, mbox):

From: Eli Zaretskii <eliz <at> gnu.org>
To: João Távora <joaotavora <at> gmail.com>
Cc: 54488 <at> debbugs.gnu.org, dgutov <at> yandex.ru
Subject: Re: bug#54488: 29.0.50; move-to-column/overlay-related regression
 in latest master, perhaps 28?
Date: Thu, 24 Mar 2022 17:29:25 +0200

> From: João Távora <joaotavora <at> gmail.com>
> Cc: dgutov <at> yandex.ru,  54488 <at> debbugs.gnu.org
> Date: Thu, 24 Mar 2022 15:01:30 +0000
> 
> Eli Zaretskii <eliz <at> gnu.org> writes:
> 
> > I see that you had problems reconciling the LSP idea of "columns" with
> > that of Emacs.  If LSP indeed works in UTF-16 (I don't know, but I
> > have no reason to doubt that), then I think your solution is decent,
> > although actually encoding stuff could be overhead: after all, whether
> > a given codepoint takes 1 or 2 UTF-16 code units can be easily
> > established by looking at the codepoints themselves.  But that's an
> > optimization.
> 
> An interesting one, though.  I think I follow.  Is there some easy way
> in Emacs to measure how many UTF-16 code units a given codepoint takes?

That's easy: any codepoint above #xFFFF needs 2 UTF-16 code units.

> I'm afraid I evicted this knowledge from the cache since I made that fix
> 2,5 years ago... Is a "codepoint" here a character in a string/buffer?

Yes.

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.