GNU bug report logs - #24012
25.0.95; forward-comment backwards takes O(n^2)

Previous Next

Package: emacs;

Reported by: Leo Liu <sdl.web <at> gmail.com>

Date: Sun, 17 Jul 2016 11:05:02 UTC

Severity: normal

Found in version 25.0.95

Done: Stefan Kangas <stefan <at> marxist.se>

Bug is archived. No further changes may be made.

Full log

Message #11 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Andreas Röhler <andreas.roehler <at> easy-emacs.de>
To: bug-gnu-emacs <at> gnu.org
Subject: Re: bug#24012: 25.0.95; forward-comment backwards takes O(n^2)
Date: Sun, 17 Jul 2016 15:39:17 +0200


On 17.07.2016 13:04, Leo Liu wrote:
> 1. Use the attached file as an example, open it in emacs in ruby-mode
> 2. Move point to end of buffer and eval (forward-comment (- (point)))
>
> The last step takes about 0.25 seconds on my MacBook 3 GHz Intel Core
> i7. If you double the lines of comments, the time increase by 4 folds.
>
> Any idea why forward-comment backwards is so slow?
>
> Leo
>

With last line

### @end (forward-comment (- (point)))

evaluation last expression doesn't move backward at all, returns nil

GNU Emacs 25.0.95.1 (i686-pc-linux-gnu, GTK+ Version 3.14.5) of 2016-06-12
This bug report was last modified 5 years and 198 days ago.

Previous Next

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