From: Lars Ingebrigtsen <larsi@gnus.org>
To: Alan Mackenzie <acm@muc.de>
Cc: Marcin Borkowski <mbork@amu.edu.pl>, 19873@debbugs.gnu.org
Subject: bug#19873: Ill-formed regular expression is constructed in forward-paragraph.
Date: Fri, 03 Dec 2021 17:15:18 +0100 [thread overview]
Message-ID: <875ys5y8a1.fsf@gnus.org> (raw)
In-Reply-To: <YakwXbh40S/F7XII@ACM> (Alan Mackenzie's message of "Thu, 2 Dec 2021 20:45:17 +0000")
Alan Mackenzie <acm@muc.de> writes:
> Back when the bug was new, I started writing a library to analyse a
> regular expression and convert it into an equivalent well formed regular
> expression. It's actually working, but is incomplete. It's currently
> 2757 lines long, including pretty complete unit testing. I actually
> looked at it again at the start of November.
Interesting.
> It strikes me as one of these things which needs to be done
> systematically, which, as I said, I've already tried (and not yet given
> up). The question presents itself, would the effort be better spent
> improving Emacs's regexp engine?
Indeed -- making the Emacs regexp engine transform these complex regexps
into simpler, equivalent forms would be great. We wouldn't have to use
it on all regexps -- the problem usually rears its head when we're
combining several user-defined regexps into a large one, so if we had a
`simplify-regexp' function that we could stick in here, that'd solve the
issue here (and in similar circumstances elsewhere).
--
(domestic pets only, the antidote for overdose, milk.)
bloggy blog: http://lars.ingebrigtsen.no
prev parent reply other threads:[~2021-12-03 16:15 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-15 10:31 bug#19873: Ill-formed regular expression is constructed in forward-paragraph Alan Mackenzie
2017-02-26 16:44 ` Marcin Borkowski
2017-02-26 16:57 ` Eli Zaretskii
2017-02-26 18:48 ` Marcin Borkowski
2017-03-07 16:47 ` Eli Zaretskii
2017-03-09 21:04 ` Alan Mackenzie
2021-12-02 10:39 ` Lars Ingebrigtsen
2021-12-02 10:44 ` Lars Ingebrigtsen
2021-12-02 11:17 ` Lars Ingebrigtsen
2021-12-02 20:45 ` Alan Mackenzie
2021-12-03 16:15 ` Lars Ingebrigtsen [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
List information: https://www.gnu.org/software/emacs/
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=875ys5y8a1.fsf@gnus.org \
--to=larsi@gnus.org \
--cc=19873@debbugs.gnu.org \
--cc=acm@muc.de \
--cc=mbork@amu.edu.pl \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
Code repositories for project(s) associated with this public inbox
https://git.savannah.gnu.org/cgit/emacs.git
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).