GNU bug report logs - #64128
regexp parser zero-width assertion bugs

Previous Next

Full log

View this message in rfc822 format

From: Paul Eggert <eggert <at> cs.ucla.edu>
To: Mattias Engdegård <mattias.engdegard <at> gmail.com>
Cc: Eli Zaretskii <eliz <at> gnu.org>, monnier <at> iro.umontreal.ca, 64128 <at> debbugs.gnu.org
Subject: bug#64128: regexp parser zero-width assertion bugs
Date: Mon, 19 Jun 2023 11:14:18 -0700

[Message part 1 (text/plain, inline)]

On 2023-06-18 13:26, Mattias Engdegård wrote:
> The manual is a bit hazy about what we actually promise, though.
> 
> As Paul notes, we must be able to document it and that might not be easy, so perhaps we shouldn't even try (to change, or document)?

Although it's not easy to document, we should do better. I gave that a 
shot by installing the attached patches into the master branch. These 
patches try to document current behavior, including warning about the 
squirrelly behavior you mention. If/when we fix the squirrelly behavior 
we can change that part of the manual accordingly.

The last of the three patches is merely a terminology change: it 
standardizes on the term "bracket expression" for regexps like [a-z]. 
Formerly the doc and comments were inconsistent about the terminology. 
It's better to stick with the POSIX term here, to avoid confusion. I 
myself got confused about this when editing the other two patches.

Comments welcome as usual.

[0001-Document-regular-expression-special-cases-better.patch (text/x-patch, attachment)]

[0002-Document-Emacs-vs-POSIX-REs.patch (text/x-patch, attachment)]

[0003-Call-them-bracket-expressions-more-consistently.patch (text/x-patch, attachment)]

Previous Next

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