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From: Stefan Kangas <stefankangas@gmail.com>
To: "Mattias Engdegård" <mattiase@acm.org>,
	"Shigeru Fukaya" <shigeru.fukaya@gmail.com>
Cc: 44861@debbugs.gnu.org
Subject: bug#44861: 27.1; [PATCH] signal in `replace-regexp-in-string'
Date: Wed, 25 Nov 2020 16:39:10 -0500	[thread overview]
Message-ID: <CADwFkm=59cqfUCPZNUCvoWv-M-9Jdosq-jQvY7X6MCWKiYGy_Q@mail.gmail.com> (raw)
In-Reply-To: <97535AF5-D542-4267-A5A9-1483C32A61AC@acm.org>

Mattias Engdegård <mattiase@acm.org> writes:

> It is basically your patch but slightly optimised; it turned out that
> the function call and allocation overhead of the original patch made
> it a tad too expensive (a pity, because it was very neat). Now
> performance is about the same as before when the pattern contains no
> submatches, and slightly above (< 10% slower) with one submatch. It
> seems worth the correctness.

Presumably this hasn't worked correctly for a long time, if ever.  Is
that correct?

I personally worry about the performance here.  Since we use regexps
heavily all over, it is not clear (to me) that 10 % overall performance
drop with subexpressions is worth it to work correctly in these rare
edge-cases.  I suppose we do have to fix the bug here, but is it
feasible to solve this in a way that has less performance impact?





  reply	other threads:[~2020-11-25 21:39 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-25  4:02 bug#44861: 27.1; [PATCH] signal in `replace-regexp-in-string' Shigeru Fukaya
2020-11-25 10:58 ` Mattias Engdegård
2020-11-25 14:58   ` Mattias Engdegård
2020-11-25 21:39     ` Stefan Kangas [this message]
2020-11-26 12:57       ` Mattias Engdegård
2020-11-26 13:12         ` Lars Ingebrigtsen
2020-11-26 13:39           ` Mattias Engdegård
2020-11-26 14:03             ` Lars Ingebrigtsen
2020-11-26 14:54               ` Mattias Engdegård
2020-11-29 13:28               ` Basil L. Contovounesios
2020-11-26 13:43           ` Stefan Kangas
2020-11-26 14:03             ` Lars Ingebrigtsen
2020-11-26 14:41             ` Eli Zaretskii

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