GNU bug report logs - #39595
M-x compile still very line-length weak

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Package: emacs;

Reported by: 積丹尼 Dan Jacobson <jidanni <at> jidanni.org>

Date: Fri, 14 Feb 2020 02:47:02 UTC

Severity: minor

Done: Mattias Engdegård <mattiase <at> acm.org>

Bug is archived. No further changes may be made.

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Message #26 received at 39595 <at> debbugs.gnu.org (full text, mbox):

From: Stefan Monnier <monnier <at> iro.umontreal.ca>
To: 積丹尼 Dan Jacobson <jidanni <at> jidanni.org>
Cc: 39595 <at> debbugs.gnu.org,
 Mattias Engdegård <mattiase <at> acm.org>,
 Eli Zaretskii <eliz <at> gnu.org>, Paul Pogonyshev <pogonyshev <at> gmail.com>
Subject: Re: #39595: M-x compile still very line-length weak
Date: Sat, 15 Feb 2020 08:57:19 -0500
> Anyway I recall perl is fast on regexps, newlines or not.

That's just a reputation.
In reality, maybe its constant is lower than that of Emacs's regexp
matcher, and maybe it implements a few more optimisations, but it
suffers from the same explosion as Emacs's regexp matcher with regexps
like the one under discussions (i.e. when Emacs's regexps are slow,
it's because of the basty complexity introduced by backtracking and
Perl's regexps do backtracking more or less as much as Emacs's).


        Stefan





This bug report was last modified 5 years and 99 days ago.

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