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From: Stefan Monnier <monnier@iro.umontreal.ca>
To: "積丹尼 Dan Jacobson" <jidanni@jidanni.org>
Cc: 39595@debbugs.gnu.org, "Mattias Engdegård" <mattiase@acm.org>,
	"Paul Pogonyshev" <pogonyshev@gmail.com>
Subject: bug#39595: #39595: M-x compile still very line-length weak
Date: Sat, 15 Feb 2020 08:57:19 -0500	[thread overview]
Message-ID: <jwvpneg6jlh.fsf-monnier+emacs@gnu.org> (raw)
In-Reply-To: <87h7zs1vvy.5.fsf@jidanni.org> ("積丹尼 Dan Jacobson"'s message of "Sat, 15 Feb 2020 09:28:49 +0800")

> 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






  reply	other threads:[~2020-02-15 13:57 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-13  5:51 bug#39595: M-x compile still very line-length weak 積丹尼 Dan Jacobson
2020-02-14 11:18 ` bug#39595: #39595: " Mattias Engdegård
2020-02-14 16:27   ` Mattias Engdegård
2020-02-14 17:00     ` Eli Zaretskii
2020-02-14 22:47       ` Mattias Engdegård
2020-02-15  7:35         ` Eli Zaretskii
2020-02-15 16:45           ` Mattias Engdegård
2020-02-16 12:15             ` Mattias Engdegård
2020-02-15  1:28 ` 積丹尼 Dan Jacobson
2020-02-15 13:57   ` Stefan Monnier [this message]
2020-02-16 15:37 ` 積丹尼 Dan Jacobson
2020-02-17 11:07   ` Mattias Engdegård

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