From: Marcin Borkowski <mbork@mbork.pl>
To: Stefan Monnier <monnier@iro.umontreal.ca>
Cc: help-gnu-emacs@gnu.org
Subject: Re: Performance of `re-search-backward' vs `re-search-forward'
Date: Mon, 12 Apr 2021 21:39:54 +0200 [thread overview]
Message-ID: <8735vvb8c5.fsf@mbork.pl> (raw)
In-Reply-To: <jwvsg3vczb4.fsf-monnier+emacs@gnu.org>
On 2021-04-12, at 17:13, Stefan Monnier <monnier@iro.umontreal.ca> wrote:
>> I seem to (very vaguely) remember reading that `re-search-backward' is
>> significantly slower than `re-search-forward'. However, I can't find
>> anything about it in the docstring (nor in the Elisp reference) now. Am
>> I even correct?
>
> I haven't looked at the code recently so my memory might be off, but
> I can't think of any reason why it should be noticeably slower, no.
So both basically move character by character and check if the regex
matches there (more or less)?
> Maybe you're confusing it with `looking-back` which is much slower than
> `looking-at`?
Yes, that was it! Thanks!
Best,
--
Marcin Borkowski
http://mbork.pl
next prev parent reply other threads:[~2021-04-12 19:39 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-12 5:38 Performance of `re-search-backward' vs `re-search-forward' Marcin Borkowski
2021-04-12 15:13 ` Stefan Monnier
2021-04-12 19:39 ` Marcin Borkowski [this message]
2021-04-12 20:40 ` [External] : " Drew Adams
2021-04-12 21:03 ` Stefan Monnier
2021-04-12 20:59 ` Stefan Monnier
2021-04-13 6:07 ` Marcin Borkowski
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