From: Stefan Monnier <monnier@iro.umontreal.ca>
To: Lars Ingebrigtsen <larsi@gnus.org>
Cc: emacs-devel@gnu.org
Subject: Re: Make regexp handling more regular
Date: Thu, 03 Dec 2020 10:10:06 -0500 [thread overview]
Message-ID: <jwvmtyvj5o0.fsf-monnier+emacs@gnu.org> (raw)
In-Reply-To: <87blfbz3lu.fsf@gnus.org> (Lars Ingebrigtsen's message of "Thu, 03 Dec 2020 09:38:21 +0100")
> Off-list, it's been pointed out that the current implementation of
> functions like re-search-forward would be faster than these interfaces
> because they produce less garbage -- since there's just one global match
> object, it's static, while
Yes, it's indeed my main worry.
Reusing the match-data sounds like a good practical approach.
Maybe another approach would be to use an API where the match doesn't
return a "match data" but instead let-binds some variables with the
relevant data. IOW, specify right away in which part of the data you're
interested, so only the relevant data is returned. That would also
remove the need for the `string-match-p` alternatives which don't return
any match data.
I'm not completely sure what it would look like, tho. Maybe
(let-re-match (overall (beg end)) (re-match "regexp")
...)
which would be equivalent to
(progn
(re-match "regexp")
(let ((overall (match-string 0))
(beg (match-beginning 1))
(end (match-end 1)))
...))
??
This has problems dealing with match-failure tho: it works, but it with
a lot of spurious match-data extraction.
Stefan
next prev parent reply other threads:[~2020-12-03 15:10 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-02 9:05 Make regexp handling more regular Lars Ingebrigtsen
2020-12-02 10:44 ` Lars Ingebrigtsen
2020-12-02 11:12 ` Stefan Kangas
2020-12-02 11:21 ` Philipp Stephani
2020-12-03 8:31 ` Lars Ingebrigtsen
2020-12-02 17:17 ` Stefan Monnier
2020-12-02 17:45 ` Yuan Fu
2020-12-02 19:24 ` Stefan Monnier
2020-12-03 8:40 ` Lars Ingebrigtsen
2020-12-03 8:38 ` Lars Ingebrigtsen
2020-12-03 15:10 ` Stefan Monnier [this message]
2020-12-03 16:58 ` Lars Ingebrigtsen
2020-12-03 17:40 ` Stefan Monnier
2020-12-02 21:19 ` Juri Linkov
2020-12-03 8:41 ` Lars Ingebrigtsen
2020-12-03 15:00 ` Stefan Monnier
2020-12-03 21:02 ` Juri Linkov
2020-12-03 22:20 ` Vasilij Schneidermann
2020-12-02 21:28 ` Daniel Martín
2020-12-03 4:16 ` Adam Porter
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