From: Drew Adams <drew.adams@oracle.com>
To: Tassilo Horn <tsdh@gnu.org>
Cc: Michael Heerdegen <michael_heerdegen@web.de>, help-gnu-emacs@gnu.org
Subject: RE: `looking-back' strange warning
Date: Fri, 2 Oct 2015 14:35:03 -0700 (PDT) [thread overview]
Message-ID: <785d8be4-1024-4635-83ff-7bc51dd4b5bf@default> (raw)
In-Reply-To: <87lhblrnpe.fsf@gnu.org>
> This version is about 6 times faster in the t case and a still a bit
> faster in the nil case where the char before point is already different
> (which is the best case for your function).
>
> (defun chars-before (chars)
> "Return non-nil if the literal string CHARS is right before point.
> This is more efficient that `looking-back' for this use case."
> (let ((beg (- (point) (length chars))))
> (unless (< beg 0)
> (save-excursion
> (goto-char beg)
> (looking-at (regexp-quote chars))))))
OK. Good to know.
See also bug #17284,
http://debbugs.gnu.org/cgi/bugreport.cgi?bug=17284,
where this has been discussed and I and others proposed
code for this.
You are welcome to contribute to that (short) bug thread,
or to otherwise try to get such a function added to Emacs.
next prev parent reply other threads:[~2015-10-02 21:35 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-30 8:25 `looking-back' strange warning Andreas Röhler
2015-10-01 6:20 ` Michael Heerdegen
2015-10-01 6:25 ` Tassilo Horn
2015-10-01 6:50 ` Dmitry Gutov
2015-10-01 7:49 ` Andreas Röhler
2015-10-01 8:20 ` Tassilo Horn
2015-10-01 8:46 ` Andreas Röhler
2015-10-01 9:29 ` Tassilo Horn
2015-10-02 0:10 ` Stefan Monnier
2015-10-02 15:21 ` Tassilo Horn
2015-10-01 16:00 ` Drew Adams
2015-10-01 17:56 ` Dmitry Gutov
2015-10-01 18:24 ` Andreas Röhler
2015-10-01 18:59 ` Dmitry Gutov
2015-10-01 19:55 ` Andreas Röhler
2015-10-01 20:26 ` Dmitry Gutov
2015-10-02 0:15 ` Stefan Monnier
2015-10-02 1:18 ` Michael Heerdegen
2015-10-02 5:13 ` Drew Adams
2015-10-02 20:28 ` Drew Adams
2015-10-02 20:59 ` Tassilo Horn
2015-10-02 21:35 ` Drew Adams [this message]
2015-10-03 6:26 ` Tassilo Horn
2015-10-03 6:45 ` Andreas Röhler
2015-10-03 15:20 ` Drew Adams
2015-10-03 15:17 ` Drew Adams
2015-10-02 1:19 ` Michael Heerdegen
2015-10-02 5:12 ` Drew Adams
2015-10-02 6:16 ` Andreas Röhler
2015-10-02 6:36 ` Michael Heerdegen
2015-10-02 12:46 ` Stefan Monnier
2015-10-02 15:02 ` Drew Adams
2015-10-02 19:08 ` Tom Tromey
2015-10-02 19:33 ` Stefan Monnier
2015-10-03 18:11 ` Stefan Monnier
[not found] ` <mailman.176.1443721449.16064.help-gnu-emacs@gnu.org>
2015-10-01 18:50 ` Barry Margolin
[not found] ` <<barmar-D40496.14502501102015@88-209-239-213.giganet.hu>
2015-10-01 23:42 ` Drew Adams
2015-10-02 0:12 ` Stefan Monnier
2015-10-02 5:10 ` Drew Adams
2015-10-02 12:48 ` Stefan Monnier
2015-10-02 15:03 ` Drew Adams
2015-10-02 15:21 ` Stefan Monnier
2015-10-02 15:24 ` Drew Adams
2015-10-02 19:28 ` Stefan Monnier
2015-10-01 12:35 ` Artur Malabarba
[not found] <<560B9C7F.2060301@easy-emacs.de>
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