From: Tim Landscheidt <tim@tim-landscheidt.de>
To: help-gnu-emacs@gnu.org
Subject: Re: does emacs regular expression support (?!expression)
Date: Thu, 02 Feb 2012 22:17:04 +0000 [thread overview]
Message-ID: <m3lioklw2n.fsf@passepartout.tim-landscheidt.de> (raw)
In-Reply-To: m3pqdwlwc0.fsf@passepartout.tim-landscheidt.de
I wrote:
>> [...]
>>>> matches "foo19" or "bar23", but doesn't capture foo or bar, so that
>>>> (match-string 1) is the number.
>>> In Perl, "(?!pattern)" is a zero-width negative look-ahead
>>> assertion. Emacs does not support these AFAIK.
>> I see. So when you do /foo(?!bar)/ in Perl, you'd need to do
>> "foo\\(?:[^b][^a][^r]\\)" in elisp.
> You have to account for possible end-of-buffer as well so
> usually it's "easier" to use two matches ('(while (and
> (search-forward-regexp "foo") (not (looking-at "bar"))))'
> (untested)) - [...]
Eh, yes, there is an "(untested)", but still the logic is
obviously plain wrong. But you get the idea.
Tim
next prev parent reply other threads:[~2012-02-02 22:17 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-02 14:02 does emacs regular expression support (?!expression) 土星五号
2012-02-02 18:56 ` Tassilo Horn
2012-02-02 21:14 ` Tim Landscheidt
2012-02-02 21:45 ` Tassilo Horn
2012-02-02 22:11 ` Tim Landscheidt
2012-02-02 22:17 ` Tim Landscheidt [this message]
2012-02-03 0:37 ` Kevin Rodgers
2012-02-03 2:12 ` 土星五号
2012-02-03 8:30 ` Thien-Thi Nguyen
2012-02-03 11:17 ` Tim Landscheidt
2012-02-03 11:48 ` Thien-Thi Nguyen
2012-02-04 10:12 ` Tim Landscheidt
2012-02-04 12:16 ` 土星五号
2012-02-04 15:26 ` Thien-Thi Nguyen
2012-02-05 11:57 ` Tim Landscheidt
2012-02-02 22:09 ` Glenn Morris
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