From: Tassilo Horn <tassilo@member.fsf.org>
To: help-gnu-emacs@gnu.org
Subject: Re: does emacs regular expression support (?!expression)
Date: Thu, 02 Feb 2012 22:45:04 +0100 [thread overview]
Message-ID: <87ipjo52qn.fsf@thinkpad.tsdh.de> (raw)
In-Reply-To: m31uqdlyyn.fsf@passepartout.tim-landscheidt.de
Tim Landscheidt <tim@tim-landscheidt.de> writes:
Hi Tim,
>> It would be more helpful if you'd tell us what (?!expression) would
>> match, preferably with some examples. Syntactically, emacs regexp's shy
>> groups look similar. The regular expression
>
>> "\\(:?foo\\|bar\\)\\([0-9]+\\)"
BTW, that should have been (?:...).
>> 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.
Bye,
Tassilo
next prev parent reply other threads:[~2012-02-02 21:45 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 [this message]
2012-02-02 22:11 ` Tim Landscheidt
2012-02-02 22:17 ` Tim Landscheidt
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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