From: pjb@informatimago.com (Pascal J. Bourguignon)
To: help-gnu-emacs@gnu.org
Subject: Re: Help with regexp
Date: Wed, 02 Dec 2009 15:16:49 +0100 [thread overview]
Message-ID: <87ljhlmpf2.fsf@galatea.local> (raw)
In-Reply-To: mailman.12029.1259760724.2239.help-gnu-emacs@gnu.org
Andreas Politz <politza@fh-trier.de> writes:
> harven <harven@free.fr> writes:
>
>> Andreas Politz <politza@fh-trier.de> writes:
>>
>>
>>> Things I (won't) miss most:
>>>
>>> - extreme backslasheritis
>>> - no short aliases for important constructs :
>>> digits,symbol-constituents,newline,space
>>
>> ??
>
> I should have defined short as a synonym for a 2-character sequence.
> The main idea here is conciseness.
>>
>> \sw word constituent. Same as \w.
>> \s_ symbol constituent.
>
> I guess I was involved with vim for a to long time, where \w matches chars in a
> c identifier, my bad.
>
>> \s- whitespace character. Same as [[:space:]]
>>
>> See the wiki for the full list
>> http://www.emacswiki.org/emacs-en/RegularExpression
>>
>> In a string you can use \n to match a newline, \t to match a tab.
>> That's the reason why you have to use \\ to match a backslash.
>>
> But I can't enter a constant string in the mini-buffer...
Of course you can:
(defun test (string)
(interactive "sPlease enter a string: ")
(insert string))
>> Count the number of lines in the region
>> M-x my-perl RET print $. if eof RET
>
> That maybe a good workaround, thanks.
It would be nicer to just implement the new regexp syntax in emacs
lisp, translating to the old regexp syntax.
> I guess my main complain would be the over-expressiveness. Be it in the
> actual regexp, due to backslashes and most atoms being 3-5 characters
> in length. Or in the replacement, due to missing zero-width matches.
But in any case, it would be better to use sexps to build regexps:
(seq "=>" (rep (comp ":"))
(alt ""
(seq ":" (rep (comp ":"))
(alt ""
(seq ":" (rep (comp ":"))
(alt ""
(seq ":" (rep (comp ":")))))))))
--> "=>\\([^:]\\)*\\(\\|:\\([^:]\\)*\\(\\|:\\([^:]\\)*\\(\\|:\\([^:]\\)*\\)\\)\\)"
(defun seq (&rest seq) (apply (function concat) seq))
(defun rep (&rest seq) (format "\\(%s\\)*" (apply (function concat) seq)))
(defun alt (alt &rest rest)
(with-output-to-string
(princ "\\(")
(princ alt)
(dolist (alt rest)
(princ "\\|")
(princ alt))
(princ "\\)")))
(defun comp (&rest chars) (format "[^%s]" (apply (function concat) chars)))
--
__Pascal Bourguignon__
next prev parent reply other threads:[~2009-12-02 14:16 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <mailman.11978.1259698881.2239.help-gnu-emacs@gnu.org>
2009-12-01 21:07 ` Help with regexp Pascal J. Bourguignon
2009-12-02 5:16 ` tomas
2009-12-02 6:03 ` Andreas Politz
2009-12-02 7:11 ` tomas
2009-12-02 8:14 ` Andreas Politz
2009-12-05 6:46 ` tomas
2009-12-02 7:18 ` suvayu ali
[not found] ` <mailman.12000.1259733814.2239.help-gnu-emacs@gnu.org>
2009-12-02 9:41 ` harven
2009-12-02 13:31 ` Andreas Politz
2009-12-02 16:05 ` Lennart Borgman
2009-12-02 16:56 ` Andreas Politz
2009-12-02 17:16 ` Lennart Borgman
[not found] ` <mailman.12039.1259774199.2239.help-gnu-emacs@gnu.org>
2009-12-02 20:00 ` harven
2009-12-02 17:01 ` Andreas Politz
[not found] ` <mailman.12029.1259760724.2239.help-gnu-emacs@gnu.org>
2009-12-02 14:16 ` Pascal J. Bourguignon [this message]
2009-12-02 6:36 ` Xavier Maillard
[not found] ` <mailman.12002.1259735748.2239.help-gnu-emacs@gnu.org>
2009-12-02 11:16 ` Pascal J. Bourguignon
[not found] ` <mailman.11999.1259731365.2239.help-gnu-emacs@gnu.org>
2009-12-03 3:48 ` Stefan Monnier
2009-12-02 15:37 ` Colin S. Miller
2009-12-01 20:21 Xavier Maillard
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