From: Oliver Scholz <alkibiades@gmx.de>
Subject: Re: rx vs sregex - a "match" to the death
Date: Mon, 06 Oct 2003 09:25:03 +0200 [thread overview]
Message-ID: <uvfr2g75c.fsf@ID-87814.user.dfncis.de> (raw)
In-Reply-To: mailman.1139.1065373803.21628.help-gnu-emacs@gnu.org
Martin Stone Davis <m0davis@pacbell.net> writes:
[...]
> While I was comparing the two functions, I could not find if/how rx
> handles numbered backreferences. It's done in sregex like this:
>
> ;; (sregexq (group (or "Go" "Run"))
> ;; ", Spot, "
> ;; (backref 1)) => "\\(Go\\|Run\\), Spot, \\1"
>
> How do you do the same using rx?
[...]
Well, you could use (regexp "\\1"), but this is of course not
satisfying. I am not aware of any other way to use backrefs with `rx'.
However, I was not aware that you actually can use backrefs within a
regexp. I tried
(progn (looking-at "\\w+")
(forward-char 1)
(re-search-forward "\\0" nil t))
But that did not lead to the result that you would expect if backrefs
are/were supported within regexps.
Could you provide an example where this is meaningful?
Oliver
--
15 Vendémiaire an 212 de la Révolution
Liberté, Egalité, Fraternité!
next prev parent reply other threads:[~2003-10-06 7:25 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <mailman.1134.1065355880.21628.help-gnu-emacs@gnu.org>
2003-10-05 15:45 ` rx vs sregex - a "match" to the death Oliver Scholz
2003-10-05 17:08 ` Martin Stone Davis
[not found] ` <mailman.1139.1065373803.21628.help-gnu-emacs@gnu.org>
2003-10-06 7:25 ` Oliver Scholz [this message]
2003-10-06 8:41 ` Martin Stone Davis
[not found] ` <mailman.1154.1065429721.21628.help-gnu-emacs@gnu.org>
2003-10-06 8:55 ` Oliver Scholz
2003-10-05 12:07 Martin Stone Davis
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