GNU bug report logs - #13678
24.2.93; pcase: mention list-like QPatterns in the doc

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Package: emacs;

Reported by: michael_heerdegen <at> web.de

Date: Sun, 10 Feb 2013 17:49:02 UTC

Severity: minor

Found in version 24.2.93

Done: Michael Heerdegen <michael_heerdegen <at> web.de>

Bug is archived. No further changes may be made.

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Message #11 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Michael Heerdegen <michael_heerdegen <at> web.de>
To: bug-gnu-emacs <at> gnu.org
Subject: Re: bug#13678: 24.2.93; pcase: mention list-like QPatterns in the doc
Date: Mon, 11 Feb 2013 14:37:48 +0100

Hi Stefan,

> > Sure, `(QPAT1 . QPAT2)' also matches lists - but `(QPAT1 . QPAT2)' and
> > `(QPat1 ...QPatn)' are different forms (expressions)
>
> Actually, no, they are identical:
>
>   (QPAT1 QPAT2 QPAT3) is indistinguishable from
>   (QPAT1 . (QPAT2 . (QPAT3 . nil)))
>
> the equivalence between the two is imposed by the reader, long before we
> know that these things will be "patterns in a pcase" rather than
> expressions, or data in a quoted thingy, ...

Simply right, thanks.  I wonder, however, if that's clear for every
user.  Nonetheless, there are enough examples in

  (elisp) Pattern matching case statement

that use the (QPAT1 QPAT2 QPAT3) syntax.  So, I'll close this, thanks.


Regards,

Michael.
This bug report was last modified 12 years and 103 days ago.

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