GNU bug report logs - #43100
28.0.50; pcase not binding variables conditionally

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Message #8 received at 43100 <at> debbugs.gnu.org (full text, mbox):

From: Philipp Stephani <p.stephani2 <at> gmail.com>
To: Pip Cet <pipcet <at> gmail.com>
Cc: 43100 <at> debbugs.gnu.org, Stefan Monnier <monnier <at> iro.umontreal.ca>
Subject: Re: bug#43100: 28.0.50; pcase not binding variables conditionally
Date: Sat, 29 Aug 2020 14:01:45 +0200

Am Sa., 29. Aug. 2020 um 11:42 Uhr schrieb Pip Cet <pipcet <at> gmail.com>:
>
> I'm having trouble with pcase's behavior.
>
> (pcase "a"
>   ((or (pred symbolp) name)
>    (let ((foo 'bar)) name)))
>
> throws an error. It shouldn't.

Isn't this case documented in the manual? The last section of
https://www.gnu.org/software/emacs/manual/html_node/elisp/pcase-Macro.html
states:
"It makes no sense for each sub-pattern [in an `or' sequence] to
let-bind a different set of symbols because the body forms have no way
to distinguish which sub-pattern matched and choose among the
different sets."

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