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From: Stefan Monnier <monnier@IRO.UMontreal.CA>
To: Helmut Eller <eller.helmut@gmail.com>
Cc: 16567@debbugs.gnu.org
Subject: bug#16567: 24.3.50; pcase should signal an error if no case matches
Date: Mon, 08 Sep 2014 15:19:06 -0400	[thread overview]
Message-ID: <jwvegvmorgt.fsf-monnier+emacsbugs@gnu.org> (raw)
In-Reply-To: <m2ha8pzsn5.fsf@gmail.com> (Helmut Eller's message of "Mon, 27 Jan 2014 10:22:06 +0100")

> pcase returns nil for this example:
>  (pcase 3
>    (1 1)
>    (2 2))
> it would be more useful if it would signal an error instead.  Manually
> adding a "catch-all case" and inventing some error message is tedious
> and it's also easy to forget.

The "nil default" is also very handy at times and pcase has been in use
for long enough that we can't really change this easily.

But we could add a new pcase-exhaustive macro that does that.


        Stefan





  parent reply	other threads:[~2014-09-08 19:19 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-01-27  9:22 bug#16567: 24.3.50; pcase should signal an error if no case matches Helmut Eller
2014-01-27 10:27 ` Daimrod
2014-01-27 11:56   ` Helmut Eller
2014-01-27 12:23     ` Daimrod
2014-09-08 18:27 ` Leo Liu
2014-09-08 19:19 ` Stefan Monnier [this message]
2014-09-08 20:58   ` Helmut Eller
2014-09-09  0:41     ` Stefan Monnier
2014-09-10  0:02       ` Leo Liu
2014-09-10  2:26         ` Stefan Monnier
2014-09-10  2:52           ` Leo Liu
2014-09-10  5:32             ` Josh
2014-09-10  6:18               ` Helmut Eller
2014-09-10 13:17             ` Stefan Monnier
2014-09-10 14:28               ` Helmut Eller
2014-09-10 17:26                 ` Stefan Monnier
2014-09-10 14:33               ` Leo Liu
2014-09-10 16:54               ` Glenn Morris
2014-09-10 17:54                 ` Stefan Monnier
2014-09-12  2:35                   ` Leo Liu
2014-09-12 17:15                     ` Stefan Monnier
2014-09-13  0:29                       ` Leo Liu
2014-09-13  3:10                         ` Stefan Monnier
2014-09-13  4:57                           ` Leo Liu
2014-09-13 15:01                             ` Stefan Monnier
2014-09-13 17:25                               ` Leo Liu
2014-09-10 17:39               ` Richard Stallman

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