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bug#51368: 29.0.50; `cl-case' should error on incorrect use
From: |
Lars Ingebrigtsen |
Subject: |
bug#51368: 29.0.50; `cl-case' should error on incorrect use |
Date: |
Sun, 24 Oct 2021 19:48:54 +0200 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/29.0.50 (gnu/linux) |
Philipp Stephani <p.stephani2@gmail.com> writes:
> This form demonstrates a few incorrect uses of `cl-case':
>
> (cl-case a
> (nil 0) ; doesn't match anything
> (t 1) ; matches everything, but too early
> ('foo 2)) ; matches `quote' in addition to `foo'
>
> It would be nice if `cl-case' would signal an error or at least warn
> about these at macroexpansion time, since they are somewhat subtle and
> easy to get wrong.
An error from the second case would be nice, and a warning on the first
case, but the third case:
(macroexpand
'(cl-case a
('foo (message "foo"))))
=> (cond ((cl-member a ''foo) (message "foo")))
and
(equal ''foo (list 'quote 'foo))
which, sure, whatever. But I guess the question is whether we can
actually warn about that, because to the reader, the two forms are
equivalent?
--
(domestic pets only, the antidote for overdose, milk.)
bloggy blog: http://lars.ingebrigtsen.no