Re: (declare (type (function...

[Tomas Hlavaty <tom@logand.com>]

On Tue 07 May 2024 at 13:55, Marco Antoniotti <marco.antoniotti@unimib.it> wrote:
> IMHO (and, I am not afraid to say, of many common lispers) this is
> shortsighted and a rather gratuitous departure from what CL does.  With
> some potential unintended consequences down the road.

There was a discussion about this.

id:yp15xyf88yb.fsf@fencepost.gnu.org
Andrea Corallo <acorallo@gnu.org> (February 23) ()
Subject: Declaring Lisp function types
To: emacs-devel@gnu.org
Date: Fri, 23 Feb 2024 11:02:52 -0500

also

id:jwv4jdne65n.fsf-monnier+emacs@gnu.org
Stefan Monnier <monnier@iro.umontreal.ca> (March 03) ()
Subject: Re: Declaring Lisp function types
To: Andrea Corallo <acorallo@gnu.org>
Cc: "Stefan Monnier via Emacs development discussions." <emacs-devel@gnu.org>
Date: Sun, 03 Mar 2024 09:52:23 -0500
[...]
Then I'd go with
(declare (type (function ..)))
[...]

> (defun foo (x)
>     *(declare (signature (function (integer) float))*
>     (+ x 42.0))

grep signature ~/mr/emacs would yield lots of false positives

function-signature or something like that would be better name.
but this was also discussed already.