Re: Declaring Lisp function types

[Tomas Hlavaty <tom@logand.com>]

On Mon 26 Feb 2024 at 11:52, Andrea Corallo <acorallo@gnu.org> wrote:
> ATM we have several function type declarations kept in a different file
> and naturally they get out of sync over time.

What happens when they get out of sync?

> So yes one reason is to move the declarations where functions are
> actually defined.

What happens when they are wrong?

> These declarations are in use by the native compiler in order to help
> generating better code, computing automatically the function signature
> of non type declared functions (signatures which we present in C-h f)

Do you have a specific example?

(describe-function 'car)
and
(describe-function 'sort)
do not show any signature in emacs 28.2

> and (hope in the close future) aid the programmer by performing extra
> error checking at compile time.

How is this different from CL:CHECK-TYPE?
Would CL:CHECK-TYPE be sufficient?
(eww "clhs check-type")
https://www.lispworks.com/documentation/HyperSpec/Body/m_check_.htm