Re: Declaring Lisp function types

[Eli Zaretskii <eliz@gnu.org>]

> Date: Sun, 25 Feb 2024 17:04:30 +0000
> Cc: emacs-devel@gnu.org
> From: Alan Mackenzie <acm@muc.de>
> 
> On Fri, Feb 23, 2024 at 11:02:52 -0500, Andrea Corallo wrote:
> > Hi all,
> 
> > I'm looking into moving out the function type declarations in
> > 'comp-known-type-specifiers' in order to move them to where the function
> > are actually defined.  This to easy maintenance (ATM they get out of
> > sync) and to allow the user for (indeed optionally) declaring function
> > types.
> 
> > In principle I believe we are interested in expressing the the argument
> > types and (maybe optionally) the return type.
> 
> What's missing is the why.  Do we actually want to put function type
> declarations in Lisp source at all?  They will clutter up the code more
> than it is cluttered up at the moment.

My understanding of the rationale is that then we will be able to
maintain the information about each function in one place, instead of
in two.  Currently, when the signature changes, someone must remember
to go to that other place and update it.

So I think this change is generally for the better, as it will make
maintenance easier and less error-prone.