Re: Drifting towards a statically typed Emacs Lisp. [Was: Introducing 'safety' compilation parameter]

[Andrea Corallo]

Alan Mackenzie <acm@muc.de> writes:

> Hello, Eli.
>
> On Tue, May 07, 2024 at 16:15:47 +0300, Eli Zaretskii wrote:
>> > Date: Tue, 7 May 2024 12:01:33 +0000
>> > Cc: emacs-devel@gnu.org, Eli Zaretskii <eliz@gnu.org>,
>> >   monnier@iro.umontreal.ca, mattias.engdegard@gmail.com,
>> >   stefankangas@gmail.com
>> > From: Alan Mackenzie <acm@muc.de>
>
>> > I see this change as one more boil-the-frog-slowly step towards turning
>> > Emacs Lisp into a statically typed language.
>
>> Alan, please be kinder, even if you dislike very much suggestions of
>> others.
>
> No offence was intended.
>
>> The above could have been easily rephrased as
>
>>   Emacs Lisp should not be turned into a statically typed language.
>
>> without losing any useful content, ....
>
> Not really - what would have been lost is the equivalent  of ".... and I
> see this process happening at the moment.".  The frog metaphor was an
> economical way of phrasing this.  Again, I'm sorry it caused offence.
>
>> .... including your strenuous objection to the change.
>
> I see Emacs Lisp steadily drifting towards being statically typed, and I
> don't think that's a good thing.  As far as I'm aware, there has been no
> general agreement amongst Emacs developers for this (unless it's
> happened as a side-thread in some thread without having an accurate
> Subject:).
>
> We currently have the prospect of lots of functions being cluttered up
> with "type" declarations.  We already have meaningless (to a Lisp
> programmer) things like:
>
>     Inferred type: (function (&optional t t) t)                               
>                                              
>
> appearing in prominent positions in doc strings.  Why?

Because it can be informative (when there are types other than t),
anyway you can control it with 'help-display-function-type' if you don't
want to have it in the *Help* buffer.

> If this is the way Emacs Lisp is to develop, can't we at least have an
> open discussion about it and a positive decision taken, rather than
> letting it "just happen"?  As is already clear, I see static typing in
> Emacs Lisp, except, perhaps, on a very limited scale, as a Bad Thing.

Again, there's no plan to make elisp statically typed.  I agree with you
this is a tool to be used on a limited scale, if this is not clear
enough from the doc now I guess we can just improve it.

  Andrea