Thread return value

Thread return value

[Manuel Giraud via Emacs development discussions.]

Hi,

Is there a way to retrieve an Emacs thread's implicit return value?  In
the simple example below, it would be to get the boolean value computed
by the thread 'my-flip' after its death:

--8<---------------cut here---------------start------------->8---
(defun coin ()
  (evenp (random 100)))

(setq my-flip (make-thread #'coin))
--8<---------------cut here---------------end--------------->8---

I don't need a solution where I can 'setq' a global variable into
'coin'.  Consider that 'coin' is immutable (or written by someone else
for other purpose).

If this is not currently possible, do you think it would be a hard thing
to do in "thread.el" or "thread.c"?

Best regards,
-- 
Manuel Giraud

Re: Thread return value

[Helmut Eller]

On Sun, Nov 05 2023, Manuel Giraud via "Emacs development discussions." wrote:

> Hi,
>
> Is there a way to retrieve an Emacs thread's implicit return value?

thread-join would probably work.

Helmut

Re: Thread return value

[Manuel Giraud via Emacs development discussions.]

Helmut Eller <eller.helmut@gmail.com> writes:

> On Sun, Nov 05 2023, Manuel Giraud via "Emacs development discussions." wrote:
>
>> Hi,
>>
>> Is there a way to retrieve an Emacs thread's implicit return value?
>
> thread-join would probably work.

Thanks!  It was simple as that 😅.  It was not clear from the elisp info
page.
-- 
Manuel Giraud

Re: Thread return value

[Manuel Giraud via Emacs development discussions.]

Manuel Giraud <manuel@ledu-giraud.fr> writes:

> Thanks!  It was simple as that 😅.  It was not clear from the elisp info
> page.

I guess I should learn to read : "It returns the result of the THREAD function."
-- 
Manuel Giraud

Re: Thread return value

[Eli Zaretskii]

> Date: Sun, 05 Nov 2023 09:57:40 +0100
> From:  Manuel Giraud via "Emacs development discussions." <emacs-devel@gnu.org>
> 
> Is there a way to retrieve an Emacs thread's implicit return value?

Yes, by calling thread-join.