Re: unwind-protect within while-no-input

[Dmitry Gutov <dmitry@gutov.dev>]

Hi Daniel,

It's good to see you in this thread.

On 12/05/2024 01:08, Daniel Mendler wrote:

>>> Is cape-wrap-noninterruptible from the cape package helpful?
>> It should help, but it would be odd if any non-trivial completion function would
>> need to use cape to function inside corfu-mode reliably.
> cape-wrap-noninterruptible and similarly cape-wrap-silent and
> cape-wrap-purify are meant as stop gap measures, used to wrap non-robust
> Capfs, until they are improved. There are multiple Capfs in the wild
> which regularly print messages or throw unexpected errors. For example,
> pcomplete-completions-at-point even modified the buffer until Emacs 29,
> which could be mitigated with cape-wrap-purify.

How would such a capf (that has to use cape-wrap-noninterruptible) 
usually be improved?

What's your recommendation regarding the necessary cleanup inside the 
while-no-input block?

Michael's suggestion --

(let (foo)
   (while-no-input
     (unwind-protect (while t nil)
       (let ((inhibit-quit t))
         (sleep-for 10)
         (setq foo 'interrupted)
         (message "foo: %s" foo)))
     (message "foo: %s" foo)))

-- seems to work. Meaning that the interpreter doesn't quit at the 
beginning of the unwind block (right before 'let') even when some 
pending input exists. But is that a reliable way to write this logic, 
i.e. one that both works on all supported platforms and is likely to 
survive the potential future optimizations in the Elisp VM?