bug#73234: 30.0.91; completion-preview-mode doesn't trigger for case-insensitive capf

[Eshel Yaron via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

Hi,

Morgan Willcock <morgan@ice9.digital> writes:

> Eshel Yaron <me@eshelyaron.com> writes:
>
>>> I've been trying to think of a way to get it to work without disturbing
>>> the user interface that already exists.  Maybe it would be possible
>>> fixup the result in a post-insertion hook if one existed - such a hook
>>> might be generally useful anyway.
>>
>> We have the :exit-function (which your capf can provide as an extra
>> property alongside the completion table it returns), and indeed you
>> could use that to "fix" the case of your prefix after completing it.
>
> I don't think it is the responsibility of the completion function
> because it is not the completion function that is modifying the buffer.
>>
>> That's an interesting solution, I think.  Or do you have some other kind
>> of hook in mind?
>
> Just a hook that runs after it was completion-preview-mode that inserted
> a completion.

I'm quite not sure what you mean by responsibility, but in terms of
functionality, :exit-function is the existing interface for doing
something after a completion is inserted, and Completion Preview mode
supports this interface.

If :exit-function doesn't work for your use case, please explain why,
and if there's indeed a need for another hook, it's easy to add one :)


Thanks,

Eshel