Eshel Yaron <me@eshelyaron.com> writes:

> Philip Kaludercic <philipk@posteo.net> writes:
>
>> Mauro Aranda <maurooaranda@gmail.com> writes:
>>
>>>
>>> I haven't watch this thread closely, but do note that creating dynamic
>>> choices is quite possible, if I understand correctly what you're looking
>>> for.
>>>
>>> If you can, take a look at the defcustom of completion-styles, in
>>> minibuffer.el.  Its type uses a choice with a specialized
>>> :convert-widget function to keep the choices up-to date.
>>
>> This might be exactly what we are looking for.  It should be possible to
>> adapt `completion--update-styles-options' pretty much directly to our
>> example.
>
> Mauro, thanks for the great tip.  As Philip said, this seems to be
> exactly what we need here.  Accordingly, I'm attaching an updated patch for the
> `defcustom` types (the two other patches from my previous message are
> not affected and remain applicable).

I have slightly modified it to remove the helper functions.  As
mentioned before.  Hope you are fine with it: