On Sun, Dec 4, 2022, 16:54 Stefan Monnier <monnier@iro.umontreal.ca> wrote:

There's one I can think of: SLY, because there external tool's
> completion code can be tweaked to fit the needs of Emacs :-)
>
> For most others it's probably difficult, indeed, which is why
> I suggested to make it optional (unless you know how the tool
> does its matching in which case you may be able to re-use
> `completion-pcm--merge-try` or to implement something similar).
>

Yup, this rhymes exactly with what I wrote in the docstring in the latest
version.  I understand how it could be used now. Another question is if I
as SLY author would use it. I don't think so, to be honest, seems to much
hassle for not a lot of benefit. But others may want to, of course.

> Else, I think we end up contacting the external tool one too many times
> for
> > the same PATTERN. That's at least with the popular completion front-ends
> > such as fido/vertico who probably go for the 'allc' immediately.
>
> The default UI uses either tryc (when you hit TAB) or allc (when you
> ask the see *Completions*) not both.


Yes and eventually if you hit TAB twice that's two requests. So we need
caching. But that's fine, I've implemented that already. Have a look at the
latest commit when you find the time.

João