Re: [PATCH] `completing-read`: Add `group-function` support to completion metadata

[Dmitry Gutov]

On 26.04.2021 02:33, Stefan Monnier wrote:
> > So it's better if at least icomplete-mode is enabled, preferably with an
> > option which shows the completions right away with no input. And the
> > vertical style should be even better.
>
> Maybe we could accommodate this in the default UI by adding an option to
> eagerly popup the *Completions* buffer (and keep it updated as long as
> it's displayed) and to keep it disabled by default but make it possible
> to enable it via completion-category-(overrides|defaults).

I don't know if it's enough. And I have my doubts (expressed previously 
already) about a *Completions* buffer that is impossible to dismiss: it 
might hide a window showing a buffer you care about.

Ultimately, it can be a good change/feature, but it should be championed 
by somebody actually willing to use the resulting UI on a regular basis.

My ideal UI would probably be more like this: 
https://emacs-lsp.github.io/lsp-ui/images/lsp-xref.gif (though perhaps 
with a slightly different layout). Meaning, a posframe popup showing the 
list of all locations, vertically, and a preview popup by its side or 
below it, displaying the current selected location.

Ivy should be easy enough to extend to do that, I think. *Completions* - 
not so much.