Re: Emacs completion matches selection UI

[Stefan Monnier]

> ;; It is difficult to know when to exit completion-in-region-mode (i.e. hide
> ;; the *Completions*).
[...]
> If there was a special popup to show a list of items, [...], it would
> abstract these difficulties and cut some nasty code out of
> minibuffer.el.

No, it wouldn't.  The problem needs to be solved either way.
`company-mode' solves this problem not by popping up a special GUI
element, but by defining which operations can be performed while this
element is displayed, and which operations cause the element
to disappear.  And completion-in-region-mode does the same, tho using
the *Completions* buffer rather than a special GUI element, and making
different choices about which operations can be performed while the
completions are displayed and which operations make the
completions disappear.

> For the UI case of "I'm in the minibuffer and want to complete
> something" I would rather wait for the general list popup to be
> available with `widget-choose' than add the special down/up keybindings
> that we discussed.

Again, this has nothing to do with whether the list is displayed in
a *Completions* buffer or on a shoestring.  The questions are "when
should the list be displayed", and after that, "when should we enter the
special mode where the user can navigate in this list".
For company-mode, the second question is answered by "immediately" and
the first is answered by "after typing the first N chars of a completion
candidate" (IIRC).

> I think the change is too risky for the short time we have this week.

I'm not sure which change you're thinking of, but I probably agree.


        Stefan