Re: Emacs completion matches selection UI

[Stefan Monnier]

> OK, is there a way to make a verification and testing plan for this?  If
> there was some automation around completion support, it would certainly
> speed things up, but we need at least a list of currently non-compliant
> modes in Emacs.  How do you look for the exceptions, by searching for
> old functions or testing manually?

The code which does not use minibuffer.el for its completion generally
rolls its own.  Grepping for *Completions* and display-completion-list is
what I've done so far, but I probably missed some.

I don't think it's terribly important to make sure we got 100% of the cases.

> As with company-mode, this can be a frontend choice (affecting
> `display-completion-list', and see below for the suggested
> `display-list' function).  How about a defcustom
> `completion-ui-frontend' with some choices?

The general idea of completion-ui was great, yes.

> For the user, a new defcustom `completion-ui-preferences'?  And for the
> caller, some kind of plist/alist passed to `completion-at-point' that
> merges cleanly with `completion-ui-preferences'?

Could be.  Tho as mentioned before, I'm not sure that there's a need for
caller-provided preferences.

> I would like that, too, so choosing from a list of elements can use all
> the improvements suggested here for `display-completion-list'.

Not sure what you mean by that: minibuffer completion would presumably
use the same completion mechanism as in-buffer completion (as is
already the case, to a large extent), so completing-read would already
use the new mechanisms.

> Could this be a new `display-list' function, used to display both
> completion selection (through `display-completion-list') and
> list selection?

Could be.  I don't know enough in which contexts "list selection" could
be used to know if/how it would make sense.


        Stefan