RE: [External] : Re: Current mode command discovery

[Drew Adams]

> There are times when a menu entry should be hidden
> and times where it should be grayed out (inactive).
> Likewise, a command

Stop right there.  Exactly that.  Sometimes we
want to _show_ a menu item or submenu, but dim
it, to show that it's available and can be
enabled in some contexts.

We annotate command names in *Completions* with
their key bindings for exactly this kind of purpose.
We don't just change `M-x' so it will no longer
show commands that aren't (or are) bound to keys.
Why would we?

Except that this is about filtering _completion_
candidates, not just filtering the commands you
can invoke currently.

We let you filter completion candidates by
typing text to match.  Why wouldn't we also let
you filter candidates also by hitting particular
keys that filter particular classes of candidates
(in this case, commands).

As for dimming a menu item that's not currently
enabled - same here: you might well want to see
all command names in *Completions*, but have some
highlighted or dimmed so you know they can't
be invoked in the current mode (for one example).

Let users control which candidates get displayed.
Let them include commands that make no sense in
the current mode.  But let them filter those out,
or sort them last, or show them dimmed, or...

We should be increasing, not decreasing, user
control over the current set of candidates.