Re: Emacs completion matches selection UI

[Juri Linkov]

> The main issue is then to figure out how/when to switch to this
> new mode.  E.g. when the user hits `up' right after the *Completions*
> buffer got displayed/updated?

It seems `up' is the most intuitive key to switch to the
*Completions* buffer.  This is how auto-completion works
in web browsers - typing `down' switches from the text field
to the selection list where up/down moves between candidates.
Moving back from the first candidate switches back from the
selection list to the text entry field.  In the minibuffer this
would mean `up' switching to the *Completions* buffer whereas
`down' at the bottom of the *Completions* buffer switching back
to the minibuffer.

The bigger problem is in which order to sort completion candidates.
When navigating from the minibuffer to the *Completions* buffer
`up' should select the first candidate which is more natural to put
at the bottom of the *Completions* buffer sorted in reverse order.

OTOH, to navigate in the forward order from top to bottom
the *Completions* buffer could be displayed below the minibuffer
if this is possible.