RE: feature/completions-highlight-modifications e3c5b99 3/6: Add completions-highlight-mode initial implementation.

[Drew Adams <drew.adams@oracle.com>]

> Sorry, I was not clear enough: I meant that the new feature doesn't
> allow in the minibuffer using the same navigation keys that are
> already available in the *Completions* buffer, e.g. <PgDown> and <PgUp>
> typed in the *Completions* buffer scroll it up and down.
> 
> For example, while in the minibuffer type 'TAB' that displays a very
> long list of completions, then type 'C-M-v', and see how it scrolls the
> *Completions* buffer.  Better yet try typing <M-PgDown> and <M-PgUp>
> in the minibuffer, and see how it scrolls the *Completions* buffer
> up and down.  I meant that a new feature could allow such page
> scrolling without the 'M-' modifier, by just using <PgDown> and <PgUp>
> in the minibuffer (and C-v/M-v as well) to scroll the *Completions* buffer.

(By <PgDown> and <PgUp> I assume you really mean
the logical keys <next> and <prior>.)

I hope that you don't choose keys such as <next>
and <prior> for this.  Or <home> and <end>.

Such pairs are useful for other things.  Icicles
uses those two pairs of keys for cycling different
kinds of matches, for instance.

> (and C-v/M-v as well)

And I especially hope we don't assign _multiple_
pairs for this scrolling.  Icicles uses `C-v' and
`M-v' for it.  Aren't those two keys sufficient?
Why multiply things, here, reducing key binding
possibilities for other purposes?
___

Yes, I know that Emacs binds both pairs, C-v/M-v
and next/prior, in general.  But that was done
long ago, when keys were not so precious.  I'd
prefer that `next' and `prior' were left free of
any default key bindings.

I feel the same about C-e/C-b and end/home, FWIW.

I know that many applications outside Emacs use
end/home and next/prior for movement.  But I don't
think it's great that Emacs does that by default.

I do feel differently about C-n/C-p and down/up.
But I think that users outside Emacs are _much_
more likely to expect the arrow keys to move
down/up than they are to have strong expectations
about end/home and next/prior.