RE: [External] : Re: Concern about new binding.

[Drew Adams]

> > If there are _several_ keys that you can bind
> > keymaps to, then that offers more possibilities
> > than if there is only _one_ key that you can
> > bind a keymap to.
> 
> I'm not sure I see what you mean.  It's not _one_ key.  Having a
> complete keymap at the disposal of third-party libraries means
> that there are (at least) 26 letters free; each of them can be
> bound to a separate keymap.

Yes, of course.  I already acknowledged that.

That's still much less than what can be bound
to several such prefix keys.

_Of course_ you can bind each letter to a
prefix key.  But you can do the same on any of
the still-free keys.  And there are more than
one of those.  (More than one is, well, more
than one.)

What's more, if you put everything on only a
single prefix key, then that leads to deeper
(i.e., longer) key bindings.

For example, I use `C-x x' as a prefix key for
Bookmark+ keys other than specific kinds of
bookmark jumping.  I use `C-x j' and `C-x 4 j'
as prefix keys for bookmark jumping commands.
Without being able to use more than one prefix
key, the jump commands would all be a level
deeper (longer key sequences).

And the jump prefix keys themselves already
have multiple levels of prefix keys.  E.g.,
`C-x j t . % +' jumps to a file bookmark in
the current dir (`.') that has a tag (`t')
that matches a given regexp (`%') you're
prompted for.  Those keys are systematic and
mnemonic, but that's already several prefix
keys deep.

I've seen no reason, so far, why we should
limit 3rd-party libraries to a single prefix
key - even if one can of course keep extending
a prefix key by adding deeper layers.

Better to have _several_ free keys for
3rd-party libraries than to have only one.
That's the point.

No argument for how you can put lots of stuff
on a single prefix key can overcome the fact
that more prefix keys give you more than does
one prefix key.

https://www.emacswiki.org/emacs/BookmarkPlus#BookmarkPrefixKeys