[RP] nested keymaps

[Shawn Betts]

Hi folks,

So I've thought about Dan's nested keymap patch and how I'd like to
see it done. I came up with this idea (it's implemented, I just have
to check it in).

4 functions:
newkmap <keymap>  - Create a new keymap
delkmap <keymap>  - delete a keymap
prefix <keymap>   - read a key and execute the command associated with it in 
KEYMAP

and

definekey <keymap> <key> <command>    - bind KEY to COMMAND in the keymap, 
KEYMAP.

so for instance, to hang all the frame splitting and whatnot off the
C-t s, you'd do:

newkmap frame
definekey frame r resize
definekey frame apostrophe fselect
...
bind f prefix frame

and if you wanted to hang a keymap off C-t s j

you'd add:

newkmap wackymap
definekey wackymap t echo foobar
definekey frame j prefix wackymap

So, hitting C-t s j t would show foobar in the message bar.

What do you guys think?

There are some deficiencies:

* you can get mutually recursively nest keymaps. Sorta weird, but you
  just have to hit an unbound key to exit the loop.

definekey wackymap t prefix frame

C-t s j t j t j t j t j ...

* It'd be nice to display the full line of keys if a key is unbound:

C-t s j t g unbound key

instead of just

g unbound key

This can be done..I just haven't done it yet.

* The help screen is not really super great

help now takes a keymap and displays the keys on that map. It'd be
nice to write some scripts or something to print emacs style key
listings...

I think this fits with the theme of ratpoison more than Dan's
patch. But it might be a bit weird for people. I'm still excited about
the sneakiness of it, so maybe when that wears off I'll think
otherwise :).

Shawn