======Synopsis:======
$__bindctl__(FUNCTION <function> <action> [<args]>) \\ 
$__bindctl__(SEQUENCE <sequence> <action> [<args]>) \\ 
$__bindctl__(MAP [<sequence>] [<action>])

The bindctl function is a low level interface to the keybinding system.
A //FUNCTION// is a thing that can be run when you press a key.
A //SEQUENCE// is one or more unicode code points ("characters") that you can type sequentially, which cause a //FUNCTION// to be executed when you type them.
A //MAP// is a collection of SEQUENCES that begin with a common sub-sequence. 
The client comes with a variety of built-in //FUNCTION//s, and you can create your own.

=====How to work with your own FUNCTION=====
In each case, the first argument is the name of your function ("keybinding") and the second 
argument is what you want to do with that keybinding.  All operations return 1 for success
and 0 or the empty string for failure, unless they say otherwise.

Create a new keybinding that will run the //statement// when it is invoked.

    $bindctl(FUNCTION name CREATE statement)

Destroy a keybinding you created with $bindctl().  You cannot destroy built-in keybindings.

    $bindctl(FUNCTION name DESTROY)

Test whether a keybinding exists -- returns 1 for yes, 0 for no.

    $bindctl(FUNCTION name EXISTS)

Return the keybinding's action.  If you created it with $bindctl(), it will return the statement
you originally provided.  If it is a built-in keybinding, it will return something like "Internal <address>"

    $bindctl(FUNCTION name GET)

Return the names of all keybindings whose names begin with //string// (ie, command-completion)

    $bindctl(FUNCTION string MATCH)

Return the names of all keybindings that match the //pattern// (which can contain wildcards)

    $bindctl(FUNCTION pattern PMATCH)

Return the package associated with the keybinding

    $bindctl(FUNCTION name GETPACKAGE)

Set the package associated with the keybinding

    $bindctl(FUNCTION name SETPACKAGE)


=====How to work with SEQUENCES=====
Bind the sequence "chars" to the given //FUNCTION//.  Naturally, the //FUNCTION// must exist before you can bind anything to it.  The //args// will be passed into the //FUNCTION// as $*.   This is the same operation as /BIND chars function args.  Most //function//s don't take an arg.  The special //function// "NOTHING" will remove the binding.

    $bindctl(SEQUENCE chars SET function args)

Return the //FUNCTION// that is bound to the sequence //chars//.  If the chars are not bound to a sequence, it will return the empty string (which means "nothing")

    $bindctl(SEQUENCE chars GET)

Set the package associated with the sequence //chars//.

    $bindctl(SEQUENCE chars SETPACKAGE)

Get the package associated with the sequence //chars//.

    $bindctl(SEQUENCE chars GETPACKAGE)


=====How to work with MAPs====
Delete all keybindings that begin with //chars//.  Be careful!

    $bindctl(MAP chars CLEAR)

======Real Example:======
Create a keybinding named "GREETINGS" that outputs "Hi there!"
    $bindctl(FUNCTION GREETINGS {echo Hi there!})

Bind Escape-g so it runs your new keybinding
    $bindctl(SEQUENCE ^[g GREETINGS)

Stop all this silliness
    $bindctl(SEQUENCE ^[g NOTHING)