Consistent argument naming

Here's a thought.

_trap = function( v ) { ... }

Should we always use 'v'?

eg you'll typically find:
_focused = function( f ) { ... }
_selected = function( s ) { ... }

If v was _always_ used then maybe it would add to the readability of the
code.  The only issue you'd have would be with:

_trap1 = function( v ) {
    _trap2 = function( w ) { ... }
}

In which case you could use 'w' as you get deeper, and 'x' if you go one
deeper and so on.

Is this a good or bad idea?

- Charlie