newRPL: Interactive stack

[Han]

Shift keys have traditionally been used for navigation. What about using alpha for selection instead? What I am imagining is that there is some sort of curser indication the currently focused stack level.

arrows = move cursor
Left shift + up/down = move cursor page up/down
Right shift + up/down = move cursor to top/bottom of stack
alpha = select object in currents stack level; holding alpha allows multiple selection while moving keys up/down (allows for alpha lock + shift keys, too, so we could select pages of items)

left = copy selection to current position
right = move selection to current position
right shift + left = move selection to top of stack
right shift + right = move selection to bottom of stack
left shift + left = roll up within selection (basically nothing if only single selection; otherwise selected items treated as if they were within their own substack)
left shift + right = roll down within selection (similar to above)

left (no selection) = swap current position w/ level above cursor
right (no selection) = swap current position w/ level below cursor
*left shift + left (no selection) = from cursor to top of stack is a substack; rotates up
*left shift + right (no selection) = from cursor to top of stack is a substack; rotates down
right shift + left (no selection) = move item at cursor to top of stack
right shift + right (no selection) = move item at cursor to bottom of stack

There's really no reason to actually drag an item by "holding" it. This would require the screen be updated continually -- which could be bad if the object is "large" or the selected group takes up the entire screen. How would we know where the new position is without referencing the objects at those levels? By only moving a cursor, and leaving the selected object in place, we can better see where we want to move/copy the objects. It also means the drawing routines for stack manipulation are much simpler (you only update after an actual move/copy as opposed to updating every step up/down).

* regular roll up/down operates on stack levels 1 up to the cursor; left shift allows for roll up/down but with the "upper" part of the stack (from cursor to top)

(gotta run an errand; will edit and add more)