So.. any improvements RPN-wise ???

[Didier Lachieze]

1) UNDO: Shift Ans will recall to the stack the last function arguments

2) The ability to interactively expand a list (like EVAL or LIST->)
The following program assigned to a user key (here Shift 9) will do it for the list on the stack level 1. You'll need to press Enter.

Code:

KEY KS_9()
BEGIN
 IF Entry==2 THEN
  RETURN ΣLIST(EXECON("STRING(&1)+\" \"",Ans(1)));
 ELSE
  RETURN -2;
 END;
END;

Note that the RPN stack is limited to 128 levels.