\ Stack--pushdown data structure built on top of a List              vandys
only extensions definitions

List -> subclass: Stack

Stack -> :method push ( elem self -- )   -> add method;
Stack -> :method peek ( self -- elem )   dup List>nelem @
   dup 0= abort" empty"   1- cells swap List>elems @ + @ method;
Stack -> :method pop ( self -- elem )   dup -> peek
   swap List>nelem dec method;
Stack -> :method do ( arg 'fn self -- )   super-> reverseDo method;

Stack -> :method reverseDo ( arg 'fn self -- )   super-> do method;

                                                                     vandys


Class Stack--a LIFO data structure

:method Stack:push The stack grows and shrinks from the tail of the List
:method Stack:peek Return element on top of stack

:method Stack:pop

:method Stack:do Because of this, we have to create the illusion that the
 tail is "first" when iterating for display or otherwise
:method Stack:reverseDo If "do" is reversed, then so must "reverseDo" be...