-- parent script "Stack"

property _tos

on push (me, data)
  me._tos = [#data:data, #next:me._tos]
end

on pop (me)
  if voidP(me._tos) then return VOID
  data = me._tos.data
  me._tos = me._tos.next
  return data
end

on peek (me)
  if voidP(me._tos) then return VOID
  return me._tos.data
end

on empty (me)
  return voidP(me.peek())
end