#
# This file contains the Python code from Program 6.8 of
# "Data Structures and Algorithms
# with Object-Oriented Design Patterns in Python"
# by Bruno R. Preiss.
#
# Copyright (c) 2003 by Bruno R. Preiss, P.Eng.  All rights reserved.
#
# http://www.brpreiss.com/books/opus7/programs/pgm06_08.txt
#
class StackAsLinkedList(Stack):

    def accept(self, visitor):
        assert isinstance(visitor, Visitor)
        ptr = self._list.head
        while ptr is not None:
            visitor.visit(ptr.datum)
            if visitor.isDone:
                return
            ptr = ptr.next

    # ...