-class StackUnderflowError < RuntimeError
-end
-
-class StackOverflowError < RuntimeError
-end
-
-class Stack
-
- def initialize
- @items = []
- end
-
- def push object
- raise StackOverflowError if @items.length == 10
- @items.push object
- end
-
- def pop
- raise StackUnderflowError if @items.empty?
- @items.delete @items.last
- end
-
- def peek
- raise StackUnderflowError if @items.empty?
- @items.last
- end
-
- def empty?
- @items.empty?
- end
-
- def full?
- @items.length == 10
- end
-
-end