implenent stack using queue

qts.coffee

class Queue
  constructor: (@value)->
    @value = @value or []

  enqueue: (what) ->
    @value.push what

  dequeue: ->
    stash = []
    ret = @value[0]
    for i in [0...@value.length - 1]
      stash[i] = @value[i + 1] if @value[i + 1]
    @value = stash
    ret

  getLength: ->
    @value.length

class Stack extends Queue
  constructor: (@value) ->
    super([])
  push: (what) ->
    @enqueue what
  pop: ->
    stash = new Queue
    
    for i in [0...@getLength() - 1]
      stash.enqueue @dequeue()

    @value = stash.value