iterator 패턴

iterator를 사용하는 패턴

class Iterator:
  def nextVal(self):
    pass
  def hasNext(self):
    pass
    
class ArryIterator(Iterator):
  def __init__(self,arryContainer):
    self.container = arryContainer.container
    self.pos = -1

  def hasNext(self):
    if self.pos<len(self.container)-1:
      return True
    return False

  def nextVal(self):
    if self.hasNext():
      self.pos += 1
      return self.container[self.pos]    

class ArryRevIterator(Iterator):
  def __init__(self,arryContainer):
    self.container = arryContainer.container
    self.pos = len(self.container)

  def hasNext(self):
    if -1 < self.pos-1:
      return True
    return False

  def nextVal(self):
    if self.hasNext():
      self.pos -= 1
      return self.container[self.pos]    

class ArryContainer:
  def __init__(self):
    self.container = []

  def add(self,num:int):
    self.container.append(num)
  
  def getIterator(self):
    return ArryIterator(self)

  def getRevIterator(self):
    return ArryRevIterator(self)
  
def printByIter(iter):
  while iter.hasNext():
    print(iter.nextVal(),end=' ')
  print(' ')