class BasicBlock:
   # Uninterrupted sequence of instructions.
   def __init__(self, name):
      self.name = name
      self.instructions = []
   def __repr__(self):
      return 'BasicBlock {0}'.format(self.name)
   def addInstruction(self, i):
      i.parent = self
      self.instructions.append(i)
   addIns = addInstruction
   def replaceInstruction(self, i1, i2):
      idx = self.instructions.index(i1)
      i1.parent = None
      i2.parent = self
      self.instructions[idx] = i2
   def removeInstruction(self, i):
      i.parent = None
      self.instructions.remove(i)
   def getInstructions(self):
      return self.instructions
   Instructions = property(getInstructions)
   def getLastIns(self):
      return self.instructions[-1]
   LastIns = property(getLastIns)
   @property
   def Empty(self):
      return len(self.instructions) == 0
   @property
   def FirstInstruction(self):
      return self.instructions[0]
   FirstIns = FirstInstruction
   def getSuccessors(self):
      if not self.Empty:
         i = self.LastIns
         return i.Targets
      return []
   Successors = property(getSuccessors)