import ast
def process(node):
  #ast.diag(node)
  sliceRegister = ast.nextPRegister()
  ast.outputInBlock( "%s = new %s" % ( sliceRegister, "PySlice" ) )
  
  localLower = ""
  localUpper = ""
  
  if node.upper == None:
    if node.lower == None:
      pass
    else:
      localLower = ast.evaluate(node.lower)
      ast.outputInBlock( "%s.init(%s)" % ( sliceRegister, localLower ) ) 
  elif node.lower == None:
    lowerTypeRegister = ast.nextIRegister()
    localLower = ast.nextPRegister()
    ast.outputInBlock( "%s = 0" % ( localLower ) )
    localUpper = ast.evaluate(node.upper)
    ast.outputInBlock( "%s.init(%s,%s)" % ( sliceRegister, localLower, localUpper ) ) 
  else:
    localLower = ast.evaluate(node.lower)
    localUpper = ast.evaluate(node.upper)
    ast.outputInBlock( "%s.init(%s,%s)" % ( sliceRegister, localLower, localUpper ) ) 

  newListRegister = ast.nextPRegister()
  ast.outputInBlock( "%s = %s[%s]" % ( newListRegister, ast.evaluate(node.expr), sliceRegister ) ) 
  return newListRegister