text: # -*- coding: utf-8 -*-
  
  # Copyright 2017 IBM RESEARCH. All Rights Reserved.
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  #     http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  # =============================================================================
  
  """
  Node for an OPENQASM CNOT statement.
  
  Author: Jim Challenger
  """
  from ._node import Node
  
  
  class Cnot(Node):
      """Node for an OPENQASM CNOT statement.
  
      children[0], children[1] are id nodes if CX is inside a gate body,
      otherwise they are primary nodes.
      """
  
      def __init__(self, children):
          """Create the cnot node."""
          Node.__init__(self, 'cnot', children, None)
  
      def qasm(self):
          """Return the corresponding OPENQASM string."""
          return "CX " + self.children[0].qasm() + "," + \
                 self.children[1].qasm() + ";"
  