text: /*
   * Copyright 2018 Google LLC
   *
   * 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.
   */
  
  
  
  #ifndef MACHINE_H
  #define MACHINE_H
  
  enum class HeadPos { Here, Left, Right };
  
  struct Turing {
    unsigned char r1 : 6;
    unsigned char r2 : 6;
    unsigned char ctr : 6;
    unsigned char eip : 6;
  };
  
  struct Tile {
    Turing turing;  // 24 bits
    unsigned char value : 6;
    HeadPos head;  // 2 bits
  };
  
  #endif
  