public class DequeueTest
{
  public static void main(String[] args)
  {
    char command = ' ';
    String str;
    Dequeue1 deq = new Dequeue1();
    while (command != 'q') {
      System.out.print("Command (q, h (enqueue onto head), H (remove from head),\n"
           + "         t (enqueue onto tail), T (remove from tail), p (print)): ");
      command = Keyboard.readChar();

      switch (command) {
        case 'q':
          break;

        case 'h':
          System.out.print("String: ");
          str = Keyboard.readString();
          deq.addAtHead(str);
          break;

        case 'H':
          str = deq.removeHead();
          if (str != null)
            System.out.println("Removed: " + str);
          else
            System.out.println("Tried to remove item from empty dequeue");
          break;

        case 't':
          System.out.print("String: ");
          str = Keyboard.readString();
          deq.addAtTail(str);
          break;

        case 'T':
          str = deq.removeTail();
          if (str != null)
            System.out.println("Removed: " + str);
          else
            System.out.println("Tried to remove item from empty dequeue");
          break;

        case 'p':
          deq.print("", "\n");
          break;

        default:
          System.out.println("Huh?  Try again");
          break;
      }
    }
  }
}