StoneMasonKarel

/*
 * File: StoneMasonKarel.java
 * --------------------------
 * Karel builds and or repairs columns.
 */

import stanford.karel.*;

public class StoneMasonKarel extends SuperKarel {
        public void run (){
                while (frontIsClear()) {
                        buildColumn () ;
                        moveToNextColumn () ;
                }
                buildColumn () ;
        }

 /* The Karel buildColumn function turns left, then depending upon whether Karel's
  * front is clear and a beeper is present Karel places a beeper if there
  * isn't already one. If there is already a beeper present Karel moves
  * forward 1 space. If Karel's front is blocked and no beepers are present
  *  Karel puts a beeper there. Karel then repositions.
  */

        private void buildColumn () {
                turnLeft () ;
                while (frontIsClear()) {
                        if (noBeepersPresent()) {
                                putBeeper () ;
                        } else {
                                move () ;
                        }
                }
                if (frontIsBlocked()) {
                        if (noBeepersPresent()) {
                                putBeeper () ;
                        }
                        repositionKarel () ;
                }
        }

  /* The repositionKarel function checks if the front is blocked, turns around
   * if it is. Then if the front is clear Karel moves forward but if the front
   * isn't clear Karel turns left.
   *
   */

        private void repositionKarel () {
                turnAround () ;
                while (frontIsClear()) {
                        move () ;
                }
                        turnLeft () ;

        }

        private void moveToNextColumn () {
                for (int i=0; i<4;i++) {
                        move () ;
                }
        }
}