Robots; introductory examples

Here are some short programs that demonstrate how you can add robots to a world.

Adding a robot

Robots have more characteristics than a block or a beeper and must be created before they are added. You create a robot with one instruction: 

   Robot ringo = new Robot();
And you add it to the world with another (assumng the world is called space): 
   space.add(ringo);
This adds the robot to cell(0, 0).

The following program shows this.

Example

Ringo.java 
//
// Add a robot to a world

public class Ringo
{
   public static void main(String [] args)
   {
      World stage = new World();

      Robot ringo = new Robot();
      stage.add(ringo);
   }
}

Notice that the robot is in cell(0, 0) and is facing east. (It looks like an arrow head pointing in the direction that it is facing.)

Moving a robot

Now that ringo's on the stage, what can he do? Well he can move. Simply call ringo's move method; the instruction looks like 

   ringo.move();
This instruction will move the robot one square forward. Execute this instruction every time you move.
Note: This time you see a run and a step button. These instructions let you control the rate of the robot's instructions. When the robot has finished his instructions, the "finished" message appears.

Dancer.java 
//
// Let's dance!

public class Dancer
{
   public static void main(String [] args)
   {
      World stage = new World();

      Robot ringo = new Robot();
      stage.add(ringo);

      // once ringo's been added
      // to the stage, he can move
      ringo.move();
      ringo.move();
      ringo.move();
   }
}

A turn for the better

Of course ringo would be quite constrained if he couldn't change direction. Robot's can turn using the instruction 

   ringo.turnLeft();
which turns the robot left.

Explorer.java 
public class Explorer
{
   public static void main(String [] args)
   {
      World stage = new World();

      Robot ringo = new Robot();
      stage.add(ringo);

      ringo.move();
      ringo.move();
      ringo.move();

      ringo.turnLeft();

      ringo.move();
      ringo.move();

      ringo.turnLeft();
      ringo.turnLeft();

      ringo.move();
   }
}