Staggerbot

Moves the robot. A staggerbot selects a random direction and tries to move to the adjacent square in that direction. If there is a wall or another robot in that square, the robot collides with it and does not change squares (as per the moveTowards method of its body, possibly colliding and breaking itself or another robot).

If the staggerbot collides with something, it remains facing whatever it collided with and ends its turn there. In case the staggerbot did not collide with anything, it again selects a new random direction and turns to face that direction (which may or may not be the direction it just moved in).

Note: this means that if (and only if) the staggerbot did not collide, it picks two random directions per turn, one to move in and one to face in.

The staggerbot selects each random direction using the following algorithm:

1. Use an indexed collection containing all the four CompassDir objects in clockwise order, starting with north.

2. Pick a random index. Use the nextInt method in scala.util.Random that produces a pseudorandom integer that is at least zero and lower than the method’s integer parameter.

3. Select the direction found at the random index.

A particular staggerbot always uses the same instance of Random to generate numbers. It does not create a new random number generator every time this method is called. Each staggerbot has its own Random object.

This method assumes that it is called only if the robot is not broken or stuck.

Moves the robot one square forwards, if there is nothing there. If that square isn’t empty, the robot does not move, so this method never causes a collision.

Controls the robot body’s actions for a single turn. If the brain considers the robot to be stuck (see isStuck), this method does nothing. If not stuck, the brain calls its own moveBody method, which carries out the actual robot actions.

Returns the direction this robot is facing in.

Determines whether or not the robot brain considers the robot to be stuck. A brain considers the robot stuck if and only if all the squares surrounding the robot contain unpassable obstacles, as defined by the mayAdvance method. Only the four nearest squares in the main compass directions are considered.

Returns the location of this robot in its robot world.

Returns the coordinates that point at the square that is immediately in front of this robot.

Checks the the square that neighbors this robot in the given direction to see if it contains something that the robot brain considers an obstacle. This method is abstract; different kinds of robot brains will have different definitions of what counts as an obstacle.

This default implementation (which may be overriden by subtypes) does not consider anything to be an obstacle. Robots that rely on this default implementation are willing to move in any direction and never consider themselves to be stuck (see isStuck).

Changes the robot’s name to the given one.

Note to students: In Scala, a method whose name ends in an underscore and an equals sign — like this one’s — can be called using a special syntax. For instance, this method can be called either with the statement bot.name_=("Suzy") or simply with an assignment statement: bot.name = "Suzy". You won’t find many uses for this in O1, but it’s nice to know nonetheless.

Returns the brain of the robot immediately in front of this robot. The brain is returned in an Option wrapper; None is returned if there is no robot in that square or if the robot that is there has no brain.

Returns the square that is immediately in front of this robot.

Returns a textual representation of the robot (which is the robot’s name).

Returns the world that this robot is located in.