/**
* Parses the String returning a TurnInstruction instance or throwing a
* WrongInstructionFormatException()
*
* @param cad text String to parse
* @return Instruction Reference pointing to an instance of a Instruction subclass, if it is
* corresponding to the String cad
* @throws WrongInstructionFormatException When the String is not TURN LEFT or RIGHT or GIRAR LEFT
* or RIGHT
*/
public Instruction parse(String cad) throws WrongInstructionFormatException {
String[] words = cad.split(" ");
int length = words.length;
Rotation rot;
if (length == 2 && (words[0].equalsIgnoreCase("TURN") || words[0].equalsIgnoreCase("GIRAR"))) {
rot = Rotation.parseRotation(words[1]);
if (rot != Rotation.UNKNOWN) return new TurnInstruction(rot);
else throw new WrongInstructionFormatException("Incorrect Format for instruction 'TURN'");
} else throw new WrongInstructionFormatException("Incorrect Format for instruction 'TURN'");
}
/**
* Undo turn instruction, this implies rotate in the opposite direction and restore the energy
* consumed in the rotation.
*/
public void undo() {
navi.rotate(rotation.opposite()); // First, we perform an opposite rotation
robot.addFuel(+5); // Later we restore the energy inverted in the rotation
}