Write a robot simulator.

A robot factory's test facility needs a program to verify robot movements.

The robots have three possible movements:

turn right turn left advance Robots are placed on a hypothetical infinite grid, facing a particular direction (north, east, south, or west) at a set of {x,y} coordinates, e.g., {3,8}, with coordinates increasing to the north and east.

The robot then receives a number of instructions, at which point the testing facility verifies the robot's new position, and in which direction it is pointing.

The letter-string "RAALAL" means: Turn right Advance twice Turn left Advance once Turn left yet again Say a robot starts at {7, 3} facing north. Then running this stream of instructions should leave it at {9, 4} facing west.