Write a robot simulator.
A robot factory's test facility needs a program to verify robot movements.
The robots have three possible movements:
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.
This exercise does require some kind of global state for your robot. In erlang this can be done in various ways (starting with most idiomatic one):
gen_*
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