Alexander Vieth
In many languages a NxN array seems like a good pick. In Haskell, most would translate that into lists of lists. I know I have. However, traversing those lists to get a position, calculate where a piece or agent could go, etc., feels awkward and unefficient. Beside the point already made, we have no type safe guarantee that our 64x64 won't become a 63x63 + 65x1 board due to some misbehaving function.
Perhaps choosing a zipper-like representation, in which all adjacent places on your board can be found without any traversal, would make the usage less awkward and more efficient.
I thought of zippers too, although their simplicity suffers when moving from 1D lists to 2D lists-of-lists. Comonads are possibly related. They're certainly useful for cellular automata[1], which are effectively zero-player board games. [1] http://blog.sigfpe.com/2006/12/evaluating-cellular-automata-is.html Cheers, Chris