The Haskell Unfolder Episode 35: distributive and representable functors

An explanation of the Distributive and Representable type classes in Haskell and how they can be used to model grids.

We're going to look at two somewhat more exotic type classes in the Haskell library ecosystem: Distributive and Representable. The former allows you to distribute one functor over another, the latter provides you with a notion of an index to access the elements. As an example, we'll return once more to the grids used in Episodes 32 and 33 to describe the tic-tac-toe game, and we'll see how some operations we used can be made more elegant in terms of these type classes. This episode is, however, self-contained; having seen the previous episodes is not required.