@hackage countable1.1

class Countable, for countable types . * class AtLeastOneCountable, for countable types that have at least one value . * class InfiniteCountable, for infinite countable types . * class Searchable, for types that can be searched over. This turns out to include some infinite types, see http://math.andrej.com/2007/09/28/seemingly-impossible-functional-programs/. . * class Finite, for finite types . * class Singular, for singular (n = 1) types . * class Empty, for empty (n = 0) types . * data Nothing, an empty type . Some orphan instances: . * (Searchable a,Eq b) => Eq (a -> b) . * (Finite t) => Foldable ((->) t) . * (Finite a) => Traversable ((->) a) . * (Show a,Finite a,Show b) => Show (a -> b)