Module type Contravariant.WITH_CONTRAMAP

The minimum definition of a Contravariant. It is by using the combinators of this module that the other combinators will be derived.

type 'a t

The type held by the Contravariant Functor.

val contramap : ('a -> 'b) -> 'b t -> 'a t

Mapping over from 'a to 'b over 'b t to 'a t.