bimap package:first-class-families

data Bimap
first-class-families Fcf Fcf.Class.Bifunctor Fcf.Classes
Type-level bimap.

Example

>>> data Example where Ex :: a -> Example  -- Hide the type of examples to avoid brittleness in different GHC versions

>>> :kind! Ex (Eval (Bimap ((+) 1) (Flip (-) 1) '(2, 4)) :: (Natural, Natural))
Ex (Eval (Bimap ((+) 1) (Flip (-) 1) '(2, 4)) :: (Natural, Natural)) :: Example
= Ex '(3, 3)