Safe Haskell | Safe |
---|---|

Language | Haskell2010 |

# Documentation

class (forall a. Covariant (t a)) => Divariant (t :: * -> * -> *) where Source #

When providing a new instance, you should ensure it satisfies the two laws: * Identity: dimap identity identity ≡ identity * Composition: dimap (f . g) (h . i) ≡ dimap g h . dimap f i