641 B
641 B
Natural Transformation Examples (3/4)
toMaybe :: [a] -> Maybe a
toMaybe [] = Nothing
toMaybe (x:xs) = Just x
toMaybe
is a natural transformation.
It is also a morphism from []
to Maybe
in the Category of \(\Hask\) endofunctors.
![natural transformation commutative diagram](/yogsototh/category-theory-presentation/media/commit/60135c86970a5ad0117afe51396bf7d9ff43a54c/categories/30_How/200_Monads/categories/img/mp/nattrans-list-maybe.png)
![natural transformation commutative diagram](/yogsototh/category-theory-presentation/media/commit/60135c86970a5ad0117afe51396bf7d9ff43a54c/categories/30_How/200_Monads/categories/img/mp/list-maybe-endofunctor-morphism.png)