680 B
680 B
Natural Transformation Examples (1/4)
data Tree a = Empty | Node a [Tree a]
toTree :: [a] -> Tree a
toTree [] = Empty
toTree (x:xs) = Node x [toTree xs]
toTree
is a natural transformation.
It is also a morphism from []
to Tree
in the Category of \(\Hask\) endofunctors.