michael rice wrote:
Here's a function from Data.Tree:
unfoldTree :: (b -> (a, [b])) -> b -> Tree a
Build a tree from a seed value
Could someone please give me a brief example of usage.
In as far as understanding it, it may be easier if you look at the
generalized version of the anamorphism:
newtype Fix f = Fix { unFix :: f (Fix f) }
type Tree a = Fix (Node a)
data Node a b = Node a [b]
instance Functor (Node a) where
fmap f (Node a bs) = Node a (map f bs)
unfoldTree f = Fix . fmap (unfoldTree f) . f
--
Live well,
~wren
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