module Rasa.Ext.Views.Internal.BiTree where
import Data.Typeable
import Data.Bifunctor
import Data.Functor.Foldable
data BiTree b l =
Branch b (BiTree b l) (BiTree b l)
| Leaf l
deriving (Show, Typeable, Functor, Traversable, Foldable)
instance Bifunctor BiTree where
bimap _ g (Leaf x) = Leaf (g x)
bimap f g (Branch b l r) = Branch (f b) (bimap f g l) (bimap f g r)
data BiTreeF b l r =
BranchF b r r
| LeafF l
deriving (Show, Functor, Typeable)
type instance Base (BiTree a b) = BiTreeF a b
instance Recursive (BiTree a b) where
project (Leaf x) = LeafF x
project (Branch s l r) = BranchF s l r
instance Corecursive (BiTree a b) where
embed (BranchF sp x xs) = Branch sp x xs
embed (LeafF x) = Leaf x