module Pandora.Paradigm.Controlflow.Joint.Schemes.TU (TU (..)) where

import Pandora.Core.Functor (type (:.), type (:=))
import Pandora.Pattern.Category ((.))
import Pandora.Pattern.Functor.Covariant (Covariant ((<$>)))
import Pandora.Pattern.Functor.Pointable (Pointable (point))
import Pandora.Pattern.Functor.Extractable (Extractable (extract))
import Pandora.Pattern.Functor.Divariant (($))
import Pandora.Pattern.Transformer.Liftable (Liftable (lift))
import Pandora.Pattern.Transformer.Lowerable (Lowerable (lower))
import Pandora.Pattern.Transformer.Hoistable (Hoistable (hoist))
import Pandora.Paradigm.Controlflow.Joint.Interpreted (Interpreted (Primary, run))

newtype TU ct cu t u a = TU (t :. u := a)

instance Interpreted (TU ct cu t u) where
	type Primary (TU ct cu t u) a = t :. u := a
	run (TU x) = x

instance Pointable t => Liftable (TU Covariant Covariant t) where
	lift = TU . point

instance Extractable t => Lowerable (TU Covariant Covariant t) where
	lower (TU x) = extract x

instance Covariant t => Hoistable (TU Covariant Covariant t) where
	hoist f (TU x) = TU $ f <$> x