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

import Pandora.Core.Functor (type (:.), type (:=))
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.Paradigm.Controlflow.Joint.Interpreted (Interpreted (Primary, run))

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

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

instance Pointable t => Liftable (UT Covariant Covariant t) where
        lift x = UT $ point <$> x

instance Extractable t => Lowerable (UT Covariant Covariant t) where
        lower (UT x) = extract <$> x