{-# LANGUAGE TemplateHaskell, MultiParamTypeClasses, FlexibleInstances,
UndecidableInstances, TypeOperators, Rank2Types #-}
module Data.Comp.Param.Multi.Desugar where
import Data.Comp.Param.Multi
class (HDifunctor f, HDifunctor g) => Desugar f g where
desugHom :: Hom f g
desugHom = desugHom' . hfmap Hole
desugHom' :: f a (Cxt h g a b) :-> Cxt h g a b
desugHom' x = appCxt (desugHom x)
instance (Desugar f h, Desugar g h) => Desugar (f :+: g) h where
desugHom = caseHD desugHom desugHom
desugar :: Desugar f g => Term f :-> Term g
desugar (Term t) = Term (appHom desugHom t)
desugarA :: (HDifunctor f', HDifunctor g', DistAnn f p f', DistAnn g p g',
Desugar f g) => Term f' :-> Term g'
desugarA (Term t) = Term (appHom (propAnn desugHom) t)
instance {-# OVERLAPPABLE #-} (HDifunctor f, HDifunctor g, f :<: g) => Desugar f g where
desugHom = simpCxt . inj