module Data.Extensible.Inclusion (
#if __GLASGOW_HASKELL__ >= 800
type (⊆)
#else
(⊆)()
#endif
, Include
, inclusion
, shrink
, spread
, IncludeAssoc
, Associated
, inclusionAssoc
, shrinkAssoc
, spreadAssoc
) where
import Data.Extensible.Class
import Data.Extensible.Product
import Data.Extensible.Sum
import Data.Extensible.Internal
import Data.Extensible.Internal.Rig
type xs ⊆ ys = Include ys xs
type Include ys = Forall (Member ys)
inclusion :: forall xs ys. Include ys xs => Membership ys :* xs
inclusion = htabulateFor (Proxy :: Proxy (Member ys)) (const membership)
shrink :: (xs ⊆ ys) => h :* ys -> h :* xs
shrink h = hmap (hindex h) inclusion
spread :: (xs ⊆ ys) => h :| xs -> h :| ys
spread (EmbedAt i h) = views (pieceAt i) EmbedAt inclusion h
class Associated xs t where
getAssociation :: Membership xs t
instance Associate k v xs => Associated xs (k ':> v) where
getAssociation = association
type IncludeAssoc ys = Forall (Associated ys)
inclusionAssoc :: forall xs ys. IncludeAssoc ys xs => Membership ys :* xs
inclusionAssoc = htabulateFor (Proxy :: Proxy (Associated ys)) (const getAssociation)
shrinkAssoc :: (IncludeAssoc ys xs) => h :* ys -> h :* xs
shrinkAssoc h = hmap (hindex h) inclusionAssoc
spreadAssoc :: (IncludeAssoc ys xs) => h :| xs -> h :| ys
spreadAssoc (EmbedAt i h) = views (pieceAt i) EmbedAt inclusionAssoc h