#11011: Add type-indexed type representations (`TypeRep a`) -------------------------------------+------------------------------------- Reporter: bjmprice | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by bgamari): An alternative to falling back to an entirely unindexed `TyCon` would be to augment it with a type-indexed version, {{{#!hs -- Metadata describing a type constructor. Same thing we currently have. data TyCon = TyCon { module, package, con_name :: String } -- A type constructor together with the kinds it was applied to (abstract) data TTyCon (a :: k) = TTyCon { tycon :: TyCon, dep_kinds :: [TypeRep], kind :: TTypeRep k } -- A type representation (abstract) data TTypeRep (a :: k) where TrTyCon :: Fingerprint -> TyCon a -> TTypeRep a TrApp :: forall k1 k2 (a :: k1 -> k2) (b :: k1). Fingerprint -> TTypeRep a -> TTypeRep b -> TTypeRep (a b) pattern TRApp :: forall k k1 (a :: k1 -> k) (b :: k1). TTypeRep a -> TTypeRep b -> TTypeRep (a b) pattern TRCon :: forall k (a :: k). TTyCon a -> TTypeRep a tyConDepKinds :: TTyCon a -> [TypeRep] tyConKind :: TTyCon (a :: k) -> TTypeRep k }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11011#comment:18 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler