splitNewTyConApp_maybe (FunTy arg res) = Just (funTyCon, [arg,res])
splitNewTyConApp_maybe other = Nothing
--- get instantiated newtype rhs, the arguments had better saturate
--- the constructor
newTyConInstRhs :: TyCon -> [Type] -> Type
newTyConInstRhs tycon tys =
let (tvs, ty) = newTyConRhs tycon in substTyWith tvs tys ty
repType ty | Just ty' <- coreView ty = repType ty'
repType (ForAllTy _ ty) = repType ty
repType (TyConApp tc tys)
- | isClosedNewTyCon tc = -- Recursive newtypes are opaque to coreView
- -- but we must expand them here. Sure to
- -- be saturated because repType is only applied
- -- to types of kind *
- ASSERT( {- isRecursiveTyCon tc && -} tys `lengthIs` tyConArity tc )
- repType (new_type_rep tc tys)
+ | isNewTyCon tc
+ , (tvs, rep_ty) <- newTyConRep tc
+ = -- Recursive newtypes are opaque to coreView
+ -- but we must expand them here. Sure to
+ -- be saturated because repType is only applied
+ -- to types of kind *
+ ASSERT( tys `lengthIs` tyConArity tc )
+ repType (substTyWith tvs tys rep_ty)
+
repType ty = ty
-- repType' aims to be a more thorough version of repType
go ty = ty
--- new_type_rep doesn't ask any questions:
--- it just expands newtype, whether recursive or not
-new_type_rep new_tycon tys = ASSERT( tys `lengthIs` tyConArity new_tycon )
- case newTyConRep new_tycon of
- (tvs, rep_ty) -> substTyWith tvs tys rep_ty
-
-- ToDo: this could be moved to the code generator, using splitTyConApp instead
-- of inspecting the type directly.
typePrimRep :: Type -> PrimRep
-- The reason is that f must have kind *->*, not *->*#, because
-- (we claim) there is no way to constrain f's kind any other
-- way.
-
\end{code}