%
+% (c) The University of Glasgow 2006
% (c) The GRASP/AQUA Project, Glasgow University, 1998
%
-\section[Type]{Type - public interface}
+Type - public interface
\begin{code}
module Type (
-- Kinds
Kind, SimpleKind, KindVar,
- kindFunResult, splitKindFunTys,
+ kindFunResult, splitKindFunTys, splitKindFunTysN,
liftedTypeKindTyCon, openTypeKindTyCon, unliftedTypeKindTyCon,
argTypeKindTyCon, ubxTupleKindTyCon,
isLiftedTypeKind, isUnliftedTypeKind, isOpenTypeKind,
isUbxTupleKind, isArgTypeKind, isKind, isTySuperKind,
- isCoSuperKind, isSuperKind, isCoercionKind,
+ isCoSuperKind, isSuperKind, isCoercionKind, isEqPred,
mkArrowKind, mkArrowKinds,
isSubArgTypeKind, isSubOpenTypeKind, isSubKind, defaultKind, eqKind,
import TypeRep
-- friends:
-import Var ( Var, TyVar, tyVarKind, tyVarName,
- setTyVarName, setTyVarKind )
+import Var
import VarEnv
import VarSet
-import OccName ( tidyOccName )
-import Name ( NamedThing(..), tidyNameOcc )
-import Class ( Class, classTyCon )
-import PrelNames( openTypeKindTyConKey, unliftedTypeKindTyConKey,
- ubxTupleKindTyConKey, argTypeKindTyConKey )
-import TyCon ( TyCon, isRecursiveTyCon, isPrimTyCon,
- isUnboxedTupleTyCon, isUnLiftedTyCon,
- isFunTyCon, isNewTyCon, newTyConRep, newTyConRhs,
- isAlgTyCon, tyConArity, isSuperKindTyCon,
- tcExpandTyCon_maybe, coreExpandTyCon_maybe,
- tyConKind, PrimRep(..), tyConPrimRep, tyConUnique,
- isCoercionTyCon_maybe, isCoercionTyCon
- )
+import OccName
+import Name
+import Class
+import PrelNames
+import TyCon
-- others
-import StaticFlags ( opt_DictsStrict )
-import Util ( mapAccumL, seqList, lengthIs, snocView, thenCmp, isEqual, all2 )
+import StaticFlags
+import Util
import Outputable
-import UniqSet ( sizeUniqSet ) -- Should come via VarSet
-import Maybe ( isJust )
+import UniqSet
+
+import Data.Maybe ( isJust )
\end{code}
-- By being non-recursive and inlined, this case analysis gets efficiently
-- joined onto the case analysis that the caller is already doing
coreView (NoteTy _ ty) = Just ty
-coreView (PredTy p) = Just (predTypeRep p)
+coreView (PredTy p)
+ | isEqPred p = Nothing
+ | otherwise = Just (predTypeRep p)
coreView (TyConApp tc tys) | Just (tenv, rhs, tys') <- coreExpandTyCon_maybe tc tys
= Just (mkAppTys (substTy (mkTopTvSubst tenv) rhs) tys')
-- Its important to use mkAppTys, rather than (foldl AppTy),
\begin{code}
mkFunTy :: Type -> Type -> Type
+mkFunTy (PredTy (EqPred ty1 ty2)) res = mkForAllTy (mkWildCoVar (PredTy (EqPred ty1 ty2))) res
mkFunTy arg res = FunTy arg res
mkFunTys :: [Type] -> Type -> Type
-mkFunTys tys ty = foldr FunTy ty tys
+mkFunTys tys ty = foldr mkFunTy ty tys
isFunTy :: Type -> Bool
isFunTy ty = isJust (splitFunTy_maybe ty)
(b) synonyms
(c) predicates
(d) usage annotations
- (e) all newtypes, including recursive ones
+ (e) all newtypes, including recursive ones, but not newtype families
It's useful in the back end.
\begin{code}
repType ty | Just ty' <- coreView ty = repType ty'
repType (ForAllTy _ ty) = repType ty
repType (TyConApp tc tys)
- | isNewTyCon tc = -- Recursive newtypes are opaque to coreView
+ | 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 *
predTypeRep (ClassP clas tys) = mkTyConApp (classTyCon clas) tys
-- Result might be a newtype application, but the consumer will
-- look through that too if necessary
+predTypeRep (EqPred ty1 ty2) = pprPanic "predTypeRep" (ppr (EqPred ty1 ty2))
\end{code}
-- Only applied to types of kind *, hence the newtype is always saturated
splitRecNewType_maybe ty | Just ty' <- coreView ty = splitRecNewType_maybe ty'
splitRecNewType_maybe (TyConApp tc tys)
- | isNewTyCon tc
+ | isClosedNewTyCon tc
= ASSERT( tys `lengthIs` tyConArity tc ) -- splitRecNewType_maybe only be applied
-- to *types* (of kind *)
ASSERT( isRecursiveTyCon tc ) -- Guaranteed by coreView
-- This comparison is used exclusively (I think) for the
-- finite map built in TcSimplify
cmpPredX env (ClassP c1 tys1) (ClassP c2 tys2) = (c1 `compare` c2) `thenCmp` cmpTypesX env tys1 tys2
-cmpPredX env (IParam _ _) (ClassP _ _) = LT
-cmpPredX env (ClassP _ _) (IParam _ _) = GT
+cmpPredX env (EqPred ty1 ty2) (EqPred ty1' ty2') = (cmpTypeX env ty1 ty1') `thenCmp` (cmpTypeX env ty2 ty2')
+
+-- Constructor order: IParam < ClassP < EqPred
+cmpPredX env (IParam {}) _ = LT
+cmpPredX env (ClassP {}) (IParam {}) = GT
+cmpPredX env (ClassP {}) (EqPred {}) = LT
+cmpPredX env (EqPred {}) _ = GT
\end{code}
PredTypes are used as a FM key in TcSimplify,
| is_co_var = setTyVarKind old_var (substTy subst kind)
| otherwise = old_var
kind = tyVarKind old_var
- is_co_var = isCoercionKind kind
+ is_co_var = isCoVar old_var
\end{code}
----------------------------------------------------
splitKindFunTys :: Kind -> ([Kind],Kind)
splitKindFunTys k = splitFunTys k
+splitKindFunTysN :: Int -> Kind -> ([Kind],Kind)
+splitKindFunTysN k = splitFunTysN k
+
isUbxTupleKind, isOpenTypeKind, isArgTypeKind, isUnliftedTypeKind :: Kind -> Bool
isOpenTypeKindCon tc = tyConUnique tc == openTypeKindTyConKey
isSubKind :: Kind -> Kind -> Bool
-- (k1 `isSubKind` k2) checks that k1 <: k2
-isSubKind (TyConApp kc1 []) (TyConApp kc2 []) = kc1 `isSubKindCon` kc1
+isSubKind (TyConApp kc1 []) (TyConApp kc2 []) = kc1 `isSubKindCon` kc2
isSubKind (FunTy a1 r1) (FunTy a2 r2) = (a2 `isSubKind` a1) && (r1 `isSubKind` r2)
+isSubKind (PredTy (EqPred ty1 ty2)) (PredTy (EqPred ty1' ty2'))
+ = ty1 `tcEqType` ty1' && ty2 `tcEqType` ty2'
isSubKind k1 k2 = False
eqKind :: Kind -> Kind -> Bool
| isSubArgTypeKind k = liftedTypeKind
| otherwise = k
-isCoercionKind :: Kind -> Bool
--- All coercions are of form (ty1 :=: ty2)
--- This function is here rather than in Coercion,
--- because it's used by substTy
-isCoercionKind k | Just k' <- kindView k = isCoercionKind k'
-isCoercionKind (PredTy (EqPred {})) = True
-isCoercionKind other = False
+isEqPred :: PredType -> Bool
+isEqPred (EqPred _ _) = True
+isEqPred other = False
\end{code}