Extended TyCon and friends to represent family declarations

[ghc-hetmet.git] / compiler / types / Type.lhs

diff --git a/compiler/types/Type.lhs b/compiler/types/Type.lhs
index fd8e8c5..a7aeeec 100644 (file)
--- a/compiler/types/Type.lhs
+++ b/compiler/types/Type.lhs
@@ -12,7 +12,7 @@ module Type (
 
        -- Kinds
         Kind, SimpleKind, KindVar,
-        kindFunResult, splitKindFunTys, 
+        kindFunResult, splitKindFunTys, splitKindFunTysN,
 
         liftedTypeKindTyCon, openTypeKindTyCon, unliftedTypeKindTyCon,
         argTypeKindTyCon, ubxTupleKindTyCon,
@@ -24,7 +24,7 @@ module Type (
 
         isLiftedTypeKind, isUnliftedTypeKind, isOpenTypeKind,
         isUbxTupleKind, isArgTypeKind, isKind, isTySuperKind, 
-        isCoSuperKind, isSuperKind, isCoercionKind,
+        isCoSuperKind, isSuperKind, isCoercionKind, isEqPred,
        mkArrowKind, mkArrowKinds,
 
         isSubArgTypeKind, isSubOpenTypeKind, isSubKind, defaultKind, eqKind,
@@ -56,7 +56,7 @@ module Type (
        predTypeRep, mkPredTy, mkPredTys,
 
        -- Newtypes
-       splitRecNewType_maybe,
+       splitRecNewType_maybe, newTyConInstRhs,
 
        -- Lifting and boxity
        isUnLiftedType, isUnboxedTupleType, isAlgType, isPrimitiveType,
@@ -106,7 +106,7 @@ import TypeRep
 
 -- friends:
 import Var     ( Var, TyVar, tyVarKind, tyVarName, 
-                 setTyVarName, setTyVarKind )
+                 setTyVarName, setTyVarKind, mkWildCoVar )
 import VarEnv
 import VarSet
 
@@ -164,7 +164,9 @@ coreView :: Type -> Maybe Type
 -- 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),
@@ -305,10 +307,11 @@ splitAppTys ty = split ty ty []
 
 \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)
@@ -410,6 +413,12 @@ splitNewTyConApp_maybe (TyConApp tc tys) = Just (tc, tys)
 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
+
 \end{code}
 
 
@@ -590,6 +599,7 @@ predTypeRep (IParam _ ty)     = ty
 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}
 
 
@@ -1019,6 +1029,7 @@ cmpPredX env (IParam n1 ty1) (IParam n2 ty2) = (n1 `compare` n2) `thenCmp` cmpTy
 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')
 \end{code}
 
 PredTypes are used as a FM key in TcSimplify, 
@@ -1360,6 +1371,9 @@ kindFunResult k = funResultTy k
 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
@@ -1417,6 +1431,8 @@ isSubKind :: Kind -> Kind -> Bool
 -- (k1 `isSubKind` k2) checks that k1 <: k2
 isSubKind (TyConApp kc1 []) (TyConApp kc2 []) = kc1 `isSubKindCon` kc1
 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
@@ -1459,4 +1475,8 @@ isCoercionKind :: Kind -> Bool
 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}