fix some coercion kind representation things, extend exprIsConApp_maybe to non-vanilla

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

diff --git a/compiler/types/Type.lhs b/compiler/types/Type.lhs
index ccabfb7..b7f521a 100644 (file)
--- a/compiler/types/Type.lhs
+++ b/compiler/types/Type.lhs
@@ -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,
@@ -47,7 +47,7 @@ module Type (
        splitTyConApp_maybe, splitTyConApp, 
         splitNewTyConApp_maybe, splitNewTyConApp,
 
-       repType, typePrimRep, coreView, tcView, stgView, kindView,
+       repType, typePrimRep, coreView, tcView, kindView,
 
        mkForAllTy, mkForAllTys, splitForAllTy_maybe, splitForAllTys, 
        applyTy, applyTys, isForAllTy, dropForAlls,
@@ -56,7 +56,7 @@ module Type (
        predTypeRep, mkPredTy, mkPredTys,
 
        -- Newtypes
-       splitRecNewType_maybe,
+       splitRecNewType_maybe, newTyConInstRhs,
 
        -- Lifting and boxity
        isUnLiftedType, isUnboxedTupleType, isAlgType, isPrimitiveType,
@@ -106,31 +106,26 @@ import TypeRep
 
 -- friends:
 import Var     ( Var, TyVar, tyVarKind, tyVarName, 
-                 setTyVarName, setTyVarKind, mkTyVar, isTyVar )
-import Name    ( Name(..) )
-import Unique  ( Unique )
+                 setTyVarName, setTyVarKind, mkWildTyVar )
 import VarEnv
 import VarSet
 
 import OccName ( tidyOccName )
-import Name    ( NamedThing(..), mkInternalName, tidyNameOcc )
+import Name    ( NamedThing(..), tidyNameOcc )
 import Class   ( Class, classTyCon )
 import PrelNames( openTypeKindTyConKey, unliftedTypeKindTyConKey, 
-                  ubxTupleKindTyConKey, argTypeKindTyConKey, 
-                  eqCoercionKindTyConKey )
+                  ubxTupleKindTyConKey, argTypeKindTyConKey )
 import TyCon   ( TyCon, isRecursiveTyCon, isPrimTyCon,
                  isUnboxedTupleTyCon, isUnLiftedTyCon,
                  isFunTyCon, isNewTyCon, newTyConRep, newTyConRhs,
                  isAlgTyCon, tyConArity, isSuperKindTyCon,
                  tcExpandTyCon_maybe, coreExpandTyCon_maybe,
-                  stgExpandTyCon_maybe,
                  tyConKind, PrimRep(..), tyConPrimRep, tyConUnique,
                   isCoercionTyCon_maybe, isCoercionTyCon
                )
 
 -- others
 import StaticFlags     ( opt_DictsStrict )
-import SrcLoc          ( noSrcLoc )
 import Util            ( mapAccumL, seqList, lengthIs, snocView, thenCmp, isEqual, all2 )
 import Outputable
 import UniqSet         ( sizeUniqSet )         -- Should come via VarSet
@@ -169,7 +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),
@@ -177,19 +174,6 @@ coreView (TyConApp tc tys) | Just (tenv, rhs, tys') <- coreExpandTyCon_maybe tc
                                -- partially-applied type constructor; indeed, usually will!
 coreView ty               = Nothing
 
-{-# INLINE stgView #-}
-stgView :: Type -> Maybe Type
--- When generating STG from Core it is important that we look through newtypes
--- but for the rest of Core we are just using coercions.  This does just what
--- coreView USED to do.
-stgView (NoteTy _ ty)     = Just ty
-stgView (PredTy p)        = Just (predTypeRep p)
-stgView (TyConApp tc tys) | Just (tenv, rhs, tys') <- stgExpandTyCon_maybe tc tys 
-                          = Just (mkAppTys (substTy (mkTopTvSubst tenv) rhs) tys')
-                               -- Its important to use mkAppTys, rather than (foldl AppTy),
-                               -- because the function part might well return a 
-                               -- partially-applied type constructor; indeed, usually will!
-stgView ty                = Nothing
 
 
 -----------------------------------------------
@@ -323,10 +307,11 @@ splitAppTys ty = split ty ty []
 
 \begin{code}
 mkFunTy :: Type -> Type -> Type
+mkFunTy (PredTy (EqPred ty1 ty2)) res = mkForAllTy (mkWildTyVar (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)
@@ -428,6 +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}
 
 
@@ -608,6 +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}
 
 
@@ -695,8 +687,9 @@ tyVarsOfTypes :: [Type] -> TyVarSet
 tyVarsOfTypes tys = foldr (unionVarSet.tyVarsOfType) emptyVarSet tys
 
 tyVarsOfPred :: PredType -> TyVarSet
-tyVarsOfPred (IParam _ ty)  = tyVarsOfType ty
-tyVarsOfPred (ClassP _ tys) = tyVarsOfTypes tys
+tyVarsOfPred (IParam _ ty)    = tyVarsOfType ty
+tyVarsOfPred (ClassP _ tys)   = tyVarsOfTypes tys
+tyVarsOfPred (EqPred ty1 ty2) = tyVarsOfType ty1 `unionVarSet` tyVarsOfType ty2
 
 tyVarsOfTheta :: ThetaType -> TyVarSet
 tyVarsOfTheta = foldr (unionVarSet . tyVarsOfPred) emptyVarSet
@@ -770,6 +763,7 @@ tidyTypes env tys = map (tidyType env) tys
 tidyPred :: TidyEnv -> PredType -> PredType
 tidyPred env (IParam n ty)     = IParam n (tidyType env ty)
 tidyPred env (ClassP clas tys) = ClassP clas (tidyTypes env tys)
+tidyPred env (EqPred ty1 ty2)  = EqPred (tidyType env ty1) (tidyType env ty2)
 \end{code}
 
 
@@ -888,8 +882,9 @@ seqNote :: TyNote -> ()
 seqNote (FTVNote set) = sizeUniqSet set `seq` ()
 
 seqPred :: PredType -> ()
-seqPred (ClassP c tys) = c  `seq` seqTypes tys
-seqPred (IParam n ty)  = n  `seq` seqType ty
+seqPred (ClassP c tys)   = c `seq` seqTypes tys
+seqPred (IParam n ty)    = n `seq` seqType ty
+seqPred (EqPred ty1 ty2) = seqType ty1 `seq` seqType ty2
 \end{code}
 
 
@@ -1432,6 +1427,8 @@ 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
@@ -1474,4 +1471,8 @@ 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}