FIX: mkWWcpr takes open alg types into account

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

diff --git a/compiler/types/Type.lhs b/compiler/types/Type.lhs
index c1e0544..ab47c4c 100644 (file)
--- a/compiler/types/Type.lhs
+++ b/compiler/types/Type.lhs
@@ -67,8 +67,8 @@ module Type (
        newTyConInstRhs,
 
        -- Lifting and boxity
-       isUnLiftedType, isUnboxedTupleType, isAlgType, isPrimitiveType,
-       isStrictType, isStrictPred, 
+       isUnLiftedType, isUnboxedTupleType, isAlgType, isClosedAlgType,
+       isPrimitiveType, isStrictType, isStrictPred, 
 
        -- Free variables
        tyVarsOfType, tyVarsOfTypes, tyVarsOfPred, tyVarsOfTheta,
@@ -281,10 +281,12 @@ repSplitAppTy_maybe :: Type -> Maybe (Type,Type)
 -- Does the AppTy split, but assumes that any view stuff is already done
 repSplitAppTy_maybe (FunTy ty1 ty2)   = Just (TyConApp funTyCon [ty1], ty2)
 repSplitAppTy_maybe (AppTy ty1 ty2)   = Just (ty1, ty2)
-repSplitAppTy_maybe (TyConApp tc tys) = case snocView tys of
-                                               Just (tys', ty') -> Just (TyConApp tc tys', ty')
-                                               Nothing          -> Nothing
-repSplitAppTy_maybe other = Nothing
+repSplitAppTy_maybe (TyConApp tc tys) 
+  | not (isOpenSynTyCon tc) || length tys > tyConArity tc 
+  = case snocView tys of       -- never create unsaturated type family apps
+      Just (tys', ty') -> Just (TyConApp tc tys', ty')
+      Nothing         -> Nothing
+repSplitAppTy_maybe _other = Nothing
 -------------
 splitAppTy :: Type -> (Type, Type)
 splitAppTy ty = case splitAppTy_maybe ty of
@@ -297,7 +299,13 @@ splitAppTys ty = split ty ty []
   where
     split orig_ty ty args | Just ty' <- coreView ty = split orig_ty ty' args
     split orig_ty (AppTy ty arg)        args = split ty ty (arg:args)
-    split orig_ty (TyConApp tc tc_args) args = (TyConApp tc [], tc_args ++ args)
+    split orig_ty (TyConApp tc tc_args) args 
+      = let -- keep type families saturated
+            n | isOpenSynTyCon tc = tyConArity tc
+              | otherwise         = 0
+            (tc_args1, tc_args2)  = splitAt n tc_args
+        in
+        (TyConApp tc tc_args1, tc_args2 ++ args)
     split orig_ty (FunTy ty1 ty2)       args = ASSERT( null args )
                                               (TyConApp funTyCon [], [ty1,ty2])
     split orig_ty ty                   args = (orig_ty, args)
@@ -853,10 +861,19 @@ isUnboxedTupleType ty = case splitTyConApp_maybe ty of
 
 -- Should only be applied to *types*; hence the assert
 isAlgType :: Type -> Bool
-isAlgType ty = case splitTyConApp_maybe ty of
-                       Just (tc, ty_args) -> ASSERT( ty_args `lengthIs` tyConArity tc )
-                                             isAlgTyCon tc
-                       other              -> False
+isAlgType ty 
+  = case splitTyConApp_maybe ty of
+      Just (tc, ty_args) -> ASSERT( ty_args `lengthIs` tyConArity tc )
+                           isAlgTyCon tc
+      _other            -> False
+
+-- Should only be applied to *types*; hence the assert
+isClosedAlgType :: Type -> Bool
+isClosedAlgType ty
+  = case splitTyConApp_maybe ty of
+      Just (tc, ty_args) -> ASSERT( ty_args `lengthIs` tyConArity tc )
+                           isAlgTyCon tc && not (isOpenTyCon tc)
+      _other            -> False
 \end{code}
 
 @isStrictType@ computes whether an argument (or let RHS) should
@@ -1004,9 +1021,11 @@ about binders, as we are only interested in syntactic subterms.)
 
 \begin{code}
 tcPartOfType :: Type -> Type -> Bool
-tcPartOfType t1              t2 = tcEqType t1 t2
+tcPartOfType t1              t2 
+  | tcEqType t1 t2              = True
 tcPartOfType t1              t2 
   | Just t2' <- tcView t2       = tcPartOfType t1 t2'
+tcPartOfType _  (TyVarTy _)     = False
 tcPartOfType t1 (ForAllTy _ t2) = tcPartOfType t1 t2
 tcPartOfType t1 (AppTy s2 t2)   = tcPartOfType t1 s2 || tcPartOfType t1 t2
 tcPartOfType t1 (FunTy s2 t2)   = tcPartOfType t1 s2 || tcPartOfType t1 t2