X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Ftypes%2FType.lhs;h=8c969226d8db098008a491c55e318c7bbc73eace;hb=8b5bfdf4e780bae6c596825a1042b059f9ae4f2d;hp=aa3cd077b05898deac0bfe17e3f09ef7cbc35121;hpb=25f84fa7e4b84c3db5ba745a7881c009b778e0b1;p=ghc-hetmet.git

diff --git a/compiler/types/Type.lhs b/compiler/types/Type.lhs
index aa3cd07..8c96922 100644
--- a/compiler/types/Type.lhs
+++ b/compiler/types/Type.lhs
@@ -74,6 +74,9 @@ module Type (
 	tyVarsOfType, tyVarsOfTypes, tyVarsOfPred, tyVarsOfTheta,
 	typeKind, addFreeTyVars,
 
+        -- Type families
+        tyFamInsts,
+
 	-- Tidying up for printing
 	tidyType,      tidyTypes,
 	tidyOpenType,  tidyOpenTypes,
@@ -84,7 +87,7 @@ module Type (
 
 	-- Comparison
 	coreEqType, tcEqType, tcEqTypes, tcCmpType, tcCmpTypes, 
-	tcEqPred, tcCmpPred, tcEqTypeX, 
+	tcEqPred, tcCmpPred, tcEqTypeX, tcPartOfType, tcPartOfPred,
 
 	-- Seq
 	seqType, seqTypes,
@@ -102,7 +105,7 @@ module Type (
 	substPred, substTyVar, substTyVars, substTyVarBndr, deShadowTy, lookupTyVar,
 
 	-- Pretty-printing
-	pprType, pprParendType, pprTypeApp, pprTyThingCategory, pprForAll,
+	pprType, pprParendType, pprTypeApp, pprTyThingCategory, pprTyThing, pprForAll,
 	pprPred, pprTheta, pprThetaArrow, pprClassPred, pprKind, pprParendKind
     ) where
 
@@ -278,10 +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
@@ -294,7 +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)
@@ -709,6 +720,28 @@ addFreeTyVars ty			     = NoteTy (FTVNote (tyVarsOfType ty)) ty
 
 %************************************************************************
 %*									*
+\subsection{Type families}
+%*									*
+%************************************************************************
+
+Type family instances occuring in a type after expanding synonyms.
+
+\begin{code}
+tyFamInsts :: Type -> [(TyCon, [Type])]
+tyFamInsts ty 
+  | Just exp_ty <- tcView ty    = tyFamInsts exp_ty
+tyFamInsts (TyVarTy _)          = []
+tyFamInsts (TyConApp tc tys) 
+  | isOpenSynTyCon tc           = [(tc, tys)]
+  | otherwise                   = concat (map tyFamInsts tys)
+tyFamInsts (FunTy ty1 ty2)      = tyFamInsts ty1 ++ tyFamInsts ty2
+tyFamInsts (AppTy ty1 ty2)      = tyFamInsts ty1 ++ tyFamInsts ty2
+tyFamInsts (ForAllTy _ ty)      = tyFamInsts ty
+\end{code}
+
+
+%************************************************************************
+%*									*
 \subsection{TidyType}
 %*									*
 %************************************************************************
@@ -974,6 +1007,29 @@ tcEqTypeX :: RnEnv2 -> Type -> Type -> Bool
 tcEqTypeX env t1 t2 = isEqual $ cmpTypeX env t1 t2
 \end{code}
 
+Checks whether the second argument is a subterm of the first.  (We don't care
+about binders, as we are only interested in syntactic subterms.)
+
+\begin{code}
+tcPartOfType :: Type -> Type -> Bool
+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
+tcPartOfType t1 (PredTy p2)     = tcPartOfPred t1 p2
+tcPartOfType t1 (TyConApp _ ts) = any (tcPartOfType t1) ts
+tcPartOfType t1 (NoteTy _ t2)   = tcPartOfType t1 t2
+
+tcPartOfPred :: Type -> PredType -> Bool
+tcPartOfPred t1 (IParam _ t2)  = tcPartOfType t1 t2
+tcPartOfPred t1 (ClassP _ ts)  = any (tcPartOfType t1) ts
+tcPartOfPred t1 (EqPred s2 t2) = tcPartOfType t1 s2 || tcPartOfType t1 t2
+\end{code}
+
 Now here comes the real worker
 
 \begin{code}