X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2FdeSugar%2FDsMonad.lhs;h=83a5d212ae84eb720408de651dc585db50676ba0;hb=7bb3d1fc79521d591cd9f824893963141a7997b6;hp=1f01e1509488330fbdad886f719a455e9260242e;hpb=872148019c5c4fe7f96b12d1610234a2933696f1;p=ghc-hetmet.git

diff --git a/compiler/deSugar/DsMonad.lhs b/compiler/deSugar/DsMonad.lhs
index 1f01e15..83a5d21 100644
--- a/compiler/deSugar/DsMonad.lhs
+++ b/compiler/deSugar/DsMonad.lhs
@@ -14,7 +14,7 @@ module DsMonad (
 
 	newLocalName,
 	duplicateLocalDs, newSysLocalDs, newSysLocalsDs, newUniqueId,
-	newFailLocalDs,
+	newFailLocalDs, newPredVarDs,
 	getSrcSpanDs, putSrcSpanDs,
 	getModuleDs,
 	newUnique, 
@@ -156,7 +156,7 @@ data DsMetaVal
 initDs  :: HscEnv
 	-> Module -> GlobalRdrEnv -> TypeEnv
 	-> DsM a
-	-> IO (Maybe a)
+	-> IO (Messages, Maybe a)
 -- Print errors and warnings, if any arise
 
 initDs hsc_env mod rdr_env type_env thing_inside
@@ -170,7 +170,6 @@ initDs hsc_env mod rdr_env type_env thing_inside
 	-- Display any errors and warnings 
 	-- Note: if -Werror is used, we don't signal an error here.
 	; msgs <- readIORef msg_var
-        ; printErrorsAndWarnings dflags msgs 
 
 	; let final_res | errorsFound dflags msgs = Nothing
 		        | otherwise = case either_res of
@@ -180,7 +179,7 @@ initDs hsc_env mod rdr_env type_env thing_inside
 		-- a UserError exception.  Then it should have put an error
 		-- message in msg_var, so we just discard the exception
 
-	; return final_res }
+	; return (msgs, final_res) }
 
 initDsTc :: DsM a -> TcM a
 initDsTc thing_inside
@@ -225,12 +224,22 @@ newUniqueId :: Name -> Type -> DsM Id
 newUniqueId id = mkSysLocalM (occNameFS (nameOccName id))
 
 duplicateLocalDs :: Id -> DsM Id
-duplicateLocalDs old_local = do
-    uniq <- newUnique
-    return (setIdUnique old_local uniq)
-
+duplicateLocalDs old_local 
+  = do	{ uniq <- newUnique
+	; return (setIdUnique old_local uniq) }
+
+newPredVarDs :: PredType -> DsM Var
+newPredVarDs pred
+ | isEqPred pred
+ = do { uniq <- newUnique; 
+      ; let name = mkSystemName uniq (mkOccNameFS tcName (fsLit "co"))
+	    kind = mkPredTy pred
+      ; return (mkCoVar name kind) }
+ | otherwise
+ = newSysLocalDs (mkPredTy pred)
+ 
 newSysLocalDs, newFailLocalDs :: Type -> DsM Id
-newSysLocalDs = mkSysLocalM (fsLit "ds")
+newSysLocalDs  = mkSysLocalM (fsLit "ds")
 newFailLocalDs = mkSysLocalM (fsLit "fail")
 
 newSysLocalsDs :: [Type] -> DsM [Id]