[project @ 2005-08-12 08:32:16 by simonpj]

Grr: another wibble to duplicate signature detection

diff --git a/ghc/compiler/rename/RnBinds.lhs b/ghc/compiler/rename/RnBinds.lhs
index 96ce11b..f067e5d 100644 (file)
--- a/ghc/compiler/rename/RnBinds.lhs
+++ b/ghc/compiler/rename/RnBinds.lhs
@@ -45,6 +45,7 @@ import Digraph                ( SCC(..), stronglyConnComp )
 import Bag
 import Outputable
 import Maybes          ( orElse, fromJust, isJust )
+import Util            ( filterOut )
 import Monad           ( foldM )
 \end{code}
 
@@ -501,14 +502,14 @@ check_sigs :: (LSig Name -> Bool) -> [LSig Name] -> RnM ()
 check_sigs ok_sig sigs 
        -- Check for (a) duplicate signatures
        --           (b) signatures for things not in this group
-  = do { mappM_ unknownSigErr (filter bad sigs)
-       ; mappM_ dupSigDeclErr (findDupsEq eqHsSig sigs) }
+  = do { mappM_ unknownSigErr (filter (not . ok_sig) sigs')
+       ; mappM_ dupSigDeclErr (findDupsEq eqHsSig sigs') }
   where
        -- Don't complain about an unbound name again
-    bad sig = not (ok_sig sig) && 
-             case sigName sig of
-               Just n | isUnboundName n -> False
-               other                    -> True
+    sigs' = filterOut bad_name sigs
+    bad_name sig = case sigName sig of
+                       Just n -> isUnboundName n
+                       other  -> False
 
 -- We use lookupLocatedSigOccRn in the signatures, which is a little bit unsatisfactory
 -- because this won't work for: