Remove unused imports

[ghc-hetmet.git] / compiler / deSugar / DsMonad.lhs

diff --git a/compiler/deSugar/DsMonad.lhs b/compiler/deSugar/DsMonad.lhs
index 1f01e15..58a154a 100644 (file)
--- 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, 
@@ -53,10 +53,8 @@ import Type
 import UniqSupply
 import Name
 import NameEnv
-import OccName
 import DynFlags
 import ErrUtils
-import MonadUtils
 import FastString
 
 import Data.IORef
@@ -156,7 +154,7 @@ 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 +168,6 @@ 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 +177,7 @@ 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 +222,22 @@ 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]