Add ASSERTs to all calls of nameModule

[ghc-hetmet.git] / compiler / rename / RnEnv.lhs

diff --git a/compiler/rename/RnEnv.lhs b/compiler/rename/RnEnv.lhs
index a4c4afd..a0d323d 100644 (file)
--- a/compiler/rename/RnEnv.lhs
+++ b/compiler/rename/RnEnv.lhs
@@ -30,7 +30,7 @@ module RnEnv (
        mapFvRn, mapFvRnCPS,
        warnUnusedMatches, warnUnusedModules, warnUnusedImports, 
        warnUnusedTopBinds, warnUnusedLocalBinds,
-       dataTcOccs, unknownNameErr
+       dataTcOccs, unknownNameErr, perhapsForallMsg
     ) where
 
 #include "HsVersions.h"
@@ -868,11 +868,9 @@ checkShadowedNames doc_str (global_env,local_env) loc_rdr_names
 \begin{code}
 -- A useful utility
 mapFvRn :: (a -> RnM (b, FreeVars)) -> [a] -> RnM ([b], FreeVars)
-mapFvRn f xs = mappM f xs      `thenM` \ stuff ->
-              let
-                 (ys, fvs_s) = unzip stuff
-              in
-              returnM (ys, plusFVs fvs_s)
+mapFvRn f xs = do stuff <- mappM f xs
+                  case unzip stuff of
+                      (ys, fvs_s) -> returnM (ys, plusFVs fvs_s)
 
 -- because some of the rename functions are CPSed:
 -- maps the function across the list from left to right; 
@@ -986,9 +984,13 @@ unknownNameErr rdr_name
                          <+> quotes (ppr rdr_name))
         , extra ]
   where
-    extra | rdr_name == forall_tv_RDR 
-         = ptext (sLit "Perhaps you intended to use -XRankNTypes or similar flag")
-         | otherwise = empty
+    extra | rdr_name == forall_tv_RDR = perhapsForallMsg
+         | otherwise                 = empty
+
+perhapsForallMsg :: SDoc
+perhapsForallMsg 
+  = vcat [ ptext (sLit "Perhaps you intended to use -XRankNTypes or similar flag")
+        , ptext (sLit "to enable explicit-forall syntax: forall <tvs>. <type>")]
 
 unknownSubordinateErr :: SDoc -> RdrName -> SDoc
 unknownSubordinateErr doc op   -- Doc is "method of class" or