X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Frename%2FRnEnv.lhs;h=a0d323ded322ff039c8861d9b5906aaa96e0c501;hb=66579ff945831c5fc9a17c58c722ff01f2268d76;hp=a4c4afd3126bfc88556fe3bccd68ec488392aa04;hpb=1867a7bb8c59ea514b4f47f5434842543933ec9a;p=ghc-hetmet.git

diff --git a/compiler/rename/RnEnv.lhs b/compiler/rename/RnEnv.lhs
index a4c4afd..a0d323d 100644
--- 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