From: simonpj <unknown>
Date: Tue, 23 Apr 2002 08:52:16 +0000 (+0000)
Subject: [project @ 2002-04-23 08:52:16 by simonpj]
X-Git-Tag: Approx_11550_changesets_converted~2118
X-Git-Url: http://git.megacz.com/?a=commitdiff_plain;h=18f074c56a971ecbaf05957514b7a020cd14e81f;p=ghc-hetmet.git

[project @ 2002-04-23 08:52:16 by simonpj]
Without -fglasow-exts, quantify over all mentioned type vars in type sigs
---

diff --git a/ghc/compiler/rename/RnTypes.lhs b/ghc/compiler/rename/RnTypes.lhs
index 4ef0582..afe921d 100644
--- a/ghc/compiler/rename/RnTypes.lhs
+++ b/ghc/compiler/rename/RnTypes.lhs
@@ -19,6 +19,7 @@ import RdrName	( elemRdrEnv )
 import NameSet	( FreeVars )
 import Unique	( Uniquable(..) )
 
+import CmdLineOpts	( DynFlag(Opt_GlasgowExts) )
 import List		( nub )
 import ListSetOps	( removeDupsEq )
 import Outputable
@@ -64,11 +65,17 @@ rnHsType doc (HsForAllTy Nothing ctxt ty)
 	-- Given the signature  C => T  we universally quantify 
 	-- over FV(T) \ {in-scope-tyvars} 
   = getLocalNameEnv		`thenRn` \ name_env ->
+    doptRn Opt_GlasgowExts	`thenRn` \ opt_GlasgowExts ->
     let
 	mentioned_in_tau  = extractHsTyRdrTyVars ty
 	mentioned_in_ctxt = extractHsCtxtRdrTyVars ctxt
 	mentioned	  = nub (mentioned_in_tau ++ mentioned_in_ctxt)
-	forall_tyvars	  = filter (not . (`elemRdrEnv` name_env)) mentioned
+
+	-- Don't quantify over type variables that are in scope,
+	-- when GlasgowExts is on
+	forall_tyvars
+	   | opt_GlasgowExts = filter (not . (`elemRdrEnv` name_env)) mentioned
+	   | otherwise	     = mentioned
     in
     rnForAll doc (map UserTyVar forall_tyvars) ctxt ty