X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2FcoreSyn%2FCoreSubst.lhs;h=3fe48009a8b3f9e474ab957ec23c871bc5feb438;hp=f1f02d9b9c9c7bd03540e8aa6383ac0078e38cc0;hb=794c2f4c8829ba3166c9bdb471856bc00c21f001;hpb=94fd9ad3745d9d270648aa5d7d87f49a0dafabd4

diff --git a/compiler/coreSyn/CoreSubst.lhs b/compiler/coreSyn/CoreSubst.lhs
index f1f02d9..3fe4800 100644
--- a/compiler/coreSyn/CoreSubst.lhs
+++ b/compiler/coreSyn/CoreSubst.lhs
@@ -227,10 +227,10 @@ lookupTvSubst (Subst _ _ tvs) v = lookupVarEnv tvs v `orElse` Type.mkTyVarTy v
 --   No left-right shadowing
 --   ie the substitution for   (\x \y. e) a1 a2
 --      so neither x nor y scope over a1 a2
-mkOpenSubst :: [(Var,CoreArg)] -> Subst
-mkOpenSubst pairs = Subst (mkInScopeSet (exprsFreeVars (map snd pairs)))
-	    	          (mkVarEnv [(id,e)  | (id, e) <- pairs, isId id])
-			  (mkVarEnv [(tv,ty) | (tv, Type ty) <- pairs])
+mkOpenSubst :: InScopeSet -> [(Var,CoreArg)] -> Subst
+mkOpenSubst in_scope pairs = Subst in_scope
+	    	          	   (mkVarEnv [(id,e)  | (id, e) <- pairs, isId id])
+			  	   (mkVarEnv [(tv,ty) | (tv, Type ty) <- pairs])
 
 ------------------------------
 isInScope :: Var -> Subst -> Bool