From: simonpj <unknown>
Date: Thu, 3 May 2001 08:13:39 +0000 (+0000)
Subject: [project @ 2001-05-03 08:13:39 by simonpj]
X-Git-Tag: Approximately_9120_patches~2026
X-Git-Url: http://git.megacz.com/?a=commitdiff_plain;ds=inline;h=8c0814f174aaaacbc242c88f7e51617c5bb220e7;p=ghc-hetmet.git

[project @ 2001-05-03 08:13:39 by simonpj]
Improve error message
---

diff --git a/ghc/compiler/typecheck/TcMonoType.lhs b/ghc/compiler/typecheck/TcMonoType.lhs
index ddd4f76..0e622a0 100644
--- a/ghc/compiler/typecheck/TcMonoType.lhs
+++ b/ghc/compiler/typecheck/TcMonoType.lhs
@@ -983,9 +983,10 @@ ambigErr pred ppr_ty
 		 ptext SLIT("must be reachable from the type after the =>"))]
 
 freeErr pred ppr_ty
-  = sep [ptext SLIT("The constraint") <+> quotes (pprPred pred) <+>
-		   ptext SLIT("does not mention any of the universally quantified type variables"),
-	 nest 4 (ptext SLIT("in the type") <+> quotes ppr_ty)
+  = sep [ptext SLIT("All of the type variables in the constraint") <+> quotes (pprPred pred) <+>
+		   ptext SLIT("are already in scope"),
+	 nest 4 (ptext SLIT("At least one must be universally quantified here")),
+	 ptext SLIT("In the type") <+> quotes ppr_ty
     ]
 
 polyArgTyErr ty = ptext SLIT("Illegal polymorphic type as argument:")   <+> ppr ty