[project @ 2000-06-30 13:10:38 by simonpj]

Improve error message

diff --git a/ghc/compiler/typecheck/TcMonoType.lhs b/ghc/compiler/typecheck/TcMonoType.lhs
index 2e6a570..c535684 100644 (file)
--- a/ghc/compiler/typecheck/TcMonoType.lhs
+++ b/ghc/compiler/typecheck/TcMonoType.lhs
@@ -201,7 +201,7 @@ tc_type_kind (HsUsgForAllTy uv_name ty)
       tc_type_kind ty                     `thenTc` \ (kind, tc_ty) ->
       returnTc (kind, mkUsForAllTy uv tc_ty)
 
-tc_type_kind (HsForAllTy (Just tv_names) context ty)
+tc_type_kind full_ty@(HsForAllTy (Just tv_names) context ty)
   = tcExtendTyVarScope tv_names                $ \ forall_tyvars ->
     tcContext context                  `thenTc` \ theta ->
     tc_type_kind ty                    `thenTc` \ (kind, tau) ->
@@ -240,8 +240,8 @@ tc_type_kind (HsForAllTy (Just tv_names) context ty)
                              not (ct_var `elemUFM` extended_tau_vars)
        is_free ct_var      = not (ct_var `elem` forall_tyvars)
 
-       check_pred pred = checkTc (not any_ambig) (ambigErr pred ty) `thenTc_`
-                         checkTc (not all_free)  (freeErr  pred ty)
+       check_pred pred = checkTc (not any_ambig) (ambigErr pred full_ty) `thenTc_`
+                         checkTc (not all_free)  (freeErr  pred full_ty)
              where 
                ct_vars   = varSetElems (tyVarsOfPred pred)
                any_ambig = is_source_polytype && any is_ambig ct_vars