[project @ 2000-07-14 08:17:36 by simonpj]

[ghc-hetmet.git] / ghc / compiler / typecheck / TcInstDcls.lhs

diff --git a/ghc/compiler/typecheck/TcInstDcls.lhs b/ghc/compiler/typecheck/TcInstDcls.lhs
index e55ea76..fd2b5dd 100644 (file)
--- a/ghc/compiler/typecheck/TcInstDcls.lhs
+++ b/ghc/compiler/typecheck/TcInstDcls.lhs
@@ -28,9 +28,9 @@ import TcEnv          ( ValueEnv, tcExtendGlobalValEnv, tcExtendTyVarEnvForMeths,
                          tcAddImportedIdInfo, tcInstId
                        )
 import TcInstUtil      ( InstInfo(..), classDataCon )
-import TcMonoType      ( tcHsTopType )
+import TcMonoType      ( tcHsSigType )
 import TcSimplify      ( tcSimplifyAndCheck )
-import TcType          ( TcTyVar, zonkTcTyVarBndr )
+import TcType          ( TcTyVar, zonkTcSigTyVars )
 
 import Bag             ( emptyBag, unitBag, unionBags, unionManyBags,
                          foldBag, Bag
@@ -169,7 +169,7 @@ tcInstDecl1 unf_env (InstDecl poly_ty binds uprags dfun_name src_loc)
     tcAddSrcLoc src_loc                        $
 
        -- Type-check all the stuff before the "where"
-    tcHsTopType poly_ty                        `thenTc` \ poly_ty' ->
+    tcHsSigType poly_ty                        `thenTc` \ poly_ty' ->
     let
        (tyvars, theta, dict_ty) = splitSigmaTy poly_ty'
        constr                   = classesOfPreds theta
@@ -365,8 +365,8 @@ tcInstDecl2 (InstInfo clas inst_tyvars inst_tys
 
        -- tcMethodBind has checked that the class_tyvars havn't
        -- been unified with each other or another type, but we must
-       -- still zonk them
-    mapNF_Tc zonkTcTyVarBndr inst_tyvars'      `thenNF_Tc` \ zonked_inst_tyvars ->
+       -- still zonk them before passing them to tcSimplifyAndCheck
+    zonkTcSigTyVars inst_tyvars'       `thenNF_Tc` \ zonked_inst_tyvars ->
     let
         inst_tyvars_set = mkVarSet zonked_inst_tyvars