X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Ftypecheck%2FTcUnify.lhs;h=572ad4437cfd2489ad95f2a6f266c1b2fe54db80;hp=0dfe3941c53d0f2c9eafe18cbf2cca60414e7d9f;hb=c0687066474aa4ce4912f31a5c09c1bcd673fb06;hpb=fdf8656855d26105ff36bdd24d41827b05037b91

diff --git a/compiler/typecheck/TcUnify.lhs b/compiler/typecheck/TcUnify.lhs
index 0dfe394..572ad44 100644
--- a/compiler/typecheck/TcUnify.lhs
+++ b/compiler/typecheck/TcUnify.lhs
@@ -20,7 +20,7 @@ module TcUnify (
   matchExpectedListTy, matchExpectedPArrTy, 
   matchExpectedTyConApp, matchExpectedAppTy, 
   matchExpectedFunTys, matchExpectedFunKind,
-  wrapFunResCoercion
+  wrapFunResCoercion, failWithMisMatch
   ) where
 
 #include "HsVersions.h"
@@ -888,8 +888,8 @@ uUnfilledVars origin swapped tv1 details1 tv2 details2
     ty1       = mkTyVarTy tv1
     ty2       = mkTyVarTy tv2
 
-    nicer_to_update_tv1 _         (SigTv _) = True
-    nicer_to_update_tv1 (SigTv _) _         = False
+    nicer_to_update_tv1 _     SigTv = True
+    nicer_to_update_tv1 SigTv _     = False
     nicer_to_update_tv1 _         _         = isSystemName (Var.varName tv1)
         -- Try not to update SigTvs; and try to update sys-y type
         -- variables in preference to ones gotten (say) by