X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Ftypecheck%2FTcUnify.lhs;h=e229b8be066b913a2eb59f753e43d5551a06f535;hb=37a6a52facd1c3999ce4472c50b0030568be1e04;hp=4fc50b33256e642b0331aad8a57854d9d44a0a8a;hpb=d1796b5266121ff6930d6cabba6201e48708703b;p=ghc-hetmet.git

diff --git a/compiler/typecheck/TcUnify.lhs b/compiler/typecheck/TcUnify.lhs
index 4fc50b3..e229b8b 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"
@@ -899,8 +899,8 @@ 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