Bug-fix for infix function definitions (parse/rename)

[ghc-hetmet.git] / compiler / rename / RnTypes.lhs

diff --git a/compiler/rename/RnTypes.lhs b/compiler/rename/RnTypes.lhs
index d7d435c..e209036 100644 (file)
--- a/compiler/rename/RnTypes.lhs
+++ b/compiler/rename/RnTypes.lhs
@@ -416,7 +416,14 @@ checkPrecMatch True op (MatchGroup ms _)
       = checkPrec op (unLoc p1) False  `thenM_`
         checkPrec op (unLoc p2) True
 
-    check _ = panic "checkPrecMatch"
+    check _ = return ()        
+       -- This can happen.  Consider
+       --      a `op` True = ...
+       --      op          = ...
+       -- The infix flag comes from the first binding of the group
+       -- but the second eqn has no args (an error, but not discovered
+       -- until the type checker).  So we don't want to crash on the
+       -- second eqn.
 
 checkPrec op (ConPatIn op1 (InfixCon _ _)) right
   = lookupFixityRn op          `thenM` \  op_fix@(Fixity op_prec  op_dir) ->