-getTyCon :: TyThing -> TyCon
-getTyCon (ATyCon tc) = tc
-getTyCon (AClass cl) = classTyCon cl
-getTyCon _ = panic "getTyCon"
+getTyCon :: TyThing -> Maybe TyCon
+getTyCon (ATyCon tc) = Just tc
+getTyCon (AClass cl) = Just (classTyCon cl)
+getTyCon _ = Nothing