At the cost of more complexity to the vm, it could be the made the count of (non-nil) numeric keys. My only complaint is that besides from the #+1 speedup, it'd probably have even less actual use then the current behaviour (which as we were shown has been used for finding unique ids). - AlexAs I pointed out, it would also make the manipulation of "mixed tables" (tables with arrays plus some extra fields) quite tricky. -- Roberto