Yes, that was a typo and irrelevant to the discussion which is can moose classes return null from constructors? I made my classes have a valid flag, and stringify to "" if this is false, catch all exceptions within moose and this way I am able to use this idiom, in fact it works well. I think Moose should not be so prescriptive, exceptions have their place, and I'll respect your judgement that its a better way to do things, but Moose should not force you to do everything the best way, your best may not be the same as mine. That's my humble opinion in any case.