Not sure if const/private are a good fit for contracts but things like "account balance is always positive" can be done right now with contracts.coffee using ob

Not sure if const/private are a good fit for contracts but things like "account balance is always positive" can be done right now with contracts.coffee using object invariants. For example, verifying the invariants of a binary search tree hold [1]. [1] http://disnetdev.com/contracts.coffee/#duck http://disnetdev.com/contracts.coffee/#duck