> Contracts are useless.
No, they are not.
1. If the code doesn't conform to the contract, it will fail on the contract boundary, with a well-defined error. If this is useless, then `assert` is also useless, which it is, of course, not.
2. With a sufficiently well-designed language and sufficiently smart compiler, you can move some contract checks to compile-time. See Racket.
3. If your language supports both static and dynamic typing, the contracts are a dual of static types, which lets you interface the static and dynamic parts of the code seamlessly and automatically (in both directions). Again, see Racket.
Meta: I wonder, why it's mostly static-typing proponents who aggressively evangelize, insult the other side, are 110% sure they're right even though there is no scientific evidence and so on. Could it be the bondage&discipline approach of static typing just appeals to people with a certain mindset, who are statistically more probable to engage in such behaviors, no matter the subject?
