> Can I specify that implementations of foo can throw no, some, or all exceptions? just because theres the possibility of a throw in the signature, does not me

> Can I specify that implementations of foo can throw no, some, or all exceptions? just because theres the possibility of a throw in the signature, does not mean it has to be done in a concrete implementation, and if implementations are really to be exchangable, it has to be handled in case implementation changes. > What would it even mean to write something like throws *? Roughly similar to "throws Exception" or "throws Throwable" - that it may throw whatever you have under the sun? > Concretely, checked exceptions in Java failed because Java lacks “throwingness polymorphism”, if you will. it does allow for extending exceptions, so an interface can define some exceptions that are basic, and implementations can then choose to extend those to provide MORE detail if needed. > Was Java wrong to add checked exceptions? No. They took a risk and it didn’t pay off. Uhm.... Im gonna go ahead and use some other opinion on this