Do superpackages can mark exported classes as final? What do i mean is can i export a class "as final" instead of marking it final. I ask because in some situations separating a unusual object capability into a sub-type would be advantageous memory-wise, but the type has to be final, because of backward compatibility or design.
I'm going to give a rather radical example from java.lang: String has a substring capability and it uses two int fields (of 3 + a char array) to do it, when it could return a private subclass of string on substring. It doesn't, besides serialization complications, i guess because string is designed not be extended for immutability concerns. Problem is final has no granularity, and is all or nothing, namespace-wise. Well, i asked the question, but i don't have much hope.
