In your other email I guess you are referring to anonymous classes
implementing a sealed interface, right? E.g.
sealed interface Foo {
void m();
/* static final */ Foo f1 = new Foo() { ... }
/* static final */ Foo f2 = () -> {};
}
Right. We already restrict anon and lambda instances of the sealed
type. Not only can't we stably write down their types in the PS
attribute, but even if we could, it's so easy to accidentally lose
exhaustiveness.
(*) there's also a technical reason as to why inferring permitted
types based on things inside field initializers and method bodies is
not sound: again it has to do with annotation processing. Presumably
you want all your inference completed before annotation processors are
run. But, by design, annotation processor only requires declarations
to be processed, not entire method bodies. So it would not be
possible, under the current regime at least, to gather up all
permitted types inside all method bodies _before_ annotation processing.
Yep.
