> On Nov 22, 2017, at 2:42 AM, Remi Forax <fo...@univ-mlv.fr> wrote: > > I think we do not need Q types, Q types are use site annotations, and here we > want declaration site annotations (let say that this class is a value class, > the ACC_VALUE). > > If we have no Q type, it means that R types and U types are the same thing, > everything is a U type. In term of migration, it means that L types need to > have their semantics extended to work as U types.
Yeah. We discussed this and I mentioned it in the notes, but it could use a deeper exploration at some point. As a minimum, there probably needs to be *some* way to indicate that a field can be flattened and may not be null. If a field has a U type, the referenced class would have to be loaded before we could tell if it's referencing a value class or not, and that's costly. —Dan
