----- Mail original ----- > De: "Brian Goetz" <brian.go...@oracle.com> > À: "Remi Forax" <fo...@univ-mlv.fr>, "Stuart Marks" <stuart.ma...@oracle.com> > Cc: "core-libs-dev" <core-libs-dev@openjdk.java.net> > Envoyé: Mardi 19 Mars 2019 00:58:04 > Objet: Re: Proposal: JDK-8148917 Enhanced-For Statement Should Allow Streams
>> My fear is more than we will want in the future to have one code for all >> kinds >> of Stream, but Stream<Object> will have to implement Iterable<Object> while >> Stream<int> will not, this not something you can actually do with the current >> generics, we may be able to do that with the reified generics but some >> languages that already have reified generics like Swift are not able to do >> that. >> So by making Stream<T> to have different set of supertypes than Stream<int>, >> you >> are forcing the future reified generics implementation to work on this case >> because we will never introduce an implementation of reified generics that >> doesn't support the classe of java.util. > > This will work fine; Stream<T> <: IterableOnce<T>, and when we can > instantiate T=int in the first, we'll be able to do so in the second as > well. (Having spent hundreds of hours banging my head against how we're > going to migrate collections and stream to specialization, this one is > not even on the list.) for some reason i was convinced that IntStream.iterator() was returning a PrimitiveIterator.OfInt and not an Iterator<Integer>, so yes, it will work but i don't understand why it's not BaseStream instead of Stream<Object> that inherits from Iterable. And i still think that add IterableOnce is a very bad idea because it's the same trap as trying to introduce an interface UnmodifiableList as subtype of List. Rémi
