On Mon, 9 Aug 2021 12:28:23 GMT, CC007 <github.com+5381337+cc...@openjdk.org>
wrote:
> create Streamable and ParallelStreamable interface and use them in Collection
> and Optional
With modern java, you can always create a `Streamable` on your own (and have
specifications/documentations that a simple `Supplier` lacks) and implement it
like:
public interface Streamable<T> {
Stream<T> stream();
static Streamable<T> ofIterable(Iterable<T> iterable) {
return () -> StreamSupport.stream(iterable.spliterator(), false);
}
}
The lack of such an interface in the JDK is not really a problem.
> Are you suggesting that there are deeper architectural issues with the
> hierarchy-heavy collection stack?
I am saying that your sample project has unnecessarily many interfaces for your
collection model, where many of them have little virtue on their own. This
interface mash is susceptible to accidentally introducing unwanted features
into the hierarchy and having method or specification clashes for
implementation.
Looking back on identifying efficiently streamable objects, people can usually
find efficient streams by the method return types. Your interface doesn't allow
people to identify `BufferedReader.lines()` as an efficiently streamable
target, for instance.
In addition, I think the main purpose of `Optional.stream()` is to allow using
it in stream flatmapping than to promote stream creation with optionals.
-------------
PR: https://git.openjdk.java.net/jdk/pull/5050
