Combine StreamSupport.stream/parallelStream?

[Paul Sandoz]

On Jun 27, 2013, at 10:43 PM, Brian Goetz <brian.goetz at Oracle.COM> wrote:

> A possible minor API cleanup:
> 
> For each pair of low-level methods stream() and parallelStream() in StreamSupport, we could combine these into a single method that takes an additional boolean isParallel argument.  This matches the underlying implementation they call anyway, and simplifies callers like concat, which now does:
> 

Seems a reasonable thing to do.

The current approach matches nicely that on collection:

    default Stream<E> stream() {
        return StreamSupport.stream(spliterator());
    }

    default Stream<E> parallelStream() {
        return StreamSupport.parallelStream(spliterator());
    }

But that is actually a minority of usage. Most use of StreamSupport is for the stream() methods.

We could get away with just one less method per type for the supplying variant:

    public static <T> Stream<T> stream(Spliterator<T> spliterator)
    public static <T> Stream<T> stream(Spliterator<T> spliterator, boolean isParallel)
    public static <T> Stream<T> stream(Supplier<? extends Spliterator<T>> supplier,
                                      int characteristics, boolean isParallel)

Paul.