RFR: 8179918: EnumSet spliterator should report SORTED, ORDERED, NONNULL [v3]

[Viktor Klang]

On Tue, 2 Dec 2025 09:09:35 GMT, Patrick Strawderman <duke at openjdk.org> wrote:

>> I noticed that the Spliterator for EnumSet does not report SORTED, ORDERED, or NONNULL characteristics, all of which are inherent to API of EnumSet. I found there's an existing ticket for this as well.
>> 
>> The ticket also mentions optimized `forEach`, etc, which I presume means avoiding the default implementation that uses the iterator and just iterating over the bitset directly; I can add that here or perhaps in a follow up if it's still deemed worthwhile.
>
> Patrick Strawderman has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Add unit test

test/jdk/java/util/EnumSet/EnumSetSpliteratorTest.java line 79:

> 77:         assertTrue(spliterator.hasCharacteristics(Spliterator.SORTED), "Missing SORTED");
> 78:         assertTrue(spliterator.hasCharacteristics(Spliterator.ORDERED), "Missing ORDERED");
> 79:         assertTrue(spliterator.hasCharacteristics(Spliterator.NONNULL), "Missing NONNULL");

Thanks for adding the test. I think it makes sense to check the `enumSet.spliterator().characteristics()` being exactly `DISTINCT | SORTED | ORDERED | NONNULL` (since this test otherwise would still pass if further characteristics are added).

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PR Review Comment: https://git.openjdk.org/jdk/pull/28568#discussion_r2581832277