JEP 269: Convenience Factory Methods for Collections (original) (raw)

Chris Hegarty chris.hegarty at oracle.com
Wed Oct 7 10:10:16 UTC 2015

On 7 Oct 2015, at 10:30, Stephen Colebourne <scolebourne at joda.org> wrote:

On 7 October 2015 at 01:13, Stuart Marks <stuart.marks at oracle.com> wrote:

My question is, is this enough of a problem that we should allow nulls in these collections? I would prefer not to do this, but if there is evidence that this would be a mistake, I'd like to hear it.

And if disallowing nulls will cause developers to create things like Map<K,Optional>, are we ok with that, and are developers ok with that? Given what we know now vs when the collections library ws created, I think it would be a mistake to allow nulls. Developers that desperately want null in there have other mechanisms to achieve that, not just Optional.

I agree with this. These are, after all, “just convenience” methods, there are other ways if null is required. I do not see any compelling reason for allowing null, given the type of use case these methods are trying address, collections and maps with small numbers of elements.

I too would argue against Optional in collections, at least until value types exist, but thats a social discussion, not one that can be controlled.

Stephen

-Chris.

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