RFC: draft API for JEP 269 Convenience Collection Factories (original) (raw)

Stephen Colebourne scolebourne at joda.org
Sat Oct 17 08:43:38 UTC 2015

On 14 October 2015 at 18:56, Kevin Bourrillion <kevinb at google.com> wrote:

Note that we have empirically learned through our Lists/Sets/Maps factory classes that varargs factory methods for mutable collections are almost entirely useless.

Having taken a few days to think it over, I reluctantly think that Kevin is right. Particularly as static methods on classes are inherited, as Remi says. If someone needs a mutable one, they can simply write:

new ArrayList<>(List.of(z, b, c))

Adding immutable implementations just on the interfaces seems like a reasonable balancing point, and provides more API room to add the IntFunction version I mentioned ;-)

As a side note, a really nice language change would be to deprecate the ability to refer to static methods from subclasses or instance variables in the JLS.

Stephen

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