RFC: draft API for JEP 269 Convenience Collection Factories

Remi Forax forax at univ-mlv.fr
Fri Oct 16 23:17:52 UTC 2015

The other reason I see to avoid methods of on impelmentations is that as i've already said, Java allows to inherits static methods defined on class so adding a method of() on ArrayList will allow people to use of on a subclass of HashMap/ArrayList but did get the expected object, by example, LinkedHashMap.of() will return a HashMap.

so +1 to have methods of() only on interfaces.


----- Mail original -----
> De: "John Rose" <john.r.rose at oracle.com>
> À: "Kevin Bourrillion" <kevinb at google.com>
> Cc: "core-libs-dev" <core-libs-dev at openjdk.java.net>
> Envoyé: Mercredi 14 Octobre 2015 22:46:40
> Objet: Re: RFC: draft API for JEP 269 Convenience Collection Factories
> On Oct 14, 2015, at 10:56 AM, Kevin Bourrillion <kevinb at google.com> wrote:
> > Anyway, since we created these methods, they became an attractive nuisance,
> > and thousands of users reach for them who would have been better off in
> > every way using an immutable collection. Our fondest desire is to one day
> > be able to delete them. So, obviously, my strong recommendation is not to
> > add these to ArrayList, etc.
> I agree with Kevin's warning here.  Please, (1) make the immutable version
> easy to get (List.of not ImmutableList.of), and require users to
> thoughtfully opt into mutability (new ArrayList not ArrayList.of).
> — John

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