AbstractList etc. functionality as interfaces with default methods?

Remi Forax forax at univ-mlv.fr
Thu May 14 13:24:53 UTC 2015



On 05/14/2015 03:05 PM, Brian Goetz wrote:
>>> Not only is there a problem with modCount, but also with equals/hashCode/toString.  You can’t define these Object methods in an interface.
>> They could be defined as static methods to delegate to. From API consistency perspective, we have for example the following static methods on primitive wrapper classes:
> Right.  We considered this during Lambda, but by the time we got here, we concluded that this was mostly trading one downside for another.  It seemed overwhelmingly likely that people would forget to override equals/hashCode/toString in this case, and create collections that violated the contract.
>

The other problem is that it creates ambiguous method references,
if you have a class or an interface like:
class A {
   public static int hashCode(A a) { ... }
}

A::hashCode is ambiguous.

cheers,
Rémi




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