Superinterface.this.method()

[maurizio cimadamore]

On 18-Dec-11 3:12 AM, bitter_fox wrote:
> interface A
> {
>      public void a() default
>      {
>          System.out.println("A");
>      }
> }
>
> class B implements A
> {
>      public void a()
>      {
>          A.this.a(); // "A" or StackOverflowError?
>      }
> }
Hi
The syntax for A.this.a() should be disallowed, as, according to the 
JLS, A should be an enclosing class (which is not the case here). I 
think it's reasonable to expect that the final version of the compiler 
would give an error similar to the one you get today with JDK 5/6/7 if 
you remove the default from A and you make B abstract - the compiler 
will complain because 'A is not an enclosing class'.

What you want here is:

A.super.a()

as described in the latest State of the Lambda draft [1].
The semantics of A.this/A.super where A is an interface with extension 
methods is still to be correctly implemented by the compiler - so I 
wouldn't rely much on what is/isn't accepted by the compiler as of today.

Thanks
Maurizio

[1] - http://cr.openjdk.java.net/~briangoetz/lambda/lambda-state-4.html