A simpler model for repeating annotations

[Alex Buckley]

Sharing a single containing annotation type between multiple repeating 
annotation types is not unreasonable. However, it fundamentally relies 
on annotation subtyping, which was not in scope for JEP 120.

Alex

On 1/8/2013 3:17 AM, Ali Ebrahimi wrote:
> Hi Alex,
> I think, I'm late to list.
> The following is just my 2 cent suggestion to your proposal.
>
> 1) Introduce AnnotationContainer annotation in java.lang package (java
> se 8 ) as default container for repeating annotations:
>
> @interface AnnotationContainer{ Annotation[] value(); }
> (relax rules of jls 9.6.1 to include Annotation (class) type)
>
> 2) Modify Repeatable annotation:
> @interface Repeatable{ Class<? extends Annotation> value() default
> AnnotationContainer.class; }
>
> with 1, 2 in mind we have one standard default container annotation for
> all repeating annotations that don't specify containing annotation. This
> allows to package all repeating annotations in one container annotation
> and reduce static and dynamic footprint. In other side, developer don't
> need to introduce one containing annotation for each repeating
> annotations, this also reduce number of class files and makes this
> feature of java 8 user friendly for developer. developer just need
> annotate repeating annotations with Repeatable annotation.
>
> example:
>
> @Repeatable
> @interface Foo { int value(); }
>
> @Repeatable
> @interface Bar{}
>
> @Repeatable(AliContainer.class)
> @interface Ali{ String value();}
>
> @interface AliContainer{ Ali[] value(); }
>
>
> @Foo(1) @Foo(2) @Bar @Bar @Ali("java lover") @Ali("Flying on the Clouds")
> class A {}
>
> in class file:
>
> @AnnotationContainer({@Foo(1), @Foo(2), @Bar, @Bar})
> @AliContainer({@Ali("java lover"), at Ali("Flying on the Clouds")})
> class A {}
>
>
> Regards,
> Ali Ebrahimi