JDK 9 request for specification changes of JDK-8032230: Enhance javax.a.p.RoundEnvironment after repeating annotations

[Jan Lahoda]

On 18.5.2016 22:26, joe darcy wrote:
> Hi Jon,
>
> On 5/18/2016 1:05 PM, Jonathan Gibbons wrote:
>> It's sad to see the preference given to the more intellectually
>> suspect of the two possibilities.
>
> Agreed, sad but pragmatic.

Would it make sense to use varargs instead of a Set? If we assume the 
typical use will be something like:
round.getElementsAnnotatedWithAny(annotation, containerAnnotation)

it might be more convenient to have the method take a vararg than a Set 
(and would avoid the problem with the erasure clash as another benefit).

Jan

>
>>
>> It would be nice to see the nice name given to the intellectually
>> superior of the possibilities (i.e AnnotationMirror) and then figure
>> out how to deal with the other case.
>
> How about the name "getElementsAnnotatedWithAny" for both variations?
> That potentially avoids confusion over whether or not the elements have
> to be modified with any of the annotations or all of them.
>
>>
>> As well as the possibility of another method name, have you ever
>> considered the possibility of conversion functions of
>> Elements/Types/<something-new>  that can convert between (collection
>> of) Annotation and (collection of) AnnotationMirror?
>
> Internally, for the existing methods javac does convert the Class-based
> version to the TypeElement based version, but I don't think we want the
> specification to require that.
>
> Thanks,
>
> -Joe
>
>>
>> -- Jon
>>
>> On 05/18/2016 12:55 PM, joe darcy wrote:
>>> Hello,
>>>
>>> Please review the patch below which proposes a new method to address
>>>
>>>     JDK-8032230: Enhance javax.a.p.RoundEnvironment after repeating
>>> annotations
>>>
>>> At present, this is just a review of the specification of the default
>>> method in the interface and *not* a more optimized implementation in
>>> the javac RoundEnvironemnt implementation (and not any tests that
>>> would be needed for the new functionality).
>>>
>>> Note that the bug proposes adding two methods
>>>
>>>     RoundEnvironment.getElementsAnnotatedWith(Set<Class<? extends
>>> Annotation>> s)
>>> RoundEnvironment.getElementsAnnotatedWith(Set<AnnotationMirror> s)
>>>
>>> but these methods would clash since their erasure is the same. *sad
>>> tromphone*
>>>
>>> Therefore, I'm only proposing to add the Class-based variant since
>>> that one is the more commonly used of the two.
>>>
>>> Thanks,
>>>
>>> -Joe
>>>
>>>
>>> +    /**
>>> +     * Returns the elements annotated with any of the given annotation
>>> +     * types.
>>> +     *
>>> +     * @apiNote This method may be useful when processing repeating
>>> +     * annotations by looking for an annotation type and its
>>> +     * containing annotation type at the same time.
>>> +     *
>>> +     * @implSpec The default implementation of this method creates an
>>> +     * empty result set, iterates over the annotations in the argument
>>> +     * set calling {@link #getElementsAnnotatedWith(TypeElement)} on
>>> +     * each annotation and adding those results to the result
>>> +     * set. Finally, the contents of the result set are returned as an
>>> +     * unmodifiable set.
>>> +     *
>>> +     * @param annotations  annotation type being requested
>>> +     * @return the elements annotated with the given annotation types,
>>> +     * or an empty set if there are none
>>> +     * @throws IllegalArgumentException if the any elements of the
>>> +     * argument set do not represent an annotation type
>>> +     * @since 9
>>> +     */
>>> +    default Set<? extends Element>
>>> getElementsAnnotatedWith(Set<Class<? extends Annotation>> annotations){
>>> +        HashSet<Element> result = new HashSet<>();
>>> +        for (Class<? extends Annotation> annotation : annotations) {
>>> + result.addAll(getElementsAnnotatedWith(annotation));
>>> +        }
>>> +        return Collections.unmodifiableSet(result);
>>> +    }
>>>
>>
>