RFR: 8343251: Facelift for Type and AnnotatedType specifications [v7]

[Chen Liang]

On Thu, 5 Dec 2024 17:54:34 GMT, Chen Liang <liach at openjdk.org> wrote:

>> The Type and AnnotatedType hierarchies have been enigmatic to new users: users have no clue how to categorize arbitrary type objects, when it is safe to cast to more specific types, and the exact conditions for method contracts.
>> 
>> A manifest is [JDK-8306039](https://bugs.openjdk.org/browse/JDK-8306039), where people are massively confused by the conditions for `ParameterizedType::getOwnerType` to return `null`.
>> 
>> To fix these problems, I consulted the JLS, used some terms from there and added JLS links to make the definitions concise and accurate.
>> 
>> Here are some actions:
>> 1. Add section for hierarchy overview for both Type and AnnotatedType
>> 2. Specify the underlying type for different AnnotatedType subinterfaces
>> 3. Define "inner member class" for `getOwnerType`, and refer to it in `AnnotatedType::getAnnotatedOwnerType`.
>> 4. Improve the specification for `ParameterizedType::getActualTypeArguments` to note the existence of owner types; also for annotated version
>> 5. Minor improvements to `ParameterizedType::getRawType`
>> 6. Move the equals specification for `ParameterizedType` to the actual `equals` method.
>> 
>> ApiDiff: https://cr.openjdk.org/~liach/apidiff/types-facelift/java.base/java/lang/reflect/package-summary.html
>> Javadoc: https://cr.openjdk.org/~liach/javadoc/types-facelift/java.base/java/lang/reflect/package-summary.html
>> 
>> Please review the associated CSR as well.
>
> Chen Liang has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Problems with owner type, kevin suggestions

This attracts fewer reviews because the APIs are already widely used, but these improvements still clarify a lot of confusions and establish clear relations from the API models to the JLS.

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PR Comment: https://git.openjdk.org/jdk/pull/19977#issuecomment-2563463492