RFR: 8329644: Discuss expected visitor evolution patterns in javax.lang.model.util

[Pavel Rappo]

On Wed, 17 Apr 2024 15:23:35 GMT, Jan Lahoda <jlahoda at openjdk.org> wrote:

> We mark the preview-related entry points of the javax.lang.model and Trees API with `@PreviewFeature(..., reflective=true)`, and this then produces warnings like:
> 
> ```
> $ javac  /tmp/TestPreview.java
> /tmp/TestPreview.java:3: warning: [preview] COMPONENT_LOCAL_VARIABLE is a reflective preview API and may be removed in a future release.
>         System.err.println(javax.lang.model.element.ElementKind.COMPONENT_LOCAL_VARIABLE);
>                                                                ^
> 1 warning
> ```
> 
> I.e. the potential removal is not without a warning. (The difference between "reflective" and non-"reflective" Preview API is that the reflective API can be used without `--enable-preview`.)

Ah! I didn't notice that `*(Visitor|Scanner)*Preview` classes were annotated with `@PreviewFeature(feature=PreviewFeature.Feature.LANGUAGE_MODEL, reflective=true)` because the diffs _in_ the doc comment didn't contain them. Good to know this has been taken care of, thanks! But what about constants and methods this PR proposes to add to `ElementKind`, `ElementVisitor`, and the likes? How does that work?

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PR Comment: https://git.openjdk.org/jdk/pull/18804#issuecomment-2061611092