RFR: 8366178: Implement JEP 526: Lazy Constants (Second Preview) [v26]

[Maurizio Cimadamore]

On Mon, 17 Nov 2025 09:32:02 GMT, Per Minborg <pminborg at openjdk.org> wrote:

>> Implement JEP 526: Lazy Constants (Second Preview)
>> 
>> The lazy list/map implementations are broken out from `ImmutableCollections` to a separate class.
>> 
>> The old benchmarks are not moved/renamed to allow comparison with previous releases.
>> 
>> `java.util.Optional` is updated so that its field is annotated with `@Stable`.  This is to allow `Optional` instances to be held in lazy constants and still provide constant folding.
>
> Per Minborg has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 125 commits:
> 
>  - Merge branch 'master' into lazy-constants
>  - Merge master
>  - Fix tests and improve docs
>  - Remove inner classes in LazyList
>  - Fix TOC TOU issue
>  - Improve documentation for List and Map factories
>  - Improve doc details
>  - Improve text for hashCode()
>  - Refine text about reachabilit of the contents
>  - Align doc links for get()
>  - ... and 115 more: https://git.openjdk.org/jdk/compare/69e30244...3c26e095

src/java.base/share/classes/java/lang/LazyConstant.java line 244:

> 242:      * <p>
> 243:      * In other words, equals compares the identity of this lazy constant and {@code obj}
> 244:      * to determine equality. Hence, two lazy constant with the same contents are

Suggestion:

     * to determine equality. Hence, two lazy constants with the same contents are

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PR Review Comment: https://git.openjdk.org/jdk/pull/27605#discussion_r2533674027