[foreign-memaccess+abi] RFR: 8291639: Improve the ability to visualize a MemorySegment in human readable forms [v24]

[Gavin Ray]

On Tue, 5 Sep 2023 11:46:25 GMT, Per Minborg <pminborg at openjdk.org> wrote:

>> This PR proposes to add a "Record Mapper" that allows `MemorySegment` instances to be projected onto `Record` types given `GroupLayout` instances.
>> 
>> Here is a simple example of how to use the mapper:
>> 
>> 
>>     private static final GroupLayout POINT_LAYOUT = MemoryLayout.structLayout(
>>             JAVA_INT.withName("x"),
>>             JAVA_INT.withName("y"));
>> 
>>     MemorySegment segment =  MemorySegment.ofArray(new int[]{3, 4});
>> 
>>     Point point = POINT_LAYOUT.recordMapper(Point.class)
>>           .apply(segment); // Point[x=3, y=4]
>> 
>> 
>> I think the implementation can be improved later, for example by de-duplicating handling of arrays and maybe add recursive "un-pealing" of multidimensional arrays.
>
> Per Minborg has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 57 commits:
> 
>  - Merge foreign-memaccess+abi
>  - Update src/java.base/share/classes/java/lang/foreign/GroupLayout.java
>    
>    Co-authored-by: ExE Boss <3889017+ExE-Boss at users.noreply.github.com>
>  - Change to TypeMapper
>  - Use Stream rather than Spliterator
>  - Rewrite javadoc
>  - Rename benchmark and use standard values
>  - Add test for recursive component use
>  - Rewrite class doc
>  - Clean up code
>  - Eliminate duplicate code
>  - ... and 47 more: https://git.openjdk.org/panama-foreign/compare/4473ef24...555a15ad

I am so unbelievably hyped for this 🙌

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PR Comment: https://git.openjdk.org/panama-foreign/pull/833#issuecomment-1707185526