Valhalla Minimal Value Types review invitation

John Rose john.r.rose at
Wed Apr 12 10:09:00 UTC 2017

On Apr 11, 2017, at 3:38 PM, Karen Kinnear <karen.kinnear at> wrote:
> Summary of requested modifications from early prototyping experiments. Followed by action items.

Thanks, Karen.  It is very, very helpful to have all these points rolled up like this.

I just updated the posted proposal to respond to your points 1 to 13.

I should get through the rest of the points this week.

There are only two places so far where I have had to disagree slightly.

> On Apr 11, 2017, at 3:38 PM, Karen Kinnear <karen.kinnear at> wrote:
> 6. Restrictions on the POJO:
>    8. May not inherit from any interfaces

It is useful and harmless for the POJO to implement interfaces.
In the new section "Boxing, unboxing, and borrowing" I touch on this.

> 12. vdefault/vwithfield
>     restrictions: vdefault only within constructor, vwithfield only within the class
>      note: temporary issue: since DVT has no constructor or other methods, must allow 
>      vdefault also within the DVT and vwithfield across VCC/DVT pairs.
>      note: a value type array allows default value to escape

I added discussion of restrictions on these bytecodes.
Bottom line:  There is no reason to restrict vdefault.

Talk to you soon!

— John

P.S. The referenced file and its source is enclosed for archiving and convenient access.

More information about the valhalla-spec-observers mailing list