Long-awaited State of the Values docs

[Brian Goetz]

Crud, wrong mailing list.

On 12/6/2019 11:54 AM, Brian Goetz wrote:
> I have posted the first two sections of "State of Valhalla" at:
>
> http://cr.openjdk.java.net/~briangoetz/valhalla/sov/01-background.html
> http://cr.openjdk.java.net/~briangoetz/valhalla/sov/02-object-model.html
>
> This reflects numerous simplifications of the language and VM model, 
> following the discussions that we started at JVMLS this year.  We have 
> been able to eliminate the multiple painful dualities (LV vs QV, 
> zero-default vs null-default, T vs T?) by replacing them with a much 
> simpler relationship between an inline class and a companion interface.
>
> The other major AHA buried in this document is the realization that 
> the language and VM models need not align 100%.  LWorld is the right 
> VM model, but we can use it as a _translation target_ rather than our 
> language model.  This allows the primitives to blossom into full 
> inline classes.  In the new world, we have inline classes and identity 
> classes, primitives are mostly just inline classes, and the 
> relationship between inlines and identity classes is isomorphic to the 
> current relationship between primitives and classes.
>
> There's a lot to absorb here, so I suggest you read it a few times and 
> then bring your questions.
>
>