where are all the objects?

[John Rose]

I could live with this.  It doubles down on “everything is an 
object”, and something might be modeled separately as a non-object a 
“value”, is just a sub-kind of object, hence “value object”.

So the real big divide is not between objects and non-objects, but 
between value-objects and identity-objects.  And, as befits a world 
where everybody is in the object family, it’s a gentle divide, since 
values and identities have lots in common: references, methods, `extends 
Object`.  Meanwhile, the symmetric difference of value and identity 
contains, on the one side, the option for “direct” storage (whatever 
that means; it’s vague but real), and on the other side mutability, 
etc.

A couple more comments below:

On 11 Aug 2022, at 13:08, Brian Goetz wrote:

> …So:
>
>  - classes have instances, which are objects
>  - some classes are identity classes and some are value classes
>    - instances of identity classes have identity, are called 
> identity objects
>    - instances of value classes have no identity, are called value 
> objects
>  - any objects can be the target of an object reference
>    - Polymorphic types like Object or Runnable may refer to identity 
> or value objects
>  - value objects can be represented/stored/manipulated directly as 
> well, like our old friend int
>  - legacy primitive are value objects now!
>    - everything is an object
>  - The type P.ref is a reference type, it consists of references to 
> instances of P

Tedious pedant is tediously pedantic:  or `null`.

>  - The type P.val is a value type, it consists of instances of P, 
> which are value objects
>  - Integer is a reference type, int is a value type

Maybe emphasize the linkage:  `Integer.val`, `int.ref` are a aliases for 
`int` and `Integer`

>
> This isn't much different from the previous "VAO" presentation, other 
> than being more explicit about saying "value objects" rather than just 
> values --
> does that help at all?

I think it does.  Saying “values” unqualified suggests (misleadingly 
for VAO) that not everything is an object.
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