Default value for date/time

[John Rose]

On May 7, 2018, at 4:47 PM, John Rose <john.r.rose at oracle.com> wrote:
> 
>  - make all-zero LD return "LocalDate(null)" for toString
>  - make all-zero LD throw NullValueException for all other access methods
> 
> (Where NVE is a relative of NPE.)

I can't resist touching up this bikeshed!

 - make all-zero LD return "LocalDate.default" for toString
 - make all-zero LD throw DefaultValueException for all other access methods

(Where DVE is a relative of NPE.)

Note that DVE is an opt-in exception that the value type designer
*may* use if the value type has no useful default value, and wants
to flag accesses to that value.

— John