Nestmate same-package check

John Rose john.r.rose at
Thu Apr 20 03:08:08 UTC 2017

On Apr 19, 2017, at 7:46 PM, Brian Goetz <brian.goetz at> wrote:
>> The way I visualize this is that each newly arrived class
>> checks in with its host.  If the name is on the list, it gets in.
> Right, and if it's not on the list?  Does it get assigned its own nest-of-one, or do we reject the class?  I would expect the former? (If you show up at a party and you're not on the invite list, you can still have your own party, just not here.)

Hmm…  I assumed you would fail the load.  Let's see…

Failing the load leads to a harsh, "fast-fail" binary compatibility policy.

It specifically affects left-over class files from a previous compile.

If you load a leftover by accident, it will point to either a non-existent, or a newly-compiled host that won't acknowledge it.

Is there a binary compatibility case for loading leftovers like that?

I kind of think no:  It's always a bug when files from previous compilations stick around.

Let's fail them instead of try to load them in some party-of-one recovery mode.

Do you have a different use case in mind where a recovery mode is useful?

— John

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