[cap-talk] Petnames versus E-order with ocaps

[Karp, Alan H]

MarkM wrote:
> 
> So a petname system built in E would be a 1-to-1 map, implemented by a
> pair of normal maps, between names and settled references. If Bob is
> not sure x is yet settled, then (ignoring for the moment the
> difference between settled and fulfilled), Bob should use a when block
> to guard his logic for looking up/ assigning the reference a pet name
> until it is resolved:
> 
> when (x) -> {
>     # ... can safely assume x is fulfilled here ...
>     # ... so give/retrieve petname and display ...
> } catch ex {
>     # ... assume x was broken ...
> }
>
I hadn't realized that Bob gets a promise for Carol that settles only after preceding messages from Alice to Carol have arrived.  Your example sounds like a lambda name system in which Bob can choose to use a single name independent of the source of the reference to act as a petname but can retain the underlying lambda name.  In a pure petname system, Bob would see one petname for every reference that tests == to this promise.  Otherwise we give up the promise pipelining by sending messages to the promise, right?  The petname would change when the promise settles to Carol if Bob already had a reference to Carol.  Strange but workable, I think.  

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Alan Karp
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Virus Safe Computing Initiative
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