Most current Proxy-as-implemented test suite?

Tom Van Cutsem at
Fri May 3 11:24:59 PDT 2013

Hi David,

2013/5/2 David Bruant <bruant.d at>

>  IIRC, trying to change the design of harmony:proxies to be able to
> represent these (probably started at [1], also motivated by arrays length
> property) led to listing invariants (eternal/momentary) and then led to the
> idea of a per-proxy storage to remember which invariants should be
> enforced. But for the degenerate case of a forwarding proxy (frozen
> object), this would have resulted in pretty much duplicating the needed
> memory. One fold for the object itself, the other for the invariant storage.
> Direct proxies emerged out of the idea of merging the target from the
> forwarding proxy use case and the "invariant storage".

Yes, that's a fairly accurate history.

> In any case, harmony:proxies have limitations apparently inherent to their
> design, hence moving away from them.

The limitation was indeed that they couldn't represent
non-extensible/non-configurable invariants without some extra hidden
storage. Direct proxies make that storage explicit as the target object.

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <>

More information about the es-discuss mailing list