Mark S. Miller (2015-06-17T03:05:40.000Z)
d at domenic.me (2015-07-07T01:36:50.903Z)
If WeakSets were iterable, then any such optimization would be observable and therefore disallowed. It is precisely the unobservability of GC that give us the freedom to engage in such transparent optimizations. The platform can certainly provide itself with internal iterable WeakSet-like collections for its own internal and unobservable purposes. If we're talking about an unobservable optimization internal to the platform, then why is the non-iterability of externally visible WeakSets an issue? Is there currently some observability issue I am missing?