Mark S. Miller
erights at google.com
Sat Nov 3 18:15:32 PDT 2012
WeakMap.has is fine (and already speced) because the presence of the
association depends on the key. However, if the key is garbage, a strong
ref to the value does not preserve the association in the map.
On Sat, Nov 3, 2012 at 6:05 PM, Brendan Eich <brendan at mozilla.org> wrote:
> Is this true? I can see how enumeration and size would leak the GC
> schedule, but to test has or contains, you need a strong ref, which means
> the key or value cannot yet be garbage. If you have the capability, there's
> no non-determinism. What am I missing?
> Allen Wirfs-Brock wrote:
>> On Nov 3, 2012, at 4:53 PM, Mark S. Miller wrote:
>> On Fri, Nov 2, 2012 at 5:26 PM, Allen Wirfs-Brock <allen at wirfs-brock.com<mailto:
>>> allen at wirfs-brock.com>**> wrote:
>>> Also any reason contains should be provided for WeakMap? I not
>>> seeing why it shouldn't be there too.
>>> The set of values actually contained by the WeakMap at any moment is
>>> non-deterministic, depending on the scheduling of gc. But this
>>> non-determinism is non-observable. WeakMap.contains would make it
>> es-discuss mailing list
>> es-discuss at mozilla.org
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