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 <bren...@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? > > /be > > 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 >> <al...@wirfs-brock.com<mailto: >>> al...@wirfs-brock.com>**> wrote: >>> >>> >>> Also any reason contains should be provided for WeakMap? I not >>> seeing why it shouldn't be there too. >>> >>> >>> Yes! >>> >>> 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 >>> observable. >>> >> >> >> yup >> >> >> >> >>> -- >>> Cheers, >>> --MarkM >>> >> >> ______________________________**_________________ >> es-discuss mailing list >> es-discuss@mozilla.org >> https://mail.mozilla.org/**listinfo/es-discuss<https://mail.mozilla.org/listinfo/es-discuss> >> > -- Cheers, --MarkM
_______________________________________________ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss
