Proposal: Abstract References

Andreas Rossberg rossberg at
Tue Oct 21 23:59:13 PDT 2014

On 21 October 2014 22:31, Mark S. Miller <erights at> wrote:
>> in saying that [weak maps] are not designed to work efficiently in that manner.
> Actually, they are. The problem is that initial implementations date from
> before we appreciated the need for the transposed representation. The best
> thing TC39 can do for the future of WeakMaps is to proceed assuming the
> transposed representation.

While I sympathise, let me clarify that this still remains a
conjecture. AFAIK, nobody has proved it empirically in a JS
implementation yet, we don't know in detail how complex such an
implementation would be, and what side effects it might have on
general performance (e.g., via added polymorphism). It's most likely
not as easy or as clear a win as you may think it is.


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