Sep 27 meeting notes

Brendan Eich brendan at
Thu Sep 29 11:48:04 PDT 2011

On Sep 29, 2011, at 7:46 PM, Allen Wirfs-Brock wrote:

> Just pointing out that not using const properties doesn't mean that the need for a const read barrier on every property access. Without doing closed world whole program analysis every property [[Get]] has to account for the possibility that it may be accessing an uninitialized const property.  It may be that an implementation can find a way to fold this check into an initial fast-path guard.

That analysis/guard must exist due to getters already.

>  By introducing such a semantics we are adding to the complexity of every [[Get]].
> This is different form the read barrier for lexical const declaration which can be lexical name specific within a lexically bounded scope.



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