On May 16, 2011, at 12:18 AM, Erik Corry wrote: > 2011/5/16 Brendan Eich <[email protected]>: >> On May 16, 2011, at 12:01 AM, Brendan Eich wrote: >> >>> On May 15, 2011, at 11:55 PM, Erik Corry wrote: >>> >>>> 2011/5/16 Brendan Eich <[email protected]>: >>>>> Not if the object is frozen. >>>> >>>> That shouldn't prevent you adding private names. See earlier message >>>> in this thread. >>> >> >>> Frozen means [[Extensible]] is false, so you can't add any properties, ... >> >> I'll go further: frozen means the implementation should be free to move the >> object and anything associated with its shallow-frozen key/value state into >> read-only memory, so the full force of 50-year-plus OS and hardware MMU >> protection can ensure [[Extensible]] really is false. > > I think this would also preclude the most efficient implementation of > Weak Maps. In fact I have a hard time seeing how you would GC weak > maps at all under these conditions.
Why, because GC metadata has to go in the same page as the frozen object that might be a key in a weak map? Weak maps are in Firefox nightlies. We're playing with page protection too (not for freezing, yet). This seems like a dare, but it also seems to be dodging my point in replying again: that private names cannot be used to extend frozen objects in the "[[Extensible]] = true" sense of the spec. /be _______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
