2011/8/15 Cameron McCormack <cam@mcc.id.au> > On 15/08/11 8:58 PM, Tom Van Cutsem wrote: > >> So, to future-proof if this strawman is accepted, I think it's best to >> let existing |defineProperty| traps |return true;|. >> > > By that do you mean interpret an undefined return value as meaning "don't > throw"? Sounds reasonable. > No, that's not what I meant. We could consider it, but then the same meaning should apply to the 'set' and 'delete' traps. What I meant was that existing Proxy code (in which defineProperty doesn't need to return a boolean success value) is not upwards-compatible with this strawman. If a defineProperty trap does not return a value (or returns undefined), under this strawman that indicates a failed defineProperty invocation, which is most probably not what the original code intended. If proxy authors want to anticipate acceptance of this strawman, they can do so by having defineProperty traps |return true;| already. We need to discuss this change at the next TC39 meeting, but I don't currently see any reason why it would not be accepted into the proxies proposal. Cheers, Tom
Received on Tuesday, 16 August 2011 11:03:17 UTC