d at domenic.me (2015-01-28T19:10:57.439Z)
On Tue, Jan 27, 2015 at 5:53 PM, Boris Zbarsky <bzbarsky at mit.edu> wrote: > For [[DefineOwnProperty]], are we basically talking about changing step 1 > to: > > 1) If the [[Configurable]] field of Desc is present and > Desc.[[Configurable]] is false, then throw a TypeError exception. > > while keeping everything else as-is, Exactly correct. I didn't realize until reading your reply is that this is all that's necessary -- that it successfully covers all the cases I was thinking about without any further case division. > ? If so, that's certainly a change that is much more likely to be > web-compatible... Good! It certainly takes care of the one concrete breakage we know about so far.
On Tue, Jan 27, 2015 at 5:53 PM, Boris Zbarsky <bzbarsky at mit.edu> wrote: > On 1/27/15 4:44 PM, Mark S. Miller wrote: > >> Since the WindowProxy is not a Proxy, or more relevantly, even if it >> were a Proxy, the underlying Window is not its target, we can even do >> the following: >> >> When the WindowProxy sees the defineProperty with the omitted >> "configurable:" and determines that the underlying Window does not >> already have this property. WindowProxy can even preserve the >> unwarranted intent expressed in the comment by actually defining a >> *non-configurable* own property on the Window itself. However, the >> behavior of the WindowProxy is not observably different than our Proxy >> example: It acts as if it created a configurable own property on the >> WindowProxy of this same name, and then proceeds with the normal >> defineProperty behavior, which preserves that alleged configurability. >> > > I'd like to understand better the suggestion here, because I'm not sure > I'm entirely following it. Specifically, I'd like to understand it in > terms of the internal methods defined by <https://github.com/domenic/ > window-proxy-spec>. > > Presumably you're proposing that we keep all of that as-is except for > [[DefineOwnProperty]], right? > > For [[DefineOwnProperty]], are we basically talking about changing step 1 > to: > > 1) If the [[Configurable]] field of Desc is present and > Desc.[[Configurable]] is false, then throw a TypeError exception. > > while keeping everything else as-is, Exactly correct. I didn't realize until reading your reply is that this is all that's necessary -- that it successfully covers all the cases I was thinking about without any further case division. > as opposed to the behavior I'd understood we were aiming for, which was: > > 1) If the [[Configurable]] field of Desc is not present or > Desc.[[Configurable]] is false, then throw a TypeError exception. > ? If so, that's certainly a change that is much more likely to be > web-compatible... Good! It certainly takes care of the one concrete breakage we know about so far. -- Cheers, --MarkM -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mail.mozilla.org/pipermail/es-discuss/attachments/20150127/d5292b99/attachment.html>