Dmitry said it all, let me just add that we expect this to only delay the availability of classes in Chrome for one extra release cycle (i.e., ~6 weeks).
/Andreas On 8 January 2015 at 16:09, Dmitry Lomov <[email protected]> wrote: > A few weeks ago, yet in 2014, we have announced shipping ES6 classes in V8 > [1]. > > Our implementation was mostly following current ES6 draft specification. > However, as discussed on the intent-to-ship thread [1], we have found > several aspects of the specification problematic, namely subclassing of > exotic objects, in particular DOM objects. > > Therefore what we were shipping at that time was a *conservative subset* > of ES6 specification. > > As I stated in my intent-to-ship email, we were planning to work with > involved parties to resolve these issues. I am happy to report that that > work has now come to fruition. TC39 ECMAScript Committee turned a > sympathetic ear to our difficulties (echoed, as it turns out, by other > browser vendors), and intense technical discussion ensued over the last few > weeks among committee members to resolve them. As a result of this > discussion, the committee arrived at a revised design for subclassing ES6 > classes that successfully addresses those problematic aspects. Overview of > that amended design is at [2]. The committee expressed confidence that this > amended design can be completed and put into the spec in ES6 timeframe. > > We are very pleased with these developments. This revised design solves > all the problematic issues related to exotic objects’ and DOM objects’ > subclassing, and will enable us, we hope, to ship a full and complete > implementation of ES6 classes quickly. > > After this positive change of course however, implementation of ES6 > classes in V8 is no longer conformant to, or a conservative subset of, this > new revised design. As a responsible standards implementation vendor, and > following the guidelines of our launch process [3], we made the decision to > unship our implementation of ES6 classes. > > > ES6 class syntax will not, for the time being, be available in V8 (and > therefore in Chromium) without flags. > > > ES6 classes will still be available under --harmony-classes flag in V8, > and under ‘Enable experimental Javascript features’ flag in Chromium. > > I would like to take this opportunity to thank all TC39 committee members, > and in particular, ECMAScript specification editor Allen Wirfs-Brock, for > springing into action so quickly, and working during over what for many of > them, I am sure, were winter holidays and time of their hard-earned > vacations to make sure ES6 classes specification is consistent, > implementable and addresses the language use cases in all their fullness, > while still staying on the tight schedule for completing ES6 standard. > > Dmitry, on behalf of V8 team. > > [1] https://groups.google.com/forum/#!topic/v8-users/bwEPA3vcscg > > [2] > https://github.com/tc39/ecma262/blob/master/workingdocs/ES6-super-construct%3Dproposal.md > > [3] https://developers.google.com/v8/launchprocess > > -- > -- > v8-users mailing list > [email protected] > http://groups.google.com/group/v8-users > --- > You received this message because you are subscribed to the Google Groups > "v8-users" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. > -- -- v8-users mailing list [email protected] http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups "v8-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
