Thank you for sharing the intent with blink-dev! Does it mean that you also intend to ship @@iterator methods (unclear from your post)?
How much of an effort is implementing the late specification addition? A complete implementation is preferred. Can the lack of it be feature detected quickly (throwing is not very nice to feature detect)? ☆*PhistucK* On Thu, Aug 7, 2014 at 12:16 PM, Andy Wingo <[email protected]> wrote: > For-of ("for (x of iterable) {}") is a part of ES6 [1]. > > For-of has been shipping in Firefox since version 27 (February 2014) > [2]. IE and Safari developers have both shown willingness to implement > this part of the new language standard. > > V8 has had for-of since June 2013, under the --harmony-iteration flag. > It was recently changed to perform GetIterator [3] on the iterable, in > conformance with the draft standard. > > At the same time, we are looking to ship standard @@iterator methods for > arrays [4] and strings [5], so that one can iterate over arrays and > strings natively: > > for (var x of [1,2,3]) console.log(x); > > These @@iterator implementations make use of the new ES6 symbol facility > (also shipping in M38). > > V8's for-of implementation is complete with respect to the current draft > standard, except for the late spec addition that causes for-of to "shut > down" the iterator on early exit (via break or throw) [6]. We don't > anticipate problems adding this functionality later, as it relies on the > iterator having an optional "close" method, which no iterators have > currently. > > Owners: [email protected], [email protected] > > [1] > http://people.mozilla.org/~jorendorff/es6-draft.html#sec-for-in-and-for-of-statements > [2] https://developer.mozilla.org/en-US/Firefox/Releases/27#JavaScript > [3] http://people.mozilla.org/~jorendorff/es6-draft.html#sec-getiterator > [4] > http://people.mozilla.org/~jorendorff/es6-draft.html#sec-string-iterator-objects > [5] > http://people.mozilla.org/~jorendorff/es6-draft.html#sec-array-iterator-objects > [6] http://esdiscuss.org/notes/2014-06-05#closing-iterators > > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > -- -- 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.
