17648 2012-06-29 08:32:11 +0000 [Awaiting ES6] Add iterators 2014-10-05 17:11:46 +0000 1 1 1 Unclassified WebAppsWG WebIDL unspecified PC Windows 3.1 RESOLVED FIXED P2 normal --- 23210 23211 23212 26102 26183 1 annevk cam allen bzbarsky cam d erights erik.arvidsson mike Ms2ger public-script-coord www-dom public-webapps-bugzilla oldest_to_newest 69530 0 annevk 2012-06-29 08:32:11 +0000 http://lists.w3.org/Archives/Public/public-script-coord/2012AprJun/thread.html#msg239 heycam suggests at least NodeList/HTMLCollection need this, but if they can have [ArrayClass] that would be better. https://bugs.webkit.org/show_bug.cgi?id=81573 suggests [ArrayClass] is probably not going to happen, but who knows, it is not resolved wontfix just yet. 69531 1 Ms2ger 2012-06-29 09:01:03 +0000 I think this should be done in WebIDL for all interfaces that support indexed properties, fwiw. 80090 2 annevk 2012-12-13 10:55:30 +0000 heycam, what do you think? 80160 3 cam 2012-12-14 05:31:35 +0000 Iterators have already been added to the spec, so if people want to write explicit ones for their interfaces they can. http://dev.w3.org/2006/webapi/WebIDL/#idl-iterators http://dev.w3.org/2006/webapi/WebIDL/#es-iterators But I like the idea of having iterators by default for objects that support indexed properties. This could be overridden if you explicitly declare an iterator. 80161 4 cam 2012-12-14 05:57:10 +0000 The ES6 draft has changed a lot since I looked at it last. :) I can't see mention of iterator() methods on objects any more, which is what Web IDL is written against at the moment. Maybe that strawman changed before being added to the spec. I can see in section 12.6.4 (dealing with for-in and for-of loops), the runtime semantics of the "For In/Of Expression Evaluation" abstract operation, step 7.b says: Let keys be the result of performing Invoke with arguments obj, %iterator%, and an empty List. but there doesn't seem to be a definition for this intrinsic object %iterator%. Maybe that's meant to be an intrinsic symbol @@iterator? Anyway, it feels like the spec isn't quite done on this yet, so perhaps I should wait a bit. 99203 5 cam 2014-01-27 21:45:20 +0000 Thread at http://www.w3.org/mid/520FE9BF.5060902@gmail.com mentioned this bug too. 100428 6 annevk 2014-02-12 19:46:45 +0000 Given that we could theoretically snapshot live lists, I asked arv, he said "I think we should keep them live. ArrayIterator is live. Doing `NodeList.prototype[Symbol.iterator] = Array.prototype[Symbol.iterator]` works fine with live lists." 100439 7 bzbarsky 2014-02-12 21:13:00 +0000 Fwiw, that's basically what Gecko implements right now. We've had a few complaints about it, in the usual way. Live lists suck to work with. :( 112350 8 cam 2014-09-29 04:12:28 +0000 I've updated the spec to use @@iterator and reference other abstract iterator-related operations from the ES6 spec. I've removed interface interfaces, as they were a complication that I'm not sure we need. I've also updated the iterator that exists automatically due to declaring indexed properties to just use the default Array iterator. An easier way to iterate over a set of objects -- bug 26183 -- is still to come. https://github.com/heycam/webidl/commit/f87ea39994972ebd75f4b98c2dc01a32aaa9d1f5 112351 9 cam 2014-09-29 04:28:43 +0000 (In reply to Cameron McCormack from comment #8) > An easier way to iterate over a set of objects -- bug 26183 -- is still to > come. "list of values", not "set of objects". 112680 10 bzbarsky 2014-10-04 04:38:48 +0000 Do we actually want to make the @@iterator property enumerable? It doesn't affect for..in enumeration either way, since that skips symbol-named props, but it seems like we might want to not make it enumerable in general. 112681 11 cam 2014-10-04 05:01:16 +0000 Oh, I think we should be using the defaults mentioned in https://people.mozilla.org/~jorendorff/es6-draft.html#sec-ecmascript-standard-built-in-objects, i.e. { [[Writable]]: true, [[Enumerable]]: false, [[Configurable]]: true }. 112682 12 cam 2014-10-04 05:10:00 +0000 Fixed that: https://github.com/heycam/webidl/commit/650316df6cdd154fd759a9d5b5130a67ce142aa1 I wasn't sure what to do about @@toStringTag, as some properties with this name in the ES6 spec are configurable and some are not. Just added an ednote for now. 112721 13 allen 2014-10-05 17:11:46 +0000 (In reply to Cameron McCormack from comment #12) > I wasn't sure what to do about @@toStringTag, as some properties with this > name in the ES6 spec are configurable and some are not. Just added an > ednote for now. That's a bug in the ES6 spec (now fixed in my draft) All standard @@toStringTag properties should be non-writable (unless an accessor), non-enumerable, and configurable