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[email protected] Spec https://people.mozilla.org/~jorendorff/es6-draft.html sections 9.2.13, 14.1.6, 14.1.21, (and others) Summary The plan is to implement parsing and baseline code generation for rest parameters in non-arrow functions. Work in progress patch[1] <https://codereview.chromium.org/816913003/> has been written already. Motivation Aside from the fact that rest parameters have been in the harmony draft and are already shipped in browsers, there are some key benefits as far as V8 is concerned, and some general developer syntax sugar perks. In particular, it can help avoid kBadValueContextForArgumentsValue bailouts when attempting to optimize a function which performs an operation such as `var params = [].slice.call(arguments, 1)`. Implementing a baseline implementation of rest parameters is a good start for other similar features which build on top of this, including optional parameters, and support for the spread operator (and destructuring assignment with rest elements). There is an entry in the feature dashboard[2] <https://www.chromestatus.com/features/5937087912083456> and an associated launchbug[3] <https://code.google.com/p/v8/issues/detail?id=2159> Compatibility Risk Firefox has shipped this feature, and it is available in the IE preview release. According to draft changelogs[4] <http://wiki.ecmascript.org/doku.php?id=harmony:older_es6_drafts>, this feature has been essentially unchanged since 2011 (rev 1). Ongoing technical constraints Code for supporting rest parameters is fairly minimal, and does not introduce much in the way of complexity. Will this feature be supported on all six Blink platforms (Windows, Mac, Linux, Chrome OS, Android, and Android WebView)? Yes. Requesting approval to ship? No. *[1] Patch *https://codereview.chromium.org/816913003/ *[2] Dashboard entry *https://www.chromestatus.com/features/5937087912083456 [3] OWP launch tracking bug https://code.google.com/p/v8/issues/detail?id=2159 *[4] Draft changelogs* http://wiki.ecmascript.org/doku.php?id=harmony:older_es6_drafts, http://wiki.ecmascript.org/doku.php?id=harmony:specification_drafts -- -- 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.
