Saturday, June 4, 2016

V8 Release 5.2

Roughly every six weeks, we create a new branch of V8 as part of our release process. Each version is branched from V8’s git master immediately before Chrome branches for a Chrome Beta milestone. Today we’re pleased to announce our newest branch, V8 version 5.2, which will be in beta until it is released in coordination with Chrome 52 Stable. V8 5.2 is filled will all sorts of developer-facing goodies, so we’d like to give you a preview of some of the highlights in anticipation of the release in several weeks.

ES6 & ES7 support

V8 5.2 contains support for ECMAScript 6 (aka ES2015) and ECMAScript 7 (aka ES2016).

Exponentiation operator

This release contains support for the ES7 exponentiation operator, an infix notation to replace Math.pow.
let n = 3**3; // n == 27
n **= 2; // n == 729

Evolving spec

For more information on the complexities behind support for evolving specifications and continued standards discussion around web compatibility bugs and tail calls, see the V8 blog post ES6, ES7, and beyond.

Performance

V8 5.2 contains further optimizations to improve the performance of JavaScript built-ins, including improvements for Array operations like the isArray method, the in operator, and Function.prototype.bind. This is part of ongoing work to speed up built-ins based on new analysis of runtime call statistics on popular web pages. For more information, see the V8 Google I/O 2016 talk and look for an upcoming blog post on performance optimizations gleaned from real-world websites.

V8 API

Please check out our summary of API changes. This document gets regularly updated a few weeks after each major release.

Developers with an active V8 checkout can use 'git checkout -b 5.2 -t branch-heads/5.2' to experiment with the new features in V8 5.2. Alternatively you can subscribe to Chrome's Beta channel and try the new features out yourself soon.

Posted by the V8 team

4 comments:

  1. So much great work coming from you guys these days!

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  2. Wow, a "feature" that is a shorthand for Math.pow. What progress you are making towards the engine, not!

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    1. Nick, if you have an issue with this, participate in the discussion of the proposal (https://github.com/rwaldron/exponentiation-operator). I for one am very grateful that the V8 team is following the evolving ECMAScript specification(s). Your comment is counterproductive and misguided.

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