Tag Archives: V8

Node.js ES6 Support

Come on TC39, V8 and Node have implemented all but the most obscure parts of ES6–where is the standard for import?


NodeJS 6.1 passes 96% of ES6 tests, failing only on proper tail calls, iterator closing, and some Proxying of internal `get` calls.

But no standard is in sight for resolving resources based on the string in import statements.

View the compatibility table results at node.green

V8 JavaScript Engine: V8 Release 4.9

Chrome 49 boasts 91% ES6 support


In V8 release 4.9 we shipped more JavaScript ES2015 features than in any other previous release, bringing us to 91% completion as measured by the Kangax compatibility table (as of January 26). V8 now supports destructuring, default parameters, Proxy objects, and the Reflect API.

Release 4.9 also makes block level constructs such as class and let available outside of strict mode and adds support for the sticky flag on regular expressions and customizable Object.prototype.toString output.

Read more from the source: v8project.blogspot.com

Boosting JavaScript Performance – A Google Experiment

Google’s proposes “use strong”; a subset of JavaScript that will allow V8 to enjoy some significant speed boosts


Like the restrictions in Strict Mode, Strong Mode aims to boost JavaScript performance. Some of the dynamic aspects of JavaScript hold back VM speed. Instead of “use strict”; it would be “use strong”; Strong Mode is actually a subset of Strict Mode.

The changes are still in the proposal stage but could have a bright future.

Restrictions in Strong Mode include accessing missing properties throw exceptions, arrays cannot be sparse, all scoping errors are static, and classes are immutable.

Read more from The Google Developers Blog