Over the past couple of months, we have implemented support for BigInts in V8, as currently specified by this proposal, to be included in a future version of ECMAScript. The following post tells the story of our adventures.
Proxies have been an integral part of JavaScript since ES2015. They allow intercepting fundamental operations on objects and customizing their behavior. Proxies form a core part of projects like jsdom and the Comlink RPC library. Recently, we put a lot of effort into improving the performance of proxies in V8. This article sheds some light on general performance improvement patterns in V8 and for proxies in particular.
The V8 team places great importance on the evolution of JavaScript into an increasingly expressive and well-defined language that makes writing fast, safe, and correct web applications easy. In June 2015, the ES2015 specification was ratified by the TC39 standards committee, making it the largest single update to the JavaScript language. New features include classes, arrow functions, promises, iterators / generators, proxies, well-known symbols, and additional syntactic sugar. TC39 has also increased the cadence of new specifications and released the candidate draft for ES2016 in February 2016, to be ratified this summer. While not as expansive as the ES2015 update due to the shorter release cycle, ES2016 notably introduces the exponentiation operator and Array.prototype.includes.
Introduced with the third edition of the ECMA-262 specification, regular expressions have been part of Javascript since 1999. In functionality and expressiveness, JavaScript’s implementation of regular expressions roughly mirrors that of other programming languages.
Math.random()returns aNumbervalue with positive sign, greater than or equal to0but less than1, chosen randomly or pseudo-randomly with approximately uniform distribution over that range, using an implementation-dependent algorithm or strategy. This function takes no arguments.