ECMAScript 2015, also referred to as ECMAScript 6, has been approved by ECMA International, the organization said this week. The move provides stability to the technology.
The upgrade to the specification underlying JavaScript has been praised for syntax improvements and improving structural issues, and features of it already have been implemented in browsers. "Approval means the most significant update to ECMAScript since 1999 is now completed and has become an international standard," said Alan Wirfs-Brock, project editor for the specification and a Mozilla research fellow, in an email. "Browser developers can now complete their implementations of ECMAScript 2015 features knowing that the specification is final and no longer subject to change."
Wirfs-Brock said the primary goals for ECMAScript 2015 are better support for large applications, library creation, and the use of ECMAScript as a compilation target for other languages. Major enhancements include modules, class declarations, lexical block scoping, iterators and generators, promises for asynchronous programming, destructuring patterns, and proper tail calls. Also, the ECMAScript library of built-ins has been expanded to support additional data abstractions, including maps, sets, and arrays of binary numeric values as well as additional support for Unicode supplemental characters in strings and regular expressions. The built-ins are now extensible via sub=classing.
Developers should now see much more frequent updates to the specification. "[ECMA Technical Committee 39's] intent is that ECMAScript 2015 is the new foundation for the future of ECMAScript," Wirfs-Brock said. "Rather than waiting five to 15 years for another major revision, TC39 intends to better respond to the needs of Web developers by making annual incremental enhancements to the ECMAScript specification." Work is already underway on ECMAScript 7.
Another Mozilla official, David Bryant, vice president of Platform Engineering and Interim CTO, noted via email that Mozilla has participated in the specification's development. "Every once in a while, a piece of technology is situated in the right place at the right time, and it ends up underpinning the success of the Web. JavaScript was one such piece of technology. The approval of ECMAScript 6 marks a new foundation for what may be the most important programming language of the next several decades"