Original URL: http://www.theregister.co.uk/2014/01/17/dart_1_1_matches_javascript/

Dart 1.1 bullseyes JavaScript performance in latest benchmarks

Compiled apps now match or beat handwritten JavaScript

By Neil McAllister

Posted in Developer, 17th January 2014 23:29 GMT

Just two months after shipping the first production-ready version of Dart, its JavaScript competitor, Google has offered up a new version that it claims can output code that runs as fast or faster than the equivalent routines written in JavaScript.

Dart has always been fast when running in a native VM. In fact, Dart benchmarks running in Dart VM have consistently outperformed the equivalent JavaScript running in Google's own V8 JavaScript engine. But almost nobody runs client-side Dart applications this way in the real world, because no mainstream browser currently ships with Dart VM. Instead, production Dart web apps are typically "compiled" into JavaScript using dart2js, the Dart SDK's code translator.

That hasn't always worked out so well. Past versions of dart2js have generally produced code that runs slower than it would if the same routines had been hand-written in JavaScript. But according to a blog post by Google developer advocate Seth Ladd, Dart 1.1, which Google released on Thursday, has all but closed that gap.

"Dart2js now generates JavaScript that performs as well as, if not better than, the idiomatic JavaScript equivalent," Ladd wrote.

When compiled to JavaScript, Dart 1.1's performance on the Richards benchmark – a torture test designed to compare the efficiency of systems programming languages – is up 25 per cent when compared to Dart 1.0. Its performance on the more recent FluidMotion benchmark has doubled. You can see the full results of Google's benchmark tests on the Dart project's performance page, here.

Improving client-side performance wasn't the only focus of the new release, either. Ladd said there is growing interest in using Dart for server-side applications – presumably, because it's easy to run Dart VM on a server, among other reasons – and Dart 1.1 includes a number of new features designed to accommodate this.

The new release now supports large files, file copying, process signal handlers, accessing output terminal information, and the UDP networking protocol – the latter of which should make it easier to write streaming media applications in Dart.

In addition, Dart's HTTP stack has been optimized since the last release, latency has been decreased for many I/O operations, and performance of asynchronous operations has been improved.

Dart 1.1 also bundles a souped-up Dart Editor that improves debugging and code completion and offers more descriptive tooltips, in addition to various performance enhancements.

Google has updated the Dart language spec to coincide with this release and it has also published new developer how-tos on writing command-line applications, Dart-JavaScript interoperability, and using data streams.

If you're the type who prefers to just dive right in, however, you can download all of the updated tools, including dart2js and the improved Dart Editor, from the Dart homepage, here. ®