features in Firefox?

Andreas Rossberg rossberg at
Mon Jan 2 02:37:40 PST 2012

On 25 December 2011 13:26, Axel Rauschmayer <axel at> wrote:
> Paul Irish did a code search for that:

To elaborate, the --harmony flag currently activates the following
experimental features for V8:

- block scoping, let, const, block functions
- proxies, though not direct proxies yet (i.e.,
- maps and sets
- weak maps (
- typeof null reform

On the browser side, that should become functional in Chrome 17 (some
of it is in 16 already, but incomplete/buggy) by setting
--js-flags="--harmony". If you are on the Chrome dev channel, you
should also see it show up on chrome://flags soon.


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