Are frozen Objects faster ?

Mark S. Miller erights at
Thu Feb 14 10:08:15 PST 2013

On Thu, Feb 14, 2013 at 10:01 AM, Kevin Gadd <kevin.gadd at> wrote:

> Frozen and sealed objects are both dramatically slower in most JS
> engines I've tested. In the ones where they're not dramatically slower
> they are never faster.
> The last time I asked on the mozilla and v8 bug trackers I was
> informed that there is no plan to optimize for these features and that
> the design of the respective JS engines would make such optimizations
> difficult anyway.
> (I find this extremely unfortunate.)

Likewise. And unlikely.

Based on history, I suggest that the best way to get this situation fixed
is benchmarks. Either create a new benchmark or a variation of an existing
benchmark. For example, if someone created a variant of SunSpider in which
all objects that don't need to not be frozen were frozen, and posted the
measurements, that would help get everyone's attention. The situation might
then improve rapidly.

> -kg
> On Thu, Feb 14, 2013 at 9:48 AM, Andrea Giammarchi
> <andrea.giammarchi at> wrote:
> > If not, any particular reason these are not, being immutable and
> > representable similar to a C struct ?
> >
> > If they could, any idea which engine is planning to optimize and when?
> >
> > Thanks and Best Regards
> _______________________________________________
> es-discuss mailing list
> es-discuss at

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