On Feb 3, 2014, at 8:51 PM, Vic99999 wrote:

>> There was a SpiderMonkey bug1, and even a patch, for this for quite a while. The patch now landed and will be in Firefox 29.
> 
>> V8 got fixed last week too
>> code.google.com/p/v8/issues/detail?id=3069
> 
> but according to spec, "forEach" should call callback with "-0":
> 

Good catch!  This allow applies to 'keys' and 'entries' enumeration.

I seems to me, that if we want -0 and 0 to act as the same key value, that we need to normalize -0 to 0 when storing it as a map key.  SameValue0 remains what we want to use when doing a key lookup,

Allen

On Feb 3, 2014, at 8:51 PM, Vic99999 wrote:

> but according to spec, "forEach" should call callback with "-0":

Good catch!  This allow applies to 'keys' and 'entries' enumeration.

I seems to me, that if we want -0 and 0 to act as the same key value, that we need to normalize -0 to 0 when storing it as a map key.  SameValue0 remains what we want to use when doing a key lookup,