Traversal in insertion order for Set.prototype.add/delete

Mark S. Miller erights at
Thu Apr 24 07:36:11 PDT 2014

I don't understand the issue. Could you give a tiny example test case for
checking the specced order vs one for checking the order as you think it
should be specced?

On Wed, Apr 23, 2014 at 8:54 PM, Qantas 94 Heavy <qantas94heavy at>wrote:

> We need a deterministic order. What deterministic order do you suggest?
>> Why would it be better?
> Sorry for the confusion, I completely worded that wrong.
> I'm specifically referring to the specification sections
> and (specifying the behaviour for Set#add and Set#delete), which
> states that:
> 6. Repeat for each e that is an element of entries, *in original
>> insertion order*
> I don't see any real reason why that's needed, unless there's some odd
> side effects of doing so that I'm not aware of. Sets are meant to be unique
> and I don't think the order of checking whether the element already exists
> really matters. I'm not advocating for any change for the deterministic
> order of iteration in Set#forEach and for-of loops on sets.

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