- From: Boris Zbarsky <bzbarsky@MIT.EDU>
- Date: Mon, 19 Nov 2012 08:38:49 -0500
- To: whatwg@lists.whatwg.org
On 11/19/12 2:36 AM, David Bruant wrote:
> An ES6 proxy could do the trick here.
But then it's not a Map at all, right? It's a proxy for maybe a Map,
maybe something else. In what sense would it be a Map at that point?
>> I suppose the same goes for ES6 Map.
> As Tab suggested, a Map subclass could certainly work
How close are "subclasses" to not being vaporware (both in spec and
implementation terms)? Speccing things in terms of vaporware makes them
pretty hard to implement in actual implementations... Doesn't mean we
shouldn't do it, but I'm a bit wary of it, in general.
> The ordered part for objects wasn't true in ES5 (implementation specific
> order), but is considered for ES6 [1] since all web engines do the same
> order
Except they don't. Here's a trivial example:
var obj = {};
obj["2"] = 5;
obj["1"] = 0;
which is handled differently by different UAs. The "same order" bit is
only true for property names that don't look like array indices. Per
proposed spec you linked to, by the way, this will enumerate properties
in the order "1" followed by "2".
Of course nothing really stops pages from using url parameters whose
names look like array indices. So if we want ordered here, we just
can't use a object to do it.
-Boris
Received on Monday, 19 November 2012 15:41:51 UTC