Le 02/11/2013 01:08, Brandon Benvie a écrit :
> On 11/1/2013 4:59 PM, Brandon Benvie wrote:
>> On 11/1/2013 4:31 PM, Brandon Benvie wrote:
>>> In the spec for Object.prototype.toString:
>>>
>>> 'If tag is any of "Arguments", "Array", "Boolean", "Date", "Error", 
>>> "Function", "Number", "RegExp", or "String" and SameValue(tag, 
>>> builtinTag) is false, then let tag be the string value "~" 
>>> concatenated with the current value of tag.'
>>
>> An interesting consequence of this is that a Proxy for any of these 
>> will default to being "~" + target class. So 
>> `Object.prototype.toString.call(new Proxy([], {}))` is "[object 
>> ~Array]". But it seems the shipped has already sailed on Proxies 
>> being conspicuously not interchangeable with their targets in many 
>> cases...
>
> Actually that's incorrect. Proxies explicitly will return "Proxy" for 
> their tag. Same problem though.
In what other ways the ship has sailed?
At least regular objects and arrays can be faithfully interchanged I 
think, no? Things get complicated with Date/WeakMap/etc because of 
private state, but I remain hopeful a solution can be found in the ES7 
timeframe (or whatever the next iteration is called).

I'm not sure about proxy returning "Proxy" as tag name. Is that a good 
idea? Brand feels like something that could safely transparently cross 
proxies.

David

> Actually that's incorrect. Proxies explicitly will return "Proxy" for 
> their tag. Same problem though.

In what other ways the ship has sailed?
At least regular objects and arrays can be faithfully interchanged I 
think, no? Things get complicated with Date/WeakMap/etc because of 
private state, but I remain hopeful a solution can be found in the ES7 
timeframe (or whatever the next iteration is called).

I'm not sure about proxy returning "Proxy" as tag name. Is that a good 
idea? Brand feels like something that could safely transparently cross 
proxies.