Web IDL Garden Hose

Maciej Stachowiak mjs at apple.com
Sun Sep 27 16:04:31 PDT 2009


On Sep 27, 2009, at 11:14 AM, Brendan Eich wrote:

> On Sep 27, 2009, at 10:41 AM, David-Sarah Hopwood wrote:
>
>> Brendan Eich wrote:
>>> On Sep 26, 2009, at 6:08 PM, Maciej Stachowiak wrote:
>>>
>>>> This may provide a way to implement some of these behaviors in pure
>>>> ECMAScript. The current proposal does allow [[Construct]] without
>>>> [[Call]], but not [[Call]] and [[Construct]] that both exist but  
>>>> with
>>>> different behavior.
>>>
>>> Date needs the latter.
>>
>> That can already be done in ES5. As I've previously suggested:
>>
>> function Date(yearOrValue, month, date, hours, minutes, seconds,  
>> ms) {
>>   "use strict";
>>   if (this === undefined) {
>>     return TimeToString(CurrentTime());
>>   }
>>   // constructor behaviour
>>   ...
>> }
>
> Of course, a variation on "the idiom".
>
> This is similar to what many implementations do too, rather than the  
> implementation providing analogues of [[Call]] and [[Construct]]  
> internal method on a non-function Date object. It works for Boolean,  
> Number, String, and RegExp too.
>
> But it is just a bit unsightly!

Will this do the right thing if you explicitly bind Date to a "this"  
value, for example, by calling it as window.Date(), or using call,  
apply, or function.bind, or by storing Date as the property of another  
random object?

Regards,
Maciej



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