On Jan 22, 2012, at 7:36 PM, Tab Atkins Jr. wrote:
> ...
> I have a question, that may be an objection. In my blog post
> <http://www.xanthir.com/blog/b4FJ0>, I demonstrate several example
> usages of Names. Most of them involve using a Name that's hung off of
> another object. Is there a way to support this pattern without a
> temporary variable?
I agree, this is another common use case that I should have mentioned in my
message.
An alternative to handing such private names off of object is to export them as
const bindings from a module. You can see an example of this style in
http://wiki.ecmascript.org/doku.php?id=strawman:object_model_reformation#a_string_keyed_map
>
> For example, from my post:
>
> myCoolObject.prototype[Iterator.getIterator] = function(){...}
>
> Using @ for access, would
> "[email protected] = function(){...}" work,
> or would that attempt to retrieve a property using "Iterator" as a
> Name, then retrieve the "getIterator" property of that?
>
> If the latter, this is rather inconvenient for what I expect will be
> common patterns.
>
[email protected]
parses as: ((myCoolObject.prototype).@Iterator).getIterator
which probably is not what you desire.
Taking just what is in my basic proposal, you would have to express this using
a local variable:
const getIterator = Iterator.getIterator;
myCoolObject.prototype.@getIterator = function() {...}
If @( ) is allowed for property keys in object literals you could say:
obj = {
@(Iterator.getIterator): function () {...}
}
or using concise method syntax just
obj = {
@(Iterator.getIterator) () {...}
}
however if we want to directly use Iterator.getIterator as the key in a member
expression we would need to enable use of @() as the property name in a member
expression:
myCoolObject.prototype.@(Iterator.getIterator) = function () {...}
I'm still ambivalent whether we actually need this. I think I like the module
export pattern slightly better and might prefer to encourage that.
Another possible extension would be to allow private declarations of the form:
private getIterator = Iterator.getIterator;
this really would mean exactly the same as an equivalent with const (perhaps
the initializer might be throw if it doesn't evaluate to a private name) but it
emphasizes the intended usage.
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