IIRC, the module `core-decorators` (a module of utility decorators) have
both of those. That seems ideal, since it's not something that would
massively benefit from being within the standard library itself.
On Tue, Aug 8, 2017, 02:32 Naveen Chawla <naveen.c...@gmail.com> wrote:
> Ah great! So then how about having a `@seal` and/or `@preventExtensions`
> decorator as a shorthand?
>
> I accept that IDEs can only do so much in checking your code, and beyond
> that, you're on your own...
>
> Secretly I want Javascript to become like TypeScript... all optional,
> backwards compatible, etc.
>
> On Tue, 8 Aug 2017 at 11:16 Darien Valentine <valentin...@gmail.com>
> wrote:
>
>> For a class which is not intended to be subclassable, this can be done
>> today
>> with `Object.preventExtensions()` or `Object.seal()`, depending on your
>> intent:
>>
>> class Foo {
>> constructor() {
>> this.bar = 1;
>> this.baz = 2;
>>
>> Object.preventExtensions(this);
>> }
>> }
>>
>> const foo = new Foo();
>>
>> foo.bar = 3; // okay
>> foo.qux = 4; // throws in strict mode
>>
>> But this approach doesn’t work when subclassing is or may be in play.
>> It’s also not
>> directly possible with the decorator proposal as it stands today — but
>> there has
>> been discussion of it and it sounds like it’s something that’s on
>> people’s minds:
>>
>> [2017 July 27](
>> http://tc39.github.io/tc39-notes/2017-07_jul-27.html#11ive-interaction-of-privacy-fields-and-decorators
>> )
>>
>> > DE: Omitted features: instance finishers. Yehuda?
>> >
>> > YK: an instance finisher is a function that is executed at the end of
>> > instantiation of the class at any subclass level and passes at the
>> > instance. this is at the end of Reflect.construct. the use case is a
>> > decorator to confirm that all instances are frozen or sealed. Another:
>> > you want to register created instance into a map. The subclass provides
>> > the key, the superclass expresses that the instance should be
>> registered.
>> >
>> > DE: instance finishers change how instances are created. It's
>> > complicated and so wants to separate it out.
>>
>> ...looking forward to this, too.
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>> https://mail.mozilla.org/listinfo/es-discuss
>>
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