WeakSet can be very useful in general to avoid *any* object to be visited/setup twice, not just those coming from user-land classes.
Circular references, mixins, DOM nodes one-off events handling, and so on and so fort. On Mon, Apr 22, 2019 at 8:26 PM #!/JoePea <[email protected]> wrote: > (I edited the broken format of my previous post) > > What other use cases are there? > > On Mon, Apr 22, 2019 at 11:20 AM #!/JoePea <[email protected]> wrote: > >> > WeakSets are perfect for branding and are how I would expect web >> platform class branding to be explained. >> > >> > ```js >> > const foos = new WeakSet(); >> > >> > class Foo { >> > constructor() { >> > foos.add(this); >> > } >> > >> > method() { >> > if (!foos.has(this)) { >> > throw new TypeError("Foo.prototype.method called on an >> incompatible object!"); >> > } >> > } >> > } >> > ``` >> >> Just curious, is that effectively the same as what the (current) [private >> fields proposal](https://github.com/tc39/proposal-class-fields) offers? >> >> ```js >> class Foo { >> #isFoo = true >> >> method() { >> if (this.#isFoo) { >> throw new TypeError("Foo.prototype.method called on an incompatible >> object!"); >> } >> } >> } >> ``` >> >> - Joe >> > _______________________________________________ > es-discuss mailing list > [email protected] > https://mail.mozilla.org/listinfo/es-discuss >
_______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
