What is `this` inside a new-invoked generator?
Question: what does the following code snippet log in the last line?
```js
function* gen() {
yield this;
}
let genObj = new gen();
let [_this] = genObj;
console.log(_this === genObj); // ???
```
I’m finding three answers:
1. The spec says [1] that any reference to `this` in a generator invoked via
`new` causes a `ReferenceError`.
2. Firefox logs `false` for the code snippet.
3. A year ago, Allen stated [2] that if you invoke a generator function via
`new`, `this` points to the generator object. On other words, the code snippet
would log `true`.
[1]
https://people.mozilla.org/~jorendorff/es6-draft.html#sec-generator-function-definitions-runtime-semantics-evaluatebody
[2]
https://esdiscuss.org/topic/reason-why-generators-do-not-have-references-to-themselves#content-8
--
Dr. Axel Rauschmayer
a...@rauschma.de
rauschma.de
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Re: What is `this` inside a new-invoked generator?
Question: what does the following code snippet log in the last line?
```js
function* gen() {
yield this;
}
let genObj = new gen();
let [_this] = genObj;
console.log(_this === genObj); // ???
```
I’m finding three answers:
1. The spec says [1] that any reference to `this` in a generator invoked via
`new` causes a `ReferenceError`.
2. Firefox logs `false` for the code snippet.
3. A year ago, Allen stated [2] that if you invoke a generator function via
`new`, `this` points to the generator object. On other words, the code snippet
would log `true`.
It's a ReferenceError. Future editions may add a meta property to make it possible to retrieve the
current generator object (https://bugs.ecmascript.org/show_bug.cgi?id=3626).
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