babel-plugin-transform-async-generator-functions

> Turn async generator functions and for-await statements to ES2015 generators

Example

In

``javascript
async function* agf() {
await 1;
yield 2;
}
`

Out

`javascript
var _asyncGenerator = ...

let agf = (() => {
var _ref = _asyncGenerator.wrap(function* () {
yield _asyncGenerator.await(1);
yield 2;
});

return function agf() {
return _ref.apply(this, arguments);
};
})();
`

For await example

`js
async function f() {
for await (let x of y) {
g(x);
}
}
`

Example Usage

`js
async function* genAnswers() {
var stream = [ Promise.resolve(4), Promise.resolve(9), Promise.resolve(12) ];
var total = 0;
for await (let val of stream) {
total += await val;
yield total;
}
}

function forEach(ai, fn) {
return ai.next().then(function (r) {
if (!r.done) {
fn(r);
return forEach(ai, fn);
}
});
}

var output = 0;
forEach(genAnswers(), function(val) { output += val.value })
.then(function () {
console.log(output); // 42
});
`

Try it Out in the REPL%20%7B%0A%20%20var%20stream%20%3D%20%5B%20Promise.resolve(4)%2C%20Promise.resolve(9)%2C%20Promise.resolve(12)%20%5D%3B%0A%20%20var%20total%20%3D%200%3B%0A%20%20for%20await%20(let%20val%20of%20stream)%20%7B%0A%20%20%20%20total%20%2B%3D%20await%20val%3B%0A%20%20%20%20yield%20total%3B%0A%20%20%7D%0A%7D%0A%0Afunction%20forEach(ai%2C%20fn)%20%7B%0A%20%20return%20ai.next().then(function%20(r)%20%7B%0A%20%20%20%20if%20(!r.done)%20%7B%0A%20%20%20%20%20%20fn(r)%3B%0A%20%20%20%20%20%20return%20forEach(ai%2C%20fn)%3B%0A%20%20%20%20%7D%0A%20%20%7D)%3B%0A%7D%0A%0Avar%20output%20%3D%200%3B%0AforEach(genAnswers()%2C%20function(val)%20%7B%20output%20%2B%3D%20val.value%20%7D)%0A.then(function%20()%20%7B%0A%20%20console.log(output)%3B%20%2F%2F%2042%0A%7D)%3B&experimental=true&loose=false&spec=false&playground=true&stage=0)

Installation

`sh
npm install --save-dev babel-plugin-transform-async-generator-functions
`

Usage

$3

.babelrc

`json
{
"plugins": ["transform-async-generator-functions"]
}
`

$3

`sh
babel --plugins transform-async-generator-functions script.js
`

$3

`javascript
require("babel-core").transform("code", {
plugins: ["transform-async-generator-functions"]
});
``

References

* Proposal: Asynchronous iteration for ECMAScript