@babel/plugin-transform-async-generator-functions

async-generator-functions - 图1info

This plugin is included in @babel/preset-env, in ES2018

Example

In

JavaScript

  1. async function* agf() {
  2.   await 1;
  3.   yield 2;
  4. }

Out

JavaScript

  1. var _asyncGenerator = ...
  3. let agf = (() => {
  4.   var _ref = _asyncGenerator.wrap(function* () {
  5.     yield _asyncGenerator.await(1);
  6.     yield 2;
  7.   });
  9.   return function agf() {
  10.     return _ref.apply(this, arguments);
  11.   };
  12. })();

For await example

JavaScript

  1. async function f() {
  2.   for await (let x of y) {
  3.     g(x);
  4.   }
  5. }

Example Usage

JavaScript

  1. async function* genAnswers() {
  2.   var stream = [Promise.resolve(4), Promise.resolve(9), Promise.resolve(12)];
  3.   var total = 0;
  4.   for await (let val of stream) {
  5.     total += await val;
  6.     yield total;
  7.   }
  8. }
  10. function forEach(ai, fn) {
  11.   return ai.next().then(function(r) {
  12.     if (!r.done) {
  13.       fn(r);
  14.       return forEach(ai, fn);
  15.     }
  16.   });
  17. }
  19. var output = 0;
  20. forEach(genAnswers(), function(val) {
  21.   output += val.value;
  22. }).then(function() {
  23.   console.log(output); // 42
  24. });

Try it Out in the REPL

Installation

  • npm
  • Yarn
  • pnpm
  1. npm install --save-dev @babel/plugin-transform-async-generator-functions
  1. yarn add --dev @babel/plugin-transform-async-generator-functions
  1. pnpm add --save-dev @babel/plugin-transform-async-generator-functions

Usage

With a configuration file (Recommended)

babel.config.json

  1. {
  2.   "plugins": ["@babel/plugin-transform-async-generator-functions"]
  3. }

Via CLI

Shell

  1. babel --plugins @babel/plugin-transform-async-generator-functions script.js

Via Node API

JavaScript

  1. require("@babel/core").transformSync("code", {
  2.   plugins: ["@babel/plugin-transform-async-generator-functions"],
  3. });

References