Introducing The 80/20 Guide to ES2015 Generators

I must confess, I really don't like most tech books. Except for when I got a copy of Instant HTML Programmer's Reference for Christmas when I was 10, I've never read a tech book cover-to-cover. For my first book, Professional AngularJS, my co-author and I assumed people would use the book more as a reference than a way to go from zero to AngularJS master. With that in mind, we designed the book as "The 4 Hour Body for AngularJS." Each chapter (and often sections within the chapter) is designed to be independent of the others, so you can pick and choose which concepts matter to you.

However, I was never quite satisfied with the "pick and choose" design. The rationale for that decision was that first, from an early stage we were encouraged to fill a certain page count, and second, we set out with the broad goal of "teach everybody everything about AngularJS." These two goals were at odds with our assumption that this book wouldn't be a page turner, and the "pick and choose" design was the best way to reconcile the difference. However, I thought that there had to be a better way to write an ebook.

Introducing My New Ebook

My new ebook, The 80/20 Guide to ES2015 Generators, takes a different approach. In the spirit of the eponymous Pareto distribution, the ebook is all about taking you from novice to expert in the minimum amount of time, with laser focus on avoiding outside dependencies and other inconsequential details. This ebook is focused on generators as defined in the ES2015 spec, and does not attempt to teach you how to use babel, webpack, or anything else that is not absolutely necessary to use generators as defined in the spec. The ebook is designed to be read in 1-2 hours, and to provide you a solid understanding of generator fundamentals by teaching you:

• How to write your own co. Co and the notion of asynchronous coroutines enables you to write asynchronous code without callbacks or promise.then().

const co = require('co');
const superagent = require('superagent');

co(function*() {
  const html = (yield superagent.get('http://google.com')).text;
});

• How to build on co to write your own koa, AKA "Express' spiritual successor". In particular, you'll see how to implement your own koa-compose, the module that powers koa's generator-based middleware.

const koa = require('koa');
const superagent = require('superagent');
const app = koa();

app.use(function*(next) {
  try {
    yield next;
  } catch(error) {
    this.body = error.toString();
    this.status = 500;
  }
});

app.use(function*(next) {
  // The above try/catch will catch any HTTP errors
  this.body = (yield superagent.get('http://google.com')).text;
  yield next;
});

• How to build your own rudimentary transpiler based on regenerator

To be a JavaScript developer in 2016, you need to have a solid ES2015 foundation, and to have a solid ES2015 foundation, you need to master generators. Get the ebook and associated code samples at es2015generators.com and get a head start on the future of JavaScript.