Why call yield like this in koa?

Question

Node.js

Decided to learn koa. I got acquainted with the documentation, decided to look at the examples. Found this here . I can't figure out why to write:

this.body = yield render('list', { posts: posts });

As I understand it, by calling yield, we simply call the next app.use(). That is, it is middleware. And in theory, nothing should be returned.

Answer 1

On the question, read https://learn.javascript.ru/generator
Well, in general, this is outdated, use koa 2 , it uses a more understandableasync