Yield

Lightning talk.
How Generators and Co can make asynchronous code look better.
Where to use it - from Co to Koa.

Transcript

1. yield @krzychukula
2. function(){ getUsername(function(err, username){ getUser(username, function(err, user){ //use username and user }) }) }
3. function(){ getUsername() .then(function (username) { return [username, getUser(username)]; }) .spread(function (username, user) { //use username and user }); }
4. co(function *(){ var username = yield getUsername() var user = yield getUser(username) //use username and user })
6. Generators
7. Co
9. co(function *(){ var username = yield getUsername() var user = yield getUser(username) //use username and user })
10. co(function *(){ var username = “janek” var user = yield getUser(username) //use username and user })
11. co(function *(){ var username = “janek” var user = {id:”123”} //use username and user })
12. Koa
13. var koa = require('koa'); var app = koa(); app.use(function *(){ this.body = 'Hello World'; }); app.listen(3000);
14. function *list() { var res = yield books.find({}); this.body = res; }
15. nvm install v4
16. Play with it!
17. Thanks! krzychukula.blogspot.com