thunkify&co code snippet

t.js

var thunkify = require('thunkify');
var co = require('co');

function myThunk(userName,callback){
    callback(null , 'hello'+' '+ userName);
}

var myR = thunkify(myThunk);
function* fn(){
  var a = yield myR('a');
  console.log(a);
  return 'over'
 }

var f = fn();
var out = f.next();
console.log(out)
out.value(function (err,str){console.log(str)})
var out2 = f.next()
console.log(out2);