ES6 Generators

B.js

sync(function* (resume) {
  try (e) {
    yield setTimeout(resume, 1000);
    var greeting = yield _get('/something.ajax?greeting', resume)
    var who = yield _get('/else.ajax?who&greeting=' + greeting, resume)
    console.log(greeting + ' ' + who)
  }
  catch (e) {
    console.log(e);
    throw e;  
  } 
});