coroutine.js

#!env NODE_PATH=/usr/local/lib/node_modules node --harmony

var Promise = require("bluebird")

var b = Promise.method(function() {
  throw new Error("omg");
  return "b";
})

var a = Promise.coroutine(function *() {
  var ret = yield b();
  return ret;
});

a().then(function(v) {
  console.log("Value", v);
}).catch(function(e) {
  console.log("Error", e);
});