serialize some async functions in node 5

serializedemo6.js

// how we create the specialized callbacks
function createCallback(index) {
  return function (err, result) {
    var next = steps[index+1];
    var cb   = callbacks[index+1];
    if (err) {
      console.log('Error: ' + err.message);
    } else if (result) {
      console.log('Result: ' + JSON.stringify(result));
    }
    if (next) {
      next(cb);
    } else {
      console.log('Finished!');
      process.exit(0);
    }
  };
}