laser

function createAccount(email, password, done) {
  var id = uuid();

  async.waterfall([
    _.partial(Services.Accounts.provision, email, password),
    _.partial(Services.Notification.confirm, email)
  ],
  _.partial(done, _, id, _));
}

laser

function createAccount(email, password, done) {
  var id = uuid();

  async.waterfall([
    function(callback) {
      Services.Accounts.provision(email, password, callback);
    }, 
    function(accountId, callback) {
      Services.Account.enable(email, accountId, callback);
    }

laser

function partial(fx) {
  var firstArgs = Array.prototype.slice.call(arguments, 1);

  return function fx2() {
    var secondArgs = Array.prototype.slice.call(arguments, 0);
    return fx.apply(null, firstArgs.concat(secondArgs));
  };
}

laser

sumWithXFixedToTen(20); // 30
sumWithXFixedToTen(99); // 109

laser

var sumWithXFixedToTen = _.partial(sum, 10);

(typeof sumWithXFixedToTen); // Function

laser

[1, 2, 3, 4, 5].map(_.partial(sum, 10)); // [11, 12, 13, 14, 15]

laser

[1, 2, 3, 4, 5].map(function(n) {
  return sum(10, n);
}); // [11, 12, 13, 14, 15]

laser

[1, 2, 3, 4, 5].map(function(n) {
  return sum(10, n);
}); // [11, 12, 13, 14, 15]

laser

function sum(x, y) {
  return x + y;
}

laser

return fruitsOfTheWorld.map(function(fruits) {
  return fruits.map(capitalize);
});