Maybe monad implemented in javascript

maybe.js

function Maybe(value) {
  this.value = value;
}

Maybe.Nothing = {};

Maybe.pull = function (value) {
  return new Maybe(value);
}

Maybe.prototype.bind = function (fn) {
  if (this.value === Maybe.Nothing) {
    return Maybe.pull(Maybe.Nothing);
  } else {
    return fn(this.value);
  }
}

function fromMaybe(fail, maybe) {
  if (maybe.value === Maybe.Nothing) {
    return fail();
  } else {
    return maybe.value;
  }
}