foo.js

var Foo, f,
 bind = function(fn, me){ return function(){ return fn.apply(me, arguments); }; },
 extend = function(child, parent) { for (var key in parent) { if (hasProp.call(parent, key)) child[key] = parent[key]; } function ctor() { this.constructor = child; } ctor.prototype = parent.prototype; child.prototype = new ctor(); child.__super__ = parent.prototype; return child; },
 hasProp = {}.hasOwnProperty;
 
Foo = (function(superClass) {
 extend(Foo, superClass);
 
 function Foo() {
   this.sayHello = bind(this.sayHello, this);
   return Foo.__super__.constructor.apply(this, arguments);
 }
 
 Foo.prototype.sayHello = function(name) {
   return console.log("Hello, " + name + "!");
 };
 
 return Foo;
 
})(Bar);
 
f = new Foo();
 
setImmediate(function() {
 return f.sayHello("Dave");
});