JavaScript inherit

extends.js

/* simple */
var extends = function(child, parent) {
    var F = function() { }
    F.prototype = parent.prototype
    child.prototype = new F()
    child.prototype.constructor = child
    child.superclass = parent.prototype
}

/* from CoffeeScript */
var extends = function(child, parent) {
    for (var key in parent) { 
        if (Object.prototype.hasOwnProperty.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;
};