Hash is a neat class for interable objects

hash.js

// A Hash is an interable object
var Hash = module.exports = Object.create(Object.prototype, {
  // Make for easy converting objects to hashes.
  new: {value: function initialize(value) {
    value.__proto__ = Hash;
    return value;
  }},
  // Implements a forEach much like the one for Array.prototype.forEach.
  forEach: {value: function forEach(callback, thisObject) {
    var keys = Object.keys(this),
        length = keys.length;
    for (var i = 0; i < length; i++) {
      var key = keys[i];
      callback.call(thisObject, this[key], key, this);
    }
  }},
  // Implements a map much like the one for Array.prototype.map.
  // Returns a normal Array instance.
  map: {value: function map(callback, thisObject) {
    var keys = Object.keys(this),
        length = keys.length,
        accum = new Array(length);
    for (var i = 0; i < length; i++) {
      var key = keys[i];
      accum[i] = callback.call(thisObject, this[key], key, this);
    }
    return accum;
  }}
});
Object.freeze(Hash);

usage.js

var obj = Hash.new({name:"Tim", age:28});

obj.forEach(function (value, key) {
  console.log("%s %s", key, value);
});
// name Tim
// age 28

console.dir(obj.map(function (value, key) {
  return key + " = " + value;
}));
// [ 'name = Tim', 'age = 28' ]

console.dir(obj);
// { name: 'Tim', age: 28 }

console.log(JSON.stringify(obj));
// {"name":"Tim","age":28}

console.dir(obj instanceof Object);
// true

console.dir(Object.prototype.isPrototypeOf(obj));
// true

console.dir(Hash.isPrototypeOf(obj));
// true