hash.js

function Hash(object){
  function hash(key, value){
    return (
      arguments.length === 2 ? hash.set(key, value) :
      arguments.length === 1 ? hash.get(key) :
      hash.index
    );
  };
  hash.index = {};
  for (var p in Hash.prototype) hash[p] = Hash.prototype[p];
  return hash.extend(object);
}

Hash.prototype.get = function get(key){
  return this.index[key];
};

Hash.prototype.set = function get(key, value){
  this.index[key] = value;
  return this;
};

Hash.prototype.extend = function extend(object){
  for (var p in object) this.index[p] = object[p];
  return this;
};

Hash.prototype.toObject = function toObject(){ return this.index; };

var things = new Hash({name:'fred'});

print( things('name') );
print( things().name );

things('foo', 'bar');
print( things('foo') );
print( things().foo );

things().foo = 'baz';
print( things('foo') );
print( things().foo );