private methods and vars

JS Singleton

//http://www.crockford.com/javascript/little.html

var singleton = (function(){
   var privateHello = "hello";
   function privateFunction(something){
     privateHello = privateHello + " " + something;
   }
   return {
             changeSomething: function(a){
                   privateFunction(a);
              },
             logSomething: function(){
                 console.log(privateHello);
               }
           }
}());

function gizmo(id, secret){
   secret = secret || {};
   secret.id = id;
   return {
            toString: function() {
                        return "gizmo" + secret.id;
                      }
          }
}

function hoozit(id){
    var secret = {};
    var that = gizmo(id, secret);
    that.test = function(testId){
       return testId === secret.id;
     };
     return that;
}

var memoizer(memo, formula) {
   var recur = function(n){
      var result = memo[n];
      if (typeof result !== 'number') {
         result = formula(recur, n) {
            memo[n] = result;
         }
      }
      return result;
   }
   return recur;
}

var fibSeq = memoizer([1,1], function(recur, n) {
   return n * recur(n - 1);
});