jschallenge.js

function cache_store(callback,key,value){}
function cache_retrieve(callback,key) {}
function slow_function(callback,input){}
 
 
function memorize(callback, slow_function) {
  
  var self  = this, result;
  
  self.result = cache_retrieve(callback,slow_function);
  
  if(!self.result) 
  {
    self.result = function(cb, input){
      value = slow_function.call(self, cb, input);
      cache_store(self.callback,slow_function, value);
      return value;
    };
  
  } 
  
  return self.result; 
}
 
fast_function = memorise(slow_fucntion);

jschallenge_v2.js

function cache_store(callback,key,value){}
function cache_retrieve(callback,key) {}
function slow_function(callback,input){}
 
 
function memorize(slow_function) {
  
  var self  = this, result;
  
  cache_retrieve(function(value){
    self.result = value;
  },slow_function);
  
  if(!result) 
  {
    self.result = function(callback, input){
      value = slow_function.call(self, callback, input);
      cache_store(function(){},slow_function, value);
      return value;
    };
  
  } 
  
  return self.result; 
}
 
fast_function = memorise(slow_fucntion);