Exercise 07 - Caching Wrapper - v2

// A tracing version:

Function.prototype.cached = function(){
  var self = this, cache = {};
  return function(arg){
    if(arg in cache) {
      console.log('Cache hit for '+arg);
      return cache[arg];
    } else {
      console.log('Cache miss for '+arg);
      return cache[arg] = self(arg);
    }
  }
}


Math.sin = Math.sin.cached();
Math.sin(1); // Cache miss for 1
Math.sin(1); // Cache hit for 1