Memoization implementations

memoizes.js

// Underscore.js
_.memoize = function(func, hasher) {
  var memoize = function(key) {
    var cache = memoize.cache;
    var address = '' + (hasher ? hasher.apply(this, arguments) : key);
    if (!_.has(cache, address)) cache[address] = func.apply(this, arguments);
    return cache[address];
  };
  memoize.cache = {};
  return memoize;
};

// Lodash.js
function MemCache() {
    this.__data__ = {};
}
function memGet(key) {
  return this.__data__[key];
}
function memHas(key) {
  return key != '__proto__' && hasOwnProperty.call(this.__data__, key);
}
function memSet(key, value) {
  if (key != '__proto__') {
    this.__data__[key] = value;
  }
  return this;
}
MemCache.prototype.get = memGet;
MemCache.prototype.has = memHas;
MemCache.prototype.set = memSet;

function memoize(func, resolver) {
  if (!isFunction(func) || (resolver && !isFunction(resolver))) {
    throw new TypeError(FUNC_ERROR_TEXT);
  }
  var memoized = function() {
    var cache = memoized.cache,
        key = resolver ? resolver.apply(this, arguments) : arguments[0];

    if (cache.has(key)) {
      return cache.get(key);
    }
    var result = func.apply(this, arguments);
    cache.set(key, result);
    return result;
  };
  memoized.cache = new memoize.Cache;
  return memoized;
}

memoize.Cache = MemCache;

// Addy Osmani's memoize.js
// http://addyosmani.com/blog/faster-javascript-memoization/
var memoize = function(func) {
  var stringifyJson = JSON.stringify,
      cache = {};

  var cachedfun = function() {
      var hash = stringifyJson(arguments);
      return (hash in cache) ? cache[hash] : cache[hash] = func.apply(this, arguments);
  };

  cachedfun.__cache = (function() {
      cache.remove || (cache.remove = function() {
          var hash = stringifyJson(arguments);
          return (delete cache[hash]);
      });
      return cache;
  }).call(this);

  return cachedfun;
};