/// polyfills.js

if (!Array.prototype.indexOf) {
    Array.prototype.indexOf = function (searchElement /*, fromIndex */ ) {
        "use strict";
        if (this === void 0 || this === null) {
            throw new TypeError();
        }
        var t = Object(this);
        var len = t.length >>> 0;
        if (len === 0) {
            return -1;
        }
        var n = 0;
        if (arguments.length > 0) {
            n = Number(arguments[1]);
            if (n !== n) { // shortcut for verifying if it's NaN
                n = 0;
            } else if (n !== 0 && n !== Infinity && n !== -Infinity) {
                n = (n > 0 || -1) * Math.floor(Math.abs(n));
            }
        }
        if (n >= len) {
            return -1;
        }
        var k = n >= 0 ? n : Math.max(len - Math.abs(n), 0);
        for (; k < len; k++) {
            if (k in t && t[k] === searchElement) {
                return k;
            }
        }
        return -1;
    }
}

if (!Array.prototype.lastIndexOf)
{
  Array.prototype.lastIndexOf = function(searchElement /*, fromIndex*/)
  {
    "use strict";

    if (this === void 0 || this === null)
      throw new TypeError();

    var t = Object(this);
    var len = t.length >>> 0;
    if (len === 0)
      return -1;

    var n = len;
    if (arguments.length > 1)
    {
      n = Number(arguments[1]);
      if (n !== n)
        n = 0;
      else if (n !== 0 && n !== (1 / 0) && n !== -(1 / 0))
        n = (n > 0 || -1) * Math.floor(Math.abs(n));
    }

    var k = n >= 0
          ? Math.min(n, len - 1)
          : len - Math.abs(n);

    for (; k >= 0; k--)
    {
      if (k in t && t[k] === searchElement)
        return k;
    }
    return -1;
  };
}

if (!Array.prototype.filter)
{
  Array.prototype.filter = function(fun /*, thisp */)
  {
    "use strict";

    if (this === void 0 || this === null)
      throw new TypeError();

    var t = Object(this);
    var len = t.length >>> 0;
    if (typeof fun !== "function")
      throw new TypeError();

    var res = [];
    var thisp = arguments[1];
    for (var i = 0; i < len; i++)
    {
      if (i in t)
      {
        var val = t[i]; // in case fun mutates this
        if (fun.call(thisp, val, i, t))
          res.push(val);
      }
    }

    return res;
  };
}

// Production steps of ECMA-262, Edition 5, 15.4.4.18
// Reference: http://es5.github.com/#x15.4.4.18
if ( !Array.prototype.forEach ) {

  Array.prototype.forEach = function( callback, thisArg ) {

    var T, k;

    if ( this == null ) {
      throw new TypeError( " this is null or not defined" );
    }

    // 1. Let O be the result of calling ToObject passing the |this| value as the argument.
    var O = Object(this);

    // 2. Let lenValue be the result of calling the Get internal method of O with the argument "length".
    // 3. Let len be ToUint32(lenValue).
    var len = O.length >>> 0; // Hack to convert O.length to a UInt32

    // 4. If IsCallable(callback) is false, throw a TypeError exception.
    // See: http://es5.github.com/#x9.11
    if ( {}.toString.call(callback) != "[object Function]" ) {
      throw new TypeError( callback + " is not a function" );
    }

    // 5. If thisArg was supplied, let T be thisArg; else let T be undefined.
    if ( thisArg ) {
      T = thisArg;
    }

    // 6. Let k be 0
    k = 0;

    // 7. Repeat, while k < len
    while( k < len ) {

      var kValue;

      // a. Let Pk be ToString(k).
      //   This is implicit for LHS operands of the in operator
      // b. Let kPresent be the result of calling the HasProperty internal method of O with argument Pk.
      //   This step can be combined with c
      // c. If kPresent is true, then
      if ( k in O ) {

        // i. Let kValue be the result of calling the Get internal method of O with argument Pk.
        kValue = O[ k ];

        // ii. Call the Call internal method of callback with T as the this value and
        // argument list containing kValue, k, and O.
        callback.call( T, kValue, k, O );
      }
      // d. Increase k by 1.
      k++;
    }
    // 8. return undefined
  };
}

if (!Array.prototype.every)
{
  Array.prototype.every = function(fun /*, thisp */)
  {
    "use strict";

    if (this === void 0 || this === null)
      throw new TypeError();

    var t = Object(this);
    var len = t.length >>> 0;
    if (typeof fun !== "function")
      throw new TypeError();

    var thisp = arguments[1];
    for (var i = 0; i < len; i++)
    {
      if (i in t && !fun.call(thisp, t[i], i, t))
        return false;
    }

    return true;
  };
}

// Production steps of ECMA-262, Edition 5, 15.4.4.19
// Reference: http://es5.github.com/#x15.4.4.19
if (!Array.prototype.map) {
  Array.prototype.map = function(callback, thisArg) {

    var T, A, k;

    if (this == null) {
      throw new TypeError(" this is null or not defined");
    }

    // 1. Let O be the result of calling ToObject passing the |this| value as the argument.
    var O = Object(this);

    // 2. Let lenValue be the result of calling the Get internal method of O with the argument "length".
    // 3. Let len be ToUint32(lenValue).
    var len = O.length >>> 0;

    // 4. If IsCallable(callback) is false, throw a TypeError exception.
    // See: http://es5.github.com/#x9.11
    if ({}.toString.call(callback) != "[object Function]") {
      throw new TypeError(callback + " is not a function");
    }

    // 5. If thisArg was supplied, let T be thisArg; else let T be undefined.
    if (thisArg) {
      T = thisArg;
    }

    // 6. Let A be a new array created as if by the expression new Array(len) where Array is
    // the standard built-in constructor with that name and len is the value of len.
    A = new Array(len);

    // 7. Let k be 0
    k = 0;

    // 8. Repeat, while k < len
    while(k < len) {

      var kValue, mappedValue;

      // a. Let Pk be ToString(k).
      //   This is implicit for LHS operands of the in operator
      // b. Let kPresent be the result of calling the HasProperty internal method of O with argument Pk.
      //   This step can be combined with c
      // c. If kPresent is true, then
      if (k in O) {

        // i. Let kValue be the result of calling the Get internal method of O with argument Pk.
        kValue = O[ k ];

        // ii. Let mappedValue be the result of calling the Call internal method of callback
        // with T as the this value and argument list containing kValue, k, and O.
        mappedValue = callback.call(T, kValue, k, O);

        // iii. Call the DefineOwnProperty internal method of A with arguments
        // Pk, Property Descriptor {Value: mappedValue, Writable: true, Enumerable: true, Configurable: true},
        // and false.

        // In browsers that support Object.defineProperty, use the following:
        // Object.defineProperty(A, Pk, { value: mappedValue, writable: true, enumerable: true, configurable: true });

        // For best browser support, use the following:
        A[ k ] = mappedValue;
      }
      // d. Increase k by 1.
      k++;
    }

    // 9. return A
    return A;
  };      
}

if (!Array.prototype.some) {
  Array.prototype.some = function(fun /*, thisp */) {
    "use strict";

    if (this === void 0 || this === null)
      throw new TypeError();

    var t = Object(this);
    var len = t.length >>> 0;
    if (typeof fun !== "function")
      throw new TypeError();

    var thisp = arguments[1];
    for (var i = 0; i < len; i++)
    {
      if (i in t && fun.call(thisp, t[i], i, t))
        return true;
    }

    return false;
  };
}

if ( !Array.prototype.reduce ) {
  Array.prototype.reduce = function reduce(accumulator){
        var i, l = this.length, curr;
        
        if(typeof accumulator !== "function") // ES5 : "If IsCallable(callbackfn) is false, throw a TypeError exception."
          throw new TypeError("First argument is not callable");

        if((l == 0 || l === null) && (arguments.length <= 1))// == on purpose to test 0 and false.
          throw new TypeError("Array length is 0 and no second argument");
        
        if(arguments.length <= 1){
          curr = this[0]; // Increase i to start searching the secondly defined element in the array
          i = 1; // start accumulating at the second element
        }
        else{
          curr = arguments[1];
        }
        
        for(i = i || 0 ; i < l ; ++i){
          if(i in this)
            curr = accumulator.call(undefined, curr, this[i], i, this);
        }
        
        return curr;
    };
}

if (!Array.prototype.reduceRight) {
  Array.prototype.reduceRight = function(callbackfn /*, initialValue */) {
    "use strict";

    if (this === void 0 || this === null)
      throw new TypeError();

    var t = Object(this);
    var len = t.length >>> 0;
    if (typeof callbackfn !== "function")
      throw new TypeError();

    // no value to return if no initial value, empty array
    if (len === 0 && arguments.length === 1)
      throw new TypeError();

    var k = len - 1;
    var accumulator;
    if (arguments.length >= 2)
    {
      accumulator = arguments[1];
    }
    else
    {
      do
      {
        if (k in this)
        {
          accumulator = this[k--];
          break;
        }

        // if array contains no values, no initial value to return
        if (--k < 0)
          throw new TypeError();
      }
      while (true);
    }

    while (k >= 0)
    {
      if (k in t)
        accumulator = callbackfn.call(undefined, accumulator, t[k], k, t);
      k--;
    }

    return accumulator;
  };
}


object_keys = Object.keys || function(o) {
  if (o !== Object(o)) {
    throw new TypeError('Object.keys called on non-object');
  }

  var result = []
      ,p;

  for (p in o) {
    if (Object.prototype.hasOwnProperty.call(o,p)) {
      result.push(p);
    }
  }

  return result;
};  

// // if (!Object.prototype.values) {
// //   Object.prototype.values = function () {
// //     var result = [];

// //     for each (var v in this) {
// //       result.push(v);
// //     }

// //     return result;
// //   };
// // }