// -- Additional functions

// Array.forEach( function ) - Apply a function to each element
Array.prototype.forEach = function( f ) {
 var i = this.length, j, l = this.length;
 for( i=0; i<l; i++ ) { if( ( j = this[i] ) ) { f( j ); } }
};

// Array.indexOf(value, begin, strict) - Return index of the first element that matches value
Array.prototype.indexOf = function(v, b, s) {
  for(var i = +b || 0, l = this.length; i<l; i++){
    if((s && this[i]===v) || (this[i]==v)){ return i; }
  }
  return -1;
};

// Array.indexOfA( value, begin, strict, subObj) - Return index of the first element that matches value of subO-object
Array.prototype.indexOfA = function( v, b, s, subObj) {
  for(var i = +b || 0, l = this.length; i < l; i++){
    if(eval("this[i]." + subObj)===v || s && eval("this[i]." + subObj)==v){return i;}
  }
  return -1;
};


// Array.insert( index, value ) - Insert value at index, without overwriting existing keys
Array.prototype.insert = function( i, v ) {
 if( i>=0 ) {
  var a = this.slice(), b = a.splice( i );
  a[i] = v;
  return a.concat( b );
 }
};

// Array.lastIndexOf( value, begin, strict ) - Return index of the last element that matches value
Array.prototype.lastIndexOf = function( v, b, s ) {
 b = +b || 0;
 var i = this.length; while(i-->b) {
  if(this[i]===v || s && this[i]==v) { return i; }
 }
 return -1;
};

// Array.random( range ) - Return a random element, optionally up to or from range
Array.prototype.random = function( r ) {
 var i = 0, l = this.length;
 if( !r ) { r = this.length; }
 else if( r > 0 ) { r = r % l; }
 else { i = r; r = l + r % l; }
 return this[ Math.floor( r * Math.random() - i ) ];
};

// Array.shuffle( deep ) - Randomly interchange elements
Array.prototype.shuffle = function( b ) {
 var i = this.length, j, t;
 while( i ) {
  j = Math.floor( ( i-- ) * Math.random() );
  t = b && typeof this[i].shuffle!=='undefined' ? this[i].shuffle() : this[i];
  this[i] = this[j];
  this[j] = t;
 }
 return this;
};

//### Array.unique(strict) - Remove duplicate values
Array.prototype.unique = function(b){
  var a = [], i, l = this.length;
  for(i=0; i<l; i++){
    if(a.indexOf(this[i], 0, b) < 0){
      a.push(this[i]);
    }
  }
  return a;
};

//### Array.uniqueA(subObj) - Remove duplicate values by sub-object
Array.prototype.uniqueA = function(subObj){
  var a = [], i, l = this.length;
  for(i=0; i<l; i++){
    if(a.indexOfA(this[i], 0, b, subObj) < 0){
      a.push(this[i]);
    }
  }
  return a;
};

// Array.walk() - Change each value according to a callback function
Array.prototype.walk = function( f ) {
 var a = [], i = this.length;
 while(i--) { a.push( f( this[i] ) ); }
 return a.reverse();
};