array_contains.as

public function arrayContains(target:*, a:Array):Boolean {
  var doesNotContain:Boolean = false;
  return a.some(function(e:*, i:int, ar:Array):Boolean {
    var contains:Boolean = false;
    if (target is Array) {
       for(var ii:String in target) if (!arrayContains(target[ii], a)) doesNotContain = true;
       contains = doesNotContain? false:true;
    } else contains = (e == target);
    return contains;
  });
}