ArraySegment

<?PHP
    ABSTRACT CLASS ProtoArraySegment EXTENDS Proto
    {
        protected $__reference  = NULL;
        protected $__length = NULL;
        protected $__start  = NULL;
        protected $__first  = NULL;
        protected $__last   = NULL;

        public function __construct(ProtoArray &$array, $start = NULL, $length = NULL)
        {
            $this->__reference =& $array;

            $this->__start  = $start;
            $this->__length = $length;

            $this->__first = ($start === NULL)
                ? $array->bottom()
                : $start;

            $this->__last = ($length === NULL)
                ? $array->peek()
                : $array->peek($start + $length - 1);
        }
    }

    CLASS TArraySegment EXTENDS System\ProtoArraySegment IMPLEMENTS System\iIterator
    {
        const ITERATE_MODE_FIFO = 0x00000000;
        const ITERATE_MODE_LIFO = 0x00000001;

        private $__itMode   = 0;
        private $__index    = 0;
        public function __construct(TArray &$array, $start = NULL, $length = NULL)
        {
            if(NULL !== $start)
            {
                if(!is_integer($start))
                    throw new System\ArgumentException(System\E::ARGUMENT_EXPECTED_INTEGER);

                if($start < 0)
                    throw new System\ArgumentException(System\E::ARGUMENT_EXPECTED_INTEGER_NOT_POSITIVE_OR_ZERO,
                        ['value' => $start]);
            }

            if(NULL !== $length)
            {
                if(!is_integer($length))
                    throw new System\ArgumentException(System\E::ARGUMENT_EXPECTED_INTEGER);

                if($length <= 0)
                    throw new System\ArgumentException(System\E::ARGUMENT_EXPECTED_INTEGER_NOT_POSITIVE,
                        ['value' => $length]);
            }

            $this->__index = $start;
            parent::__construct($array, $start, $length);
        }

        final public function getIteratorMode()
        {
            return $this->__itMode;
        }

        final public function rewind()
        {
            return $this->__index = $this->__first;
        }

        final public function current()
        {
            return $this->__reference->offsetGet($this->__index);
        }

        final public function key()
        {
            return $this->__index;
        }

        final public function next()
        {
            return ++$this->__index;
        }

        final public function prev()
        {
        }

        final public function valid()
        {
            return $this->__reference->offsetExists($this->__index) && $this->__index >= $this->__first && $this->__index <= $this->__last;
        }
    }


$a = new tArray(["The", "quick", "brown", "fox", "jumps", "over", "the", "lazy", "dog"]);
$b = new tArraySegment($a, 2, 5); //"brown", "fox", "jumps", "over", "the"

$a[3] = 'LION';

var_dump($a);
var_dump($b); //"brown", "LION", "jumps", "over", "the"


foreach($b as $k => $v)
    var_dump($k.': '.$v);
?>
object(ILLI\System\Collection\TArray)#2 (4) {
  ["__itMode":"ILLI\System\Collection\TArray":private]=>
  int(0)
  ["__index":"ILLI\System\Collection\TArray":private]=>
  int(0)
  ["__array":"ILLI\System\ProtoArray":private]=>
  array(9) {
    [0]=>
    string(3) "The"
    [1]=>
    string(5) "quick"
    [2]=>
    string(5) "brown"
    [3]=>
    string(4) "LION"
    [4]=>
    string(5) "jumps"
    [5]=>
    string(4) "over"
    [6]=>
    string(3) "the"
    [7]=>
    string(4) "lazy"
    [8]=>
    string(3) "dog"
  }
  ["__protMode":"ILLI\System\ProtoArray":private]=>
  int(0)
}
object(ILLI\System\Collection\TArraySegment)#3 (7) {
  ["__itMode":"ILLI\System\Collection\TArraySegment":private]=>
  int(0)
  ["__index":"ILLI\System\Collection\TArraySegment":private]=>
  int(2)
  ["__reference":protected]=>
  &object(ILLI\System\Collection\TArray)#2 (4) {
    ["__itMode":"ILLI\System\Collection\TArray":private]=>
    int(0)
    ["__index":"ILLI\System\Collection\TArray":private]=>
    int(0)
    ["__array":"ILLI\System\ProtoArray":private]=>
    array(9) {
      [0]=>
      string(3) "The"
      [1]=>
      string(5) "quick"
      [2]=>
      string(5) "brown"
      [3]=>
      string(4) "LION"
      [4]=>
      string(5) "jumps"
      [5]=>
      string(4) "over"
      [6]=>
      string(3) "the"
      [7]=>
      string(4) "lazy"
      [8]=>
      string(3) "dog"
    }
    ["__protMode":"ILLI\System\ProtoArray":private]=>
    int(0)
  }
  ["__length":protected]=>
  int(5)
  ["__start":protected]=>
  int(2)
  ["__first":protected]=>
  int(2)
  ["__last":protected]=>
  int(6)
}
string(8) "2: brown"
string(7) "3: LION"
string(8) "4: jumps"
string(7) "5: over"
string(6) "6: the"