طریقه پیاده سازی کلاس لینک لیست در php

[hard engineer]

با عرض سلام
من پروژه ای دارم که باید کلاس لینک لیست رو در php پیاده سازی کنم.پیاده سازی این ساختمان داده در C++‎‎ به صورت زیر هست:
class node{
private:
int data;
node *next;
}
همانطور که ملاحظه کردین در این کد از اشاره گر هم استفاده شده.
لطفا راهنمایی کنین.
تشکر

[arash691]

<?php


class ListNode
{
/* Data to hold */
public $data;

/* Link to next node */
public $next;


/* Node constructor */
function __construct($data)
{
$this->data = $data;
$this->next = NULL;
}

function readNode()
{
return $this->data;
}
}


class LinkList
{
/* Link to the first node in the list */
private $firstNode;

/* Link to the last node in the list */
private $lastNode;

/* Total nodes in the list */
private $count;



/* List constructor */
function __construct()
{
$this->firstNode = NULL;
$this->lastNode = NULL;
$this->count = 0;
}

public function isEmpty()
{
return ($this->firstNode == NULL);
}

public function insertFirst($data)
{
$link = new ListNode($data);
$link->next = $this->firstNode;
$this->firstNode = &$link;

/* If this is the first node inserted in the list
then set the lastNode pointer to it.
*/
if($this->lastNode == NULL)
$this->lastNode = &$link;

$this->count++;
}

public function insertLast($data)
{
if($this->firstNode != NULL)
{
$link = new ListNode($data);
$this->lastNode->next = $link;
$link->next = NULL;
$this->lastNode = &$link;
$this->count++;
}
else
{
$this->insertFirst($data);
}
}

public function deleteFirstNode()
{
$temp = $this->firstNode;
$this->firstNode = $this->firstNode->next;
if($this->firstNode != NULL)
$this->count--;

return $temp;
}

public function deleteLastNode()
{
if($this->firstNode != NULL)
{
if($this->firstNode->next == NULL)
{
$this->firstNode = NULL;
$this->count--;
}
else
{
$previousNode = $this->firstNode;
$currentNode = $this->firstNode->next;

while($currentNode->next != NULL)
{
$previousNode = $currentNode;
$currentNode = $currentNode->next;
}

$previousNode->next = NULL;
$this->count--;
}
}
}

public function deleteNode($key)
{
$current = $this->firstNode;
$previous = $this->firstNode;

while($current->data != $key)
{
if($current->next == NULL)
return NULL;
else
{
$previous = $current;
$current = $current->next;
}
}

if($current == $this->firstNode)
{
if($this->count == 1)
{
$this->lastNode = $this->firstNode;
}
$this->firstNode = $this->firstNode->next;
}
else
{
if($this->lastNode == $current)
{
$this->lastNode = $previous;
}
$previous->next = $current->next;
}
$this->count--;
}

public function find($key)
{
$current = $this->firstNode;
while($current->data != $key)
{
if($current->next == NULL)
return null;
else
$current = $current->next;
}
return $current;
}

public function readNode($nodePos)
{
if($nodePos <= $this->count)
{
$current = $this->firstNode;
$pos = 1;
while($pos != $nodePos)
{
if($current->next == NULL)
return null;
else
$current = $current->next;

$pos++;
}
return $current->data;
}
else
return NULL;
}

public function totalNodes()
{
return $this->count;
}

public function readList()
{
$listData = array();
$current = $this->firstNode;

while($current != NULL)
{
array_push($listData, $current->readNode());
$current = $current->next;
}
return $listData;
}

public function reverseList()
{
if($this->firstNode != NULL)
{
if($this->firstNode->next != NULL)
{
$current = $this->firstNode;
$new = NULL;

while ($current != NULL)
{
$temp = $current->next;
$current->next = $new;
$new = $current;
$current = $temp;
}
$this->firstNode = $new;
}
}
}
}

?>