كيف يمكن معرفة موقع الحرف في الكلمة ؟

وأنا أبحث في الموضوع وجدت هذا الكود ولكن بلغة php

ولا أعلم إن كان يفيد في الفكرة

<?php
/**
 * word2uni
 * This code is a part of aCAPTCHA project, This copyright notice MUST stay intact for use
 * @package aCAPTCHA 
 * @author Abd Allatif Eymsh
 * @copyright (c) 2012
 * @license http://opensource.org/licenses/gpl-license.php GNU Public License
 */
function word2uni($word)
{

	$new_word = array();
	$char_type = array();
	$isolated_chars = array('ا', 'د', 'ذ', 'أ', 'آ', 'ر', 'ؤ', 'ء', 'ز', 'و', 'ى', 'ة');

	$all_chars = array
		(
			'ا' => array(

				'middle'		=>   'ﺎ',

				'isolated'		=>   'ﺍ'
				),

			'ؤ' => array(

				'middle'		=>   'ﺅ',

				'isolated'		=>   'ﺆ'
				),
			'ء' => array(
				'middle'		=>   'ﺀ',
				'isolated'		=>   'ﺀ'
				),
			'أ' => array(

				'middle'		=>   'ﺄ',

				'isolated'		=>   'ﺃ'
				),
			'آ' => array(

				'middle'		=>   'ﺂ',

				'isolated'		=>   'ﺁ'
				),
			'ى' => array(

				'middle'		=>   'ﻰ',

				'isolated'		=>   'ﻯ'
				),
			'ب' => array(
				'beginning'		=>   'ﺑ',
				'middle'		=>   'ﺒ',
				'end'			=>   'ﺐ',
				'isolated'		=>   'ﺏ'
				),
			'ت' => array(
				'beginning'		=>   'ﺗ',
				'middle'		=>   'ﺘ',
				'end'			=>   'ﺖ',
				'isolated'		=>   'ﺕ'
				),
			'ث' => array(
				'beginning'		=>   'ﺛ',
				'middle'		=>   'ﺜ',
				'end'			=>   'ﺚ',
				'isolated'		=>   'ﺙ'
				),
			'ج' => array(
				'beginning'		=>   'ﺟ',
				'middle'		=>   'ﺠ',
				'end'			=>   'ﺞ',
				'isolated'		=>   'ﺝ'
				),
			'ح' => array(
				'beginning'		=>   'ﺣ',
				'middle'		=>   'ﺤ',
				'end'			=>   'ﺢ',
				'isolated'		=>   'ﺡ'
				),
			'خ' => array(
				'beginning'		=>   'ﺧ',
				'middle'		=>   'ﺨ',
				'end'			=>   'ﺦ',
				'isolated'		=>   'ﺥ'
				),
			'د' => array(
				'middle'		=>   'ﺪ',
				'isolated'		=>   'ﺩ'
				),
			'ذ' => array(
				'middle'		=>   'ﺬ',
				'isolated'		=>   'ﺫ'
				),
			'ر' => array(
				'middle'		=>   'ﺮ',
				'isolated'		=>   'ﺭ'
				),
			'ز' => array(
				'middle'		=>   'ﺰ',
				'isolated'		=>   'ﺯ'
				),
			'س' => array(
				'beginning'		=>   'ﺳ',
				'middle'		=>   'ﺴ',
				'end'			=>   'ﺲ',
				'isolated'		=>   'ﺱ'
				),
			'ش' => array(
				'beginning'		=>   'ﺷ',
				'middle'		=>   'ﺸ',
				'end'			=>   'ﺶ',
				'isolated'		=>   'ﺵ'
				),
			'ص' => array(
				'beginning'		=>   'ﺻ',
				'middle'		=>   'ﺼ',
				'end'			=>   'ﺺ',
				'isolated'		=>   'ﺹ'
				),
			'ض' => array(
				'beginning'		=>   'ﺿ',
				'middle'		=>   'ﻀ',
				'end'			=>   'ﺾ',
				'isolated'		=>   'ﺽ'
				),
			'ط' => array(
				'beginning'		=>   'ﻃ',
				'middle'		=>   'ﻄ',
				'end'			=>   'ﻂ',
				'isolated'		=>   'ﻁ'
				),
			'ظ' => array(
				'beginning'		=>   'ﻇ',
				'middle'		=>   'ﻈ',
				'end'			=>   'ﻆ',
				'isolated'		=>   'ﻅ'
				),
			'ع' => array(
				'beginning'		=>   'ﻋ',
				'middle'		=>   'ﻌ',
				'end'			=>   'ﻊ',
				'isolated'		=>   'ﻉ'
				),
			'غ' => array(
				'beginning'		=>   'ﻏ',
				'middle'		=>   'ﻐ',
				'end'			=>   'ﻎ',
				'isolated'		=>   'ﻍ'
				),
			'ف' => array(
				'beginning'		=>   'ﻓ',
				'middle'		=>   'ﻔ',
				'end'			=>   'ﻒ',
				'isolated'		=>   'ﻑ'
				),
			'ق' => array(
				'beginning'		=>   'ﻗ',
				'middle'		=>   'ﻘ',
				'end'			=>   'ﻖ',
				'isolated'		=>   'ﻕ'
				),
			'ك' => array(
				'beginning'		=>   'ﻛ',
				'middle'		=>   'ﻜ',
				'end'			=>   'ﻚ',
				'isolated'		=>   'ﻙ'
				),
			'ل' => array(
				'beginning'		=>   'ﻟ',
				'middle'		=>   'ﻠ',
				'end'			=>   'ﻞ',
				'isolated'		=>   'ﻝ'
				),
			'م' => array(
				'beginning'		=>   'ﻣ',
				'middle'		=>   'ﻤ',
				'end'			=>   'ﻢ',
				'isolated'		=>   'ﻡ'
				),
			'ن' => array(
				'beginning'		=>   'ﻧ',
				'middle'		=>   'ﻨ',
				'end'			=>   'ﻦ',
				'isolated'		=>   'ﻥ'
				),
			'ه' => array(
				'beginning'		=>   'ﻫ',
				'middle'		=>   'ﻬ',
				'end'			=>   'ﻪ',
				'isolated'		=>   'ﻩ'
				),
			'و' => array(
				'middle'		=>   'ﻮ',
				'isolated'		=>   'ﻭ'
				),
			'ي' => array(
				'beginning'		=>   'ﻳ',
				'middle'		=>   'ﻴ',
				'end'			=>   'ﻲ',
				'isolated'		=>   'ﻱ'
				),
			'ئ' => array(
				'beginning'		=>   'ﺋ',
				'middle'		=>   'ﺌ',
				'end'			=>   'ﺊ',
				'isolated'		=>   'ﺉ'
				),
			'ة' => array(
				'middle'		=>   'ﺔ',
				'isolated'		=>   'ﺓ'
				)
		);

	if(in_array($word[0].$word[1], $isolated_chars))
	{
		$new_word[] = $all_chars[$word[0].$word[1]]['isolated'];
		$char_type[] = 'not_normal';
	}
	else
	{
		$new_word[] = $all_chars[$word[0].$word[1]]['beginning'];
		$char_type[] = 'normal';
	}

	if(strlen($word) > 4)
	{
		if($char_type[0] == 'not_normal')

		{
			if(in_array($word[2].$word[3], $isolated_chars))
			{
				$new_word[] = $all_chars[$word[2].$word[3]]['isolated'];
				$char_type[] = 'not_normal';
			}
			else
			{

				$new_word[] = $all_chars[$word[2].$word[3]]['beginning'];
				$char_type[] = 'normal';
			}
		}
		else
		{
			$new_word[] = $all_chars[$word[2].$word[3]]['middle'];
			$chars_statue[] = 'middle';

			if(in_array($word[2].$word[3], $isolated_chars))
			{
				$char_type[] = 'not_normal';
			}
			else
			{
				$char_type[] = 'normal';
			}
		}
		$x = 4;
	}
	else
	{
		$x = 2;	
	}

	for($x=4;$x< (strlen($word)-4) ;$x++)
	{
		if($char_type[count($char_type)-1] == 'not_normal' AND $x %2 == 0)
		{
			if(in_array($word[$x].$word[$x+1], $isolated_chars))
			{

				$new_word[] = $all_chars[$word[$x].$word[$x+1]]['isolated'];
				$char_type[] = 'not_normal';
			}
			else
			{

				$new_word[] = $all_chars[$word[$x].$word[$x+1]]['beginning'];
				$char_type[] = 'normal';
			}
		}
		elseif($char_type[count($char_type)-1] == 'normal' AND $x %2 == 0)
		{

			if(in_array($word[$x].$word[$x+1], $isolated_chars))
			{

				$new_word[] = $all_chars[$word[$x].$word[$x+1]]['middle'];
				$char_type[] = 'not_normal';
			}
			else
			{

				$new_word[] = $all_chars[$word[$x].$word[$x+1]]['middle'];
				$char_type[] = 'normal';
			}
		}

	}
	if(strlen($word)>6)
	{
		if($char_type[count($char_type)-1] == 'not_normal')
		{
			if(in_array($word[$x].$word[$x+1], $isolated_chars))
			{

				$new_word[] = $all_chars[$word[$x].$word[$x+1]]['isolated'];
				$char_type[] = 'not_normal';
			}
			else
			{

				if($word[strlen($word)-2].$word[strlen($word)-1] == 'ء')
				{
					$new_word[] = $all_chars[$word[$x].$word[$x+1]]['isolated'];
					$char_type[] = 'normal';
				}
				else
				{
					$new_word[] = $all_chars[$word[$x].$word[$x+1]]['beginning'];
					$char_type[] = 'normal';
				}

			}

			$x += 2;
		}
		elseif($char_type[count($char_type)-1] == 'normal')
		{

			if(in_array($word[$x].$word[$x+1], $isolated_chars))
			{

				$new_word[] = $all_chars[$word[$x].$word[$x+1]]['middle'];
				$char_type[] = 'not_normal';
			}
			else
			{

				$new_word[] = $all_chars[$word[$x].$word[$x+1]]['middle'];
				$char_type[] = 'normal';
			}

			$x += 2;
		}


	}

	if($char_type[count($char_type)-1] == 'not_normal')
	{

		if(in_array($word[$x].$word[$x+1], $isolated_chars))
		{		

			$new_word[] = $all_chars[$word[$x].$word[$x+1]]['isolated'];

		}
		else
		{
			$new_word[] = $all_chars[$word[$x].$word[$x+1]]['isolated'];

		}

	}
	else
	{
		if(in_array($word[$x].$word[$x+1], $isolated_chars))
		{

			$new_word[] = $all_chars[$word[$x].$word[$x+1]]['middle'];

		}
		else
		{

			$new_word[] = $all_chars[$word[$x].$word[$x+1]]['end'];

		}
	}

	return implode('',array_reverse($new_word));
}
?>