Bit Manipulation Class - Using strings as a bitstring allowing for huge amount of toggles #Bits

Bitman.php

<?php
/*
 * Bitman.php
 * 
 * Copyright 2014 Luis "Laffin" Espinoza <laffintoo@gmail.com>
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 * MA 02110-1301, USA.
 * 
 * 
 */


/*
 * Class Bitman
 */
class Bitman
{
	public $bitstring;
	private $char_pos,$bit;
	/**
	 * Constructor of class bitfun.
	 *
	 * @return void
	 */
	public function __construct($bitstring=NULL)
	{
		if($bitstring==NULL) $bitstring=chr(0);
		$this->bitstring=$bitstring;
	}
	public function getBitString()
	{
		return $this->bitstring;
	}
	private function SetPos($position)
	{
		$this->char_pos=(int)($position / 8);
		$this->bit=$position % 8;
		if(strlen($this->bitstring)<$this->char_pos)
			$this->bitstring=$this->bitstring . str_repeat(chr(0),$this->char_pos - strlen($this->bitstring));
	}
	private function GetByte()
	{
		return ord(substr($this->bitstring,$this->char_pos,1));
	}
	function SetByte($char)
	{
		$this->bitstring[$this->char_pos] = chr($char);
	}
	
	public function Test($position)
	{
		$this->SetPos($position);
		return ($this->GetByte() & (1<<$this->bit))?1:0;
	}

	public function Set($position)
	{
		$this->SetPos($position);
		$this->SetByte($this->GetByte() | (1<<$this->bit));
	}

	public function Clear($position)
	{
		$this->SetPos($position);
		$this->SetByte($this->GetByte() & ~(1<<$this->bit));
	}

	public function Toggle($position)
	{
		$this->SetPos($position);
		$this->SetByte($this->GetByte() ^ (1<<$this->bit));
	}

}

$bs = new Bitman();
for($i=1;$i<255;$i+=2)
{
	$bs->Set($i);
}
echo strlen($bs->GetBitString()) .':' . var_export($bs->GetBitString(),1).PHP_EOL;
for($i=0;$i<255;$i++)
{
	echo $bs->Test($i);
}
echo PHP_EOL;