public function commaSeparated($string, $type = 'alphanumeric', $delimiter = ',')
	{
		if (empty($string))
			return false;

		// This is why we can't have nice things...
		$t = isset($this->_commaCases[$type]) ? $this->_commaCases[$type] : $this->_commaCases['alphanumeric'];

		return empty($string) ? false : implode($delimiter, array_filter(explode($delimiter, preg_replace(
			array(
				'/[^'. $t .',]/',
				'/(?<='. $delimiter .')'. $delimiter .'+/',
				'/^'. $delimiter .'+/',
				'/'. $delimiter .'+$/'
			), '', $string
		))));
	}