public function consume_range($chars)
	{
		if ($len = strspn($this->data, $chars, $this->position))
		{
			$data = substr($this->data, $this->position, $len);
			$this->consumed .= $data;
			$this->position += $len;
			return $data;
		}
		else
		{
			return false;
		}
	}