public function getRegexp()
	{
		$hosts = [];
		foreach ($this->items as $host)
		{
			$hosts[] = $this->normalizeHostmask($host);
		}

		$regexp = RegexpBuilder::fromList(
			$hosts,
			[
				// Asterisks * are turned into a catch-all expression, while ^ and $ are preserved
				'specialChars' => [
					'*' => '.*',
					'^' => '^',
					'$' => '$'
				]
			]
		);

		return '/' . $regexp . '/DSis';
	}