OrderQuery::explodeFilterKey

static function explodeFilterKey($key)
{
	preg_match('/^([!+*]{0,1})([<=>@%~?]{0,2})(.*)$/', $key, $matches);

	return array(
		'modifier' => $matches[1], // can be ""
		'operator' => $matches[2], // can be ""
		'alias'    => $matches[3], // can be ""
	);
}