PREFIX : <http://example.org/>
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
SELECT (STRLEN(?uuid) AS ?length)
WHERE {
	BIND(STRUUID() AS ?uuid)
	FILTER(ISLITERAL(?uuid) && REGEX(?uuid, "^[0-9A-F]{8}-[0-9A-F]{4}-[0-9A-F]{4}-[0-9A-F]{4}-[0-9A-F]{12}$", "i"))
}
