ReadonlyapplyProtected ReadonlyarityReadonlyoperatorProtected ReadonlyoverloadsReadonlysupportsThe arity of the function will be checked when parsing and preparing a function. This allows us to check if the query is correct even before we process any bindings.
ProtectedhandleStaticcleanStaticflagQStaticflagX
https://www.w3.org/TR/sparql11-query/#func-regex