@Override
public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
final QNm name = toQNm(exprs[0], qc, sc, false);
final long arity = toLong(exprs[1], qc);
if (arity < 0 || arity > Integer.MAX_VALUE) throw FUNCUNKNOWN_X.get(ii, name);
try {
final Expr lit = Functions.getLiteral(name, (int) arity, qc, sc, ii);
return lit == null ? null : lit.item(qc, ii);
} catch (final QueryException e) {
// function not found (in most cases: XPST0017)
return null;
}
}
