$data = [<|optionalValue: Just(4), missingValue: -1|>,
         <|optionalValue: Nothing(int32?), missingValue: -2|>,
         <|optionalValue: Just(404), missingValue: -3|>,
         <|optionalValue: Nothing(int32?), missingValue: -4|>,];


$f = ($x) -> {
    return $x * 2;
};

SELECT YQL::IfPresent(optionalValue, $f, missingValue) FROM as_table($data);