Macro downcast_integer_array

macro_rules! downcast_integer_array {
    ($values:ident => $e:expr, $($p:pat => $fallback:expr $(,)*)*) => { ... };
    (($($values:ident),+) => $e:expr, $($p:pat => $fallback:expr $(,)*)*) => { ... };
    ($($values:ident),+ => $e:block $($p:pat => $fallback:expr $(,)*)*) => { ... };
    (($($values:ident),+) => $e:block $($p:pat => $fallback:expr $(,)*)*) => { ... };
}

Given one or more expressions evaluating to an integer PrimitiveArray invokes the provided macro with the corresponding array, along with match statements for any non integer array types

fn print_integer(array: &dyn Array) {
    downcast_integer_array!(
        array => {
            for v in array {
                println!("{:?}", v);
            }
        }
        DataType::Utf8 => {
            for v in as_string_array(array) {
                println!("{:?}", v);
            }
        }
        t => println!("Unsupported datatype {}", t)
    )
}