Function string_to_array_impl

src/expr/src/scalar/func/variadic.rs:1348–1383

(
    string: &str,
    delimiter: &str,
    null_string: Option<&'a str>,
    temp_storage: &'a RowArena,
)

}

fn string_to_array_impl<'a>(
    string: &str,
    delimiter: &str,
    null_string: Option<&'a str>,
    temp_storage: &'a RowArena,
) -> Result<Datum<'a>, EvalError> {
    let mut row = Row::default();
    let mut packer = row.packer();

    let result = string.split(delimiter);
    let found: Vec<&str> = if delimiter.is_empty() {
        result.filter(|s| !s.is_empty()).collect()
    } else {
        result.collect()
    };
    let array_dimensions = [ArrayDimension {
        lower_bound: 1,
        length: found.len(),
    }];

    if let Some(null_string) = null_string {
        let found_datums = found.into_iter().map(|chunk| {
            if chunk.eq(null_string) {
                Datum::Null
            } else {
                Datum::String(chunk)
            }
        });

        packer.try_push_array(&array_dimensions, found_datums)?;
    } else {
        packer.try_push_array(&array_dimensions, found.into_iter().map(Datum::String))?;
    }

    Ok(temp_storage.push_unary_row(row))
}

#[sqlfunc]
fn substr<'a>(s: &'a str, start: i32, length: OptionalArg<i32>) -> Result<&'a str, EvalError> {