Function string_to_array_column_args

datafusion/functions-nested/src/string.rs:446–496

(
    string_array: &StringArrType,
    delimiter_array: &ArrayRef,
    null_value_array: Option<&ArrayRef>,
    string_builder: StringBuilderType,
)

}

fn string_to_array_column_args<'a, StringArrType, StringBuilderType>(
    string_array: &StringArrType,
    delimiter_array: &ArrayRef,
    null_value_array: Option<&ArrayRef>,
    string_builder: StringBuilderType,
) -> Result<ArrayRef>
where
    StringArrType: StringArrayType<'a>,
    StringBuilderType: StringArrayBuilderType,
{
    let mut list_builder = ListBuilder::new(string_builder);

    for i in 0..string_array.len() {
        if string_array.is_null(i) {
            list_builder.append(false);
            continue;
        }

        let string = string_array.value(i);
        let delimiter = get_str_value(delimiter_array, i);
        let null_value = null_value_array.and_then(|arr| get_str_value(arr, i));

        match delimiter {
            Some("") => {
                if !string.is_empty() {
                    append_part(list_builder.values(), string, null_value);
                }
            }
            Some(delimiter) => {
                if !string.is_empty() {
                    for part in string.split(delimiter) {
                        append_part(list_builder.values(), part, null_value);
                    }
                }
            }
            None => {
                for (pos, c) in string.char_indices() {
                    append_part(
                        list_builder.values(),
                        &string[pos..pos + c.len_utf8()],
                        null_value,
                    );
                }
            }
        }

        list_builder.append(true);
    }

    Ok(Arc::new(list_builder.finish()) as ArrayRef)
}

/// Returns the string value at index `i` from a string array of any type.
fn get_str_value(array: &ArrayRef, i: usize) -> Option<&str> {