Function struct_fields

arrow-json/src/reader/struct_array.rs:270–275

(data_type: &DataType)

}

fn struct_fields(data_type: &DataType) -> &Fields {
    match &data_type {
        DataType::Struct(f) => f,
        _ => unreachable!(),
    }
}

fn build_field_index(fields: &Fields) -> Option<HashMap<String, usize>> {
    // Heuristic threshold: for small field counts, linear scan avoids HashMap overhead.