Function make_map_array_internal

datafusion/functions-nested/src/map.rs:477–501

Helper function to create MapArray from array of values to support arrays for Map scalar function ``` text Format of input KEYS and VALUES column keys values +---------------------+ +---------------------+ | +-----------------+ | | +-----------------+ | | | [k11, k12, k13] | | | | [v11, v12, v13] | | | +-----------------+ | | +-----------------+ | |

(
    keys: &ArrayRef,
    values: &ArrayRef,
)

/// +-----------+      +-----------+
/// ```text
fn make_map_array_internal<O: OffsetSizeTrait>(
    keys: &ArrayRef,
    values: &ArrayRef,
) -> Result<ColumnarValue> {
    // Save original data types and array length before list_to_arrays transforms them
    let keys_data_type = keys.data_type().clone();
    let values_data_type = values.data_type().clone();
    let original_len = keys.len(); // This is the number of rows in the input

    // Save the nulls bitmap from the original keys array (before list_to_arrays)
    // This tells us which MAP values are NULL (not which keys within maps are null)
    let nulls_bitmap = keys.nulls().cloned();

    let keys = list_to_arrays::<O>(keys);
    let values = list_to_arrays_skipping_null_rows::<O>(values, nulls_bitmap.as_ref());

    build_map_array(
        &keys,
        &values,
        &keys_data_type,
        &values_data_type,
        original_len,
        nulls_bitmap,
    )
}

/// Helper function specifically for FixedSizeList inputs
/// Similar to make_map_array_internal but uses fixed_size_list_to_arrays instead of list_to_arrays