| # Copyright 2021 The Fuchsia Authors. All rights reserved. |
| # Use of this source code is governed by a BSD-style license that can be |
| # found in the LICENSE file. |
| """ |
| Utility functions for dealing with class members which are sets and lists. |
| """ |
| |
| from typing import Any |
| |
| __all__ = ["difference_field", "intersect_field"] |
| |
| |
| def intersect_field(item_a: Any, item_b: Any, field: str, result: Any) -> None: |
| """Set the named field in `result` if the value for that field is the same |
| in items A and B. |
| """ |
| value_a = getattr(item_a, field) |
| value_b = getattr(item_b, field) |
| if value_a == value_b: |
| setattr(result, field, value_a) |
| |
| |
| def difference_field(item_a: Any, item_b: Any, field: str, result: Any) -> None: |
| """Set the named field in `result` to the value from item_a if the value for that field is different |
| in items A and B. |
| """ |
| value_a = getattr(item_a, field) |
| value_b = getattr(item_b, field) |
| if value_a != value_b: |
| setattr(result, field, value_a) |
