| from functools import reduce | |
| from typing import Callable | |
| def combine[T](items: list[T], combine_fn: Callable[[T, T], T | None]) -> list[T]: | |
| def fold_fn(acc: list[T], item: T) -> list[T]: | |
| if not acc: | |
| return [item] | |
| combined = combine_fn(acc[-1], item) | |
| if combined is not None: | |
| return [*acc[:-1], combined] | |
| return [*acc, item] | |
| result = reduce(fold_fn, items, []) | |
| return result | |