What’s the right name for this function? It’s like `fold`, but the `operation` is allowed to return ...

# naming

[Sam]

What’s the right name for this function? It’s like fold, but the operation is allowed to return null, in which case the whole thing exits early with a null return value.

private inline fun <T, R> Iterable<T>.fold2(initial: R, operation: (acc: R, T) -> R?): R? =
    fold<T, R?>(initial) { acc, element -> operation(acc ?: return null, element) }