Lifting binary operations, e.g. T+T → Option<T> + Option<T>

language design
23

Is there a simple way today to get the other kind lift, which turns a binary operation on T into a binary operation on Option<T>, respecting the new identity element None?

fn lift<T, F: FnOnce(T, T) -> T>(
    f: F, left: Option<T>, right: Option<T>) -> Option<T> {
    match (left, right) {
        (None, right) => right,
        (left, None) => left,
        (Some(left), Some(right)) => Some(f(left, right)),
    }
}

This does the right thing for std::cmp::min, std::cmp::max. I think this is the expected lift from a semigroup T into a monoid T ⊍ {None}. But it is curiously absent from Haskell, Standard ML, and Java.

This is also the lift you need if you want to fold on a binary operation which does not have a natural zero element to start with, so the omission is even more curious.

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