fn main() {
    let v1 = vec!(1, 2, 3);
    let v2 = vec!(4, 5, 6);
    let r = Vec::zipped(v1, v2, |a, b| a + b);
    println!("{}", r.len())
}

trait Foldable<T> {
    fn fold_right<R>(self, acc: R, f: impl Fn(R, &T) -> R) -> R;
}

impl <T> Foldable<T> for Vec<T> {
    fn fold_right<R>(self, acc: R, f: impl Fn(R, &T) -> R) -> R {
        return self.iter().fold(acc, |r, t| f(r, t));
    }
}

trait ZipResult<T> {
    fn zipped<A, B>(first: impl Foldable<A>, second: impl Foldable<B>, op: impl Fn(&A, &B) -> T) -> Self;
}

impl <T> ZipResult<T> for Vec<T> {
    fn zipped<A, B>(first: impl Foldable<A>, second: impl Foldable<B>, op: impl Fn(&A, &B) -> T) -> Vec<T> {
        return Vec::new();
    }
}

trait Zippable<A> {
    fn zip_with<B, T, R: ZipResult<T>>(self, other: impl Foldable<B>, f: impl Fn(&A, &B) -> T) -> R;
}

impl <F, A> Zippable<A> for F where F: Foldable<A> {
    fn zip_with<B, T, R: ZipResult<T>>(self, other: impl Foldable<B>, f: impl Fn(&A, &B) -> T) -> R {
        return R::zipped(self, other, f);
    }
}