1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25

use crate::hkt::HKT;

pub trait Chain<B>: HKT<B> {
    fn chain<F>(self, f: F) -> <Self as HKT<B>>::Target
    where
        F: FnOnce(<Self as HKT<B>>::Current) -> <Self as HKT<B>>::Target;
}

impl<A, B> Chain<B> for Option<A> {
    fn chain<F>(self, f: F) -> Self::Target
    where
        F: FnOnce(A) -> <Self as HKT<B>>::Target,
    {
        self.and_then(f)
    }
}

impl<A, B, E> Chain<B> for Result<A, E> {
    fn chain<F>(self, f: F) -> Self::Target
    where
        F: FnOnce(A) -> <Self as HKT<B>>::Target,
    {
        self.and_then(f)
    }
}