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
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
|
//! FIXME: write short doc here
#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub enum Either<A, B> {
A(A),
B(B),
}
impl<A, B> Either<A, B> {
pub fn either<R, F1, F2>(self, f1: F1, f2: F2) -> R
where
F1: FnOnce(A) -> R,
F2: FnOnce(B) -> R,
{
match self {
Either::A(a) => f1(a),
Either::B(b) => f2(b),
}
}
pub fn map<U, V, F1, F2>(self, f1: F1, f2: F2) -> Either<U, V>
where
F1: FnOnce(A) -> U,
F2: FnOnce(B) -> V,
{
match self {
Either::A(a) => Either::A(f1(a)),
Either::B(b) => Either::B(f2(b)),
}
}
pub fn map_a<U, F>(self, f: F) -> Either<U, B>
where
F: FnOnce(A) -> U,
{
self.map(f, |it| it)
}
pub fn a(self) -> Option<A> {
match self {
Either::A(it) => Some(it),
Either::B(_) => None,
}
}
pub fn b(self) -> Option<B> {
match self {
Either::A(_) => None,
Either::B(it) => Some(it),
}
}
pub fn as_ref(&self) -> Either<&A, &B> {
match self {
Either::A(it) => Either::A(it),
Either::B(it) => Either::B(it),
}
}
}
|
