partial_functional/monoid/
mod.rs

1mod last;
2mod first;
3mod sum;
4mod product;
5mod any;
6mod all;
7mod min;
8mod max;
9
10pub use self::{
11    last::Last,
12    first::First,
13    sum::Sum,
14    product::Product,
15    any::Any,
16    all::All,
17    min::Min,
18    max::Max,
19};
20
21use crate::semigroup::Semigroup;
22
23pub trait Monoid: Semigroup {
24    fn empty() -> Self;
25}
26
27impl<T: Semigroup + Default> Monoid for T {
28    fn empty() -> Self {
29        Default::default()
30    }
31}
32
33#[cfg(test)]
34mod tests {
35    use super::*;
36
37    use super::last::Last;
38    use super::sum::Sum;
39
40    #[test]
41    fn combine_with_into() {
42        let x = Last::empty()
43            .combine(53.into())
44            .combine(None.into())
45            .combine(42.into());
46
47        assert_eq!(x.0, Some(42));
48    }
49
50    #[test]
51    fn option_combine_macro() {
52        let sum: Option<Sum<i32>> = crate::combine!(
53            None,
54            Sum::from(10),
55            None,
56            Sum::from(5),
57            Sum::from(7),
58            None,
59            Sum::from(42),
60            None,
61        );
62
63        assert_eq!(sum.unwrap(), 64);
64    }
65
66    #[test]
67    fn combine_macro() {
68        let x = crate::combine! {
69            Last::from(53), None, 42, {let b = None; b},
70        };
71
72        assert_eq!(x.0, Some(42));
73    }
74
75    #[test]
76    fn last_to_option_conversion() {
77        let last = Last::from(42);
78        let res: Option<i32> = last.into();
79
80        assert_eq!(res, Some(42));
81    }
82}
partial_functional/monoid/mod.rs

partial_functional/monoid/
mod.rs
