Trait Commutative

Source

pub trait Commutative: Semigroup { }

Expand description

Commutative represents a binary operation that satisfies the following property

Commutativity: op(a, b) = op(b, a)

The semigroup set that satisfies the commutativity property is often called commutative semigroup.

And the monoid set that satisfies the commutativity property is often called commutative monoid.

§Deriving

Commutative can be derived like Semigroup, use commutative attribute.

use semigroup::Semigroup;
#[derive(Debug, Clone, PartialEq, Default, Semigroup)]
#[semigroup(commutative)]
pub struct ExampleStruct {
    #[semigroup(with = "semigroup::op::Sum")]
    pub sum: u32,
    #[semigroup(with = "semigroup::op::Min")]
    pub min: u32,
}

let a = ExampleStruct { sum: 1, min: 1 };
let b = ExampleStruct { sum: 10, min: 10 };
let c = ExampleStruct { sum: 100, min: 100 };

// #[test]
semigroup::assert_commutative!(&a, &b, &c);
assert_eq!(a.semigroup(b).semigroup(c), ExampleStruct { sum: 111, min: 1 });