Trait Alternative 

pub trait Alternative: Applicative + Plus { }

A type class combining Applicative and Plus.

Alternative has no members of its own; it specifies that the type constructor has both Applicative and Plus instances.

Laws

Alternative instances must satisfy the following laws:

• Distributivity: apply(alt(f, g), x) = alt(apply(f, x), apply(g, x)).
• Annihilation: apply(empty, f) = empty.

Examples

Alternative laws for Vec:

use fp_library::{
	brands::*,
	classes::*,
	functions::*,
};

// Annihilation: apply(empty, f) = empty
let f: Vec<i32> = vec![1, 2, 3];
let empty_fns: Vec<std::rc::Rc<dyn Fn(i32) -> i32>> = plus_empty::<VecBrand, _>();
let result = apply(empty_fns, f);
assert_eq!(result, plus_empty::<VecBrand, i32>());

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl<Brand> Alternative for Brand

where Brand: Applicative + Plus,

Blanket implementation of Alternative.

Type Parameters

• Brand: The brand type.