choose-rand

A small crate for choosing random items from a set of weighed items.

Installation/Setup

To import the crate into your project, simply run cargo add choose-rand or open your Cargo.toml and add choose-rand = "<latest release>"

In any file that you want to use the crate, add use choose_rand::prelude::*; and use eq_float::F64; (the eq_float part is for when you need to impl Probable)

Examples

1. Enum

use choose_rand::prelude::*;
use eq_float::F64;

#[derive(Hash, Eq, PartialEq, Clone, Debug)]
enum Test {
    foo,
    bar,
    buz
}

impl Probable for Test {
    fn probability(&self) -> F64 {
        match self {
            Test::foo => F64(0.1),
            Test::bar => F64(0.2),
            Test::buz => F64(0.7)
        }
    }
}

fn main() {
    // all probabilities must add up to 1 or else it will (sometimes) fail.
    // it also works with BTreeSet
    let things = HashSet::from([
        Test::foo,
        Test::bar, 
        Test::buz
    ]);
    
    let chosen = choose_rand(&things).unwrap();

    println!("The chosen one is: {:#?}", chosen);
}

2. Struct

use choose_rand::prelude::*;
use eq_float::F64;

#[derive(Hash, Eq, PartialEq, Clone, Debug)]
struct Test(F64);

impl Probable for Test {
    fn probability(&self) -> F64 {
        self.0
    }
}

fn main() {
    // all probabilities must add up to 1 or else it will (sometimes) fail.
    // it also works with BTreeSet
    let things = HashSet::from([
        Test(F64(0.1)),
        Test(F64(0.2)),
        Test(F64(0.7))
    ]);

    let chosen = choose_rand(&things).unwrap();

    println!("The chosen one is: {:#?}", chosen);
}

License

This library is licensed under the MIT license.