#rng

choose-rand

A small crate for choosing random items from a set of weighted items

2 unstable releases

0.2.0 Sep 13, 2023
0.1.0 Mar 29, 2023

#48 in #rng

MIT license

11KB
167 lines

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

In any file that you want to use the crate, add use choose_rand::prelude::*;.

Examples

use choose_rand::prelude::*;
 
 #[derive(Debug, Clone)]
 struct Foo {
     prob: f32,
 }
 
 impl Probable for Foo {
     fn probability(&self) -> f32 {
         self.prob
     }
 }
 
 fn main() -> Result<()> {
     let v: Vec<_> = choose_rand::helper::refcellify(
         vec![Foo { prob: 0.25 }, Foo { prob: 0.5 }, Foo { prob: 0.1 }, Foo { prob: 0.05 }]
     ).collect();
 
     let mut rng = rand::thread_rng();    
     dbg!(v.choose_rand(&mut rng));
 
     Ok(())
 }

with features = ["eq_float"] for sets:

use choose_rand::prelude::*;
use eq_float::F32;
use std::collections::HashSet;

#[derive(Clone, Debug, Hash)]
struct Foo {
    prob: F32,
}

impl Foo {
    fn new(prob: f32) -> Self {
        Self { prob: F32(prob) }
    }
}

impl Probable for Foo {
    fn probablity(&self) -> F32 {
        self.prob
    }
}

fn main() -> Result<()> {
     let v: HashSet<_> = choose_rand::helper::refcellify(
         vec![Foo::new(0.25), Foo::new(0.5), Foo::new(0.1), Foo::new(0.05)]
     ).collect();
 
     let mut rng = rand::thread_rng();    
     dbg!(v.choose_rand(&mut rng));
 
     Ok(())
 }

License

This library is licensed under the MIT license.

Dependencies

~0.6–1.3MB
~28K SLoC