Crate weighted_list 

Data structures for weighted randomisation.

This crate provides the WeightedList<V,W> struct, storing WeightedItems with a value and weight. When picking items randomly, those with a higher weight are more likely to be chosen.

Example

use weighted_list::*;
 
let wl = WeightedList::<String, u8>::from([
    (2, "sup".to_string()),
    (3, "nova".to_string()),
    (5, "shard".to_string()),
]);
 
for item in &wl {
    println!("{} has weight {}", item.value, item.weight);
}
 
if let Some(result) = wl.select_random_value(&mut rand::rng()) {
    println!("{result}");
}

Why might you need this?

• Weighted randomisation for a reward system
• Item stacking for an inventory system
• Statistical sampling

For more detailed guidance on how to use the struct, see WeightedList.

Macros

wit

Construct a WeightedItem from a (weight, value) pair.

wlist

Construct a WeightedList from the provided (weight, value) pairs.

Structs

NumCastError

An error returned when failing to cast one numeric type to another, which may be required for certain WeightedList operations.

WeightedItem

An item in a WeightedList, with a value of type V and a weight of numerical type W.

WeightedList

A homogeneous list of weighted items with values of type V and weights of numerical type W.

Traits

Weight

Any numerical type, such as u32, usize, f64. The type W of item weights in a WeightedList<V,W> must implement this trait.

Type Aliases

WItem

A shorthand for WeightedItem.

WList

A shorthand for WeightedList.