Struct HashedPermutation

pub struct HashedPermutation {
    pub seed: u32,
    pub length: NonZeroU32,
}

The HashedPermutation struct stores the initial seed and length of the permutation vector. In other words, if you want to shuffle the numbers from 0..n, then length = n.

Because the shuffle is performed using bit arithmetic, the fields have to be 32 bit integers. Unfortunately, larger types are not supported at this time.

Fields

seed: u32

The random seed that dictates which permutation you want to use. The shuffle is deterministic, so using the same seed will yield the same permutation every time.

length: NonZeroU32

The upper bound on the range of numbers to shuffle (from 0..length). This value must be greater zero, otherwise undefined behavior may occur.

Implementations

impl HashedPermutation

pub fn new_with_seed(length: NonZeroU32, seed: u32) -> Self

Create a new instance of the hashed permutation given a length and seed

pub fn shuffle(&self, input: u32) -> PermutationResult<u32>

Shuffle or permute a particular value.

This method uses the technique described in Kensler’s paper to perform an in-place shuffle with no memory overhead.

Trait Implementations

impl Clone for HashedPermutation

fn clone(&self) -> HashedPermutation

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for HashedPermutation

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.