genx 0.4.0

An easy to use and modular genetic algorithms library.
Documentation 
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use std::mem::swap;

use rand::{Rng, SeedableRng, rngs::StdRng, seq::SliceRandom};

/**
## Description
Scramble mutation is a mutation only for vector encoded individuals.
Given the `individual` it randomly generates two indices and then
shuffles the values between those two indices.

_Note: The function can also take in an optional `seed` value of type `Option<u64>` for deterministic results._

## Example
```rust
  use genx::mutation::scramble_mutation;
  let mut individual = vec![false, true, false, false,
                            true, true, true, false, false, true, false,
                            false, true, false, false, true];
  let original_individual = individual.clone();
  scramble_mutation(&mut individual, Some(42));
  assert_ne!(original_individual, individual);
```
*/
pub fn scramble_mutation<T>(individual: &mut Vec<T>, seed: Option<u64>) {
  let mut prng = match seed {
    Some(val) => StdRng::seed_from_u64(val),
    None => StdRng::from_entropy()
  };

  let length_of_individual = individual.len();

  let mut idx1 = prng.gen_range(0..length_of_individual);
  let mut idx2 = prng.gen_range(0..length_of_individual);

  if idx2 < idx1 {
    swap(&mut idx1, &mut idx2);
  }

  let slice = &mut individual[idx1..=idx2];
  slice.shuffle(&mut prng);
}