use core::num::NonZeroUsize;
use rand::Rng;
use crate::gene::Gene;
use crate::genotype::Genotype;
use crate::random::Random;
use super::Mutation;
#[derive(Copy, Clone, Debug)]
#[allow(clippy::exhaustive_structs)]
pub struct Add {
pub chance: f64,
pub max_genes: Option<NonZeroUsize>,
}
impl<G, RNG> Mutation<Vec<G>, RNG> for Add
where
G: Gene + Random,
RNG: Rng,
{
fn mutate(&self, genotype: &mut Vec<G>, rng: &mut RNG) {
assert!(
self.chance >= 0.0_f64,
"chance of mutation has to be above or equal 0.0, but is {}",
self.chance
);
assert!(
self.chance <= 1.0_f64,
"chance of mutation has to be below or equal 1.0, but is {}",
self.chance
);
if let Some(max_genes) = self.max_genes {
if genotype.len() >= max_genes.get() {
return;
}
}
if rng.gen_bool(self.chance) {
let random_gene = G::random(rng);
let position_for_new_gene = rng.gen_range(0..=genotype.len());
genotype.insert(position_for_new_gene, random_gene);
}
}
}
impl<RNG> Mutation<String, RNG> for Add
where
RNG: Rng,
{
fn mutate(&self, genotype: &mut String, rng: &mut RNG) {
assert!(
self.chance >= 0.0_f64,
"chance of mutation has to be above or equal 0.0, but is {}",
self.chance
);
assert!(
self.chance <= 1.0_f64,
"chance of mutation has to be below or equal 1.0, but is {}",
self.chance
);
if let Some(max_genes) = self.max_genes {
if genotype.len() >= max_genes.get() {
return;
}
}
if rng.gen_bool(self.chance) {
let random_gene = <String as Genotype>::Gene::random(rng);
let mut chars = genotype.chars().collect::<Vec<_>>();
let position_for_new_gene = rng.gen_range(0..=chars.len());
chars.insert(position_for_new_gene, random_gene);
*genotype = chars.iter().collect::<String>();
}
}
}
#[cfg(test)]
mod tests {
use rand::rngs::SmallRng;
use rand::SeedableRng;
use super::{Add, Mutation};
#[test]
fn vector() {
let mutation = Add {
chance: 1.0_f64,
max_genes: None,
};
let mut rng = SmallRng::seed_from_u64(0);
let mut array = vec![0, 1, 2, 3, 4];
mutation.mutate(&mut array, &mut rng);
assert_eq!(array, [0, 1, 1_921_246_409, 2, 3, 4]);
}
#[test]
fn vector_max_genes() {
let mutation = Add {
chance: 1.0_f64,
max_genes: Some(5.try_into().unwrap()),
};
let mut rng = SmallRng::seed_from_u64(0);
let mut array = vec![0, 1, 2, 3, 4];
mutation.mutate(&mut array, &mut rng);
assert_eq!(array, [0, 1, 2, 3, 4]);
}
#[test]
fn string() {
let mutation = Add {
chance: 1.0_f64,
max_genes: None,
};
let mut rng = SmallRng::seed_from_u64(0);
let mut string = String::from("test");
mutation.mutate(&mut string, &mut rng);
assert_eq!(string, "te\u{79f2e}st");
}
}