Initial commit.

.gitignore

@@ -0,0 +1,3 @@
+/target/
+
+Cargo.lock

.gitlab-ci.yml

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+image: "rust:latest"
+
+variables:
+  CARGO_HOME: $CI_PROJECT_DIR/cargo
+
+test:cargo:
+  script:
+    - rustc --version && cargo --version
+    - time cargo test --verbose --jobs 1 --release
+
+  cache:
+    paths:
+      - target/
+      - cargo/

Cargo.toml

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+[package]
+name = "genetisk"
+version = "0.1.0"
+authors = ["logaritmisk <anders.e.olsson@gmail.com>"]
+
+[dependencies]
+rayon = "0.9"
+
+[[example]]
+name = "parabole"
+path = "examples/parabole.rs"
+
+[dev-dependencies]
+rand = "0.3"
+
+[profile.release]
+lto = true

examples/parabole.rs

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+extern crate rand;
+extern crate rayon;
+extern crate genetisk;
+
+use std::cmp::Ordering;
+
+
+use rand::distributions::{IndependentSample, Range};
+use rayon::prelude::*;
+
+use genetisk::{Individual, Wrapper, MaximizeSelector, MinimizeSelector, Select, Simulation};
+
+
+#[derive(Clone, Copy, Debug)]
+struct Fitness(f64);
+
+impl PartialEq for Fitness {
+    fn eq(&self, other: &Fitness) -> bool {
+        (self.0 - other.0).abs() < 0.0001
+    }
+}
+
+impl Eq for Fitness {}
+
+impl PartialOrd for Fitness {
+    fn partial_cmp(&self, other: &Fitness) -> Option<Ordering> {
+        self.0.partial_cmp(&other.0)
+    }
+}
+
+impl Ord for Fitness {
+    fn cmp(&self, other: &Fitness) -> Ordering {
+        self.0.partial_cmp(&other.0).unwrap_or(Ordering::Equal)
+    }
+}
+
+
+#[derive(Clone, Debug)]
+struct Parabole {
+    x: f64,
+}
+
+impl Individual for Parabole {
+    type Fitness = Fitness;
+
+    fn mate(&self, other: &Parabole) -> Parabole {
+        Parabole {
+            x: (self.x + other.x) / 2.0,
+        }
+    }
+
+    fn mutate(&mut self) {
+        let between = Range::new(-1.0, 1.0);
+
+        let mut rng = rand::thread_rng();
+        let offset = between.ind_sample(&mut rng);
+
+        self.x += offset;
+    }
+
+    fn fitness(&self) -> Self::Fitness {
+        Fitness(10.0 - ((self.x + 3.0) * (self.x + 3.0)))
+    }
+}
+
+
+fn main() {
+    let initial = (0..300)
+        .map(|i| Parabole { x: i as f64 })
+        .collect::<Vec<_>>();
+
+    let population_size = initial.len();
+
+    let mut simulation = Simulation::with_population(initial);
+
+    simulation.calculate();
+
+    for _ in 0..250_000 {
+        simulation.evolve(|parents, population| {
+            // Mate top 10 to get 5 children.
+            parents
+                .iter()
+                .enumerate()
+                .filter(|&(n, _)| n % 2 == 0)
+                .map(|(_, wrapper)| wrapper)
+                .take(5)
+                .zip(
+                    parents
+                        .iter()
+                        .enumerate()
+                        .filter(|&(n, _)| n % 2 == 1)
+                        .map(|(_, wrapper)| wrapper)
+                        .take(5),
+                )
+                .map(|(a, b)| a.individual.mate(&b.individual))
+                .map(|individual| Wrapper {
+                    individual: individual,
+                    fitness: None,
+                })
+                .for_each(|wrapper| {
+                    population.push(wrapper);
+                });
+
+            // Mutate all to get new children.
+            parents
+                .par_iter()
+                .map(|wrapper| wrapper.individual.clone())
+                .map(|mut individual| {
+                    individual.mutate();
+
+                    Wrapper {
+                        individual: individual,
+                        fitness: None,
+                    }
+                })
+                .collect_into(population);
+
+            // Add all parents again.
+            population.extend(parents.iter().cloned());
+        });
+
+        simulation.population.truncate(population_size);
+    }
+
+    println!(
+        "{:#?}",
+        simulation.population
+            .iter()
+            .take(10)
+            .map(|individual| &individual.individual)
+            .collect::<Vec<_>>()
+    );
+    println!();
+}

src/lib.rs

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+extern crate rayon;
+
+
+use rayon::prelude::*;
+
+
+pub trait Individual: Send {
+    type Fitness: Send + Ord;
+
+    fn fitness(&self) -> Self::Fitness;
+
+    fn mate(&self, other: &Self) -> Self;
+    fn mutate(&mut self);
+}
+
+
+pub trait Select<T>: Send
+where
+    T: Individual
+{
+    fn select(&self, population: Vec<Wrapper<T>>) -> Vec<Wrapper<T>>;
+}
+
+
+pub struct MaximizeSelector {
+    count: usize,
+}
+
+impl MaximizeSelector {
+    pub fn new(count: usize) -> Self {
+        MaximizeSelector {
+            count: count,
+        }
+    }
+}
+
+impl<T> Select<T> for MaximizeSelector
+where
+    T: Individual
+{
+    fn select(&self, mut population: Vec<Wrapper<T>>) -> Vec<Wrapper<T>> {
+        population.par_sort_unstable_by(|a, b| b.fitness.cmp(&a.fitness));
+
+        population.into_iter().take(self.count).collect()
+    }
+}
+
+
+pub struct MinimizeSelector {
+    count: usize,
+}
+
+impl MinimizeSelector {
+    pub fn new(count: usize) -> Self {
+        MinimizeSelector {
+            count: count,
+        }
+    }
+}
+
+impl<T> Select<T> for MinimizeSelector
+where
+    T: Individual
+{
+    fn select(&self, mut population: Vec<Wrapper<T>>) -> Vec<Wrapper<T>> {
+        population.par_sort_unstable_by(|a, b| a.fitness.cmp(&b.fitness));
+
+        population.into_iter().take(self.count).collect()
+    }
+}
+
+
+#[derive(Clone)]
+pub struct Wrapper<T>
+where
+    T: Individual,
+{
+    pub individual: T,
+    pub fitness: Option<T::Fitness>,
+}
+
+
+pub struct Simulation<T>
+where
+    T: Individual,
+{
+    pub population: Vec<Wrapper<T>>,
+}
+
+impl<T> Simulation<T>
+where
+    T: Individual,
+{
+    pub fn with_population(initial: Vec<T>) -> Self {
+        let mut population = Vec::with_capacity(initial.len() * 2);
+
+        initial
+            .into_par_iter()
+            .map(|individual| Wrapper {
+                individual: individual,
+                fitness: None,
+            })
+            .collect_into(&mut population);
+
+        Simulation {
+            population: population,
+        }
+    }
+
+    pub fn calculate(&mut self) {
+        self.population.par_iter_mut()
+            .filter(|wrapper| wrapper.fitness.is_none())
+            .for_each(|wrapper| wrapper.fitness = Some(wrapper.individual.fitness()));
+
+        self.population.par_sort_unstable_by(|a, b| b.fitness.cmp(&a.fitness));
+    }
+
+    pub fn evolve<F>(&mut self, func: F)
+    where
+        F: Fn(&[Wrapper<T>], &mut Vec<Wrapper<T>>)
+    {
+        let mut population = Vec::with_capacity(self.population.len());
+
+        func(&self.population, &mut population);
+
+        self.population = population;
+
+        self.calculate();
+    }
+}