From 03a0e7a6502a93d9b582b2d04f65bff49a1a885b Mon Sep 17 00:00:00 2001
From: Rutherther <rutherther@ditigal.xyz>
Date: Sun, 30 Nov 2025 16:04:15 +0100
Subject: [PATCH] feat: Add BlendCrossover for reals

---
 codes/eoa_lib/src/crossover.rs | 62 ++++++++++++++++++++++++++++++++++
 1 file changed, 62 insertions(+)

diff --git a/codes/eoa_lib/src/crossover.rs b/codes/eoa_lib/src/crossover.rs
index b195352f922063b8bd1453afcdbea0628a08036a..59d7cf0fd8b7489d019a157939b3a6480ba11ec5 100644
--- a/codes/eoa_lib/src/crossover.rs
+++ b/codes/eoa_lib/src/crossover.rs
@@ -393,3 +393,65 @@ where
         Population::from_vec(offsprings)
     }
 }
+
+
+pub struct BlendCrossover<D: Dim, TOutput> {
+    alpha: f64,
+    _phantom1: PhantomData<D>,
+    _phantom2: PhantomData<TOutput>,
+}
+
+impl<D: Dim, TOutput> BlendCrossover<D, TOutput> {
+    pub fn new(alpha: f64) -> Self {
+        BlendCrossover {
+            alpha,
+            _phantom1: PhantomData,
+            _phantom2: PhantomData,
+        }
+    }
+}
+
+impl<D, TOutput> Crossover<2> for BlendCrossover<D, TOutput>
+where
+    D: Dim,
+    DefaultAllocator: Allocator<D>
+{
+    type Chromosome = OVector<f64, D>;
+    type Out = TOutput;
+
+    fn crossover(
+        &self,
+        population: &EvaluatedPopulation<Self::Chromosome, Self::Out>,
+        pairs: impl Iterator<Item = ParentPairing<2>>,
+        rng: &mut dyn RngCore
+    ) -> Population<Self::Chromosome> {
+        let mut offsprings = Vec::new();
+
+        for pair in pairs {
+            let (
+                parent1,
+                parent2
+            ) = (&population.population[pair.x], &population.population[pair.y]);
+
+            let (
+                chromosome1,
+                chromosome2
+            ) = (&parent1.chromosome, &parent2.chromosome);
+
+            offsprings.push(
+                chromosome1.zip_map(
+                    &chromosome2,
+                    |first, second| {
+                        let min = first.min(second);
+                        let max = first.max(second);
+
+                        let interval = (min - self.alpha * (max - min))..=(max + self.alpha * (max - min));
+
+                        rng.random_range(interval)
+                    }
+                ));
+        }
+
+        Population::from_vec(offsprings)
+    }
+}