Hookup before and after hooks in Select, Crossover and Mutate Wrappers

Author: basvanwesting

CHANGELOG.md

@@ -7,15 +7,18 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## [0.26.0] - 2025-11-24
 
 ### Added
-* Add multiple extension points to the `Evolve` flow
-  * `after_selection_complete()` - called after selection completes
-  * `after_crossover_complete()` - called after crossover completes
-  * `after_mutation_complete()` - called after mutation completes
-  * `after_generation_complete()` - called at end of generation
-* Add reporter hooks `on_crossover_complete()` and `on_mutation_complete()`
-  * Provides observation points matching the new extension hooks
+* Add multiple extension points to the `Evolve` flow in the `Extension` type
+  * `after_selection_complete()`
+  * `after_crossover_complete()`
+  * `after_mutation_complete()`
+  * `after_generation_complete()`
+* Add symmetrical reporter hooks, called before the extension hooks
+  * `on_selection_complete()` (existing)
+  * `on_crossover_complete()`
+  * `on_mutation_complete()`
+  * `on_generation_complete()` (existing)
 * Add `before()` and `after()` hooks to `Select`, `Crossover`, and `Mutate` traits
-  * Allows customization of population lifecycle operations
+  * Allows full customization of population lifecycle operations in Evolve
   * Default implementations handle age filtering and cardinality updates
 
 ### Changed

src/crossover/wrapper.rs

@@ -26,6 +26,18 @@ pub enum Wrapper<G: EvolveGenotype> {
 impl<G: EvolveGenotype> Crossover for Wrapper<G> {
     type Genotype = G;
 
+    fn before(&mut self, genotype: &G, state: &mut EvolveState<G>, config: &EvolveConfig) {
+        match self {
+            Wrapper::Clone(crossover) => crossover.before(genotype, state, config),
+            Wrapper::MultiGene(crossover) => crossover.before(genotype, state, config),
+            Wrapper::MultiPoint(crossover) => crossover.before(genotype, state, config),
+            Wrapper::Rejuvenate(crossover) => crossover.before(genotype, state, config),
+            Wrapper::SingleGene(crossover) => crossover.before(genotype, state, config),
+            Wrapper::SinglePoint(crossover) => crossover.before(genotype, state, config),
+            Wrapper::Uniform(crossover) => crossover.before(genotype, state, config),
+        }
+    }
+
     fn call<R: Rng, SR: StrategyReporter<Genotype = G>>(
         &mut self,
         genotype: &G,
@@ -53,6 +65,18 @@ impl<G: EvolveGenotype> Crossover for Wrapper<G> {
         }
     }
 
+    fn after(&mut self, genotype: &G, state: &mut EvolveState<G>, config: &EvolveConfig) {
+        match self {
+            Wrapper::Clone(crossover) => crossover.after(genotype, state, config),
+            Wrapper::MultiGene(crossover) => crossover.after(genotype, state, config),
+            Wrapper::MultiPoint(crossover) => crossover.after(genotype, state, config),
+            Wrapper::Rejuvenate(crossover) => crossover.after(genotype, state, config),
+            Wrapper::SingleGene(crossover) => crossover.after(genotype, state, config),
+            Wrapper::SinglePoint(crossover) => crossover.after(genotype, state, config),
+            Wrapper::Uniform(crossover) => crossover.after(genotype, state, config),
+        }
+    }
+
     /// to guard against invalid Crossover strategies which break the internal consistency
     /// of the genes, unique genotypes can't simply exchange genes without gene duplication issues
     fn require_crossover_indexes(&self) -> bool {

src/mutate/wrapper.rs

@@ -22,6 +22,16 @@ pub enum Wrapper<G: EvolveGenotype> {
 impl<G: EvolveGenotype> Mutate for Wrapper<G> {
     type Genotype = G;
 
+    fn before(&mut self, genotype: &G, state: &mut EvolveState<G>, config: &EvolveConfig) {
+        match self {
+            Wrapper::MultiGene(mutate) => mutate.before(genotype, state, config),
+            Wrapper::MultiGeneDynamic(mutate) => mutate.before(genotype, state, config),
+            Wrapper::MultiGeneRange(mutate) => mutate.before(genotype, state, config),
+            Wrapper::SingleGene(mutate) => mutate.before(genotype, state, config),
+            Wrapper::SingleGeneDynamic(mutate) => mutate.before(genotype, state, config),
+        }
+    }
+
     fn call<R: Rng, SR: StrategyReporter<Genotype = G>>(
         &mut self,
         genotype: &G,
@@ -42,6 +52,16 @@ impl<G: EvolveGenotype> Mutate for Wrapper<G> {
             }
         }
     }
+
+    fn after(&mut self, genotype: &G, state: &mut EvolveState<G>, config: &EvolveConfig) {
+        match self {
+            Wrapper::MultiGene(mutate) => mutate.after(genotype, state, config),
+            Wrapper::MultiGeneDynamic(mutate) => mutate.after(genotype, state, config),
+            Wrapper::MultiGeneRange(mutate) => mutate.after(genotype, state, config),
+            Wrapper::SingleGene(mutate) => mutate.after(genotype, state, config),
+            Wrapper::SingleGeneDynamic(mutate) => mutate.after(genotype, state, config),
+        }
+    }
 }
 
 impl<G: EvolveGenotype> From<MutateSingleGene<G>> for Wrapper<G> {

src/select/wrapper.rs

@@ -18,6 +18,13 @@ pub enum Wrapper<G: EvolveGenotype> {
 impl<G: EvolveGenotype> Select for Wrapper<G> {
     type Genotype = G;
 
+    fn before(&mut self, genotype: &G, state: &mut EvolveState<G>, config: &EvolveConfig) {
+        match self {
+            Wrapper::Elite(select) => select.before(genotype, state, config),
+            Wrapper::Tournament(select) => select.before(genotype, state, config),
+        }
+    }
+
     fn call<R: Rng, SR: StrategyReporter<Genotype = G>>(
         &mut self,
         genotype: &G,
@@ -32,6 +39,13 @@ impl<G: EvolveGenotype> Select for Wrapper<G> {
         }
     }
 
+    fn after(&mut self, genotype: &G, state: &mut EvolveState<G>, config: &EvolveConfig) {
+        match self {
+            Wrapper::Elite(select) => select.after(genotype, state, config),
+            Wrapper::Tournament(select) => select.after(genotype, state, config),
+        }
+    }
+
     fn extract_elite_chromosomes(
         &self,
         state: &mut EvolveState<G>,