From bf8e11ed52587eaca15a6bdb22de9a6bfe0d3b20 Mon Sep 17 00:00:00 2001
From: Rutherther <rutherther@ditigal.xyz>
Date: Sat, 18 Oct 2025 10:46:59 +0200
Subject: [PATCH] refactor: properly handle errors in local_search

---
 env/Cargo.lock                   |  1 +
 env/Cargo.toml                   |  1 +
 env/src/binary_string.rs         |  7 ++++---
 env/src/evolutionary_strategy.rs |  6 +++---
 env/src/fitness/mod.rs           |  4 ++--
 env/src/local_search/mod.rs      | 20 +++++++++-----------
 6 files changed, 20 insertions(+), 19 deletions(-)

diff --git a/env/Cargo.lock b/env/Cargo.lock
index 5a70ec41086efe32dc03e1ebb39c28c6ce7d1cc8..a45fc5bf880a322d2ba752ea06e518564f64cfb1 100644
--- a/env/Cargo.lock
+++ b/env/Cargo.lock
@@ -208,6 +208,7 @@ dependencies = [
  "plotters",
  "rand",
  "rand_distr",
+ "thiserror",
 ]
 
 [[package]]
diff --git a/env/Cargo.toml b/env/Cargo.toml
index 00fc0305d2cdd8341ceabee40915fbd9d2ebc7c1..2fb77112c042379f14dda8a93fe30a318238cf08 100644
--- a/env/Cargo.toml
+++ b/env/Cargo.toml
@@ -8,3 +8,4 @@ nalgebra = "0.33.2"
 plotters = "0.3.7"
 rand = "0.9.2"
 rand_distr = "0.5.1"
+thiserror = "2.0.17"
diff --git a/env/src/binary_string.rs b/env/src/binary_string.rs
index f2b5cf4dac32613df413b4abd7b7ffe65283e71c..75b5ba9c46016a5811b29610a4ade2fd08f54799 100644
--- a/env/src/binary_string.rs
+++ b/env/src/binary_string.rs
@@ -1,6 +1,7 @@
-use std::str::FromStr;
+use std::{error::Error, str::FromStr};
 use nalgebra::{allocator::Allocator, Const, DefaultAllocator, Dim, DimName, Dynamic, OVector, SVector, U1};
 use rand::{Rng, RngCore};
+use thiserror::Error;
 
 #[derive(Debug, Clone, PartialEq)]
 pub struct Bounds {
@@ -30,10 +31,10 @@ pub struct BinaryString {
     pub vec: Vec<i8>
 }
 
-#[derive(Debug, Clone, PartialEq)]
+#[derive(Error, Debug, Clone, PartialEq)]
 pub enum BinaryStringConversionError {
+    #[error("The dimension of the bounds does not divide the length of the binary string.")]
     DimensionMismatch,
-    NoBounds
 }
 
 impl BinaryString {
diff --git a/env/src/evolutionary_strategy.rs b/env/src/evolutionary_strategy.rs
index da8805e62c43231f748c0cfe0d069430b245b4f2..d2758c5629c770822bdd0d2a5ff977f249ba38f4 100644
--- a/env/src/evolutionary_strategy.rs
+++ b/env/src/evolutionary_strategy.rs
@@ -1,12 +1,12 @@
-use std::convert::Infallible;
+use std::{convert::Infallible, error::Error};
 
 use nalgebra::SVector;
 use rand_distr::{Normal, NormalError};
 
-use crate::{local_search::{LocalSearchCandidate, LocalSearchStats}, perturbation::{BoundedPerturbation, PerturbationOperator, RandomDistributionPerturbation}};
+use crate::{local_search::LocalSearchStats, perturbation::{BoundedPerturbation, PerturbationOperator, RandomDistributionPerturbation}};
 
 pub trait EvolutionaryStrategy<TOut, TPerturbation: PerturbationOperator> {
-    type Err;
+    type Err: Error + 'static;
 
     fn step(&mut self,
             perturbation: &mut TPerturbation,
diff --git a/env/src/fitness/mod.rs b/env/src/fitness/mod.rs
index e24623ed647c54eeb1788cd4de0f639be404c909..0dcccaf665133d1b62c25a7eb3da71ea8df3ae0b 100644
--- a/env/src/fitness/mod.rs
+++ b/env/src/fitness/mod.rs
@@ -1,4 +1,4 @@
-use std::convert::Infallible;
+use std::{convert::Infallible, error::Error};
 
 use nalgebra::{allocator::Allocator, DefaultAllocator, Dim, OVector, SVector};
 
@@ -13,7 +13,7 @@ pub mod real;
 pub trait FitnessFunction {
     type In;
     type Out;
-    type Err;
+    type Err: Error + 'static;
 
     fn fit(self: &Self, inp: &Self::In) -> Result<Self::Out, Self::Err>;
 }
diff --git a/env/src/local_search/mod.rs b/env/src/local_search/mod.rs
index 53e5f4f23db7a360fe002f867ba0b421181bdac2..c3ca90ff25e2f6709386c6c0d31d32e0b52610ed 100644
--- a/env/src/local_search/mod.rs
+++ b/env/src/local_search/mod.rs
@@ -1,3 +1,4 @@
+use std::error::Error;
 use std::fmt::Debug;
 use crate::binary_string::{BinaryString, BinaryStringConversionError};
 use crate::evolutionary_strategy::{EvolutionaryStrategy, IdentityStrategy};
@@ -82,17 +83,17 @@ pub struct LocalSearchResult<TInput, TResult>
 }
 
 pub fn local_search_first_improving<
-        TInput, TResult, TErr, TFit, TTerminatingCondition, TPerturbationOperator, TBetterThanOperator>(
+        TInput, TResult, TFit, TTerminatingCondition, TPerturbationOperator, TBetterThanOperator>(
     fit: &TFit,
     terminating_condition: &mut TTerminatingCondition,
     perturbation_operator: &mut TPerturbationOperator,
     better_than_operator: &TBetterThanOperator,
     initial: &TInput
-) -> Result<LocalSearchResult<TInput, TResult>, TErr>
+) -> Result<LocalSearchResult<TInput, TResult>, Box<dyn Error>>
 where
     TResult: Clone,
     TInput: Clone,
-    TFit: FitnessFunction<In = TInput, Out = TResult, Err = TErr>,
+    TFit: FitnessFunction<In = TInput, Out = TResult>,
     TTerminatingCondition: TerminatingCondition<TInput, TResult>,
     TPerturbationOperator: PerturbationOperator<Chromosome = TInput>,
     TBetterThanOperator: BetterThanOperator<TResult>,
@@ -108,23 +109,22 @@ where
 }
 
 pub fn local_search_first_improving_evolving<
-        TInput, TResult, TErr, TFit, TTerminatingCondition, TPerturbationOperator, TBetterThanOperator, TEvolutionaryStrategy>(
+        TInput, TResult, TFit, TTerminatingCondition, TPerturbationOperator, TBetterThanOperator, TEvolutionaryStrategy>(
     fit: &TFit,
     terminating_condition: &mut TTerminatingCondition,
     perturbation_operator: &mut TPerturbationOperator,
     better_than_operator: &TBetterThanOperator,
     evolutionary_strategy: &mut TEvolutionaryStrategy,
     initial: &TInput
-) -> Result<LocalSearchResult<TInput, TResult>, TErr>
+) -> Result<LocalSearchResult<TInput, TResult>, Box<dyn Error>>
 where
     TResult: Clone,
     TInput: Clone,
-    TFit: FitnessFunction<In = TInput, Out = TResult, Err = TErr>,
+    TFit: FitnessFunction<In = TInput, Out = TResult>,
     TTerminatingCondition: TerminatingCondition<TInput, TResult>,
     TPerturbationOperator: PerturbationOperator<Chromosome = TInput>,
     TEvolutionaryStrategy: EvolutionaryStrategy<TResult, TPerturbationOperator>,
-    TBetterThanOperator: BetterThanOperator<TResult>,
-    <TEvolutionaryStrategy as EvolutionaryStrategy<TResult, TPerturbationOperator>>::Err: Debug
+    TBetterThanOperator: BetterThanOperator<TResult>
 {
     let mut best_candidate = LocalSearchCandidate {
         pos: initial.clone(),
@@ -157,9 +157,7 @@ where
         evolutionary_strategy.step(
             perturbation_operator,
             better,
-            &stats)
-        // TODO
-            .expect("Evolution failed.");
+            &stats)?;
 
         cycle += 1;
     }