From d3530ea75d762038911abaf298a4b44bc80c534f Mon Sep 17 00:00:00 2001
From: Manlio Morini <morinim@gmail.com>
Date: Wed, 1 May 2024 19:18:05 +0200
Subject: [PATCH] feat: add support for classification to `src::search`

Issue #11
---
 src/kernel/gp/src/evaluator.h   |  4 ++--
 src/kernel/gp/src/evaluator.tcc | 20 +++++++++++++++-----
 src/kernel/gp/src/search.h      |  2 ++
 src/kernel/gp/src/search.tcc    |  4 ++--
 4 files changed, 21 insertions(+), 9 deletions(-)

diff --git a/src/kernel/gp/src/evaluator.h b/src/kernel/gp/src/evaluator.h
index dcdcbf7..536692d 100644
--- a/src/kernel/gp/src/evaluator.h
+++ b/src/kernel/gp/src/evaluator.h
@@ -258,8 +258,8 @@ class gaussian_evaluator : public evaluator<dataframe>
 public:
   explicit gaussian_evaluator(dataframe &);
 
-  [[nodiscard]] double operator()(const P &) override;
-  std::unique_ptr<basic_oracle> oracle(const P &) const;
+  [[nodiscard]] double operator()(const P &) const;
+  [[nodiscard]] std::unique_ptr<basic_oracle> oracle(const P &) const;
 };
 
 #include "kernel/gp/src/evaluator.tcc"
diff --git a/src/kernel/gp/src/evaluator.tcc b/src/kernel/gp/src/evaluator.tcc
index c234525..418a677 100644
--- a/src/kernel/gp/src/evaluator.tcc
+++ b/src/kernel/gp/src/evaluator.tcc
@@ -108,10 +108,9 @@ auto sum_of_errors_evaluator<P, ERRF, DAT>::fast(const P &prg) const
 }
 
 ///
-/// \param[in] prg program(individual/team) to be transformed in a lambda
-///                function
-/// \return        the lambda function associated with `prg` (`nullptr` in case
-///                of errors).
+/// \param[in] prg program (individual/team) to be transformed in an oracle
+/// \return        the oracle associated with `prg` (`nullptr` in case of
+///                errors).
 ///
 template<IndividualOrTeam P, template<class> class ERRF, class DAT>
 requires ErrorFunction<ERRF<P>, DAT>
@@ -259,7 +258,7 @@ gaussian_evaluator<P>::gaussian_evaluator(dataframe &d) : evaluator(d)
 /// \return        the fitness (greater is better, max is `0`)
 ///
 template<IndividualOrTeam P>
-double gaussian_evaluator<P>::operator()(const P &prg)
+double gaussian_evaluator<P>::operator()(const P &prg) const
 {
   Expects(this->dat_->classes() >= 2);
   basic_gaussian_oracle<P, false, false> oracle(prg, *this->dat_);
@@ -287,4 +286,15 @@ double gaussian_evaluator<P>::operator()(const P &prg)
   return d;
 }
 
+///
+/// \param[in] prg program (individual/team) to be transformed in an oracle
+/// \return        the oracle associated with `prg` (`nullptr` in case of
+///                errors).
+///
+template<IndividualOrTeam P>
+std::unique_ptr<basic_oracle> gaussian_evaluator<P>::oracle(const P &prg) const
+{
+  return std::make_unique<gaussian_oracle<P>>(prg, *this->dat_);
+}
+
 #endif  // include guard
diff --git a/src/kernel/gp/src/search.h b/src/kernel/gp/src/search.h
index 75b9b4b..ab21399 100644
--- a/src/kernel/gp/src/search.h
+++ b/src/kernel/gp/src/search.h
@@ -72,9 +72,11 @@ class search
 public:
   using after_generation_callback_t =
     ultra::after_generation_callback_t<P, double>;
+
   using individual_t = P;
   using fitness_t = double;
 
+  using class_evaluator_t = gaussian_evaluator<P>;
   using reg_evaluator_t = rmae_evaluator<P>;
 
   search(problem &p, metric_flags m = metric_flags::nothing);
diff --git a/src/kernel/gp/src/search.tcc b/src/kernel/gp/src/search.tcc
index e57b536..f0df144 100644
--- a/src/kernel/gp/src/search.tcc
+++ b/src/kernel/gp/src/search.tcc
@@ -366,7 +366,7 @@ search_stats<P, typename search<P>::fitness_t> search<P>::run(
   });
 
   if (prob_.classification())
-    return {};
+    return search_scheme.template operator()<class_evaluator_t>();
   else
     return search_scheme.template operator()<reg_evaluator_t>();
 }
@@ -375,7 +375,7 @@ template<IndividualOrTeam P>
 std::unique_ptr<basic_oracle> search<P>::oracle(const P &prg) const
 {
   if (prob_.classification())
-    return nullptr;
+    return class_evaluator_t(prob_.data()).oracle(prg);
   else
     return reg_evaluator_t(prob_.data()).oracle(prg);
 }