From ad89b477c86cd4f9ac632260a87549a6b7f132c6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kamil=20=C5=9Aliwak?= <kamil.sliwak@codepoets.it>
Date: Wed, 11 Mar 2020 03:38:31 +0100
Subject: [PATCH] [yul-phaser] GeneticAlgorithms: Add methods for selecting a
 crossover operator

---
 tools/yulPhaser/GeneticAlgorithms.cpp | 39 +++++++++++++++++++++++++++
 tools/yulPhaser/GeneticAlgorithms.h   | 20 ++++++++++++++
 2 files changed, 59 insertions(+)

diff --git a/tools/yulPhaser/GeneticAlgorithms.cpp b/tools/yulPhaser/GeneticAlgorithms.cpp
index 701bdf28c..7dcc44ed4 100644
--- a/tools/yulPhaser/GeneticAlgorithms.cpp
+++ b/tools/yulPhaser/GeneticAlgorithms.cpp
@@ -21,8 +21,47 @@
 #include <tools/yulPhaser/PairSelections.h>
 
 using namespace std;
+using namespace solidity;
 using namespace solidity::phaser;
 
+function<Crossover> phaser::buildCrossoverOperator(
+	CrossoverChoice _choice,
+	optional<double> _uniformCrossoverSwapChance
+)
+{
+	switch (_choice)
+	{
+		case CrossoverChoice::SinglePoint:
+			return randomPointCrossover();
+		case CrossoverChoice::TwoPoint:
+			return randomTwoPointCrossover();
+		case CrossoverChoice::Uniform:
+			assert(_uniformCrossoverSwapChance.has_value());
+			return uniformCrossover(_uniformCrossoverSwapChance.value());
+		default:
+			assertThrow(false, solidity::util::Exception, "Invalid CrossoverChoice value.");
+	};
+}
+
+function<SymmetricCrossover> phaser::buildSymmetricCrossoverOperator(
+	CrossoverChoice _choice,
+	optional<double> _uniformCrossoverSwapChance
+)
+{
+	switch (_choice)
+	{
+		case CrossoverChoice::SinglePoint:
+			return symmetricRandomPointCrossover();
+		case CrossoverChoice::TwoPoint:
+			return symmetricRandomTwoPointCrossover();
+		case CrossoverChoice::Uniform:
+			assert(_uniformCrossoverSwapChance.has_value());
+			return symmetricUniformCrossover(_uniformCrossoverSwapChance.value());
+		default:
+			assertThrow(false, solidity::util::Exception, "Invalid CrossoverChoice value.");
+	};
+}
+
 Population RandomAlgorithm::runNextRound(Population _population)
 {
 	RangeSelection elite(0.0, m_options.elitePoolSize);
diff --git a/tools/yulPhaser/GeneticAlgorithms.h b/tools/yulPhaser/GeneticAlgorithms.h
index 0d1f0375f..22ab62c04 100644
--- a/tools/yulPhaser/GeneticAlgorithms.h
+++ b/tools/yulPhaser/GeneticAlgorithms.h
@@ -20,11 +20,31 @@
 
 #pragma once
 
+#include <tools/yulPhaser/Mutations.h>
 #include <tools/yulPhaser/Population.h>
 
+#include <optional>
+
 namespace solidity::phaser
 {
 
+enum class CrossoverChoice
+{
+	SinglePoint,
+	TwoPoint,
+	Uniform,
+};
+
+std::function<Crossover> buildCrossoverOperator(
+	CrossoverChoice _choice,
+	std::optional<double> _uniformCrossoverSwapChance
+);
+
+std::function<SymmetricCrossover> buildSymmetricCrossoverOperator(
+	CrossoverChoice _choice,
+	std::optional<double> _uniformCrossoverSwapChance
+);
+
 /**
  * Abstract base class for genetic algorithms.
  * The main feature is the @a runNextRound() method that executes one round of the algorithm,