solidity/tools/yulPhaser/Population.h

88 lines
2.7 KiB
C++

/*
This file is part of solidity.
solidity is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
solidity is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with solidity. If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include <tools/yulPhaser/Chromosome.h>
#include <tools/yulPhaser/Program.h>
#include <tools/yulPhaser/SimulationRNG.h>
#include <optional>
#include <ostream>
#include <vector>
namespace solidity::phaser
{
/**
* Information describing the state of an individual member of the population during the course
* of the genetic algorithm.
*/
struct Individual
{
Chromosome chromosome;
std::optional<size_t> fitness = std::nullopt;
friend std::ostream& operator<<(std::ostream& _stream, Individual const& _individual);
};
/**
* Represents a changing set of individuals undergoing a genetic algorithm.
* Each round of the algorithm involves mutating existing individuals, evaluating their fitness
* and selecting the best ones for the next round.
*
* An individual is a sequence of optimiser steps represented by a @a Chromosome instance. The whole
* population is associated with a fixed Yul program. By applying the steps to the @a Program
* instance the class can compute fitness of the individual.
*/
class Population
{
public:
static constexpr size_t MaxChromosomeLength = 30;
explicit Population(Program _program, std::vector<Chromosome> const& _chromosomes = {});
static Population makeRandom(Program _program, size_t _size);
void run(std::optional<size_t> _numRounds, std::ostream& _outputStream);
std::vector<Individual> const& individuals() const { return m_individuals; }
static size_t randomChromosomeLength() { return SimulationRNG::binomialInt(MaxChromosomeLength, 0.5); }
static size_t measureFitness(Chromosome const& _chromosome, Program const& _program);
friend std::ostream& operator<<(std::ostream& _stream, Population const& _population);
private:
explicit Population(Program _program, std::vector<Individual> _individuals):
m_program{std::move(_program)},
m_individuals{std::move(_individuals)} {}
void doMutation();
void doEvaluation();
void doSelection();
static void randomizeWorstChromosomes(
std::vector<Individual>& _individuals,
size_t _count
);
Program m_program;
std::vector<Individual> m_individuals;
};
}