blt-gp/include/blt/gp/program.h

140 lines
5.0 KiB
C++

#pragma once
/*
* Copyright (C) 2024 Brett Terpstra
*
* This program 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.
*
* This program 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 this program. If not, see <https://www.gnu.org/licenses/>.
*/
#ifndef BLT_GP_PROGRAM_H
#define BLT_GP_PROGRAM_H
#include <cstddef>
#include <functional>
#include <type_traits>
#include <string_view>
#include <string>
#include <utility>
#include <iostream>
#include <random>
#include <blt/std/ranges.h>
#include <blt/std/hashmap.h>
#include <blt/std/types.h>
#include <blt/std/utility.h>
#include <blt/std/memory.h>
#include <blt/gp/fwdecl.h>
#include <blt/gp/typesystem.h>
#include <blt/gp/operations.h>
#include <blt/gp/tree.h>
#include <blt/gp/stack.h>
namespace blt::gp
{
static constexpr blt::size_t NONE_T = 0x0;
static constexpr blt::size_t STATIC_T = 0x1;
static constexpr blt::size_t TERMINAL_T = 0x2;
class gp_program
{
public:
/**
* Note about context size: This is required as context is passed to every operator in the GP tree, this context will be provided by your
* call to one of the evaluator functions. This was the nicest way to provide this as C++ lacks reflection
*
* @param system type system to use in tree generation
* @param engine random engine to use throughout the program. TODO replace this with something better
* @param context_size number of arguments which are always present as "context" to the GP system / operators
*/
explicit gp_program(type_system& system, std::mt19937_64 engine):
system(system), engine(engine)
{}
void generate_tree();
[[nodiscard]] inline std::mt19937_64& get_random()
{
return engine;
}
[[nodiscard]] inline type_system& get_typesystem()
{
return system;
}
inline operator_id select_terminal(type_id id)
{
std::uniform_int_distribution<blt::size_t> dist(0, terminals[id].size() - 1);
return terminals[id][dist(engine)];
}
inline operator_id select_non_terminal(type_id id)
{
std::uniform_int_distribution<blt::size_t> dist(0, non_terminals[id].size() - 1);
return non_terminals[id][dist(engine)];
}
inline std::vector<type>& get_argument_types(operator_id id)
{
return argument_types[id];
}
inline std::vector<operator_id>& get_type_terminals(type_id id)
{
return terminals[id];
}
inline std::vector<operator_id>& get_type_non_terminals(type_id id)
{
return non_terminals[id];
}
inline bool is_static(operator_id id)
{
return static_types.contains(static_cast<blt::size_t>(id));
}
template<typename Return, typename... Args>
void add_operator(const operation_t<Return(Args...)>& op, bool is_static = false)
{
auto return_type_id = system.get_type<Return>().id();
auto operator_id = blt::gp::operator_id(operators.size());
auto& operator_list = op.get_argc() == 0 ? terminals : non_terminals;
operator_list[return_type_id].push_back(operator_id);
(argument_types[operator_id].push_back(system.get_type<Args>()), ...);
operators.push_back(op.make_callable());
if (is_static)
static_types.insert(operator_id);
}
private:
type_system& system;
blt::gp::stack_allocator alloc;
std::mt19937_64 engine;
// indexed from return TYPE ID, returns index of operator
blt::expanding_buffer<std::vector<operator_id>> terminals;
blt::expanding_buffer<std::vector<operator_id>> non_terminals;
// indexed from OPERATOR ID (operator number)
blt::expanding_buffer<std::vector<type>> argument_types;
blt::hashset_t<operator_id> static_types;
std::vector<std::function<void(stack_allocator&)>> operators;
};
}
#endif //BLT_GP_PROGRAM_H