#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 . */ #ifndef BLT_GP_PROGRAM_H #define BLT_GP_PROGRAM_H #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include namespace blt::gp { struct argc_t { blt::u32 argc = 0; blt::u32 argc_context = 0; [[nodiscard]] bool is_terminal() const { return argc == 0; } }; struct operator_info { // types of the arguments std::vector argument_types; // return type of this operator type_id return_type; // number of arguments for this operator argc_t argc; // function to call this operator detail::callable_t function; // function used to transfer values between stacks detail::transfer_t transfer; }; struct operator_storage { // indexed from return TYPE ID, returns index of operator blt::expanding_buffer> terminals; blt::expanding_buffer> non_terminals; blt::expanding_buffer>> operators_ordered_terminals; // indexed from OPERATOR ID (operator number) blt::hashset_t static_types; std::vector operators; std::vector print_funcs; std::vector> names; }; template class operator_builder { friend class gp_program; friend class blt::gp::detail::operator_storage_test; public: explicit operator_builder(type_provider& system): system(system) {} template operator_builder& add_operator(const operation_t& op, bool is_static = false) { auto return_type_id = system.get_type().id(); auto operator_id = blt::gp::operator_id(storage.operators.size()); auto& operator_list = op.get_argc() == 0 ? storage.terminals : storage.non_terminals; operator_list[return_type_id].push_back(operator_id); operator_info info; if constexpr (sizeof...(Args) > 0) { (add_non_context_argument(info.argument_types), ...); } info.argc.argc_context = info.argc.argc = sizeof...(Args); info.return_type = system.get_type().id(); ((std::is_same_v, Context> ? info.argc.argc -= 1 : (blt::size_t) nullptr), ...); BLT_ASSERT(info.argc.argc_context - info.argc.argc <= 1 && "Cannot pass multiple context as arguments!"); info.function = op.template make_callable(); info.transfer = [](std::optional> to, stack_allocator& from) { #if BLT_DEBUG_LEVEL >= 3 auto value = from.pop(); //BLT_TRACE_STREAM << value << "\n"; if (to){ to->get().push(value); } #else if (to) { to->get().push(from.pop()); } else { from.pop(); } #endif }; storage.operators.push_back(info); storage.print_funcs.push_back([](std::ostream& out, stack_allocator& stack) { out << stack.pop(); }); storage.names.push_back(op.get_name()); if (is_static) storage.static_types.insert(operator_id); return *this; } operator_storage&& build() { blt::hashset_t has_terminals; for (const auto& v : blt::enumerate(storage.terminals)) { if (!v.second.empty()) has_terminals.insert(v.first); } for (const auto& op_r : blt::enumerate(storage.non_terminals)) { if (op_r.second.empty()) continue; auto return_type = op_r.first; std::vector> ordered_terminals; for (const auto& op : op_r.second) { // count number of terminals blt::size_t terminals = 0; for (const auto& type : storage.operators[op].argument_types) { if (has_terminals.contains(type)) terminals++; } ordered_terminals.emplace_back(op, terminals); } bool found_terminal_inputs = false; bool matches_argc = false; for (const auto& terms : ordered_terminals) { if (terms.second == storage.operators[terms.first].argc.argc) matches_argc = true; if (terms.second != 0) found_terminal_inputs = true; if (matches_argc && found_terminal_inputs) break; } if (!found_terminal_inputs) BLT_ABORT(("Failed to find function with terminal arguments for return type " + std::to_string(return_type)).c_str()); if (!matches_argc) { BLT_ABORT(("Failed to find a function which purely translates types " "(that is all input types are terminals) for return type " + std::to_string(return_type)).c_str()); } std::sort(ordered_terminals.begin(), ordered_terminals.end(), [](const auto& a, const auto& b) { return a.second > b.second; }); auto first_size = *ordered_terminals.begin(); auto iter = ordered_terminals.begin(); while (++iter != ordered_terminals.end() && iter->second == first_size.second) {} ordered_terminals.erase(iter, ordered_terminals.end()); storage.operators_ordered_terminals[return_type] = ordered_terminals; } return std::move(storage); } private: template void add_non_context_argument(decltype(operator_info::argument_types)& types) { if constexpr (!std::is_same_v>) { types.push_back(system.get_type().id()); } } type_provider& system; operator_storage storage; }; 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_provider& system, random_t engine): system(system), engine(engine) {} explicit gp_program(type_provider& system, random_t engine, prog_config_t config): system(system), engine(engine), config(config) {} void generate_population(type_id root_type) { current_pop = config.pop_initializer.get().generate( {*this, root_type, config.population_size, config.initial_min_tree_size, config.initial_max_tree_size}); } template)> void create_next_generation(Crossover&& crossover_selection, Mutation&& mutation_selection, Reproduction&& reproduction_selection, Creation_Func& func = default_next_pop_creator) { // should already be empty next_pop.clear(); crossover_selection.pre_process(*this, current_pop, current_stats); mutation_selection.pre_process(*this, current_pop, current_stats); reproduction_selection.pre_process(*this, current_pop, current_stats); func(get_selector_args(), std::forward(crossover_selection), std::forward(mutation_selection), std::forward(reproduction_selection)); } /** * takes in a lambda for the fitness evaluation function (must return a value convertable to double) * The lambda must accept a tree for evaluation, container for evaluation context, and a index into that container (current tree) * * tree_t&, Container&, blt::size_t * * Container must be concurrently accessible from multiple threads using operator[] * * NOTE: 0 is considered the best, in terms of standardized and adjusted fitness */ template void evaluate_fitness(Callable&& fitness_function, Container& result_storage, bool larger_better = true) { for (const auto& ind : blt::enumerate(current_pop.get_individuals())) ind.second.raw_fitness = static_cast(fitness_function(ind.second.tree, result_storage, ind.first)); double min = 0; double max = 0; for (auto& ind : current_pop.get_individuals()) { if (ind.raw_fitness < min) min = ind.raw_fitness; if (larger_better && ind.raw_fitness > max) max = ind.raw_fitness; } double overall_fitness = 0; double best_fitness = 2; double worst_fitness = 0; individual* best = nullptr; individual* worst = nullptr; auto diff = -min; for (auto& ind : current_pop.get_individuals()) { // make standardized fitness [0, +inf) auto standardized_fitness = ind.raw_fitness + diff; BLT_WARN(standardized_fitness); if (larger_better) standardized_fitness = (max + diff) - standardized_fitness; BLT_WARN(standardized_fitness); ind.adjusted_fitness = (1.0 / (1.0 + standardized_fitness)); if (ind.adjusted_fitness > worst_fitness) { worst_fitness = ind.adjusted_fitness; worst = &ind; } if (ind.adjusted_fitness < best_fitness) { best_fitness = ind.adjusted_fitness; best = &ind; } overall_fitness += ind.adjusted_fitness; } current_stats = {overall_fitness, overall_fitness / static_cast(config.population_size), best_fitness, worst_fitness, best, worst}; } void next_generation() { current_pop = std::move(next_pop); current_generation++; } inline auto& get_current_pop() { return current_pop; } template std::array get_best_indexes() { std::array arr; std::vector> values; values.reserve(current_pop.get_individuals().size()); for (const auto& ind : blt::enumerate(current_pop.get_individuals())) values.emplace_back(ind.first, ind.second.adjusted_fitness); std::sort(values.begin(), values.end(), [](const auto& a, const auto& b) { return a.second < b.second; }); for (blt::size_t i = 0; i < size; i++) arr[i] = values[i].first; return arr; } template std::array, size> get_best() { return convert_array(get_best_indexes(), std::make_integer_sequence()); } [[nodiscard]] bool should_terminate() const { return current_generation >= config.max_generations; } [[nodiscard]] inline random_t& get_random() { return engine; } [[nodiscard]] inline type_provider& get_typesystem() { return system; } inline operator_id select_terminal(type_id id) { // we wanted a terminal, but could not find one, so we will select from a function that has a terminal if (storage.terminals[id].empty()) return select_non_terminal_too_deep(id); return storage.terminals[id][engine.get_size_t(0, storage.terminals[id].size())]; } inline operator_id select_non_terminal(type_id id) { return storage.non_terminals[id][engine.get_size_t(0, storage.non_terminals[id].size())]; } inline operator_id select_non_terminal_too_deep(type_id id) { return storage.operators_ordered_terminals[id][engine.get_size_t(0, storage.operators_ordered_terminals[id].size())].first; } inline operator_info& get_operator_info(operator_id id) { return storage.operators[id]; } inline detail::print_func_t& get_print_func(operator_id id) { return storage.print_funcs[id]; } inline std::optional get_name(operator_id id) { return storage.names[id]; } inline std::vector& get_type_terminals(type_id id) { return storage.terminals[id]; } inline std::vector& get_type_non_terminals(type_id id) { return storage.non_terminals[id]; } inline bool is_static(operator_id id) { return storage.static_types.contains(static_cast(id)); } inline void set_operations(operator_storage&& op) { storage = std::move(op); } [[nodiscard]] inline auto get_current_generation() const { return current_generation; } private: type_provider& system; blt::gp::stack_allocator alloc; operator_storage storage; population_t current_pop; population_stats current_stats; population_t next_pop; blt::size_t current_generation = 0; random_t engine; prog_config_t config; inline selector_args get_selector_args() { return {*this, next_pop, current_pop, current_stats, config, engine}; } template inline std::array, size> convert_array(std::array&& arr, std::integer_sequence) { return {current_pop.get_individuals()[arr[indexes]].tree...}; } }; } #endif //BLT_GP_PROGRAM_H