blt-gp/src/transformers.cpp

/*
 *  <Short Description>
 *  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/>.
 */
#include <blt/gp/transformers.h>
#include <blt/gp/program.h>
#include <blt/std/ranges.h>
#include <blt/std/utility.h>
#include <algorithm>
#include <blt/std/memory.h>
#include <blt/profiling/profiler_v2.h>
#include <random>

namespace blt::gp
{
    
    grow_generator_t grow_generator;
    
    inline tree_t& get_static_tree_tl(gp_program& program)
    {
        static thread_local tree_t new_tree{program};
        new_tree.clear(program);
        return new_tree;
    }
    
    inline blt::size_t accumulate_type_sizes(detail::op_iter_t begin, detail::op_iter_t end)
    {
        blt::size_t total = 0;
        for (auto it = begin; it != end; ++it)
        {
            if (it->is_value)
                total += stack_allocator::aligned_size(it->type_size);
        }
        return total;
    }
    
    template<typename>
    blt::u8* get_thread_pointer_for_size(blt::size_t bytes)
    {
        static thread_local blt::expanding_buffer<blt::u8> buffer;
        if (bytes > buffer.size())
            buffer.resize(bytes);
        return buffer.data();
    }
    
    mutation_t::config_t::config_t(): generator(grow_generator)
    {}
    
    bool crossover_t::apply(gp_program& program, const tree_t& p1, const tree_t& p2, tree_t& c1, tree_t& c2) // NOLINT
    {
        c1.copy_fast(p1);
        c2.copy_fast(p2);
        
        auto& c1_ops = c1.get_operations();
        auto& c2_ops = c2.get_operations();
        
        if (c1_ops.size() < 5 || c2_ops.size() < 5)
            return false;
        
        auto point = get_crossover_point(program, p1, p2);
        
        if (!point)
            return false;
        
        auto crossover_point_begin_itr = c1_ops.begin() + point->p1_crossover_point;
        auto crossover_point_end_itr = c1_ops.begin() + c1.find_endpoint(program, point->p1_crossover_point);
        
        auto found_point_begin_itr = c2_ops.begin() + point->p2_crossover_point;
        auto found_point_end_itr = c2_ops.begin() + c2.find_endpoint(program, point->p2_crossover_point);
        
        stack_allocator& c1_stack = c1.get_values();
        stack_allocator& c2_stack = c2.get_values();
        
        // we have to make a copy because we will modify the underlying storage.
        static thread_local std::vector<op_container_t> c1_operators;
        static thread_local std::vector<op_container_t> c2_operators;
        
        c1_operators.clear();
        c2_operators.clear();
        
        for (const auto& op : blt::iterate(crossover_point_begin_itr, crossover_point_end_itr))
            c1_operators.push_back(op);
        for (const auto& op : blt::iterate(found_point_begin_itr, found_point_end_itr))
            c2_operators.push_back(op);
        
        blt::size_t c1_stack_after_bytes = accumulate_type_sizes(crossover_point_end_itr, c1_ops.end());
        blt::size_t c1_stack_for_bytes = accumulate_type_sizes(crossover_point_begin_itr, crossover_point_end_itr);
        blt::size_t c2_stack_after_bytes = accumulate_type_sizes(found_point_end_itr, c2_ops.end());
        blt::size_t c2_stack_for_bytes = accumulate_type_sizes(found_point_begin_itr, found_point_end_itr);
        auto c1_total = static_cast<blt::ptrdiff_t>(c1_stack_after_bytes + c1_stack_for_bytes);
        auto c2_total = static_cast<blt::ptrdiff_t>(c2_stack_after_bytes + c2_stack_for_bytes);
        auto copy_ptr_c1 = get_thread_pointer_for_size<struct c1_t>(c1_total);
        auto copy_ptr_c2 = get_thread_pointer_for_size<struct c2_t>(c2_total);
        
        c1_stack.copy_to(copy_ptr_c1, c1_total);
        c1_stack.pop_bytes(c1_total);
        
        c2_stack.copy_to(copy_ptr_c2, c2_total);
        c2_stack.pop_bytes(c2_total);
        
        c2_stack.copy_from(copy_ptr_c1, c1_stack_for_bytes);
        c2_stack.copy_from(copy_ptr_c2 + c2_stack_for_bytes, c2_stack_after_bytes);
        
        c1_stack.copy_from(copy_ptr_c2, c2_stack_for_bytes);
        c1_stack.copy_from(copy_ptr_c1 + c1_stack_for_bytes, c1_stack_after_bytes);
        
        // now swap the operators
        auto insert_point_c1 = crossover_point_begin_itr - 1;
        auto insert_point_c2 = found_point_begin_itr - 1;
        
        // invalidates [begin, end()) so the insert points should be fine
        c1_ops.erase(crossover_point_begin_itr, crossover_point_end_itr);
        c2_ops.erase(found_point_begin_itr, found_point_end_itr);
        
        c1_ops.insert(++insert_point_c1, c2_operators.begin(), c2_operators.end());
        c2_ops.insert(++insert_point_c2, c1_operators.begin(), c1_operators.end());

#if BLT_DEBUG_LEVEL >= 2
        blt::size_t c1_found_bytes = c1.get_values().size().total_used_bytes;
        blt::size_t c2_found_bytes = c2.get_values().size().total_used_bytes;
        blt::size_t c1_expected_bytes = std::accumulate(result.child1.get_operations().begin(), result.child1.get_operations().end(), 0ul,
                                                        [](const auto& v1, const auto& v2) {
                                                            if (v2.is_value)
                                                                return v1 + stack_allocator::aligned_size(v2.type_size);
                                                            return v1;
                                                        });
        blt::size_t c2_expected_bytes = std::accumulate(result.child2.get_operations().begin(), result.child2.get_operations().end(), 0ul,
                                                        [](const auto& v1, const auto& v2) {
                                                            if (v2.is_value)
                                                                return v1 + stack_allocator::aligned_size(v2.type_size);
                                                            return v1;
                                                        });
        if (c1_found_bytes != c1_expected_bytes || c2_found_bytes != c2_expected_bytes)
        {
            BLT_WARN("C1 Found bytes %ld vs Expected Bytes %ld", c1_found_bytes, c1_expected_bytes);
            BLT_WARN("C2 Found bytes %ld vs Expected Bytes %ld", c2_found_bytes, c2_expected_bytes);
            BLT_ABORT("Amount of bytes in stack doesn't match the number of bytes expected for the operations");
        }
#endif
        
        return true;
    }
    
    std::optional<crossover_t::crossover_point_t> crossover_t::get_crossover_point(gp_program& program, const tree_t& c1,
                                                                                                         const tree_t& c2) const
    {
        auto& c1_ops = c1.get_operations();
        auto& c2_ops = c2.get_operations();
        
        blt::size_t crossover_point = program.get_random().get_size_t(1ul, c1_ops.size());
        
        while (config.avoid_terminals && program.get_operator_info(c1_ops[crossover_point].id).argc.is_terminal())
            crossover_point = program.get_random().get_size_t(1ul, c1_ops.size());
        
        blt::size_t attempted_point = 0;
        
        const auto& crossover_point_type = program.get_operator_info(c1_ops[crossover_point].id);
        operator_info* attempted_point_type = nullptr;
        
        blt::size_t counter = 0;
        do
        {
            if (counter >= config.max_crossover_tries)
            {
                if (config.should_crossover_try_forward)
                {
                    bool found = false;
                    for (auto i = attempted_point + 1; i < c2_ops.size(); i++)
                    {
                        auto* info = &program.get_operator_info(c2_ops[i].id);
                        if (info->return_type == crossover_point_type.return_type)
                        {
                            if (config.avoid_terminals && info->argc.is_terminal())
                                continue;
                            attempted_point = i;
                            attempted_point_type = info;
                            found = true;
                            break;
                        }
                    }
                    if (!found)
                        return {};
                }
                // should we try again over the whole tree? probably not.
                return {};
            } else
            {
                attempted_point = program.get_random().get_size_t(1ul, c2_ops.size());
                attempted_point_type = &program.get_operator_info(c2_ops[attempted_point].id);
                if (config.avoid_terminals && attempted_point_type->argc.is_terminal())
                    continue;
                if (crossover_point_type.return_type == attempted_point_type->return_type)
                    break;
                counter++;
            }
        } while (true);
        
        return crossover_point_t{static_cast<blt::ptrdiff_t>(crossover_point), static_cast<blt::ptrdiff_t>(attempted_point)};
    }
    
    bool mutation_t::apply(gp_program& program, const tree_t& p, tree_t& c)
    {
        c.copy_fast(p);
        
        mutate_point(program, c, program.get_random().get_size_t(0ul, c.get_operations().size()));
        
        return true;
    }
    
    blt::size_t mutation_t::mutate_point(gp_program& program, tree_t& c, blt::size_t node)
    {
        auto& ops_r = c.get_operations();
        auto& vals_r = c.get_values();
        
        auto begin_point = static_cast<blt::ptrdiff_t>(node);
        auto end_point = c.find_endpoint(program, begin_point);
        auto begin_operator_id = ops_r[begin_point].id;
        const auto& type_info = program.get_operator_info(begin_operator_id);
        
        auto begin_itr = ops_r.begin() + begin_point;
        auto end_itr = ops_r.begin() + end_point;
        
        auto& new_tree = get_static_tree_tl(program);
        config.generator.get().generate(new_tree, {program, type_info.return_type, config.replacement_min_depth, config.replacement_max_depth});
        
        auto& new_ops_r = new_tree.get_operations();
        auto& new_vals_r = new_tree.get_values();
        
        blt::size_t total_bytes_after = accumulate_type_sizes(end_itr, ops_r.end());
        auto* stack_after_data = get_thread_pointer_for_size<struct mutation>(total_bytes_after);
        
        // make a copy of any stack data after the mutation point / children.
        vals_r.copy_to(stack_after_data, total_bytes_after);
        
        // remove the bytes of the data after the mutation point and the data for the children of the mutation node.
        vals_r.pop_bytes(static_cast<blt::ptrdiff_t>(total_bytes_after + accumulate_type_sizes(begin_itr, end_itr)));
        
        // insert the new tree then move back the data from after the original mutation point.
        vals_r.insert(new_vals_r);
        vals_r.copy_from(stack_after_data, total_bytes_after);
        
        auto before = begin_itr - 1;
        ops_r.erase(begin_itr, end_itr);
        ops_r.insert(++before, new_ops_r.begin(), new_ops_r.end());
        
        // this will check to make sure that the tree is in a correct and executable state. it requires that the evaluation is context free!
#if BLT_DEBUG_LEVEL >= 2
        //        BLT_ASSERT(new_vals_r.empty());
                //BLT_ASSERT(stack_after.empty());
                blt::size_t bytes_expected = 0;
                auto bytes_size = vals_r.size().total_used_bytes;
                
                for (const auto& op : c.get_operations())
                {
                    if (op.is_value)
                        bytes_expected += stack_allocator::aligned_size(op.type_size);
                }
                
                if (bytes_expected != bytes_size)
                {
                    BLT_WARN_STREAM << "Stack state: " << vals_r.size() << "\n";
                    BLT_WARN("Child tree bytes %ld vs expected %ld, difference: %ld", bytes_size, bytes_expected,
                             static_cast<blt::ptrdiff_t>(bytes_expected) - static_cast<blt::ptrdiff_t>(bytes_size));
                    BLT_TRACE("Total bytes after: %ld", total_bytes_after);
                    BLT_ABORT("Amount of bytes in stack doesn't match the number of bytes expected for the operations");
                }
                auto copy = c;
                try
                {
                    auto result = copy.evaluate(nullptr);
                    blt::black_box(result);
                } catch (...)
                {
                    std::cout << "This occurred at point " << begin_point << " ending at (old) " << end_point << "\n";
                    std::cout << "our root type is " << ops_r[begin_point].id << " with size " << stack_allocator::aligned_size(ops_r[begin_point].type_size)
                              << "\n";
                    std::cout << "now Named: " << (program.get_name(ops_r[begin_point].id) ? *program.get_name(ops_r[begin_point].id) : "Unnamed") << "\n";
                    std::cout << "Was named: " << (program.get_name(begin_operator_id) ? *program.get_name(begin_operator_id) : "Unnamed") << "\n";
                    //std::cout << "Parent:" << std::endl;
                    //p.print(program, std::cout, false, true);
                    std::cout << "Child:" << std::endl;
                    c.print(program, std::cout, false, true);
                    std::cout << std::endl;
                    c.print(program, std::cout, true, true);
                    std::cout << std::endl;
                    throw std::exception();
                }
#endif
        return begin_point + new_ops_r.size();
    }
    
    bool advanced_mutation_t::apply(gp_program& program, const tree_t& p, tree_t& c)
    {
        // child tree
        c.copy_fast(p);
        
        auto& ops = c.get_operations();
        auto& vals = c.get_values();
        
        for (blt::size_t c_node = 0; c_node < ops.size(); c_node++)
        {
            double node_mutation_chance = per_node_mutation_chance / static_cast<double>(ops.size());
            if (!program.get_random().choice(node_mutation_chance))
                continue;

#if BLT_DEBUG_LEVEL >= 2
            tree_t c_copy = c;
#endif
            
            // select an operator to apply
            auto selected_point = static_cast<blt::i32>(mutation_operator::COPY);
            auto choice = program.get_random().get_double();
            for (const auto& [index, value] : blt::enumerate(mutation_operator_chances))
            {
                if (index == 0)
                {
                    if (choice <= value)
                    {
                        selected_point = static_cast<blt::i32>(index);
                        break;
                    }
                } else
                {
                    if (choice > mutation_operator_chances[index - 1] && choice <= value)
                    {
                        selected_point = static_cast<blt::i32>(index);
                        break;
                    }
                }
            }
            
            switch (static_cast<mutation_operator>(selected_point))
            {
                case mutation_operator::EXPRESSION:
                    c_node += mutate_point(program, c, c_node);
                    break;
                case mutation_operator::ADJUST:
                {
                    // this is going to be evil >:3
                    const auto& node = ops[c_node];
                    if (!node.is_value)
                    {
                        auto& current_func_info = program.get_operator_info(ops[c_node].id);
                        operator_id random_replacement = program.get_random().select(
                                program.get_type_non_terminals(current_func_info.return_type.id));
                        auto& replacement_func_info = program.get_operator_info(random_replacement);
                        
                        // cache memory used for offset data.
                        thread_local static std::vector<tree_t::child_t> children_data;
                        children_data.clear();
                        
                        c.find_child_extends(program, children_data, c_node, current_func_info.argument_types.size());
                        
                        for (const auto& [index, val] : blt::enumerate(replacement_func_info.argument_types))
                        {
                            // need to generate replacement.
                            if (index < current_func_info.argument_types.size() && val.id != current_func_info.argument_types[index].id)
                            {
                                // TODO: new config?
                                auto& tree = get_static_tree_tl(program);
                                config.generator.get().generate(tree,
                                        {program, val.id, config.replacement_min_depth, config.replacement_max_depth});
                                
                                auto& child = children_data[children_data.size() - 1 - index];
                                blt::size_t total_bytes_for = c.total_value_bytes(child.start, child.end);
                                blt::size_t total_bytes_after = c.total_value_bytes(child.end);
                                
                                auto after_ptr = get_thread_pointer_for_size<struct mutation_func>(total_bytes_after);
                                vals.copy_to(after_ptr, total_bytes_after);
                                vals.pop_bytes(static_cast<blt::ptrdiff_t>(total_bytes_after + total_bytes_for));
                                
                                blt::size_t total_child_bytes = tree.total_value_bytes();
                                
                                vals.copy_from(tree.get_values(), total_child_bytes);
                                vals.copy_from(after_ptr, total_bytes_after);
                                
                                ops.erase(ops.begin() + child.start, ops.begin() + child.end);
                                ops.insert(ops.begin() + child.start, tree.get_operations().begin(), tree.get_operations().end());
                                
                                // shift over everybody after.
                                if (index > 0)
                                {
                                    // don't need to update if the index is the last
                                    for (auto& new_child : blt::iterate(children_data.end() - static_cast<blt::ptrdiff_t>(index),
                                                                        children_data.end()))
                                    {
                                        // remove the old tree size, then add the new tree size to get the correct positions.
                                        new_child.start =
                                                new_child.start - (child.end - child.start) +
                                                static_cast<blt::ptrdiff_t>(tree.get_operations().size());
                                        new_child.end =
                                                new_child.end - (child.end - child.start) + static_cast<blt::ptrdiff_t>(tree.get_operations().size());
                                    }
                                }
                                child.end = static_cast<blt::ptrdiff_t>(child.start + tree.get_operations().size());

#if BLT_DEBUG_LEVEL >= 2
                                blt::size_t found_bytes = vals.size().total_used_bytes;
                                blt::size_t expected_bytes = std::accumulate(ops.begin(),
                                                                             ops.end(), 0ul,
                                                                             [](const auto& v1, const auto& v2) {
                                                                                 if (v2.is_value)
                                                                                     return v1 + stack_allocator::aligned_size(v2.type_size);
                                                                                 return v1;
                                                                             });
                                if (found_bytes != expected_bytes)
                                {
                                    BLT_WARN("Found bytes %ld vs Expected Bytes %ld", found_bytes, expected_bytes);
                                    BLT_ABORT("Amount of bytes in stack doesn't match the number of bytes expected for the operations");
                                }
#endif
                            }
                        }
                        
                        if (current_func_info.argc.argc > replacement_func_info.argc.argc)
                        {
                            blt::size_t end_index = children_data[(current_func_info.argc.argc - replacement_func_info.argc.argc) - 1].end;
                            blt::size_t start_index = children_data.begin()->start;
                            blt::size_t total_bytes_for = c.total_value_bytes(start_index, end_index);
                            blt::size_t total_bytes_after = c.total_value_bytes(end_index);
                            auto* data = get_thread_pointer_for_size<struct mutation_func>(total_bytes_after);
                            vals.copy_to(data, total_bytes_after);
                            vals.pop_bytes(static_cast<blt::ptrdiff_t>(total_bytes_after + total_bytes_for));
                            vals.copy_from(data, total_bytes_after);
                            ops.erase(ops.begin() + static_cast<blt::ptrdiff_t>(start_index), ops.begin() + static_cast<blt::ptrdiff_t>(end_index));
                        } else if (current_func_info.argc.argc == replacement_func_info.argc.argc)
                        {
                            // exactly enough args
                            // return types should have been replaced if needed. this part should do nothing?
                        } else
                        {
                            // not enough args
                            blt::size_t start_index = c_node + 1;
                            blt::size_t total_bytes_after = c.total_value_bytes(start_index);
                            auto* data = get_thread_pointer_for_size<struct mutation_func>(total_bytes_after);
                            vals.copy_to(data, total_bytes_after);
                            vals.pop_bytes(static_cast<blt::ptrdiff_t>(total_bytes_after));
                            
                            for (blt::ptrdiff_t i = static_cast<blt::ptrdiff_t>(replacement_func_info.argc.argc) - 1;
                                 i >= current_func_info.argc.argc; i--)
                            {
                                auto& tree = get_static_tree_tl(program);
                                config.generator.get().generate(tree,
                                        {program, replacement_func_info.argument_types[i].id, config.replacement_min_depth,
                                         config.replacement_max_depth});
                                blt::size_t total_bytes_for = tree.total_value_bytes();
                                vals.copy_from(tree.get_values(), total_bytes_for);
                                ops.insert(ops.begin() + static_cast<blt::ptrdiff_t>(start_index), tree.get_operations().begin(),
                                           tree.get_operations().end());
                                start_index += tree.get_operations().size();
                            }
                            vals.copy_from(data, total_bytes_after);
                        }
                        // now finally update the type.
                        ops[c_node] = {program.get_typesystem().get_type(replacement_func_info.return_type).size(), random_replacement,
                                       program.is_operator_ephemeral(random_replacement)};
                    }
#if BLT_DEBUG_LEVEL >= 2
                    if (!c.check(program, nullptr))
                    {
                        std::cout << "Parent: " << std::endl;
                        c_copy.print(program, std::cout, false, true);
                        std::cout << "Child Values:" << std::endl;
                        c.print(program, std::cout, true, true);
                        std::cout << std::endl;
                        BLT_ABORT("Tree Check Failed.");
                    }
#endif
                }
                    break;
                case mutation_operator::SUB_FUNC:
                {
                    auto& current_func_info = program.get_operator_info(ops[c_node].id);
                    
                    // need to:
                    // mutate the current function.
                    // current function is moved to one of the arguments.
                    // other arguments are generated.
                    
                    // get a replacement which returns the same type.
                    auto& non_terminals = program.get_type_non_terminals(current_func_info.return_type.id);
                    if (non_terminals.empty())
                        continue;
                    operator_id random_replacement = program.get_random().select(non_terminals);
                    blt::size_t arg_position = 0;
                    do
                    {
                        auto& replacement_func_info = program.get_operator_info(random_replacement);
                        for (const auto& [index, v] : blt::enumerate(replacement_func_info.argument_types))
                        {
                            if (v.id == current_func_info.return_type.id)
                            {
                                arg_position = index;
                                goto exit;
                            }
                        }
                        random_replacement = program.get_random().select(program.get_type_non_terminals(current_func_info.return_type.id));
                    } while (true);
                exit:
                    auto& replacement_func_info = program.get_operator_info(random_replacement);
                    auto new_argc = replacement_func_info.argc.argc;
                    // replacement function should be valid. let's make a copy of us.
                    auto current_end = c.find_endpoint(program, static_cast<blt::ptrdiff_t>(c_node));
                    blt::size_t for_bytes = c.total_value_bytes(c_node, current_end);
                    blt::size_t after_bytes = c.total_value_bytes(current_end);
                    auto size = current_end - c_node;
                    
                    auto combined_ptr = get_thread_pointer_for_size<struct SUB_FUNC_FOR>(for_bytes + after_bytes);
                    
                    vals.copy_to(combined_ptr, for_bytes + after_bytes);
                    vals.pop_bytes(static_cast<blt::ptrdiff_t>(for_bytes + after_bytes));
                    
                    blt::size_t start_index = c_node;
                    for (blt::ptrdiff_t i = new_argc - 1; i > static_cast<blt::ptrdiff_t>(arg_position); i--)
                    {
                        auto& tree = get_static_tree_tl(program);
                        config.generator.get().generate(tree,
                                {program, replacement_func_info.argument_types[i].id, config.replacement_min_depth,
                                 config.replacement_max_depth});
                        blt::size_t total_bytes_for = tree.total_value_bytes();
                        vals.copy_from(tree.get_values(), total_bytes_for);
                        ops.insert(ops.begin() + static_cast<blt::ptrdiff_t>(start_index), tree.get_operations().begin(),
                                   tree.get_operations().end());
                        start_index += tree.get_operations().size();
                    }
                    start_index += size;
                    vals.copy_from(combined_ptr, for_bytes);
                    for (blt::ptrdiff_t i = static_cast<blt::ptrdiff_t>(arg_position) - 1; i >= 0; i--)
                    {
                        auto& tree = get_static_tree_tl(program);
                        config.generator.get().generate(tree,
                                {program, replacement_func_info.argument_types[i].id, config.replacement_min_depth,
                                 config.replacement_max_depth});
                        blt::size_t total_bytes_for = tree.total_value_bytes();
                        vals.copy_from(tree.get_values(), total_bytes_for);
                        ops.insert(ops.begin() + static_cast<blt::ptrdiff_t>(start_index), tree.get_operations().begin(),
                                   tree.get_operations().end());
                        start_index += tree.get_operations().size();
                    }
                    vals.copy_from(combined_ptr + for_bytes, after_bytes);
                    
                    ops.insert(ops.begin() + static_cast<blt::ptrdiff_t>(c_node),
                               {program.get_typesystem().get_type(replacement_func_info.return_type).size(),
                                random_replacement, program.is_operator_ephemeral(random_replacement)});

#if BLT_DEBUG_LEVEL >= 2
                    if (!c.check(program, nullptr))
                    {
                        std::cout << "Parent: " << std::endl;
                        p.print(program, std::cout, false, true);
                        std::cout << "Child:" << std::endl;
                        c.print(program, std::cout, false, true);
                        std::cout << "Child Values:" << std::endl;
                        c.print(program, std::cout, true, true);
                        std::cout << std::endl;
                        BLT_ABORT("Tree Check Failed.");
                    }
#endif
                }
                    break;
                case mutation_operator::JUMP_FUNC:
                {
                    auto& info = program.get_operator_info(ops[c_node].id);
                    blt::size_t argument_index = -1ul;
                    for (const auto& [index, v] : blt::enumerate(info.argument_types))
                    {
                        if (v.id == info.return_type.id)
                        {
                            argument_index = index;
                            break;
                        }
                    }
                    if (argument_index == -1ul)
                        continue;
                    
                    static thread_local std::vector<tree_t::child_t> child_data;
                    child_data.clear();
                    
                    c.find_child_extends(program, child_data, c_node, info.argument_types.size());
                    
                    auto child_index = child_data.size() - 1 - argument_index;
                    auto child = child_data[child_index];
                    auto for_bytes = c.total_value_bytes(child.start, child.end);
                    auto after_bytes = c.total_value_bytes(child_data.back().end);
                    
                    auto storage_ptr = get_thread_pointer_for_size<struct jump_func>(for_bytes + after_bytes);
                    vals.copy_to(storage_ptr + for_bytes, after_bytes);
                    vals.pop_bytes(static_cast<blt::ptrdiff_t>(after_bytes));
                    
                    for (auto i = static_cast<blt::ptrdiff_t>(child_data.size() - 1); i > static_cast<blt::ptrdiff_t>(child_index); i--)
                    {
                        auto& cc = child_data[i];
                        auto bytes = c.total_value_bytes(cc.start, cc.end);
                        vals.pop_bytes(static_cast<blt::ptrdiff_t>(bytes));
                        ops.erase(ops.begin() + cc.start, ops.begin() + cc.end);
                    }
                    vals.copy_to(storage_ptr, for_bytes);
                    vals.pop_bytes(static_cast<blt::ptrdiff_t>(for_bytes));
                    for (auto i = static_cast<blt::ptrdiff_t>(child_index - 1); i >= 0; i--)
                    {
                        auto& cc = child_data[i];
                        auto bytes = c.total_value_bytes(cc.start, cc.end);
                        vals.pop_bytes(static_cast<blt::ptrdiff_t>(bytes));
                        ops.erase(ops.begin() + cc.start, ops.begin() + cc.end);
                    }
                    ops.erase(ops.begin() + static_cast<blt::ptrdiff_t>(c_node));
                    vals.copy_from(storage_ptr, for_bytes + after_bytes);

#if BLT_DEBUG_LEVEL >= 2
                    if (!c.check(program, nullptr))
                    {
                        std::cout << "Parent: " << std::endl;
                        p.print(program, std::cout, false, true);
                        std::cout << "Child Values:" << std::endl;
                        c.print(program, std::cout, true, true);
                        std::cout << std::endl;
                        BLT_ABORT("Tree Check Failed.");
                    }
#endif
                }
                    break;
                case mutation_operator::COPY:
                {
                    auto& info = program.get_operator_info(ops[c_node].id);
                    blt::size_t pt = -1ul;
                    blt::size_t pf = -1ul;
                    for (const auto& [index, v] : blt::enumerate(info.argument_types))
                    {
                        for (blt::size_t i = index + 1; i < info.argument_types.size(); i++)
                        {
                            auto& v1 = info.argument_types[i];
                            if (v == v1)
                            {
                                if (pt == -1ul)
                                    pt = index;
                                else
                                    pf = index;
                                break;
                            }
                        }
                        if (pt != -1ul && pf != -1ul)
                            break;
                    }
                    if (pt == -1ul || pf == -1ul)
                        continue;
                    
                    blt::size_t from = 0;
                    blt::size_t to = 0;
                    
                    if (program.get_random().choice())
                    {
                        from = pt;
                        to = pf;
                    } else
                    {
                        from = pf;
                        to = pt;
                    }
                    
                    static thread_local std::vector<tree_t::child_t> child_data;
                    child_data.clear();
                    
                    c.find_child_extends(program, child_data, c_node, info.argument_types.size());
                    
                    auto from_index = child_data.size() - 1 - from;
                    auto to_index = child_data.size() - 1 - to;
                    auto& from_child = child_data[from_index];
                    auto& to_child = child_data[to_index];
                    blt::size_t from_bytes = c.total_value_bytes(from_child.start, from_child.end);
                    blt::size_t after_from_bytes = c.total_value_bytes(from_child.end);
                    blt::size_t to_bytes = c.total_value_bytes(to_child.start, to_child.end);
                    blt::size_t after_to_bytes = c.total_value_bytes(to_child.end);
                    
                    auto after_bytes = std::max(after_from_bytes, after_to_bytes);
                    
                    auto from_ptr = get_thread_pointer_for_size<struct copy>(from_bytes);
                    auto after_ptr = get_thread_pointer_for_size<struct copy_after>(after_bytes);
                    
                    vals.copy_to(after_ptr, after_from_bytes);
                    vals.pop_bytes(static_cast<blt::ptrdiff_t>(after_from_bytes));
                    vals.copy_to(from_ptr, from_bytes);
                    vals.copy_from(after_ptr, after_from_bytes);
                    
                    vals.copy_to(after_ptr, after_to_bytes);
                    vals.pop_bytes(static_cast<blt::ptrdiff_t>(after_to_bytes + to_bytes));
                    
                    vals.copy_from(from_ptr, from_bytes);
                    vals.copy_from(after_ptr, after_to_bytes);
                    
                    static thread_local std::vector<op_container_t> op_copy;
                    op_copy.clear();
                    op_copy.insert(op_copy.begin(), ops.begin() + from_child.start, ops.begin() + from_child.end);
                    
                    ops.erase(ops.begin() + to_child.start, ops.begin() + to_child.end);
                    ops.insert(ops.begin() + to_child.start, op_copy.begin(), op_copy.end());
                }
                    break;
                case mutation_operator::END:
                default:
#if BLT_DEBUG_LEVEL > 1
                    BLT_ABORT("You shouldn't be able to get here!");
#else
                    BLT_UNREACHABLE;
#endif
            }
        }

#if BLT_DEBUG_LEVEL >= 2
        if (!c.check(program, nullptr))
        {
            std::cout << "Parent: " << std::endl;
            p.print(program, std::cout, false, true);
            std::cout << "Child Values:" << std::endl;
            c.print(program, std::cout, true, true);
            std::cout << std::endl;
            BLT_ABORT("Tree Check Failed.");
        }
#endif
        
        return true;
    }
}