/* Abstract syntax tree representation.
   Copyright (C) 2025 Free Software Foundation, Inc.

GCC 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, or (at your option)
any later version.

GCC 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 GCC; see the file COPYING3.  If not see
<http://www.gnu.org/licenses/>.  */

#include "elna/boot/ast.h"

#include <utility>

namespace elna::boot
{
    void empty_visitor::visit(array_type_expression *)
    {
        __builtin_unreachable();
    }

    void empty_visitor::visit(pointer_type_expression *)
    {
        __builtin_unreachable();
    }

    void empty_visitor::visit(constant_type_expression *)
    {
        __builtin_unreachable();
    }

    void empty_visitor::visit(type_declaration *)
    {
        __builtin_unreachable();
    }

    void empty_visitor::visit(record_type_expression *)
    {
        __builtin_unreachable();
    }

    void empty_visitor::visit(procedure_type_expression *)
    {
        __builtin_unreachable();
    }

    void empty_visitor::visit(enumeration_type_expression *)
    {
        __builtin_unreachable();
    }

    void empty_visitor::visit(variable_declaration *)
    {
        __builtin_unreachable();
    }

    void empty_visitor::visit(procedure_declaration *)
    {
        __builtin_unreachable();
    }

    void empty_visitor::visit(assign_statement *)
    {
        __builtin_unreachable();
    }

    void empty_visitor::visit(if_statement *)
    {
        __builtin_unreachable();
    }

    void empty_visitor::visit(import_declaration *)
    {
        __builtin_unreachable();
    }

    void empty_visitor::visit(while_statement *)
    {
        __builtin_unreachable();
    }

    void empty_visitor::visit(defer_statement *)
    {
        __builtin_unreachable();
    }

    void empty_visitor::visit(empty_statement *)
    {
        __builtin_unreachable();
    }

    void empty_visitor::visit(case_statement *)
    {
        __builtin_unreachable();
    }

    void empty_visitor::visit(procedure_call *)
    {
        __builtin_unreachable();
    }

    void empty_visitor::visit(unit *)
    {
        __builtin_unreachable();
    }

    void empty_visitor::visit(cast_expression *)
    {
        __builtin_unreachable();
    }

    void empty_visitor::visit(record_constructor_expression *)
    {
        __builtin_unreachable();
    }

    void empty_visitor::visit(array_constructor_expression *)
    {
        __builtin_unreachable();
    }

    void empty_visitor::visit(traits_expression *)
    {
        __builtin_unreachable();
    }

    void empty_visitor::visit(binary_expression *)
    {
        __builtin_unreachable();
    }

    void empty_visitor::visit(unary_expression *)
    {
        __builtin_unreachable();
    }

    void empty_visitor::visit(named_expression *)
    {
        __builtin_unreachable();
    }

    void empty_visitor::visit(array_access_expression *)
    {
        __builtin_unreachable();
    }

    void empty_visitor::visit(field_access_expression *)
    {
        __builtin_unreachable();
    }

    void empty_visitor::visit(dereference_expression *)
    {
        __builtin_unreachable();
    }

    void empty_visitor::visit(literal<std::int32_t> *)
    {
        __builtin_unreachable();
    }

    void empty_visitor::visit(literal<std::uint32_t> *)
    {
        __builtin_unreachable();
    }

    void empty_visitor::visit(literal<double> *)
    {
        __builtin_unreachable();
    }

    void empty_visitor::visit(literal<bool> *)
    {
        __builtin_unreachable();
    }

    void empty_visitor::visit(literal<unsigned char> *)
    {
        __builtin_unreachable();
    }

    void empty_visitor::visit(literal<std::nullptr_t> *)
    {
        __builtin_unreachable();
    }

    void empty_visitor::visit(literal<std::string> *)
    {
        __builtin_unreachable();
    }

    void walking_visitor::visit(import_declaration *)
    {
    }

    void walking_visitor::visit(procedure_declaration *declaration)
    {
        for (const field_declaration& parameter : declaration->heading().parameters)
        {
            parameter.second->accept(this);
        }
        if (declaration->heading().return_type.proper_type != nullptr)
        {
            declaration->heading().return_type.proper_type->accept(this);
        }
        if (declaration->body.has_value())
        {
            for (variable_declaration *variable : declaration->body.value().variables)
            {
                variable->accept(this);
            }
            for (auto *statement : declaration->body.value().entry_point)
            {
                statement->accept(this);
            }
            if (declaration->body.value().return_expression != nullptr)
            {
                declaration->body.value().return_expression->accept(this);
            }
        }
    }

    void walking_visitor::visit(assign_statement *statement)
    {
        statement->lvalue().accept(this);
        statement->rvalue().accept(this);
    }

    void walking_visitor::visit(if_statement *statement)
    {
        statement->branch().prerequisite().accept(this);
        for (auto *branch_statement : statement->branch().statements)
        {
            branch_statement->accept(this);
        }
        for (conditional_statements *branch : statement->branches)
        {
            branch->prerequisite().accept(this);

            for (auto *branch_statement : branch->statements)
            {
                branch_statement->accept(this);
            }
        }
        if (statement->alternative != nullptr)
        {
            for (auto *branch_statement : *statement->alternative)
            {
                branch_statement->accept(this);
            }
        }
    }

    void walking_visitor::visit(while_statement *statement)
    {
        statement->branch().prerequisite().accept(this);
        for (auto *branch_statement : statement->branch().statements)
        {
            branch_statement->accept(this);
        }
        for (conditional_statements *branch : statement->branches)
        {
            branch->prerequisite().accept(this);

            for (auto *branch_statement : branch->statements)
            {
                branch_statement->accept(this);
            }
        }
    }

    void walking_visitor::visit(defer_statement *statement)
    {
        for (auto *block_statement : statement->statements)
        {
            block_statement->accept(this);
        }
    }

    void walking_visitor::visit(empty_statement *)
    {
    }

    void walking_visitor::visit(case_statement *statement)
    {
        statement->condition().accept(this);
        for (const switch_case& case_block : statement->cases)
        {
            for (expression *case_label : case_block.labels)
            {
                case_label->accept(this);
            }
            for (auto *block_statement : case_block.statements)
            {
                block_statement->accept(this);
            }
        }
        if (statement->alternative != nullptr)
        {
            for (auto *block_statement : *statement->alternative)
            {
                block_statement->accept(this);
            }
        }
    }

    void walking_visitor::visit(procedure_call *call)
    {
        call->callable().accept(this);
        for (expression *argument : call->arguments)
        {
            argument->accept(this);
        }
    }

    void walking_visitor::visit(unit *unit)
    {
        for (import_declaration *_import : unit->imports)
        {
            _import->accept(this);
        }
        for (type_declaration *type : unit->types)
        {
            type->accept(this);
        }
        for (variable_declaration *variable : unit->variables)
        {
            variable->accept(this);
        }
        for (procedure_declaration *procedure : unit->procedures)
        {
            procedure->accept(this);
        }
        for (auto *entry_statement : unit->entry_point)
        {
            entry_statement->accept(this);
        }
    }

    void walking_visitor::visit(type_declaration *declaration)
    {
        declaration->underlying_type().accept(this);
    }

    void walking_visitor::visit(variable_declaration *declaration)
    {
        declaration->variable_type().accept(this);
        if (declaration->initializer != nullptr)
        {
            declaration->initializer->accept(this);
        }
    }

    void walking_visitor::visit(array_type_expression *expression)
    {
        expression->base().accept(this);
    }

    void walking_visitor::visit(pointer_type_expression *expression)
    {
        expression->base().accept(this);
    }

    void walking_visitor::visit(constant_type_expression *expression)
    {
        expression->base().accept(this);
    }

    void walking_visitor::visit(record_type_expression *expression)
    {
        for (const field_declaration& field : expression->fields)
        {
            field.second->accept(this);
        }
    }

    void walking_visitor::visit(procedure_type_expression *expression)
    {
        for (const field_declaration& field : expression->parameters)
        {
            field.second->accept(this);
        }
        if (expression->return_type.proper_type != nullptr)
        {
            expression->return_type.proper_type->accept(this);
        }
    }

    void walking_visitor::visit(enumeration_type_expression *)
    {
    }

    void walking_visitor::visit(cast_expression *expression)
    {
        expression->value().accept(this);
        expression->target().accept(this);
    }

    void walking_visitor::visit(record_constructor_expression *expression)
    {
        for (const field_initializer& initializer : expression->field_initializers)
        {
            initializer.value().accept(this);
        }
    }

    void walking_visitor::visit(array_constructor_expression *expression)
    {
        expression->m_element_type->accept(this);
        for (auto *element : expression->elements)
        {
            element->accept(this);
        }
    }

    void walking_visitor::visit(traits_expression *trait)
    {
        if (!trait->arguments.empty())
        {
            trait->arguments.front()->accept(this);
        }
    }

    void walking_visitor::visit(binary_expression *expression)
    {
        expression->lhs().accept(this);
        expression->rhs().accept(this);
    }

    void walking_visitor::visit(unary_expression *expression)
    {
        expression->operand().accept(this);
    }

    void walking_visitor::visit(named_expression *)
    {
    }

    void walking_visitor::visit(array_access_expression *expression)
    {
        expression->base().accept(this);
        expression->index().accept(this);
    }

    void walking_visitor::visit(field_access_expression *expression)
    {
        expression->base().accept(this);
    }

    void walking_visitor::visit(dereference_expression *expression)
    {
        expression->base().accept(this);
    }

    void walking_visitor::visit(literal<std::int32_t> *)
    {
    }

    void walking_visitor::visit(literal<std::uint32_t> *)
    {
    }

    void walking_visitor::visit(literal<double> *)
    {
    }

    void walking_visitor::visit(literal<bool> *)
    {
    }

    void walking_visitor::visit(literal<unsigned char> *)
    {
    }

    void walking_visitor::visit(literal<std::nullptr_t> *)
    {
    }

    void walking_visitor::visit(literal<std::string> *)
    {
    }

    node::node(const source_position position)
        : m_position(position)
    {
    }

    node::~node() = default;

    const source_position& node::position() const
    {
        return this->m_position;
    }

    cast_expression *expression::is_cast()
    {
        return nullptr;
    }

    traits_expression *expression::is_traits()
    {
        return nullptr;
    }

    binary_expression *expression::is_binary()
    {
        return nullptr;
    }

    unary_expression *expression::is_unary()
    {
        return nullptr;
    }

    designator_expression *expression::is_designator()
    {
        return nullptr;
    }

    procedure_call *expression::is_call_expression()
    {
        return nullptr;
    }

    literal_expression *expression::is_literal()
    {
        return nullptr;
    }

    record_constructor_expression *expression::is_record_constructor()
    {
        return nullptr;
    }

    array_constructor_expression *expression::is_array_constructor()
    {
        return nullptr;
    }

    named_expression *type_expression::is_named()
    {
        return nullptr;
    }

    array_type_expression *type_expression::is_array()
    {
        return nullptr;
    }

    pointer_type_expression *type_expression::is_pointer()
    {
        return nullptr;
    }

    constant_type_expression *type_expression::is_constant()
    {
        return nullptr;
    }

    record_type_expression *type_expression::is_record()
    {
        return nullptr;
    }

    procedure_type_expression *type_expression::is_procedure()
    {
        return nullptr;
    }

    enumeration_type_expression *type_expression::is_enumeration()
    {
        return nullptr;
    }

    array_type_expression::array_type_expression(const source_position position,
            type_expression *base, const std::uint32_t size)
        : node(position), m_base(base), size(size)
    {
    }

    array_type_expression::~array_type_expression()
    {
        delete m_base;
    }

    void array_type_expression::accept(parser_visitor *visitor)
    {
        visitor->visit(this);
    }

    array_type_expression *array_type_expression::is_array()
    {
        return this;
    }

    type_expression& array_type_expression::base()
    {
        return *m_base;
    }

    pointer_type_expression::pointer_type_expression(const source_position position,
            type_expression *base)
        : node(position), m_base(base)
    {
    }

    pointer_type_expression::~pointer_type_expression()
    {
        delete m_base;
    }

    void pointer_type_expression::accept(parser_visitor *visitor)
    {
        visitor->visit(this);
    }

    pointer_type_expression *pointer_type_expression::is_pointer()
    {
        return this;
    }

    type_expression& pointer_type_expression::base()
    {
        return *m_base;
    }

    constant_type_expression::constant_type_expression(const source_position position,
            type_expression *base)
        : node(position), m_base(base)
    {
    }

    constant_type_expression::~constant_type_expression()
    {
        delete m_base;
    }

    void constant_type_expression::accept(parser_visitor *visitor)
    {
        visitor->visit(this);
    }

    constant_type_expression *constant_type_expression::is_constant()
    {
        return this;
    }

    type_expression& constant_type_expression::base()
    {
        return *m_base;
    }

    record_type_expression::record_type_expression(const source_position position,
            std::vector<field_declaration>&& fields)
        : node(position), fields(std::move(fields))
    {
    }

    record_type_expression::record_type_expression(const source_position position,
            std::vector<field_declaration>&& fields, identifier&& base)
        : node(position), fields(std::move(fields)), base(std::make_optional<identifier>(std::move(base)))
    {
    }

    void record_type_expression::accept(parser_visitor *visitor)
    {
        visitor->visit(this);
    }

    record_type_expression *record_type_expression::is_record()
    {
        return this;
    }

    field_initializer::field_initializer(identifier name, expression *value)
        : m_name(std::move(name)), m_value(value)
    {
    }

    field_initializer::~field_initializer()
    {
        delete this->m_value;
    }

    field_initializer::field_initializer(field_initializer&& other) noexcept
        : m_name(std::move(other.m_name)), m_value(other.m_value)
    {
        other.m_value = nullptr;
    }

    field_initializer& field_initializer::operator=(field_initializer&& other) noexcept
    {
        delete this->m_value;
        this->m_name = std::move(other.m_name);
        this->m_value = other.m_value;
        other.m_value = nullptr;
        return *this;
    }

    const std::string& field_initializer::name() const
    {
        return this->m_name.name();
    }

    const identifier& field_initializer::id() const
    {
        return this->m_name;
    }

    expression& field_initializer::value() const
    {
        return *this->m_value;
    }

    record_constructor_expression::record_constructor_expression(const source_position position,
            identifier&& type_name,
            std::vector<field_initializer>&& field_initializers)
        : node(position), type_name(std::move(type_name)), field_initializers(std::move(field_initializers))
    {
    }

    void record_constructor_expression::accept(parser_visitor *visitor)
    {
        visitor->visit(this);
    }

    record_constructor_expression *record_constructor_expression::is_record_constructor()
    {
        return this;
    }

    array_constructor_expression::array_constructor_expression(const source_position position,
            std::uint32_t size, type_expression *element_type,
            std::vector<expression *>&& elements)
        : node(position), size(size), m_element_type(element_type), elements(std::move(elements))
    {
    }

    void array_constructor_expression::accept(parser_visitor *visitor)
    {
        visitor->visit(this);
    }

    array_constructor_expression *array_constructor_expression::is_array_constructor()
    {
        return this;
    }

    array_constructor_expression::~array_constructor_expression()
    {
        delete m_element_type;
        for (const expression *element : elements)
        {
            delete element;
        }
    }

    variable_declaration::variable_declaration(const source_position position,
            std::vector<identifier_definition>&& identifier, std::shared_ptr<type_expression> variable_type,
            expression *initializer)
        : node(position), m_variable_type(std::move(variable_type)), identifiers(std::move(identifier)), initializer(initializer)
    {
    }

    variable_declaration::variable_declaration(const source_position position,
            std::vector<identifier_definition>&& identifier, std::shared_ptr<type_expression> variable_type,
            std::monostate)
        : node(position), m_variable_type(std::move(variable_type)), identifiers(std::move(identifier)), is_extern(true)
    {
    }

    void variable_declaration::accept(parser_visitor *visitor)
    {
        visitor->visit(this);
    }

    bool variable_declaration::has_initializer() const
    {
        return this->is_extern || this->initializer != nullptr;
    }

    type_expression& variable_declaration::variable_type()
    {
        return *m_variable_type;
    }

    declaration::declaration(const source_position position, identifier_definition identifier)
        : node(position), identifier(std::move(identifier))
    {
    }

    procedure_type_expression::procedure_type_expression(const source_position position,
            std::vector<field_declaration>&& parameters, return_t return_type)
        : node(position), return_type(return_type), parameters(std::move(parameters))
    {
    }

    procedure_type_expression::~procedure_type_expression()
    {
        delete return_type.proper_type;
    }

    void procedure_type_expression::accept(parser_visitor *visitor)
    {
        visitor->visit(this);
    }

    procedure_type_expression *procedure_type_expression::is_procedure()
    {
        return this;
    }

    enumeration_type_expression::enumeration_type_expression(const source_position position,
            std::vector<identifier>&& members)
        : node(position), members(std::move(members))
    {
    }

    void enumeration_type_expression::accept(parser_visitor *visitor)
    {
        visitor->visit(this);
    }

    enumeration_type_expression *enumeration_type_expression::is_enumeration()
    {
        return this;
    }

    procedure_declaration::procedure_declaration(const source_position position, identifier_definition identifier,
            procedure_type_expression *heading, procedure_body&& body)
        : declaration(position, std::move(identifier)), m_heading(heading),
        body(std::make_optional<procedure_body>(std::move(body)))
    {
    }

    procedure_declaration::procedure_declaration(const source_position position, identifier_definition identifier,
            procedure_type_expression *heading)
        : declaration(position, std::move(identifier)), m_heading(heading)
    {
    }

    void procedure_declaration::accept(parser_visitor *visitor)
    {
        visitor->visit(this);
    }

    procedure_type_expression& procedure_declaration::heading()
    {
        return *m_heading;
    }

    procedure_declaration::~procedure_declaration()
    {
        delete m_heading;
    }

    type_declaration::type_declaration(const source_position position, identifier_definition identifier,
            type_expression *underlying_type)
        : declaration(position, std::move(identifier)), m_underlying_type(underlying_type)
    {
    }

    type_declaration::~type_declaration()
    {
        delete m_underlying_type;
    }

    void type_declaration::accept(parser_visitor *visitor)
    {
        visitor->visit(this);
    }

    type_expression& type_declaration::underlying_type()
    {
        return *m_underlying_type;
    }

    procedure_body::procedure_body(std::vector<variable_declaration *>&& variables,
            std::vector<statement *>&& entry_point, expression *return_expression)
        : variables(std::move(variables)),
        entry_point(std::move(entry_point)), return_expression(return_expression)
    {
    }

    procedure_body::procedure_body(procedure_body&& that)
        : variables(std::move(const_cast<std::vector<variable_declaration *>&>(that.variables))),
        entry_point(std::move(const_cast<std::vector<statement *>&>(that.entry_point))),
        return_expression(that.return_expression)
    {
    }

    procedure_body::~procedure_body()
    {
        for (const statement *body_statement : this->entry_point)
        {
            delete body_statement;
        }
        for (const variable_declaration *variable : this->variables)
        {
            delete variable;
        }
    }

    unit::unit(const source_position position)
        : node(position),
        procedure_body(std::vector<variable_declaration *>{}, std::vector<statement *>{}, nullptr)
    {
    }

    unit::unit(const source_position position,
            std::vector<import_declaration *>&& imports,
            std::vector<type_declaration *>&& types,
            std::vector<variable_declaration *>&& variables,
            std::vector<procedure_declaration *>&& procedures,
            std::vector<statement *>&& entry_point)
        : node(position),
        procedure_body(std::move(variables), std::move(entry_point)),
        imports(std::move(imports)), types(std::move(types)), procedures(std::move(procedures))
    {
    }

    void unit::accept(parser_visitor *visitor)
    {
        visitor->visit(this);
    }

    bool unit::has_body() const
    {
        return !this->entry_point.empty();
    }

    unit::~unit()
    {
        for (const procedure_declaration *procedure : this->procedures)
        {
            delete procedure;
        }
        for (const type_declaration *type : this->types)
        {
            delete type;
        }
        for (const import_declaration *declaration : this->imports)
        {
            delete declaration;
        }
    }

    literal_expression *literal_expression::is_literal()
    {
        return this;
    }

    defer_statement::defer_statement(const source_position position, std::vector<statement *>&& statements)
        : node(position), statements(std::move(statements))
    {
    }

    void defer_statement::accept(parser_visitor *visitor)
    {
        visitor->visit(this);
    }

    defer_statement::~defer_statement()
    {
        for (const statement *body_statement : statements)
        {
            delete body_statement;
        }
    }

    void empty_statement::accept(parser_visitor *visitor)
    {
        visitor->visit(this);
    }

    empty_statement::empty_statement(const source_position position)
        : node(position)
    {
    }

    designator_expression::~designator_expression() = default;

    designator_expression *designator_expression::is_designator()
    {
        return this;
    }

    void designator_expression::accept(parser_visitor *visitor)
    {
        if (named_expression *node = is_named())
        {
            visitor->visit(node);
        }
        else if (array_access_expression *node = is_array_access())
        {
            visitor->visit(node);
        }
        else if (field_access_expression *node = is_field_access())
        {
            visitor->visit(node);
        }
        else if (dereference_expression *node = is_dereference())
        {
            visitor->visit(node);
        }
        else
        {
            __builtin_unreachable();
        }
    }

    named_expression::named_expression(const source_position position, const std::string& name)
        : node(position), name(name)
    {
    }

    void named_expression::accept(parser_visitor *visitor)
    {
        visitor->visit(this);
    }

    named_expression *named_expression::is_named()
    {
        return this;
    }

    array_access_expression::array_access_expression(const source_position position,
            expression *base, expression *index)
        : node(position), m_base(base), m_index(index)
    {
    }

    void array_access_expression::accept(parser_visitor *visitor)
    {
        visitor->visit(this);
    }

    expression& array_access_expression::index()
    {
        return *m_index;
    }

    expression& array_access_expression::base()
    {
        return *m_base;
    }

    array_access_expression *array_access_expression::is_array_access()
    {
        return this;
    }

    array_access_expression::~array_access_expression()
    {
        delete m_index;
        delete m_base;
    }

    field_access_expression::field_access_expression(const source_position position,
            expression *base, identifier&& field)
        : node(position), m_base(base), m_field(std::move(field))
    {
    }

    void field_access_expression::accept(parser_visitor *visitor)
    {
        visitor->visit(this);
    }

    expression& field_access_expression::base()
    {
        return *m_base;
    }

    const identifier& field_access_expression::field()
    {
        return m_field;
    }

    field_access_expression *field_access_expression::is_field_access()
    {
        return this;
    }

    field_access_expression::~field_access_expression()
    {
        delete m_base;
    }

    dereference_expression::dereference_expression(const source_position position,
            expression *base)
        : node(position), m_base(base)
    {
    }

    void dereference_expression::accept(parser_visitor *visitor)
    {
        visitor->visit(this);
    }

    expression& dereference_expression::base()
    {
        return *m_base;
    }

    dereference_expression *dereference_expression::is_dereference()
    {
        return this;
    }

    dereference_expression::~dereference_expression()
    {
        delete m_base;
    }

    binary_expression::binary_expression(const source_position position, expression *lhs,
            expression *rhs, const binary_operator operation)
        : node(position), m_lhs(lhs), m_rhs(rhs), m_operator(operation)
    {
    }

    void binary_expression::accept(parser_visitor *visitor)
    {
        visitor->visit(this);
    }

    binary_expression *binary_expression::is_binary()
    {
        return this;
    }

    expression& binary_expression::lhs()
    {
        return *m_lhs;
    }

    expression& binary_expression::rhs()
    {
        return *m_rhs;
    }

    binary_operator binary_expression::operation() const
    {
        return m_operator;
    }

    binary_expression::~binary_expression()
    {
        delete m_lhs;
        delete m_rhs;
    }

    unary_expression::unary_expression(const source_position position, expression *operand,
            const unary_operator operation)
        : node(position), m_operand(operand), m_operator(operation)
    {
    }

    void unary_expression::accept(parser_visitor *visitor)
    {
        visitor->visit(this);
    }

    unary_expression *unary_expression::is_unary()
    {
        return this;
    }

    expression& unary_expression::operand()
    {
        return *m_operand;
    }

    unary_operator unary_expression::operation() const
    {
        return this->m_operator;
    }

    unary_expression::~unary_expression()
    {
        delete m_operand;
    }

    procedure_call::procedure_call(const source_position position, designator_expression *callable,
            std::vector<expression *>&& arguments)
        : node(position), m_callable(callable), arguments(std::move(arguments))
    {
    }

    void procedure_call::accept(parser_visitor *visitor)
    {
        visitor->visit(this);
    }

    procedure_call *procedure_call::is_call_expression()
    {
        return this;
    }

    designator_expression& procedure_call::callable()
    {
        return *m_callable;
    }

    procedure_call::~procedure_call()
    {
        for (const expression *argument : arguments)
        {
            delete argument;
        }
        delete m_callable;
    }

    cast_expression::cast_expression(const source_position position, type_expression *target, expression *value)
        : node(position), m_target(target), m_value(value)
    {
    }

    void cast_expression::accept(parser_visitor *visitor)
    {
        visitor->visit(this);
    }

    cast_expression *cast_expression::is_cast()
    {
        return this;
    }

    type_expression& cast_expression::target()
    {
        return *m_target;
    }

    expression& cast_expression::value()
    {
        return *m_value;
    }

    cast_expression::~cast_expression()
    {
        delete m_target;
        delete m_value;
    }

    traits_expression::traits_expression(const source_position position, identifier&& name,
            std::vector<type_expression *>&& arguments)
        : node(position), arguments(std::move(arguments)), name(std::move(name))
    {
    }

    traits_expression::~traits_expression()
    {
        for (const type_expression *argument : this->arguments)
        {
            delete argument;
        }
    }

    void traits_expression::accept(parser_visitor *visitor)
    {
        visitor->visit(this);
    }

    traits_expression *traits_expression::is_traits()
    {
        return this;
    }

    conditional_statements::conditional_statements(expression *prerequisite, std::vector<statement *>&& statements)
        : m_prerequisite(prerequisite), statements(std::move(statements))
    {
    }

    expression& conditional_statements::prerequisite()
    {
        return *m_prerequisite;
    }

    conditional_statements::~conditional_statements()
    {
        delete m_prerequisite;
        for (auto *statement : statements)
        {
            delete statement;
        }
    }

    case_statement::case_statement(const source_position position,
            expression *condition, std::vector<switch_case>&& cases, std::vector<statement *> *alternative)
        : node(position), m_condition(condition), cases(std::move(cases)), alternative(alternative)
    {
    }

    void case_statement::accept(parser_visitor *visitor)
    {
        visitor->visit(this);
    }

    expression& case_statement::condition()
    {
        return *m_condition;
    }

    assign_statement::assign_statement(const source_position position, designator_expression *lvalue,
            expression *rvalue)
        : node(position), m_lvalue(lvalue), m_rvalue(rvalue)
    {
    }

    void assign_statement::accept(parser_visitor *visitor)
    {
        visitor->visit(this);
    }

    named_expression *designator_expression::is_named()
    {
        return nullptr;
    }

    array_access_expression *designator_expression::is_array_access()
    {
        return nullptr;
    }

    field_access_expression *designator_expression::is_field_access()
    {
        return nullptr;
    }

    dereference_expression *designator_expression::is_dereference()
    {
        return nullptr;
    }

    designator_expression& assign_statement::lvalue()
    {
        return *m_lvalue;
    }

    expression& assign_statement::rvalue()
    {
        return *m_rvalue;
    }

    assign_statement::~assign_statement()
    {
        delete m_rvalue;
    }

    if_statement::if_statement(const source_position position, conditional_statements *branch,
            std::vector<conditional_statements *>&& branches,
            std::vector<statement *> *alternative)
        : node(position), m_branch(branch), branches(std::move(branches)), alternative(alternative)
    {
    }

    void if_statement::accept(parser_visitor *visitor)
    {
        visitor->visit(this);
    }

    conditional_statements& if_statement::branch()
    {
        return *m_branch;
    }

    if_statement::~if_statement()
    {
        delete m_branch;
        for (const conditional_statements *branch : branches)
        {
            delete branch;
        }
        delete this->alternative;
    }

    import_declaration::import_declaration(const source_position position, std::vector<std::string>&& segments)
        : node(position), segments(std::move(segments))
    {
    }

    void import_declaration::accept(parser_visitor *visitor)
    {
        visitor->visit(this);
    }

    while_statement::while_statement(const source_position position, conditional_statements *branch,
            std::vector<conditional_statements *>&& branches)
        : node(position), m_branch(branch), branches(std::move(branches))
    {
    }

    void while_statement::accept(parser_visitor *visitor)
    {
        visitor->visit(this);
    }

    conditional_statements& while_statement::branch()
    {
        return *m_branch;
    }

    while_statement::~while_statement()
    {
        delete m_branch;
        for (const conditional_statements *branch : branches)
        {
            delete branch;
        }
    }

    const char *print_binary_operator(const binary_operator operation)
    {
        switch (operation)
        {
            using enum binary_operator;
            case sum:
                return "+";
            case subtraction: 
                return "-";
            case multiplication:
                return "*";
            case division:
                return "/";
            case remainder:
                return "%";
            case equals:
                return "=";
            case not_equals:
                return "<>";
            case less:
                return "<";
            case less_equal:
                return "<=";
            case greater:
                return ">";
            case greater_equal:
                return ">=";
            case conjunction:
                return "and";
            case disjunction:
                return "or";
            case exclusive_disjunction:
                return "xor";
            case shift_left:
                return "<<";
            case shift_right:
                return ">>";
        }
        __builtin_unreachable();
    };
}