tdlight/td/generate/tl_writer_cpp.cpp

699 lines
24 KiB
C++
Raw Normal View History

//
2022-12-31 22:28:08 +01:00
// Copyright Aliaksei Levin (levlam@telegram.org), Arseny Smirnov (arseny30@gmail.com) 2014-2023
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
#include "tl_writer_cpp.h"
#include <cassert>
namespace td {
std::string TD_TL_writer_cpp::gen_output_begin(const std::string &additional_imports) const {
std::string ext_include_str;
for (auto &it : ext_include) {
ext_include_str += "#include " + it + "\n";
}
if (!ext_include_str.empty()) {
ext_include_str += "\n";
}
return "#include \"" + tl_name + ".h\"\n\n" + ext_include_str +
"#include \"td/utils/common.h\"\n"
"#include \"td/utils/format.h\"\n"
"#include \"td/utils/logging.h\"\n"
"#include \"td/utils/SliceBuilder.h\"\n"
"#include \"td/utils/tl_parsers.h\"\n"
2021-11-01 18:02:24 +01:00
"#include \"td/utils/tl_storers.h\"\n"
"#include \"td/utils/TlStorerToString.h\"\n\n" +
additional_imports +
"namespace td {\n"
"namespace " +
tl_name + " {\n\n";
}
std::string TD_TL_writer_cpp::gen_output_begin_once() const {
return "std::string to_string(const BaseObject &value) {\n"
" TlStorerToString storer;\n"
" value.store(storer, \"\");\n"
" return storer.move_as_string();\n"
"}\n";
}
std::string TD_TL_writer_cpp::gen_output_end() const {
return "} // namespace " + tl_name +
"\n"
"} // namespace td\n";
}
std::string TD_TL_writer_cpp::gen_field_definition(const std::string &class_name, const std::string &type_name,
const std::string &field_name) const {
return "";
}
std::string TD_TL_writer_cpp::gen_vars(const tl::tl_combinator *t, const tl::tl_tree_type *result_type,
std::vector<tl::var_description> &vars) const {
for (std::size_t i = 0; i < vars.size(); i++) {
vars[i].index = static_cast<int>(i);
vars[i].is_stored = false;
vars[i].is_type = false;
vars[i].parameter_num = -1;
vars[i].function_arg_num = -1;
}
if (result_type != nullptr) {
assert(result_type->children.empty());
}
for (std::size_t i = 0; i < t->args.size(); i++) {
const tl::arg &a = t->args[i];
int arg_type = a.type->get_type();
if (arg_type == tl::NODE_TYPE_VAR_TYPE) {
const tl::tl_tree_var_type *var_type = static_cast<const tl::tl_tree_var_type *>(a.type);
assert(a.flags & tl::FLAG_EXCL);
assert(var_type->var_num < static_cast<int>(vars.size()));
assert(var_type->var_num >= 0);
assert(!vars[var_type->var_num].is_type);
vars[var_type->var_num].is_type = true;
vars[var_type->var_num].function_arg_num = static_cast<int>(i);
}
}
std::string res;
for (std::size_t i = 0; i < vars.size(); i++) {
if (!vars[i].is_type) {
assert(vars[i].parameter_num == -1);
assert(vars[i].function_arg_num == -1);
assert(vars[i].is_stored == false);
res += " " + gen_class_name("#") + " " + gen_var_name(vars[i]) + ";\n";
}
}
return res;
}
std::string TD_TL_writer_cpp::gen_function_vars(const tl::tl_combinator *t,
std::vector<tl::var_description> &vars) const {
for (std::size_t i = 0; i < vars.size(); i++) {
vars[i].index = static_cast<int>(i);
vars[i].is_stored = false;
vars[i].is_type = false;
vars[i].parameter_num = -1;
vars[i].function_arg_num = -1;
}
for (std::size_t i = 0; i < t->args.size(); i++) {
const tl::arg &a = t->args[i];
int arg_type = a.type->get_type();
if (arg_type == tl::NODE_TYPE_VAR_TYPE) {
const tl::tl_tree_var_type *var_type = static_cast<const tl::tl_tree_var_type *>(a.type);
assert(a.flags & tl::FLAG_EXCL);
assert(var_type->var_num >= 0);
assert(!vars[var_type->var_num].is_type);
vars[var_type->var_num].is_type = true;
vars[var_type->var_num].function_arg_num = static_cast<int>(i);
}
}
return "";
}
std::string TD_TL_writer_cpp::gen_uni(const tl::tl_tree_type *result_type, std::vector<tl::var_description> &vars,
bool check_negative) const {
assert(result_type->children.empty());
return "";
}
std::string TD_TL_writer_cpp::gen_constructor_id_store_raw(const std::string &id) const {
return "s.store_binary(" + id + ");";
}
std::string TD_TL_writer_cpp::gen_constructor_id_store(std::int32_t id, int storer_type) const {
if (storer_type == 1) {
return "";
}
return " " + gen_constructor_id_store_raw(int_to_string(id)) + "\n";
}
std::string TD_TL_writer_cpp::gen_fetch_class_name(const tl::tl_tree_type *tree_type) const {
const tl::tl_type *t = tree_type->type;
const std::string &name = t->name;
if (name == "#" || name == "Int32") {
return "TlFetchInt";
}
if (name == "Int53" || name == "Int64") {
return "TlFetchLong";
}
if (name == "True" || name == "Bool" || name == "Int" || name == "Long" || name == "Double" || name == "Int128" ||
name == "Int256") {
return "TlFetch" + name;
}
if (name == "String") {
return "TlFetchString<string>";
}
if (name == "Bytes") {
return "TlFetchBytes<bytes>";
}
if (name == "Vector") {
assert(t->arity == 1);
assert(tree_type->children.size() == 1);
assert(tree_type->children[0]->get_type() == tl::NODE_TYPE_TYPE);
const tl::tl_tree_type *child = static_cast<const tl::tl_tree_type *>(tree_type->children[0]);
return "TlFetchVector<" + gen_full_fetch_class_name(child) + ">";
}
assert(!is_built_in_simple_type(name) && !is_built_in_complex_type(name));
for (std::size_t i = 0; i < tree_type->children.size(); i++) {
assert(tree_type->children[i]->get_type() == tl::NODE_TYPE_NAT_CONST);
}
assert(tree_type->children.empty());
return "TlFetchObject<" + gen_main_class_name(t) + ">";
}
std::string TD_TL_writer_cpp::gen_full_fetch_class_name(const tl::tl_tree_type *tree_type) const {
const tl::tl_type *t = tree_type->type;
const std::string &name = t->name;
assert(!(t->flags & tl::FLAG_DEFAULT_CONSTRUCTOR)); // Not supported yet
std::int32_t expected_constructor_id = 0;
if (tree_type->flags & tl::FLAG_BARE) {
assert(is_type_bare(t));
} else {
if (is_type_bare(t)) {
for (std::size_t i = 0; i < t->constructors_num; i++) {
if (is_built_in_complex_type(name) || is_combinator_supported(t->constructors[i])) {
assert(expected_constructor_id == 0);
expected_constructor_id = t->constructors[i]->id;
assert(expected_constructor_id != 0);
}
}
}
}
if (expected_constructor_id == 0) {
return gen_fetch_class_name(tree_type);
}
return "TlFetchBoxed<" + gen_fetch_class_name(tree_type) + ", " + int_to_string(expected_constructor_id) + ">";
}
std::string TD_TL_writer_cpp::gen_type_fetch(const std::string &field_name, const tl::tl_tree_type *tree_type,
const std::vector<tl::var_description> &vars, int parser_type) const {
return gen_full_fetch_class_name(tree_type) + "::parse(p)";
}
std::string TD_TL_writer_cpp::gen_field_fetch(int field_num, const tl::arg &a, std::vector<tl::var_description> &vars,
bool flat, int parser_type) const {
assert(parser_type >= 0);
std::string field_name = (parser_type == 0 ? (field_num == 0 ? ": " : ", ") : "res->") + gen_field_name(a.name);
if (a.type->get_type() == tl::NODE_TYPE_VAR_TYPE) {
assert(parser_type == 1);
const tl::tl_tree_var_type *t = static_cast<const tl::tl_tree_var_type *>(a.type);
assert(a.flags == tl::FLAG_EXCL);
assert(a.var_num == -1);
assert(a.exist_var_num == -1);
assert(t->var_num >= 0);
assert(vars[t->var_num].is_type);
assert(!vars[t->var_num].is_stored);
vars[t->var_num].is_stored = true;
return " " + field_name + " = " + gen_base_function_class_name() + "::fetch(p);\n";
}
assert(!(a.flags & tl::FLAG_EXCL));
assert(!(a.flags & tl::FLAG_OPT_VAR));
std::string res = " ";
if (a.exist_var_num != -1) {
assert(0 <= a.exist_var_num && a.exist_var_num < static_cast<int>(vars.size()));
assert(vars[a.exist_var_num].is_stored);
res += "if (" + gen_var_name(vars[a.exist_var_num]) + " & " + int_to_string(1 << a.exist_var_bit) + ") { ";
}
if (flat) {
// TODO
// return gen_field_fetch(const tl::arg &a, std::vector<tl::var_description> &vars, int num, bool flat);
}
bool store_to_var_num = false;
if (a.var_num >= 0) {
assert(a.type->get_type() == tl::NODE_TYPE_TYPE);
assert(static_cast<const tl::tl_tree_type *>(a.type)->type->id == tl::ID_VAR_NUM);
assert(0 <= a.var_num && a.var_num < static_cast<int>(vars.size()));
if (!vars[a.var_num].is_stored) {
res += "if ((" + gen_var_name(vars[a.var_num]) + " = ";
store_to_var_num = true;
} else {
assert(false);
}
vars[a.var_num].is_stored = true;
}
res += field_name + (parser_type == 0 ? "(" : " = ");
assert(a.type->get_type() == tl::NODE_TYPE_TYPE);
const tl::tl_tree_type *tree_type = static_cast<tl::tl_tree_type *>(a.type);
res += gen_type_fetch(field_name, tree_type, vars, parser_type);
if (store_to_var_num) {
res += ") < 0) { FAIL(\"Variable of type # can't be negative\"); }";
} else {
res += (parser_type == 0 ? ")" : ";");
}
if (a.exist_var_num >= 0) {
res += " }";
if (store_to_var_num) {
res += " else { " + gen_var_name(vars[a.var_num]) + " = 0; }";
}
}
res += "\n";
return res;
}
std::string TD_TL_writer_cpp::gen_var_type_fetch(const tl::arg &a) const {
assert(false);
return "";
}
std::string TD_TL_writer_cpp::get_pretty_field_name(std::string field_name) const {
if (!field_name.empty() && field_name[0] == '_') {
return "";
}
auto equals_pos = field_name.find('=');
if (equals_pos != std::string::npos && equals_pos + 3 < field_name.size()) {
field_name = field_name.substr(equals_pos + 2);
if (field_name.back() == ')') {
field_name.pop_back();
}
}
while (!field_name.empty() && field_name.back() == '_') {
field_name.pop_back();
}
return field_name;
}
std::string TD_TL_writer_cpp::get_pretty_class_name(std::string class_name) const {
if (tl_name != "mtproto_api") {
for (std::size_t i = 0; i < class_name.size(); i++) {
if (class_name[i] == '_') {
class_name[i] = '.';
}
}
}
return class_name;
}
std::string TD_TL_writer_cpp::gen_vector_store(const std::string &field_name, const tl::tl_tree_type *t,
const std::vector<tl::var_description> &vars, int storer_type) const {
std::string num = !field_name.empty() && field_name[0] == '_' ? "2" : "";
return "{ s.store_vector_begin(\"" + get_pretty_field_name(field_name) + "\", " + field_name +
".size()); for (const auto &_value" + num + " : " + field_name + ") { " +
gen_type_store("_value" + num, t, vars, storer_type) + " } s.store_class_end(); }";
}
std::string TD_TL_writer_cpp::gen_store_class_name(const tl::tl_tree_type *tree_type) const {
const tl::tl_type *t = tree_type->type;
const std::string &name = t->name;
if (name == "#" || name == "Int" || name == "Long" || name == "Int32" || name == "Int53" || name == "Int64" ||
name == "Double" || name == "Int128" || name == "Int256") {
return "TlStoreBinary";
}
if (name == "Bool") {
return "TlStoreBool";
}
if (name == "True") {
2021-11-01 18:02:24 +01:00
assert(false);
return "";
}
if (name == "String" || name == "Bytes") {
return "TlStoreString";
}
if (name == "Vector") {
assert(t->arity == 1);
assert(tree_type->children.size() == 1);
assert(tree_type->children[0]->get_type() == tl::NODE_TYPE_TYPE);
const tl::tl_tree_type *child = static_cast<const tl::tl_tree_type *>(tree_type->children[0]);
return "TlStoreVector<" + gen_full_store_class_name(child) + ">";
}
assert(!is_built_in_simple_type(name) && !is_built_in_complex_type(name));
for (std::size_t i = 0; i < tree_type->children.size(); i++) {
assert(tree_type->children[i]->get_type() == tl::NODE_TYPE_NAT_CONST);
}
assert(tree_type->children.empty());
return "TlStoreObject";
}
std::string TD_TL_writer_cpp::gen_full_store_class_name(const tl::tl_tree_type *tree_type) const {
const tl::tl_type *t = tree_type->type;
assert(!(t->flags & tl::FLAG_DEFAULT_CONSTRUCTOR)); // Not supported yet
if ((tree_type->flags & tl::FLAG_BARE) != 0 || t->name == "#" || t->name == "Bool") {
return gen_store_class_name(tree_type);
}
if (is_built_in_complex_type(t->name)) {
return "TlStoreBoxed<" + gen_store_class_name(tree_type) + ", " + int_to_string(t->constructors[0]->id) + ">";
}
if (!is_type_bare(t)) {
return "TlStoreBoxedUnknown<" + gen_store_class_name(tree_type) + ">";
}
for (std::size_t i = 0; i < t->constructors_num; i++) {
if (is_combinator_supported(t->constructors[i])) {
return "TlStoreBoxed<" + gen_store_class_name(tree_type) + ", " + int_to_string(t->constructors[i]->id) + ">";
}
}
assert(false);
return "";
}
std::string TD_TL_writer_cpp::gen_type_store(const std::string &field_name, const tl::tl_tree_type *tree_type,
const std::vector<tl::var_description> &vars, int storer_type) const {
if (storer_type == 0) {
return gen_full_store_class_name(tree_type) + "::store(" + field_name + ", s);";
}
const tl::tl_type *t = tree_type->type;
const std::string &name = t->name;
assert(!(t->flags & tl::FLAG_DEFAULT_CONSTRUCTOR)); // Not supported yet
if (name == "#" || name == "Int" || name == "Long" || name == "Int32" || name == "Int53" || name == "Int64" ||
name == "Double" || name == "Bool" || name == "String" || name == "Int128" || name == "Int256") {
return "s.store_field(\"" + get_pretty_field_name(field_name) + "\", " + field_name + ");";
} else if (name == "True") {
// currently nothing to do
return "";
} else if (name == "Bytes") {
return "s.store_bytes_field(\"" + get_pretty_field_name(field_name) + "\", " + field_name + ");";
} else if (name == "Vector") {
const tl::tl_tree_type *child = static_cast<const tl::tl_tree_type *>(tree_type->children[0]);
return gen_vector_store(field_name, child, vars, storer_type);
} else {
assert(tree_type->children.empty());
return "s.store_object_field(\"" + get_pretty_field_name(field_name) + "\", static_cast<const BaseObject *>(" +
field_name + ".get()));";
}
}
std::string TD_TL_writer_cpp::gen_field_store(const tl::arg &a, std::vector<tl::var_description> &vars, bool flat,
int storer_type) const {
std::string field_name = gen_field_name(a.name);
std::string res = storer_type == 1 ? " " : " ";
if (a.type->get_type() == tl::NODE_TYPE_VAR_TYPE) {
const tl::tl_tree_var_type *t = static_cast<const tl::tl_tree_var_type *>(a.type);
assert(a.flags == tl::FLAG_EXCL);
assert(a.var_num == -1);
assert(a.exist_var_num == -1);
assert(t->var_num >= 0);
assert(!vars[t->var_num].is_stored);
vars[t->var_num].is_stored = true;
assert(vars[t->var_num].is_type);
return res + field_name + "->store(s);\n";
}
assert(!(a.flags & tl::FLAG_EXCL));
if (a.flags & tl::FLAG_OPT_VAR) {
assert(false);
assert(a.exist_var_num == -1);
assert(0 <= a.var_num && a.var_num < static_cast<int>(vars.size()));
assert(a.type->get_type() == tl::NODE_TYPE_TYPE);
assert(static_cast<const tl::tl_tree_type *>(a.type)->type->id == tl::ID_VAR_NUM);
assert(vars[a.var_num].is_stored);
assert(!vars[a.var_num].is_type);
return "";
}
2021-11-01 18:02:24 +01:00
if (a.exist_var_num >= 0 && a.var_num < 0 && a.type->get_type() == tl::NODE_TYPE_TYPE) {
const tl::tl_tree_type *tree_type = static_cast<tl::tl_tree_type *>(a.type);
if (tree_type->type->name == "True") {
return "";
}
}
if (a.exist_var_num >= 0) {
assert(a.exist_var_num < static_cast<int>(vars.size()));
assert(vars[a.exist_var_num].is_stored);
res += "if (" + gen_var_name(vars[a.exist_var_num]) + " & " + int_to_string(1 << a.exist_var_bit) + ") { ";
}
if (flat) {
// TODO
// return gen_field_store(const tl::arg &a, std::vector<tl::var_description> &vars, bool flat, int storer_type);
}
if (a.var_num >= 0) {
assert(a.type->get_type() == tl::NODE_TYPE_TYPE);
assert(static_cast<const tl::tl_tree_type *>(a.type)->type->id == tl::ID_VAR_NUM);
assert(a.var_num < static_cast<int>(vars.size()));
if (!vars[a.var_num].is_stored) {
field_name = "(" + gen_var_name(vars[a.var_num]) + " = " + field_name + ")";
vars[a.var_num].is_stored = true;
} else {
assert(false); // need to check value of stored var
field_name = gen_var_name(vars[a.var_num]);
}
}
assert(a.type->get_type() == tl::NODE_TYPE_TYPE);
const tl::tl_tree_type *tree_type = static_cast<tl::tl_tree_type *>(a.type);
res += gen_type_store(field_name, tree_type, vars, storer_type);
if (a.exist_var_num >= 0) {
res += " }";
}
res += "\n";
return res;
}
std::string TD_TL_writer_cpp::gen_forward_class_declaration(const std::string &class_name, bool is_proxy) const {
return "";
}
std::string TD_TL_writer_cpp::gen_class_begin(const std::string &class_name, const std::string &base_class_name,
bool is_proxy, const tl::tl_tree *result) const {
return "";
}
std::string TD_TL_writer_cpp::gen_class_end() const {
return "";
}
std::string TD_TL_writer_cpp::gen_class_alias(const std::string &class_name, const std::string &alias_name) const {
return "";
}
std::string TD_TL_writer_cpp::gen_get_id(const std::string &class_name, std::int32_t id, bool is_proxy) const {
if (is_proxy) {
return "";
}
return "\nconst std::int32_t " + class_name + "::ID;\n";
}
std::string TD_TL_writer_cpp::gen_function_result_type(const tl::tl_tree *result) const {
return "";
}
std::string TD_TL_writer_cpp::gen_fetch_function_begin(const std::string &parser_name, const std::string &class_name,
const std::string &parent_class_name, int arity, int field_count,
std::vector<tl::var_description> &vars, int parser_type) const {
for (std::size_t i = 0; i < vars.size(); i++) {
assert(vars[i].is_stored == false);
}
std::string fetched_type = "object_ptr<" + class_name + "> ";
std::string returned_type = "object_ptr<" + parent_class_name + "> ";
assert(arity == 0);
if (parser_type == 0) {
std::string result = "\n" + returned_type + class_name + "::fetch(" + parser_name +
" &p) {\n"
" return make_tl_object<" +
class_name + ">(";
if (field_count == 0) {
result += ");\n";
} else {
result +=
"p);\n"
"}\n\n" +
class_name + "::" + class_name + "(" + parser_name +
" &p)\n"
"#define FAIL(error) p.set_error(error)\n";
}
return result;
}
return "\n" + returned_type + class_name + "::fetch(" + parser_name +
" &p) {\n"
"#define FAIL(error) p.set_error(error); return nullptr;\n" +
(parser_type == -1 ? "" : " " + fetched_type + "res = make_tl_object<" + class_name + ">();\n");
}
std::string TD_TL_writer_cpp::gen_fetch_function_end(bool has_parent, int field_count,
const std::vector<tl::var_description> &vars,
int parser_type) const {
for (std::size_t i = 0; i < vars.size(); i++) {
assert(vars[i].is_stored);
}
if (parser_type == 0) {
if (field_count == 0) {
return "}\n";
}
return "#undef FAIL\n"
"{}\n";
}
if (parser_type == -1) {
return "#undef FAIL\n"
"}\n";
}
return " if (p.get_error()) { FAIL(\"\"); }\n"
" return " +
std::string(has_parent ? "std::move(res)" : "res") +
";\n"
"#undef FAIL\n"
"}\n";
}
std::string TD_TL_writer_cpp::gen_fetch_function_result_begin(const std::string &parser_name,
const std::string &class_name,
const tl::tl_tree *result) const {
return "\n" + class_name + "::ReturnType " + class_name + "::fetch_result(" + parser_name +
" &p) {\n"
"#define FAIL(error) p.set_error(error); return ReturnType()\n"
" return ";
}
std::string TD_TL_writer_cpp::gen_fetch_function_result_end() const {
return ";\n"
"#undef FAIL\n"
"}\n";
}
std::string TD_TL_writer_cpp::gen_fetch_function_result_any_begin(const std::string &parser_name,
const std::string &class_name, bool is_proxy) const {
return "";
}
std::string TD_TL_writer_cpp::gen_fetch_function_result_any_end(bool is_proxy) const {
return "";
}
std::string TD_TL_writer_cpp::gen_store_function_begin(const std::string &storer_name, const std::string &class_name,
int arity, std::vector<tl::var_description> &vars,
int storer_type) const {
for (std::size_t i = 0; i < vars.size(); i++) {
vars[i].is_stored = false;
}
if (storer_type == -1) {
return "";
}
assert(arity == 0);
return "\n"
"void " +
class_name + "::store(" + storer_name + " &s" +
std::string(storer_type <= 0 ? "" : ", const char *field_name") + ") const {\n" +
(storer_type <= 0 ? " (void)sizeof(s);\n"
: " if (!LOG_IS_STRIPPED(ERROR)) {\n"
" s.store_class_begin(field_name, \"" +
get_pretty_class_name(class_name) + "\");\n");
}
std::string TD_TL_writer_cpp::gen_store_function_end(const std::vector<tl::var_description> &vars,
int storer_type) const {
for (std::size_t i = 0; i < vars.size(); i++) {
assert(vars[i].is_stored);
}
if (storer_type == -1) {
return "";
}
return (storer_type <= 0 ? std::string()
: " s.store_class_end();\n"
" }\n") +
"}\n";
}
std::string TD_TL_writer_cpp::gen_fetch_switch_begin() const {
return " int constructor = p.fetch_int();\n"
" switch (constructor) {\n";
}
std::string TD_TL_writer_cpp::gen_fetch_switch_case(const tl::tl_combinator *t, int arity) const {
assert(arity == 0);
return " case " + gen_class_name(t->name) +
"::ID:\n"
" return " +
gen_class_name(t->name) + "::fetch(p);\n";
}
std::string TD_TL_writer_cpp::gen_fetch_switch_end() const {
return " default:\n"
" FAIL(PSTRING() << \"Unknown constructor found \" << format::as_hex(constructor));\n"
" }\n";
}
std::string TD_TL_writer_cpp::gen_constructor_begin(int field_count, const std::string &class_name,
bool is_default) const {
return "\n" + class_name + "::" + class_name + "(";
}
std::string TD_TL_writer_cpp::gen_constructor_field_init(int field_num, const std::string &class_name, const tl::arg &a,
bool is_default) const {
std::string field_type = gen_field_type(a);
if (field_type.empty()) {
return "";
}
std::string move_begin;
std::string move_end;
if ((field_type == "bytes" || field_type.compare(0, 5, "array") == 0 ||
field_type.compare(0, 10, "object_ptr") == 0) &&
!is_default) {
move_begin = "std::move(";
move_end = ")";
}
return (field_num == 0 ? ")\n : " : " , ") + gen_field_name(a.name) + "(" + move_begin +
(is_default ? "" : gen_field_name(a.name)) + move_end + ")\n";
}
std::string TD_TL_writer_cpp::gen_constructor_end(const tl::tl_combinator *t, int field_count, bool is_default) const {
if (field_count == 0) {
return ") {\n"
"}\n";
}
return "{}\n";
}
} // namespace td