1 files changed, 682 insertions, 484 deletions

diff --git a/server/src/xml.cppm b/server/src/xml.cppm
index 957f149..ff27c5c 100644
--- a/server/src/xml.cppm
+++ b/server/src/xml.cppm
@@ -23,610 +23,808 @@ static_assert(std::is_same_v<XML_Char, char>);
 
 namespace routemon::xml {
 
-  struct qname_view {
-    std::string_view ns_uri;
-    std::string_view local;
+struct qname_view
+{
+  std::string_view ns_uri;
+  std::string_view local;
 
-    auto operator==(qname_view const& rhs) const -> bool;
-  };
+  auto operator==(qname_view const& rhs) const -> bool;
+};
 
-  namespace detail {
+namespace detail {
 
-    constexpr auto qname_sep = '\xFF';
-    auto split_name(char const* name) noexcept -> qname_view {
-      auto [l, r] = util::split_on(name, qname_sep);
-      if (r) return { .ns_uri = l, .local = *r };
-      else return { .ns_uri = std::string_view{}, .local = l };
-    }
+constexpr auto qname_sep = '\xFF';
+auto split_name(char const* name) noexcept -> qname_view
+{
+  auto [l, r] = util::split_on(name, qname_sep);
+  if (r)
+    return {.ns_uri = l, .local = *r};
+  else
+    return {.ns_uri = std::string_view{}, .local = l};
+}
 
-  } // namespace detail
+} // namespace detail
 
-  class attribute_view_iterator {
-    std::string_view default_ns_uri_;
-    char const* const* attrs_;
+class attribute_view_iterator
+{
+  std::string_view default_ns_uri_;
+  char const* const* attrs_;
 
-    auto advance() -> void {
-      attrs_ += 2;
-    }
+  auto advance() -> void { attrs_ += 2; }
 
-  public:
-    using difference_type = std::ptrdiff_t;
-    using value_type = std::pair<qname_view, char const*>;
+public:
+  using difference_type = std::ptrdiff_t;
+  using value_type = std::pair<qname_view, char const*>;
 
-    struct sentinel {
-      friend constexpr auto operator==(attribute_view_iterator const& it, sentinel) noexcept -> bool {
-        return !*it.attrs_;
-      }
-    };
+  struct sentinel
+  {
+    friend constexpr auto
+    operator==(attribute_view_iterator const& it, sentinel) noexcept -> bool
+    {
+      return !*it.attrs_;
+    }
+  };
 
-    inline explicit attribute_view_iterator(std::string_view default_ns_uri, char const* const* attrs)
-      : default_ns_uri_{default_ns_uri}, attrs_{attrs}
-    {}
+  inline explicit attribute_view_iterator(
+      std::string_view default_ns_uri, char const* const* attrs)
+    : default_ns_uri_{default_ns_uri}, attrs_{attrs}
+  {
+  }
 
-    inline auto operator*() const -> std::pair<qname_view, char const*> {
-      if (!*attrs_)
-        throw std::runtime_error{"end of attribute list"};
-      auto qname = detail::split_name(attrs_[0]);
-      if (qname.ns_uri.empty())
-        qname.ns_uri = default_ns_uri_;
-      return std::make_pair(qname, attrs_[1]);
-    }
+  inline auto operator*() const -> std::pair<qname_view, char const*>
+  {
+    if (!*attrs_)
+      throw std::runtime_error{"end of attribute list"};
+    auto qname = detail::split_name(attrs_[0]);
+    if (qname.ns_uri.empty())
+      qname.ns_uri = default_ns_uri_;
+    return std::make_pair(qname, attrs_[1]);
+  }
 
-    // Pre-increment
-    inline auto operator++() -> attribute_view_iterator& {
-      advance();
-      return *this;
-    }
+  // Pre-increment
+  inline auto operator++() -> attribute_view_iterator&
+  {
+    advance();
+    return *this;
+  }
 
-    // Post-increment
-    inline auto operator++(int) -> attribute_view_iterator {
-      auto pre = *this;
-      advance();
-      return pre;
-    }
-  };
-  static_assert(std::input_iterator<attribute_view_iterator>);
+  // Post-increment
+  inline auto operator++(int) -> attribute_view_iterator
+  {
+    auto pre = *this;
+    advance();
+    return pre;
+  }
+};
+static_assert(std::input_iterator<attribute_view_iterator>);
 
-  class attribute_view : std::ranges::view_base {
-    std::string_view default_ns_uri_;
-    char const* const* attrs_;
+class attribute_view : std::ranges::view_base
+{
+  std::string_view default_ns_uri_;
+  char const* const* attrs_;
 
-  public:
-    inline explicit attribute_view(std::string_view default_ns_uri, char const** attrs)
-      : default_ns_uri_{default_ns_uri}, attrs_{const_cast<char const* const*>(attrs)}
-    {}
+public:
+  inline explicit attribute_view(
+      std::string_view default_ns_uri, char const** attrs)
+    : default_ns_uri_{default_ns_uri},
+      attrs_{const_cast<char const* const*>(attrs)}
+  {
+  }
 
-    [[nodiscard]] inline auto begin() const -> attribute_view_iterator {
-      return attribute_view_iterator{default_ns_uri_, attrs_};
-    }
+  [[nodiscard]] inline auto begin() const -> attribute_view_iterator
+  {
+    return attribute_view_iterator{default_ns_uri_, attrs_};
+  }
 
-    [[nodiscard]] inline auto end() const -> attribute_view_iterator::sentinel {
-      return {};
-    }
+  [[nodiscard]] inline auto end() const -> attribute_view_iterator::sentinel
+  {
+    return {};
+  }
 
-    inline auto lookup(qname_view want) -> std::optional<util::not_null<util::lazy_zstring_view>> {
-      for (auto const& [name, v] : *this) {
-        if (name == want) {
-          return util::not_null{util::lazy_zstring_view{v}};
-        }
+  inline auto lookup(qname_view want)
+      -> std::optional<util::not_null<util::lazy_zstring_view>>
+  {
+    for (auto const& [name, v] : *this)
+    {
+      if (name == want)
+      {
+        return util::not_null{util::lazy_zstring_view{v}};
       }
-      return std::nullopt;
     }
-  };
-  static_assert(std::ranges::input_range<attribute_view>);
+    return std::nullopt;
+  }
+};
+static_assert(std::ranges::input_range<attribute_view>);
 
-  template<class T> class promise;
+template <class T>
+class promise;
 
-  template<class T>
-  struct [[clang::coro_await_elidable, clang::coro_return_type]] parser {
-    using promise_type = promise<T>;
-    using result_type = promise_type::result_type;
-    using handle_type = std::coroutine_handle<promise_type>;
+template <class T>
+struct [[clang::coro_await_elidable, clang::coro_return_type]] parser
+{
+  using promise_type = promise<T>;
+  using result_type = promise_type::result_type;
+  using handle_type = std::coroutine_handle<promise_type>;
 
-  private:
-    handle_type h_;
+private:
+  handle_type h_;
 
-  public:
-    explicit parser(handle_type h)
-      : h_{h}
-    { assert(h); }
+public:
+  explicit parser(handle_type h) : h_{h} { assert(h); }
 
-    parser(const parser&) = delete;
-    parser(parser&& c) noexcept
-      : h_{std::exchange(c.h_, nullptr)}
-    {}
-    auto operator=(const parser&) -> parser& = delete;
-    auto operator=(parser&&) -> parser& = delete;
+  parser(const parser&) = delete;
+  parser(parser&& c) noexcept : h_{std::exchange(c.h_, nullptr)} {}
+  auto operator=(const parser&) -> parser& = delete;
+  auto operator=(parser&&) -> parser& = delete;
 
-    [[nodiscard]] auto promise() const -> promise_type& {
-      return h_.promise();
-    }
+  [[nodiscard]] auto promise() const -> promise_type& { return h_.promise(); }
 
-    ~parser() {
-      if (h_) h_.destroy();
-    }
-  };
+  ~parser()
+  {
+    if (h_)
+      h_.destroy();
+  }
+};
 
-  struct start_element_event {
-    qname_view name;
-    attribute_view attrs;
-  };
-  struct end_element_event {
-    qname_view name;
-  };
-  struct character_data_event {
-    std::string_view data;
-  };
-  struct processing_instructions_event {
-    util::lazy_zstring_view target;
-    util::lazy_zstring_view data;
-  };
-  struct xml_decl_event {
-    util::lazy_zstring_view version;
-    util::lazy_zstring_view encoding;
-    std::optional<bool> standalone;
-  };
-  struct eof_event {};
-  using event = std::variant<start_element_event,
-                             end_element_event,
-                             character_data_event,
-                             processing_instructions_event,
-                             xml_decl_event,
-                             eof_event>;
-  template<class T>
-  concept event_type = requires(event ev) { std::get<T>(ev); };
+struct start_element_event
+{
+  qname_view name;
+  attribute_view attrs;
+};
 
-  class executor;
-  using executor_ref = util::not_null<executor*>;
+struct end_element_event
+{
+  qname_view name;
+};
 
-  struct current_event_t {
-    executor_ref executor;
-  };
-  auto current_event(executor_ref executor) -> current_event_t {
-    return current_event_t{executor};
-  }
+struct character_data_event
+{
+  std::string_view data;
+};
 
-  class promise_base {
-    executor_ref executor_;
-    std::coroutine_handle<promise_base> continuation_ = nullptr;
+struct processing_instructions_event
+{
+  util::lazy_zstring_view target;
+  util::lazy_zstring_view data;
+};
 
-  public:
-    // Not having this constructor marked inline messes with coroutine
-    // HALO. (Hours 'wasted': many)
-    inline explicit promise_base(executor_ref executor)
-      : executor_{executor}
-    {}
+struct xml_decl_event
+{
+  util::lazy_zstring_view version;
+  util::lazy_zstring_view encoding;
+  std::optional<bool> standalone;
+};
 
-    [[nodiscard]] inline auto executor() const -> executor& {
-      return *executor_;
-    }
+struct eof_event
+{
+};
 
-    inline auto base_handle() -> std::coroutine_handle<promise_base> {
-      return std::coroutine_handle<promise_base>::from_promise(*this);
-    }
+using event = std::variant<
+    start_element_event, end_element_event, character_data_event,
+    processing_instructions_event, xml_decl_event, eof_event>;
 
-    [[nodiscard]] inline auto continuation() const -> std::coroutine_handle<promise_base> {
-      return continuation_;
-    }
-    inline auto set_continuation(std::coroutine_handle<promise_base> c) -> void {
-      continuation_ = c;
-    }
-  };
+template <class T>
+concept event_type = requires(event ev) { std::get<T>(ev); };
 
-  struct position {
-    std::size_t line;
-    std::size_t col;
-  };
+class executor;
+using executor_ref = util::not_null<executor*>;
 
-  class executor {
-    XML_Parser p_;
-    std::exception_ptr ex_ = nullptr;
-    std::coroutine_handle<promise_base> continuation_ = nullptr;
-    std::vector<std::optional<std::string>> default_namespace_;
-    std::unordered_map<std::string_view, std::vector<std::string>> namespaces_;
-    std::optional<event> ev_;
-    bool advance_ = true;
+struct current_event_t
+{
+  executor_ref executor;
+};
 
-    inline auto try_handle_event(event ev) noexcept -> void {
-      assert(!ex_);
+auto current_event(executor_ref executor) -> current_event_t
+{
+  return current_event_t{executor};
+}
 
-      try {
-        ev_ = std::move(ev);
-      } catch (...) {
-        ex_ = std::current_exception();
-        return;
-      }
-      advance_ = false;
-      if (!continuation_) {
-        // Parser returned (all subparsers are done) and has set the continuation to nullptr.
-        if (auto s = XML_StopParser(p_, /* resumable */ false); s != XML_STATUS_OK) {
-          ex_ = std::make_exception_ptr(std::runtime_error{"unexpected error when stopping XML parser"});
-          return;
-        }
-        ex_ = std::make_exception_ptr(std::runtime_error{"parser did not consume entire XML document"});
+class promise_base
+{
+  executor_ref executor_;
+  std::coroutine_handle<promise_base> continuation_ = nullptr;
+
+public:
+  // Not having this constructor marked inline messes with coroutine
+  // HALO. (Hours 'wasted': many)
+  inline explicit promise_base(executor_ref executor) : executor_{executor} {}
+
+  [[nodiscard]] inline auto executor() const -> executor& { return *executor_; }
+
+  inline auto base_handle() -> std::coroutine_handle<promise_base>
+  {
+    return std::coroutine_handle<promise_base>::from_promise(*this);
+  }
+
+  [[nodiscard]] inline auto continuation() const
+      -> std::coroutine_handle<promise_base>
+  {
+    return continuation_;
+  }
+  inline auto set_continuation(std::coroutine_handle<promise_base> c) -> void
+  {
+    continuation_ = c;
+  }
+};
+
+struct position
+{
+  std::size_t line;
+  std::size_t col;
+};
+
+class executor
+{
+  XML_Parser p_;
+  std::exception_ptr ex_ = nullptr;
+  std::coroutine_handle<promise_base> continuation_ = nullptr;
+  std::vector<std::optional<std::string>> default_namespace_;
+  std::unordered_map<std::string_view, std::vector<std::string>> namespaces_;
+  std::optional<event> ev_;
+  bool advance_ = true;
+
+  inline auto try_handle_event(event ev) noexcept -> void
+  {
+    assert(!ex_);
+
+    try
+    {
+      ev_ = std::move(ev);
+    }
+    catch (...)
+    {
+      ex_ = std::current_exception();
+      return;
+    }
+    advance_ = false;
+    if (!continuation_)
+    {
+      // Parser returned (all subparsers are done) and has set the
+      // continuation to nullptr.
+      if (auto s = XML_StopParser(p_, /* resumable */ false);
+          s != XML_STATUS_OK)
+      {
+        ex_ = std::make_exception_ptr(
+            std::runtime_error{"unexpected error when stopping XML parser"});
         return;
       }
-      continuation_.resume();
-      if (ex_) {
-        // Not sure if it's useful to report this error.
-        std::ignore = XML_StopParser(p_, /* resumable */ false);
-      }
+      ex_ = std::make_exception_ptr(
+          std::runtime_error{"parser did not consume entire XML document"});
+      return;
+    }
+    continuation_.resume();
+    if (ex_)
+    {
+      // Not sure if it's useful to report this error.
+      std::ignore = XML_StopParser(p_, /* resumable */ false);
     }
+  }
 
-    static auto handle_start_element(void* ctx, char const* name, char const** attrs) noexcept -> void {
-      auto qname = detail::split_name(name);
-      static_cast<executor*>(ctx)->try_handle_event(start_element_event{
-          .name = qname,
-          .attrs = attribute_view{qname.ns_uri, attrs},
+  static auto
+  handle_start_element(void* ctx, char const* name, char const** attrs) noexcept
+      -> void
+  {
+    auto qname = detail::split_name(name);
+    static_cast<executor*>(ctx)->try_handle_event(
+        start_element_event{
+            .name = qname,
+            .attrs = attribute_view{qname.ns_uri, attrs},
         });
-    }
-    static auto handle_end_element(void* ctx, char const* name) noexcept -> void {
-      static_cast<executor*>(ctx)->try_handle_event(end_element_event{
-          .name = detail::split_name(name),
+  }
+
+  static auto handle_end_element(void* ctx, char const* name) noexcept -> void
+  {
+    static_cast<executor*>(ctx)->try_handle_event(
+        end_element_event{
+            .name = detail::split_name(name),
         });
-    }
-    static auto handle_character_data(void* ctx, char const* s, int len) noexcept -> void {
-      static_cast<executor*>(ctx)->try_handle_event(character_data_event{
-          .data = std::string_view{s, static_cast<std::size_t>(len)},
+  }
+
+  static auto handle_character_data(void* ctx, char const* s, int len) noexcept
+      -> void
+  {
+    static_cast<executor*>(ctx)->try_handle_event(
+        character_data_event{
+            .data = std::string_view{s, static_cast<std::size_t>(len)},
         });
-    }
-    static auto handle_processing_instructions(void* ctx, char const* target, char const* data) noexcept -> void {
-      static_cast<executor*>(ctx)->try_handle_event(processing_instructions_event{
-          .target = util::lazy_zstring_view{target},
-          .data = util::lazy_zstring_view{data},
+  }
+
+  static auto handle_processing_instructions(
+      void* ctx, char const* target, char const* data) noexcept -> void
+  {
+    static_cast<executor*>(ctx)->try_handle_event(
+        processing_instructions_event{
+            .target = util::lazy_zstring_view{target},
+            .data = util::lazy_zstring_view{data},
         });
+  }
+
+  static auto handle_external_entity_ref(
+      XML_Parser, char const* /* context */, char const* /* base */,
+      char const* /* system_id */, char const* /* public_id */) noexcept -> int
+  {
+    return XML_STATUS_ERROR;
+  }
+
+  static auto handle_start_namespace_decl(
+      void* ctx, char const* prefix, char const* uri) noexcept -> void
+  {
+    if (prefix)
+    {
+      static_cast<executor*>(ctx)
+          ->namespaces_[std::string_view{prefix}]
+          .emplace_back(uri);
     }
-    static auto handle_external_entity_ref(XML_Parser, char const* /* context */, char const* /* base */, char const* /* system_id */, char const* /* public_id */) noexcept -> int {
-      return XML_STATUS_ERROR;
+    else
+    {
+      static_cast<executor*>(ctx)->default_namespace_.push_back(
+          uri ? std::make_optional<std::string>(uri) : std::nullopt);
     }
-    static auto handle_start_namespace_decl(void* ctx, char const* prefix, char const* uri) noexcept -> void {
-      if (prefix) {
-        static_cast<executor*>(ctx)->namespaces_[std::string_view{prefix}].emplace_back(uri);
-      } else {
-        static_cast<executor*>(ctx)->default_namespace_.push_back(uri ? std::make_optional<std::string>(uri) : std::nullopt);
-      }
+  }
+
+  static auto handle_end_namespace_decl(void* ctx, char const* prefix) noexcept
+      -> void
+  {
+    if (prefix)
+    {
+      static_cast<executor*>(ctx)
+          ->namespaces_[std::string_view{prefix}]
+          .pop_back();
     }
-    static auto handle_end_namespace_decl(void* ctx, char const* prefix) noexcept -> void {
-      if (prefix) {
-        static_cast<executor*>(ctx)->namespaces_[std::string_view{prefix}].pop_back();
-      } else {
-        static_cast<executor*>(ctx)->default_namespace_.pop_back();
-      }
+    else
+    {
+      static_cast<executor*>(ctx)->default_namespace_.pop_back();
     }
-    static auto handle_xml_decl(void * ctx, char const* version, char const* encoding, int standalone) noexcept -> void {
-      static_cast<executor*>(ctx)->try_handle_event(xml_decl_event{
-          .version = util::lazy_zstring_view{version},
-          .encoding = util::lazy_zstring_view{encoding},
-          .standalone = standalone < 0 ? std::nullopt : std::make_optional(standalone > 0),
+  }
+
+  static auto handle_xml_decl(
+      void* ctx, char const* version, char const* encoding,
+      int standalone) noexcept -> void
+  {
+    static_cast<executor*>(ctx)->try_handle_event(
+        xml_decl_event{
+            .version = util::lazy_zstring_view{version},
+            .encoding = util::lazy_zstring_view{encoding},
+            .standalone = standalone < 0 ? std::nullopt
+                                         : std::make_optional(standalone > 0),
         });
-    }
+  }
 
-    inline auto advance_flag() -> bool {
-      return advance_;
-    }
-    inline auto set_exception(std::exception_ptr ex) -> void {
-      ex_ = std::move(ex);
-    }
-    [[nodiscard]] inline auto take_exception() -> std::exception_ptr {
-      return std::exchange(ex_, nullptr);
-    }
+  inline auto advance_flag() -> bool { return advance_; }
 
-    template<class T> friend class promise;
+  inline auto set_exception(std::exception_ptr ex) -> void
+  {
+    ex_ = std::move(ex);
+  }
 
-  public:
-    executor();
+  [[nodiscard]] inline auto take_exception() -> std::exception_ptr
+  {
+    return std::exchange(ex_, nullptr);
+  }
 
-    executor(executor const&) = delete;
-    executor(executor&&) = delete;
-    auto operator=(executor const&) -> executor& = delete;
-    auto operator=(executor&&) -> executor& = delete;
+  template <class T>
+  friend class promise;
 
-    ~executor();
+public:
+  executor();
 
-    inline auto set_continuation(std::coroutine_handle<promise_base> c) -> void {
-      continuation_ = c;
-    }
-    inline auto set_advance_flag() -> void {
-      if (!ev_ || !std::holds_alternative<eof_event>(ev_.value())) {
-        advance_ = true;
-      }
-    }
-    inline auto event() const -> std::optional<event> const& {
-      return ev_;
-    }
-    inline auto resolve_namespace(std::string_view prefix) -> std::optional<std::string_view> {
-      if (auto it = namespaces_.find(prefix); it != namespaces_.end() && !it->second.empty())
-        return it->second.back();
-      return std::nullopt;
+  executor(executor const&) = delete;
+  executor(executor&&) = delete;
+  auto operator=(executor const&) -> executor& = delete;
+  auto operator=(executor&&) -> executor& = delete;
+
+  ~executor();
+
+  inline auto set_continuation(std::coroutine_handle<promise_base> c) -> void
+  {
+    continuation_ = c;
+  }
+
+  inline auto set_advance_flag() -> void
+  {
+    if (!ev_ || !std::holds_alternative<eof_event>(ev_.value()))
+    {
+      advance_ = true;
     }
-    [[nodiscard]] inline auto position() -> position {
-      return {
+  }
+
+  inline auto event() const -> std::optional<event> const& { return ev_; }
+
+  inline auto resolve_namespace(std::string_view prefix)
+      -> std::optional<std::string_view>
+  {
+    if (auto it = namespaces_.find(prefix);
+        it != namespaces_.end() && !it->second.empty())
+      return it->second.back();
+    return std::nullopt;
+  }
+
+  [[nodiscard]] inline auto position() -> position
+  {
+    return {
         .line = XML_GetCurrentLineNumber(p_),
         .col = XML_GetCurrentColumnNumber(p_),
-      };
-    }
+    };
+  }
 
-    auto start() -> void;
-    auto read(std::string_view xml, bool is_final) -> void;
-    auto end() -> void;
-  };
+  auto start() -> void;
+  auto read(std::string_view xml, bool is_final) -> void;
+  auto end() -> void;
+};
 
-  template<class T>
-  class promise_returnable : public promise_base {
-    std::optional<T> returned_value_;
+template <class T>
+class promise_returnable : public promise_base
+{
+  std::optional<T> returned_value_;
 
-  public:
-    using result_type = T;
-    using promise_base::promise_base;
+public:
+  using result_type = T;
+  using promise_base::promise_base;
 
-    template<class U>
-    auto return_value(U&& v) -> void {
-      returned_value_.emplace(std::forward<U>(v));
-    }
-    auto returned_value() -> T&& {
-      if (!returned_value_)
-        throw std::runtime_error{"XML coroutine did not return"};
-      return std::forward<T>(returned_value_.value());
-    }
-  };
+  template <class U>
+  auto return_value(U&& v) -> void
+  {
+    returned_value_.emplace(std::forward<U>(v));
+  }
 
-  template<>
-  class promise_returnable<void> : public promise_base {
-  public:
-    using result_type = void;
-    using promise_base::promise_base;
+  auto returned_value() -> T&&
+  {
+    if (!returned_value_)
+      throw std::runtime_error{"XML coroutine did not return"};
+    return std::forward<T>(returned_value_.value());
+  }
+};
 
-    auto return_void() -> void {}
-  };
+template <>
+class promise_returnable<void> : public promise_base
+{
+public:
+  using result_type = void;
+  using promise_base::promise_base;
 
-  template<class T>
-  class promise : public promise_returnable<T> {
-  public:
-    // Called with all the coroutine's arguments.
-    // Ignoring all but the first argument, which should be the executor.
-    template<class... Args>
-    explicit promise(executor_ref executor, Args&&...)
-      : promise_returnable<T>{executor}
-    {}
+  auto return_void() -> void {}
+};
 
-    auto handle() -> std::coroutine_handle<promise<T>> {
-      return {parser<T>::handle_type::from_promise(*this)};
-    }
+template <class T>
+class promise : public promise_returnable<T>
+{
+public:
+  // Called with all the coroutine's arguments.
+  // Ignoring all but the first argument, which should be the executor.
+  template <class... Args>
+  explicit promise(executor_ref executor, Args&&...)
+    : promise_returnable<T>{executor}
+  {
+  }
 
-    auto get_return_object() -> parser<T> {
-      return parser<T>{handle()};
-    }
+  auto handle() -> std::coroutine_handle<promise<T>>
+  {
+    return {parser<T>::handle_type::from_promise(*this)};
+  }
 
-    auto initial_suspend() {
-      return std::suspend_always{};
-    }
-    auto final_suspend() noexcept {
-      struct awaiter {
-        std::coroutine_handle<> h_;
+  auto get_return_object() -> parser<T> { return parser<T>{handle()}; }
+
+  auto initial_suspend() { return std::suspend_always{}; }
 
-        [[nodiscard]] constexpr auto await_ready() const noexcept -> bool { return false; }
-        auto await_suspend(std::coroutine_handle<>) -> std::coroutine_handle<> { return h_; }
-        constexpr auto await_resume() const noexcept -> void { return; }
-      };
-      if (this->continuation()) {
-        return awaiter{this->continuation()};
-      } else {
-        this->executor().set_continuation(nullptr);
-        return awaiter{std::noop_coroutine()};
+  auto final_suspend() noexcept
+  {
+    struct awaiter
+    {
+      std::coroutine_handle<> h_;
+
+      [[nodiscard]] constexpr auto await_ready() const noexcept -> bool
+      {
+        return false;
       }
+      auto await_suspend(std::coroutine_handle<>) -> std::coroutine_handle<>
+      {
+        return h_;
+      }
+      constexpr auto await_resume() const noexcept -> void { return; }
+    };
+    if (this->continuation())
+    {
+      return awaiter{this->continuation()};
     }
-
-    auto unhandled_exception() -> void {
-      this->executor().set_exception(std::current_exception());
+    else
+    {
+      this->executor().set_continuation(nullptr);
+      return awaiter{std::noop_coroutine()};
     }
+  }
 
-    auto await_transform(current_event_t const& req) {
-      struct awaiter {
-        executor_ref executor_;
+  auto unhandled_exception() -> void
+  {
+    this->executor().set_exception(std::current_exception());
+  }
 
-        [[nodiscard]] constexpr auto await_ready() const noexcept -> bool {
-          return !executor_->advance_flag();
-        }
-        auto await_suspend(std::coroutine_handle<promise<T>> h) -> void {
-          executor_->set_continuation(h.promise().base_handle());
-        }
-        [[nodiscard]] auto await_resume() const -> event {
-          assert(executor_->event());
-          return executor_->event().value();
-        }
-      };
-      return awaiter{req.executor};
-    }
+  auto await_transform(current_event_t const& req)
+  {
+    struct awaiter
+    {
+      executor_ref executor_;
 
-    template<class U>
-    auto await_transform(parser<U> const& coro) {
-      struct [[clang::coro_await_elidable]] awaiter {
-        util::not_null<promise<U>*> next_;
+      [[nodiscard]] constexpr auto await_ready() const noexcept -> bool
+      {
+        return !executor_->advance_flag();
+      }
+      auto await_suspend(std::coroutine_handle<promise<T>> h) -> void
+      {
+        executor_->set_continuation(h.promise().base_handle());
+      }
+      [[nodiscard]] auto await_resume() const -> event
+      {
+        assert(executor_->event());
+        return executor_->event().value();
+      }
+    };
+    return awaiter{req.executor};
+  }
+
+  template <class U>
+  auto await_transform(parser<U> const& coro)
+  {
+    struct [[clang::coro_await_elidable]] awaiter
+    {
+      util::not_null<promise<U>*> next_;
 
-        [[nodiscard]] constexpr auto await_ready() const noexcept -> bool { return false; }
-        auto await_suspend(std::coroutine_handle<promise<T>> h) -> std::coroutine_handle<> {
-          // Passed coroutine handle will be the same as parser<T>::handle_type::from_promise(*this)
-          next_->set_continuation(h.promise().base_handle());
-          return next_->handle();
+      [[nodiscard]] constexpr auto await_ready() const noexcept -> bool
+      {
+        return false;
+      }
+      auto await_suspend(std::coroutine_handle<promise<T>> h)
+          -> std::coroutine_handle<>
+      {
+        // Passed coroutine handle will be the same as
+        // parser<T>::handle_type::from_promise(*this)
+        next_->set_continuation(h.promise().base_handle());
+        return next_->handle();
+      }
+      auto await_resume() -> U
+      {
+        // Promise is still valid since coroutine frame is still alive
+        // (and suspended): control was transferred back to this
+        // coroutine via symmetric transfer in final_suspend(). Assuming
+        // that the destructor for coro still needs to run.
+        if (auto ex = next_->executor().take_exception())
+        {
+          std::rethrow_exception(ex);
         }
-        auto await_resume() -> U {
-          // Promise is still valid since coroutine frame is still alive (and suspended):
-          // control was transferred back to this coroutine via symmetric transfer in
-          // final_suspend(). Assuming that the destructor for coro still needs to run.
-          if (auto ex = next_->executor().take_exception()) {
-            std::rethrow_exception(ex);
-          } else {
-            if constexpr (!std::is_void_v<U>) {
-              return std::move(next_->returned_value());
-            }
+        else
+        {
+          if constexpr (!std::is_void_v<U>)
+          {
+            return std::move(next_->returned_value());
           }
         }
-      };
-      return awaiter{util::not_null{&coro.promise()}};
-    }
-  };
+      }
+    };
+    return awaiter{util::not_null{&coro.promise()}};
+  }
+};
 
-  // Helpers for handling XML documents. Non-polymorphic functions
-  // should be marked inline to allow HALO across TU boundaries.
+// Helpers for handling XML documents. Non-polymorphic functions
+// should be marked inline to allow HALO across TU boundaries.
 
-  template<class T>
-  concept unconstrained = true;
+template <class T>
+concept unconstrained = true;
 
-  template<class T, template<class U> concept C>
-  concept parser_of = requires {
-    typename T::result_type;
-    requires std::same_as<parser<typename T::result_type>, T>;
-      requires C<typename T::result_type>;
-  };
+template <class T, template <class U> concept C>
+concept parser_of = requires {
+  typename T::result_type;
+  requires std::same_as<parser<typename T::result_type>, T>;
+  requires C<typename T::result_type>;
+};
 
-  template<parser_of<unconstrained> T>
-  using parser_result_t = T::result_type;
+template <parser_of<unconstrained> T>
+using parser_result_t = T::result_type;
 
-  template<class T, class... Args>
-  concept parser_invocable = std::invocable<T, Args...> && parser_of<std::invoke_result_t<T, Args...>, unconstrained>;
+template <class T, class... Args>
+concept parser_invocable =
+    std::invocable<T, Args...>
+    && parser_of<std::invoke_result_t<T, Args...>, unconstrained>;
 
-  template<class Fn, class... Args>
+template <class Fn, class... Args>
   requires parser_invocable<Fn, Args...>
-  using parser_invoke_result_t = parser_result_t<std::invoke_result_t<Fn, Args...>>;
+using parser_invoke_result_t =
+    parser_result_t<std::invoke_result_t<Fn, Args...>>;
 
-  template<event_type T> auto expect_event(executor_ref e) -> parser<T> {
-    auto ev = co_await current_event(e);
-    if (!std::holds_alternative<T>(ev)) {
-      auto pos = e->position();
-      throw std::runtime_error{std::format("at {}:{}: unexpected event type, have {}", pos.line, pos.col, ev.index())};
-    }
-    e->set_advance_flag();
-    co_return std::get<T>(ev);
+template <event_type T>
+auto expect_event(executor_ref e) -> parser<T>
+{
+  auto ev = co_await current_event(e);
+  if (!std::holds_alternative<T>(ev))
+  {
+    auto pos = e->position();
+    throw std::runtime_error{std::format(
+        "at {}:{}: unexpected event type, have {}", pos.line, pos.col,
+        ev.index())};
   }
+  e->set_advance_flag();
+  co_return std::get<T>(ev);
+}
 
-  inline auto expect_start_element(executor_ref e, qname_view want) -> parser<attribute_view> {
-    auto ev = co_await expect_event<start_element_event>(e);
-    if (ev.name != want) {
-      auto pos = e->position();
-      throw std::runtime_error{std::format("at {}:{}: unexpected element started", pos.line, pos.col)};
-    }
-    co_return ev.attrs;
+inline auto expect_start_element(executor_ref e, qname_view want)
+    -> parser<attribute_view>
+{
+  auto ev = co_await expect_event<start_element_event>(e);
+  if (ev.name != want)
+  {
+    auto pos = e->position();
+    throw std::runtime_error{std::format(
+        "at {}:{}: unexpected element started", pos.line, pos.col)};
   }
+  co_return ev.attrs;
+}
 
-  inline auto allow_start_element(executor_ref e, qname_view want) -> parser<std::optional<attribute_view>> {
-    auto ev = co_await current_event(e);
-    if (auto const* pev = std::get_if<start_element_event>(&ev)) {
-      if (pev->name == want) {
-        e->set_advance_flag();
-        co_return pev->attrs;
-      }
+inline auto allow_start_element(executor_ref e, qname_view want)
+    -> parser<std::optional<attribute_view>>
+{
+  auto ev = co_await current_event(e);
+  if (auto const* pev = std::get_if<start_element_event>(&ev))
+  {
+    if (pev->name == want)
+    {
+      e->set_advance_flag();
+      co_return pev->attrs;
     }
-    co_return std::nullopt;
   }
+  co_return std::nullopt;
+}
 
-  inline auto expect_end_element(executor_ref e, qname_view want) -> parser<void> {
-    auto ev = co_await expect_event<end_element_event>(e);
-    if (ev.name != want) {
-      throw std::runtime_error{"unexpected element ended"};
-    }
+inline auto expect_end_element(executor_ref e, qname_view want) -> parser<void>
+{
+  auto ev = co_await expect_event<end_element_event>(e);
+  if (ev.name != want)
+  {
+    throw std::runtime_error{"unexpected element ended"};
   }
+}
 
-  inline auto ignore_whitespace(executor_ref e) -> parser<void> {
-    auto all_whitespace = [](std::string_view s) -> bool {
-      for (auto c : s)
-        if (c != ' ' && c != '\r' && c != '\n' && c != '\t')
-          return false;
-      return true;
-    };
+inline auto ignore_whitespace(executor_ref e) -> parser<void>
+{
+  auto all_whitespace = [](std::string_view s) -> bool
+  {
+    for (auto c : s)
+      if (c != ' ' && c != '\r' && c != '\n' && c != '\t')
+        return false;
+    return true;
+  };
 
-    while (true) {
-      auto ev = co_await current_event(e);
-      if (auto const* pev = std::get_if<character_data_event>(&ev); pev && all_whitespace(pev->data)) {
-        e->set_advance_flag();
-      } else {
-        co_return;
-      }
+  while (true)
+  {
+    auto ev = co_await current_event(e);
+    if (auto const* pev = std::get_if<character_data_event>(&ev);
+        pev && all_whitespace(pev->data))
+    {
+      e->set_advance_flag();
+    }
+    else
+    {
+      co_return;
     }
   }
+}
 
-  auto expect_element(executor_ref e, qname_view want, parser_invocable<executor_ref, attribute_view> auto p)
+auto expect_element(
+    executor_ref e, qname_view want,
+    parser_invocable<executor_ref, attribute_view> auto p)
     -> parser<parser_invoke_result_t<decltype(p), executor_ref, attribute_view>>
+{
+  co_await ignore_whitespace(e);
+  auto attrs = co_await expect_start_element(e, want);
+  auto&& res = co_await p(e, attrs);
+  co_await expect_end_element(e, want);
+  co_await ignore_whitespace(e);
+  co_return std::forward<
+      parser_invoke_result_t<decltype(p), executor_ref, attribute_view>>(res);
+}
+
+auto allow_element(
+    executor_ref e, qname_view want,
+    parser_invocable<executor_ref, attribute_view> auto p)
+    -> parser<std::optional<
+        parser_invoke_result_t<decltype(p), executor_ref, attribute_view>>>
+{
+  co_await ignore_whitespace(e);
+  if (auto mattrs = co_await allow_start_element(e, want))
   {
-    co_await ignore_whitespace(e);
-    auto attrs = co_await expect_start_element(e, want);
-    auto&& res = co_await p(e, attrs);
+    auto&& res = co_await p(e, *mattrs);
     co_await expect_end_element(e, want);
     co_await ignore_whitespace(e);
-    co_return std::forward<parser_invoke_result_t<decltype(p), executor_ref, attribute_view>>(res);
+    co_return std::make_optional(
+        std::forward<
+            parser_invoke_result_t<decltype(p), executor_ref, attribute_view>>(
+            res));
   }
+  co_return std::nullopt;
+}
 
-  auto allow_element(executor_ref e, qname_view want, parser_invocable<executor_ref, attribute_view> auto p)
-    -> parser<std::optional<parser_invoke_result_t<decltype(p), executor_ref, attribute_view>>>
+auto allow_element(
+    executor_ref e, qname_view want,
+    parser_invocable<executor_ref, attribute_view> auto p) -> parser<bool>
+  requires std::is_void_v<
+      parser_invoke_result_t<decltype(p), executor_ref, attribute_view>>
+{
+  co_await ignore_whitespace(e);
+  if (auto mattrs = co_await allow_start_element(e, want))
   {
+    co_await p(e, *mattrs);
+    co_await expect_end_element(e, want);
     co_await ignore_whitespace(e);
-    if (auto mattrs = co_await allow_start_element(e, want)) {
-      auto&& res = co_await p(e, *mattrs);
-      co_await expect_end_element(e, want);
-      co_await ignore_whitespace(e);
-      co_return std::make_optional(std::forward<parser_invoke_result_t<decltype(p), executor_ref, attribute_view>>(res));
-    }
-    co_return std::nullopt;
+    co_return true;
   }
+  co_return false;
+}
 
-  auto allow_element(executor_ref e, qname_view want, parser_invocable<executor_ref, attribute_view> auto p)
-    -> parser<bool>
-    requires std::is_void_v<parser_invoke_result_t<decltype(p), executor_ref, attribute_view>>
+inline auto
+ignore_contents(executor_ref e, std::optional<qname_view> muntil = std::nullopt)
+    -> parser<void>
+{
+  std::size_t depth = 0;
+  while (true)
   {
-    co_await ignore_whitespace(e);
-    if (auto mattrs = co_await allow_start_element(e, want)) {
-      co_await p(e, *mattrs);
-      co_await expect_end_element(e, want);
-      co_await ignore_whitespace(e);
-      co_return true;
+    auto ev = co_await current_event(e);
+    if (auto* pev = std::get_if<start_element_event>(&ev))
+    {
+      if (depth == 0 && muntil && pev->name == *muntil)
+      {
+        co_return;
+      }
+      else
+      {
+        depth++;
+      }
     }
-    co_return false;
-  }
-
-  inline auto ignore_contents(executor_ref e, std::optional<qname_view> muntil = std::nullopt) -> parser<void> {
-    std::size_t depth = 0;
-    while (true) {
-      auto ev = co_await current_event(e);
-      if (auto* pev = std::get_if<start_element_event>(&ev)) {
-        if (depth == 0 && muntil && pev->name == *muntil) {
-          co_return;
-        } else {
-          depth++;
-        }
-      } else if (std::holds_alternative<end_element_event>(ev)) {
-        if (depth == 0) {
-          co_return;
-        } else {
-          depth--;
-        }
+    else if (std::holds_alternative<end_element_event>(ev))
+    {
+      if (depth == 0)
+      {
+        co_return;
+      }
+      else
+      {
+        depth--;
       }
-      e->set_advance_flag();
     }
+    e->set_advance_flag();
   }
-  inline auto ignore_element_contents(executor_ref e, attribute_view) -> parser<void> {
-    co_await ignore_contents(e);
-  }
+}
+inline auto ignore_element_contents(executor_ref e, attribute_view)
+    -> parser<void>
+{
+  co_await ignore_contents(e);
+}
 
-  inline auto read_string(executor_ref e) -> parser<std::string> {
-    std::string s;
-    while (true) {
-      auto ev = co_await current_event(e);
-      if (auto* pev = std::get_if<character_data_event>(&ev)) {
-        e->set_advance_flag();
-        s += pev->data;
-      } else {
-        co_return s;
-      }
+inline auto read_string(executor_ref e) -> parser<std::string>
+{
+  std::string s;
+  while (true)
+  {
+    auto ev = co_await current_event(e);
+    if (auto* pev = std::get_if<character_data_event>(&ev))
+    {
+      e->set_advance_flag();
+      s += pev->data;
+    }
+    else
+    {
+      co_return s;
     }
   }
-  inline auto read_string_contents(executor_ref e, attribute_view) -> parser<std::string> {
-    co_return co_await read_string(e);
-  }
+}
+inline auto read_string_contents(executor_ref e, attribute_view)
+    -> parser<std::string>
+{
+  co_return co_await read_string(e);
+}
 
-  template<auto f>
-  auto hohalo() {
-    return []<class... Args>(Args&&... args) -> std::invoke_result_t<decltype(f), Args...> {
-      co_return co_await f(std::forward<Args>(args)...);
-    };
-  }
+template <auto f>
+auto hohalo()
+{
+  return []<class... Args>(
+             Args&&... args) -> std::invoke_result_t<decltype(f), Args...>
+  { co_return co_await f(std::forward<Args>(args)...); };
+}
 
 } // namespace routemon::xml