Remove variant and clean up

src/clang_complete.cc

@@ -656,18 +656,18 @@ ClangCompleteManager::ClangCompleteManager(Project* project,
       on_dropped_(on_dropped),
       preloaded_sessions_(kMaxPreloadedSessions),
       completion_sessions_(kMaxCompletionSessions) {
-  new std::thread([&]() {
+  std::thread([&]() {
     SetThreadName("comp-query");
     CompletionQueryMain(this);
-  });
-  new std::thread([&]() {
+  }).detach();
+  std::thread([&]() {
     SetThreadName("comp-preload");
     CompletionPreloadMain(this);
-  });
-  new std::thread([&]() {
+  }).detach();
+  std::thread([&]() {
     SetThreadName("diag-query");
     DiagnosticQueryMain(this);
-  });
+  }).detach();
 }
 
 void ClangCompleteManager::CodeComplete(
@@ -680,7 +680,6 @@ void ClangCompleteManager::CodeComplete(
 }
 
 void ClangCompleteManager::DiagnosticsUpdate(
-    const lsRequestId& id,
     const lsTextDocumentIdentifier& document) {
   bool has = false;
   diagnostic_request_.Iterate([&](const DiagnosticRequest& request) {

src/clang_complete.h

@@ -91,8 +91,7 @@ struct ClangCompleteManager {
                     const lsTextDocumentPositionParams& completion_location,
                     const OnComplete& on_complete);
   // Request a diagnostics update.
-  void DiagnosticsUpdate(const lsRequestId& request_id,
-                         const lsTextDocumentIdentifier& document);
+  void DiagnosticsUpdate(const lsTextDocumentIdentifier& document);
 
   // Notify the completion manager that |filename| has been viewed and we
   // should begin preloading completion data.

src/command_line.cc

@@ -172,7 +172,7 @@ void RunQueryDbThread(const std::string& bin_name,
                                       args);
       },
       [](lsRequestId id) {
-        if (!std::holds_alternative<std::monostate>(id)) {
+        if (id.Valid()) {
           Out_Error out;
           out.id = id;
           out.error.code = lsErrorCodes::InternalError;
@@ -243,7 +243,7 @@ void RunQueryDbThread(const std::string& bin_name,
 //
 // |ipc| is connected to a server.
 void LaunchStdinLoop(std::unordered_map<MethodType, Timer>* request_times) {
-  new std::thread([request_times]() {
+  std::thread([request_times]() {
     SetThreadName("stdin");
     auto* queue = QueueManager::instance();
     while (true) {
@@ -257,7 +257,7 @@ void LaunchStdinLoop(std::unordered_map<MethodType, Timer>* request_times) {
         // Emit an error ResponseMessage if |id| is available.
         if (message) {
           lsRequestId id = message->GetRequestId();
-          if (!std::holds_alternative<std::monostate>(id)) {
+          if (id.Valid()) {
             Out_Error out;
             out.id = id;
             out.error.code = lsErrorCodes::InvalidParams;
@@ -279,12 +279,12 @@ void LaunchStdinLoop(std::unordered_map<MethodType, Timer>* request_times) {
       if (method_type == kMethodType_Exit)
         break;
     }
-  });
+  }).detach();
 }
 
 void LaunchStdoutThread(std::unordered_map<MethodType, Timer>* request_times,
                         MultiQueueWaiter* waiter) {
-  new std::thread([=]() {
+  std::thread([=]() {
     SetThreadName("stdout");
     auto* queue = QueueManager::instance();
 
@@ -305,7 +305,7 @@ void LaunchStdoutThread(std::unordered_map<MethodType, Timer>* request_times,
         fflush(stdout);
       }
     }
-  });
+  }).detach();
 }
 
 void LanguageServerMain(const std::string& bin_name,

src/import_pipeline.cc

@@ -393,8 +393,7 @@ void ParseFile(DiagnosticsEngine* diag_engine,
                                 file_contents, &perf);
 
   if (indexes.empty()) {
-    if (g_config->index.enabled &&
-        !std::holds_alternative<std::monostate>(request.id)) {
+    if (g_config->index.enabled && request.id.Valid()) {
       Out_Error out;
       out.id = request.id;
       out.error.code = lsErrorCodes::InternalError;

src/include_complete.cc

@@ -29,21 +29,16 @@ std::string ElideLongPath(const std::string& path) {
 
 size_t TrimCommonPathPrefix(const std::string& result,
                             const std::string& trimmer) {
-  size_t i = 0;
-  while (i < result.size() && i < trimmer.size()) {
-    char a = result[i];
-    char b = trimmer[i];
-#if defined(_WIN32)
-    a = (char)tolower(a);
-    b = (char)tolower(b);
+#ifdef _WIN32
+  std::string s = result, t = trimmer;
+  std::transform(s.begin(), s.end(), s.begin(), ::tolower);
+  std::transform(t.begin(), t.end(), t.begin(), ::tolower);
+  if (s.compare(0, t.size(), t) == 0)
+    return t.size();
+#else
+  if (result.compare(0, trimmer.size(), trimmer) == 0)
+    return trimmer.size();
 #endif
-    if (a != b)
-      break;
-    ++i;
-  }
-
-  if (i == trimmer.size())
-    return i;
   return 0;
 }
 
@@ -51,21 +46,14 @@ size_t TrimCommonPathPrefix(const std::string& result,
 bool TrimPath(Project* project,
               const std::string& project_root,
               std::string* insert_path) {
-  size_t start = 0;
+  size_t start = TrimCommonPathPrefix(*insert_path, project_root);
   bool angle = false;
 
-  size_t len = TrimCommonPathPrefix(*insert_path, project_root);
-  if (len > start)
-    start = len;
-
-  for (auto& include_dir : project->quote_include_directories) {
-    len = TrimCommonPathPrefix(*insert_path, include_dir);
-    if (len > start)
-      start = len;
-  }
+  for (auto& include_dir : project->quote_include_directories)
+    start = std::max(start, TrimCommonPathPrefix(*insert_path, include_dir));
 
   for (auto& include_dir : project->angle_include_directories) {
-    len = TrimCommonPathPrefix(*insert_path, include_dir);
+    auto len = TrimCommonPathPrefix(*insert_path, include_dir);
     if (len > start) {
       start = len;
       angle = true;
@@ -115,7 +103,7 @@ void IncludeComplete::Rescan() {
                                           g_config->completion.includeBlacklist);
 
   is_scanning = true;
-  new std::thread([this]() {
+  std::thread([this]() {
     SetThreadName("scan_includes");
     Timer timer;
 
@@ -129,7 +117,7 @@ void IncludeComplete::Rescan() {
 
     timer.ResetAndPrint("[perf] Scanning for includes");
     is_scanning = false;
-  });
+  }).detach();
 }
 
 void IncludeComplete::InsertCompletionItem(const std::string& absolute_path,

src/lsp.cc

@@ -275,6 +275,19 @@ bool lsTextEdit::operator==(const lsTextEdit& that) {
   return range == that.range && newText == that.newText;
 }
 
+void Reflect(Writer& visitor, lsMarkedString& value) {
+  // If there is a language, emit a `{language:string, value:string}` object. If
+  // not, emit a string.
+  if (value.language) {
+    REFLECT_MEMBER_START();
+    REFLECT_MEMBER(language);
+    REFLECT_MEMBER(value);
+    REFLECT_MEMBER_END();
+  } else {
+    Reflect(visitor, value.value);
+  }
+}
+
 std::string Out_ShowLogMessage::method() {
   if (display_type == DisplayType::Log)
     return "window/logMessage";

src/lsp.h

@@ -239,7 +239,7 @@ MAKE_REFLECT_STRUCT(lsTextDocumentIdentifier, uri);
 struct lsVersionedTextDocumentIdentifier {
   lsDocumentUri uri;
   // The version number of this document.  number | null
-  std::variant<std::monostate, int> version;
+  std::optional<int> version;
 
   lsTextDocumentIdentifier AsTextDocumentIdentifier() const;
 };
@@ -325,12 +325,11 @@ MAKE_REFLECT_STRUCT(lsFormattingOptions, tabSize, insertSpaces);
 //
 // Note that markdown strings will be sanitized - that means html will be
 // escaped.
-struct lsMarkedString1 {
-  std::string_view language;
-  std::string_view value;
+struct lsMarkedString {
+  std::optional<std::string> language;
+  std::string value;
 };
-using lsMarkedString = std::variant<std::string_view, lsMarkedString1>;
-MAKE_REFLECT_STRUCT(lsMarkedString1, language, value);
+void Reflect(Writer& visitor, lsMarkedString& value);
 
 struct lsTextDocumentContentChangeEvent {
   // The range of the document that changed.

src/messages/ccls_freshen_index.cc

@@ -87,7 +87,7 @@ struct Handler_CclsFreshenIndex : BaseMessageHandler<In_CclsFreshenIndex> {
 
     Timer time;
     // Send index requests for every file.
-    project->Index(QueueManager::instance(), working_files, std::monostate());
+    project->Index(QueueManager::instance(), working_files, lsRequestId());
     time.ResetAndPrint("[perf] Dispatched $ccls/freshenIndex index requests");
   }
 };

src/messages/initialize.cc

@@ -518,12 +518,12 @@ struct Handler_Initialize : BaseMessageHandler<In_InitializeRequest> {
       }
       LOG_S(INFO) << "Starting " << g_config->index.threads << " indexers";
       for (int i = 0; i < g_config->index.threads; i++) {
-        new std::thread([=]() {
+        std::thread([=]() {
           SetThreadName("indexer" + std::to_string(i));
           Indexer_Main(diag_engine, file_consumer_shared, timestamp_manager,
                        import_manager, import_pipeline_status, project,
                        working_files, waiter);
-        });
+        }).detach();
       }
 
       // Start scanning include directories before dispatching project

src/messages/shutdown.cc

@@ -11,8 +11,8 @@ MAKE_REFLECT_STRUCT(In_Shutdown, id);
 REGISTER_IN_MESSAGE(In_Shutdown);
 
 struct Out_Shutdown : public lsOutMessage<Out_Shutdown> {
-  lsRequestId id;         // defaults to std::monostate (null)
-  std::monostate result;  // null
+  lsRequestId id;
+  JsonNull result;
 };
 MAKE_REFLECT_STRUCT(Out_Shutdown, jsonrpc, id, result);
 

src/messages/text_document_did_change.cc

@@ -39,7 +39,6 @@ struct Handler_TextDocumentDidChange
     }
     clang_complete->NotifyEdit(path);
     clang_complete->DiagnosticsUpdate(
-        std::monostate(),
         request->params.textDocument.AsTextDocumentIdentifier());
   }
 };

src/messages/text_document_hover.cc

@@ -5,41 +5,40 @@
 namespace {
 MethodType kMethodType = "textDocument/hover";
 
-std::pair<std::string_view, std::string_view> GetCommentsAndHover(
-    QueryDatabase* db,
+// Find the comments for |sym|, if any.
+std::optional<lsMarkedString> GetComments(QueryDatabase* db, SymbolRef sym) {
+  std::optional<lsMarkedString> ret;
+  WithEntity(db, sym, [&](const auto& entity) {
+    if (const auto* def = entity.AnyDef())
+      if (!def->comments.empty()) {
+        lsMarkedString m;
+        m.value = def->comments;
+        ret = m;
+      }
+  });
+  return ret;
+}
+
+// Returns the hover or detailed name for `sym`, if any.
+std::optional<lsMarkedString> GetHoverOrName(QueryDatabase* db,
+  const std::string& language,
   SymbolRef sym) {
-  switch (sym.kind) {
-    case SymbolKind::Type: {
-      if (const auto* def = db->GetType(sym).AnyDef()) {
-        return {def->comments, !def->hover.empty()
-                                   ? std::string_view(def->hover)
-                                   : std::string_view(def->detailed_name)};
-      }
-      break;
-    }
-    case SymbolKind::Func: {
-      if (const auto* def = db->GetFunc(sym).AnyDef()) {
-        return {def->comments, !def->hover.empty()
-                                   ? std::string_view(def->hover)
-                                   : std::string_view(def->detailed_name)};
-      }
-      break;
-    }
-    case SymbolKind::Var: {
-      if (const auto* def = db->GetVar(sym).AnyDef()) {
-        return {def->comments, !def->hover.empty()
-                                   ? std::string_view(def->hover)
-                                   : std::string_view(def->detailed_name)};
-      }
-      break;
-    }
-    case SymbolKind::File:
-    case SymbolKind::Invalid: {
-      assert(false && "unexpected");
-      break;
+
+  std::optional<lsMarkedString> ret;
+  WithEntity(db, sym, [&](const auto& entity) {
+    if (const auto* def = entity.AnyDef()) {
+      lsMarkedString m;
+      m.language = language;
+      if (!def->hover.empty()) {
+        m.value = def->hover;
+        ret = m;
+      } else if (!def->detailed_name.empty()) {
+        m.value = def->detailed_name;
+        ret = m;
       }
     }
-  return {"", ""};
+  });
+  return ret;
 }
 
 struct In_TextDocumentHover : public RequestInMessage {
@@ -66,7 +65,7 @@ void Reflect(Writer& visitor, Out_TextDocumentHover& value) {
   if (value.result)
     REFLECT_MEMBER(result);
   else {
-    // Empty std::optional<> is elided by the default serializer, we need to write
+    // Empty optional<> is elided by the default serializer, we need to write
     // |null| to be compliant with the LSP.
     visitor.Key("result");
     visitor.Null();
@@ -77,11 +76,11 @@ void Reflect(Writer& visitor, Out_TextDocumentHover& value) {
 struct Handler_TextDocumentHover : BaseMessageHandler<In_TextDocumentHover> {
   MethodType GetMethodType() const override { return kMethodType; }
   void Run(In_TextDocumentHover* request) override {
+    auto& params = request->params;
     QueryFile* file;
     if (!FindFileOrFail(db, project, request->id,
-                        request->params.textDocument.uri.GetPath(), &file)) {
+                        params.textDocument.uri.GetPath(), &file))
       return;
-    }
 
     WorkingFile* working_file =
         working_files->GetFileByFilename(file->def->path);
@@ -90,25 +89,23 @@ struct Handler_TextDocumentHover : BaseMessageHandler<In_TextDocumentHover> {
     out.id = request->id;
 
     for (SymbolRef sym :
-         FindSymbolsAtLocation(working_file, file, request->params.position)) {
+         FindSymbolsAtLocation(working_file, file, params.position)) {
       // Found symbol. Return hover.
       std::optional<lsRange> ls_range = GetLsRange(
           working_files->GetFileByFilename(file->def->path), sym.range);
       if (!ls_range)
         continue;
 
-      std::pair<std::string_view, std::string_view> comments_hover =
-          GetCommentsAndHover(db, sym);
-      if (comments_hover.first.size() || comments_hover.second.size()) {
+      std::optional<lsMarkedString> comments = GetComments(db, sym);
+      std::optional<lsMarkedString> hover =
+          GetHoverOrName(db, file->def->language, sym);
+      if (comments || hover) {
         out.result = Out_TextDocumentHover::Result();
-        if (comments_hover.first.size()) {
-          out.result->contents.emplace_back(comments_hover.first);
-        }
-        if (comments_hover.second.size()) {
-          out.result->contents.emplace_back(lsMarkedString1{
-              std::string_view(file->def->language), comments_hover.second});
-        }
         out.result->range = *ls_range;
+        if (comments)
+          out.result->contents.push_back(*comments);
+        if (hover)
+          out.result->contents.push_back(*hover);
         break;
       }
     }

src/messages/workspace_did_change_configuration.cc

@@ -33,7 +33,7 @@ struct Handler_WorkspaceDidChangeConfiguration
                        std::to_string(project->entries.size()) + " files)");
 
     time.Reset();
-    project->Index(QueueManager::instance(), working_files, std::monostate());
+    project->Index(QueueManager::instance(), working_files, lsRequestId());
     time.ResetAndPrint(
         "[perf] Dispatched workspace/didChangeConfiguration index requests");
 

src/method.cc

@@ -2,6 +2,40 @@
 
 MethodType kMethodType_Unknown = "$unknown";
 MethodType kMethodType_Exit = "exit";
-MethodType kMethodType_TextDocumentPublishDiagnostics = "textDocument/publishDiagnostics";
-MethodType kMethodType_CclsPublishInactiveRegions = "$ccls/publishInactiveRegions";
-MethodType kMethodType_CclsPublishSemanticHighlighting = "$ccls/publishSemanticHighlighting";
+MethodType kMethodType_TextDocumentPublishDiagnostics =
+    "textDocument/publishDiagnostics";
+MethodType kMethodType_CclsPublishInactiveRegions =
+    "$ccls/publishInactiveRegions";
+MethodType kMethodType_CclsPublishSemanticHighlighting =
+    "$ccls/publishSemanticHighlighting";
+
+void Reflect(Reader& visitor, lsRequestId& value) {
+  if (visitor.IsInt64()) {
+    value.type = lsRequestId::kInt;
+    value.value = visitor.GetInt64();
+  } else if (visitor.IsInt()) {
+    value.type = lsRequestId::kInt;
+    value.value = visitor.GetInt();
+  } else if (visitor.IsString()) {
+    value.type = lsRequestId::kString;
+    value.value = atoll(visitor.GetString().c_str());
+  } else {
+    value.type = lsRequestId::kNone;
+    value.value = -1;
+  }
+}
+
+void Reflect(Writer& visitor, lsRequestId& value) {
+  switch (value.type) {
+  case lsRequestId::kNone:
+    visitor.Null();
+    break;
+  case lsRequestId::kInt:
+    visitor.Int(value.value);
+    break;
+  case lsRequestId::kString:
+    auto s = std::to_string(value.value);
+    visitor.String(s.c_str(), s.length());
+    break;
+  }
+}

src/method.h

@@ -12,7 +12,18 @@ extern MethodType kMethodType_TextDocumentPublishDiagnostics;
 extern MethodType kMethodType_CclsPublishInactiveRegions;
 extern MethodType kMethodType_CclsPublishSemanticHighlighting;
 
-using lsRequestId = std::variant<std::monostate, int64_t, std::string>;
+struct lsRequestId {
+  // The client can send the request id as an int or a string. We should output
+  // the same format we received.
+  enum Type { kNone, kInt, kString };
+  Type type = kNone;
+
+  int value = -1;
+
+  bool Valid() const { return type != kNone; }
+};
+void Reflect(Reader& visitor, lsRequestId& value);
+void Reflect(Writer& visitor, lsRequestId& value);
 
 struct InMessage {
   virtual ~InMessage() = default;
@@ -32,6 +43,6 @@ struct RequestInMessage : public InMessage {
 // NotificationInMessage does not have |id|.
 struct NotificationInMessage : public InMessage {
   lsRequestId GetRequestId() const override {
-    return std::monostate();
+    return lsRequestId();
   }
 };

src/project.h

@@ -8,7 +8,6 @@
 #include <optional>
 #include <string>
 #include <unordered_map>
-#include <variant>
 #include <vector>
 
 class QueueManager;

src/serializer.cc

@@ -140,6 +140,15 @@ void Reflect(Writer& visitor, NtString& value) {
   visitor.String(s ? s : "");
 }
 
+void Reflect(Reader& visitor, JsonNull& value) {
+  assert(visitor.Format() == SerializeFormat::Json);
+  visitor.GetNull();
+}
+
+void Reflect(Writer& visitor, JsonNull& value) {
+  visitor.Null();
+}
+
 // TODO: Move this to indexer.cc
 void Reflect(Reader& visitor, IndexInclude& value) {
   REFLECT_MEMBER_START();
@@ -299,15 +308,6 @@ void Reflect(TVisitor& visitor, IndexFile& value) {
   REFLECT_MEMBER_END();
 }
 
-void Reflect(Reader& visitor, std::monostate&) {
-  assert(visitor.Format() == SerializeFormat::Json);
-  visitor.GetNull();
-}
-
-void Reflect(Writer& visitor, std::monostate&) {
-  visitor.Null();
-}
-
 void Reflect(Reader& visitor, SerializeFormat& value) {
   std::string fmt = visitor.GetString();
   value = fmt[0] == 'b' ? SerializeFormat::Binary : SerializeFormat::Json;

src/serializer.h

@@ -13,11 +13,12 @@
 #include <string>
 #include <string_view>
 #include <type_traits>
-#include <variant>
 #include <vector>
 
 enum class SerializeFormat { Binary, Json };
 
+struct JsonNull {};
+
 class Reader {
  public:
   virtual ~Reader() {}
@@ -168,20 +169,18 @@ void Reflect(Writer& visitor, std::string_view& view);
 void Reflect(Reader& visitor, NtString& value);
 void Reflect(Writer& visitor, NtString& value);
 
-// std::monostate is used to represent JSON null
-void Reflect(Reader& visitor, std::monostate&);
-void Reflect(Writer& visitor, std::monostate&);
+void Reflect(Reader& visitor, JsonNull& value);
+void Reflect(Writer& visitor, JsonNull& value);
 
 void Reflect(Reader& visitor, SerializeFormat& value);
 void Reflect(Writer& visitor, SerializeFormat& value);
 
 //// Type constructors
 
-// ReflectMember std::optional<T> is used to represent TypeScript std::optional properties
+// ReflectMember std::optional<T> is used to represent TypeScript optional properties
 // (in `key: value` context).
 // Reflect std::optional<T> is used for a different purpose, whether an object is
-// nullable (possibly in `value` context). For the nullable semantics,
-// std::variant<std::monostate, T> is recommended.
+// nullable (possibly in `value` context).
 template <typename T>
 void Reflect(Reader& visitor, std::optional<T>& value) {
   if (visitor.IsNull()) {
@@ -243,57 +242,6 @@ void ReflectMember(Writer& visitor, const char* name, Maybe<T>& value) {
   }
 }
 
-// Helper struct to reflect std::variant
-template <size_t N, typename... Ts>
-struct ReflectVariant {
-  // If T appears in Ts..., we should set the value of std::variant<Ts...> to
-  // what we get from Reader.
-  template <typename T>
-  void ReflectTag(Reader& visitor, std::variant<Ts...>& value) {
-    if constexpr (std::disjunction_v<std::is_same<T, Ts>...>) {
-      T a;
-      Reflect(visitor, a);
-      value = std::move(a);
-    }
-  }
-
-  void operator()(Reader& visitor, std::variant<Ts...>& value) {
-    // Based on tag dispatch, call different ReflectTag helper.
-    if (visitor.IsNull())
-      ReflectTag<std::monostate>(visitor, value);
-    // It is possible that IsInt64() && IsInt(). We don't call ReflectTag<int>
-    // if int is not in Ts...
-    else if (std::disjunction_v<std::is_same<int, Ts>...> && visitor.IsInt())
-      ReflectTag<int>(visitor, value);
-    else if (visitor.IsInt64())
-      ReflectTag<int64_t>(visitor, value);
-    else if (visitor.IsString())
-      ReflectTag<std::string>(visitor, value);
-    else
-      assert(0);
-  }
-
-  // Check which type the variant contains and call corresponding Reflect.
-  void operator()(Writer& visitor, std::variant<Ts...>& value) {
-    if (value.index() == N - 1)
-      Reflect(visitor, std::get<N - 1>(value));
-    else
-      ReflectVariant<N - 1, Ts...>()(visitor, value);
-  }
-};
-
-// Writer reflection on std::variant recurses. This is induction basis.
-template <typename... Ts>
-struct ReflectVariant<0, Ts...> {
-  void operator()(Writer& visitor, std::variant<Ts...>& value) {}
-};
-
-// std::variant
-template <typename TVisitor, typename... Ts>
-void Reflect(TVisitor& visitor, std::variant<Ts...>& value) {
-  ReflectVariant<sizeof...(Ts), Ts...>()(visitor, value);
-}
-
 // std::vector
 template <typename T>
 void Reflect(Reader& visitor, std::vector<T>& values) {

src/working_files.cc

@@ -24,19 +24,15 @@ lsPosition GetPositionForOffset(const std::string& content, int offset) {
   if (offset >= content.size())
     offset = (int)content.size() - 1;
 
-  lsPosition result;
+  int line = 0, col = 0;
   int i = 0;
-  while (i < offset) {
-    if (content[i] == '\n') {
-      result.line += 1;
-      result.character = 0;
-    } else {
-      result.character += 1;
+  for (; i < offset; i++) {
+    if (content[i] == '\n')
+      line++, col = 0;
+    else
+      col++;
   }
-    ++i;
-  }
-
-  return result;
+  return {line, col};
 }
 
 std::vector<std::string> ToLines(const std::string& content) {
@@ -511,8 +507,8 @@ void WorkingFiles::OnChange(const lsTextDocumentDidChangeParams& change) {
   }
 
   // version: number | null
-  if (std::holds_alternative<int>(change.textDocument.version))
-    file->version = std::get<int>(change.textDocument.version);
+  if (change.textDocument.version)
+    file->version = *change.textDocument.version;
 
   for (const lsTextDocumentContentChangeEvent& diff : change.contentChanges) {
     // Per the spec replace everything if the rangeLength and range are not set.