LibKeyboard: Change some Optional<T> returns to ErrorOr<T>

Makes CharacterMapFile::load_from_file and CharacterMap::load_from_file
return ErrorOr instead of Optional. This makes them a little nicer to
use and a little easier to read, as they seem to have been approximating
this.

Userland/Libraries/LibKeyboard/CharacterMap.cpp

@@ -17,13 +17,11 @@ namespace Keyboard {
 #ifndef KERNEL
 // The Kernel explicitly and exclusively links only this file into it.
 // Thus, we cannot even include a reference to the symbol `CharacterMapFile::load_from_file`.
-Optional<CharacterMap> CharacterMap::load_from_file(const String& map_name)
+ErrorOr<CharacterMap> CharacterMap::load_from_file(const String& map_name)
 {
-    auto result = CharacterMapFile::load_from_file(map_name);
-    if (!result.has_value())
-        return {};
+    auto result = TRY(CharacterMapFile::load_from_file(map_name));
 
-    return CharacterMap(map_name, result.value());
+    return CharacterMap(map_name, result);
 }
 #endif
 

Userland/Libraries/LibKeyboard/CharacterMap.h

@@ -19,7 +19,7 @@ class CharacterMap {
 
 public:
     CharacterMap(const String& map_name, const CharacterMapData& map_data);
-    static Optional<CharacterMap> load_from_file(const String& filename);
+    static ErrorOr<CharacterMap> load_from_file(const String& filename);
 
 #ifndef KERNEL
     int set_system_map();

Userland/Libraries/LibKeyboard/CharacterMapFile.cpp

@@ -11,7 +11,7 @@
 
 namespace Keyboard {
 
-Optional<CharacterMapData> CharacterMapFile::load_from_file(const String& filename)
+ErrorOr<CharacterMapData> CharacterMapFile::load_from_file(const String& filename)
 {
     auto path = filename;
     if (!path.ends_with(".json")) {
@@ -22,20 +22,10 @@ Optional<CharacterMapData> CharacterMapFile::load_from_file(const String& filena
         path = full_path.to_string();
     }
 
-    auto file = Core::File::construct(path);
-    file->open(Core::OpenMode::ReadOnly);
-    if (!file->is_open()) {
-        dbgln("Failed to open {}: {}", path, file->error_string());
-        return {};
-    }
-
+    auto file = TRY(Core::File::open(path, Core::OpenMode::ReadOnly));
     auto file_contents = file->read_all();
-    auto json_result = JsonValue::from_string(file_contents);
-    if (json_result.is_error()) {
-        dbgln("Failed to load character map from file {}", path);
-        return {};
-    }
-    auto json = json_result.value().as_object();
+    auto json_result = TRY(JsonValue::from_string(file_contents));
+    const auto& json = json_result.as_object();
 
     Vector<u32> map = read_map(json, "map");
     Vector<u32> shift_map = read_map(json, "shift_map");

Userland/Libraries/LibKeyboard/CharacterMapFile.h

@@ -14,7 +14,7 @@ namespace Keyboard {
 class CharacterMapFile {
 
 public:
-    static Optional<CharacterMapData> load_from_file(const String& filename);
+    static ErrorOr<CharacterMapData> load_from_file(const String& filename);
 
 private:
     static Vector<u32> read_map(const JsonObject& json, const String& name);

Userland/Utilities/keymap.cpp

@@ -34,7 +34,7 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
     }
 
     auto character_map = Keyboard::CharacterMap::load_from_file(path);
-    if (!character_map.has_value()) {
+    if (character_map.is_error()) {
         warnln("Cannot read keymap {}", path);
         warnln("Hint: Must be either a keymap name (e.g. 'en-us') or a full path.");
         return 1;