LibChess: Return Commands by pointer from `FooCommand::from_string()`

This removes this slightly silly pattern:
`make<FooCommand>(FooCommand::from_string(s))`

Also, let's propagate OOM here, even if nobody reacts to it yet.

Userland/Libraries/LibChess/UCICommand.cpp

@@ -9,12 +9,12 @@
 
 namespace Chess::UCI {
 
-UCICommand UCICommand::from_string(StringView command)
+ErrorOr<NonnullOwnPtr<UCICommand>> UCICommand::from_string(StringView command)
 {
     auto tokens = command.split_view(' ');
     VERIFY(tokens[0] == "uci");
     VERIFY(tokens.size() == 1);
-    return UCICommand();
+    return adopt_nonnull_own_or_enomem(new (nothrow) UCICommand);
 }
 
 DeprecatedString UCICommand::to_deprecated_string() const
@@ -22,15 +22,15 @@ DeprecatedString UCICommand::to_deprecated_string() const
     return "uci\n";
 }
 
-DebugCommand DebugCommand::from_string(StringView command)
+ErrorOr<NonnullOwnPtr<DebugCommand>> DebugCommand::from_string(StringView command)
 {
     auto tokens = command.split_view(' ');
     VERIFY(tokens[0] == "debug");
     VERIFY(tokens.size() == 2);
     if (tokens[1] == "on")
-        return DebugCommand(Flag::On);
+        return adopt_nonnull_own_or_enomem(new (nothrow) DebugCommand(Flag::On));
     if (tokens[1] == "off")
-        return DebugCommand(Flag::Off);
+        return adopt_nonnull_own_or_enomem(new (nothrow) DebugCommand(Flag::Off));
 
     VERIFY_NOT_REACHED();
 }
@@ -44,12 +44,12 @@ DeprecatedString DebugCommand::to_deprecated_string() const
     }
 }
 
-IsReadyCommand IsReadyCommand::from_string(StringView command)
+ErrorOr<NonnullOwnPtr<IsReadyCommand>> IsReadyCommand::from_string(StringView command)
 {
     auto tokens = command.split_view(' ');
     VERIFY(tokens[0] == "isready");
     VERIFY(tokens.size() == 1);
-    return IsReadyCommand();
+    return adopt_nonnull_own_or_enomem(new (nothrow) IsReadyCommand);
 }
 
 DeprecatedString IsReadyCommand::to_deprecated_string() const
@@ -57,7 +57,7 @@ DeprecatedString IsReadyCommand::to_deprecated_string() const
     return "isready\n";
 }
 
-SetOptionCommand SetOptionCommand::from_string(StringView command)
+ErrorOr<NonnullOwnPtr<SetOptionCommand>> SetOptionCommand::from_string(StringView command)
 {
     auto tokens = command.split_view(' ');
     VERIFY(tokens[0] == "setoption");
@@ -75,13 +75,13 @@ SetOptionCommand SetOptionCommand::from_string(StringView command)
                 in_value = true;
                 continue;
             }
-            name.append(part);
-            name.append(' ');
+            TRY(name.try_append(part));
+            TRY(name.try_append(' '));
             continue;
         }
         if (in_value) {
-            value.append(part);
-            value.append(' ');
+            TRY(value.try_append(part));
+            TRY(value.try_append(' '));
             continue;
         }
         if (part == "name") {
@@ -92,7 +92,7 @@ SetOptionCommand SetOptionCommand::from_string(StringView command)
 
     VERIFY(!name.is_empty());
 
-    return SetOptionCommand(name.to_deprecated_string().trim_whitespace(), value.to_deprecated_string().trim_whitespace());
+    return adopt_nonnull_own_or_enomem(new (nothrow) SetOptionCommand(name.to_deprecated_string().trim_whitespace(), value.to_deprecated_string().trim_whitespace()));
 }
 
 DeprecatedString SetOptionCommand::to_deprecated_string() const
@@ -108,7 +108,7 @@ DeprecatedString SetOptionCommand::to_deprecated_string() const
     return builder.to_deprecated_string();
 }
 
-PositionCommand PositionCommand::from_string(StringView command)
+ErrorOr<NonnullOwnPtr<PositionCommand>> PositionCommand::from_string(StringView command)
 {
     auto tokens = command.split_view(' ');
     VERIFY(tokens.size() >= 3);
@@ -121,9 +121,9 @@ PositionCommand PositionCommand::from_string(StringView command)
 
     Vector<Move> moves;
     for (size_t i = 3; i < tokens.size(); ++i) {
-        moves.append(Move(tokens[i]));
+        TRY(moves.try_append(Move(tokens[i])));
     }
-    return PositionCommand(fen, moves);
+    return adopt_nonnull_own_or_enomem(new (nothrow) PositionCommand(fen, moves));
 }
 
 DeprecatedString PositionCommand::to_deprecated_string() const
@@ -144,46 +144,46 @@ DeprecatedString PositionCommand::to_deprecated_string() const
     return builder.to_deprecated_string();
 }
 
-GoCommand GoCommand::from_string(StringView command)
+ErrorOr<NonnullOwnPtr<GoCommand>> GoCommand::from_string(StringView command)
 {
     auto tokens = command.split_view(' ');
     VERIFY(tokens[0] == "go");
 
-    GoCommand go_command;
+    auto go_command = TRY(adopt_nonnull_own_or_enomem(new (nothrow) GoCommand));
     for (size_t i = 1; i < tokens.size(); ++i) {
         if (tokens[i] == "searchmoves") {
             VERIFY_NOT_REACHED();
         } else if (tokens[i] == "ponder") {
-            go_command.ponder = true;
+            go_command->ponder = true;
         } else if (tokens[i] == "wtime") {
             VERIFY(i++ < tokens.size());
-            go_command.wtime = tokens[i].to_int().value();
+            go_command->wtime = tokens[i].to_int().value();
         } else if (tokens[i] == "btime") {
             VERIFY(i++ < tokens.size());
-            go_command.btime = tokens[i].to_int().value();
+            go_command->btime = tokens[i].to_int().value();
         } else if (tokens[i] == "winc") {
             VERIFY(i++ < tokens.size());
-            go_command.winc = tokens[i].to_int().value();
+            go_command->winc = tokens[i].to_int().value();
         } else if (tokens[i] == "binc") {
             VERIFY(i++ < tokens.size());
-            go_command.binc = tokens[i].to_int().value();
+            go_command->binc = tokens[i].to_int().value();
         } else if (tokens[i] == "movestogo") {
             VERIFY(i++ < tokens.size());
-            go_command.movestogo = tokens[i].to_int().value();
+            go_command->movestogo = tokens[i].to_int().value();
         } else if (tokens[i] == "depth") {
             VERIFY(i++ < tokens.size());
-            go_command.depth = tokens[i].to_int().value();
+            go_command->depth = tokens[i].to_int().value();
         } else if (tokens[i] == "nodes") {
             VERIFY(i++ < tokens.size());
-            go_command.nodes = tokens[i].to_int().value();
+            go_command->nodes = tokens[i].to_int().value();
         } else if (tokens[i] == "mate") {
             VERIFY(i++ < tokens.size());
-            go_command.mate = tokens[i].to_int().value();
+            go_command->mate = tokens[i].to_int().value();
         } else if (tokens[i] == "movetime") {
             VERIFY(i++ < tokens.size());
-            go_command.movetime = tokens[i].to_int().value();
+            go_command->movetime = tokens[i].to_int().value();
         } else if (tokens[i] == "infinite") {
-            go_command.infinite = true;
+            go_command->infinite = true;
         }
     }
 
@@ -230,12 +230,12 @@ DeprecatedString GoCommand::to_deprecated_string() const
     return builder.to_deprecated_string();
 }
 
-StopCommand StopCommand::from_string(StringView command)
+ErrorOr<NonnullOwnPtr<StopCommand>> StopCommand::from_string(StringView command)
 {
     auto tokens = command.split_view(' ');
     VERIFY(tokens[0] == "stop");
     VERIFY(tokens.size() == 1);
-    return StopCommand();
+    return adopt_nonnull_own_or_enomem(new (nothrow) StopCommand);
 }
 
 DeprecatedString StopCommand::to_deprecated_string() const
@@ -243,22 +243,22 @@ DeprecatedString StopCommand::to_deprecated_string() const
     return "stop\n";
 }
 
-IdCommand IdCommand::from_string(StringView command)
+ErrorOr<NonnullOwnPtr<IdCommand>> IdCommand::from_string(StringView command)
 {
     auto tokens = command.split_view(' ');
     VERIFY(tokens[0] == "id");
     StringBuilder value;
     for (size_t i = 2; i < tokens.size(); ++i) {
         if (i != 2)
-            value.append(' ');
+            TRY(value.try_append(' '));
 
-        value.append(tokens[i]);
+        TRY(value.try_append(tokens[i]));
     }
 
     if (tokens[1] == "name") {
-        return IdCommand(Type::Name, value.to_deprecated_string());
+        return adopt_nonnull_own_or_enomem(new (nothrow) IdCommand(Type::Name, value.to_deprecated_string()));
     } else if (tokens[1] == "author") {
-        return IdCommand(Type::Author, value.to_deprecated_string());
+        return adopt_nonnull_own_or_enomem(new (nothrow) IdCommand(Type::Author, value.to_deprecated_string()));
     }
     VERIFY_NOT_REACHED();
 }
@@ -277,12 +277,12 @@ DeprecatedString IdCommand::to_deprecated_string() const
     return builder.to_deprecated_string();
 }
 
-UCIOkCommand UCIOkCommand::from_string(StringView command)
+ErrorOr<NonnullOwnPtr<UCIOkCommand>> UCIOkCommand::from_string(StringView command)
 {
     auto tokens = command.split_view(' ');
     VERIFY(tokens[0] == "uciok");
     VERIFY(tokens.size() == 1);
-    return UCIOkCommand();
+    return adopt_nonnull_own_or_enomem(new (nothrow) UCIOkCommand);
 }
 
 DeprecatedString UCIOkCommand::to_deprecated_string() const
@@ -290,12 +290,12 @@ DeprecatedString UCIOkCommand::to_deprecated_string() const
     return "uciok\n";
 }
 
-ReadyOkCommand ReadyOkCommand::from_string(StringView command)
+ErrorOr<NonnullOwnPtr<ReadyOkCommand>> ReadyOkCommand::from_string(StringView command)
 {
     auto tokens = command.split_view(' ');
     VERIFY(tokens[0] == "readyok");
     VERIFY(tokens.size() == 1);
-    return ReadyOkCommand();
+    return adopt_nonnull_own_or_enomem(new (nothrow) ReadyOkCommand);
 }
 
 DeprecatedString ReadyOkCommand::to_deprecated_string() const
@@ -303,12 +303,12 @@ DeprecatedString ReadyOkCommand::to_deprecated_string() const
     return "readyok\n";
 }
 
-BestMoveCommand BestMoveCommand::from_string(StringView command)
+ErrorOr<NonnullOwnPtr<BestMoveCommand>> BestMoveCommand::from_string(StringView command)
 {
     auto tokens = command.split_view(' ');
     VERIFY(tokens[0] == "bestmove");
     VERIFY(tokens.size() == 2);
-    return BestMoveCommand(Move(tokens[1]));
+    return adopt_nonnull_own_or_enomem(new (nothrow) BestMoveCommand(Move(tokens[1])));
 }
 
 DeprecatedString BestMoveCommand::to_deprecated_string() const
@@ -320,7 +320,7 @@ DeprecatedString BestMoveCommand::to_deprecated_string() const
     return builder.to_deprecated_string();
 }
 
-InfoCommand InfoCommand::from_string([[maybe_unused]] StringView command)
+ErrorOr<NonnullOwnPtr<InfoCommand>> InfoCommand::from_string([[maybe_unused]] StringView command)
 {
     // FIXME: Implement this.
     VERIFY_NOT_REACHED();
@@ -333,12 +333,12 @@ DeprecatedString InfoCommand::to_deprecated_string() const
     return "info";
 }
 
-QuitCommand QuitCommand::from_string([[maybe_unused]] StringView command)
+ErrorOr<NonnullOwnPtr<QuitCommand>> QuitCommand::from_string(StringView command)
 {
     auto tokens = command.split_view(' ');
     VERIFY(tokens[0] == "quit");
     VERIFY(tokens.size() == 1);
-    return QuitCommand();
+    return adopt_nonnull_own_or_enomem(new (nothrow) QuitCommand);
 }
 
 DeprecatedString QuitCommand::to_deprecated_string() const

Userland/Libraries/LibChess/UCICommand.h

@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2020-2022, the SerenityOS developers.
+ * Copyright (c) 2023, Sam Atkins <atkinssj@serenityos.org>
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -38,15 +39,15 @@ public:
         Info,
         Option,
     };
+    virtual DeprecatedString to_deprecated_string() const = 0;
+
+    virtual ~Command() = default;
 
+protected:
     explicit Command(Type type)
         : Core::Event(to_underlying(type))
     {
     }
-
-    virtual DeprecatedString to_deprecated_string() const = 0;
-
-    virtual ~Command() = default;
 };
 
 class UCICommand : public Command {
@@ -56,7 +57,7 @@ public:
     {
     }
 
-    static UCICommand from_string(StringView command);
+    static ErrorOr<NonnullOwnPtr<UCICommand>> from_string(StringView command);
 
     virtual DeprecatedString to_deprecated_string() const override;
 };
@@ -74,7 +75,7 @@ public:
     {
     }
 
-    static DebugCommand from_string(StringView command);
+    static ErrorOr<NonnullOwnPtr<DebugCommand>> from_string(StringView command);
 
     virtual DeprecatedString to_deprecated_string() const override;
 
@@ -91,7 +92,7 @@ public:
     {
     }
 
-    static IsReadyCommand from_string(StringView command);
+    static ErrorOr<NonnullOwnPtr<IsReadyCommand>> from_string(StringView command);
 
     virtual DeprecatedString to_deprecated_string() const override;
 };
@@ -105,7 +106,7 @@ public:
     {
     }
 
-    static SetOptionCommand from_string(StringView command);
+    static ErrorOr<NonnullOwnPtr<SetOptionCommand>> from_string(StringView command);
 
     virtual DeprecatedString to_deprecated_string() const override;
 
@@ -126,7 +127,7 @@ public:
     {
     }
 
-    static PositionCommand from_string(StringView command);
+    static ErrorOr<NonnullOwnPtr<PositionCommand>> from_string(StringView command);
 
     virtual DeprecatedString to_deprecated_string() const override;
 
@@ -145,7 +146,7 @@ public:
     {
     }
 
-    static GoCommand from_string(StringView command);
+    static ErrorOr<NonnullOwnPtr<GoCommand>> from_string(StringView command);
 
     virtual DeprecatedString to_deprecated_string() const override;
 
@@ -170,7 +171,7 @@ public:
     {
     }
 
-    static StopCommand from_string(StringView command);
+    static ErrorOr<NonnullOwnPtr<StopCommand>> from_string(StringView command);
 
     virtual DeprecatedString to_deprecated_string() const override;
 };
@@ -189,7 +190,7 @@ public:
     {
     }
 
-    static IdCommand from_string(StringView command);
+    static ErrorOr<NonnullOwnPtr<IdCommand>> from_string(StringView command);
 
     virtual DeprecatedString to_deprecated_string() const override;
 
@@ -208,7 +209,7 @@ public:
     {
     }
 
-    static UCIOkCommand from_string(StringView command);
+    static ErrorOr<NonnullOwnPtr<UCIOkCommand>> from_string(StringView command);
 
     virtual DeprecatedString to_deprecated_string() const override;
 };
@@ -220,7 +221,7 @@ public:
     {
     }
 
-    static ReadyOkCommand from_string(StringView command);
+    static ErrorOr<NonnullOwnPtr<ReadyOkCommand>> from_string(StringView command);
 
     virtual DeprecatedString to_deprecated_string() const override;
 };
@@ -233,7 +234,7 @@ public:
     {
     }
 
-    static BestMoveCommand from_string(StringView command);
+    static ErrorOr<NonnullOwnPtr<BestMoveCommand>> from_string(StringView command);
 
     virtual DeprecatedString to_deprecated_string() const override;
 
@@ -250,7 +251,7 @@ public:
     {
     }
 
-    static InfoCommand from_string(StringView command);
+    static ErrorOr<NonnullOwnPtr<InfoCommand>> from_string(StringView command);
 
     virtual DeprecatedString to_deprecated_string() const override;
 
@@ -275,7 +276,7 @@ public:
     {
     }
 
-    static QuitCommand from_string(StringView command);
+    static ErrorOr<NonnullOwnPtr<QuitCommand>> from_string(StringView command);
 
     virtual DeprecatedString to_deprecated_string() const override;
 };

Userland/Libraries/LibChess/UCIEndpoint.cpp

@@ -89,31 +89,31 @@ NonnullOwnPtr<Command> Endpoint::read_command()
     dbgln_if(UCI_DEBUG, "{} Received UCI Command: {}", class_name(), line);
 
     if (line == "uci") {
-        return make<UCICommand>(UCICommand::from_string(line));
+        return UCICommand::from_string(line).release_value_but_fixme_should_propagate_errors();
     } else if (line.starts_with("debug"sv)) {
-        return make<DebugCommand>(DebugCommand::from_string(line));
+        return DebugCommand::from_string(line).release_value_but_fixme_should_propagate_errors();
     } else if (line.starts_with("isready"sv)) {
-        return make<IsReadyCommand>(IsReadyCommand::from_string(line));
+        return IsReadyCommand::from_string(line).release_value_but_fixme_should_propagate_errors();
     } else if (line.starts_with("setoption"sv)) {
-        return make<SetOptionCommand>(SetOptionCommand::from_string(line));
+        return SetOptionCommand::from_string(line).release_value_but_fixme_should_propagate_errors();
     } else if (line.starts_with("position"sv)) {
-        return make<PositionCommand>(PositionCommand::from_string(line));
+        return PositionCommand::from_string(line).release_value_but_fixme_should_propagate_errors();
     } else if (line.starts_with("go"sv)) {
-        return make<GoCommand>(GoCommand::from_string(line));
+        return GoCommand::from_string(line).release_value_but_fixme_should_propagate_errors();
     } else if (line.starts_with("stop"sv)) {
-        return make<StopCommand>(StopCommand::from_string(line));
+        return StopCommand::from_string(line).release_value_but_fixme_should_propagate_errors();
     } else if (line.starts_with("id"sv)) {
-        return make<IdCommand>(IdCommand::from_string(line));
+        return IdCommand::from_string(line).release_value_but_fixme_should_propagate_errors();
     } else if (line.starts_with("uciok"sv)) {
-        return make<UCIOkCommand>(UCIOkCommand::from_string(line));
+        return UCIOkCommand::from_string(line).release_value_but_fixme_should_propagate_errors();
     } else if (line.starts_with("readyok"sv)) {
-        return make<ReadyOkCommand>(ReadyOkCommand::from_string(line));
+        return ReadyOkCommand::from_string(line).release_value_but_fixme_should_propagate_errors();
     } else if (line.starts_with("bestmove"sv)) {
-        return make<BestMoveCommand>(BestMoveCommand::from_string(line));
+        return BestMoveCommand::from_string(line).release_value_but_fixme_should_propagate_errors();
     } else if (line.starts_with("info"sv)) {
-        return make<InfoCommand>(InfoCommand::from_string(line));
+        return InfoCommand::from_string(line).release_value_but_fixme_should_propagate_errors();
     } else if (line.starts_with("quit"sv)) {
-        return make<QuitCommand>(QuitCommand::from_string(line));
+        return QuitCommand::from_string(line).release_value_but_fixme_should_propagate_errors();
     }
 
     dbgln("command line: {}", line);