Initial flame_lua_runtime package

lib/runtime/commands/command_composite.dart

@@ -0,0 +1,52 @@
+part of 'command_executor.dart';
+
+extension _CommandExecutorComposite on CommandExecutor {
+  Future<_CommandResult> _sequence(
+    RuntimeCommand command,
+    _CommandContext context,
+    RuntimeCommandHandle? handle,
+  ) async {
+    final commands = _commandsFromPayload(command);
+    final childContext = _childContextFor(command, context);
+    for (final child in commands) {
+      if (_disposed ||
+          (handle?.isCancelled ?? false) ||
+          !_scopeIsAlive(childContext.scope)) {
+        return _CommandResult.cancelled;
+      }
+      final result = await _execute(child, childContext);
+      if (result == _CommandResult.cancelled) {
+        return _CommandResult.cancelled;
+      }
+    }
+
+    if (_disposed ||
+        (handle?.isCancelled ?? false) ||
+        !_scopeIsAlive(childContext.scope)) {
+      return _CommandResult.cancelled;
+    }
+    _emitCommandCompletion(command, childContext);
+    return _CommandResult.completed;
+  }
+
+  Future<_CommandResult> _parallel(
+    RuntimeCommand command,
+    _CommandContext context,
+    RuntimeCommandHandle? handle,
+  ) async {
+    final commands = _commandsFromPayload(command);
+    final childContext = _childContextFor(command, context);
+    final results = await Future.wait(
+      commands.map((child) => _execute(child, childContext)),
+    );
+    if (_disposed ||
+        (handle?.isCancelled ?? false) ||
+        !_scopeIsAlive(childContext.scope) ||
+        results.contains(_CommandResult.cancelled)) {
+      return _CommandResult.cancelled;
+    }
+
+    _emitCommandCompletion(command, childContext);
+    return _CommandResult.completed;
+  }
+}