FlutterRiverpod 创建复杂对象的副本，其值在某处发生变化

各位编码员.我正在学习Riverpod州管理RN.在文档中，Riverpod的作者建议尽可能使用不变性.所以我想要管理一些复杂对象状态，我必须创建状态实例的副本.我有一些Snadbox项目来测试Riverpod的功能.有一个名为Menu(用于餐馆)的复杂对象(请参见下面的代码).我不知道如何发出新的状态，并在其中的某个深处发生一些变化.

使用冻结和FAST_IMMUTABLE_COLLECTIONS(对于IList)，对吗？

@freezed
class Menu with _$Menu {
  const factory Menu({
    required String? currency,
    required WeeklyMenu? weeklyMenu,
    required StaticMenu? staticMenu,
  }) = _Menu;

  factory Menu.fromJson(Map<String, Object?> json) =>
      _$MenuFromJson(json);
}

@freezed
class WeeklyMenu with _$WeeklyMenu {
  const factory WeeklyMenu({
    required IList<Day>? dayList,
  }) = _WeeklyMenu;

  factory WeeklyMenu.fromJson(Map<String, Object?> json) =>
      _$WeeklyMenuFromJson(json);
}

@freezed
class StaticMenu with _$StaticMenu {
  const factory StaticMenu({
    required IList<MealGroup>? mealGroupList,
    required IList<DrinkGroup>? drinkGroupList,
  }) = _StaticMenu;

  factory StaticMenu.fromJson(Map<String, Object?> json) =>
      _$StaticMenuFromJson(json);
}

@freezed
class Day with _$Day {
  const factory Day({
    required String? id,
    required IList<Meal>? mealList,
    required bool? isChecked,
  }) = _Day;

  factory Day.fromJson(Map<String, Object?> json) => _$DayFromJson(json);
}


@freezed
class MealGroup with _$MealGroup {
  const factory MealGroup({
    required String? id,
    required String? description,
    required String? note,
    required IList<Meal>? mealList,
    required bool? isChecked,
  }) = _MealGroup;

  factory MealGroup.fromJson(Map<String, Object?> json) =>
      _$MealGroupFromJson(json);
}

@freezed
class DrinkGroup with _$DrinkGroup {
  const factory DrinkGroup({
    required String? id,
    required String? description,
    required String? note,
    required IList<Drink>? drinkList,
    required bool? isChecked,
  }) = _DrinkGroup;

  factory DrinkGroup.fromJson(Map<String, Object?> json) =>
      _$DrinkGroupFromJson(json);
}

@freezed
class Meal with _$Meal {
  const factory Meal({
    required String? id,
    required String? name,
    required String? price,
  }) = _Meal;

  factory Meal.fromJson(Map<String, Object?> json) => _$MealFromJson(json);
}


@freezed
class Drink with _$Drink {
  const factory Drink({
    required String? id,
    required String? name,
    required String? price,
  }) = _Drink;

  factory Drink.fromJson(Map<String, Object?> json) => _$DrinkFromJson(json);
}

这是MealGroup的餐单(4EX)，里面有带StaticMenu子类的课程菜单(永久提供餐饮).猪肉，意大利面，素食，……)，每个组都有唯一的ID，还包含具有唯一ID的班级餐列表.现在我想创建一个方法，它发出新的状态，但带有从下往下添加/更新/删除的饭菜，但我想我缺乏语法知识，也不知道如何写下来.

@riverpod
class MenuNotifier extends _$MenuNotifier {
  @override
  Menu build() {
    return const Menu(
      currency: 'Kč',
      staticMenu: null,
      weeklyMenu: null,
    );
  }

  void initializeMenu() async {
    final menu = await ServerHelper.initializeLocalJson();
    state = menu;
  }

  Future<void> updateOnServer() async {
    ServerHelper.sendMenuToServer(state);
  }

  void updateMealInMealGroup({
    required String mealGroupUid,
    required String mealUid,
    required Meal meal,
  }) {
    //state = state.copyWith(staticMenu: state.staticMenu?.mealGroupList);
  }

  void addMealToMealGroup({
    required String mealGroupUid,
    required String mealUid,
    required Meal meal,
  }) {  }

  void deleteMealinMealGroup({
    required String mealGroupUid,
    required String mealUid,
  }) {  }
}

感谢您的帮助:)