freezed 3.0.0-0.0.dev

Code generation for immutable classes that has a simple syntax/API without compromising on the features.

example/main.dart

// ignore_for_file: avoid_unused_constructor_parameters

import 'package:freezed/freezed.dart';

// The usual syntax, based on constructors.
// We no-longer use "factory" constructors.
@Freezed()
class Person {
  Person(
    String name, {
    required int age,
  });
}

// Alternatively, you can define classes using fields:

@Freezed()
class Person2 {
  final String name;
  final int age;
}

void main() {
  var person = Person('John', age: 30);
  person = person.copyWith(age: 31);

  print(person.name); // John
  print(person.age); // 31

  // Person2 works the same!
  var person2 = Person2(name: 'John', age: 30);
  person2 = person2.copyWith(age: 31);
}

// ---- Advanced usage: Unions ----

class Engine {}

@Freezed()
sealed class Vehicle {
  final Engine engine;
}

@Freezed()
class Plane implements Vehicle {
  final Wing wing;

  // Currently necessary due to augmentation libraries not being fully implemented.
  // This won't be needed in the future.
  @override
  final Engine engine;
}

class Wing {}

@Freezed()
class Car implements Vehicle {
  final Wheel wheel;

  @override
  final Engine engine;
}

class Wheel {}