Dart 3 is coming around mid-2023

[agordeev]

According to the announcement, the next major release will bring us few features that are covered by freezed:

Sealed classes

See spec

Usage:

sealed class Shape {
  double calculateArea();
}

class Square implements Shape {
  final double length;
  Square(this.length);
  double calculateArea() => length * length;
}

class Circle implements Shape {
  final double radius;
  ...
}

double calculateArea(Shape shape) => switch (shape) {
  Square(length: var l) => l * l,
  Circle(radius: var r) => math.pi * r * r
};

Macros (static metaprogramming)

See spec

This supersedes the code generation.

Question

@rrousselGit giving all that, how do you see the future of freezed?

[rrousselGit]

Once Dart has built-in pattern matching+sealed classes, Freezed will probably slowly fade away.

Depending on when metaprogramming is released, I may migrate Freezed to metaprogramming though. As people are unlikely to refactor their Freezed classes into sealed classes in a quick fashion

[thipokch]

Since Dart 3 is currently being previewed on Flutter 3.9.0-1.0.pre.2, I'm wondering if anyone have tried running this package on it? I also assume that freezed is still useful for the following:

• override toString, operator ==, hashCode
• implement a copyWith method to clone the object
• handling de/serialization

[tjarvstrand]

freezed will continue to provide value, if a bit more limited in scope, in terms of data classes. Kotlin has sealed classes and if/switch expressions and Scala also has pattern matching, but immutable data classes (or case classes in Scala) are still very useful and ubiquitous in both languages

My 2c.