functional_enum 1.1.0

Code generator for functional enum that makes the use of enums much better.

Functional Enum

Code generator for functional enum that makes the use of enums much better.

Usage

import 'package:functional_enum_annotation/functional_enum_annotation.dart';

part 'main.g.dart';

@functional_enum
enum Shape { square, circle, triangle }

void main() {
  final shape = Shape.circle;

  // all cases must be handled
  final message = shape.when(
    square: () => 'I am a Square',
    circle: () => 'I am a Circle',
    triangle: () => 'I am a Triangle',
  );
  print(message); // I am a Circle

  // all cases may not be handled but `orElse` cannot be null
  final canBeRotated = shape.maybeWhen(
    circle: () => false,
    orElse: () => true,
  );
  print(canBeRotated); // false

  // equivalent to print(shape == Shape.circle)
  print(shape.isCircle); // true
  print(shape.isSquare); // false
  print(shape.isTriangle); // false
}

With flutter:

@functional_enum
enum AppState { initial, loading, loaded }

class ExampleWidget extends StatelessWidget {
  final Appstate appState;

  const ExampleWidget({Key key, this.appState}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return appState.when(
      initial: () => SizedBox(),
      loading: () => CircularProgressIndicator(),
      loaded: () => HomePage(),
    );
  }
}