Enum with Expando

main.dart

/*
 * Enum with expando properties
 * https://gist.github.com/PlugFox/ed18b5ce21c5286b5a95d2efa34958f1
 * https://dartpad.dev/ed18b5ce21c5286b5a95d2efa34958f1
 * Matiunin Mikhail <plugfox@gmail.com>, 07 June 2022
 */

void main() {
  const red = Color.red, green = Color.green, blue = Color.blue;
  print('${red.color}, ${green.color}, ${blue.color}');
  // <unknown>, <unknown>, <unknown>
  red.color = 'red';
  blue.color = 'blue';
  print('${red.color}, ${green.color}, ${blue.color}');
  // red, <unknown>, blue
  print(Color.red.color);
  // red
}

enum Color {
  red,
  green,
  blue;

  String get color => _expando[this] ?? '<unknown>';
  set color(String color) => _expando[this] = color;

  static final Expando<String> _expando = Expando<String>();
}