flutter_resultable #

A lightweight, expressive Result type for Flutter and Dart to model success and failure outcomes without exceptions, inspired by functional programming patterns like Either.

✨ Features #

• ✅ Result.success and Result.failure to represent outcomes cleanly.
• 🔁 Pattern matching via when, map, and maybeWhen (thanks to freezed).
• ⚡ Strongly typed error and success handling.
• 💡 Easily testable and composable.
• 🪶 Minimal, clean API.

📦 Installation #

Add this to your pubspec.yaml:

dependencies:
  flutter_resultable: ^1.0.0

Then run:

flutter pub get

🔧 Usage #

Define a result-returning function #

import 'package:flutter_resultable/flutter_resultable.dart';

Result<String, int> divide(int a, int b) {
  if (b == 0) return Result.failure("Division by zero");
  return Result.success(a ~/ b);
}

Handle with pattern matching #

final result = divide(10, 2);

result.when(
  failure: (error) => print("Error: $error"),
  success: (value) => print("Result: $value"),
);

Using maybeWhen #

result.maybeWhen(
  success: (value) => print("Success with $value"),
  orElse: () => print("Something went wrong"),
);

📘 API #

sealed class Result<F, S> {
  const factory Result.failure(F failure) = Failure<F, S>;
  const factory Result.success(S success) = Success<F, S>;
}

• Result.failure(F) → represents a failure result.
• Result.success(S) → represents a successful result.

🛠️ Generated Code #

This package uses freezed. To generate code locally (for contributors):

flutter pub run build_runner build --delete-conflicting-outputs

📄 License #

MIT License

💰 Support #

If you find this project helpful, consider sponsoring me on GitHub 💖

🙌 Contributing #

Contributions, ideas, and pull requests are welcome. Let’s make flutter_resultable better together!