any_of

A Dart package that provides utility classes for working with discriminated unions known as "any-of" types. These types allow you to represent a value that can be one of several possible options.

Overview

The any_of package simplifies working with any-of types in your Dart applications. It provides the following classes:

  • Doublet: Represents a pair of values where one of the values is selected.
  • Triplet: Represents a triplet of values where one of the values is selected.
  • Quartet: ---
  • ... Up to Nonet

These classes provide convenient methods for mapping, handling different cases, and ensuring the presence of a value.

Installation

To use this package, add any_of as a dependency in your pubspec.yaml file:

dependencies:
  any_of: <latest>

Usage

Importing the package

import 'package:any_of/any_of.dart';

Doublet Usage

A Doublet represents a pair of values where one value is selected. Here's an example of how to create and work with a Doublet:


class TestDoubletClass extends Doublet<String, NotFound> {
  TestDoubletClass.success(super.value) : super.first();
  TestDoubletClass.notFound(super.value) : super.second();
}

// or

class TestDoubletClass extends Doublet<String, NotFound> {
  TestDoubletClass.success(String value) : super.first(value);
  TestDoubletClass.notFound(NotFound value) : super.second(value);
}

// or

class TestDoubletClass extends Doublet<String, NotFound> {
  TestDoubletClass.success() : super.first('Default String');
  TestDoubletClass.notFound(NotFound value) : super.second(value);
}

void main() {
  var response = TestDoubletClass.success('Success');

  if (response.isFirst) {
    print(response.first);  // Output: 'Success'
  } else if (response.isSecond) {
    print(response.second); // Is not executed
  }
}

For more detailed examples and usage instructions, please refer to the API Reference section.

API Reference

Doublet Class

A class that represents a pair of values where one of the values is selected.

Constructors

  • Doublet.first(T0 value): Constructs a Doublet instance with the first value selected.
  • Doublet.second(T1 value): Constructs a Doublet instance with the second value selected.

Properties

  • isFirst: Returns true if the first value is selected, otherwise false.
  • isSecond: Returns true if the second value is selected, otherwise false.
  • first: Returns the first value. Throws a TypeError if the first value is not selected.
  • second: Returns the second value. Throws a TypeError if the second value is not selected.
  • props: A list of the first and second values.

Methods

  • map<R>({required R Function(T0) first, required R Function(T1) second}): Applies a mapping function to the selected value and returns the result. Throws an Exception if no value is selected.
  • on<R>({required void Function(T0) first, required void Function(T1) second}): Executes a callback function based on the selected value. Throws an Exception if no value is selected.
  • ifType<R>({required void Function(R) callback}): Executes a callback function if the selected value matches the specified type. Does nothing if no value is selected or if the selected value does not match the type.

Triplet class

The same Constructors, Properties and Methods on Doublet are applied to Triplet, but with an extra value. This is equivalent up until Nonet.

The classes are:

  • Doublet
  • Triplet
  • Quartet
  • Quintet
  • Sextet
  • Septet
  • Octet
  • Nonet

Built-In response types

As most applications share the same errors, there are some built-in response types you can use as an indicator what went wrong. Right now there are:

  • ApiError
  • BadRequest
  • Conflict
  • InternalError
  • NetworkError
  • NotFound
  • NotImplemented
  • PermissionDenied
  • SerializationError
  • ServiceUnavailable
  • Success
  • TimedOut
  • Unauthorized
  • UnknownError
  • ValidationFailed

But you can return any type as response, such as bool, String, int, etc. or any other custom class. The above response types extend from AnyOfType but this is not a must.

Contributing

Contributions are welcome! If you encounter any issues or have suggestions for improvements, please create an issue on the GitHub repository. Pull requests are also encouraged.

Before contributing, please review the contribution guidelines and ensure adherence to the code of conduct.

Changelog

See the CHANGELOG for a complete list of changes and releases in the package.

License

MIT

Libraries

any_of