@effect/io

What is @effect/io?

@effect/io is a library for building robust, type-safe, and composable applications in TypeScript. It provides a powerful set of tools for managing side effects, concurrency, and error handling in a functional programming style.

What are @effect/io's main functionalities?

Effect Management

This feature allows you to create and manage effects, which are computations that can produce values or perform side effects. The example demonstrates creating a simple effect that succeeds with the value 42 and then running it.

const { Effect } = require('@effect/io');

const effect = Effect.succeed(42);
effect.run().then(console.log); // Outputs: 42

Error Handling

This feature provides robust error handling capabilities. The example shows how to create an effect that fails with an error and how to handle that error when running the effect.

const { Effect } = require('@effect/io');

const effect = Effect.fail(new Error('Something went wrong'));
effect.run().catch(console.error); // Outputs: Error: Something went wrong

Concurrency

This feature allows you to compose and run effects concurrently. The example demonstrates combining two effects that succeed with values 1 and 2, respectively, and running them together.

const { Effect } = require('@effect/io');

const effect1 = Effect.succeed(1);
const effect2 = Effect.succeed(2);
const combinedEffect = Effect.zip(effect1, effect2);
combinedEffect.run().then(console.log); // Outputs: [1, 2]

Resource Management

This feature provides tools for managing resources that need to be acquired and released. The example shows how to create a resource, use it in an effect, and ensure that cleanup is performed afterward.

const { Effect, Resource } = require('@effect/io');

const resource = Resource.make(
  Effect.succeed('resource'),
  () => Effect.succeed(console.log('cleanup'))
);

resource.use(res => Effect.succeed(console.log(res))).run(); // Outputs: 'resource' and then 'cleanup'

Other packages similar to @effect/io

rxjs

RxJS is a library for reactive programming using Observables, to make it easier to compose asynchronous or callback-based code. Compared to @effect/io, RxJS focuses more on reactive streams and less on effect management and resource handling.

fp-ts

fp-ts is a library for functional programming in TypeScript. It provides many of the same functional programming constructs as @effect/io, but it is more focused on providing a comprehensive suite of functional programming utilities rather than specifically managing effects and concurrency.

redux-saga

redux-saga is a library that aims to make application side effects (e.g., asynchronous actions) easier to manage, more efficient to execute, and better at handling failures. It uses generator functions to handle side effects in a Redux application. While it shares some similarities with @effect/io in terms of managing side effects, it is more tightly coupled with Redux and less general-purpose.

README

WIP.

Effect Docs: https://www.effect.website
Module Docs: https://effect-ts.github.io/io

Contributing Guidelines

Thank you for considering contributing to our project! Here are some guidelines to help you get started:

Reporting Bugs

If you have found a bug, please open an issue on our issue tracker and provide as much detail as possible. This should include:

• A clear and concise description of the problem
• Steps to reproduce the problem
• The expected behavior
• The actual behavior
• Any relevant error messages or logs

Suggesting Enhancements

If you have an idea for an enhancement or a new feature, please open an issue on our issue tracker and provide as much detail as possible. This should include:

• A clear and concise description of the enhancement or feature
• Any potential benefits or use cases
• Any potential drawbacks or trade-offs

Pull Requests

We welcome contributions via pull requests! Here are some guidelines to help you get started:

1. Fork the repository and clone it to your local machine.
2. Create a new branch for your changes: git checkout -b my-new-feature
3. Install dependencies: pnpm install (pnpm@8.x)
4. Make your changes and add tests if applicable.
5. Run the tests: pnpm test
6. Commit your changes: git commit -am 'Add some feature'
7. Push your changes to your fork: git push origin my-new-feature
8. Open a pull request against our main branch.

Pull Request Guidelines

• Please make sure your changes are consistent with the project's existing style and conventions.
• Please write clear commit messages and include a summary of your changes in the pull request description.
• Please make sure all tests pass and add new tests as necessary.
• If your change requires documentation, please update the relevant documentation.
• Please be patient! We will do our best to review your pull request as soon as possible.

License

By contributing to this project, you agree that your contributions will be licensed under the project's MIT License.

Changelog

0.40.0

Minor Changes

• #648 01723b6 Thanks @mikearnaldi! - Make Cooperative Yielding Scheduler-Aware

• #646 ec796c0 Thanks @mikearnaldi! - Fix runtimeFlags naming

• #649 40dc950 Thanks @mikearnaldi! - Reintroduce max number of ops via fiber ref

• #649 40dc950 Thanks @mikearnaldi! - Improve fiber naming

Patch Changes

• #651 403bef3 Thanks @tim-smart! - add concurrency and batching to replicateEffect

• #644 d8d1e3f Thanks @mikearnaldi! - Fix improper scope signatures