– A curated list of awesome (functional) reactive programming stuff in JavaScript.
– Community with a friendly channel for JavaScript as well as many other channels about functional programming in general.
– Awesome resources on functional programming theory and learning materials.
A Learning Path for Functional Programming
– A ton of articles on functional programming, as well as a huge list of functional libraries for many programming languages.
– Compiles Clojure, a hosted Lisp with immutable persistent data structures, to JavaScript.
– Compiles a subset of Elixir, a dynamic, functional language designed for building scalable and maintainable applications, to JavaScript.
– A type-safe functional programming language for declaratively creating web browser-based graphical user interfaces. Implemented in Haskell.
Compiles F# to readable JavaScript.
– Haskell to JavaScript compiler, based on GHC.
Gleam is a typed, functional language that compiles to Erlang and JavaScript.
– A general purpose pure functional programming language with dependent types.
no BS JS
– Compiles OCaml bytecode to JavaScript, making it possible to run OCaml programs in the browser.
– Koka is a function-oriented programming language that seperates pure values from side-effecting computations with a familiar JavaScript like syntax.
– LiveScript has a straightforward mapping to JavaScript and allows you to write expressive code devoid of repetitive boilerplate.
– A small strongly typed programming language that compiles to JavaScript.
A multi-paradigm programming language with gradual and duck typing that targets PHP and JS.
– RacketScript aims to leverage both JavaScript and Racket's ecosystem, and make interoperability between them clean and smooth.
A Lisp that compiles to opinionated JavaScript on top of RamdaJS
– Reason is a new interface to OCaml, a highly expressive dialect of the ML language featuring type inference and static type checking.
– (previously known as Bucklescript) ReScript is a type-safe language that compiles to the highest quality of clean, readable and performant JavaScript code.
– Compiles Scala to JavaScript.
TypeScript is a typed superset of JavaScript that compiles to plain JavaScript.
– Functional tools that couldn’t be simpler. A dead simple functional utility belt, hand-crafted with love and attention. -TS.
– A modern and modular JavaScript utility library made to work well with vanilla JavaScript methods. -TS
– persistent and optionally immutable data tree with cursors.
– A tiny (2.7kb) functional programming library using native ES5/6 operations. -TS.
A practical functional programming library for promises.
– A property-based testing library for clearly specifying code invariants and behaviour.
– Super high-performance immutable data structures for modern JavaScript and TypeScript applications. +TS.
– Compose a new function from smaller functions.
Microscopic functional programming context aka dependency injection. +TS
– Sophisticated and functionally-minded async with advanced features: coroutines, promises, ES2015 iterables, fantasy-land. -TS.
– A collection of popular Algebraic Data Types with the main goal to curate and provide not only a common interface between each type, but also all of the helper functions needed to hit the ground running. -TS.
– Curry your functions using function bind syntax.
– Library for creating tagged constructors.
– A functional utility library for working with JavaScript dates. All functions in date-fp are pure, autocurried and will not mutate the date objects they are applied to.
– Functional Reactive State for JavaScript and TypeScript. DerivableJS enables you to make elegant declarative statements about how your bits of state are related. +TS.
Powerful dependency injection container for building modular apps. +TS
– A Fully-fledged functional effect system for typescript with a rich standard library. +TS
– Not a library, but a specification of the Monad laws for libraries to follow.
– Port of the Haskell package Data.Aviary.Birds. Everything for your combinatory needs.
– Common combinators.
– Composable, immutable getters and setters. (Profunctor lenses WIP)
– Iterator library with support for objects as iterables, lazy evaulation and`pipe()`; implements Traits (from Rust)/Type Classes (from Haskell) in JS. -TS.
– A Future library with included control utilities, high performance and great error messages.
– A simple function to curry a function.
– A functional library for CoffeeScript (and JavaScript) to facilitate functional composition and higher order functions.
– A standard library for functional programming in JavaScript. Typescript support expected mid-2020. -TS.
– Making the DOM functional.
JS/TS lightweight value-multimethod util
Typed functional programming in TypeScript. +CT, +TS.
A small library provides simple usages of basic FP & pattern-matching/sumtype & MonadIO/Rx & Optional for Javascript. -TS.
– FP library for JavaScript by Kyle Simpson (aka getify). Supports named-argument style methods.
– A collection of Free monads.
– An abstraction for managing asynchronous code in JS. Tasks are similar to Promises with the key difference that Tasks can represent a computation while Promises can represent only the results of a computation. Ships with Flow type definitions.
– A lightweight functional JavaScript library that facilitates currying and point-free / tacit programming.
– A collection of functions which aid in making non-functional libraries functional.
– An experiment in adding functional pattern matching to JavaScript. Experimental :triangularflagon_post:
– Funfix is a library of type classes and data types for Functional Programming in JavaScript, TypeScript and Flow. +CT, +TS.
A collection of functional utilities that could conceivably be part of a library like lodash/fp, but for some reason or other are not.
Lazy evaluation and concurrency. +TS
Natural 🌿 effect system that fits TypeScript; Write codes as you write **plain typescript code**.
Utilities for treating frozen JavaScript objects as persistent immutable collections
– Library for creating and manipulating lazy iterables using the ES2015 iteration protocols.
– Immer is a tiny package for immutable state based on copy-on-write mechanism. +TS.
– FantasyLand extensions for Immutable.js.
– High performance implementation of Immutable Sequence in JavaScript, based on Finger Trees.
– Immutable persistent data collections.
a rich toolset for working with iterables, both sync and async. +TS.
– Javascript parser combinator implementation inspired by the Haskell's Parsec
– An immutable date and time library that provides a simple, domain-driven and clean API based on the ISO8601 calendar.
Pipes with easy mocking, intended for huge amount of unit tests. +TS
A small utility library with a set of Algebraic Data Types and Helper functions to help you write code in a functional programming style in Javascript
– The full ECMAScript API done a functional way.
– A utility library with a lazy engine under the hood that strives to do as little work as possible while being as flexible as possible.
– Composable kmett style lenses.
A Lazy Functional Iteration Library Supporting Sync, Async, and Concurrent Iteration.
An extremely fast immutable list with a comprehensive functional API. Designed to seamlessly integrate with Ramda.
– An instance of Lodash with its methods wrapped to produce immutable, auto-curried, iteratee-first, data-last methods. +TS.
an async-first, opinionated, and functional language designed to have 100% compatibility with JavaScript engines
– A library that assists functional programming by providing a rich set of Monads and other useful functions. +CT, +TS.
– ClojureScript’s persistent data structures and supporting API from the comfort of vanilla JavaScript.
– Ultra-high performance reactive programming to help you compose asynchronous operations on streams of values and events without many of the hazards of side effects and mutable shared state.
– Lenses with dotty support.
This package contains a `Result` type that represents either success (`Ok`) or failure (`Err`).
Comprehensive Curry Library with Operator Curry, Curry from functions, Decurry and Infifnite Curries.
– Profunctor optics (Lens, Prism, iso).
An extremely small, intuitive and fast functional utility library for JavaScript -TS.
– Partial lenses is a comprehensive, high-performance optics library for JavaScript.
Arrays, Strings and things the functional way. A 640b functional library based on native methods. -TS.
Small, simple, easy FP data types for pragmatic and productive developers who need to ship reliable code fast. +CT, +TS.
– A functionally oriented utility library somewhat based off of Haskell's Prelude module. -TS.
Immutable persistent collections, functional constructs such as Option and Either, and combinators. Implemented in Typescript but supports javascript too. +CT, +TS.
Hardcore Functional Programming for JavaScript. -TS.
A powerful JavaScript functional programming toolset, including utility functions and abstract data structures.
Functional programming library for TypeScript focusing on ADTs. +CT, +TS.
– A type-safe, functional, performant, lawful, composable data structure that solves practical problems of effect-full code in node and browser. +TS
A faster alternative to Ramda in under 10kB.
Extended version of Rambda
– A practical functional library for JavaScript that is designed specifically for a functional programming style. A style that makes it easy to create functional pipelines and never mutates user data. +TS.
is a community-maintained extension of Ramda.
is set of utility point-free functions composed only from Ramda functions.
– :ram: :mag_right: Lens library built on Ramda.
Replace JSX in React with functions (currying, compositions and etc).
A function library roughly subsetting Ramda, but written in Typescript and thus more type-friendly. +TS.
Powerful pipes, that chain Promise and ADT like Maybe or Either from popular FP libraries. +TS
🏞 [a]synchronous functional syntax
Reactive state and effect management with RxJS. +TS
– Sanctuary makes it possible to write safe code without null checks. +CT, +TS.
– A lodash-inspired lens-like library for Javascript.
– Specification similar to Fantasy Land but based on static methods rather than instance methods.
A collection of popular monads (such as `Either` and `Maybe`) and the lazy iterator.
Grid Computing Framework, Network & Thread extension of TSTL, supporting RFC (Remote Function Call). +TS.
Tifi is a library for functional programming in TypeScript. It solves a problem of the existence of both `undefined` and `null`. Tifi is inspired by the OCaml/Reason utilities for the option data type. +CT, +TS.
– Immutability helpers with fast reads and acceptable writes.
– A functional user interface library with unidirectional dataflow and a virtual dom.
A library for safe, idiomatic null and error handling in TypeScript, with `Maybe` and `Result` types, supporting both a functional style and a more traditional method-call style
Fast, modern, and practical utility library for FP in TypeScript. (Uses a data-first approach like remeda, but is faster than remeda, ramda, rambda, and lodash/fp.)
Tiny TypeScript functional dependency injection, based on Node.js AsyncLocalStorage. +TS
TypeScript multimethods inspired by Clojure multimethods. +TS
The exhaustive Pattern Matching library for TypeScript, with smart type inference. Pattern Matching is a code-branching technique coming from FP languages.
C++ STL (Standard Template Library) is implemented in TypeScript. STL Containers, iterators, algorithms and functors, that following functional programming rule, are provided. +TS.
– A small JavaScript library for defining and using union types.
Super lightweight function that looks and behaves like a pipe operator.
– ☯ The simplest signal library possible
– A micro library that encourages functional programming by making native methods available as partially applied functions.
– A functional assertions library. If you prefer functional style APIs and practices in JavaScript, this library aims to solve this with functionally-oriented assertions that are lazy and monadic.
ESLint rules for functional programming
A pluggable runtime type checker and functional debugging tool that supports parametric and row polymorphism, implicit rank-2 types and algebraic data types via Scott Encoding.
– Runtime type checking for JS with Hindley Milner signatures.
– A four-part series introduction functional programming in JavaScript that gets you up to speed what all the hype about functional programming is all about.
– A walk through some practical use cases for specific monadic structures in JavaScript: use the `Maybe` monad to handle simple failure cases and model more complex scenarios with the `Either` monad or the `Validation` applicative functor.
A step by step guide to convert imperative JavaScript to more declarative, functional JavaScript.
A simple and understandable introduction of functional proramming in javascript.
Short and easy to understand article about implementing anonymous recursion in JavaScript.
Introduction to 2 easy monads in Javascript, Maybe & Either.
– A series that builds a “practical” web application with React and functional programming in JavaScript.
A series of articles on learning functional programming and compositional software techniques in JavaScript ES6+ from the ground up by @ericelliott.
– A puzzle game inspired by functional programming.
– A series of blog posts that reimplements various data structures in JavaScript to better understand their benefits and downsides.
. A modern introduction to programming using JavaScript. By Marijn Haverbeke (2014)
Design & refactoring tips for Promise-based Functional JavaScript. Key benefits include better readability, testability, and reusability. MIT.
Showcasing the similarities between F# and JavaScript
Practical applications of currying using Ramda.
– An introduction to Functional Programming Concepts in JavaScript. Uses the Ramda library to teach the concepts of composition, pointfree style, and functors through the simplest of examples.
– YouTube search app with ReactJS, Redux, and FP concepts
– Functional Programming learned through JavaScript.
– Step by step explanation of how to compose functions in javascript.
teaches how to create code that’s beautiful, safe, and simple to understand and test by using JavaScript’s functional programming support. By Michael Fogus (2013)
– A beginner-friendly introduction to Algebraic Data Types.
– Many articles on various aspects of functional programming in JavaScript by Gleb Bahmutov.
A complete introduction to functional programming in javascript made it easy by ES6.
A complete introduction to functional programming patterns by Chet Corcos with a lot of javascript examples.
teaches JavaScript developers functional techniques that will improve extensibility, modularity, reusability, testability, and performance. Through concrete examples and jargon-free explanations, this book teaches you how to apply functional programming to real-life development tasks. By Luis Atencio (2016)
A series by Mattias Petter Johansson, from the youtube channel FunFunFunction, that is specifically about popularization of functional programming in JavaScript.
Discover functional programming with Typescript and create a library like fp-ts alongside Sahand Javid in this beginner-friendly YouTube playlist.
– Jargon from the functional programming world explained in JavaScript.
– Learn about practical use cases for functors, applicatives, and monads.
Practical code examples to learn functional programming concepts like pure function, immutability, first-class entities, and higher order functions
– Another introduction to Functional Programming in JavaScript with a focus on three key themes: computation as the application of functions, statelessness, avoiding side effects.
– A functional frontend framework. Based on Ramda + union-type-js + Flyd + Snabbdom
– The goal of this workshop is to create realistic problems that can be solved using terse, vanilla, idiomatic JavaScript to teach fundamental functional programming features of JavaScript.
– This book explores the core principles of functional programming (FP) that can be applied to JavaScript. But what makes this book different is that it approaches these principles without all the heavy terminology.
Explaining functors concept using JavaScript.
teaches functional programming from first principles. It uses JavaScript for all code examples and it uses real-world scenarios. By Eric Normand (2019)
– Learn to apply techniques from the forefront of computer science research to solve practical problems in Javascript. Discover functional programming and see it demonstrated step-by-step with how to build an example web app using abstract interfaces like Monads, Functors, Monoids and Applicatives. (commercial)
– Underscore.js claims to be a functional programming library, but is it really?
Yet another Holdem Evaluator with Ramda functional style
Learn about functional data structures and their uses in this overview of Facebook's popular library for JavaScript: Immutable.js.
, the “Six” edition. Starts with as little as possible about functions – but no less! – and builds up towards powerful combinators and decorators. A foundational book. By Reginald Braithwaite (2016)
– Learn to reason about your JavaScript code with type thinking. Algebraic Data Types are introduced as a conceptual basis to reason about program entities.
Seth House explains how ADTs (Algebraic Data Types) can be useful to JavaScript developers.
– Use four new features of ES6 – iterables, generators, fat arrows, and for-of – in conjunction with higher-order functions, function composition, and lazy evaluation, to write cleaner and more modular JavaScript.
– A series of interactive exercises introducing five basic ingredients of functional (reactive) programming: the `map`, `filter`, `concatAll`, `reduce`, and `zip` functions.
A simple introduction by @ericelliott to functional principles and vocabulary.
– An introduction to the Monad design pattern in JavaScript.
– This is a book on the functional paradigm in general using the world’s most popular functional programming language: JavaScript. It’s a practical introduction that builds up intuition through real-world examples. Strongly recommended. By Brian Lonsdorf (2016)
– Christian Johansen will show you how you can significantly up your game by leaving loops behind and embracing functions as the primary unit of abstraction.
a no-frills functional programming library and a online course based on it
Easy to understand, with some examples, introduction to Functional Programming in Javascript and Elm.
– A short overview of how to write reusable and declarative code using currying.
– To those not used to functional programming, Ramda seems to serve no purpose whatsoever. However, it does offer a different style of coding, a style that’s taken for granted in purely functional programming languages: Ramda makes it simple for you to build complex logic through functional composition.
Loops are one of the first constructs that junior programmers learn, but they can pose many potential issues in the software development process, and could be avoided in many cases.