gunzip/fp-ts

Functional programming in TypeScript

Inspired by

• PureScript
• fantasy-land
• static-land
• Scala

Installation

To install the stable version:

npm install --save fp-ts

TypeScript compatibility

The stable version is tested against TypeScript 2.7.x, but should run with TypeScript 2.2.2+ too

Technical overview

The idea (faking higher kinded types in TypeScript) is based on

• Lightweight higher-kinded polymorphism
• elm-brands
• Higher kinded types in TypeScript, static and fantasy land
• flow-static-land

Ecosystem

• io-ts - TypeScript compatible runtime type system for IO validation
• monocle-ts - Functional optics: a (partial) porting of scala monocle to TypeScript
• newtype-ts - Implementation of newtypes in TypeScript
• logging-ts - Composable loggers for TypeScript
• fp-ts-routing - A type-safe bidirectional routing library for TypeScript
• parser-ts - String parser combinators for TypeScript
• remote-data-ts - RemoteData type (check this article)

Bindings

• fp-ts-rxjs - fp-ts bindings for RxJS
• fp-ts-fluture - fp-ts bindings for Fluture

Documentation

• API

Internals

• How HKT, URI2HKT, URIS and Type work

Examples

• Free monad
• MTL-style
• OptionT monad transformer
  • ArrayOption
  • TaskOption
• EitherT monad transformer
  • EitherOption
• StateT monad transformer
  • StateIO
  • StateTaskEither
• ReaderT monad transformer
  • ReaderIO
• Applicative composition
  • TaskValidation
• Type safe finite state machines with IxIO
• Moore machines
• Debugging with Trace
• fantas-eel-and-specification - Code for the Fantas, Eel, and Specification blog series on functional programming by Tom Harding

Note. You can run the examples using ts-node with tsconfig-paths

$ cd examples
$ ts-node -r tsconfig-paths/register debugging-with-Trace.ts

License

The MIT License (MIT)