@fp-ts/core

Functional programming in TypeScript

Typed functional programming in TypeScript

This project represents the next major iteration of fp-ts and it's objective is a reconciliation with @effect in order to unify the ecosystems.

The @effect project will reduce it's scope to simply being an effect system and will delegate to fp-ts org all the lower level abstractions such as typeclasses and common data structures.

The objective of the fp-ts org in github and in npm (@fp-ts) is to simplify structure and management of the project, have smaller and better scoped packages.

Our "current" idea (that is well open for changes) is for fp-ts org to have:

• The @fp-ts/core library features a new implementation of the Higher Kinded Type (HKT) pattern, including common typeclasses such as Monad and widely-used data types like Option, Either, and ReadonlyArray
• @fp-ts/schema offers schema validation with static type inference, including decoders for data structures in @fp-ts/core and @effect/data
• @fp-ts/optic provides optics for structures in both @fp-ts/core and @effect/data

For those using fp-ts v2 and its ecosystem, roughly these are the equivalents:

• fp-ts -> @fp-ts/core + @effect/* packages
• io-ts -> @fp-ts/schema
• monocle-ts -> @fp-ts/optic

Note that @fp-ts/core will not contain any effect system (e.g. Task, TaskEither, ReaderTaskEither) since the handling of effects is entirely delegated to the packages contained in @effect/*.

Installation

To install the alpha version:

npm install @fp-ts/core

Documentation

• Typeclass overview
• Data overview
• The Option data type
• The Either data type
• API Reference

License

The MIT License (MIT)