typelevel/spotted-leopards

Proof of concept for a cats-like library built using Dotty features

{
  "createdAt": "2019-05-29T20:16:43Z",
  "defaultBranch": "main",
  "description": "Proof of concept for a cats-like library built using Dotty features",
  "fullName": "typelevel/spotted-leopards",
  "homepage": null,
  "language": "Scala",
  "name": "spotted-leopards",
  "pushedAt": "2024-06-01T14:41:40Z",
  "stargazersCount": 117,
  "topics": [
    "functional-programming",
    "scala",
    "typelevel"
  ],
  "updatedAt": "2024-10-25T10:44:58Z",
  "url": "https://github.com/typelevel/spotted-leopards"
}

Spotted Leopards

Spotted Leopards = Dotty + Cats

Spotted Leopards is a proof of concept for a cats-like library built using Dotty features, with no concern for source compatibility with the existing Cats library. This project has a few goals:

explore how new language features in Dotty could be used to improve the encodings of functional type classes and related data types, perhaps informing future Cats / Dotty roadmap
provide feedback on Dotty features from the perspective of cats library authors
provide a code base of significant size that can be used for learning and exploring Dotty

In short, this project is an experiment only and will not in any way become a library that should be used for real work. This project is NOT a preview of a future Cats version. Rather, it provides a way to explore the design space of the Dotty language features without the constraints of source compatibility and cross-building expected of Cats proper.

Getting Started

To get started, launch sbt console and run the following:

scala> import leopards.{*, given} // Import various types like Monad and OptionT and type class instances

scala> Some(1).map2(Some(2), _ + _)
val res0: Option[Int] = Some(3)

scala> OptionT.fromOption[List, Int]!(res0)
val res1: leopards.OptionT[List, Int] = List(Some(3))