Hackett - Programming language

Hackett is an open source programming language created in 2017 by Alexis King.

Source code:

git clone https://github.com/lexi-lambda/hackett

#761on PLDB

7Years Old

Hackett is an attempt to implement a Haskell-like language with support for Racket’s macro system, built using the techniques described in the paper Type Systems as Macros.

Hackett website
Hackett is developed on GitHub and has 1,094 stars
Hackett first developed in https://github.com/lexi-lambda/hackett/issues

Example from the web:

#lang hackett

(data (Maybe a)
  Nothing
  (Just a))

(def x : Integer
  (let ([y 3]
        [z 7])
    {y + z}))

(class (Show a)
  [show : {a -> String}])

(instance (forall [a] (Show a) => (Show (Maybe a)))
  [show (λ* [[(Just x)] {"(Just " ++ (show x) ++ ")"}]
            [[Nothing ] "Nothing"])])