hlist.hs

{-# LANGUAGE TypeOperators, GADTs, DataKinds, KindSignatures #-}

import Data.Kind (Type)

data HList :: [Type] -> Type where
  Empty :: HList []
  HCons :: t -> HList ts -> HList (t ': ts)

myTuple2 :: HList '[Int, String] -- Analogous to (Int, String)
myTuple2 = HCons 2 (HCons "Hi!" Empty)

myTuple3 :: HList '[Bool, Int, Int -> Int] -- Analogous to (Bool, Int, Int -> Int)
myTuple3 = HCons True (HCons 1 (HCons (\x -> x + 2) Empty))