keksnicoh

-- this is using template haskell to reduce boilerplate
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE GADTs #-}
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE StandaloneKindSignatures #-}
{-# LANGUAGE KindSignatures #-}
{-# LANGUAGE TemplateHaskell #-}

module SigmaCustomSing where

keksnicoh

{-# LANGUAGE LambdaCase #-}
{-# LANGUAGE RankNTypes #-}
{-# LANGUAGE TypeApplications #-}

module Test where

import Control.Applicative (Alternative (..), Applicative (liftA2))
import Control.Monad (MonadPlus (..), guard)
import Data.Char (isDigit, ord, toLower)