Utils.hs

{-# LANGUAGE TemplateHaskell, TypeOperators, FlexibleContexts, FlexibleInstances #-}

module Test.Utils where

import Data.Comp
import Data.Comp.Derive

import Data.Foldable


data Tree l e = Leaf l
              | UnNode l e
              | BinNode e l e
              | TerNode l e e e

data Pair a e = Pair a e

$(derive
  [makeFunctor, makeFoldable, makeShowF, makeEqF, makeArbitraryF]
  [''Tree, ''Pair])

$(derive
  [smartConstructors]
  [''Tree, ''Pair, ''Maybe])


type Sig1 = Maybe :+: Tree Int
type Sig2 = [] :+: Pair Int
type Sig = Maybe :+: Tree Int :+: [] :+: Pair Int


type SigP = Maybe :&: Int :+: Tree Int :&: Int :+: [] :&: Int :+: Pair Int :&: Int

instance EqF f => EqF (f :&: Int) where
    eqF (x :&: i) (y :&: j) = x `eqF` y && i == j

instance Show (a -> b) where
    show _ = "<function>"