{-# LANGUAGE EmptyDataDecls #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE GADTs #-}
{-# LANGUAGE KindSignatures #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE TemplateHaskell #-}
{-# LANGUAGE TypeFamilies #-}
module Tree where

import Generics.MultiRec
import Generics.MultiRec.TH.Alt
import Data.Tree

data TheFam :: (* -> *) where
              Tree_Int   :: TheFam   (Tree Int)
              Forest_Int :: TheFam (Forest Int)
              Pair       :: TheFam (Tree Int, Tree Int)
                           
$(deriveEverything
  (DerivOptions
   [ ( [t| Tree   Int |]          , "Tree_Int" )
   , ( [t| Forest Int |]          , "Forest_Int" )
   , ( [t| (Tree Int, Tree Int) |], "Pair" )
   ]
   "TheFam"
   (\t c -> "CONSTRUCTOR_" ++ t ++ "_" ++ c)
   "ThePF"
   True
  )
 )

type instance PF TheFam = ThePF