{-# LANGUAGE UndecidableInstances #-}

module Pandora.Paradigm.Primary.Transformer.Jet where

import Pandora.Pattern.Functor.Covariant (Covariant ((<$>)), (<$$>))
import Pandora.Pattern.Functor.Traversable (Traversable ((<<-)), (-<<-<<-))
import Pandora.Paradigm.Primary.Algebraic ((<-*-))

data Jet t a = Jet a (Jet t (t a))

instance Covariant (->) (->) t => Covariant (->) (->) (Jet t) where
	f <$> Jet x xs = Jet (f x) ((<$$>) @(->) @(->) f xs)

instance Traversable (->) (->) t => Traversable (->) (->) (Jet t) where
	f <<- Jet x xs = Jet <$> f x <-*- f -<<-<<- xs