{-# LANGUAGE NoImplicitPrelude #-} {-# LANGUAGE FlexibleInstances #-} module Data.Aviation.Units.Litres( Litres(litres) ) where import Control.Category(id) import Control.Lens(Iso') import Prelude(Rational) class Litres a where litres :: Iso' Rational a instance Litres Rational where litres :: p Rational (f Rational) -> p Rational (f Rational) litres = p Rational (f Rational) -> p Rational (f Rational) forall k (cat :: k -> k -> *) (a :: k). Category cat => cat a a id