Steps.hs

{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE TypeOperators #-}
{-# OPTIONS_GHC -Wall #-}

{- | The name @steps@, targeting @['System.FilePather.Step.Step']@: the steps of a trail, nearest first.

Any value of the target type has the name, as the identity.

@since 0.8.0.0
-}
module System.FilePather.Name.Steps (
  StepsLike (..),
) where

import Control.Lens (Optic)
import System.FilePather.Step (Step)

{- | A field or a constructor named @steps@.

@since 0.8.0.0
-}
class StepsLike p f x x' where
  steps ::
    Optic p f x x' [Step] [Step]

{- | Identity

@since 0.8.0.0
-}
instance (x' ~ [Step]) => StepsLike p f [Step] x' where
  steps =
    id
  {-# INLINE steps #-}