    {-# LANGUAGE CPP                  #-}

    #if MIN_VERSION_base(4,6,0)
    # if !(MIN_VERSION_base(4,7,0))
    {-# LANGUAGE FlexibleContexts     #-}
    {-# LANGUAGE GADTs                #-}
    {-# LANGUAGE KindSignatures       #-}
    {-# LANGUAGE OverloadedStrings    #-}
    {-# LANGUAGE PolyKinds            #-}
    {-# LANGUAGE UndecidableInstances #-}
    # endif

    {-# OPTIONS_GHC -fno-warn-orphans #-}
    #endif
    {-|
    Module:      TextShow.GHC.TypeLits
    Copyright:   (C) 2014-2015 Ryan Scott
    License:     BSD-style (see the file LICENSE)
    Maintainer:  Ryan Scott
    Stability:   Provisional
    Portability: GHC

    Monomorphic 'TextShow' functions for data types in the @GHC.TypeLits@ module.
    This module only exports functions if using @base-4.6.0.0@ or later.

    /Since: 2/
    -}
    module TextShow.GHC.TypeLits (
    #if MIN_VERSION_base(4,7,0)
          showbSomeNatPrec
        , showbSomeSymbol
        ) where
    #elif MIN_VERSION_base(4,6,0)
          showbIsEven
        , showbIsZero
        , showbSingPrec
        ) where
    #else
        ) where
    #endif

    #if MIN_VERSION_base(4,6,0)

    import Data.Text.Lazy.Builder (Builder)
    import TextShow.Classes (TextShow(showb, showbPrec))

    # if MIN_VERSION_base(4,7,0)
    import GHC.TypeLits (SomeNat(..), SomeSymbol(..), natVal, symbolVal)
    import TextShow.Data.Char (showbString)
    import TextShow.Data.Integral (showbIntegerPrec)
    # else
    import Data.Monoid.Compat ((<>))
    import Data.Text.Lazy.Builder (singleton)
    import GHC.TypeLits (IsEven(..), IsZero(..), Kind, Sing, SingE(fromSing))
    import TextShow.Data.Integral ()
    # endif

    # if MIN_VERSION_base(4,7,0)
    -- | Convert a 'SomeNat' value to a 'Builder' with the given precedence.
    -- This function is only available with @base-4.7.0.0@ or later.
    --
    -- /Since: 2/
    showbSomeNatPrec :: Int -> SomeNat -> Builder
    showbSomeNatPrec p (SomeNat x) = showbIntegerPrec p $ natVal x
    {-# INLINE showbSomeNatPrec #-}

    -- | Convert a 'SomeSymbol' value to a 'Builder' with the given precedence.
    -- This function is only available with @base-4.7.0.0@ or later.
    --
    -- /Since: 2/
    showbSomeSymbol :: SomeSymbol -> Builder
    showbSomeSymbol (SomeSymbol x) = showbString $ symbolVal x
    {-# INLINE showbSomeSymbol #-}
    # else
    -- | Convert an 'IsEven' value to a 'Builder'.
    -- This function is only available with @base-4.6@.
    --
    -- /Since: 2/
    showbIsEven :: IsEven n -> Builder
    showbIsEven IsEvenZero = singleton '0'
    showbIsEven (IsEven x) = "(2 * " <> showb x <> singleton ')'
    showbIsEven (IsOdd  x) = "(2 * " <> showb x <> " + 1)"
    {-# INLINE showbIsEven #-}

    -- | Convert an 'IsZero' value to a 'Builder'.
    -- This function is only available with @base-4.6@.
    --
    -- /Since: 2/
    showbIsZero :: IsZero n -> Builder
    showbIsZero IsZero     = singleton '0'
    showbIsZero (IsSucc n) = singleton '(' <> showb n <> " + 1)"
    {-# INLINE showbIsZero #-}

    -- | Convert a 'Sing' value to a 'Builder' with the given precedence.
    --
    -- /Since: 2/
    showbSingPrec :: (SingE (Kind :: k) rep, TextShow rep) => Int -> Sing (a :: k) -> Builder
    showbSingPrec p = showbPrec p . fromSing
    {-# INLINE showbSingPrec #-}
    # endif

    # if MIN_VERSION_base(4,7,0)
    instance TextShow SomeNat where
        showbPrec = showbSomeNatPrec
        {-# INLINE showbPrec #-}

    instance TextShow SomeSymbol where
        showb = showbSomeSymbol
        {-# INLINE showb #-}
    # else
    instance TextShow (IsEven n) where
        showb = showbIsEven
        {-# INLINE showb #-}

    instance TextShow (IsZero n) where
        showb = showbIsZero
        {-# INLINE showb #-}

    instance (SingE (Kind :: k) rep, TextShow rep) => TextShow (Sing (a :: k)) where
        showbPrec = showbSingPrec
        {-# INLINE showbPrec #-}
    # endif

    #endif