{-# 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 () where
#if MIN_VERSION_base(4,6,0)
import Prelude ()
import Prelude.Compat
import TextShow.Classes (TextShow(..))
import TextShow.Data.Integral ()
# if MIN_VERSION_base(4,7,0)
import GHC.TypeLits (SomeNat(..), SomeSymbol(..), natVal, symbolVal)
import TextShow.Data.Char ()
# else
import Data.Text.Lazy.Builder (singleton)
import GHC.TypeLits (IsEven(..), IsZero(..), Kind, Sing, SingE(fromSing))
# endif
# if MIN_VERSION_base(4,7,0)
instance TextShow SomeNat where
showbPrec :: Int -> SomeNat -> Builder
showbPrec Int
p (SomeNat Proxy n
x) = Int -> Integer -> Builder
forall a. TextShow a => Int -> a -> Builder
showbPrec Int
p (Integer -> Builder) -> Integer -> Builder
forall a b. (a -> b) -> a -> b
$ Proxy n -> Integer
forall (n :: Nat) (proxy :: Nat -> *).
KnownNat n =>
proxy n -> Integer
natVal Proxy n
x
{-# INLINE showbPrec #-}
instance TextShow SomeSymbol where
showb :: SomeSymbol -> Builder
showb (SomeSymbol Proxy n
x) = [Char] -> Builder
forall a. TextShow a => [a] -> Builder
showbList ([Char] -> Builder) -> [Char] -> Builder
forall a b. (a -> b) -> a -> b
$ Proxy n -> [Char]
forall (n :: Symbol) (proxy :: Symbol -> *).
KnownSymbol n =>
proxy n -> [Char]
symbolVal Proxy n
x
{-# INLINE showb #-}
# else
instance TextShow (IsEven n) where
showb IsEvenZero = singleton '0'
showb (IsEven x) = "(2 * " <> showb x <> singleton ')'
showb (IsOdd x) = "(2 * " <> showb x <> " + 1)"
{-# INLINE showb #-}
instance TextShow (IsZero n) where
showb IsZero = singleton '0'
showb (IsSucc n) = singleton '(' <> showb n <> " + 1)"
{-# INLINE showb #-}
instance (SingE (Kind :: k) rep, TextShow rep) => TextShow (Sing (a :: k)) where
showbPrec p = showbPrec p . fromSing
{-# INLINE showbPrec #-}
# endif
#endif