{-# LANGUAGE CPP, MagicHash #-}
{-# LANGUAGE Trustworthy #-}

{-# OPTIONS_GHC -fno-warn-orphans #-}

-- |
-- Module      : Data.Text.Show
-- Copyright   : (c) 2009-2015 Bryan O'Sullivan
--
-- License     : BSD-style
-- Maintainer  : bos@serpentine.com
-- Stability   : experimental
-- Portability : GHC

module Data.Text.Show
    (
      singleton
    , unpack
    , unpackCString#
    ) where

import Control.Monad.ST (ST)
import Data.Text.Internal (Text(..), empty_, safe)
import Data.Text.Internal.Fusion (stream, unstream)
import Data.Text.Internal.Unsafe.Char (unsafeWrite)
import GHC.Prim (Addr#)
import qualified Data.Text.Array as A
import qualified Data.Text.Internal.Fusion.Common as S

import qualified GHC.CString as GHC

#if defined(ASSERTS)
import GHC.Stack (HasCallStack)
#endif

instance Show Text where
    showsPrec :: Int -> Text -> ShowS
showsPrec Int
p Text
ps String
r = Int -> String -> ShowS
forall a. Show a => Int -> a -> ShowS
showsPrec Int
p (Text -> String
unpack Text
ps) String
r

-- | /O(n)/ Convert a 'Text' into a 'String'.  Subject to fusion.
unpack ::
#if defined(ASSERTS)
  HasCallStack =>
#endif
  Text -> String
unpack :: Text -> String
unpack = Stream Char -> String
forall a. Stream a -> [a]
S.unstreamList (Stream Char -> String) -> (Text -> Stream Char) -> Text -> String
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Text -> Stream Char
stream
{-# INLINE [1] unpack #-}

-- | /O(n)/ Convert a literal string into a 'Text'.
--
-- This is exposed solely for people writing GHC rewrite rules.
--
-- @since 1.2.1.1
unpackCString# :: Addr# -> Text
unpackCString# :: Addr# -> Text
unpackCString# Addr#
addr# = Stream Char -> Text
unstream (Addr# -> Stream Char
S.streamCString# Addr#
addr#)
{-# NOINLINE unpackCString# #-}

{-# RULES "TEXT literal" [1] forall a.
    unstream (S.map safe (S.streamList (GHC.unpackCString# a)))
      = unpackCString# a #-}

{-# RULES "TEXT literal UTF8" [1] forall a.
    unstream (S.map safe (S.streamList (GHC.unpackCStringUtf8# a)))
      = unpackCString# a #-}

{-# RULES "TEXT empty literal" [1]
    unstream (S.map safe (S.streamList []))
      = empty_ #-}

{-# RULES "TEXT singleton literal" [1] forall a.
    unstream (S.map safe (S.streamList [a]))
      = singleton_ a #-}

-- | /O(1)/ Convert a character into a Text.  Subject to fusion.
-- Performs replacement on invalid scalar values.
singleton ::
#if defined(ASSERTS)
  HasCallStack =>
#endif
  Char -> Text
singleton :: Char -> Text
singleton = Stream Char -> Text
unstream (Stream Char -> Text) -> (Char -> Stream Char) -> Char -> Text
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Char -> Stream Char
S.singleton (Char -> Stream Char) -> (Char -> Char) -> Char -> Stream Char
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Char -> Char
safe
{-# INLINE [1] singleton #-}

{-# RULES "TEXT singleton" forall a.
    unstream (S.singleton (safe a))
      = singleton_ a #-}

-- This is intended to reduce inlining bloat.
singleton_ ::
#if defined(ASSERTS)
  HasCallStack =>
#endif
  Char -> Text
singleton_ :: Char -> Text
singleton_ Char
c = Array -> Int -> Int -> Text
Text ((forall s. ST s (MArray s)) -> Array
A.run forall s. ST s (MArray s)
x) Int
0 Int
len
  where x :: ST s (A.MArray s)
        x :: forall s. ST s (MArray s)
x = do MArray s
arr <- Int -> ST s (MArray s)
forall s. Int -> ST s (MArray s)
A.new Int
len
               Int
_ <- MArray s -> Int -> Char -> ST s Int
forall s. MArray s -> Int -> Char -> ST s Int
unsafeWrite MArray s
arr Int
0 Char
d
               MArray s -> ST s (MArray s)
forall (m :: * -> *) a. Monad m => a -> m a
return MArray s
arr
        len :: Int
len | Char
d Char -> Char -> Bool
forall a. Ord a => a -> a -> Bool
< Char
'\x10000' = Int
1
            | Bool
otherwise     = Int
2
        d :: Char
d = Char -> Char
safe Char
c
{-# NOINLINE singleton_ #-}