Scale back changes to ShortByteString to pattern synonym only

haskell · Nov 25, 2021 · ac24f1b · ac24f1b
1 parent 7aba6b4
commit ac24f1b
Showing 1 changed file with 7 additions and 23 deletions.
diff --git a/Data/ByteString/Short/Internal.hs b/Data/ByteString/Short/Internal.hs
@@ -6,10 +6,6 @@
 {-# LANGUAGE Unsafe #-}
 {-# LANGUAGE TemplateHaskellQuotes #-}
 {-# LANGUAGE PatternSynonyms #-}
-{-# LANGUAGE GeneralizedNewtypeDeriving #-}
-#if MIN_VERSION_base(4,10,0)
-{-# LANGUAGE DerivingStrategies #-}
-#endif
 
 {-# OPTIONS_HADDOCK not-home #-}
 
@@ -60,19 +56,17 @@ module Data.ByteString.Short.Internal (
 
 #if BYTEARRAY_IN_BASE
 import Data.Array.Byte
-import Data.Semigroup   (Semigroup)
-#else
-import Data.Typeable    (Typeable)
-import Data.Semigroup   (Semigroup((<>)))
-import Control.DeepSeq  (NFData(..))
 #endif
 
 import Data.ByteString.Internal (ByteString(..), accursedUnutterablePerformIO)
 import qualified Data.ByteString.Internal as BS
 
+import Data.Typeable    (Typeable)
 import Data.Data        (Data(..), mkNoRepType)
+import Data.Semigroup   (Semigroup((<>)))
 import Data.Monoid      (Monoid(..))
 import Data.String      (IsString(..))
+import Control.DeepSeq  (NFData(..))
 import qualified Data.List as List (length)
 import Foreign.C.String (CString, CStringLen)
 import Foreign.C.Types  (CSize(..), CInt(..))
@@ -128,7 +122,7 @@ import qualified Language.Haskell.TH.Syntax as TH
 --
 #if BYTEARRAY_IN_BASE
 newtype ShortByteString = ShortByteString { unShortByteString :: ByteArray }
-  deriving newtype (Eq, Semigroup, Monoid)
+    deriving Typeable
 
 pattern SBS :: ByteArray# -> ShortByteString
 pattern SBS x = ShortByteString (ByteArray x)
@@ -165,16 +159,14 @@ instance TH.Lift ShortByteString where
 -- the 0--3 trailing bytes undefined. This means we can use word-sized writes,
 -- but we have to be careful with reads, see equateBytes and compareBytes below.
 
-#if !BYTEARRAY_IN_BASE
+
 instance Eq ShortByteString where
     (==)    = equateBytes
-#endif
 
 -- | Lexicographic order.
 instance Ord ShortByteString where
     compare = compareBytes
 
-#if !BYTEARRAY_IN_BASE
 instance Semigroup ShortByteString where
     (<>)    = append
 
@@ -185,7 +177,6 @@ instance Monoid ShortByteString where
 
 instance NFData ShortByteString where
     rnf SBS{} = ()
-#endif
 
 instance Show ShortByteString where
     showsPrec p ps r = showsPrec p (unpackChars ps) r
@@ -196,13 +187,8 @@ instance Read ShortByteString where
 -- | @since 0.10.12.0
 instance GHC.Exts.IsList ShortByteString where
   type Item ShortByteString = Word8
-#if BYTEARRAY_IN_BASE
-  fromList = ShortByteString . GHC.Exts.fromList
-  toList   = GHC.Exts.toList . unShortByteString
-#else
   fromList = packBytes
   toList   = unpackBytes
-#endif
 
 -- | Beware: 'fromString' truncates multi-byte characters to octets.
 -- e.g. "枯朶に烏のとまりけり秋の暮" becomes �6k�nh~�Q��n�
@@ -430,15 +416,13 @@ unpackAppendBytesStrict !sbs off len = go (off-1) (off-1 + len)
 ------------------------------------------------------------------------
 -- Eq and Ord implementations
 
-#if !BYTEARRAY_IN_BASE
 equateBytes :: ShortByteString -> ShortByteString -> Bool
 equateBytes sbs1 sbs2 =
     let !len1 = length sbs1
         !len2 = length sbs2
      in len1 == len2
      && 0 == accursedUnutterablePerformIO
                (memcmp_ByteArray (asBA sbs1) (asBA sbs2) len1)
-#endif
 
 compareBytes :: ShortByteString -> ShortByteString -> Ordering
 compareBytes sbs1 sbs2 =
@@ -453,10 +437,10 @@ compareBytes sbs1 sbs2 =
             | len2 < len1 -> GT
             | otherwise   -> EQ
 
+
 ------------------------------------------------------------------------
 -- Appending and concatenation
 
-#if !BYTEARRAY_IN_BASE
 append :: ShortByteString -> ShortByteString -> ShortByteString
 append src1 src2 =
   let !len1 = length src1
@@ -478,7 +462,7 @@ concat sbss =
       let !len = length src
       copyByteArray (asBA src) 0 dst off len
       copy dst (off + len) sbss
-#endif
+
 
 ------------------------------------------------------------------------
 -- Exported low level operations