Scale back changes to ShortByteString to pattern synonym only

haskell · Mar 22, 2022 · 8b962e8 · 8b962e8
1 parent e51ede3
commit 8b962e8
Showing 1 changed file with 9 additions and 22 deletions.
diff --git a/Data/ByteString/Short/Internal.hs b/Data/ByteString/Short/Internal.hs
@@ -2,7 +2,6 @@
 {-# LANGUAGE CPP                      #-}
 {-# LANGUAGE DeriveDataTypeable       #-}
 {-# LANGUAGE ForeignFunctionInterface #-}
-{-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE LambdaCase               #-}
 {-# LANGUAGE MagicHash                #-}
 {-# LANGUAGE MultiWayIf               #-}
@@ -16,10 +15,6 @@
 {-# LANGUAGE UnliftedFFITypes         #-}
 {-# LANGUAGE Unsafe                   #-}
 
-#if MIN_VERSION_base(4,10,0)
-{-# LANGUAGE DerivingStrategies #-}
-#endif
-
 {-# OPTIONS_GHC -fno-warn-name-shadowing -fexpose-all-unfoldings #-}
 {-# OPTIONS_HADDOCK not-home #-}
 
@@ -191,10 +186,16 @@ import Data.Data
   )
 import Data.Monoid
   ( Monoid(..) )
+import Data.Semigroup
+  ( Semigroup((<>)) )
 import Data.String
   ( IsString(..) )
+import Data.Typeable
+  ( Typeable )
 import Control.Applicative
   ( pure )
+import Control.DeepSeq
+  ( NFData(..) )
 import Control.Exception
   ( assert )
 import Control.Monad
@@ -275,11 +276,6 @@ import Prelude
 
 #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 qualified Data.ByteString.Internal as BS
@@ -305,7 +301,7 @@ 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)
@@ -342,16 +338,14 @@ 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
 
@@ -362,7 +356,6 @@ instance Monoid ShortByteString where
 
 instance NFData ShortByteString where
     rnf SBS{} = ()
-#endif
 
 instance Show ShortByteString where
     showsPrec p ps r = showsPrec p (unpackChars ps) r
@@ -373,13 +366,8 @@ 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�
@@ -666,14 +654,12 @@ 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 == compareByteArrays (asBA sbs1) (asBA sbs2) len1
-#endif
 
 compareBytes :: ShortByteString -> ShortByteString -> Ordering
 compareBytes sbs1 sbs2 =
@@ -687,6 +673,7 @@ compareBytes sbs1 sbs2 =
             | len2 < len1 -> GT
             | otherwise   -> EQ
 
+
 ------------------------------------------------------------------------
 -- Appending and concatenation