From ad79d55816d8aaad8e51cdab1268686fe598d42f Mon Sep 17 00:00:00 2001
From: Bodigrim <andrew.lelechenko@gmail.com>
Date: Sun, 10 May 2020 16:20:59 +0100
Subject: [PATCH] Add IsList instances

---
 Changelog.md                      |  1 +
 Data/ByteString/Internal.hs       | 12 ++++++++++++
 Data/ByteString/Lazy/Internal.hs  | 14 +++++++++++++-
 Data/ByteString/Short/Internal.hs | 12 ++++++++++--
 4 files changed, 36 insertions(+), 3 deletions(-)

diff --git a/Changelog.md b/Changelog.md
index 3a77d0f2d..249de059e 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -1,6 +1,7 @@
 0.10.10.2 –
 
  * Add `takeWhileEnd`, `dropWhileEnd` and `strip`  for strict bytestrings
+ * Add `IsList` instances
 
 0.10.10.1 – June 2020
 
diff --git a/Data/ByteString/Internal.hs b/Data/ByteString/Internal.hs
index 4f8050ba4..c39fb32a3 100644
--- a/Data/ByteString/Internal.hs
+++ b/Data/ByteString/Internal.hs
@@ -1,6 +1,7 @@
 {-# LANGUAGE CPP, ForeignFunctionInterface, BangPatterns #-}
 {-# LANGUAGE UnliftedFFITypes, MagicHash,
             UnboxedTuples, DeriveDataTypeable #-}
+{-# LANGUAGE TypeFamilies #-}
 #if __GLASGOW_HASKELL__ >= 703
 {-# LANGUAGE Unsafe #-}
 #endif
@@ -117,6 +118,10 @@ import Data.Data                (Data(..), mkNoRepType)
 
 import GHC.Base                 (nullAddr#,realWorld#,unsafeChr)
 
+#if MIN_VERSION_base(4,7,0)
+import GHC.Exts                 (IsList(..))
+#endif
+
 #if MIN_VERSION_base(4,4,0)
 import GHC.CString              (unpackCString#)
 #else
@@ -182,6 +187,13 @@ instance Show ByteString where
 instance Read ByteString where
     readsPrec p str = [ (packChars x, y) | (x, y) <- readsPrec p str ]
 
+#if MIN_VERSION_base(4,7,0)
+instance IsList ByteString where
+  type Item ByteString = Word8
+  fromList = packBytes
+  toList   = unpackBytes
+#endif
+
 instance IsString ByteString where
     fromString = packChars
 
diff --git a/Data/ByteString/Lazy/Internal.hs b/Data/ByteString/Lazy/Internal.hs
index bd07fb570..ec6d947eb 100644
--- a/Data/ByteString/Lazy/Internal.hs
+++ b/Data/ByteString/Lazy/Internal.hs
@@ -1,5 +1,6 @@
 {-# LANGUAGE CPP #-}
 {-# LANGUAGE DeriveDataTypeable #-}
+{-# LANGUAGE TypeFamilies #-}
 #if __GLASGOW_HASKELL__ >= 703
 {-# LANGUAGE Unsafe #-}
 #endif
@@ -13,7 +14,7 @@
 -- Maintainer  : dons00@gmail.com, duncan@community.haskell.org
 -- Stability   : unstable
 -- Portability : non-portable
--- 
+--
 -- A module containing semi-public 'ByteString' internals. This exposes
 -- the 'ByteString' representation and low level construction functions.
 -- Modules which extend the 'ByteString' system will need to use this module
@@ -68,6 +69,10 @@ import Data.String      (IsString(..))
 import Data.Typeable            (Typeable)
 import Data.Data                (Data(..), mkNoRepType)
 
+#if MIN_VERSION_base(4,7,0)
+import GHC.Exts                 (IsList(..))
+#endif
+
 -- | A space-efficient representation of a 'Word8' vector, supporting many
 -- efficient operations.
 --
@@ -110,6 +115,13 @@ instance Show ByteString where
 instance Read ByteString where
     readsPrec p str = [ (packChars x, y) | (x, y) <- readsPrec p str ]
 
+#if MIN_VERSION_base(4,7,0)
+instance IsList ByteString where
+  type Item ByteString = Word8
+  fromList = packBytes
+  toList   = unpackBytes
+#endif
+
 instance IsString ByteString where
     fromString = packChars
 
diff --git a/Data/ByteString/Short/Internal.hs b/Data/ByteString/Short/Internal.hs
index 17ff47db0..5da0fbe21 100644
--- a/Data/ByteString/Short/Internal.hs
+++ b/Data/ByteString/Short/Internal.hs
@@ -1,6 +1,7 @@
 {-# LANGUAGE DeriveDataTypeable, CPP, BangPatterns, RankNTypes,
              ForeignFunctionInterface, MagicHash, UnboxedTuples,
              UnliftedFFITypes #-}
+{-# LANGUAGE TypeFamilies #-}
 {-# OPTIONS_GHC -fno-warn-name-shadowing #-}
 #if __GLASGOW_HASKELL__ >= 703
 {-# LANGUAGE Unsafe #-}
@@ -15,7 +16,7 @@
 -- Maintainer  : duncan@community.haskell.org
 -- Stability   : stable
 -- Portability : ghc only
--- 
+--
 -- Internal representation of ShortByteString
 --
 module Data.ByteString.Short.Internal (
@@ -170,6 +171,13 @@ instance Show ShortByteString where
 instance Read ShortByteString where
     readsPrec p str = [ (packChars x, y) | (x, y) <- readsPrec p str ]
 
+#if MIN_VERSION_base(4,7,0)
+instance GHC.Exts.IsList ShortByteString where
+  type Item ShortByteString = Word8
+  fromList = packBytes
+  toList   = unpackBytes
+#endif
+
 instance IsString ShortByteString where
     fromString = packChars
 
@@ -198,7 +206,7 @@ length (SBS _ len) = len
 null :: ShortByteString -> Bool
 null sbs = length sbs == 0
 
--- | /O(1)/ 'ShortByteString' index (subscript) operator, starting from 0. 
+-- | /O(1)/ 'ShortByteString' index (subscript) operator, starting from 0.
 index :: ShortByteString -> Int -> Word8
 index sbs i
   | i >= 0 && i < length sbs = unsafeIndex sbs i