diff --git a/Z-Data.cabal b/Z-Data.cabal
--- a/Z-Data.cabal
+++ b/Z-Data.cabal
@@ -1,6 +1,6 @@
 cabal-version:      2.4
 name:               Z-Data
-version:            1.1.0.0
+version:            1.2.0.0
 synopsis:           Array, vector and text
 description:        This package provides array, slice and text operations
 license:            BSD-3-Clause
diff --git a/Z/Data/Builder/Numeric.hs b/Z/Data/Builder/Numeric.hs
--- a/Z/Data/Builder/Numeric.hs
+++ b/Z/Data/Builder/Numeric.hs
@@ -37,6 +37,7 @@
   , i2wDec, i2wHex, i2wHexUpper
   , countDigits
   , c_intWith, hs_intWith
+  , quotRem10
 ) where
 
 import           Control.Monad
@@ -62,7 +63,8 @@
 
 --------------------------------------------------------------------------------
 
-foreign import ccall unsafe "dtoa.h" c_int_dec :: Word64 -> Int -> Int -> Word8 -> MBA# Word8 -> Int -> IO Int
+foreign import ccall unsafe "dtoa.h"
+    c_int_dec :: Word64 -> Int -> Int -> Word8 -> MBA# Word8 -> Int -> IO Int
 
 -- | Integral formatting options.
 --
@@ -142,8 +144,8 @@
     ensureN (max 21 width) (\ (MutablePrimArray mba#) i ->
         if x < 0
         then let !x' = (fromIntegral (complement x) :: Word64) + 1
-             in (c_int_dec x' (-1) width pad mba# i)
-        else c_int_dec (fromIntegral x) (if posSign then 1 else 0) width pad mba# i)
+             in (c_int_dec x' (-1) width pad (MBA# mba#) i)
+        else c_int_dec (fromIntegral x) (if posSign then 1 else 0) width pad (MBA# mba#) i)
   where
     pad = case padding of NoPadding          -> 0
                           RightSpacePadding  -> 1
@@ -629,7 +631,7 @@
     then ([0], 0)
     else case c of
 #ifdef INTEGER_GMP
-        (S# i#) -> goI (I# i#) 0 []
+        (S# i#) -> goI (W# (int2Word# i#)) 0 []
 #endif
         _ -> go c 0 []
   where
@@ -642,11 +644,23 @@
     go i !n ds = case i `quotRemInteger` 10 of
                      (# q, r #) -> let !d = fromIntegral r in go q (n+1) (d:ds)
 #ifdef INTEGER_GMP
-    goI :: Int -> Int -> [Int] -> ([Int], Int)
+    goI :: Word -> Int -> [Int] -> ([Int], Int)
     goI 0 !n ds = let !ne = n + e in (ds, ne)
-    goI i !n ds = case i `quotRem` 10 of (q, !r) -> goI q (n+1) (r:ds)
+    goI i !n ds = case quotRem10 i of (q, r) -> let !d = fromIntegral r in goI q (n+1) (d:ds)
 #endif
 
+-- | A faster `quotRem` by 10.
+quotRem10 :: Word -> (Word, Word)
+{-# INLINE quotRem10 #-}
+quotRem10 (W# w#) =
+    let w'# = dquot10# w#
+    in (W# w'#, W# (w# `minusWord#` (w'# `timesWord#` 10##)))
+  where
+    dquot10# :: Word# -> Word#
+    dquot10# w =
+        let !(# rdx, _ #) = w `timesWord2#` 0xCCCCCCCCCCCCCCCD##
+        in rdx `uncheckedShiftRL#` 3#
+
 -- | Worker function to do formatting.
 doFmt :: FFormat
       -> Maybe Int -- ^ Number of decimal places to render.
@@ -751,7 +765,7 @@
     (MutableByteArray pBuf) <- newByteArray GRISU3_DOUBLE_BUF_LEN
     (len, (e, success)) <- allocPrimUnsafe $ \ pLen ->
         allocPrimUnsafe $ \ pE ->
-            c_grisu3 (realToFrac d) pBuf pLen pE
+            c_grisu3 (realToFrac d) (MBA# pBuf) pLen pE
     if success == 0 -- grisu3 fail
     then pure (floatToDigits 10 d)
     else do
@@ -775,7 +789,7 @@
     (MutableByteArray pBuf) <- newByteArray GRISU3_SINGLE_BUF_LEN
     (len, (e, success)) <- allocPrimUnsafe $ \ pLen ->
         allocPrimUnsafe $ \ pE ->
-            c_grisu3_sp (realToFrac d) pBuf pLen pE
+            c_grisu3_sp (realToFrac d) (MBA# pBuf) pLen pE
     if success == 0 -- grisu3 fail
     then pure (floatToDigits 10 d)
     else do
diff --git a/Z/Data/Builder/UUID.hs b/Z/Data/Builder/UUID.hs
--- a/Z/Data/Builder/UUID.hs
+++ b/Z/Data/Builder/UUID.hs
@@ -43,7 +43,7 @@
     B.hex w5
     B.hex w6
 
--- | Write texutal UUID bytes, e.g. @550e8400-e29b-41d4-a716-446655440000@
+-- | Write texutal UUID bytes in UPPERCASE, e.g. @550E8400-E29B-41D4-A716-446655440000@
 uuidUpper :: UUID -> B.Builder ()
 {-# INLINABLE uuidUpper #-}
 uuidUpper (UUID wh wl) =  do
@@ -65,7 +65,7 @@
     B.hexUpper w6
 
 
--- | Encode binary UUID(two 64-bits word in big-endian), as described in <http://tools.ietf.org/html/rfc4122 RFC 4122>. 
+-- | Encode binary UUID(two 64-bits word in big-endian), as described in <https://datatracker.ietf.org/doc/html/rfc4122 RFC 4122>. 
 encodeUUID :: UUID -> B.Builder ()
 {-# INLINABLE  encodeUUID #-}
 encodeUUID (UUID wh wl) = do 
diff --git a/Z/Data/CBytes.hs b/Z/Data/CBytes.hs
--- a/Z/Data/CBytes.hs
+++ b/Z/Data/CBytes.hs
@@ -192,10 +192,10 @@
 -- | Poke 'CBytes' until a \\NUL terminator(or to the end of the array if there's none).
 peekMBACBytes :: MBA# Word8 -> Int -> IO CBytes
 {-# INLINE peekMBACBytes #-}
-peekMBACBytes mba# i = do
+peekMBACBytes mba@(MBA# mba#) i = do
     b <- getSizeofMutableByteArray (MutableByteArray mba#)
     let rest = b-i
-    l <- c_memchr mba# i 0 rest
+    l <- c_memchr mba i 0 rest
     let l' = if l == -1 then rest else l
     mpa <- newPrimArray (l'+1)
     copyMutablePrimArray mpa 0 (MutablePrimArray mba#) i l'
@@ -207,14 +207,14 @@
 -- | Poke 'CBytes' with \\NUL terminator.
 pokeMBACBytes :: MBA# Word8 -> Int -> CBytes -> IO ()
 {-# INLINE pokeMBACBytes #-}
-pokeMBACBytes mba# i (CBytes pa) = do
+pokeMBACBytes (MBA# mba#) i (CBytes pa) = do
         let l = sizeofPrimArray pa
         copyPrimArray (MutablePrimArray mba# :: MutablePrimArray RealWorld Word8) i pa 0 l
 
 -- | Index a 'CBytes' until a \\NUL terminator(or to the end of the array if there's none).
 indexBACBytes :: BA# Word8 -> Int -> CBytes
 {-# INLINE indexBACBytes #-}
-indexBACBytes ba# i = runST (do
+indexBACBytes (BA# ba#) i = runST (do
     let b = sizeofByteArray (ByteArray ba#)
         rest = b-i
         l = V.c_memchr ba# i 0 rest
@@ -611,9 +611,9 @@
                                         \ (_, b) -> return (empty, b)
                          | otherwise = do
     mba@(MutablePrimArray mba#) <- newPrimArray n :: IO (MutablePrimArray RealWorld Word8)
-    a <- fill mba#
-    l <- fromIntegral <$> (c_memchr mba# 0 0 n)
-    let l' = if l == -1 then (n-1) else l
+    a <- fill (MBA# mba#)
+    l <- fromIntegral <$> c_memchr (MBA# mba#) 0 0 n
+    let l' = if l == -1 then n-1 else l
     shrinkMutablePrimArray mba (l'+1)
     writePrimArray mba l' 0
     bs <- unsafeFreezePrimArray mba
@@ -634,8 +634,8 @@
                    | otherwise = do
     mba@(MutablePrimArray mba#) <- newPinnedPrimArray n :: IO (MutablePrimArray RealWorld Word8)
     a <- withMutablePrimArrayContents mba (fill . castPtr)
-    l <- fromIntegral <$> (c_memchr mba# 0 0 n)
-    let l' = if l == -1 then (n-1) else l
+    l <- fromIntegral <$> c_memchr (MBA# mba#) 0 0 n
+    let l' = if l == -1 then n-1 else l
     shrinkMutablePrimArray mba (l'+1)
     writePrimArray mba l' 0
     bs <- unsafeFreezePrimArray mba
@@ -658,4 +658,5 @@
 c_strlen_ptr (Ptr a#) = V.c_strlen a#
 
 -- HsInt hs_memchr(uint8_t *a, HsInt aoff, uint8_t b, HsInt n);
-foreign import ccall unsafe "hs_memchr" c_memchr :: MBA# Word8 -> Int -> Word8 -> Int -> IO Int
+foreign import ccall unsafe "hs_memchr"
+    c_memchr :: MBA# Word8 -> Int -> Word8 -> Int -> IO Int
diff --git a/Z/Data/JSON.hs b/Z/Data/JSON.hs
--- a/Z/Data/JSON.hs
+++ b/Z/Data/JSON.hs
@@ -72,6 +72,7 @@
 import           Z.Data.JSON.Base
 import qualified Z.Data.Parser                  as P
 import qualified Z.Data.Text                    as T
+import           Data.UUID.Types                (UUID)
 
 -- $use
 --
@@ -391,6 +392,16 @@
     encodeJSON Saturday  = "\"Saturday\""
     encodeJSON Sunday    = "\"Sunday\""
 
+instance JSON UUID where
+    {-# INLINE fromValue #-}
+    fromValue = withText "UUID" $ \ t ->
+        case P.parse' (P.uuid <* P.endOfInput) (T.getUTF8Bytes t) of
+            Left err -> fail' $ "could not parse UUID: " <> T.toText err
+            Right r  -> return r
+    {-# INLINE toValue #-}
+    toValue = String . B.unsafeBuildText . B.quotes . B.uuid
+    {-# INLINE encodeJSON #-}
+    encodeJSON = B.quotes . B.uuid
 
 --------------------------------------------------------------------------------
 
diff --git a/Z/Data/Parser/UUID.hs b/Z/Data/Parser/UUID.hs
--- a/Z/Data/Parser/UUID.hs
+++ b/Z/Data/Parser/UUID.hs
@@ -39,7 +39,7 @@
 
     pure (UUID w1 w2)
 
--- | Decode binary UUID(two 64-bits word in big-endian), as described in <http://tools.ietf.org/html/rfc4122 RFC 4122>. 
+-- | Decode binary UUID(two 64-bits word in big-endian), as described in <https://datatracker.ietf.org/doc/html/rfc4122 RFC 4122>. 
 decodeUUID :: P.Parser UUID
 {-# INLINABLE  decodeUUID #-}
 decodeUUID = UUID <$> P.decodeWord64BE <*> P.decodeWord64BE
diff --git a/Z/Data/Text/Regex.hs b/Z/Data/Text/Regex.hs
--- a/Z/Data/Text/Regex.hs
+++ b/Z/Data/Text/Regex.hs
@@ -115,7 +115,9 @@
 {-# NOINLINE regex #-}
 regex t = unsafePerformIO $ do
     (cp, r) <- newCPtrUnsafe (\ mba# ->
-        (withPrimVectorUnsafe (T.getUTF8Bytes t) (hs_re2_compile_pattern_default mba#)))
+        withPrimVectorUnsafe
+            (T.getUTF8Bytes t)
+            (hs_re2_compile_pattern_default (MBA# mba#)))
         p_hs_re2_delete_pattern
 
     when (r == nullPtr) (throwIO (InvalidRegexPattern t callStack))
@@ -130,8 +132,8 @@
 {-# NOINLINE regexOpts #-}
 regexOpts RegexOpts{..} t = unsafePerformIO $ do
     (cp, r) <- newCPtrUnsafe ( \ mba# ->
-        (withPrimVectorUnsafe (T.getUTF8Bytes t) $ \ p o l ->
-            hs_re2_compile_pattern mba# p o l
+        withPrimVectorUnsafe (T.getUTF8Bytes t) $ \ p o l ->
+            hs_re2_compile_pattern (MBA# mba#) p o l
                 (fromBool posix_syntax  )
                 (fromBool longest_match )
                 max_mem
@@ -142,7 +144,7 @@
                 (fromBool case_sensitive)
                 (fromBool perl_classes  )
                 (fromBool word_boundary )
-                (fromBool one_line      )))
+                (fromBool one_line      ))
         p_hs_re2_delete_pattern
 
     when (r == nullPtr) (throwIO (InvalidRegexPattern t callStack))
diff --git a/Z/Data/Vector/Base64.hs b/Z/Data/Vector/Base64.hs
--- a/Z/Data/Vector/Base64.hs
+++ b/Z/Data/Vector/Base64.hs
@@ -54,7 +54,7 @@
 base64EncodeBuilder (V.PrimVector arr s l) =
     B.writeN (base64EncodeLength l) (\ (MutablePrimArray mba#) i -> do
         withPrimArrayUnsafe arr $ \ parr _ ->
-            hs_base64_encode mba# i parr s l)
+            hs_base64_encode (MBA# mba#) i parr s l)
 
 -- | Text version of 'base64Encode'.
 base64EncodeText :: V.Bytes -> T.Text
diff --git a/Z/Data/Vector/Hex.hs b/Z/Data/Vector/Hex.hs
--- a/Z/Data/Vector/Hex.hs
+++ b/Z/Data/Vector/Hex.hs
@@ -82,8 +82,8 @@
     B.writeN (l `unsafeShiftL` 1) (\ (MutablePrimArray mba#) i -> do
         withPrimArrayUnsafe arr $ \ parr _ ->
             if upper
-            then hs_hex_encode_upper mba# i parr s l
-            else hs_hex_encode mba# i parr s l)
+            then hs_hex_encode_upper (MBA# mba#) i parr s l
+            else hs_hex_encode (MBA# mba#) i parr s l)
 
 -- | Text version of 'hexEncode'.
 hexEncodeText :: Bool   -- ^ uppercase?
diff --git a/Z/Foreign.hs b/Z/Foreign.hs
--- a/Z/Foreign.hs
+++ b/Z/Foreign.hs
@@ -1,3 +1,6 @@
+#if __GLASGOW_HASKELL__ >= 810
+{-# LANGUAGE UnliftedNewtypes #-}
+#endif
 {-|
 Module      : Z.Foreign
 Description : Use PrimArray \/ PrimVector with FFI
@@ -76,7 +79,11 @@
   , pinPrimArray
   , pinPrimVector
     -- ** Pointer helpers
-  , BA#, MBA#, BAArray#
+#if __GLASGOW_HASKELL__ >= 810
+  , BA# (..), MBA# (..), BAArray# (..)
+#else
+  , BA#, pattern BA#, MBA#, pattern MBA#, BAArray#, pattern BAArray#
+#endif
   , clearMBA
   , clearPtr
   , castPtr
@@ -100,26 +107,28 @@
   , hs_delete_std_string
   ) where
 
-import           Control.Exception          (bracket)
+import           Control.Exception              (bracket)
 import           Control.Monad
 import           Control.Monad.Primitive
+import           Data.ByteString                (ByteString)
+import qualified Data.ByteString                as B
+import           Data.ByteString.Short.Internal (ShortByteString (..),
+                                                 fromShort, toShort)
+import qualified Data.ByteString.Unsafe         as B
+import qualified Data.List                      as List
 import           Data.Primitive
-import           Data.Word
-import qualified Data.List                  as List
-import           Data.Primitive.Ptr
 import           Data.Primitive.ByteArray
 import           Data.Primitive.PrimArray
+import           Data.Primitive.Ptr
+import           Data.Word
 import           Foreign.C.Types
-import           GHC.Ptr
 import           GHC.Exts
-import           Z.Data.Array.Base             (withMutablePrimArrayContents, withPrimArrayContents)
+import           GHC.Ptr
+import           Z.Data.Array.Base              (withMutablePrimArrayContents,
+                                                 withPrimArrayContents)
 import           Z.Data.Array.Unaligned
 import           Z.Data.Array.UnliftedArray
 import           Z.Data.Vector.Base
-import           Data.ByteString            (ByteString)
-import qualified Data.ByteString            as B
-import qualified Data.ByteString.Unsafe     as B
-import           Data.ByteString.Short.Internal (ShortByteString(..), fromShort, toShort)
 
 -- | Type alias for 'ByteArray#'.
 --
@@ -133,7 +142,13 @@
 -- So it's users' responsibility to make sure the array content is not mutated (a const pointer type may help).
 --
 -- USE THIS TYPE WITH UNSAFE FFI CALL ONLY. A 'ByteArray#' COULD BE MOVED BY GC DURING SAFE FFI CALL.
+#if __GLASGOW_HASKELL__ >= 810
+newtype BA# a = BA# ByteArray#
+#else
 type BA# a = ByteArray#
+pattern BA# :: ByteArray# -> BA# a
+pattern BA# ba = ba
+#endif
 
 -- | Type alias for 'MutableByteArray#' 'RealWorld'.
 --
@@ -144,7 +159,13 @@
 -- <https://github.com/ghc/ghc/blob/master/compiler/GHC/StgToCmm/Foreign.hs#L542 Note [Unlifted boxed arguments to foreign calls]>
 --
 -- USE THIS TYPE WITH UNSAFE FFI CALL ONLY. A 'MutableByteArray#' COULD BE MOVED BY GC DURING SAFE FFI CALL.
+#if __GLASGOW_HASKELL__ >= 810
+newtype MBA# a = MBA# (MutableByteArray# RealWorld)
+#else
 type MBA# a = MutableByteArray# RealWorld
+pattern MBA# :: MutableByteArray# RealWorld -> MBA# a
+pattern MBA# mba = mba
+#endif
 
 -- | Type alias for 'ArrayArray#'.
 --
@@ -177,17 +198,21 @@
 -- -- by the type system in this example since ArrayArray is untyped.
 -- foreign import ccall unsafe "sum_first" sumFirst :: BAArray# Int -> Int -> IO CInt
 -- @
---
+#if __GLASGOW_HASKELL__ >= 810
+newtype BAArray# a = BAArray# ArrayArray#
+#else
 type BAArray# a = ArrayArray#
+pattern BAArray# :: ArrayArray# -> BAArray# a
+pattern BAArray# baa = baa
+#endif
 
 -- | Clear 'MBA#' with given length to zero.
 clearMBA :: MBA# a
          -> Int  -- ^ in bytes
          -> IO ()
 {-# INLINE clearMBA #-}
-clearMBA mba# len = do
-    let mba = (MutableByteArray mba#)
-    setByteArray mba 0 len (0 :: Word8)
+clearMBA (MBA# mba#) len =
+    setByteArray (MutableByteArray mba#) 0 len (0 :: Word8)
 
 -- | Pass primitive array to unsafe FFI as pointer.
 --
@@ -199,7 +224,7 @@
 -- USE THIS FUNCTION WITH UNSAFE FFI CALL ONLY.
 withPrimArrayUnsafe :: (Prim a) => PrimArray a -> (BA# a -> Int -> IO b) -> IO b
 {-# INLINE withPrimArrayUnsafe #-}
-withPrimArrayUnsafe pa@(PrimArray ba#) f = f ba# (sizeofPrimArray pa)
+withPrimArrayUnsafe pa@(PrimArray ba#) f = f (BA# ba#) (sizeofPrimArray pa)
 
 -- | Pass primitive array list to unsafe FFI as @StgArrBytes**@.
 --
@@ -217,7 +242,7 @@
     mla <- unsafeNewUnliftedArray l
     foldM_ (\ !i pa -> writeUnliftedArray mla i pa >> return (i+1)) 0 pas
     (UnliftedArray la#) <- unsafeFreezeUnliftedArray mla
-    f la# l
+    f (BAArray# la#) l
 
 -- | Allocate some bytes and pass to FFI as pointer, freeze result into a 'PrimArray'.
 --
@@ -226,7 +251,7 @@
 {-# INLINE allocPrimArrayUnsafe #-}
 allocPrimArrayUnsafe len f = do
     (mpa@(MutablePrimArray mba#) :: MutablePrimArray RealWorld a) <- newPrimArray len
-    !r <- f mba#
+    !r <- f (MBA# mba#)
     !pa <- unsafeFreezePrimArray mpa
     return (pa, r)
 
@@ -252,7 +277,7 @@
 {-# INLINE allocPrimVectorUnsafe #-}
 allocPrimVectorUnsafe len f = do
     (mpa@(MutablePrimArray mba#) :: MutablePrimArray RealWorld a) <- newPrimArray len
-    !r <- f mba#
+    !r <- f (MBA# mba#)
     !pa <- unsafeFreezePrimArray mpa
     let !v = PrimVector pa 0 len
     return (v, r)
@@ -261,11 +286,10 @@
 --
 -- USE THIS FUNCTION WITH UNSAFE FFI CALL ONLY.
 allocBytesUnsafe :: Int  -- ^ number of bytes
-                 -> (MBA# a -> IO b) -> IO (Bytes, b)
+                 -> (MBA# Word8 -> IO b) -> IO (Bytes, b)
 {-# INLINE allocBytesUnsafe #-}
 allocBytesUnsafe = allocPrimVectorUnsafe
 
-
 -- | Create an one element primitive array and use it as a pointer to the primitive element.
 --
 -- Return the element and the computation result.
@@ -278,7 +302,7 @@
 withPrimUnsafe v f = do
     mpa@(MutablePrimArray mba#) <- newPrimArray 1    -- All heap objects are WORD aligned
     writePrimArray mpa 0 v
-    !b <- f mba#                                      -- so no need to do extra alignment
+    !b <- f (MBA# mba#)                              -- so no need to do extra alignment
     !a <- readPrimArray mpa 0
     return (a, b)
 
@@ -289,7 +313,7 @@
 {-# INLINE allocPrimUnsafe #-}
 allocPrimUnsafe f = do
     mpa@(MutablePrimArray mba#) <- newPrimArray 1    -- All heap objects are WORD aligned
-    !b <- f mba#                                      -- so no need to do extra alignment
+    !b <- f (MBA# mba#)                              -- so no need to do extra alignment
     !a <- readPrimArray mpa 0
     return (a, b)
 
diff --git a/Z/Foreign/CPtr.hs b/Z/Foreign/CPtr.hs
--- a/Z/Foreign/CPtr.hs
+++ b/Z/Foreign/CPtr.hs
@@ -139,7 +139,7 @@
     foldM_ (\ !i (CPtr pa) ->
         writePrimArray mpa i (indexPrimArray pa 0) >> return (i+1)) 0 cptrs
     (PrimArray ba#) <- unsafeFreezePrimArray mpa
-    r <- f ba# len
+    r <- f (BA# ba#) len
     primitive_ (touch# cptrs)
     return r
   where len = length cptrs