+++ /dev/null
-{-# OPTIONS_GHC -cpp -fglasgow-exts -fno-warn-orphans #-}
--- |
--- Module : Data.ByteString
--- Copyright : (c) The University of Glasgow 2001,
--- (c) David Roundy 2003-2005,
--- (c) Simon Marlow 2005
--- (c) Don Stewart 2005-2006
--- (c) Bjorn Bringert 2006
--- Array fusion code:
--- (c) 2001,2002 Manuel M T Chakravarty & Gabriele Keller
--- (c) 2006 Manuel M T Chakravarty & Roman Leshchinskiy
---
--- License : BSD-style
---
--- Maintainer : dons@cse.unsw.edu.au
--- Stability : experimental
--- Portability : portable
---
--- A time and space-efficient implementation of byte vectors using
--- packed Word8 arrays, suitable for high performance use, both in terms
--- of large data quantities, or high speed requirements. Byte vectors
--- are encoded as strict 'Word8' arrays of bytes, held in a 'ForeignPtr',
--- and can be passed between C and Haskell with little effort.
---
--- This module is intended to be imported @qualified@, to avoid name
--- clashes with "Prelude" functions. eg.
---
--- > import qualified Data.ByteString as B
---
--- Original GHC implementation by Bryan O\'Sullivan.
--- Rewritten to use 'Data.Array.Unboxed.UArray' by Simon Marlow.
--- Rewritten to support slices and use 'ForeignPtr' by David Roundy.
--- Polished and extended by Don Stewart.
---
-
-module Data.ByteString (
-
- -- * The @ByteString@ type
- ByteString, -- abstract, instances: Eq, Ord, Show, Read, Data, Typeable, Monoid
-
- -- * Introducing and eliminating 'ByteString's
- empty, -- :: ByteString
- singleton, -- :: Word8 -> ByteString
- pack, -- :: [Word8] -> ByteString
- unpack, -- :: ByteString -> [Word8]
-
- -- * Basic interface
- cons, -- :: Word8 -> ByteString -> ByteString
- snoc, -- :: ByteString -> Word8 -> ByteString
- append, -- :: ByteString -> ByteString -> ByteString
- head, -- :: ByteString -> Word8
- last, -- :: ByteString -> Word8
- tail, -- :: ByteString -> ByteString
- init, -- :: ByteString -> ByteString
- null, -- :: ByteString -> Bool
- length, -- :: ByteString -> Int
-
- -- * Transformating ByteStrings
- map, -- :: (Word8 -> Word8) -> ByteString -> ByteString
- reverse, -- :: ByteString -> ByteString
- intersperse, -- :: Word8 -> ByteString -> ByteString
- transpose, -- :: [ByteString] -> [ByteString]
-
- -- * Reducing 'ByteString's (folds)
- foldl, -- :: (a -> Word8 -> a) -> a -> ByteString -> a
- foldl', -- :: (a -> Word8 -> a) -> a -> ByteString -> a
- foldl1, -- :: (Word8 -> Word8 -> Word8) -> ByteString -> Word8
- foldl1', -- :: (Word8 -> Word8 -> Word8) -> ByteString -> Word8
-
- foldr, -- :: (Word8 -> a -> a) -> a -> ByteString -> a
- foldr', -- :: (Word8 -> a -> a) -> a -> ByteString -> a
- foldr1, -- :: (Word8 -> Word8 -> Word8) -> ByteString -> Word8
- foldr1', -- :: (Word8 -> Word8 -> Word8) -> ByteString -> Word8
-
- -- ** Special folds
- concat, -- :: [ByteString] -> ByteString
- concatMap, -- :: (Word8 -> ByteString) -> ByteString -> ByteString
- any, -- :: (Word8 -> Bool) -> ByteString -> Bool
- all, -- :: (Word8 -> Bool) -> ByteString -> Bool
- maximum, -- :: ByteString -> Word8
- minimum, -- :: ByteString -> Word8
-
- -- * Building ByteStrings
- -- ** Scans
- scanl, -- :: (Word8 -> Word8 -> Word8) -> Word8 -> ByteString -> ByteString
- scanl1, -- :: (Word8 -> Word8 -> Word8) -> ByteString -> ByteString
- scanr, -- :: (Word8 -> Word8 -> Word8) -> Word8 -> ByteString -> ByteString
- scanr1, -- :: (Word8 -> Word8 -> Word8) -> ByteString -> ByteString
-
- -- ** Accumulating maps
- mapAccumL, -- :: (acc -> Word8 -> (acc, Word8)) -> acc -> ByteString -> (acc, ByteString)
- mapAccumR, -- :: (acc -> Word8 -> (acc, Word8)) -> acc -> ByteString -> (acc, ByteString)
- mapIndexed, -- :: (Int -> Word8 -> Word8) -> ByteString -> ByteString
-
- -- ** Unfolding ByteStrings
- replicate, -- :: Int -> Word8 -> ByteString
- unfoldr, -- :: (a -> Maybe (Word8, a)) -> a -> ByteString
- unfoldrN, -- :: Int -> (a -> Maybe (Word8, a)) -> a -> (ByteString, Maybe a)
-
- -- * Substrings
-
- -- ** Breaking strings
- take, -- :: Int -> ByteString -> ByteString
- drop, -- :: Int -> ByteString -> ByteString
- splitAt, -- :: Int -> ByteString -> (ByteString, ByteString)
- takeWhile, -- :: (Word8 -> Bool) -> ByteString -> ByteString
- dropWhile, -- :: (Word8 -> Bool) -> ByteString -> ByteString
- span, -- :: (Word8 -> Bool) -> ByteString -> (ByteString, ByteString)
- spanEnd, -- :: (Word8 -> Bool) -> ByteString -> (ByteString, ByteString)
- break, -- :: (Word8 -> Bool) -> ByteString -> (ByteString, ByteString)
- breakEnd, -- :: (Word8 -> Bool) -> ByteString -> (ByteString, ByteString)
- group, -- :: ByteString -> [ByteString]
- groupBy, -- :: (Word8 -> Word8 -> Bool) -> ByteString -> [ByteString]
- inits, -- :: ByteString -> [ByteString]
- tails, -- :: ByteString -> [ByteString]
-
- -- ** Breaking into many substrings
- split, -- :: Word8 -> ByteString -> [ByteString]
- splitWith, -- :: (Word8 -> Bool) -> ByteString -> [ByteString]
-
- -- ** Joining strings
- join, -- :: ByteString -> [ByteString] -> ByteString
-
- -- * Predicates
- isPrefixOf, -- :: ByteString -> ByteString -> Bool
- isSuffixOf, -- :: ByteString -> ByteString -> Bool
-
- -- ** Search for arbitrary substrings
- isSubstringOf, -- :: ByteString -> ByteString -> Bool
- findSubstring, -- :: ByteString -> ByteString -> Maybe Int
- findSubstrings, -- :: ByteString -> ByteString -> [Int]
-
- -- * Searching ByteStrings
-
- -- ** Searching by equality
- -- | These functions use memchr(3) to efficiently search the ByteString
- elem, -- :: Word8 -> ByteString -> Bool
- notElem, -- :: Word8 -> ByteString -> Bool
-
- -- ** Searching with a predicate
- find, -- :: (Word8 -> Bool) -> ByteString -> Maybe Word8
- filter, -- :: (Word8 -> Bool) -> ByteString -> ByteString
--- partition -- :: (Word8 -> Bool) -> ByteString -> (ByteString, ByteString)
-
- -- * Indexing ByteStrings
- index, -- :: ByteString -> Int -> Word8
- elemIndex, -- :: Word8 -> ByteString -> Maybe Int
- elemIndices, -- :: Word8 -> ByteString -> [Int]
- elemIndexEnd, -- :: Word8 -> ByteString -> Maybe Int
- findIndex, -- :: (Word8 -> Bool) -> ByteString -> Maybe Int
- findIndices, -- :: (Word8 -> Bool) -> ByteString -> [Int]
- count, -- :: Word8 -> ByteString -> Int
-
- -- * Zipping and unzipping ByteStrings
- zip, -- :: ByteString -> ByteString -> [(Word8,Word8)]
- zipWith, -- :: (Word8 -> Word8 -> c) -> ByteString -> ByteString -> [c]
- unzip, -- :: [(Word8,Word8)] -> (ByteString,ByteString)
-
- -- * Ordered ByteStrings
- sort, -- :: ByteString -> ByteString
-
- -- * Low level CString conversions
-
- -- ** Packing CStrings and pointers
- packCString, -- :: CString -> ByteString
- packCStringLen, -- :: CString -> ByteString
- packMallocCString, -- :: CString -> ByteString
-
- -- ** Using ByteStrings as CStrings
- useAsCString, -- :: ByteString -> (CString -> IO a) -> IO a
- useAsCStringLen, -- :: ByteString -> (CStringLen -> IO a) -> IO a
-
- -- ** Copying ByteStrings
- -- | These functions perform memcpy(3) operations
- copy, -- :: ByteString -> ByteString
- copyCString, -- :: CString -> IO ByteString
- copyCStringLen, -- :: CStringLen -> IO ByteString
-
- -- * I\/O with 'ByteString's
-
- -- ** Standard input and output
- getLine, -- :: IO ByteString
- getContents, -- :: IO ByteString
- putStr, -- :: ByteString -> IO ()
- putStrLn, -- :: ByteString -> IO ()
- interact, -- :: (ByteString -> ByteString) -> IO ()
-
- -- ** Files
- readFile, -- :: FilePath -> IO ByteString
- writeFile, -- :: FilePath -> ByteString -> IO ()
- appendFile, -- :: FilePath -> ByteString -> IO ()
--- mmapFile, -- :: FilePath -> IO ByteString
-
- -- ** I\/O with Handles
- hGetLine, -- :: Handle -> IO ByteString
- hGetContents, -- :: Handle -> IO ByteString
- hGet, -- :: Handle -> Int -> IO ByteString
- hGetNonBlocking, -- :: Handle -> Int -> IO ByteString
- hPut, -- :: Handle -> ByteString -> IO ()
- hPutStr, -- :: Handle -> ByteString -> IO ()
- hPutStrLn, -- :: Handle -> ByteString -> IO ()
-
-#if defined(__GLASGOW_HASKELL__)
- -- * Fusion utilities
- unpackList, -- eek, otherwise it gets thrown away by the simplifier
- lengthU, maximumU, minimumU
-#endif
-
- ) where
-
-import qualified Prelude as P
-import Prelude hiding (reverse,head,tail,last,init,null
- ,length,map,lines,foldl,foldr,unlines
- ,concat,any,take,drop,splitAt,takeWhile
- ,dropWhile,span,break,elem,filter,maximum
- ,minimum,all,concatMap,foldl1,foldr1
- ,scanl,scanl1,scanr,scanr1
- ,readFile,writeFile,appendFile,replicate
- ,getContents,getLine,putStr,putStrLn,interact
- ,zip,zipWith,unzip,notElem)
-
-import Data.ByteString.Base
-import Data.ByteString.Fusion
-
-import qualified Data.List as List
-
-import Data.Word (Word8)
-import Data.Maybe (listToMaybe)
-import Data.Array (listArray)
-import qualified Data.Array as Array ((!))
-
--- Control.Exception.bracket not available in yhc or nhc
-import Control.Exception (bracket, assert)
-import qualified Control.Exception as Exception
-import Control.Monad (when)
-
-import Foreign.C.String (CString, CStringLen)
-import Foreign.C.Types (CSize)
-import Foreign.ForeignPtr
-import Foreign.Marshal.Array
-import Foreign.Ptr
-import Foreign.Storable (Storable(..))
-
--- hGetBuf and hPutBuf not available in yhc or nhc
-import System.IO (stdin,stdout,hClose,hFileSize
- ,hGetBuf,hPutBuf,openBinaryFile
- ,Handle,IOMode(..))
-
-import Data.Monoid (Monoid, mempty, mappend, mconcat)
-
-#if !defined(__GLASGOW_HASKELL__)
-import System.IO.Unsafe
-import qualified System.Environment
-import qualified System.IO (hGetLine)
-#endif
-
-#if defined(__GLASGOW_HASKELL__)
-
-import System.IO (hGetBufNonBlocking)
-import System.IO.Error (isEOFError)
-
-import GHC.Handle
-import GHC.Prim (Word#, (+#), writeWord8OffAddr#)
-import GHC.Base (build)
-import GHC.Word hiding (Word8)
-import GHC.Ptr (Ptr(..))
-import GHC.ST (ST(..))
-import GHC.IOBase
-
-#endif
-
--- -----------------------------------------------------------------------------
---
--- Useful macros, until we have bang patterns
---
-
-#define STRICT1(f) f a | a `seq` False = undefined
-#define STRICT2(f) f a b | a `seq` b `seq` False = undefined
-#define STRICT3(f) f a b c | a `seq` b `seq` c `seq` False = undefined
-#define STRICT4(f) f a b c d | a `seq` b `seq` c `seq` d `seq` False = undefined
-#define STRICT5(f) f a b c d e | a `seq` b `seq` c `seq` d `seq` e `seq` False = undefined
-
--- -----------------------------------------------------------------------------
-
-instance Eq ByteString
- where (==) = eq
-
-instance Ord ByteString
- where compare = compareBytes
-
-instance Monoid ByteString where
- mempty = empty
- mappend = append
- mconcat = concat
-
-{-
-instance Arbitrary PackedString where
- arbitrary = P.pack `fmap` arbitrary
- coarbitrary s = coarbitrary (P.unpack s)
--}
-
--- | /O(n)/ Equality on the 'ByteString' type.
-eq :: ByteString -> ByteString -> Bool
-eq a@(PS p s l) b@(PS p' s' l')
- | l /= l' = False -- short cut on length
- | p == p' && s == s' = True -- short cut for the same string
- | otherwise = compareBytes a b == EQ
-{-# INLINE eq #-}
-
--- | /O(n)/ 'compareBytes' provides an 'Ordering' for 'ByteStrings' supporting slices.
-compareBytes :: ByteString -> ByteString -> Ordering
-compareBytes (PS x1 s1 l1) (PS x2 s2 l2)
- | l1 == 0 && l2 == 0 = EQ -- short cut for empty strings
- | x1 == x2 && s1 == s2 && l1 == l2 = EQ -- short cut for the same string
- | otherwise = inlinePerformIO $
- withForeignPtr x1 $ \p1 ->
- withForeignPtr x2 $ \p2 -> do
- i <- memcmp (p1 `plusPtr` s1) (p2 `plusPtr` s2) (fromIntegral $ min l1 l2)
- return $! case i `compare` 0 of
- EQ -> l1 `compare` l2
- x -> x
-{-# INLINE compareBytes #-}
-
-{-
---
--- About 4x slower over 32M
---
-compareBytes :: ByteString -> ByteString -> Ordering
-compareBytes (PS fp1 off1 len1) (PS fp2 off2 len2) = inlinePerformIO $
- withForeignPtr fp1 $ \p1 ->
- withForeignPtr fp2 $ \p2 ->
- cmp (p1 `plusPtr` off1)
- (p2 `plusPtr` off2) 0 len1 len2
-
-cmp :: Ptr Word8 -> Ptr Word8 -> Int -> Int -> Int-> IO Ordering
-STRICT5(cmp)
-cmp p1 p2 n len1 len2
- | n == len1 = if n == len2 then return EQ else return LT
- | n == len2 = return GT
- | otherwise = do
- (a :: Word8) <- peekByteOff p1 n
- (b :: Word8) <- peekByteOff p2 n
- case a `compare` b of
- EQ -> cmp p1 p2 (n+1) len1 len2
- LT -> return LT
- GT -> return GT
-{-# INLINE compareBytes #-}
--}
-
--- -----------------------------------------------------------------------------
--- Introducing and eliminating 'ByteString's
-
--- | /O(1)/ Convert a 'Word8' into a 'ByteString'
-singleton :: Word8 -> ByteString
-singleton c = unsafeCreate 1 $ \p -> poke p c
-{-# INLINE [1] singleton #-}
-
---
--- XXX The unsafePerformIO is critical!
---
--- Otherwise:
---
--- singleton 255 `compare` singleton 127
---
--- is compiled to:
---
--- case mallocByteString 2 of
--- ForeignPtr f internals ->
--- case writeWord8OffAddr# f 0 255 of _ ->
--- case writeWord8OffAddr# f 0 127 of _ ->
--- case eqAddr# f f of
--- False -> case compare (GHC.Prim.plusAddr# f 0)
--- (GHC.Prim.plusAddr# f 0)
---
---
-
--- | /O(n)/ Convert a '[Word8]' into a 'ByteString'.
---
--- For applications with large numbers of string literals, pack can be a
--- bottleneck. In such cases, consider using packAddress (GHC only).
-pack :: [Word8] -> ByteString
-
-#if !defined(__GLASGOW_HASKELL__)
-
-pack str = unsafeCreate (P.length str) $ \p -> go p str
- where
- go _ [] = return ()
- go p (x:xs) = poke p x >> go (p `plusPtr` 1) xs -- less space than pokeElemOff
-
-#else /* hack away */
-
-pack str = unsafeCreate (P.length str) $ \(Ptr p) -> stToIO (go p 0# str)
- where
- go _ _ [] = return ()
- go p i (W8# c:cs) = writeByte p i c >> go p (i +# 1#) cs
-
- writeByte p i c = ST $ \s# ->
- case writeWord8OffAddr# p i c s# of s2# -> (# s2#, () #)
-
-#endif
-
--- | /O(n)/ Converts a 'ByteString' to a '[Word8]'.
-unpack :: ByteString -> [Word8]
-
-#if !defined(__GLASGOW_HASKELL__)
-
-unpack (PS _ _ 0) = []
-unpack (PS ps s l) = inlinePerformIO $ withForeignPtr ps $ \p ->
- go (p `plusPtr` s) (l - 1) []
- where
- STRICT3(go)
- go p 0 acc = peek p >>= \e -> return (e : acc)
- go p n acc = peekByteOff p n >>= \e -> go p (n-1) (e : acc)
-{-# INLINE unpack #-}
-
-#else
-
-unpack ps = build (unpackFoldr ps)
-{-# INLINE unpack #-}
-
---
--- critical this isn't strict in the acc
--- as it will break in the presence of list fusion. this is a known
--- issue with seq and build/foldr rewrite rules, which rely on lazy
--- demanding to avoid bottoms in the list.
---
-unpackFoldr :: ByteString -> (Word8 -> a -> a) -> a -> a
-unpackFoldr (PS fp off len) f ch = withPtr fp $ \p -> do
- let loop q n _ | q `seq` n `seq` False = undefined -- n.b.
- loop _ (-1) acc = return acc
- loop q n acc = do
- a <- peekByteOff q n
- loop q (n-1) (a `f` acc)
- loop (p `plusPtr` off) (len-1) ch
-{-# INLINE [0] unpackFoldr #-}
-
-unpackList :: ByteString -> [Word8]
-unpackList (PS fp off len) = withPtr fp $ \p -> do
- let STRICT3(loop)
- loop _ (-1) acc = return acc
- loop q n acc = do
- a <- peekByteOff q n
- loop q (n-1) (a : acc)
- loop (p `plusPtr` off) (len-1) []
-
-{-# RULES
- "FPS unpack-list" [1] forall p . unpackFoldr p (:) [] = unpackList p
- #-}
-
-#endif
-
--- ---------------------------------------------------------------------
--- Basic interface
-
--- | /O(1)/ Test whether a ByteString is empty.
-null :: ByteString -> Bool
-null (PS _ _ l) = assert (l >= 0) $ l <= 0
-{-# INLINE null #-}
-
--- ---------------------------------------------------------------------
--- | /O(1)/ 'length' returns the length of a ByteString as an 'Int'.
-length :: ByteString -> Int
-length (PS _ _ l) = assert (l >= 0) $ l
-
---
--- length/loop fusion. When taking the length of any fuseable loop,
--- rewrite it as a foldl', and thus avoid allocating the result buffer
--- worth around 10% in speed testing.
---
-
-#if defined(__GLASGOW_HASKELL__)
-{-# INLINE [1] length #-}
-#endif
-
-lengthU :: ByteString -> Int
-lengthU = foldl' (const . (+1)) (0::Int)
-{-# INLINE lengthU #-}
-
-{-# RULES
-
--- v2 fusion
-"FPS length/loop" forall loop s .
- length (loopArr (loopWrapper loop s)) =
- lengthU (loopArr (loopWrapper loop s))
-
- #-}
-
-------------------------------------------------------------------------
-
--- | /O(n)/ 'cons' is analogous to (:) for lists, but of different
--- complexity, as it requires a memcpy.
-cons :: Word8 -> ByteString -> ByteString
-cons c (PS x s l) = unsafeCreate (l+1) $ \p -> withForeignPtr x $ \f -> do
- poke p c
- memcpy (p `plusPtr` 1) (f `plusPtr` s) (fromIntegral l)
-{-# INLINE cons #-}
-
--- | /O(n)/ Append a byte to the end of a 'ByteString'
-snoc :: ByteString -> Word8 -> ByteString
-snoc (PS x s l) c = unsafeCreate (l+1) $ \p -> withForeignPtr x $ \f -> do
- memcpy p (f `plusPtr` s) (fromIntegral l)
- poke (p `plusPtr` l) c
-{-# INLINE snoc #-}
-
--- todo fuse
-
--- | /O(1)/ Extract the first element of a ByteString, which must be non-empty.
--- An exception will be thrown in the case of an empty ByteString.
-head :: ByteString -> Word8
-head (PS x s l)
- | l <= 0 = errorEmptyList "head"
- | otherwise = inlinePerformIO $ withForeignPtr x $ \p -> peekByteOff p s
-{-# INLINE head #-}
-
--- | /O(1)/ Extract the elements after the head of a ByteString, which must be non-empty.
--- An exception will be thrown in the case of an empty ByteString.
-tail :: ByteString -> ByteString
-tail (PS p s l)
- | l <= 0 = errorEmptyList "tail"
- | otherwise = PS p (s+1) (l-1)
-{-# INLINE tail #-}
-
--- | /O(1)/ Extract the last element of a ByteString, which must be finite and non-empty.
--- An exception will be thrown in the case of an empty ByteString.
-last :: ByteString -> Word8
-last ps@(PS x s l)
- | null ps = errorEmptyList "last"
- | otherwise = inlinePerformIO $ withForeignPtr x $ \p -> peekByteOff p (s+l-1)
-{-# INLINE last #-}
-
--- | /O(1)/ Return all the elements of a 'ByteString' except the last one.
--- An exception will be thrown in the case of an empty ByteString.
-init :: ByteString -> ByteString
-init ps@(PS p s l)
- | null ps = errorEmptyList "init"
- | otherwise = PS p s (l-1)
-{-# INLINE init #-}
-
--- | /O(n)/ Append two ByteStrings
-append :: ByteString -> ByteString -> ByteString
-append xs ys | null xs = ys
- | null ys = xs
- | otherwise = concat [xs,ys]
-{-# INLINE append #-}
-
--- ---------------------------------------------------------------------
--- Transformations
-
--- | /O(n)/ 'map' @f xs@ is the ByteString obtained by applying @f@ to each
--- element of @xs@. This function is subject to array fusion.
-map :: (Word8 -> Word8) -> ByteString -> ByteString
-#if defined(LOOPU_FUSION)
-map f = loopArr . loopU (mapEFL f) NoAcc
-#elif defined(LOOPUP_FUSION)
-map f = loopArr . loopUp (mapEFL f) NoAcc
-#elif defined(LOOPNOACC_FUSION)
-map f = loopArr . loopNoAcc (mapEFL f)
-#else
-map f = loopArr . loopMap f
-#endif
-{-# INLINE map #-}
-
-{-
--- | /O(n)/ Like 'map', but not fuseable. The benefit is that it is
--- slightly faster for one-shot cases.
-map' :: (Word8 -> Word8) -> ByteString -> ByteString
-map' f (PS fp s len) = inlinePerformIO $ withForeignPtr fp $ \a ->
- create len $ map_ 0 (a `plusPtr` s)
- where
- map_ :: Int -> Ptr Word8 -> Ptr Word8 -> IO ()
- STRICT3(map_)
- map_ n p1 p2
- | n >= len = return ()
- | otherwise = do
- x <- peekByteOff p1 n
- pokeByteOff p2 n (f x)
- map_ (n+1) p1 p2
-{-# INLINE map' #-}
--}
-
--- | /O(n)/ 'reverse' @xs@ efficiently returns the elements of @xs@ in reverse order.
-reverse :: ByteString -> ByteString
-reverse (PS x s l) = unsafeCreate l $ \p -> withForeignPtr x $ \f ->
- c_reverse p (f `plusPtr` s) (fromIntegral l)
-
--- todo, fuseable version
-
--- | /O(n)/ The 'intersperse' function takes a 'Word8' and a
--- 'ByteString' and \`intersperses\' that byte between the elements of
--- the 'ByteString'. It is analogous to the intersperse function on
--- Lists.
-intersperse :: Word8 -> ByteString -> ByteString
-intersperse c ps@(PS x s l)
- | length ps < 2 = ps
- | otherwise = unsafeCreate (2*l-1) $ \p -> withForeignPtr x $ \f ->
- c_intersperse p (f `plusPtr` s) (fromIntegral l) c
-
-{-
-intersperse c = pack . List.intersperse c . unpack
--}
-
--- | The 'transpose' function transposes the rows and columns of its
--- 'ByteString' argument.
-transpose :: [ByteString] -> [ByteString]
-transpose ps = P.map pack (List.transpose (P.map unpack ps))
-
--- ---------------------------------------------------------------------
--- Reducing 'ByteString's
-
--- | 'foldl', applied to a binary operator, a starting value (typically
--- the left-identity of the operator), and a ByteString, reduces the
--- ByteString using the binary operator, from left to right.
--- This function is subject to array fusion.
-foldl :: (a -> Word8 -> a) -> a -> ByteString -> a
-#if !defined(LOOPU_FUSION)
-foldl f z = loopAcc . loopUp (foldEFL f) z
-#else
-foldl f z = loopAcc . loopU (foldEFL f) z
-#endif
-{-# INLINE foldl #-}
-
-{-
---
--- About twice as fast with 6.4.1, but not fuseable
--- A simple fold . map is enough to make it worth while.
---
-foldl f v (PS x s l) = inlinePerformIO $ withForeignPtr x $ \ptr ->
- lgo v (ptr `plusPtr` s) (ptr `plusPtr` (s+l))
- where
- STRICT3(lgo)
- lgo z p q | p == q = return z
- | otherwise = do c <- peek p
- lgo (f z c) (p `plusPtr` 1) q
--}
-
--- | 'foldl\'' is like 'foldl', but strict in the accumulator.
--- Though actually foldl is also strict in the accumulator.
-foldl' :: (a -> Word8 -> a) -> a -> ByteString -> a
-foldl' = foldl
--- foldl' f z = loopAcc . loopU (foldEFL' f) z
-{-# INLINE foldl' #-}
-
--- | 'foldr', applied to a binary operator, a starting value
--- (typically the right-identity of the operator), and a ByteString,
--- reduces the ByteString using the binary operator, from right to left.
-foldr :: (Word8 -> a -> a) -> a -> ByteString -> a
-foldr k z = loopAcc . loopDown (foldEFL (flip k)) z
-{-# INLINE foldr #-}
-
--- | 'foldr\'' is like 'foldr', but strict in the accumulator.
-foldr' :: (Word8 -> a -> a) -> a -> ByteString -> a
-foldr' k v (PS x s l) = inlinePerformIO $ withForeignPtr x $ \ptr ->
- go v (ptr `plusPtr` (s+l-1)) (ptr `plusPtr` (s-1))
- where
- STRICT3(go)
- go z p q | p == q = return z
- | otherwise = do c <- peek p
- go (c `k` z) (p `plusPtr` (-1)) q -- tail recursive
-{-# INLINE [1] foldr' #-}
-
--- | 'foldl1' is a variant of 'foldl' that has no starting value
--- argument, and thus must be applied to non-empty 'ByteStrings'.
--- This function is subject to array fusion.
--- An exception will be thrown in the case of an empty ByteString.
-foldl1 :: (Word8 -> Word8 -> Word8) -> ByteString -> Word8
-foldl1 f ps
- | null ps = errorEmptyList "foldl1"
- | otherwise = foldl f (unsafeHead ps) (unsafeTail ps)
-{-# INLINE foldl1 #-}
-
--- | 'foldl1\'' is like 'foldl1', but strict in the accumulator.
--- An exception will be thrown in the case of an empty ByteString.
-foldl1' :: (Word8 -> Word8 -> Word8) -> ByteString -> Word8
-foldl1' f ps
- | null ps = errorEmptyList "foldl1'"
- | otherwise = foldl' f (unsafeHead ps) (unsafeTail ps)
-{-# INLINE foldl1' #-}
-
--- | 'foldr1' is a variant of 'foldr' that has no starting value argument,
--- and thus must be applied to non-empty 'ByteString's
--- An exception will be thrown in the case of an empty ByteString.
-foldr1 :: (Word8 -> Word8 -> Word8) -> ByteString -> Word8
-foldr1 f ps
- | null ps = errorEmptyList "foldr1"
- | otherwise = foldr f (last ps) (init ps)
-{-# INLINE foldr1 #-}
-
--- | 'foldr1\'' is a variant of 'foldr1', but is strict in the
--- accumulator.
-foldr1' :: (Word8 -> Word8 -> Word8) -> ByteString -> Word8
-foldr1' f ps
- | null ps = errorEmptyList "foldr1"
- | otherwise = foldr' f (last ps) (init ps)
-{-# INLINE [1] foldr1' #-}
-
--- ---------------------------------------------------------------------
--- Special folds
-
--- | /O(n)/ Concatenate a list of ByteStrings.
-concat :: [ByteString] -> ByteString
-concat [] = empty
-concat [ps] = ps
-concat xs = unsafeCreate len $ \ptr -> go xs ptr
- where len = P.sum . P.map length $ xs
- STRICT2(go)
- go [] _ = return ()
- go (PS p s l:ps) ptr = do
- withForeignPtr p $ \fp -> memcpy ptr (fp `plusPtr` s) (fromIntegral l)
- go ps (ptr `plusPtr` l)
-
--- | Map a function over a 'ByteString' and concatenate the results
-concatMap :: (Word8 -> ByteString) -> ByteString -> ByteString
-concatMap f = concat . foldr ((:) . f) []
-
--- foldr (append . f) empty
-
--- | /O(n)/ Applied to a predicate and a ByteString, 'any' determines if
--- any element of the 'ByteString' satisfies the predicate.
-any :: (Word8 -> Bool) -> ByteString -> Bool
-any _ (PS _ _ 0) = False
-any f (PS x s l) = inlinePerformIO $ withForeignPtr x $ \ptr ->
- go (ptr `plusPtr` s) (ptr `plusPtr` (s+l))
- where
- STRICT2(go)
- go p q | p == q = return False
- | otherwise = do c <- peek p
- if f c then return True
- else go (p `plusPtr` 1) q
-
--- todo fuse
-
--- | /O(n)/ Applied to a predicate and a 'ByteString', 'all' determines
--- if all elements of the 'ByteString' satisfy the predicate.
-all :: (Word8 -> Bool) -> ByteString -> Bool
-all _ (PS _ _ 0) = True
-all f (PS x s l) = inlinePerformIO $ withForeignPtr x $ \ptr ->
- go (ptr `plusPtr` s) (ptr `plusPtr` (s+l))
- where
- STRICT2(go)
- go p q | p == q = return True -- end of list
- | otherwise = do c <- peek p
- if f c
- then go (p `plusPtr` 1) q
- else return False
-
-------------------------------------------------------------------------
-
--- | /O(n)/ 'maximum' returns the maximum value from a 'ByteString'
--- This function will fuse.
--- An exception will be thrown in the case of an empty ByteString.
-maximum :: ByteString -> Word8
-maximum xs@(PS x s l)
- | null xs = errorEmptyList "maximum"
- | otherwise = inlinePerformIO $ withForeignPtr x $ \p ->
- c_maximum (p `plusPtr` s) (fromIntegral l)
-
--- | /O(n)/ 'minimum' returns the minimum value from a 'ByteString'
--- This function will fuse.
--- An exception will be thrown in the case of an empty ByteString.
-minimum :: ByteString -> Word8
-minimum xs@(PS x s l)
- | null xs = errorEmptyList "minimum"
- | otherwise = inlinePerformIO $ withForeignPtr x $ \p ->
- c_minimum (p `plusPtr` s) (fromIntegral l)
-
---
--- minimum/maximum/loop fusion. As for length (and other folds), when we
--- see we're applied after a fuseable op, switch from using the C
--- version, to the fuseable version. The result should then avoid
--- allocating a buffer.
---
-
-#if defined(__GLASGOW_HASKELL__)
-{-# INLINE [1] minimum #-}
-{-# INLINE [1] maximum #-}
-#endif
-
-maximumU :: ByteString -> Word8
-maximumU = foldl1' max
-{-# INLINE maximumU #-}
-
-minimumU :: ByteString -> Word8
-minimumU = foldl1' min
-{-# INLINE minimumU #-}
-
-{-# RULES
-
-"FPS minimum/loop" forall loop s .
- minimum (loopArr (loopWrapper loop s)) =
- minimumU (loopArr (loopWrapper loop s))
-
-"FPS maximum/loop" forall loop s .
- maximum (loopArr (loopWrapper loop s)) =
- maximumU (loopArr (loopWrapper loop s))
-
- #-}
-
-------------------------------------------------------------------------
-
--- | The 'mapAccumL' function behaves like a combination of 'map' and
--- 'foldl'; it applies a function to each element of a ByteString,
--- passing an accumulating parameter from left to right, and returning a
--- final value of this accumulator together with the new list.
-mapAccumL :: (acc -> Word8 -> (acc, Word8)) -> acc -> ByteString -> (acc, ByteString)
-#if !defined(LOOPU_FUSION)
-mapAccumL f z = unSP . loopUp (mapAccumEFL f) z
-#else
-mapAccumL f z = unSP . loopU (mapAccumEFL f) z
-#endif
-{-# INLINE mapAccumL #-}
-
--- | The 'mapAccumR' function behaves like a combination of 'map' and
--- 'foldr'; it applies a function to each element of a ByteString,
--- passing an accumulating parameter from right to left, and returning a
--- final value of this accumulator together with the new ByteString.
-mapAccumR :: (acc -> Word8 -> (acc, Word8)) -> acc -> ByteString -> (acc, ByteString)
-mapAccumR f z = unSP . loopDown (mapAccumEFL f) z
-{-# INLINE mapAccumR #-}
-
--- | /O(n)/ map Word8 functions, provided with the index at each position
-mapIndexed :: (Int -> Word8 -> Word8) -> ByteString -> ByteString
-mapIndexed f = loopArr . loopUp (mapIndexEFL f) 0
-{-# INLINE mapIndexed #-}
-
--- ---------------------------------------------------------------------
--- Building ByteStrings
-
--- | 'scanl' is similar to 'foldl', but returns a list of successive
--- reduced values from the left. This function will fuse.
---
--- > scanl f z [x1, x2, ...] == [z, z `f` x1, (z `f` x1) `f` x2, ...]
---
--- Note that
---
--- > last (scanl f z xs) == foldl f z xs.
-scanl :: (Word8 -> Word8 -> Word8) -> Word8 -> ByteString -> ByteString
-#if !defined(LOOPU_FUSION)
-scanl f z ps = loopArr . loopUp (scanEFL f) z $ (ps `snoc` 0)
-#else
-scanl f z ps = loopArr . loopU (scanEFL f) z $ (ps `snoc` 0)
-#endif
-
- -- n.b. haskell's List scan returns a list one bigger than the
- -- input, so we need to snoc here to get some extra space, however,
- -- it breaks map/up fusion (i.e. scanl . map no longer fuses)
-{-# INLINE scanl #-}
-
--- | 'scanl1' is a variant of 'scanl' that has no starting value argument.
--- This function will fuse.
---
--- > scanl1 f [x1, x2, ...] == [x1, x1 `f` x2, ...]
-scanl1 :: (Word8 -> Word8 -> Word8) -> ByteString -> ByteString
-scanl1 f ps
- | null ps = empty
- | otherwise = scanl f (unsafeHead ps) (unsafeTail ps)
-{-# INLINE scanl1 #-}
-
--- | scanr is the right-to-left dual of scanl.
-scanr :: (Word8 -> Word8 -> Word8) -> Word8 -> ByteString -> ByteString
-scanr f z ps = loopArr . loopDown (scanEFL (flip f)) z $ (0 `cons` ps) -- extra space
-{-# INLINE scanr #-}
-
--- | 'scanr1' is a variant of 'scanr' that has no starting value argument.
-scanr1 :: (Word8 -> Word8 -> Word8) -> ByteString -> ByteString
-scanr1 f ps
- | null ps = empty
- | otherwise = scanr f (last ps) (init ps) -- todo, unsafe versions
-{-# INLINE scanr1 #-}
-
--- ---------------------------------------------------------------------
--- Unfolds and replicates
-
--- | /O(n)/ 'replicate' @n x@ is a ByteString of length @n@ with @x@
--- the value of every element. The following holds:
---
--- > replicate w c = unfoldr w (\u -> Just (u,u)) c
---
--- This implemenation uses @memset(3)@
-replicate :: Int -> Word8 -> ByteString
-replicate w c
- | w <= 0 = empty
- | otherwise = unsafeCreate w $ \ptr ->
- memset ptr c (fromIntegral w) >> return ()
-
--- | /O(n)/, where /n/ is the length of the result. The 'unfoldr'
--- function is analogous to the List \'unfoldr\'. 'unfoldr' builds a
--- ByteString from a seed value. The function takes the element and
--- returns 'Nothing' if it is done producing the ByteString or returns
--- 'Just' @(a,b)@, in which case, @a@ is the next byte in the string,
--- and @b@ is the seed value for further production.
---
--- Examples:
---
--- > unfoldr (\x -> if x <= 5 then Just (x, x + 1) else Nothing) 0
--- > == pack [0, 1, 2, 3, 4, 5]
---
-unfoldr :: (a -> Maybe (Word8, a)) -> a -> ByteString
-unfoldr f = concat . unfoldChunk 32 64
- where unfoldChunk n n' x =
- case unfoldrN n f x of
- (s, Nothing) -> s : []
- (s, Just x') -> s : unfoldChunk n' (n+n') x'
-
--- | /O(n)/ Like 'unfoldr', 'unfoldrN' builds a ByteString from a seed
--- value. However, the length of the result is limited by the first
--- argument to 'unfoldrN'. This function is more efficient than 'unfoldr'
--- when the maximum length of the result is known.
---
--- The following equation relates 'unfoldrN' and 'unfoldr':
---
--- > unfoldrN n f s == take n (unfoldr f s)
---
-unfoldrN :: Int -> (a -> Maybe (Word8, a)) -> a -> (ByteString, Maybe a)
-unfoldrN i f x0
- | i < 0 = (empty, Just x0)
- | otherwise = unsafePerformIO $ createAndTrim' i $ \p -> go p x0 0
- where STRICT3(go)
- go p x n =
- case f x of
- Nothing -> return (0, n, Nothing)
- Just (w,x')
- | n == i -> return (0, n, Just x)
- | otherwise -> do poke p w
- go (p `plusPtr` 1) x' (n+1)
-
--- ---------------------------------------------------------------------
--- Substrings
-
--- | /O(1)/ 'take' @n@, applied to a ByteString @xs@, returns the prefix
--- of @xs@ of length @n@, or @xs@ itself if @n > 'length' xs@.
-take :: Int -> ByteString -> ByteString
-take n ps@(PS x s l)
- | n <= 0 = empty
- | n >= l = ps
- | otherwise = PS x s n
-{-# INLINE take #-}
-
--- | /O(1)/ 'drop' @n xs@ returns the suffix of @xs@ after the first @n@
--- elements, or @[]@ if @n > 'length' xs@.
-drop :: Int -> ByteString -> ByteString
-drop n ps@(PS x s l)
- | n <= 0 = ps
- | n >= l = empty
- | otherwise = PS x (s+n) (l-n)
-{-# INLINE drop #-}
-
--- | /O(1)/ 'splitAt' @n xs@ is equivalent to @('take' n xs, 'drop' n xs)@.
-splitAt :: Int -> ByteString -> (ByteString, ByteString)
-splitAt n ps@(PS x s l)
- | n <= 0 = (empty, ps)
- | n >= l = (ps, empty)
- | otherwise = (PS x s n, PS x (s+n) (l-n))
-{-# INLINE splitAt #-}
-
--- | 'takeWhile', applied to a predicate @p@ and a ByteString @xs@,
--- returns the longest prefix (possibly empty) of @xs@ of elements that
--- satisfy @p@.
-takeWhile :: (Word8 -> Bool) -> ByteString -> ByteString
-takeWhile f ps = unsafeTake (findIndexOrEnd (not . f) ps) ps
-{-# INLINE takeWhile #-}
-
--- | 'dropWhile' @p xs@ returns the suffix remaining after 'takeWhile' @p xs@.
-dropWhile :: (Word8 -> Bool) -> ByteString -> ByteString
-dropWhile f ps = unsafeDrop (findIndexOrEnd (not . f) ps) ps
-{-# INLINE dropWhile #-}
-
--- | 'break' @p@ is equivalent to @'span' ('not' . p)@.
-break :: (Word8 -> Bool) -> ByteString -> (ByteString, ByteString)
-break p ps = case findIndexOrEnd p ps of n -> (unsafeTake n ps, unsafeDrop n ps)
-{-# INLINE [1] break #-}
-
-{-# RULES
-"FPS specialise break (x==)" forall x.
- break ((==) x) = breakByte x
- #-}
-
-#if __GLASGOW_HASKELL__ >= 605
-{-# RULES
-"FPS specialise break (==x)" forall x.
- break (==x) = breakByte x
- #-}
-#endif
-
--- | 'breakByte' breaks its ByteString argument at the first occurence
--- of the specified byte. It is more efficient than 'break' as it is
--- implemented with @memchr(3)@. I.e.
---
--- > break (=='c') "abcd" == breakByte 'c' "abcd"
---
-breakByte :: Word8 -> ByteString -> (ByteString, ByteString)
-breakByte c p = case elemIndex c p of
- Nothing -> (p,empty)
- Just n -> (unsafeTake n p, unsafeDrop n p)
-{-# INLINE breakByte #-}
-
--- | 'breakEnd' behaves like 'break' but from the end of the 'ByteString'
---
--- breakEnd p == spanEnd (not.p)
-breakEnd :: (Word8 -> Bool) -> ByteString -> (ByteString, ByteString)
-breakEnd p ps = splitAt (findFromEndUntil p ps) ps
-
--- | 'span' @p xs@ breaks the ByteString into two segments. It is
--- equivalent to @('takeWhile' p xs, 'dropWhile' p xs)@
-span :: (Word8 -> Bool) -> ByteString -> (ByteString, ByteString)
-span p ps = break (not . p) ps
-{-# INLINE [1] span #-}
-
--- | 'spanByte' breaks its ByteString argument at the first
--- occurence of a byte other than its argument. It is more efficient
--- than 'span (==)'
---
--- > span (=='c') "abcd" == spanByte 'c' "abcd"
---
-spanByte :: Word8 -> ByteString -> (ByteString, ByteString)
-spanByte c ps@(PS x s l) = inlinePerformIO $ withForeignPtr x $ \p ->
- go (p `plusPtr` s) 0
- where
- STRICT2(go)
- go p i | i >= l = return (ps, empty)
- | otherwise = do c' <- peekByteOff p i
- if c /= c'
- then return (unsafeTake i ps, unsafeDrop i ps)
- else go p (i+1)
-{-# INLINE spanByte #-}
-
-{-# RULES
-"FPS specialise span (x==)" forall x.
- span ((==) x) = spanByte x
- #-}
-
-#if __GLASGOW_HASKELL__ >= 605
-{-# RULES
-"FPS specialise span (==x)" forall x.
- span (==x) = spanByte x
- #-}
-#endif
-
--- | 'spanEnd' behaves like 'span' but from the end of the 'ByteString'.
--- We have
---
--- > spanEnd (not.isSpace) "x y z" == ("x y ","z")
---
--- and
---
--- > spanEnd (not . isSpace) ps
--- > ==
--- > let (x,y) = span (not.isSpace) (reverse ps) in (reverse y, reverse x)
---
-spanEnd :: (Word8 -> Bool) -> ByteString -> (ByteString, ByteString)
-spanEnd p ps = splitAt (findFromEndUntil (not.p) ps) ps
-
--- | /O(n)/ Splits a 'ByteString' into components delimited by
--- separators, where the predicate returns True for a separator element.
--- The resulting components do not contain the separators. Two adjacent
--- separators result in an empty component in the output. eg.
---
--- > splitWith (=='a') "aabbaca" == ["","","bb","c",""]
--- > splitWith (=='a') [] == []
---
-splitWith :: (Word8 -> Bool) -> ByteString -> [ByteString]
-
-#if defined(__GLASGOW_HASKELL__)
-splitWith _pred (PS _ _ 0) = []
-splitWith pred_ (PS fp off len) = splitWith0 pred# off len fp
- where pred# c# = pred_ (W8# c#)
-
- STRICT4(splitWith0)
- splitWith0 pred' off' len' fp' = withPtr fp $ \p ->
- splitLoop pred' p 0 off' len' fp'
-
- splitLoop :: (Word# -> Bool)
- -> Ptr Word8
- -> Int -> Int -> Int
- -> ForeignPtr Word8
- -> IO [ByteString]
-
- splitLoop pred' p idx' off' len' fp'
- | pred' `seq` p `seq` idx' `seq` off' `seq` len' `seq` fp' `seq` False = undefined
- | idx' >= len' = return [PS fp' off' idx']
- | otherwise = do
- w <- peekElemOff p (off'+idx')
- if pred' (case w of W8# w# -> w#)
- then return (PS fp' off' idx' :
- splitWith0 pred' (off'+idx'+1) (len'-idx'-1) fp')
- else splitLoop pred' p (idx'+1) off' len' fp'
-{-# INLINE splitWith #-}
-
-#else
-splitWith _ (PS _ _ 0) = []
-splitWith p ps = loop p ps
- where
- STRICT2(loop)
- loop q qs = if null rest then [chunk]
- else chunk : loop q (unsafeTail rest)
- where (chunk,rest) = break q qs
-#endif
-
--- | /O(n)/ Break a 'ByteString' into pieces separated by the byte
--- argument, consuming the delimiter. I.e.
---
--- > split '\n' "a\nb\nd\ne" == ["a","b","d","e"]
--- > split 'a' "aXaXaXa" == ["","X","X","X",""]
--- > split 'x' "x" == ["",""]
---
--- and
---
--- > join [c] . split c == id
--- > split == splitWith . (==)
---
--- As for all splitting functions in this library, this function does
--- not copy the substrings, it just constructs new 'ByteStrings' that
--- are slices of the original.
---
-split :: Word8 -> ByteString -> [ByteString]
-split _ (PS _ _ 0) = []
-split w (PS x s l) = inlinePerformIO $ withForeignPtr x $ \p -> do
- let ptr = p `plusPtr` s
-
- STRICT1(loop)
- loop n =
- let q = inlinePerformIO $ memchr (ptr `plusPtr` n)
- w (fromIntegral (l-n))
- in if q == nullPtr
- then [PS x (s+n) (l-n)]
- else let i = q `minusPtr` ptr in PS x (s+n) (i-n) : loop (i+1)
-
- return (loop 0)
-{-# INLINE split #-}
-
-{-
--- slower. but stays inside Haskell.
-split _ (PS _ _ 0) = []
-split (W8# w#) (PS fp off len) = splitWith' off len fp
- where
- splitWith' off' len' fp' = withPtr fp $ \p ->
- splitLoop p 0 off' len' fp'
-
- splitLoop :: Ptr Word8
- -> Int -> Int -> Int
- -> ForeignPtr Word8
- -> IO [ByteString]
-
- STRICT5(splitLoop)
- splitLoop p idx' off' len' fp'
- | p `seq` idx' `seq` off' `seq` len' `seq` fp' `seq` False = undefined
- | idx' >= len' = return [PS fp' off' idx']
- | otherwise = do
- (W8# x#) <- peekElemOff p (off'+idx')
- if word2Int# w# ==# word2Int# x#
- then return (PS fp' off' idx' :
- splitWith' (off'+idx'+1) (len'-idx'-1) fp')
- else splitLoop p (idx'+1) off' len' fp'
--}
-
-{-
--- | Like 'splitWith', except that sequences of adjacent separators are
--- treated as a single separator. eg.
---
--- > tokens (=='a') "aabbaca" == ["bb","c"]
---
-tokens :: (Word8 -> Bool) -> ByteString -> [ByteString]
-tokens f = P.filter (not.null) . splitWith f
-{-# INLINE tokens #-}
--}
-
--- | The 'group' function takes a ByteString and returns a list of
--- ByteStrings such that the concatenation of the result is equal to the
--- argument. Moreover, each sublist in the result contains only equal
--- elements. For example,
---
--- > group "Mississippi" = ["M","i","ss","i","ss","i","pp","i"]
---
--- It is a special case of 'groupBy', which allows the programmer to
--- supply their own equality test. It is about 40% faster than
--- /groupBy (==)/
-group :: ByteString -> [ByteString]
-group xs
- | null xs = []
- | otherwise = ys : group zs
- where
- (ys, zs) = spanByte (unsafeHead xs) xs
-
--- | The 'groupBy' function is the non-overloaded version of 'group'.
-groupBy :: (Word8 -> Word8 -> Bool) -> ByteString -> [ByteString]
-groupBy k xs
- | null xs = []
- | otherwise = unsafeTake n xs : groupBy k (unsafeDrop n xs)
- where
- n = 1 + findIndexOrEnd (not . k (unsafeHead xs)) (unsafeTail xs)
-
--- | /O(n)/ The 'join' function takes a 'ByteString' and a list of
--- 'ByteString's and concatenates the list after interspersing the first
--- argument between each element of the list.
-join :: ByteString -> [ByteString] -> ByteString
-join s = concat . (List.intersperse s)
-{-# INLINE [1] join #-}
-
-{-# RULES
-"FPS specialise join c -> joinByte" forall c s1 s2 .
- join (singleton c) (s1 : s2 : []) = joinWithByte c s1 s2
- #-}
-
---
--- | /O(n)/ joinWithByte. An efficient way to join to two ByteStrings
--- with a char. Around 4 times faster than the generalised join.
---
-joinWithByte :: Word8 -> ByteString -> ByteString -> ByteString
-joinWithByte c f@(PS ffp s l) g@(PS fgp t m) = unsafeCreate len $ \ptr ->
- withForeignPtr ffp $ \fp ->
- withForeignPtr fgp $ \gp -> do
- memcpy ptr (fp `plusPtr` s) (fromIntegral l)
- poke (ptr `plusPtr` l) c
- memcpy (ptr `plusPtr` (l + 1)) (gp `plusPtr` t) (fromIntegral m)
- where
- len = length f + length g + 1
-{-# INLINE joinWithByte #-}
-
--- ---------------------------------------------------------------------
--- Indexing ByteStrings
-
--- | /O(1)/ 'ByteString' index (subscript) operator, starting from 0.
-index :: ByteString -> Int -> Word8
-index ps n
- | n < 0 = moduleError "index" ("negative index: " ++ show n)
- | n >= length ps = moduleError "index" ("index too large: " ++ show n
- ++ ", length = " ++ show (length ps))
- | otherwise = ps `unsafeIndex` n
-{-# INLINE index #-}
-
--- | /O(n)/ The 'elemIndex' function returns the index of the first
--- element in the given 'ByteString' which is equal to the query
--- element, or 'Nothing' if there is no such element.
--- This implementation uses memchr(3).
-elemIndex :: Word8 -> ByteString -> Maybe Int
-elemIndex c (PS x s l) = inlinePerformIO $ withForeignPtr x $ \p -> do
- let p' = p `plusPtr` s
- q <- memchr p' c (fromIntegral l)
- return $! if q == nullPtr then Nothing else Just $! q `minusPtr` p'
-{-# INLINE elemIndex #-}
-
--- | /O(n)/ The 'elemIndexEnd' function returns the last index of the
--- element in the given 'ByteString' which is equal to the query
--- element, or 'Nothing' if there is no such element. The following
--- holds:
---
--- > elemIndexEnd c xs ==
--- > (-) (length xs - 1) `fmap` elemIndex c (reverse xs)
---
-elemIndexEnd :: Word8 -> ByteString -> Maybe Int
-elemIndexEnd ch (PS x s l) = inlinePerformIO $ withForeignPtr x $ \p ->
- go (p `plusPtr` s) (l-1)
- where
- STRICT2(go)
- go p i | i < 0 = return Nothing
- | otherwise = do ch' <- peekByteOff p i
- if ch == ch'
- then return $ Just i
- else go p (i-1)
-{-# INLINE elemIndexEnd #-}
-
--- | /O(n)/ The 'elemIndices' function extends 'elemIndex', by returning
--- the indices of all elements equal to the query element, in ascending order.
--- This implementation uses memchr(3).
-elemIndices :: Word8 -> ByteString -> [Int]
-elemIndices w (PS x s l) = inlinePerformIO $ withForeignPtr x $ \p -> do
- let ptr = p `plusPtr` s
-
- STRICT1(loop)
- loop n = let q = inlinePerformIO $ memchr (ptr `plusPtr` n)
- w (fromIntegral (l - n))
- in if q == nullPtr
- then []
- else let i = q `minusPtr` ptr
- in i : loop (i+1)
- return $! loop 0
-{-# INLINE elemIndices #-}
-
-{-
--- much slower
-elemIndices :: Word8 -> ByteString -> [Int]
-elemIndices c ps = loop 0 ps
- where STRICT2(loop)
- loop _ ps' | null ps' = []
- loop n ps' | c == unsafeHead ps' = n : loop (n+1) (unsafeTail ps')
- | otherwise = loop (n+1) (unsafeTail ps')
--}
-
--- | count returns the number of times its argument appears in the ByteString
---
--- > count = length . elemIndices
---
--- But more efficiently than using length on the intermediate list.
-count :: Word8 -> ByteString -> Int
-count w (PS x s m) = inlinePerformIO $ withForeignPtr x $ \p ->
- fmap fromIntegral $ c_count (p `plusPtr` s) (fromIntegral m) w
-{-# INLINE count #-}
-
-{-
---
--- around 30% slower
---
-count w (PS x s m) = inlinePerformIO $ withForeignPtr x $ \p ->
- go (p `plusPtr` s) (fromIntegral m) 0
- where
- go :: Ptr Word8 -> CSize -> Int -> IO Int
- STRICT3(go)
- go p l i = do
- q <- memchr p w l
- if q == nullPtr
- then return i
- else do let k = fromIntegral $ q `minusPtr` p
- go (q `plusPtr` 1) (l-k-1) (i+1)
--}
-
--- | The 'findIndex' function takes a predicate and a 'ByteString' and
--- returns the index of the first element in the ByteString
--- satisfying the predicate.
-findIndex :: (Word8 -> Bool) -> ByteString -> Maybe Int
-findIndex k (PS x s l) = inlinePerformIO $ withForeignPtr x $ \f -> go (f `plusPtr` s) 0
- where
- STRICT2(go)
- go ptr n | n >= l = return Nothing
- | otherwise = do w <- peek ptr
- if k w
- then return (Just n)
- else go (ptr `plusPtr` 1) (n+1)
-{-# INLINE findIndex #-}
-
--- | The 'findIndices' function extends 'findIndex', by returning the
--- indices of all elements satisfying the predicate, in ascending order.
-findIndices :: (Word8 -> Bool) -> ByteString -> [Int]
-findIndices p ps = loop 0 ps
- where
- STRICT2(loop)
- loop n qs | null qs = []
- | p (unsafeHead qs) = n : loop (n+1) (unsafeTail qs)
- | otherwise = loop (n+1) (unsafeTail qs)
-
--- ---------------------------------------------------------------------
--- Searching ByteStrings
-
--- | /O(n)/ 'elem' is the 'ByteString' membership predicate.
-elem :: Word8 -> ByteString -> Bool
-elem c ps = case elemIndex c ps of Nothing -> False ; _ -> True
-{-# INLINE elem #-}
-
--- | /O(n)/ 'notElem' is the inverse of 'elem'
-notElem :: Word8 -> ByteString -> Bool
-notElem c ps = not (elem c ps)
-{-# INLINE notElem #-}
-
--- | /O(n)/ 'filter', applied to a predicate and a ByteString,
--- returns a ByteString containing those characters that satisfy the
--- predicate. This function is subject to array fusion.
-filter :: (Word8 -> Bool) -> ByteString -> ByteString
-#if defined(LOOPU_FUSION)
-filter p = loopArr . loopU (filterEFL p) NoAcc
-#elif defined(LOOPUP_FUSION)
-filter p = loopArr . loopUp (filterEFL p) NoAcc
-#elif defined(LOOPNOACC_FUSION)
-filter p = loopArr . loopNoAcc (filterEFL p)
-#else
-filter f = loopArr . loopFilter f
-#endif
-{-# INLINE filter #-}
-
-{-
--- | /O(n)/ 'filter\'' is a non-fuseable version of filter, that may be
--- around 2x faster for some one-shot applications.
-filter' :: (Word8 -> Bool) -> ByteString -> ByteString
-filter' k ps@(PS x s l)
- | null ps = ps
- | otherwise = unsafePerformIO $ createAndTrim l $ \p -> withForeignPtr x $ \f -> do
- t <- go (f `plusPtr` s) p (f `plusPtr` (s + l))
- return $! t `minusPtr` p -- actual length
- where
- STRICT3(go)
- go f t end | f == end = return t
- | otherwise = do
- w <- peek f
- if k w
- then poke t w >> go (f `plusPtr` 1) (t `plusPtr` 1) end
- else go (f `plusPtr` 1) t end
-{-# INLINE filter' #-}
--}
-
---
--- | /O(n)/ A first order equivalent of /filter . (==)/, for the common
--- case of filtering a single byte. It is more efficient to use
--- /filterByte/ in this case.
---
--- > filterByte == filter . (==)
---
--- filterByte is around 10x faster, and uses much less space, than its
--- filter equivalent
-filterByte :: Word8 -> ByteString -> ByteString
-filterByte w ps = replicate (count w ps) w
-{-# INLINE filterByte #-}
-
-{-# RULES
- "FPS specialise filter (== x)" forall x.
- filter ((==) x) = filterByte x
- #-}
-
-#if __GLASGOW_HASKELL__ >= 605
-{-# RULES
- "FPS specialise filter (== x)" forall x.
- filter (== x) = filterByte x
- #-}
-#endif
-
---
--- | /O(n)/ A first order equivalent of /filter . (\/=)/, for the common
--- case of filtering a single byte out of a list. It is more efficient
--- to use /filterNotByte/ in this case.
---
--- > filterNotByte == filter . (/=)
---
--- filterNotByte is around 2x faster than its filter equivalent.
-filterNotByte :: Word8 -> ByteString -> ByteString
-filterNotByte w = filter (/= w)
-{-# INLINE filterNotByte #-}
-
-{-# RULES
-"FPS specialise filter (x /=)" forall x.
- filter ((/=) x) = filterNotByte x
- #-}
-
-#if __GLASGOW_HASKELL__ >= 605
-{-# RULES
-"FPS specialise filter (/= x)" forall x.
- filter (/= x) = filterNotByte x
- #-}
-#endif
-
--- | /O(n)/ The 'find' function takes a predicate and a ByteString,
--- and returns the first element in matching the predicate, or 'Nothing'
--- if there is no such element.
---
--- > find f p = case findIndex f p of Just n -> Just (p ! n) ; _ -> Nothing
---
-find :: (Word8 -> Bool) -> ByteString -> Maybe Word8
-find f p = case findIndex f p of
- Just n -> Just (p `unsafeIndex` n)
- _ -> Nothing
-{-# INLINE find #-}
-
-{-
---
--- fuseable, but we don't want to walk the whole array.
---
-find k = foldl findEFL Nothing
- where findEFL a@(Just _) _ = a
- findEFL _ c | k c = Just c
- | otherwise = Nothing
--}
-
--- ---------------------------------------------------------------------
--- Searching for substrings
-
--- | /O(n)/ The 'isPrefixOf' function takes two ByteStrings and returns 'True'
--- iff the first is a prefix of the second.
-isPrefixOf :: ByteString -> ByteString -> Bool
-isPrefixOf (PS x1 s1 l1) (PS x2 s2 l2)
- | l1 == 0 = True
- | l2 < l1 = False
- | otherwise = inlinePerformIO $ withForeignPtr x1 $ \p1 ->
- withForeignPtr x2 $ \p2 -> do
- i <- memcmp (p1 `plusPtr` s1) (p2 `plusPtr` s2) (fromIntegral l1)
- return $! i == 0
-
--- | /O(n)/ The 'isSuffixOf' function takes two ByteStrings and returns 'True'
--- iff the first is a suffix of the second.
---
--- The following holds:
---
--- > isSuffixOf x y == reverse x `isPrefixOf` reverse y
---
--- However, the real implemenation uses memcmp to compare the end of the
--- string only, with no reverse required..
-isSuffixOf :: ByteString -> ByteString -> Bool
-isSuffixOf (PS x1 s1 l1) (PS x2 s2 l2)
- | l1 == 0 = True
- | l2 < l1 = False
- | otherwise = inlinePerformIO $ withForeignPtr x1 $ \p1 ->
- withForeignPtr x2 $ \p2 -> do
- i <- memcmp (p1 `plusPtr` s1) (p2 `plusPtr` s2 `plusPtr` (l2 - l1)) (fromIntegral l1)
- return $! i == 0
-
--- | Check whether one string is a substring of another. @isSubstringOf
--- p s@ is equivalent to @not (null (findSubstrings p s))@.
-isSubstringOf :: ByteString -- ^ String to search for.
- -> ByteString -- ^ String to search in.
- -> Bool
-isSubstringOf p s = not $ P.null $ findSubstrings p s
-
--- | Get the first index of a substring in another string,
--- or 'Nothing' if the string is not found.
--- @findSubstring p s@ is equivalent to @listToMaybe (findSubstrings p s)@.
-findSubstring :: ByteString -- ^ String to search for.
- -> ByteString -- ^ String to seach in.
- -> Maybe Int
-findSubstring = (listToMaybe .) . findSubstrings
-
--- | Find the indexes of all (possibly overlapping) occurances of a
--- substring in a string. This function uses the Knuth-Morris-Pratt
--- string matching algorithm.
-findSubstrings :: ByteString -- ^ String to search for.
- -> ByteString -- ^ String to seach in.
- -> [Int]
-
-findSubstrings pat@(PS _ _ m) str@(PS _ _ n) = search 0 0
- where
- patc x = pat `unsafeIndex` x
- strc x = str `unsafeIndex` x
-
- -- maybe we should make kmpNext a UArray before using it in search?
- kmpNext = listArray (0,m) (-1:kmpNextL pat (-1))
- kmpNextL p _ | null p = []
- kmpNextL p j = let j' = next (unsafeHead p) j + 1
- ps = unsafeTail p
- x = if not (null ps) && unsafeHead ps == patc j'
- then kmpNext Array.! j' else j'
- in x:kmpNextL ps j'
- search i j = match ++ rest -- i: position in string, j: position in pattern
- where match = if j == m then [(i - j)] else []
- rest = if i == n then [] else search (i+1) (next (strc i) j + 1)
- next c j | j >= 0 && (j == m || c /= patc j) = next c (kmpNext Array.! j)
- | otherwise = j
-
--- ---------------------------------------------------------------------
--- Zipping
-
--- | /O(n)/ 'zip' takes two ByteStrings and returns a list of
--- corresponding pairs of bytes. If one input ByteString is short,
--- excess elements of the longer ByteString are discarded. This is
--- equivalent to a pair of 'unpack' operations.
-zip :: ByteString -> ByteString -> [(Word8,Word8)]
-zip ps qs
- | null ps || null qs = []
- | otherwise = (unsafeHead ps, unsafeHead qs) : zip (unsafeTail ps) (unsafeTail qs)
-
--- | 'zipWith' generalises 'zip' by zipping with the function given as
--- the first argument, instead of a tupling function. For example,
--- @'zipWith' (+)@ is applied to two ByteStrings to produce the list of
--- corresponding sums.
-zipWith :: (Word8 -> Word8 -> a) -> ByteString -> ByteString -> [a]
-zipWith f ps qs
- | null ps || null qs = []
- | otherwise = f (unsafeHead ps) (unsafeHead qs) : zipWith f (unsafeTail ps) (unsafeTail qs)
-#if defined(__GLASGOW_HASKELL__)
-{-# INLINE [1] zipWith #-}
-#endif
-
---
--- | A specialised version of zipWith for the common case of a
--- simultaneous map over two bytestrings, to build a 3rd. Rewrite rules
--- are used to automatically covert zipWith into zipWith' when a pack is
--- performed on the result of zipWith, but we also export it for
--- convenience.
---
-zipWith' :: (Word8 -> Word8 -> Word8) -> ByteString -> ByteString -> ByteString
-zipWith' f (PS fp s l) (PS fq t m) = inlinePerformIO $
- withForeignPtr fp $ \a ->
- withForeignPtr fq $ \b ->
- create len $ zipWith_ 0 (a `plusPtr` s) (b `plusPtr` t)
- where
- zipWith_ :: Int -> Ptr Word8 -> Ptr Word8 -> Ptr Word8 -> IO ()
- STRICT4(zipWith_)
- zipWith_ n p1 p2 r
- | n >= len = return ()
- | otherwise = do
- x <- peekByteOff p1 n
- y <- peekByteOff p2 n
- pokeByteOff r n (f x y)
- zipWith_ (n+1) p1 p2 r
-
- len = min l m
-{-# INLINE zipWith' #-}
-
-{-# RULES
-
-"FPS specialise zipWith" forall (f :: Word8 -> Word8 -> Word8) p q .
- zipWith f p q = unpack (zipWith' f p q)
-
- #-}
-
--- | /O(n)/ 'unzip' transforms a list of pairs of bytes into a pair of
--- ByteStrings. Note that this performs two 'pack' operations.
-unzip :: [(Word8,Word8)] -> (ByteString,ByteString)
-unzip ls = (pack (P.map fst ls), pack (P.map snd ls))
-{-# INLINE unzip #-}
-
--- ---------------------------------------------------------------------
--- Special lists
-
--- | /O(n)/ Return all initial segments of the given 'ByteString', shortest first.
-inits :: ByteString -> [ByteString]
-inits (PS x s l) = [PS x s n | n <- [0..l]]
-
--- | /O(n)/ Return all final segments of the given 'ByteString', longest first.
-tails :: ByteString -> [ByteString]
-tails p | null p = [empty]
- | otherwise = p : tails (unsafeTail p)
-
--- less efficent spacewise: tails (PS x s l) = [PS x (s+n) (l-n) | n <- [0..l]]
-
--- ---------------------------------------------------------------------
--- ** Ordered 'ByteString's
-
--- | /O(n)/ Sort a ByteString efficiently, using counting sort.
-sort :: ByteString -> ByteString
-sort (PS input s l) = unsafeCreate l $ \p -> allocaArray 256 $ \arr -> do
-
- memset (castPtr arr) 0 (256 * fromIntegral (sizeOf (undefined :: CSize)))
- withForeignPtr input (\x -> countOccurrences arr (x `plusPtr` s) l)
-
- let STRICT2(go)
- go 256 _ = return ()
- go i ptr = do n <- peekElemOff arr i
- when (n /= 0) $ memset ptr (fromIntegral i) n >> return ()
- go (i + 1) (ptr `plusPtr` (fromIntegral n))
- go 0 p
-
-{-
-sort :: ByteString -> ByteString
-sort (PS x s l) = unsafeCreate l $ \p -> withForeignPtr x $ \f -> do
- memcpy p (f `plusPtr` s) l
- c_qsort p l -- inplace
--}
-
--- | The 'sortBy' function is the non-overloaded version of 'sort'.
---
--- Try some linear sorts: radix, counting
--- Or mergesort.
---
--- sortBy :: (Word8 -> Word8 -> Ordering) -> ByteString -> ByteString
--- sortBy f ps = undefined
-
--- ---------------------------------------------------------------------
--- Low level constructors
-
--- | /O(n)/ Build a @ByteString@ from a @CString@. This value will have /no/
--- finalizer associated to it. The ByteString length is calculated using
--- /strlen(3)/, and thus the complexity is a /O(n)/.
-packCString :: CString -> ByteString
-packCString cstr = unsafePerformIO $ do
- fp <- newForeignPtr_ (castPtr cstr)
- l <- c_strlen cstr
- return $! PS fp 0 (fromIntegral l)
-
--- | /O(1)/ Build a @ByteString@ from a @CStringLen@. This value will
--- have /no/ finalizer associated with it. This operation has /O(1)/
--- complexity as we already know the final size, so no /strlen(3)/ is
--- required.
-packCStringLen :: CStringLen -> ByteString
-packCStringLen (ptr,len) = unsafePerformIO $ do
- fp <- newForeignPtr_ (castPtr ptr)
- return $! PS fp 0 (fromIntegral len)
-
--- | /O(n)/ Build a @ByteString@ from a malloced @CString@. This value will
--- have a @free(3)@ finalizer associated to it.
-packMallocCString :: CString -> ByteString
-packMallocCString cstr = unsafePerformIO $ do
- fp <- newForeignFreePtr (castPtr cstr)
- len <- c_strlen cstr
- return $! PS fp 0 (fromIntegral len)
-
--- | /O(n) construction/ Use a @ByteString@ with a function requiring a
--- null-terminated @CString@. The @CString@ will be freed
--- automatically. This is a memcpy(3).
-useAsCString :: ByteString -> (CString -> IO a) -> IO a
-useAsCString (PS ps s l) = bracket alloc (c_free.castPtr)
- where alloc = withForeignPtr ps $ \p -> do
- buf <- c_malloc (fromIntegral l+1)
- memcpy (castPtr buf) (castPtr p `plusPtr` s) (fromIntegral l)
- poke (buf `plusPtr` l) (0::Word8) -- n.b.
- return (castPtr buf)
-
--- | /O(1) construction/ Use a @ByteString@ with a function requiring a @CStringLen@.
-useAsCStringLen :: ByteString -> (CStringLen -> IO a) -> IO a
-useAsCStringLen = unsafeUseAsCStringLen
-
---
--- why were we doing this?
---
--- useAsCStringLen :: ByteString -> (CStringLen -> IO a) -> IO a
--- useAsCStringLen (PS ps s l) = bracket alloc (c_free.castPtr.fst)
--- where
--- alloc = withForeignPtr ps $ \p -> do
--- buf <- c_malloc (fromIntegral l+1)
--- memcpy (castPtr buf) (castPtr p `plusPtr` s) (fromIntegral l)
--- poke (buf `plusPtr` l) (0::Word8) -- n.b.
--- return $! (castPtr buf, l)
---
-
--- | /O(n)/ Make a copy of the 'ByteString' with its own storage.
--- This is mainly useful to allow the rest of the data pointed
--- to by the 'ByteString' to be garbage collected, for example
--- if a large string has been read in, and only a small part of it
--- is needed in the rest of the program.
-copy :: ByteString -> ByteString
-copy (PS x s l) = unsafeCreate l $ \p -> withForeignPtr x $ \f ->
- memcpy p (f `plusPtr` s) (fromIntegral l)
-
--- | /O(n)/ Duplicate a CString as a ByteString. Useful if you know the
--- CString is going to be deallocated from C land.
-copyCString :: CString -> IO ByteString
-copyCString cstr = do
- len <- c_strlen cstr
- copyCStringLen (cstr, fromIntegral len)
-
--- | /O(n)/ Same as copyCString, but saves a strlen call when the length is known.
-copyCStringLen :: CStringLen -> IO ByteString
-copyCStringLen (cstr, len) = create len $ \p ->
- memcpy p (castPtr cstr) (fromIntegral len)
-
--- ---------------------------------------------------------------------
--- line IO
-
--- | Read a line from stdin.
-getLine :: IO ByteString
-getLine = hGetLine stdin
-
-{-
--- | Lazily construct a list of lines of ByteStrings. This will be much
--- better on memory consumption than using 'hGetContents >>= lines'
--- If you're considering this, a better choice might be to use
--- Data.ByteString.Lazy
-hGetLines :: Handle -> IO [ByteString]
-hGetLines h = go
- where
- go = unsafeInterleaveIO $ do
- e <- hIsEOF h
- if e
- then return []
- else do
- x <- hGetLine h
- xs <- go
- return (x:xs)
--}
-
--- | Read a line from a handle
-
-hGetLine :: Handle -> IO ByteString
-#if !defined(__GLASGOW_HASKELL__)
-hGetLine h = System.IO.hGetLine h >>= return . pack . P.map c2w
-#else
-hGetLine h = wantReadableHandle "Data.ByteString.hGetLine" h $ \ handle_ -> do
- case haBufferMode handle_ of
- NoBuffering -> error "no buffering"
- _other -> hGetLineBuffered handle_
-
- where
- hGetLineBuffered handle_ = do
- let ref = haBuffer handle_
- buf <- readIORef ref
- hGetLineBufferedLoop handle_ ref buf 0 []
-
- hGetLineBufferedLoop handle_ ref
- buf@Buffer{ bufRPtr=r, bufWPtr=w, bufBuf=raw } len xss =
- len `seq` do
- off <- findEOL r w raw
- let new_len = len + off - r
- xs <- mkPS raw r off
-
- -- if eol == True, then off is the offset of the '\n'
- -- otherwise off == w and the buffer is now empty.
- if off /= w
- then do if (w == off + 1)
- then writeIORef ref buf{ bufRPtr=0, bufWPtr=0 }
- else writeIORef ref buf{ bufRPtr = off + 1 }
- mkBigPS new_len (xs:xss)
- else do
- maybe_buf <- maybeFillReadBuffer (haFD handle_) True (haIsStream handle_)
- buf{ bufWPtr=0, bufRPtr=0 }
- case maybe_buf of
- -- Nothing indicates we caught an EOF, and we may have a
- -- partial line to return.
- Nothing -> do
- writeIORef ref buf{ bufRPtr=0, bufWPtr=0 }
- if new_len > 0
- then mkBigPS new_len (xs:xss)
- else ioe_EOF
- Just new_buf ->
- hGetLineBufferedLoop handle_ ref new_buf new_len (xs:xss)
-
- -- find the end-of-line character, if there is one
- findEOL r w raw
- | r == w = return w
- | otherwise = do
- (c,r') <- readCharFromBuffer raw r
- if c == '\n'
- then return r -- NB. not r': don't include the '\n'
- else findEOL r' w raw
-
- maybeFillReadBuffer fd is_line is_stream buf = catch
- (do buf' <- fillReadBuffer fd is_line is_stream buf
- return (Just buf'))
- (\e -> if isEOFError e then return Nothing else ioError e)
-
--- TODO, rewrite to use normal memcpy
-mkPS :: RawBuffer -> Int -> Int -> IO ByteString
-mkPS buf start end =
- let len = end - start
- in create len $ \p -> do
- memcpy_ptr_baoff p buf (fromIntegral start) (fromIntegral len)
- return ()
-
-mkBigPS :: Int -> [ByteString] -> IO ByteString
-mkBigPS _ [ps] = return ps
-mkBigPS _ pss = return $! concat (P.reverse pss)
-
-#endif
-
--- ---------------------------------------------------------------------
--- Block IO
-
--- | Outputs a 'ByteString' to the specified 'Handle'.
-hPut :: Handle -> ByteString -> IO ()
-hPut _ (PS _ _ 0) = return ()
-hPut h (PS ps s l) = withForeignPtr ps $ \p-> hPutBuf h (p `plusPtr` s) l
-
--- | A synonym for @hPut@, for compatibility
-hPutStr :: Handle -> ByteString -> IO ()
-hPutStr = hPut
-
--- | Write a ByteString to a handle, appending a newline byte
-hPutStrLn :: Handle -> ByteString -> IO ()
-hPutStrLn h ps
- | length ps < 1024 = hPut h (ps `snoc` 0x0a)
- | otherwise = hPut h ps >> hPut h (singleton (0x0a)) -- don't copy
-
--- | Write a ByteString to stdout
-putStr :: ByteString -> IO ()
-putStr = hPut stdout
-
--- | Write a ByteString to stdout, appending a newline byte
-putStrLn :: ByteString -> IO ()
-putStrLn = hPutStrLn stdout
-
--- | Read a 'ByteString' directly from the specified 'Handle'. This
--- is far more efficient than reading the characters into a 'String'
--- and then using 'pack'.
-hGet :: Handle -> Int -> IO ByteString
-hGet _ 0 = return empty
-hGet h i = createAndTrim i $ \p -> hGetBuf h p i
-
--- | hGetNonBlocking is identical to 'hGet', except that it will never block
--- waiting for data to become available, instead it returns only whatever data
--- is available.
-hGetNonBlocking :: Handle -> Int -> IO ByteString
-#if defined(__GLASGOW_HASKELL__)
-hGetNonBlocking _ 0 = return empty
-hGetNonBlocking h i = createAndTrim i $ \p -> hGetBufNonBlocking h p i
-#else
-hGetNonBlocking = hGet
-#endif
-
--- | Read entire handle contents into a 'ByteString'.
--- This function reads chunks at a time, doubling the chunksize on each
--- read. The final buffer is then realloced to the appropriate size. For
--- files > half of available memory, this may lead to memory exhaustion.
--- Consider using 'readFile' in this case.
---
--- As with 'hGet', the string representation in the file is assumed to
--- be ISO-8859-1.
---
-hGetContents :: Handle -> IO ByteString
-hGetContents h = do
- let start_size = 1024
- p <- mallocArray start_size
- i <- hGetBuf h p start_size
- if i < start_size
- then do p' <- reallocArray p i
- fp <- newForeignFreePtr p'
- return $! PS fp 0 i
- else f p start_size
- where
- f p s = do
- let s' = 2 * s
- p' <- reallocArray p s'
- i <- hGetBuf h (p' `plusPtr` s) s
- if i < s
- then do let i' = s + i
- p'' <- reallocArray p' i'
- fp <- newForeignFreePtr p''
- return $! PS fp 0 i'
- else f p' s'
-
--- | getContents. Equivalent to hGetContents stdin
-getContents :: IO ByteString
-getContents = hGetContents stdin
-
--- | The interact function takes a function of type @ByteString -> ByteString@
--- as its argument. The entire input from the standard input device is passed
--- to this function as its argument, and the resulting string is output on the
--- standard output device. It's great for writing one line programs!
-interact :: (ByteString -> ByteString) -> IO ()
-interact transformer = putStr . transformer =<< getContents
-
--- | Read an entire file strictly into a 'ByteString'. This is far more
--- efficient than reading the characters into a 'String' and then using
--- 'pack'. It also may be more efficient than opening the file and
--- reading it using hGet. Files are read using 'binary mode' on Windows,
--- for 'text mode' use the Char8 version of this function.
-readFile :: FilePath -> IO ByteString
-readFile f = bracket (openBinaryFile f ReadMode) hClose
- (\h -> hFileSize h >>= hGet h . fromIntegral)
-
--- | Write a 'ByteString' to a file.
-writeFile :: FilePath -> ByteString -> IO ()
-writeFile f txt = bracket (openBinaryFile f WriteMode) hClose
- (\h -> hPut h txt)
-
--- | Append a 'ByteString' to a file.
-appendFile :: FilePath -> ByteString -> IO ()
-appendFile f txt = bracket (openBinaryFile f AppendMode) hClose
- (\h -> hPut h txt)
-
-{-
---
--- Disable until we can move it into a portable .hsc file
---
-
--- | Like readFile, this reads an entire file directly into a
--- 'ByteString', but it is even more efficient. It involves directly
--- mapping the file to memory. This has the advantage that the contents
--- of the file never need to be copied. Also, under memory pressure the
--- page may simply be discarded, while in the case of readFile it would
--- need to be written to swap. If you read many small files, mmapFile
--- will be less memory-efficient than readFile, since each mmapFile
--- takes up a separate page of memory. Also, you can run into bus
--- errors if the file is modified. As with 'readFile', the string
--- representation in the file is assumed to be ISO-8859-1.
---
--- On systems without mmap, this is the same as a readFile.
---
-mmapFile :: FilePath -> IO ByteString
-mmapFile f = mmap f >>= \(fp,l) -> return $! PS fp 0 l
-
-mmap :: FilePath -> IO (ForeignPtr Word8, Int)
-mmap f = do
- h <- openBinaryFile f ReadMode
- l <- fromIntegral `fmap` hFileSize h
- -- Don't bother mmaping small files because each mmapped file takes up
- -- at least one full VM block.
- if l < mmap_limit
- then do thefp <- mallocByteString l
- withForeignPtr thefp $ \p-> hGetBuf h p l
- hClose h
- return (thefp, l)
- else do
- -- unix only :(
- fd <- fromIntegral `fmap` handleToFd h
- p <- my_mmap l fd
- fp <- if p == nullPtr
- then do thefp <- mallocByteString l
- withForeignPtr thefp $ \p' -> hGetBuf h p' l
- return thefp
- else do
- -- The munmap leads to crashes on OpenBSD.
- -- maybe there's a use after unmap in there somewhere?
- -- Bulat suggests adding the hClose to the
- -- finalizer, excellent idea.
-#if !defined(__OpenBSD__)
- let unmap = c_munmap p l >> return ()
-#else
- let unmap = return ()
-#endif
- fp <- newForeignPtr p unmap
- return fp
- c_close fd
- hClose h
- return (fp, l)
- where mmap_limit = 16*1024
--}
-
--- ---------------------------------------------------------------------
--- Internal utilities
-
--- | 'findIndexOrEnd' is a variant of findIndex, that returns the length
--- of the string if no element is found, rather than Nothing.
-findIndexOrEnd :: (Word8 -> Bool) -> ByteString -> Int
-findIndexOrEnd k (PS x s l) = inlinePerformIO $ withForeignPtr x $ \f -> go (f `plusPtr` s) 0
- where
- STRICT2(go)
- go ptr n | n >= l = return l
- | otherwise = do w <- peek ptr
- if k w
- then return n
- else go (ptr `plusPtr` 1) (n+1)
-{-# INLINE findIndexOrEnd #-}
-
--- | Perform an operation with a temporary ByteString
-withPtr :: ForeignPtr a -> (Ptr a -> IO b) -> b
-withPtr fp io = inlinePerformIO (withForeignPtr fp io)
-{-# INLINE withPtr #-}
-
--- Common up near identical calls to `error' to reduce the number
--- constant strings created when compiled:
-errorEmptyList :: String -> a
-errorEmptyList fun = moduleError fun "empty ByteString"
-{-# NOINLINE errorEmptyList #-}
-
-moduleError :: String -> String -> a
-moduleError fun msg = error ("Data.ByteString." ++ fun ++ ':':' ':msg)
-{-# NOINLINE moduleError #-}
-
--- Find from the end of the string using predicate
-findFromEndUntil :: (Word8 -> Bool) -> ByteString -> Int
-STRICT2(findFromEndUntil)
-findFromEndUntil f ps@(PS x s l) =
- if null ps then 0
- else if f (last ps) then l
- else findFromEndUntil f (PS x s (l-1))
-
-{-# INLINE newForeignFreePtr #-}
-newForeignFreePtr :: Ptr Word8 -> IO (ForeignPtr Word8)
-newForeignFreePtr p = newForeignPtr c_free_finalizer p
projects / haskell-directory.git / blobdiff