{-# OPTIONS_GHC -cpp -fglasgow-exts #-}
---
+-- |
-- Module : Data.ByteString.Char8
-- Copyright : (c) Don Stewart 2006
-- License : BSD-style
--
-- Maintainer : dons@cse.unsw.edu.au
-- Stability : experimental
--- Portability : portable (tested with GHC>=6.4.1 and Hugs 2005)
---
-
+-- Portability : portable
--
--- | Manipulate 'ByteString's using 'Char' operations. All Chars will be
+-- Manipulate 'ByteString's using 'Char' operations. All Chars will be
-- truncated to 8 bits. It can be expected that these functions will run
-- at identical speeds to their 'Word8' equivalents in "Data.ByteString".
--
foldl', -- :: (a -> Char -> a) -> a -> ByteString -> a
foldl1, -- :: (Char -> Char -> Char) -> ByteString -> Char
foldl1', -- :: (Char -> Char -> Char) -> ByteString -> Char
+
foldr, -- :: (Char -> a -> a) -> a -> ByteString -> a
+ foldr', -- :: (Char -> a -> a) -> a -> ByteString -> a
foldr1, -- :: (Char -> Char -> Char) -> ByteString -> Char
+ foldr1', -- :: (Char -> Char -> Char) -> ByteString -> Char
-- ** Special folds
concat, -- :: [ByteString] -> ByteString
-- ** Scans
scanl, -- :: (Char -> Char -> Char) -> Char -> ByteString -> ByteString
scanl1, -- :: (Char -> Char -> Char) -> ByteString -> ByteString
--- scanr, -- :: (Char -> Char -> Char) -> Char -> ByteString -> ByteString
--- scanr1, -- :: (Char -> Char -> Char) -> ByteString -> ByteString
+ scanr, -- :: (Char -> Char -> Char) -> Char -> ByteString -> ByteString
+ scanr1, -- :: (Char -> Char -> Char) -> ByteString -> ByteString
-- ** Accumulating maps
--- mapAccumL, -- :: (acc -> Char -> (acc, Char)) -> acc -> ByteString -> (acc, ByteString)
--- mapAccumR, -- :: (acc -> Char -> (acc, Char)) -> acc -> ByteString -> (acc, ByteString)
+ mapAccumL, -- :: (acc -> Char -> (acc, Char)) -> acc -> ByteString -> (acc, ByteString)
+ mapAccumR, -- :: (acc -> Char -> (acc, Char)) -> acc -> ByteString -> (acc, ByteString)
mapIndexed, -- :: (Int -> Char -> Char) -> ByteString -> ByteString
-- * Generating and unfolding ByteStrings
inits, -- :: ByteString -> [ByteString]
tails, -- :: ByteString -> [ByteString]
- -- ** Breaking and dropping on specific Chars
- breakChar, -- :: Char -> ByteString -> (ByteString, ByteString)
- spanChar, -- :: Char -> ByteString -> (ByteString, ByteString)
- breakSpace, -- :: ByteString -> (ByteString,ByteString)
- dropSpace, -- :: ByteString -> ByteString
- dropSpaceEnd, -- :: ByteString -> ByteString
-
-- ** Breaking into many substrings
split, -- :: Char -> ByteString -> [ByteString]
splitWith, -- :: (Char -> Bool) -> ByteString -> [ByteString]
- tokens, -- :: (Char -> Bool) -> ByteString -> [ByteString]
-- ** Breaking into lines and words
lines, -- :: ByteString -> [ByteString]
unlines, -- :: [ByteString] -> ByteString
unwords, -- :: ByteString -> [ByteString]
- lines', -- :: ByteString -> [ByteString]
- unlines', -- :: [ByteString] -> ByteString
- linesCRLF', -- :: ByteString -> [ByteString]
- unlinesCRLF', -- :: [ByteString] -> ByteString
- words', -- :: ByteString -> [ByteString]
- unwords', -- :: ByteString -> [ByteString]
-
- lineIndices, -- :: ByteString -> [Int]
- betweenLines, -- :: ByteString -> ByteString -> ByteString -> Maybe (ByteString)
-
-- ** Joining strings
join, -- :: ByteString -> [ByteString] -> ByteString
- joinWithChar, -- :: Char -> ByteString -> ByteString -> ByteString
-
-- ** Searching for substrings
isPrefixOf, -- :: ByteString -> ByteString -> Bool
-- ** Searching by equality
elem, -- :: Char -> ByteString -> Bool
notElem, -- :: Char -> ByteString -> Bool
- filterChar, -- :: Char -> ByteString -> ByteString
- filterNotChar, -- :: Char -> ByteString -> ByteString
-- ** Searching with a predicate
find, -- :: (Char -> Bool) -> ByteString -> Maybe Char
-- * Ordered ByteStrings
sort, -- :: ByteString -> ByteString
- -- * Conversion
- w2c, -- :: Word8 -> Char
- c2w, -- :: Char -> Word8
-
-- * Reading from ByteStrings
- readInt, -- :: ByteString -> Maybe Int
+ readInt, -- :: ByteString -> Maybe (Int, ByteString)
+ readInteger, -- :: ByteString -> Maybe (Integer, ByteString)
-- * Low level CString conversions
-- * I\/O with @ByteString@s
-- ** Standard input and output
-
-#if defined(__GLASGOW_HASKELL__)
getLine, -- :: IO ByteString
-#endif
getContents, -- :: IO ByteString
putStr, -- :: ByteString -> IO ()
putStrLn, -- :: ByteString -> IO ()
+ interact, -- :: (ByteString -> ByteString) -> IO ()
-- ** Files
readFile, -- :: FilePath -> IO ByteString
-- mmapFile, -- :: FilePath -> IO ByteString
-- ** I\/O with Handles
-#if defined(__GLASGOW_HASKELL__)
- getArgs, -- :: IO [ByteString]
hGetLine, -- :: Handle -> IO ByteString
- hGetLines, -- :: Handle -> IO ByteString
hGetNonBlocking, -- :: Handle -> Int -> IO ByteString
-#endif
hGetContents, -- :: Handle -> IO ByteString
hGet, -- :: Handle -> Int -> IO ByteString
hPut, -- :: Handle -> ByteString -> IO ()
#if defined(__GLASGOW_HASKELL__)
unpackList,
#endif
- filter', map'
) where
,length,map,lines,foldl,foldr,unlines
,concat,any,take,drop,splitAt,takeWhile
,dropWhile,span,break,elem,filter,unwords
- ,words,maximum,minimum,all,concatMap,scanl,scanl1
- ,foldl1,foldr1,readFile,writeFile,appendFile,replicate
- ,getContents,getLine,putStr,putStrLn
+ ,words,maximum,minimum,all,concatMap
+ ,scanl,scanl1,scanr,scanr1
+ ,appendFile,readFile,writeFile
+ ,foldl1,foldr1,replicate
+ ,getContents,getLine,putStr,putStrLn,interact
,zip,zipWith,unzip,notElem)
import qualified Data.ByteString as B
,sort,isPrefixOf,isSuffixOf,isSubstringOf,findSubstring
,findSubstrings,copy,group
- ,getContents, putStr, putStrLn
- ,readFile, {-mmapFile,-} writeFile, appendFile
+ ,getLine, getContents, putStr, putStrLn, interact
,hGetContents, hGet, hPut, hPutStr, hPutStrLn
+ ,hGetLine, hGetNonBlocking
,packCString,packCStringLen, packMallocCString
,useAsCString,useAsCStringLen, copyCString,copyCStringLen
#if defined(__GLASGOW_HASKELL__)
- ,getLine, getArgs, hGetLine, hGetLines, hGetNonBlocking
,unpackList
#endif
)
#if defined(__GLASGOW_HASKELL__)
,packAddress, unsafePackAddress
#endif
- ,c2w, w2c, unsafeTail, inlinePerformIO, isSpaceWord8
+ ,c2w, w2c, unsafeTail, isSpaceWord8, inlinePerformIO
)
+import Data.Char ( isSpace )
import qualified Data.List as List (intersperse)
+import System.IO (openFile,hClose,hFileSize,IOMode(..))
+import Control.Exception (bracket)
import Foreign
#if defined(__GLASGOW_HASKELL__)
writeByte p c = ST $ \s# ->
case writeWord8OffAddr# p 0# c s# of s2# -> (# s2#, () #)
{-# INLINE writeByte #-}
+{-# INLINE [1] pack #-}
{-# RULES
-"pack/packAddress" forall s# .
- pack (unpackCString# s#) = B.packAddress s#
+ "FPS pack/packAddress" forall s .
+ pack (unpackCString# s) = B.packAddress s
#-}
#endif
-{-# INLINE pack #-}
-
-- | /O(n)/ Converts a 'ByteString' to a 'String'.
unpack :: ByteString -> [Char]
-unpack = B.unpackWith w2c
+unpack = P.map w2c . B.unpack
{-# INLINE unpack #-}
-- | /O(n)/ 'cons' is analogous to (:) for lists, but of different
foldr f = B.foldr (\c a -> f (w2c c) a)
{-# INLINE foldr #-}
+-- | 'foldr\'' is a strict variant of foldr
+foldr' :: (Char -> a -> a) -> a -> ByteString -> a
+foldr' f = B.foldr' (\c a -> f (w2c c) a)
+{-# INLINE foldr' #-}
+
-- | 'foldl1' is a variant of 'foldl' that has no starting value
-- argument, and thus must be applied to non-empty 'ByteStrings'.
foldl1 :: (Char -> Char -> Char) -> ByteString -> Char
foldr1 f ps = w2c (B.foldr1 (\x y -> c2w (f (w2c x) (w2c y))) ps)
{-# INLINE foldr1 #-}
+-- | A strict variant of foldr1
+foldr1' :: (Char -> Char -> Char) -> ByteString -> Char
+foldr1' f ps = w2c (B.foldr1' (\x y -> c2w (f (w2c x) (w2c y))) ps)
+{-# INLINE foldr1' #-}
+
-- | Map a function over a 'ByteString' and concatenate the results
concatMap :: (Char -> ByteString) -> ByteString -> ByteString
concatMap f = B.concatMap (f . w2c)
mapIndexed f = B.mapIndexed (\i c -> c2w (f i (w2c c)))
{-# INLINE mapIndexed #-}
+-- | 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 -> Char -> (acc, Char)) -> acc -> ByteString -> (acc, ByteString)
+mapAccumL f = B.mapAccumL (\acc w -> case f acc (w2c w) of (acc', c) -> (acc', c2w c))
+
+-- | 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 -> Char -> (acc, Char)) -> acc -> ByteString -> (acc, ByteString)
+mapAccumR f = B.mapAccumR (\acc w -> case f acc (w2c w) of (acc', c) -> (acc', c2w c))
+
-- | 'scanl' is similar to 'foldl', but returns a list of successive
-- reduced values from the left:
--
scanl1 :: (Char -> Char -> Char) -> ByteString -> ByteString
scanl1 f = B.scanl1 (\a b -> c2w (f (w2c a) (w2c b)))
+-- | scanr is the right-to-left dual of scanl.
+scanr :: (Char -> Char -> Char) -> Char -> ByteString -> ByteString
+scanr f z = B.scanr (\a b -> c2w (f (w2c a) (w2c b))) (c2w z)
+
+-- | 'scanr1' is a variant of 'scanr' that has no starting value argument.
+scanr1 :: (Char -> Char -> Char) -> ByteString -> ByteString
+scanr1 f = B.scanr1 (\a b -> c2w (f (w2c a) (w2c b)))
+
-- | /O(n)/ 'replicate' @n x@ is a ByteString of length @n@ with @x@
-- the value of every element. The following holds:
--
-- | 'dropWhile' @p xs@ returns the suffix remaining after 'takeWhile' @p xs@.
dropWhile :: (Char -> Bool) -> ByteString -> ByteString
dropWhile f = B.dropWhile (f . w2c)
-{-# INLINE dropWhile #-}
+#if defined(__GLASGOW_HASKELL__)
+{-# INLINE [1] dropWhile #-}
+#endif
-- | 'break' @p@ is equivalent to @'span' ('not' . p)@.
break :: (Char -> Bool) -> ByteString -> (ByteString, ByteString)
break f = B.break (f . w2c)
-{-# INLINE break #-}
+#if defined(__GLASGOW_HASKELL__)
+{-# INLINE [1] break #-}
+#endif
-- | 'span' @p xs@ breaks the ByteString into two segments. It is
-- equivalent to @('takeWhile' p xs, 'dropWhile' p xs)@
breakEnd f = B.breakEnd (f . w2c)
{-# INLINE breakEnd #-}
+{-
-- | 'breakChar' breaks its ByteString argument at the first occurence
-- of the specified Char. It is more efficient than 'break' as it is
-- implemented with @memchr(3)@. I.e.
spanChar :: Char -> ByteString -> (ByteString, ByteString)
spanChar = B.spanByte . c2w
{-# INLINE spanChar #-}
+-}
-- | /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 'a' "aXaXaXa" == ["","X","X","X",""]
-- > split 'x' "x" == ["",""]
--
-- and
{-# INLINE splitWith #-}
-- the inline makes a big difference here.
+{-
-- | Like 'splitWith', except that sequences of adjacent separators are
-- treated as a single separator. eg.
--
tokens :: (Char -> Bool) -> ByteString -> [ByteString]
tokens f = B.tokens (f . w2c)
{-# INLINE tokens #-}
+-}
-- | The 'groupBy' function is the non-overloaded version of 'group'.
groupBy :: (Char -> Char -> Bool) -> ByteString -> [ByteString]
groupBy k = B.groupBy (\a b -> k (w2c a) (w2c b))
+{-
-- | /O(n)/ joinWithChar. An efficient way to join to two ByteStrings with a
-- char. Around 4 times faster than the generalised join.
--
joinWithChar :: Char -> ByteString -> ByteString -> ByteString
joinWithChar = B.joinWithByte . c2w
{-# INLINE joinWithChar #-}
+-}
-- | /O(1)/ 'ByteString' index (subscript) operator, starting from 0.
index :: ByteString -> Int -> Char
find f ps = w2c `fmap` B.find (f . w2c) ps
{-# INLINE find #-}
+{-
-- | /O(n)/ A first order equivalent of /filter . (==)/, for the common
-- case of filtering a single Char. It is more efficient to use
-- filterChar in this case.
filterNotChar :: Char -> ByteString -> ByteString
filterNotChar c = B.filterNotByte (c2w c)
{-# INLINE filterNotChar #-}
+-}
-- | /O(n)/ 'zip' takes two ByteStrings and returns a list of
-- corresponding pairs of Chars. If one input ByteString is short,
unsafeHead = w2c . B.unsafeHead
{-# INLINE unsafeHead #-}
--- | Unsafe 'ByteString' index (subscript) operator, starting from 0, returning a Char.
--- This omits the bounds check, which means there is an accompanying
--- obligation on the programmer to ensure the bounds are checked in some
--- other way.
-unsafeIndex :: ByteString -> Int -> Char
-unsafeIndex = (w2c .) . B.unsafeIndex
-{-# INLINE unsafeIndex #-}
-
-- ---------------------------------------------------------------------
-- Things that depend on the encoding
+{-# RULES
+ "FPS specialise break -> breakSpace"
+ break isSpace = breakSpace
+ #-}
+
-- | 'breakSpace' returns the pair of ByteStrings when the argument is
-- broken at the first whitespace byte. I.e.
--
| otherwise = do w <- peekByteOff ptr n
if (not . isSpaceWord8) w then firstspace ptr (n+1) m else return n
+{-# RULES
+ "FPS specialise dropWhile isSpace -> dropSpace"
+ dropWhile isSpace = dropSpace
+ #-}
+
-- | 'dropSpace' efficiently returns the 'ByteString' argument with
-- white space Chars removed from the front. It is more efficient than
-- calling dropWhile for removing whitespace. I.e.
| otherwise = do w <- peekElemOff ptr n
if isSpaceWord8 w then firstnonspace ptr (n+1) m else return n
+{-
-- | 'dropSpaceEnd' efficiently returns the 'ByteString' argument with
-- white space removed from the end. I.e.
--
| n < 0 = return n
| otherwise = do w <- peekElemOff ptr n
if isSpaceWord8 w then lastnonspace ptr (n-1) else return n
+-}
-- | 'lines' breaks a ByteString up into a list of ByteStrings at
-- newline Chars. The resulting strings do not contain newlines.
where search = elemIndex '\n'
{-# INLINE lines #-}
-{-# Bogus rule, wrong if there's not \n at end of line
-
-"length.lines/count"
- P.length . lines = count '\n'
-
- #-}
-
{-
-- Just as fast, but more complex. Should be much faster, I thought.
lines :: ByteString -> [ByteString]
-- > tokens isSpace = words
--
words :: ByteString -> [ByteString]
-words = B.tokens isSpaceWord8
+words = P.filter (not . B.null) . B.splitWith isSpaceWord8
{-# INLINE words #-}
-- | The 'unwords' function is analogous to the 'unlines' function, on words.
unwords = join (singleton ' ')
{-# INLINE unwords #-}
--- | /O(n)/ Indicies of newlines. Shorthand for
---
--- > elemIndices '\n'
---
-lineIndices :: ByteString -> [Int]
-lineIndices = elemIndices '\n'
-{-# INLINE lineIndices #-}
-
--- | 'lines\'' behaves like 'lines', in that it breaks a ByteString on
--- newline Chars. However, unlike the Prelude functions, 'lines\'' and
--- 'unlines\'' correctly reconstruct lines that are missing terminating
--- newlines characters. I.e.
---
--- > unlines (lines "a\nb\nc") == "a\nb\nc\n"
--- > unlines' (lines' "a\nb\nc") == "a\nb\nc"
---
--- Note that this means:
---
--- > lines "a\nb\nc\n" == ["a","b","c"]
--- > lines' "a\nb\nc\n" == ["a","b","c",""]
---
-lines' :: ByteString -> [ByteString]
-lines' ps = ps `seq` case elemIndex '\n' ps of
- Nothing -> [ps]
- Just n -> take n ps : lines' (drop (n+1) ps)
-
--- | 'linesCRLF\'' behaves like 'lines\'', but breaks on (\\cr?\\lf)
-linesCRLF' :: ByteString -> [ByteString]
-linesCRLF' ps = ps `seq` case elemIndex '\n' ps of
- Nothing -> [ps]
- Just 0 -> empty : linesCRLF' (drop 1 ps)
- Just n -> let k = if ps `unsafeIndex` (n-1) == '\r' then n-1 else n
- in take k ps : linesCRLF' (drop (n+1) ps)
-
--- | 'unlines\'' behaves like 'unlines', except that it also correctly
--- retores lines that do not have terminating newlines (see the
--- description for 'lines\'').
---
-unlines' :: [ByteString] -> ByteString
-unlines' ss = concat $ intersperse_newlines ss
- where intersperse_newlines (a:b:s) = a:newline: intersperse_newlines (b:s)
- intersperse_newlines s = s
- newline = singleton '\n'
-
--- | 'unlines\'' behaves like 'unlines', except that it also correctly
--- retores lines that do not have terminating newlines (see the
--- description for 'lines\''). Uses CRLF instead of LF.
---
-unlinesCRLF' :: [ByteString] -> ByteString
-unlinesCRLF' ss = concat $ intersperse_newlines ss
- where intersperse_newlines (a:b:s) = a:newline: intersperse_newlines (b:s)
- intersperse_newlines s = s
- newline = pack "\r\n"
-
--- | 'words\'' behaves like 'words', with the exception that it produces
--- output on ByteStrings with trailing whitespace that can be
--- correctly inverted by 'unwords'. I.e.
---
--- > words "a b c " == ["a","b","c"]
--- > words' "a b c " == ["a","b","c",""]
---
--- > unwords $ words "a b c " == "a b c"
--- > unwords $ words' "a b c " == "a b c "
---
-words' :: ByteString -> [ByteString]
-words' = B.splitWith isSpaceWord8
-
--- | 'unwords\'' behaves like 'unwords'. It is provided for consistency
--- with the other invertable words and lines functions.
-unwords' :: [ByteString] -> ByteString
-unwords' = unwords
-
--- | 'betweenLines' returns the ByteString between the two lines given,
--- or Nothing if they do not appear. The returned string is the first
--- and shortest string such that the line before it is the given first
--- line, and the line after it is the given second line.
-betweenLines :: ByteString -- ^ First line to look for
- -> ByteString -- ^ Second line to look for
- -> ByteString -- ^ 'ByteString' to look in
- -> Maybe (ByteString)
-
-betweenLines start end ps =
- case P.break (start ==) (lines ps) of
- (_, _:rest@(PS ps1 s1 _:_)) ->
- case P.break (end ==) rest of
- (_, PS _ s2 _:_) -> Just $ PS ps1 s1 (s2 - s1)
- _ -> Nothing
- _ -> Nothing
-
-- ---------------------------------------------------------------------
-- Reading from ByteStrings
end True _ n ps = Just (negate n, ps)
end _ _ n ps = Just (n, ps)
--- | /O(n)/ Like 'map', but not fuseable. The benefit is that it is
--- slightly faster for one-shot cases.
-map' :: (Char -> Char) -> ByteString -> ByteString
-map' f = B.map' (c2w . f . w2c)
+-- | readInteger reads an Integer from the beginning of the ByteString. If
+-- there is no integer at the beginning of the string, it returns Nothing,
+-- otherwise it just returns the int read, and the rest of the string.
+readInteger :: ByteString -> Maybe (Integer, ByteString)
+readInteger as
+ | null as = Nothing
+ | otherwise =
+ case unsafeHead as of
+ '-' -> first (unsafeTail as) >>= \(n, bs) -> return (-n, bs)
+ '+' -> first (unsafeTail as)
+ _ -> first as
+
+ where first ps | null ps = Nothing
+ | otherwise =
+ case B.unsafeHead ps of
+ w | w >= 0x30 && w <= 0x39 -> Just $
+ loop 1 (fromIntegral w - 0x30) [] (unsafeTail ps)
+ | otherwise -> Nothing
+
+ loop :: Int -> Int -> [Integer]
+ -> ByteString -> (Integer, ByteString)
+ STRICT4(loop)
+ loop d acc ns ps
+ | null ps = combine d acc ns empty
+ | otherwise =
+ case B.unsafeHead ps of
+ w | w >= 0x30 && w <= 0x39 ->
+ if d == 9 then loop 1 (fromIntegral w - 0x30)
+ (toInteger acc : ns)
+ (unsafeTail ps)
+ else loop (d+1)
+ (10*acc + (fromIntegral w - 0x30))
+ ns (unsafeTail ps)
+ | otherwise -> combine d acc ns ps
+
+ combine _ acc [] ps = (toInteger acc, ps)
+ combine d acc ns ps =
+ ((10^d * combine1 1000000000 ns + toInteger acc), ps)
+
+ combine1 _ [n] = n
+ combine1 b ns = combine1 (b*b) $ combine2 b ns
+
+ combine2 b (n:m:ns) = let t = m*b + n in t `seq` (t : combine2 b ns)
+ combine2 _ ns = ns
+
+-- | 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.
+readFile :: FilePath -> IO ByteString
+readFile f = bracket (openFile f ReadMode) hClose
+ (\h -> hFileSize h >>= hGet h . fromIntegral)
+
+-- | Write a 'ByteString' to a file.
+writeFile :: FilePath -> ByteString -> IO ()
+writeFile f txt = bracket (openFile f WriteMode) hClose
+ (\h -> hPut h txt)
+
+-- | Append a 'ByteString' to a file.
+appendFile :: FilePath -> ByteString -> IO ()
+appendFile f txt = bracket (openFile f AppendMode) hClose
+ (\h -> hPut h txt)
--- | /O(n)/ 'filter\'' is a non-fuseable version of filter, that may be
--- around 2x faster for some one-shot applications.
-filter' :: (Char -> Bool) -> ByteString -> ByteString
-filter' f = B.filter' (f . w2c)
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