bytestring-0.9.1.4: Fast, packed, strict and lazy byte arrays with a list interfaceContentsIndex
Data.ByteString.Internal
Portabilityportable
Stabilityexperimental
MaintainerDon Stewart <dons@galois.com>
Contents
The ByteString type and representation
Low level introduction and elimination
Conversion to and from ForeignPtrs
Utilities
Standard C Functions
cbits functions
Internal GHC magic
Chars
Description
A module containing semi-public ByteString internals. This exposes the ByteString representation and low level construction functions. Modules which extend the ByteString system will need to use this module while ideally most users will be able to make do with the public interface modules.
Synopsis
data ByteString = PS !(ForeignPtr Word8) !Int !Int
create :: Int -> (Ptr Word8 -> IO ()) -> IO ByteString
createAndTrim :: Int -> (Ptr Word8 -> IO Int) -> IO ByteString
createAndTrim' :: Int -> (Ptr Word8 -> IO (Int, Int, a)) -> IO (ByteString, a)
unsafeCreate :: Int -> (Ptr Word8 -> IO ()) -> ByteString
mallocByteString :: Int -> IO (ForeignPtr a)
fromForeignPtr :: ForeignPtr Word8 -> Int -> Int -> ByteString
toForeignPtr :: ByteString -> (ForeignPtr Word8, Int, Int)
inlinePerformIO :: IO a -> a
nullForeignPtr :: ForeignPtr Word8
c_strlen :: CString -> IO CSize
c_free_finalizer :: FunPtr (Ptr Word8 -> IO ())
memchr :: Ptr Word8 -> Word8 -> CSize -> IO (Ptr Word8)
memcmp :: Ptr Word8 -> Ptr Word8 -> CSize -> IO CInt
memcpy :: Ptr Word8 -> Ptr Word8 -> CSize -> IO ()
memset :: Ptr Word8 -> Word8 -> CSize -> IO (Ptr Word8)
c_reverse :: Ptr Word8 -> Ptr Word8 -> CULong -> IO ()
c_intersperse :: Ptr Word8 -> Ptr Word8 -> CULong -> Word8 -> IO ()
c_maximum :: Ptr Word8 -> CULong -> IO Word8
c_minimum :: Ptr Word8 -> CULong -> IO Word8
c_count :: Ptr Word8 -> CULong -> Word8 -> IO CULong
memcpy_ptr_baoff :: Ptr a -> RawBuffer -> CInt -> CSize -> IO (Ptr ())
w2c :: Word8 -> Char
c2w :: Char -> Word8
isSpaceWord8 :: Word8 -> Bool
isSpaceChar8 :: Char -> Bool
The ByteString type and representation
data ByteString

A space-efficient representation of a Word8 vector, supporting many efficient operations. A ByteString contains 8-bit characters only.

Instances of Eq, Ord, Read, Show, Data, Typeable

Constructors
PS !(ForeignPtr Word8) !Int !Int
show/hide Instances
Low level introduction and elimination
create :: Int -> (Ptr Word8 -> IO ()) -> IO ByteString
Create ByteString of size l and use action f to fill it's contents.
createAndTrim :: Int -> (Ptr Word8 -> IO Int) -> IO ByteString

Given the maximum size needed and a function to make the contents of a ByteString, createAndTrim makes the ByteString. The generating function is required to return the actual final size (<= the maximum size), and the resulting byte array is realloced to this size.

createAndTrim is the main mechanism for creating custom, efficient ByteString functions, using Haskell or C functions to fill the space.

createAndTrim' :: Int -> (Ptr Word8 -> IO (Int, Int, a)) -> IO (ByteString, a)
unsafeCreate :: Int -> (Ptr Word8 -> IO ()) -> ByteString
A way of creating ByteStrings outside the IO monad. The Int argument gives the final size of the ByteString. Unlike createAndTrim the ByteString is not reallocated if the final size is less than the estimated size.
mallocByteString :: Int -> IO (ForeignPtr a)
Wrapper of mallocForeignPtrBytes with faster implementation for GHC 6.5 builds newer than 060606
Conversion to and from ForeignPtrs
fromForeignPtr
:: ForeignPtr Word8
-> IntOffset
-> IntLength
-> ByteString
O(1) Build a ByteString from a ForeignPtr
toForeignPtr
:: ByteString
-> (ForeignPtr Word8, Int, Int)(ptr, offset, length)
O(1) Deconstruct a ForeignPtr from a ByteString
Utilities
inlinePerformIO :: IO a -> a
Just like unsafePerformIO, but we inline it. Big performance gains as it exposes lots of things to further inlining. Very unsafe. In particular, you should do no memory allocation inside an inlinePerformIO block. On Hugs this is just unsafePerformIO.
nullForeignPtr :: ForeignPtr Word8
The 0 pointer. Used to indicate the empty Bytestring.
Standard C Functions
c_strlen :: CString -> IO CSize
c_free_finalizer :: FunPtr (Ptr Word8 -> IO ())
memchr :: Ptr Word8 -> Word8 -> CSize -> IO (Ptr Word8)
memcmp :: Ptr Word8 -> Ptr Word8 -> CSize -> IO CInt
memcpy :: Ptr Word8 -> Ptr Word8 -> CSize -> IO ()
memset :: Ptr Word8 -> Word8 -> CSize -> IO (Ptr Word8)
cbits functions
c_reverse :: Ptr Word8 -> Ptr Word8 -> CULong -> IO ()
c_intersperse :: Ptr Word8 -> Ptr Word8 -> CULong -> Word8 -> IO ()
c_maximum :: Ptr Word8 -> CULong -> IO Word8
c_minimum :: Ptr Word8 -> CULong -> IO Word8
c_count :: Ptr Word8 -> CULong -> Word8 -> IO CULong
Internal GHC magic
memcpy_ptr_baoff :: Ptr a -> RawBuffer -> CInt -> CSize -> IO (Ptr ())
Chars
w2c :: Word8 -> Char
Conversion between Word8 and Char. Should compile to a no-op.
c2w :: Char -> Word8
Unsafe conversion between Char and Word8. This is a no-op and silently truncates to 8 bits Chars > '\255'. It is provided as convenience for ByteString construction.
isSpaceWord8 :: Word8 -> Bool
Selects words corresponding to white-space characters in the Latin-1 range ordered by frequency.
isSpaceChar8 :: Char -> Bool
Selects white-space characters in the Latin-1 range
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