| Copyright | (c) Don Stewart 2006-2008 (c) Duncan Coutts 2006-2011 |
|---|---|
| License | BSD-style |
| Maintainer | dons00@gmail.com, duncan@community.haskell.org |
| Stability | unstable |
| Portability | non-portable |
| Safe Haskell | Unsafe |
| Language | Haskell2010 |
Data.ByteString.Lazy.Internal
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
- chunk :: ByteString -> ByteString -> ByteString
- foldrChunks :: (ByteString -> a -> a) -> a -> ByteString -> a
- foldlChunks :: (a -> ByteString -> a) -> a -> ByteString -> a
- invariant :: ByteString -> Bool
- checkInvariant :: ByteString -> ByteString
- defaultChunkSize :: Int
- smallChunkSize :: Int
- chunkOverhead :: Int
- packBytes :: [Word8] -> ByteString
- packChars :: [Char] -> ByteString
- unpackBytes :: ByteString -> [Word8]
- unpackChars :: ByteString -> [Char]
- fromStrict :: ByteString -> ByteString
- toStrict :: ByteString -> ByteString
The lazy ByteString type and representation
data ByteString Source #
A space-efficient representation of a Word8 vector, supporting many
efficient operations.
A lazy ByteString contains 8-bit bytes, or by using the operations
from Data.ByteString.Lazy.Char8 it can be interpreted as containing
8-bit characters.
Constructors
| Empty | |
| Chunk !ByteString ByteString |
Instances
chunk :: ByteString -> ByteString -> ByteString Source #
Smart constructor for Chunk. Guarantees the data type invariant.
foldrChunks :: (ByteString -> a -> a) -> a -> ByteString -> a Source #
Consume the chunks of a lazy ByteString with a natural right fold.
foldlChunks :: (a -> ByteString -> a) -> a -> ByteString -> a Source #
Consume the chunks of a lazy ByteString with a strict, tail-recursive, accumulating left fold.
Data type invariant and abstraction function
invariant :: ByteString -> Bool Source #
The data type invariant:
Every ByteString is either Empty or consists of non-null ByteStrings.
All functions must preserve this, and the QC properties must check this.
checkInvariant :: ByteString -> ByteString Source #
In a form that checks the invariant lazily.
Chunk allocation sizes
defaultChunkSize :: Int Source #
The chunk size used for I/O. Currently set to 32k, less the memory management overhead
smallChunkSize :: Int Source #
The recommended chunk size. Currently set to 4k, less the memory management overhead
chunkOverhead :: Int Source #
The memory management overhead. Currently this is tuned for GHC only.
Conversion with lists: packing and unpacking
packBytes :: [Word8] -> ByteString Source #
packChars :: [Char] -> ByteString Source #
unpackBytes :: ByteString -> [Word8] Source #
unpackChars :: ByteString -> [Char] Source #
Conversions with strict ByteString
fromStrict :: ByteString -> ByteString Source #
O(1) Convert a strict ByteString into a lazy ByteString.
toStrict :: ByteString -> ByteString Source #
O(n) Convert a lazy ByteString into a strict ByteString.
Note that this is an expensive operation that forces the whole lazy ByteString into memory and then copies all the data. If possible, try to avoid converting back and forth between strict and lazy bytestrings.