Modulebytestring-0.12.2.0Haskell2010

Data.ByteString.Lazy.Internal

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.

2 types
14 values

Packagebytestring-0.12.2.0
Exports16
LanguageHaskell2010
LicenceBSD-3-Clause
SourceInternal.hs

The lazy `ByteString` type and representation

5 declarations

datadata ByteString

A space-efficient representation of a Word8 vector, supporting many efficient operations.

A LazyByteString 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 !StrictByteString ByteString

Instances12IsList, Eq, Data, Ord, Read, Show, …

IsList ByteStringDefined in bytestring-0.12.2.0 · Data.ByteString.Lazy.Internal
Eq ByteStringDefined in bytestring-0.12.2.0 · Data.ByteString.Lazy.Internal
Data ByteStringDefined in bytestring-0.12.2.0 · Data.ByteString.Lazy.Internal
Ord ByteStringDefined in bytestring-0.12.2.0 · Data.ByteString.Lazy.Internal
Read ByteStringDefined in bytestring-0.12.2.0 · Data.ByteString.Lazy.Internal
Show ByteStringDefined in bytestring-0.12.2.0 · Data.ByteString.Lazy.Internal
IsString ByteStringDefined in bytestring-0.12.2.0 · Data.ByteString.Lazy.Internal
Beware: fromString truncates multi-byte characters to octets. e.g. "枯朶に烏のとまりけり秋の暮" becomes �6k�nh~�Q��n�
Semigroup ByteStringDefined in bytestring-0.12.2.0 · Data.ByteString.Lazy.Internal
Monoid ByteStringDefined in bytestring-0.12.2.0 · Data.ByteString.Lazy.Internal
NFData ByteStringDefined in bytestring-0.12.2.0 · Data.ByteString.Lazy.Internal
Lift ByteStringDefined in bytestring-0.12.2.0 · Data.ByteString.Lazy.Internal
type Item ByteString = Word8Defined in bytestring-0.12.2.0 · Data.ByteString.Lazy.Internal

typetype LazyByteString = ByteString

Type synonym for the lazy flavour of ByteString.

valuechunk :: StrictByteString -> ByteString -> ByteString

Smart constructor for Chunk. Guarantees the data type invariant.

valuefoldrChunks :: (StrictByteString -> a -> a) -> a -> ByteString -> a

Consume the chunks of a lazy ByteString with a natural right fold.

valuefoldlChunks :: (a -> StrictByteString -> a) -> a -> ByteString -> a

Consume the chunks of a lazy ByteString with a strict, tail-recursive, accumulating left fold.

Data type invariant and abstraction function

2 declarations

valueinvariant :: ByteString -> Bool

The data type invariant: Every ByteString is either Empty or consists of non-null StrictByteStrings. All functions must preserve this.

valuecheckInvariant :: ByteString -> ByteString

Lazily checks that the given ByteString satisfies the data type's "no empty chunks" invariant, raising an exception in place of the first chunk that does not satisfy the invariant.

Chunk allocation sizes

3 declarations

valuedefaultChunkSize :: Int

The chunk size used for I/O. Currently set to 32k, less the memory management overhead

valuesmallChunkSize :: Int

The recommended chunk size. Currently set to 4k, less the memory management overhead

valuechunkOverhead :: Int

The memory management overhead. Currently this is tuned for GHC only.

Conversion with lists: packing and unpacking

4 declarations

valuepackBytes :: [Word8] -> ByteString

valuepackChars :: [Char] -> ByteString

valueunpackBytes :: ByteString -> [Word8]

valueunpackChars :: ByteString -> [Char]

Conversions with strict ByteString

2 declarations

valuefromStrict :: StrictByteString -> LazyByteString

O(1) Convert a StrictByteString into a LazyByteString.

valuetoStrict :: LazyByteString -> StrictByteString

O(n) Convert a LazyByteString into a StrictByteString.

Note that this is an expensive operation that forces the whole LazyByteString into memory and then copies all the data. If possible, try to avoid converting back and forth between strict and lazy bytestrings.