Data.ByteString.Short.Internal

Copyright (c) Duncan Coutts 2012-2013
License BSD-style
Maintainer [email protected]
Stability stable
Portability ghc only
Safe Haskell Unsafe
Language Haskell98

Description

Internal representation of ShortByteString

The ShortByteString type and representation

data ShortByteString Source

A compact representation of a Word8 vector.

It has a lower memory overhead than a ByteString and and does not contribute to heap fragmentation. It can be converted to or from a ByteString (at the cost of copying the string data). It supports very few other operations.

It is suitable for use as an internal representation for code that needs to keep many short strings in memory, but it should not be used as an interchange type. That is, it should not generally be used in public APIs. The ByteString type is usually more suitable for use in interfaces; it is more flexible and it supports a wide range of operations.

Constructors

SBS ByteArray#
Instances
Instances details
Eq ShortByteString
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Defined in Data.ByteString.Short.Internal

Data ShortByteString
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Defined in Data.ByteString.Short.Internal

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> ShortByteString -> c ShortByteString Source

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c ShortByteString Source

toConstr :: ShortByteString -> Constr Source

dataTypeOf :: ShortByteString -> DataType Source

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c ShortByteString) Source

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c ShortByteString) Source

gmapT :: (forall b. Data b => b -> b) -> ShortByteString -> ShortByteString Source

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> ShortByteString -> r Source

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> ShortByteString -> r Source

gmapQ :: (forall d. Data d => d -> u) -> ShortByteString -> [u] Source

gmapQi :: Int -> (forall d. Data d => d -> u) -> ShortByteString -> u Source

gmapM :: Monad m => (forall d. Data d => d -> m d) -> ShortByteString -> m ShortByteString Source

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> ShortByteString -> m ShortByteString Source

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> ShortByteString -> m ShortByteString Source

Ord ShortByteString
Instance details

Defined in Data.ByteString.Short.Internal

Read ShortByteString
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Defined in Data.ByteString.Short.Internal

Show ShortByteString
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Defined in Data.ByteString.Short.Internal

IsString ShortByteString
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Defined in Data.ByteString.Short.Internal

Semigroup ShortByteString
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Defined in Data.ByteString.Short.Internal

Monoid ShortByteString
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Defined in Data.ByteString.Short.Internal

NFData ShortByteString
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Defined in Data.ByteString.Short.Internal

Methods

rnf :: ShortByteString -> () Source

Conversions

toShort :: ByteString -> ShortByteString Source

O(n). Convert a ByteString into a ShortByteString.

This makes a copy, so does not retain the input string.

fromShort :: ShortByteString -> ByteString Source

O(n). Convert a ShortByteString into a ByteString.

pack :: [Word8] -> ShortByteString Source

O(n). Convert a list into a ShortByteString

unpack :: ShortByteString -> [Word8] Source

O(n). Convert a ShortByteString into a list.

Other operations

empty :: ShortByteString Source

O(1). The empty ShortByteString.

null :: ShortByteString -> Bool Source

O(1) Test whether a ShortByteString is empty.

length :: ShortByteString -> Int Source

O(1) The length of a ShortByteString.

index :: ShortByteString -> Int -> Word8 Source

O(1) ShortByteString index (subscript) operator, starting from 0.

unsafeIndex :: ShortByteString -> Int -> Word8 Source

Low level operations

createFromPtr Source

Arguments

:: Ptr a

source data

-> Int

number of bytes to copy

-> IO ShortByteString

copyToPtr Source

Arguments

:: ShortByteString

source data

-> Int

offset into source

-> Ptr a

destination

-> Int

number of bytes to copy

-> IO ()

Low level conversions

Packing CStrings and pointers

packCString :: CString -> IO ShortByteString Source

O(n). Construct a new ShortByteString from a CString. The resulting ShortByteString is an immutable copy of the original CString, and is managed on the Haskell heap. The original CString must be null terminated.

Since: bytestring-0.10.10.0

packCStringLen :: CStringLen -> IO ShortByteString Source

O(n). Construct a new ShortByteString from a CStringLen. The resulting ShortByteString is an immutable copy of the original CStringLen. The ShortByteString is a normal Haskell value and will be managed on the Haskell heap.

Since: bytestring-0.10.10.0

Using ByteStrings as CStrings

useAsCString :: ShortByteString -> (CString -> IO a) -> IO a Source

O(n) construction. Use a ShortByteString with a function requiring a null-terminated CString. The CString is a copy and will be freed automatically; it must not be stored or used after the subcomputation finishes.

Since: bytestring-0.10.10.0

useAsCStringLen :: ShortByteString -> (CStringLen -> IO a) -> IO a Source

O(n) construction. Use a ShortByteString with a function requiring a CStringLen. As for useAsCString this function makes a copy of the original ShortByteString. It must not be stored or used after the subcomputation finishes.

Since: bytestring-0.10.10.0

© The University of Glasgow and others
Licensed under a BSD-style license (see top of the page).
https://downloads.haskell.org/~ghc/8.10.2/docs/html/libraries/bytestring-0.10.10.0/Data-ByteString-Short-Internal.html