Data.Serialize.Get

cereal-0.3.0.0: A binary serialization library

Stability | Portability :
Maintainer | Trevor Elliott <trevor@galois.com>

Data.Serialize.Get

Contents

- The Get type
- Parsing
- Utility
- Parsing particular types
  - ByteStrings
  - Big-endian reads
  - Little-endian reads
  - Host-endian, unaligned reads
  - Containers

Description

The Get monad. A monad for efficiently building structures from strict ByteStrings

Synopsis

- data Get a
- runGet :: Get a -> ByteString -> Either String a
- runGetState :: Get a -> ByteString -> Int -> Either String (a, ByteString)
- isolate :: Int -> Get a -> Get a
- label :: String -> Get a -> Get a
- skip :: Int -> Get ()
- uncheckedSkip :: Int -> Get ()
- lookAhead :: Get a -> Get a
- lookAheadM :: Get (Maybe a) -> Get (Maybe a)
- lookAheadE :: Get (Either a b) -> Get (Either a b)
- uncheckedLookAhead :: Int -> Get ByteString
- getBytes :: Int -> Get ByteString
- remaining :: Get Int
- isEmpty :: Get Bool
- getWord8 :: Get Word8
- getByteString :: Int -> Get ByteString
- getLazyByteString :: Int64 -> Get ByteString
- getWord16be :: Get Word16
- getWord32be :: Get Word32
- getWord64be :: Get Word64
- getWord16le :: Get Word16
- getWord32le :: Get Word32
- getWord64le :: Get Word64
- getWordhost :: Get Word
- getWord16host :: Get Word16
- getWord32host :: Get Word32
- getWord64host :: Get Word64
- getTwoOf :: Get a -> Get b -> Get (a, b)
- getListOf :: Get a -> Get [a]
- getIArrayOf :: (Ix i, IArray a e) => Get i -> Get e -> Get (a i e)
- getTreeOf :: Get a -> Get (Tree a)
- getSeqOf :: Get a -> Get (Seq a)
- getMapOf :: Ord k => Get k -> Get a -> Get (Map k a)
- getIntMapOf :: Get Int -> Get a -> Get (IntMap a)
- getSetOf :: Ord a => Get a -> Get (Set a)
- getIntSetOf :: Get Int -> Get IntSet
- getMaybeOf :: Get a -> Get (Maybe a)
- getEitherOf :: Get a -> Get b -> Get (Either a b)

# The Get type

data Get a

The Get monad is an Exception and State monad.

Instances

Monad Get |
Functor Get |
MonadPlus Get |
Applicative Get |
Alternative Get |

runGet :: Get a -> ByteString -> Either String a

Run the Get monad applies a `get`-based parser on the input ByteString

runGetState :: Get a -> ByteString -> Int -> Either String (a, ByteString)

Run the Get monad applies a `get`-based parser on the input ByteString. Additional to the result of get it returns the number of consumed bytes and the rest of the input.

# Parsing

isolate :: Int -> Get a -> Get a

Isolate an action to operating within a fixed block of bytes. The action is required to consume all the bytes that it is isolated to.

label :: String -> Get a -> Get a

skip :: Int -> Get ()

Skip ahead `n` bytes. Fails if fewer than `n` bytes are available.

uncheckedSkip :: Int -> Get ()

Skip ahead `n` bytes. No error if there isn't enough bytes.

lookAhead :: Get a -> Get a

Run `ga`, but return without consuming its input. Fails if `ga` fails.

lookAheadM :: Get (Maybe a) -> Get (Maybe a)

Like `lookAhead`, but consume the input if `gma` returns 'Just _'. Fails if `gma` fails.

lookAheadE :: Get (Either a b) -> Get (Either a b)

Like `lookAhead`, but consume the input if `gea` returns 'Right _'. Fails if `gea` fails.

uncheckedLookAhead :: Int -> Get ByteString

Get the next up to `n` bytes as a ByteString, without consuming them.

# Utility

getBytes :: Int -> Get ByteString

Pull `n` bytes from the input, as a strict ByteString.

remaining :: Get Int

Get the number of remaining unparsed bytes. Useful for checking whether all input has been consumed. Note that this forces the rest of the input.

isEmpty :: Get Bool

Test whether all input has been consumed, i.e. there are no remaining unparsed bytes.

# Parsing particular types

getWord8 :: Get Word8

Read a Word8 from the monad state

## ByteStrings

getByteString :: Int -> Get ByteString

An efficient `get` method for strict ByteStrings. Fails if fewer than `n` bytes are left in the input. This function creates a fresh copy of the underlying bytes.

getLazyByteString :: Int64 -> Get ByteString

## Big-endian reads

getWord16be :: Get Word16

Read a Word16 in big endian format

getWord32be :: Get Word32

Read a Word32 in big endian format

getWord64be :: Get Word64

Read a Word64 in big endian format

## Little-endian reads

getWord16le :: Get Word16

Read a Word16 in little endian format

getWord32le :: Get Word32

Read a Word32 in little endian format

getWord64le :: Get Word64

Read a Word64 in little endian format

## Host-endian, unaligned reads

getWordhost :: Get Word

O(1). Read a single native machine word. The word is read in host order, host endian form, for the machine you're on. On a 64 bit machine the Word is an 8 byte value, on a 32 bit machine, 4 bytes.

getWord16host :: Get Word16

O(1). Read a 2 byte Word16 in native host order and host endianness.

getWord32host :: Get Word32

O(1). Read a Word32 in native host order and host endianness.

getWord64host :: Get Word64

O(1). Read a Word64 in native host order and host endianess.

## Containers

getTwoOf :: Get a -> Get b -> Get (a, b)

getListOf :: Get a -> Get [a]

Get a list in the following format: Word64 (big endian format) element 1 ... element n

getIArrayOf :: (Ix i, IArray a e) => Get i -> Get e -> Get (a i e)

Get an IArray in the following format: index (lower bound) index (upper bound) Word64 (big endian format) element 1 ... element n

getTreeOf :: Get a -> Get (Tree a)

Read as a list of lists.

getSeqOf :: Get a -> Get (Seq a)

Get a sequence in the following format: Word64 (big endian format) element 1 ... element n

getMapOf :: Ord k => Get k -> Get a -> Get (Map k a)

Read as a list of pairs of key and element.

getIntMapOf :: Get Int -> Get a -> Get (IntMap a)

Read as a list of pairs of int and element.

getSetOf :: Ord a => Get a -> Get (Set a)

Read as a list of elements.

getIntSetOf :: Get Int -> Get IntSet

Read as a list of ints.

getMaybeOf :: Get a -> Get (Maybe a)

Read in a Maybe in the following format: Word8 (0 for Nothing, anything else for Just) element (when Just)

getEitherOf :: Get a -> Get b -> Get (Either a b)

Read an Either, in the following format: Word8 (0 for Left, anything else for Right) element a when 0, element b otherwise