Data.Binary.Strict.BitGet

This is a reader monad for parsing bit-aligned data. The usual Get monad handles byte aligned data well.

In this monad, the current offset into the input is a number of bits, and fetching n bits from the current position will shift everything correctly. Bit vectors are represented as ByteStrings here either the first n bits are valid (left aligned) or the last n bits are (right aligned).

If one is looking to parse integers etc, right alignment is the easist to work with, however left alignment makes more sense in some situations.

Get BitGet type

data BitGet a

Instances

Monad BitGet

Defined in Data.Binary.Strict.BitGet

Methods

(>>=) :: BitGet a -> (a -> BitGet b) -> BitGet b

(>>) :: BitGet a -> BitGet b -> BitGet b

return :: a -> BitGet a

fail :: String -> BitGet a

Functor BitGet

Defined in Data.Binary.Strict.BitGet

Methods

fmap :: (a -> b) -> BitGet a -> BitGet b

(<$) :: a -> BitGet b -> BitGet a

Applicative BitGet

Defined in Data.Binary.Strict.BitGet

Methods

pure :: a -> BitGet a

(<*>) :: BitGet (a -> b) -> BitGet a -> BitGet b

liftA2 :: (a -> b -> c) -> BitGet a -> BitGet b -> BitGet c

(*>) :: BitGet a -> BitGet b -> BitGet b

(<*) :: BitGet a -> BitGet b -> BitGet a

runBitGet :: ByteString -> BitGet a -> Either String a

Run a BitGet on a ByteString

Utility

skip :: Int -> BitGet ()

Skip n bits of the input. Fails if less then n bits remain

remaining :: BitGet Int

Return the number of bits remaining to be parsed

isEmpty :: BitGet Bool

Return true if there are no more bits to parse

lookAhead :: BitGet a -> BitGet a

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

Generic parsing

getBit :: BitGet Bool

Get a single bit from the input

getLeftByteString :: Int -> BitGet ByteString

Get a ByteString with the given number of bits, left aligned.

getRightByteString :: Int -> BitGet ByteString

Get a ByteString with the given number of bits in, right aligned.

Interpreting some number of bits as an unsigned integer

getAsWord8 :: Int -> BitGet Word8

getAsWord16 :: Int -> BitGet Word16

Read a Word16 in big endian format

getAsWord32 :: Int -> BitGet Word32

Read a Word32 in big endian format

getAsWord64 :: Int -> BitGet Word64

Read a Word64 in big endian format

Interpreting some number of bits as a signed integer

getAsInt8 :: Int -> BitGet Int8

Reads an Int8, sign-extending the input if it has fewer than 8 bits.

getAsInt16 :: Int -> BitGet Int16

Reads an Int16 in big endian format, sign-extending the input if it has fewer than 16 bits.

getAsInt32 :: Int -> BitGet Int32

Reads an Int32 in big endian format, sign-extending the input if it has fewer than 32 bits.

getAsInt64 :: Int -> BitGet Int64

Reads an Int64 in big endian format, sign-extending the input if it has fewer than 64 bits.

Parsing particular types

getWord8 :: BitGet Word8

getWord16le :: BitGet Word16

getWord16be :: BitGet Word16

getWord16host :: BitGet Word16

getWord32le :: BitGet Word32

getWord32be :: BitGet Word32

getWord32host :: BitGet Word32

getWord64le :: BitGet Word64

getWord64be :: BitGet Word64

getWord64host :: BitGet Word64

getWordhost :: BitGet Word