Copyright	(c) Edward Kmett 2013
License	BSD3
Maintainer	Edward Kmett <ekmett@gmail.com>
Stability	experimental
Portability	type-families
Safe Haskell	Trustworthy
Language	Haskell98

Data.Bytes.Get

Description

This module generalizes the binary Get and cereal Get monads in an ad hoc fashion to permit code to be written that is compatible across them.

Moreover, this class permits code to be written to be portable over various monad transformers applied to these as base monads.

Synopsis

Documentation

class (Integral (Remaining m), Monad m, Applicative m) => MonadGet m where Source

Minimal complete definition

lookAhead, lookAheadM, lookAheadE

Associated Types

type Remaining m :: * Source

An Integral number type used for unchecked skips and counting.

type Bytes m :: * Source

The underlying ByteString type used by this instance

Methods

skip :: Int -> m () Source

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

ensure :: Int -> m ByteString Source

If at least n bytes are available return at least that much of the current input. Otherwise fail.

lookAhead :: m a -> m a Source

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

lookAheadM :: m (Maybe a) -> m (Maybe a) Source

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

lookAheadE :: m (Either a b) -> m (Either a b) Source

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

getBytes :: Int -> m ByteString Source

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

remaining :: m (Remaining m) Source

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 :: m Bool Source

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

getWord8 :: m Word8 Source

Read a Word8 from the monad state

getByteString :: Int -> m ByteString Source

An efficient get method for strict ByteStrings. Fails if fewer than n bytes are left in the input.

getLazyByteString :: Int64 -> m ByteString Source

An efficient get method for lazy ByteStrings. Does not fail if fewer than n bytes are left in the input.

getWord16be :: m Word16 Source

Read a Word16 in big endian format

getWord16le :: m Word16 Source

Read a Word16 in little endian format

getWord16host :: m Word16 Source

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

getWord32be :: m Word32 Source

Read a Word32 in big endian format

getWord32le :: m Word32 Source

Read a Word32 in little endian format

getWord32host :: m Word32 Source

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

getWord64be :: m Word64 Source

Read a Word64 in big endian format

getWord64le :: m Word64 Source

Read a Word64 in little endian format

getWord64host :: m Word64 Source

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

getWordhost :: m Word Source

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.

Instances

MonadGet Get
MonadGet Get
MonadGet m => MonadGet (ReaderT e m)
MonadGet m => MonadGet (StateT s m)
MonadGet m => MonadGet (StateT s m)
MonadGet m => MonadGet (ExceptT e m)
(MonadGet m, Monoid w) => MonadGet (WriterT w m)
(MonadGet m, Monoid w) => MonadGet (WriterT w m)
(MonadGet m, Monoid w) => MonadGet (RWST r w s m)
(MonadGet m, Monoid w) => MonadGet (RWST r w s m)

runGetL :: Get a -> ByteString -> a Source

Get something from a lazy ByteString using runGet.

runGetS :: Get a -> ByteString -> Either String a Source

Get something from a strict ByteString using runGet.