| binary-strict-0.2: Binary deserialisation using strict ByteStrings | Contents | Index |
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Data.Binary.Strict.IncrementalGet | Portability | portable to Hugs and GHC. | Stability | experimental | Maintainer | Adam Langley <agl@imperialviolet.org> |
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Description |
This is a version of the Get monad for incremental parsing. The parser is
written as if a single, huge, strict ByteString was to be parsed. It
produces results as it parses by calling yield.
However, if the parser runs out of data, rather than failing the caller sees
a Partial result, which includes the list of yielded values so far and a
continuation. By calling the continuation with more data, the parser
continues, none the wiser.
Take the following example
testParse = do
getWord16be >>= yield
testParse
test = runGet testParse $ B.pack [1,0,0]
Here, testParse never completes, but yields Word16 values forever. It's
started with a 3 byte ByteString and will yield a single value before
running out of data. Thus, test = Partial cont [256]. Calling cont
with a single extra byte will yield another Word16 value etc.
The lookahead functions have been removed from this parser because of their
incompatibility with the incremental monad at the moment.
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Synopsis |
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The Get type
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data Get r a |
Instances | |
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data Result a |
The result of a partial parse
| Constructors | Failed String | the parse failed with the given error message
| Finished ByteString [a] | the parse finished and produced the given list of
results doing so. Any unparsed data is returned.
| Partial (ByteString -> Result a) [a] | the parse ran out of data before finishing, but produced
the given list of results before doing so. To continue the
parse pass more data to the given continuation
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| Instances | |
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runGet :: Get r a -> ByteString -> Result r |
Start a parser and return the first Result.
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Utility
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skip :: Int -> Get r () |
Skip ahead n bytes. Fails if fewer than n bytes are available.
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yield :: r -> Get r () |
Return a value from the parse
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bytesRead :: Get r Int |
Get the total number of bytes read to this point.
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remaining :: Get r Int |
Get the number of remaining unparsed bytes.
Useful for checking whether all input has been consumed.
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isEmpty :: Get r Bool |
Test whether all input has been consumed,
i.e. there are no remaining unparsed bytes.
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Parsing particular types
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getWord8 :: Get r Word8 |
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ByteStrings
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getByteString :: Int -> Get r ByteString |
An efficient get method for strict ByteStrings. Fails if fewer
than n bytes are left in the input.
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Big-endian reads
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getWord16be :: Get r Word16 |
Read a Word16 in big endian format
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getWord32be :: Get r Word32 |
Read a Word32 in big endian format
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getWord64be :: Get r Word64 |
Read a Word64 in big endian format
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Little-endian reads
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getWord16le :: Get r Word16 |
Read a Word16 in little endian format
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getWord32le :: Get r Word32 |
Read a Word32 in little endian format
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getWord64le :: Get r Word64 |
Read a Word64 in little endian format
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Host-endian, unaligned reads
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getWordhost :: Get r 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.
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getWord16host :: Get r Word16 |
O(1). Read a 2 byte Word16 in native host order and host endianness.
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getWord32host :: Get r Word32 |
O(1). Read a Word32 in native host order and host endianness.
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getWord64host :: Get r Word64 |
O(1). Read a Word64 in native host order and host endianess.
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Produced by Haddock version 0.8 |