Codec.CBOR.Magic

An internal module for doing magical, low-level, and unholy things in the name of efficiency.

Word utilities

grabWord8 :: Ptr () -> Word8

Grab a 8-bit Word given a Ptr to some address.

grabWord16 :: Ptr () -> Word16

Grab a 16-bit Word given a Ptr to some address.

grabWord32 :: Ptr () -> Word32

Grab a 32-bit Word given a Ptr to some address.

grabWord64 :: Ptr () -> Word64

Grab a 64-bit Word64 given a Ptr to some address.

ByteString utilities

eatTailWord8 :: ByteString -> Word8

Take the tail of a ByteString (i.e. drop the first byte) and read the resulting byte(s) as an 8-bit word value. The input ByteString MUST be at least 2 bytes long: one byte to drop from the front, and one to read as a Word value. This is not checked, and failure to ensure this will result in undefined behavior.

eatTailWord16 :: ByteString -> Word16

Take the tail of a ByteString (i.e. drop the first byte) and read the resulting byte(s) as a 16-bit word value. The input ByteString MUST be at least 3 bytes long: one byte to drop from the front, and two to read as a 16-bit Word value. This is not checked, and failure to ensure this will result in undefined behavior.

eatTailWord32 :: ByteString -> Word32

Take the tail of a ByteString (i.e. drop the first byte) and read the resulting byte(s) as a 32-bit word value. The input ByteString MUST be at least 5 bytes long: one byte to drop from the front, and four to read as a 32-bit Word value. This is not checked, and failure to ensure this will result in undefined behavior.

eatTailWord64 :: ByteString -> Word64

Take the tail of a ByteString (i.e. drop the first byte) and read the resulting byte(s) as a 64-bit word value. The input ByteString MUST be at least 9 bytes long: one byte to drop from the front, and eight to read as a 64-bit Word64 value. This is not checked, and failure to ensure this will result in undefined behavior.

Half-floats

wordToFloat16 :: Word16 -> Float

Convert a Word16 to a half-sized Float.

floatToWord16 :: Float -> Word16

Convert a half-sized Float to a Word.

Float/Word conversion

wordToFloat32 :: Word32 -> Float

Cast a Word32 to a Float.

wordToFloat64 :: Word64 -> Double

Cast a Word64 to a Float.

Int and Word explicit conversions

word8ToWord :: Word8 -> Word

word16ToWord :: Word16 -> Word

word32ToWord :: Word32 -> Word

word64ToWord :: Word64 -> Word

word8ToInt :: Word8 -> Int

word16ToInt :: Word16 -> Int

word32ToInt :: Word32 -> Int

word64ToInt :: Word64 -> Maybe Int

intToWord :: Int -> Word

intToInt64 :: Int -> Int64

intToWord64 :: Int -> Word64

int64ToWord64 :: Int64 -> Word64

Integer utilities

nintegerFromBytes :: ByteString -> Integer

Create a negative Integer out of a raw ByteString.

uintegerFromBytes :: ByteString -> Integer

Create an Integer out of a raw ByteString.

Simple mutable counters

data Counter s

An efficient, mutable counter. Designed to be used inside ST or other primitive monads, hence it carries an abstract rank-2 s type parameter.

newCounter :: Int -> ST s (Counter s)

Create a new counter with a starting Int value.

readCounter :: Counter s -> ST s Int

Read the current value of a Counter.

writeCounter :: Counter s -> Int -> ST s ()

Write a new value into the Counter.

incCounter :: Counter s -> ST s ()

Increment a Counter by one.

decCounter :: Counter s -> ST s ()

Decrement a Counter by one.

Array support

copyByteStringToByteArray :: ByteString -> ByteArray

Copy a ByteString and create a primitive ByteArray from it.

copyByteArrayToByteString

Arguments

:: ByteArray

ByteArray to copy from.

-> Int

Offset into the ByteArray to start with.

-> Int

Length of the data to copy.

-> ByteString

Copy a ByteArray at a certain offset and length into a ByteString.