Data.UUID

This library is useful for comparing, parsing and printing Universally Unique Identifiers. See http://en.wikipedia.org/wiki/UUID for the general idea. See http://tools.ietf.org/html/rfc4122 for the specification.

• Random UUIDs may be generated using nextRandom or your favorite instance of Random.
• We have an implementation of generating a UUID from the hardware MAC address and current system time in Data.UUID.V1.
• For name-based generation of UUIDs using SHA-1 hashing see Data.UUID.V5.

Documentation

data UUID

The UUID type. A Random instance is provided which produces version 4 UUIDs as specified in RFC 4122. The Storable and Binary instances are compatible with RFC 4122, storing the fields in network order as 16 bytes.

Instances

Eq UUID

Defined in Data.UUID.Internal

Methods

(==) :: UUID -> UUID -> Bool

(/=) :: UUID -> UUID -> Bool

Data UUID

Defined in Data.UUID.Internal

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> UUID -> c UUID

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c UUID

toConstr :: UUID -> Constr

dataTypeOf :: UUID -> DataType

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c UUID)

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c UUID)

gmapT :: (forall b. Data b => b -> b) -> UUID -> UUID

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> UUID -> r

gmapQr :: (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> UUID -> r

gmapQ :: (forall d. Data d => d -> u) -> UUID -> [u]

gmapQi :: Int -> (forall d. Data d => d -> u) -> UUID -> u

gmapM :: Monad m => (forall d. Data d => d -> m d) -> UUID -> m UUID

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> UUID -> m UUID

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> UUID -> m UUID

Ord UUID

Defined in Data.UUID.Internal

Methods

compare :: UUID -> UUID -> Ordering

(<) :: UUID -> UUID -> Bool

(<=) :: UUID -> UUID -> Bool

(>) :: UUID -> UUID -> Bool

(>=) :: UUID -> UUID -> Bool

max :: UUID -> UUID -> UUID

min :: UUID -> UUID -> UUID

Read UUID

Defined in Data.UUID.Internal

Methods

readsPrec :: Int -> ReadS UUID

readList :: ReadS [UUID]

readPrec :: ReadPrec UUID

readListPrec :: ReadPrec [UUID]

Show UUID

Defined in Data.UUID.Internal

Methods

showsPrec :: Int -> UUID -> ShowS

show :: UUID -> String

showList :: [UUID] -> ShowS

Storable UUID

Defined in Data.UUID.Internal

Methods

sizeOf :: UUID -> Int

alignment :: UUID -> Int

peekElemOff :: Ptr UUID -> Int -> IO UUID

pokeElemOff :: Ptr UUID -> Int -> UUID -> IO ()

peekByteOff :: Ptr b -> Int -> IO UUID

pokeByteOff :: Ptr b -> Int -> UUID -> IO ()

peek :: Ptr UUID -> IO UUID

poke :: Ptr UUID -> UUID -> IO ()

Binary UUID

Defined in Data.UUID.Internal

Methods

put :: UUID -> Put

get :: Get UUID

putList :: [UUID] -> Put

Random UUID

Defined in Data.UUID.Internal

Methods

randomR :: RandomGen g => (UUID, UUID) -> g -> (UUID, g)

random :: RandomGen g => g -> (UUID, g)

randomRs :: RandomGen g => (UUID, UUID) -> g -> [UUID]

randoms :: RandomGen g => g -> [UUID]

randomRIO :: (UUID, UUID) -> IO UUID

randomIO :: IO UUID

toString :: UUID -> String

Convert a UUID into a hypenated string using lower-case letters. Example:

 toString $ fromString "550e8400-e29b-41d4-a716-446655440000"

fromString :: String -> Maybe UUID

If the passed in String can be parsed as a UUID, it will be. The hyphens may not be omitted. Example:

 fromString "c2cc10e1-57d6-4b6f-9899-38d972112d8c"

Hex digits may be upper or lower-case.

toByteString :: UUID -> ByteString

Encode a UUID into a ByteString in network order.

fromByteString :: ByteString -> Maybe UUID

Extract a UUID from a ByteString in network byte order. The argument must be 16 bytes long, otherwise Nothing is returned.

toWords :: UUID -> (Word32, Word32, Word32, Word32)

Covert a UUID into a sequence of Word32 values. Usefull for when you need to serialize a UUID and neither Storable nor Binary are appropriate. Introduced in version 1.2.2.

fromWords :: Word32 -> Word32 -> Word32 -> Word32 -> UUID

Create a UUID from a sequence of Word32. The opposite of toWords. Useful when you need a total function for constructing UUID values. Introduced in version 1.2.2.

null :: UUID -> Bool

Returns true if the passed-in UUID is the nil UUID.

nil :: UUID

The nil UUID, as defined in RFC 4122. It is a UUID of all zeros. null u iff u == nil.