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

Methods

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

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

Data UUID

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

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

Methods

readsPrec :: Int -> ReadS UUID

readList :: ReadS [UUID]

readPrec :: ReadPrec UUID

readListPrec :: ReadPrec [UUID]

Show UUID

Methods

showsPrec :: Int -> UUID -> ShowS

show :: UUID -> String

showList :: [UUID] -> ShowS

Storable UUID

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

Methods

put :: UUID -> Put

get :: Get UUID

putList :: [UUID] -> Put

NFData UUID

Methods

rnf :: UUID -> ()

Hashable UUID

Methods

hashWithSalt :: Int -> UUID -> Int

hash :: UUID -> Int

Random UUID

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.

toText :: UUID -> Text

Convert a UUID into a hyphentated string using lower-case letters.

fromText :: Text -> Maybe UUID

If the passed in Text can be parsed as an ASCII representation of a UUID, it will be. The hyphens may not be omitted.

toASCIIBytes :: UUID -> ByteString

Convert a UUID into a hyphentated string using lower-case letters, packed as ASCII bytes into ByteString.

This should be equivalent to toString with pack.

fromASCIIBytes :: ByteString -> Maybe UUID

If the passed in ByteString can be parsed as an ASCII representation of a UUID, it will be. The hyphens may not be omitted.

This should be equivalent to fromString with unpack.

toLazyASCIIBytes :: UUID -> ByteString

Similar to toASCIIBytes except we produce a lazy ByteString.

fromLazyASCIIBytes :: ByteString -> Maybe UUID

Similar to fromASCIIBytes except parses from a lazy ByteString.

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. Useful 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.