uuid-1.2.1: For creating, comparing, parsing and printing Universally Unique Identifiers




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.

For generating UUIDs, check out Data.UUID.V1, Data.UUID.V5 and System.Random.



data UUID Source

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.

toString :: UUID -> StringSource

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

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

fromString :: String -> Maybe UUIDSource

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 -> ByteStringSource

Encode a UUID into a ByteString in network order.

fromByteString :: ByteString -> Maybe UUIDSource

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

null :: UUID -> BoolSource

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

nil :: UUIDSource

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