class

Uuid

@Serializable { simple=true }
const class Uuid : Obj

Universally Unique Identifier. UUIDs are 128-bit identifiers which are unique across space and time making them ideal for naming without a central naming authority. Fantom's UUIDs are loosely based on RFC 4122 with the following parts used in the generation:

  • 8 bytes: nanosecond ticks since 1 Jan 2000 UTC
  • 2 bytes: sequence number
  • 6 bytes: node address

The sequence number is initialized from a randomized number, and helps protect against collisions when the system clock is changed. The node address is ideally mapped to the MAC address if available, or the IP address hashed with a random number.

No guarantee is made how the bytes are laid out. Future versions might hash these bytes, or use alternate mechanisms.

The string format for the UUID follows the canonical format of 32 hexadecimal digits displayed in five groups for "8-4-4-4-12". For example:

03f0e2bb-8f1a-c800-e1f8-00623f7473c4

constructors fromStr

Parse a UUID according to the string format defined in the class header documentation

make

Generate a new UUID globally unique in space and time

methods bitsLo

Get the least significant 64 bits of this 128 bit UUID

toStr

Return the string representation of this UUID

compare

Compare based on the 128 bit value which will naturally result in sorts by created timestamp

makeBits

Create a 128-bit UUID from two 64-bit integers

equals

Return if the specified object is a Uuid with the same 128 bits

bitsHi

Get the most significant 64 bits of this 128 bit UUID

hash

Hashcode is defined as bitsHi ^ bitsLow

bitsHi Int bitsHi()

Get the most significant 64 bits of this 128 bit UUID.

bitsLo Int bitsLo()

Get the least significant 64 bits of this 128 bit UUID.

compare virtual Int compare(Obj that)

Compare based on the 128 bit value which will naturally result in sorts by created timestamp.

equals virtual Bool equals(Obj? that)

Return if the specified object is a Uuid with the same 128 bits.

fromStr static new fromStr(Str s, Bool checked)

Parse a UUID according to the string format defined in the class header documentation. If invalid format and checked is false return null, otherwise throw ParseErr.

hash virtual Int hash()

Hashcode is defined as bitsHi ^ bitsLow

make static new make()

Generate a new UUID globally unique in space and time.

makeBits static Uuid makeBits(Int hi, Int lo)

Create a 128-bit UUID from two 64-bit integers.

toStr virtual Str toStr()

Return the string representation of this UUID. See class header for string format.

Haxall 4.0.5 ∙ 24-Feb-2026 14:33 EST