Elm UUID

A universally unique identifier, or UUID, is a 128-bit number, usually represented as 32 hexidecimal digits, in the format 123e4567-e89b-42d3-a456-426655440000. This package provides a UUID type, and functions for reading, creating, randomly generating, inspecting and formatting UUIDs.

There are several versions and variants of UUID. Currently, creating the nil UUID, version 3, 4 and 5 UUIDs, and both variants are supported. However, all types can be understood and formatted.

Documentation

Elm 0.19.1 requires elm-uuid >= 2.2.1

A bugfix in elm 0.19.1 requires that one of elm-uuid's dependencies be updated, so please update this module to >= 2.2.1 to continue using in elm 0.19.1.

Warning about Version 4 UUIDs

Version 4 UUIDs have either 121 or 122 bits randomly allocated (depending on variant). I am neither an expert in entropy nor elm/random, but I suspect the Random.Generator does not provide the necessary entropy to fully utilise all those bits of randomness. Still, it is probably more than sufficient for most use cases.

Examples

import UUID exposing (UUID)
import Random


someSeed : Random.Seed
someSeed = Random.initialSeed 12345


makeIds : Int -> Random.Seed -> (List UUID, Random.Seed)
makeIds amount seed =
    Random.step (Random.list amount UUID.generator) seed


makeIds 3 someSeed
    |> Tuple.first
    |> List.map UUID.toVariant2
    |> List.map UUID.urn
--> [ "urn:uuid:fe86e741-b117-42ec-cade-4c0e16b4f15c"
--> , "urn:uuid:5fb50b3a-fa84-47eb-c55d-56e740013db2"
--> , "urn:uuid:695eec7b-3084-40e3-d94b-59028c466d1d"
--> ]


appID : UUID
appID = UUID.childNamed "myapplication.com" UUID.dns

UUID.canonical appID
--> "2ed74b2b-10eb-5b44-93be-69aa8952caac"

Modules

UUID