uuid tag literal

A universally unique identifier (UUID).

  1. #uuid "8-4-4-4-12" - numbers represent the number of hex digits
  2. #uuid "97bda55b-6175-4c39-9e04-7c0205c709dc" - actual example

Representing UUIDs with #uuid rather than just a plain string has the following benefits:

  1. the reader will throw an exception on malformed UUIDs
  2. its UUID type is preserved and shown when serialized to edn.

Creating UUIDs - Clojure

In Clojure, call the randomUUID method of the java.util.UUID class

  1. (java.util.UUID/randomUUID)

This returns a UUID tagged literal.

  1. (java.util.UUID/randomUUID)
  2. ;; => #uuid "44f3ffd7-6702-4b8a-af25-11bee4b5ec4f"

Looking at the type we can see its a Java object from the java.util.UUID class:

  1. (type (java.util.UUID/randomUUID))
  2. ;; => java.util.UUID

Creating UUIDs - ClojureScript

Randomly generate a UUID in ClojureScript:

cljs.core/random-uuid

To label a value as a UUID:

cljs.core/uuid

Hint::uuid does not validate the value

The ClojureScript documentation states that uuid? does not perform validation.

Testing for a uuid

uuid? tests a given value and returns true if it is a uuid tagged literal value.

tagged-literal? is the more general function for any tagged values.