Hierarchical Specifications

Defining specifications for data that is hierarchical or nested in nature.

(ns practicalli.clojure
  (:require [clojure.spec.alpha :as spec]))

Example hierarchical data

{:top-level-key {:nested-key "value"}}

Individual specifications

(spec/def ::first-name string?)

(spec/def ::last-name string?)

(spec/def ::residential-address string?)

Composite Specification

keys function combines specifications to form a composite specification in the form of a Clojure hash-map.

(spec/def ::customer-details
  (spec/keys
    :req [::first-name ::last-name ::residential-address]))

Hierarchical Specification

A user account is composed of a user-id and customer details. Rather than include the individual customer details, the composite customer-details specification.

The ::user-id specification is as follows

(spec/def ::user-id uuid?)

The ::user-account specification

(spec/def ::user-account
  (spec/keys
    :req [::user-id ::customer-details]))

The following data structure will conform to the specification

{::user-id #uuid "97bda55b-6175-4c39-9e04-7c0205c709dc"
 ::customer-details {::first-name "Jenny"
                     ::last-name "Jetpack"
                     ::residential-address "Earth"}}