disqualified

Tiny Clojure(Script) library for conversion between qualified and unqualified keyword maps using clojure.spec definitions.

Setup

Leiningen/boot:

[cjsauer/disqualified "0.1.0"]

tools.deps:

cjsauer/disqualified {:mvn/version "0.1.0"}

Usage

(ns my-project.core
  (:require [cjsauer.disqualified :refer [qualify-map unqualify-map]]))

;; Define some specs for humans
(s/def :human/name string?)
(s/def :human/age number?)
(s/def ::human (s/keys :req [:human/name
                             :human/age]))

(def human {:human/age 42
            :human/name "Jeff"
            :other 12})

;; Strip namespaces off all keyword keys
(unqualify-map human)
;; {:age 42, :name "Jeff", :other 12}

(def unq-human {:age 42
                :name "Brad"
                :other 12})

;; Qualify the keys of the map using the given spec as the guide.
;; Notice how keywords not in the spec are simply ignored.
(qualify-map unq-human ::human)
;; {:human/age 42, :human/name "Brad", :other 12} 

;; An overrides map can be provided to customize behavior
(qualify-map unq-human ::human {:other :something/else})
;;{:human/age 42, :human/name "Brad", :something/else 12}

Limitations

qualify-map only works for s/keys spec definitions. It is not useful for s/map-of spec definitions in which the target keywords can not be inferred.

qualify-map uses the keys specified inside of the :req vector given to s/keys to infer target keywords. This means that it can conflict with the optionality semantics (:opt) of s/keys. To work around this, you may want to create a separate spec definition specifcally for qualification, for example:

;; Standard spec
(s/def ::human (s/keys :req [...] :opt [...]))

;; Spec specifically for qualifying keys
(s/def ::human-qualifier (s/keys :req [...]))

This conflation of key selection and key optionality will hopefully be fixed in "spec 2", as hinted by Rich Hickey in his talk Maybe Not.