keypin

Key lookup on steroids in Clojure.

Why Keypin?

• Key lookup on any clojure.lang.ILookup or java.util.Map type
  • Clojure maps
  • Clojure vectors
  • java.util.Properties instances
  • Destructuring
• Optional value parsing
• Optional value validation
• Fail-fast error reporting
• Optional default value (when key is missing)
• Reading config files
  • Out of the box support for .edn and .properties files
  • Extensible design for other config file types (JSON, YAML etc.)
  • Read config file from filesystem and classpath (in that order)
  • Chained config files (via parent key, child properties override parent)
  • Multi-parent chaining
  • Template value resolution in string values (environment variables override others)
  • Cascading lookup ${foo|bar|baz} - foo is looked up, followed by bar, then baz
• Writing config files

Usage

Clojars coordinates: [keypin "0.7.5"]

Requires Java 7 or higher.

Quick start

(require '[keypin.core :refer [defkey letval] :as k])
(require '[keypin.util :as u])

;; key with constraints
(defkey
  ip   [:ip]
  port [:port #(< 1023 % 65535) "Port number" {:parser u/str->int}])

;; lookup
(ip   {:ip "0.0.0.0" :port "5000"})  ; returns "0.0.0.0"
(port {:ip "0.0.0.0" :port "5000"})  ; returns 5000
(port {:ip "0.0.0.0"})               ; throws IllegalArgumentException

;; key with default value
(defkey
  ip   [:ip]
  port-optional [:port #(< 1023 % 65535) "Port number" {:parser u/str->int :default 3000}])

;; lookup
(port-optional {:ip "0.0.0.0" :port "5000"})  ; returns 5000
(port-optional {:ip "0.0.0.0"})               ; returns 3000

;; lookup form
(letval [{:defs [ip port-optional] :as m} {:ip "0.0.0.0"}]
  [ip port-optional m])  ; returns ["0.0.0.0" 3000 {:ip "0.0.0.0"}]

Documentation

See the documentation page

License

Copyright © 2015-2018 Shantanu Kumar (kumar.shantanu@gmail.com, shantanu.kumar@concur.com)

Distributed under the Eclipse Public License either version 1.0 or (at your option) any later version.