edvorg / lenses

Simple proof-of-concept lenses implementation in Clojure

lenses

Simple proof-of-concept lenses implementation in Clojure

Usage

(ns ...
  (:require [rocks.clj.lenses.core :refer [lens-values
                                           lens-keys
                                           in
                                           out
                                           out-all
                                           map
                                           ->
                                           ->>]]))

(-> {:data {:foo [1 2 3]
            :bar {:baz 1
                  :qux 2}}}

    (in :data) ;; zoom into data

    (in :foo) ;; zoom into :foo
    (conj 4) ;; add 4 to [1 2 3]
    (in 0) ;; zoom into first element of array
    (+ 5) ;; 5 to first element of array
    out ;; zoom out
    out ;; zoom out

    (in :bar) ;; zoom into :bar
    (assoc :tux 3) ;; add :tux -> 3 mapping
    lens-values ;; zoom into values
    (map inc) ;; increment all values
    out ;; zoom out

    lens-keys ;; lens in keys
    (map name) ;; convert all keywords to strings
    out-all ;; zoom outmost
    )

    => {:data {:foo [6 2 3 4]
        :bar {"baz" 2
              "qux" 3
              "tux" 4}}}

License

Copyright © 2018 Eduard Knyshov

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