Minor project structure improvement.

frontend/uxbox/util/lens.cljs

@@ -0,0 +1,28 @@
+(ns uxbox.util.lens
+  (:refer-clojure :exclude [derive])
+  (:require [cats.labs.lens :as l]))
+
+(defn dep-in
+  [where link]
+  {:pre [(vector? where) (vector? link)]}
+  (l/lens
+   (fn [s]
+     (let [value (get-in s link)
+           path (conj where value)]
+       (get-in s path)))
+   (fn [s f]
+     (throw (ex-info "Not implemented" {})))))
+
+(defn getter
+  [f]
+  (l/lens f #(throw (ex-info "Not implemented" {}))))
+
+(defn derive
+  [a path]
+  (l/focus-atom (l/in path) a))
+
+(defn focus
+  ([state]
+   (l/focus-atom l/id state))
+  ([lens state]
+   (l/focus-atom lens state)))