Declare Member Variables with gen-class in Clojure

Question

I\'m learning how to extend Java classes in Clojure, but I don\'t see a way declare new member variables; I only see a way for methods.

(ns test.aclass
  (:g         


        

Answer 1

The body of a proxy is a lexical closure, so you can just close around whatever variables you need. If, God forbid, you need to mutate them, then close around an atom:

(defn lying-list [init-size]
  (let [the-size (atom init-size)]
    (proxy [java.util.ArrayList] []
      (size [] @the-size)
      (remove [idx] (reset! the-size idx), true))))

There's really no need for actual Java fields here.