mutable type definition helper .. to automatically create all the setters and getters

defmutabletype.clj

(defmacro defmutabletype [type-name members]
  (let [proto-name (symbol (str "I" (name type-name)))
        member-setter-names (map #(symbol (str (name %) "!")) members)
        member-setter-prototypes (map (fn [setter-name] `(~setter-name [this# newval#])) member-setter-names)
        member-setter-fns (map (fn [setter-name member-name] `(~setter-name [this# newval#] (set! ~member-name newval#))) member-setter-names members)
        member-getter-prototypes (map (fn [member-name] `(~member-name [this#])) members)
        member-getter-fns (map (fn [member-name] `(~member-name [this#] ~member-name)) members)
        annotated-members (vec (map (fn [name] (with-meta name (assoc (meta name) :volatile-mutable true))) members))]
  `(do
     (defprotocol ~proto-name
       ~@member-getter-prototypes
       ~@member-setter-prototypes)
     (deftype ~type-name ~annotated-members
       ~proto-name
       ~@member-getter-fns
       ~@member-setter-fns))))