Question

Is there any (reasonable) way to write this macro as a function?

(defmacro assocTop
          [v & args]
          `(push (pop ~v)
                 (assoc (peek ~v) ~@args)))

Given a vector of maps and some associations, the macro code applies the associations to the top/peeked map.

However, when trying to write it as a function, I can’t figure out how to expand the ~@args in a legitimate way. In normal functions, is there a way to turn args, which I believe has the form (:a 3 :bb 44 :cd 90,...) into :a 3 :bb 44 :cd 90,... ,i.e. without the parens?

Answer 1

I guess you should use apply which will apply assoc to (peek v) and expanded args.

(defn assocTop
  [v & args]
  (push (pop v)
        (apply assoc (peek v) args)))
(=
  (assocTop [{:a :b} {:c :d} {:e :f, :g :h}] :e :z)
  [{:a :b} {:c :d} {:g :h, :e :z}]) ; => true