;This macro was intended to create a looping function
;It defines a function "repeat-once" which may be called by itself
;But it fails "Unable to resolve symbol: repeat-once"

(defmacro do-once [expr]
  "expr is of the form {:bind [bindings] :body body}. apply bindings once to body.

success example:
(do-once {:bind [x 1 y 2] :body (+ x y)})
;;=> 3
fail example:
(do-once {:bind [x 5 y 2] :body (if (> x y) (repeat-once (dec x) y) true)})
;;=> CompilerException java.lang.RuntimeException: Unable to resolve symbol: repeat-once in this context, compiling:
"
  (let [
        body (expr :body)
        bind-symbols (take-nth 2 (expr :bind))
        bind-values (take-nth 2 (rest (expr :bind)))
        ]
    `(let [
           ~'repeat-once (fn ~(vec  bind-symbols) ~body)
           ]
     (apply ~'repeat-once ~(vec bind-values)))))