;; Macro bodies the .fln printer must classify from their definitions:
;; test_syntax converts this file, runs both and wants the same output.

;; Counts its body forms: a let taking in the form after it would change the
;; count, so the body is not one a let may be flattened in.
(defmacro counted [& body]
  (let [two (= (length body) 2)]
    `(do (println ~(if two (Form.Sym {.s "true"}) (Form.Sym {.s "false"}))) ~@body)))

;; Replaces the prelude's unless, and counts too.
(defmacro unless [& args]
  (let [two (= (length args) 3)]
    `(do (println ~(if two (Form.Sym {.s "true"}) (Form.Sym {.s "false"}))) ~@(form-rest args 1))))

;; The body once in a do and once as a vector's elements.
(defmacro vtwice [& body]
  `(do ~@body (println (length [~@body]))))

;; The first body form is the loop's test.
(defmacro labelled [& body]
  `(while :l ~@body))

;; A guard that only asks whether there is a body: a body run in order.
(defmacro guarded [& args]
  (if (< (length args) 1)
    `(do)
    `(do ~@args)))

(defn main [] i32
  (counted
    (let [x 1] (println x))
    (println 2))
  (unless false
    (let [y 3] (println y))
    (println 4))
  (vtwice
    (let [z 5] (println z) z)
    6)
  (labelled
    (let [go false] go)
    (println 9))
  (let [g 0]
    (guarded
      (let [g 1] (println g))
      (println g)))
  0)