(seq
  (def break builtins.flow.break)
  (def continue builtins.flow.continue)
  (def loop builtins.flow.loop)

  (defmacro return []
    (builtins.flow.return $%% null))

  (defmacro while [cond] (loop
    (if (eq? $cond :false) (break) :null)
    $%&))

  (defmacro do-while [cond] (loop
    $%&
    (if (eq? $cond :false) (break) :null)))

  (defmacro for [var iter] (vec.map
    (lambda [x] (seq
      (def $var x)
      $%&))
    (vec.from $iter)
  ))
)