Macro: DO-RANGE

Source

(defmacro do-range ((index &optional min max step return-value)
                    &body body)
  (assert (or min max)
          (min max)
          "Must specify at least MIN or MAX")
  `(loop
      for ,index ,@(when min `(from ,min))
                 ,@(when max `(upto ,max))
                 ,@(when step `(by ,step))
      do (progn ,@body)
      finally (return ,return-value)))