(defmacro sort-places (. places)
  (caseql (len places)
    ((0 1) nil)
    (2 (with-gensyms (p0 p1)
         ^(placelet ((p0 (read-once ,[places 0]))
                     (p1 (read-once ,[places 1])))
            (if (greater p0 p1)
              (swap p0 p1)))))
    (3 (with-gensyms (p0 p1 p2)
         ^(placelet ((p0 (read-once ,[places 0]))
                     (p1 (read-once ,[places 1]))
                     (p2 (read-once ,[places 2])))
            (if (greater p0 p1)
              (swap p0 p1))
            (if (greater p1 p2)
              (swap p1 p2))
            (if (greater p0 p1)
              (swap p0 p1)))))
    (t (let ((gens [mapcar (ret (gensym)) places]))
         (with-gensyms (vec)
           ^(placelet ,(zip gens places)
              (let ((,vec (vec ,*gens)))
                (nsort ,vec)
                (set ,*(append-each ((g gens)
                                     (i 0))
                         ^(,g [,vec ,i]))))))))))

(prinl (sort-places))

(let ((x 1))
  (sort-places x)
  (prinl x))

(let ((x 2)
      (y 1))
  (sort-places x y)
  (prinl (list x y)))

(let ((a 3)
      (b 2)
      (c 1))
  (sort-places a b c)
  (prinl (list a b c)))

(let ((a 4)
      (b 3)
      (c 2)
      (d 1))
  (sort-places a b c d)
  (prinl (list a b c d)))