[原创]发现Lisp类指针操作,可以传递地址直接修改变量的值

Andyhon

By Herman Mayfarth
(defun ++ (&a) (set &a (1+ (eval &a))) )

;;=================

Command: (setq i 0)
0

Command: (++ 'i)
1

Command: (++ 'i)
2

Command: (++ 'i)
3

======
(setq ss (ssget) i -1)
(while (setq ee (ssname ss (++ 'i)))
  (setq dat (entget ee))
  ...
)  

^蓝¤天^

(defun c:tt(/ ch)
(defun ch (i j)
(set i (+ (eval i)(eval i)))
(set j (/ (eval j)(eval j)))
)
  (setq a 1 b 2)
  (print)(princ (list a b))
  (repeat 10 (ch 'a 'b)(print)(princ (list a b)))
  (princ)
)

czcxxx