`[super viewDidLoad]`约定(`[super viewDidLoad]` convention)

 ＃（车S）没有意义。 语法存在，但意味着符号CAR和S的向量。 
 
 使用 
 
(funcall (first somelist) someargument)
 
 要么 
 
(apply (first somelist) a-list-of-arguments)
 
 你的函数是非Lispy格式的。 
 
 后面的括号不会用在正确的Lisp代码中。 你也不需要引用数字。 数字是自我评估，他们评估自己。 此外，我们现在可能更倾向于CAR和REST over CDR。 功能相同，但名称更好。 每当我们处理简单的列表时，都会使用FIRST，SECOND，THIRD，...和REST。 
 
(defun aritheval (S)
  (funcall (cond ((eq '+ (car S)) #'+)
                 ((eq '- (car S)) #'-)
                 ((eq '* (car S)) #'*)
                 ((eq '/ (car S)) #'/))
            2 3)))
 
 由于符号可以用作全局函数的名称，因此以上不是必需的。 
 
 下面的这个函数也是一样的，因为从符号到函数的映射是相同的。 
 
(defun aritheval (s)
  (funcall (first s) 2 3)))

#(car S) makes no sense. The syntax exists but means a vector with symbols CAR and S.
 
use
 
(funcall (first somelist) someargument)
 
or
 
(apply (first somelist) a-list-of-arguments)
 
Your function is non-Lispy formatted.
 
Trailing parentheses are not used in proper Lisp code. You also don't need to quote numbers. Numbers are self-evaluating, they evaluate to themselves. Also we now may prefer FIRST over CAR and REST over CDR. The functions do the same, but the names are better. Whenever we deal with simple lists, FIRST, SECOND, THIRD, ... and REST are used.
 
(defun aritheval (S)
  (funcall (cond ((eq '+ (car S)) #'+)
                 ((eq '- (car S)) #'-)
                 ((eq '* (car S)) #'*)
                 ((eq '/ (car S)) #'/))
            2 3)))
 
Since symbols can be used as names for global functions, above is not necessary.
 
This function below does the same, given the mapping from symbol to function is the same.
 
(defun aritheval (s)
  (funcall (first s) 2 3)))