자동차 : 6은 목록 오류가 아닙니다.

Question

CLisp에서 두 목록을 완벽하게 뒤섞어 쓰는 프로그램을 작성하려고합니다. 아래는 제 프로그램입니다. 프로그램 입력 내용을 (shuffle '(1 2 3) '(4 5 6))으로주었습니다. car:6 is not a list 오류가 발생했습니다.

(defun len (list) 
    (if list 
    (1+ (len (cdr list))) 
    0)) 

(defun my-append (A1 A2) 
    (cond 
     ((null A1) A2) 
     (t (cons A1 A2))) 
    ) 

(defun append (A1 A2) 
    (cond 
     ((null A2) A1) 
     (t (cons (car A1) (append (cdr A1) A2)))) 
) 

(defun shuffle (A1 A2) 
    (cond 
     ((/= (len A2) (len A1)) (princ "lengths of the lists are not equal")) 
     ((and (null A1) (null A2)) (princ "lists shuffled")) 
     (t (append 
      (my-append (car A1) (car A2)) 
      (shuffle (cdr A1) (cdr A2)) 
      ) 
     ) 
    ) 
) 

누군가 나를 도울 수 있습니까 ??

Answer 1

의 손 (shuffle '(3) '(6))에 의해 실행 보자 -

(append (my-append 3 6) (shuffle '() '()) -

1. (shuffle '(3) '(6))
2. myappend 반환 (cons 3 6), 그래서 우리는 (append (cons 3 6) nil)이 -
3. (cons 3 (append 6 nil))-
4. (cons 3 (cons (car 6) nil)) - 때문에 진리 (car 6) balks을 6은 목록이 아닙니다.

Answer 2

stackoverflow 커뮤니티가 제공 할 수있는이 특정 질문에 대한 특정 대답은이 질문에 도움이되지만 다음 질문에는 도움이되지 않습니다.

질문해야 할 질문은 다음과 같습니다. Common Lisp 디버거는 어떻게 사용합니까?

clisp을 사용 중이므로 clisp의 디버거에 익숙해집니다.

1. 시도 목록을 보려면 ?을 시도하십시오.
2. :bt을 사용하면 스택 추적을 얻을 수 있습니다. 이 경우

:

Break 1 [6]> :bt 
<1/289> #<SYSTEM-FUNCTION SHOW-STACK> 3 
<2/282> #<COMPILED-FUNCTION SYSTEM::PRINT-BACKTRACE> 
<3/276> #<COMPILED-FUNCTION SYSTEM::DEBUG-BACKTRACE> 
<4/267> #<SYSTEM-FUNCTION SYSTEM::READ-EVAL-PRINT> 2 
<5/264> #<COMPILED-FUNCTION SYSTEM::BREAK-LOOP-2-3> 
<6/260> #<SYSTEM-FUNCTION SYSTEM::SAME-ENV-AS> 2 
<7/246> #<COMPILED-FUNCTION SYSTEM::BREAK-LOOP-2> 
<8/244> #<SYSTEM-FUNCTION SYSTEM::DRIVER> 
<9/204> #<COMPILED-FUNCTION SYSTEM::BREAK-LOOP> 
<10/201> #<SYSTEM-FUNCTION INVOKE-DEBUGGER> 1 
<11/191> #<SYSTEM-FUNCTION CAR> 
[190] EVAL frame for form (CAR A1) 
[186] EVAL frame for form (CONS (CAR A1) (APPEND (CDR A1) A2)) 
<12/183> #<SPECIAL-OPERATOR COND> 
[182] EVAL frame for form (COND ((NULL A2) A1) (T (CONS (CAR A1) (APPEND (CDR A1) A2)))) 
[165] APPLY frame for call (APPEND '6 '"lists shuffled") 
<13/160> 
#<FUNCTION APPEND (A1 A2) (DECLARE (SYSTEM::IN-DEFUN APPEND)) 
    (BLOCK APPEND 
    (COND ((NULL A2) A1) (T (CONS (CAR A1) (APPEND (CDR A1) A2)))))> 2 
[159] EVAL frame for form (APPEND (CDR A1) A2) 
[154] EVAL frame for form (CONS (CAR A1) (APPEND (CDR A1) A2)) 
<14/151> #<SPECIAL-OPERATOR COND> 
[150] EVAL frame for form (COND ((NULL A2) A1) (T (CONS (CAR A1) (APPEND (CDR A1) A2)))) 
[133] APPLY frame for call (APPEND '(3 . 6) '"lists shuffled") 
<15/128> 
#<FUNCTION APPEND (A1 A2) (DECLARE (SYSTEM::IN-DEFUN APPEND)) 
    (BLOCK APPEND 
    (COND ((NULL A2) A1) (T (CONS (CAR A1) (APPEND (CDR A1) A2)))))> 2 
[127] EVAL frame for form (APPEND (MY-APPEND (CAR A1) (CAR A2)) (SHUFFLE (CDR A1) (CDR A2))) 
<16/124> #<SPECIAL-OPERATOR COND> 
[123] EVAL frame for form 
(COND ((/= (LEN A2) (LEN A1)) (PRINC "lengths of the lists are not equal")) 
((AND (NULL A1) (NULL A2)) (PRINC "lists shuffled")) 
(T (APPEND (MY-APPEND (CAR A1) (CAR A2)) (SHUFFLE (CDR A1) (CDR A2))))) 
[106] APPLY frame for call (SHUFFLE '(3) '(6)) 
<17/101> 
#<FUNCTION SHUFFLE (A1 A2) (DECLARE (SYSTEM::IN-DEFUN SHUFFLE)) 
    (BLOCK SHUFFLE 
    (COND 
    ((/= (LEN A2) (LEN A1)) (PRINC "lengths of the lists are not equal")) 
    ((AND (NULL A1) (NULL A2)) (PRINC "lists shuffled")) 
    (T 
    (APPEND (MY-APPEND (CAR A1) (CAR A2)) (SHUFFLE (CDR A1) (CDR A2))))))> 2 
[100] EVAL frame for form (SHUFFLE (CDR A1) (CDR A2)) 
[94] EVAL frame for form (APPEND (MY-APPEND (CAR A1) (CAR A2)) (SHUFFLE (CDR A1) (CDR A2))) 
<18/91> #<SPECIAL-OPERATOR COND> 
[90] EVAL frame for form 
(COND ((/= (LEN A2) (LEN A1)) (PRINC "lengths of the lists are not equal")) 
((AND (NULL A1) (NULL A2)) (PRINC "lists shuffled")) 
(T (APPEND (MY-APPEND (CAR A1) (CAR A2)) (SHUFFLE (CDR A1) (CDR A2))))) 
[73] APPLY frame for call (SHUFFLE '(2 3) '(5 6)) 
<19/68> 
#<FUNCTION SHUFFLE (A1 A2) (DECLARE (SYSTEM::IN-DEFUN SHUFFLE)) 
    (BLOCK SHUFFLE 
    (COND 
    ((/= (LEN A2) (LEN A1)) (PRINC "lengths of the lists are not equal")) 
    ((AND (NULL A1) (NULL A2)) (PRINC "lists shuffled")) 
    (T 
    (APPEND (MY-APPEND (CAR A1) (CAR A2)) (SHUFFLE (CDR A1) (CDR A2))))))> 2 
[67] EVAL frame for form (SHUFFLE (CDR A1) (CDR A2)) 
[61] EVAL frame for form (APPEND (MY-APPEND (CAR A1) (CAR A2)) (SHUFFLE (CDR A1) (CDR A2))) 
<20/58> #<SPECIAL-OPERATOR COND> 
[57] EVAL frame for form 
(COND ((/= (LEN A2) (LEN A1)) (PRINC "lengths of the lists are not equal")) 
((AND (NULL A1) (NULL A2)) (PRINC "lists shuffled")) 
(T (APPEND (MY-APPEND (CAR A1) (CAR A2)) (SHUFFLE (CDR A1) (CDR A2))))) 
[40] APPLY frame for call (SHUFFLE '(1 2 3) '(4 5 6)) 
<21/35> 
#<FUNCTION SHUFFLE (A1 A2) (DECLARE (SYSTEM::IN-DEFUN SHUFFLE)) 
    (BLOCK SHUFFLE 
    (COND 
    ((/= (LEN A2) (LEN A1)) (PRINC "lengths of the lists are not equal")) 
    ((AND (NULL A1) (NULL A2)) (PRINC "lists shuffled")) 
    (T 
    (APPEND (MY-APPEND (CAR A1) (CAR A2)) (SHUFFLE (CDR A1) (CDR A2))))))> 2 
[34] EVAL frame for form (SHUFFLE '(1 2 3) '(4 5 6)) 
Printed 21 frames 

천천히 그것을 통해 읽어 보시기 바랍니다. 처음 10 줄을 무시할 수 있습니다. 그것들은 clisp의 디버거 자체의 인공물입니다. 그러나 나머지는 당신에게 당신의 프로그램이 무엇을하고 있는지에 대한 이해를 줄 것입니다.