[Lisp] Chapter 12 구조체(Structures)

1. Types

 - type & type-of : 어떤 데이터 타입인지 
- (typep '변수 '데이터타입) = t/nil

- (type-of '변수) = 데이터 타입리턴
- (typep #'list 'funtion) 함수는 #' 붙여줘야함

2. Structures
- Structures: 내가 정의한 데이터타입
- DEFSTRUCT: 새로운 데이터 타입 정의

(defstruct starship
	(captain nil)
	(name nil)
	(speed 0)
	(condition ‘green)
	(shields ‘down))
    
(setf s1 (make-starship)) //구조체 선언
(starship-captain) //구조체안 변수 접근

- 응용

(defun alert (x) ;; causing a starship to raise its shields
  (setf (starship-shields x) 'up)
  (if (equal (starship-condition x) 'green)
      (setf (starship-condition x) 'yellow))
  'shields-raised)
  
//초기화 하기
(setf s3 (make-starship :name "Reliant"
                        :shields ‘damaged))

- 구조체 equality 

(setf s5 (make-starship))
(setf s6 (make-starship))

(equal s5 s6)  >> nil
(equalp s5 s6) >> t

 

3. Inheritance(상속)

- :INCLUDE option : 구조체 상속하는 옵션이다

(defstruct ship
	(name nil)
	(captain nil)
	(crew-size nil))
    
(defstruct (starship (:include ship))
	(weapons nil)
	(shields nil))
    
(defstruct (supplyship (:include ship))
	(cargo nil))

 

4. Describe

- 구조체 내용을 출력해준다.