数据结构

(list 1 2 3)                            ; => (1 2 3)
(list 1 2 3 'a 'b 'c)                   ; => (1 2 3 A B C)

(type-of '(1 2 3)) ; => CONS
(typep '(1 2 3) 'list) ; => T

lispobj
alloc_cons(lispobj car, lispobj cdr)
{
    struct cons *ptr =
        (struct cons *)pa_alloc(ALIGNED_SIZE(sizeof(struct cons)),
                                BOXED_PAGE_FLAG);

    ptr->car = car;
    ptr->cdr = cdr;

    return make_lispobj(ptr, LIST_POINTER_LOWTAG);
}

(cons 1 2)                              ; => (1 . 2)

(length '(1 (2 3)))                     ; => 2

(eq '() nil)                            ; => T

(equal '(1 2 3) '(1 2 3)) ; => T
(equal '(1 2 3) '(1 2 3 nil)) ; => NIL

(listp nil) ; => T
(consp nil) ; => NIL

first
last
second
third
fourth
fifth
sixth
seventh
eighth
ninth
tenth

(rest '(1 2 3 4))                       ; => (2 3 4)

(car '(1 2 3)) ; => 1
(cdr '(1 2 3)) ; => (2 3)

(car (cdr '(1 2 3))) ; => 2
(cadr '(1 2 3)) ; => 2，和以上是等同的

(cdar '(1 2 3)) ; => ERROR: The value 1 is not of type LIST.
(cdar '((1 2) 3)) ; => (2)

(car (cdr (cdr '(1 2 3 4)))) ; => 3
(caddr '(1 2 3 4)) ; => 3

(car (car (cdr (cdr '(1 2 (3 4) 5)))))  ; => 3
(caaddr '(1 2 (3 4) 5))                 ; => 3

;;; 左边指针指向存储了“1”的内存地址，右边指针指向存储了“2”的内存地址
(cons 1 2)                     ; => (1 . 2)
(cons 1 nil)                   ; => (1)
(cons 1 (cons 2 nil))          ; => (1 2)

(vector 1 2 3)                          ; => #(1 2 3)
;;; 与 vector 等价的符号
#(1 2 3)                                ; => #(1 2 3)
(type-of #(1 2 3))                      ; => (SIMPLE-VECTOR 3)
                                        ; SIMPLE-ARRAY 表示没有设置 adjustable 和 fill pointer 的数组，后面讲到

(elt #(1 2 3) 1)                        ; => 2

(defvar a-array (make-array 3 :fill-pointer 0))
(vector-push 0 a-array)                 ; => 0
(vector-push 1 a-array)                 ; => 1
(vector-push 2 a-array)                 ; => 2
(vector-push 3 a-array)                 ; => NIL

(defvar adj-array (make-array 3 :fill-pointer 0 :adjustable t))

;;; 调用 vector-push-extend，当超出数组大小时自动扩充空间
(loop for i from 1 to 100 do (vector-push-extend i adj-array)) ; => NIL
adj-array ; => #(1 2 3 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100)

(defvar hello "hello world")
(aref hello 1)                          ; => #\e
;;; 修改元素
(setf (aref hello 0) #\H)               ; => #\H
hello                                   ; => "Hello world"

;;; intersection 函数求两个集合的交集，函数原型如下：
;;; (intersection list1 list2 &key key (test #'eql) test-not)
(intersection '(1 2 3) '(4 5 6))        ; => NIL
(intersection '(1 2 3) '(1 3 5))        ; => (3 1)

;;; union 函数求两个集合的并集，函数原型如下：
;;; (union list1 list2 &key key (test #'eql) test-not)
(union '(1 2 3) '(4 5 6))               ; => (3 2 1 4 5 6)
(union '(1 2 3) '(1 2 3 4))             ; => (4 1 2 3)

;;; set-difference 函数求两个集合的集合差，原型如下：
;;; (set-difference list1 list2 &key key (test #'eql) test-not)
(set-difference '(1 2 3) '(1 2 3))      ; => NIL
(set-difference '(1 2 3) '(1 2))        ; => (3)

;;; subsetp 函数提供了判断一个集合是否是另个集合的子集，subsetp 原型如下：
;;; (subsetp list1 list2 &key key (test #'eql) test-not)
(subsetp '(a e) '(a e i o u))           ; => T
(subsetp '(b c) '(a e i o u))           ; => NIL

;;; 定义结构体
(defstruct my-info (name "lu4nx") (site "www.shellcodes.org")) ; => MY-INFO
;;; 结构体为每个成员分配了默认值，如果不需要默认值：
(defstruct my-info1 name site)          ; => MY-INFO1

;;; 创建新示例以“make-类型名”形式的函数创建：
(make-my-info) ; => #s(MY-INFO :NAME "lu4nx" :SITE "www.shellcodes.org")
                                        ; “#S”是 Common Lisp 显示结构体的符号。

;;; 创建时指定元素的值：
(make-my-info :name "lx")               ; => #S(MY-INFO :NAME "lu4nx" :SITE "www.shellcodes.org")

;;; 结构体的谓词函数，在这里的实例中是 my-info-p：
(my-info-p (make-my-info))              ; => T

;;; 访问结构体成员：
(my-info-name (make-my-info))           ; => "lu4nx"

;;; 修改结构体成员：
(defvar my-self (make-my-info))
my-self                                 ; => #S(MY-INFO :NAME "lu4nx" :SITE "www.shellcodes.org")
(setf (my-info-name my-self) "lux")
my-self                                 ; => #S(MY-INFO :NAME "lux" :SITE "www.shellcodes.org")

;;; 结构体继承：创建新结构体时，可继承原结构体的成员。
;; 如，继承 my-info 结构体
(defstruct (new-my-info (:include my-info)) (sex "man"))
(make-new-my-info) ; => #S(NEW-MY-INFO :NAME "lu4nx" :SITE "www.shellcodes.org" :SEX "man")