一个简单的 CD 数据库

创建CD

(defun make-cd (title artist rating ripped)
    (list :title title :artist artist :rating rating :ripped ripped))

全局变量 holder

(defvar *db* nil)
(defun add-record (cd) (push cd *db))

星号在 Lisp 中约定为全局变量
宏 push

查看

(defun dump-db()
    (dolist (cd *db*)
        (format t "~{~a:~10t~a~%~}~%" cd)))

宏 dolist
dolist 的简单用法

(dolist (item (list 1 2 3)) (format t "~a" item))

也可以

(format t "~{~a~}" (list 1 2 3))