;; This file:
;;   http://angg.twu.net/LISP/seibel-02.lisp.html
;;   http://angg.twu.net/LISP/seibel-02.lisp
;;           (find-angg "LISP/seibel-02.lisp")
;; Author: Eduardo Ochs <eduardoochs@gmail.com>
;;
;; (defun s2 () (interactive) (find-angg "LISP/seibel-02.lisp"))
;; (find-es "lisp" "seibel-cap02")

* (eepitch-sbcl)
* (eepitch-kill)
* (eepitch-sbcl)
(getf (list :a 1 :b 2 :c 3) :a)
(getf (list :a 1 :b 2 :c 3) :c)

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

(make-cd "Roses" "Kathy Mattea" 7 t)

(defvar *db* nil)

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

(add-record (make-cd "Roses" "Kathy Mattea" 7 t))
(add-record (make-cd "Fly" "Dixie Chicks" 8 t))
(add-record (make-cd "Home" "Dixie Chicks" 9 t))

*db*

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

(dump-db)

(format t "~a" "Dixie Chicks")
(format t "~a" :title)
(format t "~a:~10t~a" :artist "Dixie Chicks")

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

(dump-db)

(defun prompt-read (prompt)
  (format *query-io* "~a: " prompt)
  (force-output *query-io*)
  (read-line *query-io*))

(defun prompt-for-cd ()
  (make-cd
   (prompt-read "Title")
   (prompt-read "Artist")
   (prompt-read "Rating")
   (prompt-read "Ripped [y/n]")))

(parse-integer (prompt-read "Rating"))
9

(parse-integer (prompt-read "Rating") :junk-allowed t)
9 ab

(or (parse-integer (prompt-read "Rating") :junk-allowed t) 0)
9

(y-or-n-p "Ripped [y/n]: ")
y

(defun prompt-for-cd ()
  (make-cd
   (prompt-read "Title")
   (prompt-read "Artist")
   (or (parse-integer (prompt-read "Rating") :junk-allowed t) 0)
   (y-or-n-p "Ripped [y/n]: ")))

(defun add-cds ()
  (loop (add-record (prompt-for-cd))
      (if (not (y-or-n-p "Another? [y/n]: ")) (return))))

(add-cds)
Rockin' the Suburbs
Ben Folds
6
y
y
Give Us a Break
Limpopo
10
y
y
Lyle Lovett
Lyle Lovett
9
y
n

(defun save-db (filename)
  (with-open-file (out filename
                   :direction :output
                   :if-exists :supersede)
    (with-standard-io-syntax
      (print *db* out))))

(save-db "/tmp/my-cds.db")

(defun load-db (filename)
  (with-open-file (in filename)
    (with-standard-io-syntax
      (setf *db* (read in)))))

(load-db "/tmp/my-cds.db")

(remove-if-not #'evenp '(1 2 3 4 5 6 7 8 9 10))

(remove-if-not #'(lambda (x) (= 0 (mod x 2))) '(1 2 3 4 5 6 7 8 9 10))

(remove-if-not #'(lambda (x) (= 1 (mod x 2))) '(1 2 3 4 5 6 7 8 9 10))

(remove-if-not
  #'(lambda (cd) (equal (getf cd :artist) "Dixie Chicks")) *db*)

(defun select-by-artist (artist)
  (remove-if-not
   #'(lambda (cd) (equal (getf cd :artist) artist))
   *db*))

(defun select (selector-fn)
  (remove-if-not selector-fn *db*))

(select #'(lambda (cd) (equal (getf cd :artist) "Dixie Chicks")))

(defun artist-selector (artist)
  #'(lambda (cd) (equal (getf cd :artist) artist)))

(select (artist-selector "Dixie Chicks"))

(defun foo (a b c) (list a b c))

(defun foo (&key a b c) (list a b c))

(defun foo (&key a (b 20) (c 30 c-p)) (list a b c c-p))

(defun where (&key title artist rating (ripped nil ripped-p))
  #'(lambda (cd)
      (and
       (if title    (equal (getf cd :title)  title)  t)
       (if artist   (equal (getf cd :artist) artist) t)
       (if rating   (equal (getf cd :rating) rating) t)
       (if ripped-p (equal (getf cd :ripped) ripped) t))))

(select (where :artist "Dixie Chicks"))

(select (where :rating 10 :ripped nil))

(defun update (selector-fn &key title artist rating (ripped nil ripped-p))
  (setf *db*
        (mapcar
         #'(lambda (row)
             (when (funcall selector-fn row)
               (if title    (setf (getf row :title) title))
               (if artist   (setf (getf row :artist) artist))
               (if rating   (setf (getf row :rating) rating))
               (if ripped-p (setf (getf row :ripped) ripped)))
             row) *db*)))

(update (where :artist "Dixie Chicks") :rating 11)

(select (where :artist "Dixie Chicks"))