code.delx.au - gnu-emacs-elpa/blob - chess-database.el

   1 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
   2 ;;
   3 ;; Basic code for manipulating game databases
   4 ;;
   5 ;; $Revision$
   6
   7 (defvar chess-database-event-handler nil)
   8
   9 (make-variable-buffer-local 'chess-database-event-handler)
  10
  11 (defmacro chess-with-current-buffer (buffer &rest body)
  12   `(let ((buf ,buffer))
  13      (if buf
  14          (with-current-buffer buf
  15            ,@body)
  16        ,@body)))
  17
  18 (chess-message-catalog 'english
  19   '((no-such-style . "There is no such chess database module '%s'")))
  20
  21 (defun chess-database-open (module file)
  22   "Returns the opened database object, or nil."
  23   (let* ((name (symbol-name module))
  24          (handler (intern-soft (concat name "-handler")))
  25          buffer)
  26     (unless handler
  27       (chess-error 'no-such-database name))
  28     (when (setq buffer (funcall handler 'open file))
  29       (with-current-buffer buffer
  30         (setq chess-database-event-handler handler)
  31         (add-hook 'kill-buffer-hook 'chess-database-close nil t)
  32         (add-hook 'after-revert-hook 'chess-database-rescan nil t)
  33         (current-buffer)))))
  34
  35 (defsubst chess-database-command (database event &rest args)
  36   (chess-with-current-buffer database
  37     (apply 'chess-database-event-handler nil (current-buffer)
  38            event args)))
  39
  40 (defun chess-database-close (database)
  41   (let ((buf (or database (current-buffer))))
  42     (when (buffer-live-p buf)
  43       (chess-database-command buf 'save)
  44       (chess-database-command buf 'close)
  45       (with-current-buffer buf
  46         (remove-hook 'kill-buffer-hook 'chess-database-quit t))
  47       (kill-buffer buf))))
  48
  49 (defun chess-database-save (database)
  50   (chess-database-command database 'save))
  51
  52 (defun chess-database-rescan (&optional database)
  53   (chess-database-command database 'rescan))
  54
  55 (defun chess-database-count (database)
  56   (chess-database-command database 'count))
  57
  58 (defun chess-database-read (database index)
  59   (chess-database-command database 'read index))
  60
  61 (defun chess-database-write (database game)
  62   (chess-database-command database 'write game))
  63
  64 (defun chess-database-replace (database game &optional index)
  65   (chess-database-command database 'replace game index))
  66
  67 (defun chess-database-query (database &rest terms)
  68   (chess-database-command database 'query terms))
  69
  70 (defun chess-database-event-handler (game database event &rest args)
  71   (if (eq event 'shutdown)
  72       (chess-database-close database)
  73     (chess-with-current-buffer database
  74       (apply chess-database-event-handler event args))))
  75
  76 (provide 'chess-database)
  77
  78 ;;; chess-database.el ends here