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

   1 ;;; chess-database.el --- Basic code for manipulating game databases
   2
   3 ;; Copyright (C) 2002, 2004, 2008  Free Software Foundation, Inc.
   4
   5 ;; Author: John Wiegley <johnw@gnu.org>
   6 ;; Maintainer: Mario Lang <mlang@delysid.org>
   7 ;; Keywords: data, games
   8
   9 ;; This program is free software; you can redistribute it and/or modify
  10 ;; it under the terms of the GNU General Public License as published by
  11 ;; the Free Software Foundation, either version 3 of the License, or
  12 ;; (at your option) any later version.
  13
  14 ;; This program is distributed in the hope that it will be useful,
  15 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 ;; GNU General Public License for more details.
  18
  19 ;; You should have received a copy of the GNU General Public License
  20 ;; along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21
  22 ;;; Code:
  23
  24 (require 'chess-message)
  25
  26 (defgroup chess-database nil
  27   "Generic interface to chess database modules."
  28   :group 'chess)
  29
  30 (defcustom chess-database-modules '(chess-scid chess-file)
  31   "List of database modules to try when `chess-database-open' is called."
  32   :type '(repeat (symbol :tag "Module"))
  33   :group 'chess-database)
  34
  35 (defvar chess-database-handler nil)
  36
  37 (make-variable-buffer-local 'chess-database-handler)
  38
  39 (chess-message-catalog 'english
  40   '((no-such-database . "There is no such chess database module '%s'")))
  41
  42 (defun chess-database-do-open (module file)
  43   "Returns the opened database object, or nil."
  44   (when (require module nil t)
  45     (let* ((name (symbol-name module))
  46            (handler (intern-soft (concat name "-handler"))))
  47       (unless handler
  48         (chess-error 'no-such-database name))
  49       (let ((buffer (funcall handler 'open file)))
  50         (when buffer
  51           (with-current-buffer buffer
  52             (setq chess-database-handler handler)
  53             (add-hook 'kill-buffer-hook 'chess-database-close nil t)
  54             (add-hook 'after-revert-hook 'chess-database-rescan nil t)
  55             (current-buffer)))))))
  56
  57 (defun chess-database-open (file &optional module)
  58   "Returns the opened database object, or nil."
  59   (if module
  60       (chess-database-do-open module file)
  61     (let (result)
  62       (setq module chess-database-modules)
  63       (while module
  64         (if (setq result (chess-database-do-open (car module) file))
  65             (setq module nil)
  66           (setq module (cdr module))))
  67       result)))
  68
  69 (defsubst chess-database-command (database event &rest args)
  70   (with-current-buffer database
  71     (apply chess-database-handler event args)))
  72
  73 (defun chess-database-close (&optional database)
  74   (let ((buf (or database (current-buffer))))
  75     (when (buffer-live-p buf)
  76       (with-current-buffer buf
  77         (remove-hook 'kill-buffer-hook 'chess-database-close t))
  78       (chess-database-save buf)
  79       (chess-database-command buf 'close)
  80       (kill-buffer buf))))
  81
  82 (defun chess-database-save (database)
  83   (chess-database-command database 'save))
  84
  85 (defun chess-database-rescan (&optional database)
  86   (chess-database-command database 'rescan))
  87
  88 (defun chess-database-count (database)
  89   (chess-database-command database 'count))
  90
  91 (defun chess-database-read-only-p (database)
  92   "Return non-nil if DATABASE is read only."
  93   (chess-database-command database 'read-only-p))
  94
  95 (defun chess-database-filename (database)
  96   "Return the filename of an already opened DATABASE."
  97   (chess-database-command database 'filename))
  98
  99 (defun chess-database-read (database index)
 100   "Return from DATABASE the chess game object at INDEX."
 101   (chess-database-command database 'read index))
 102
 103 (defun chess-database-write (database game)
 104   (chess-database-command database 'write game))
 105
 106 (defun chess-database-replace (database game &optional index)
 107   (chess-database-command database 'replace game index))
 108
 109 (defun chess-database-query (database &rest terms)
 110   "Run a query on DATABASE.
 111 TERMS is partly dependent on the chess-database module in use.
 112 chess-scid:
 113  tree-search GAME: Perform a tree search on the last position of GAME."
 114   (apply 'chess-database-command database 'query terms))
 115
 116 (provide 'chess-database)
 117
 118 ;;; chess-database.el ends here