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

   1 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
   2 ;;
   3 ;; A game database that stores PGN format games in a single file.
   4 ;;
   5 ;; This is basically what you expect from a file ending in .pgn.
   6 ;;
   7
   8 (defvar chess-file-locations)
   9
  10 (make-variable-buffer-local 'chess-file-locations)
  11
  12 (defun chess-file-handler (event &rest args)
  13   (cond
  14    ((eq event 'open)
  15     (with-current-buffer (find-file-noselect (car args))
  16       (when (or (string-match "\\.pgn\\'" (car args))
  17                 (save-excursion
  18                   (re-search-forward "^\\[Event" nil t)))
  19         (chess-file-handler 'rescan)
  20         (current-buffer))))
  21
  22    ((eq event 'rescan)
  23     (save-excursion
  24       (goto-char (point-min))
  25       (setq chess-file-locations nil)
  26       (while (re-search-forward "^\\[Event " nil t)
  27         (goto-char (match-beginning 0))
  28         (push (point) chess-file-locations)
  29         (forward-char 1))
  30       (setq chess-file-locations (nreverse chess-file-locations))))
  31
  32    ((eq event 'save)
  33     (save-buffer))
  34
  35    ((eq event 'count)
  36     (length chess-file-locations))
  37
  38    ((eq event 'read)
  39     (let ((index (car args)) game)
  40       (when (and (>= index 0)
  41                  (< index (chess-file-handler 'count)))
  42         (goto-char (nth index chess-file-locations))
  43         (when (setq game (chess-pgn-to-game))
  44           (chess-game-set-data game 'database (current-buffer))
  45           (chess-game-set-data game 'database-index index)
  46           (chess-game-set-data game 'database-count
  47                                (chess-file-handler 'count))
  48           game))))
  49
  50    ((eq event 'write)
  51     (goto-char (point-max))
  52     (while (memq (char-before) '(?  ?\t ?\n ?\r))
  53       (delete-backward-char 1))
  54     (insert ?\n ?\n)
  55     (push (point) chess-file-locations)
  56     (chess-game-to-pgn (car args))
  57     (1- (chess-file-handler 'count)))
  58
  59    ((eq event 'replace)
  60     (let ((index (or (cadr args)
  61                      (chess-game-data (car args) 'database-index)))
  62           (count (chess-file-handler 'count)))
  63       (when (and (>= index 0)
  64                  (< index count))
  65         (goto-char (nth index chess-file-locations))
  66         (delete-region (point) (if (= (1+ index) count)
  67                                    (point-max)
  68                                  (nth (1+ index) chess-file-locations)))
  69         (chess-game-to-pgn (car args))
  70         (insert ?\n))))))
  71
  72 (provide 'chess-file)
  73
  74 ;;; chess-file.el ends here