lisp/play/solitaire.el

   1 ;;; solitaire.el --- game of solitaire in Emacs Lisp
   2
   3 ;; Copyright (C) 1994 Free Software Foundation, Inc.
   4
   5 ;; Author: Jan Schormann <Jan.Schormann@informatik.uni-oldenburg.de>
   6 ;; Created: Fri afternoon, Jun  3,  1994
   7 ;; Keywords: games
   8
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software; you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation; either version 2, or (at your option)
  14 ;; any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs; see the file COPYING.  If not, write to
  23 ;; the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  24 ;; Boston, MA 02111-1307, USA.
  25
  26 ;;; Commentary:
  27
  28 ;; This mode is for playing a well-known game of solitaire
  29 ;; in which you jump pegs across other pegs.
  30
  31 ;; The game itself is somehow self-explanatory.  Read the help text to
  32 ;; solitaire, and try it.
  33
  34 ;;; Code:
  35
  36 (defgroup solitaire nil
  37   "Game of solitaire."
  38   :prefix "solitaire-"
  39   :group 'games)
  40
  41 (defvar solitaire-mode-map nil
  42   "Keymap for playing solitaire.")
  43
  44 (defcustom solitaire-mode-hook nil
  45   "Hook to run upon entry to solitaire."
  46   :type 'hook
  47   :group 'solitaire)
  48
  49 (if solitaire-mode-map
  50     ()
  51   (setq solitaire-mode-map (make-sparse-keymap))
  52   (suppress-keymap solitaire-mode-map t)
  53   (define-key solitaire-mode-map "\C-f" 'solitaire-right)
  54   (define-key solitaire-mode-map "\C-b" 'solitaire-left)
  55   (define-key solitaire-mode-map "\C-p" 'solitaire-up)
  56   (define-key solitaire-mode-map "\C-n" 'solitaire-down)
  57   (define-key solitaire-mode-map [return] 'solitaire-move)
  58   (substitute-key-definition 'undo 'solitaire-undo
  59                              solitaire-mode-map global-map)
  60   (define-key solitaire-mode-map " " 'solitaire-do-check)
  61   (define-key solitaire-mode-map "q" 'quit-window)
  62
  63   (define-key solitaire-mode-map [right] 'solitaire-right)
  64   (define-key solitaire-mode-map [left] 'solitaire-left)
  65   (define-key solitaire-mode-map [up] 'solitaire-up)
  66   (define-key solitaire-mode-map [down] 'solitaire-down)
  67
  68   (define-key solitaire-mode-map [S-right] 'solitaire-move-right)
  69   (define-key solitaire-mode-map [S-left]  'solitaire-move-left)
  70   (define-key solitaire-mode-map [S-up]    'solitaire-move-up)
  71   (define-key solitaire-mode-map [S-down]  'solitaire-move-down)
  72
  73   (define-key solitaire-mode-map [kp-6] 'solitaire-right)
  74   (define-key solitaire-mode-map [kp-4] 'solitaire-left)
  75   (define-key solitaire-mode-map [kp-8] 'solitaire-up)
  76   (define-key solitaire-mode-map [kp-2] 'solitaire-down)
  77   (define-key solitaire-mode-map [kp-5] 'solitaire-center-point)
  78
  79   (define-key solitaire-mode-map [S-kp-6] 'solitaire-move-right)
  80   (define-key solitaire-mode-map [S-kp-4] 'solitaire-move-left)
  81   (define-key solitaire-mode-map [S-kp-8] 'solitaire-move-up)
  82   (define-key solitaire-mode-map [S-kp-2] 'solitaire-move-down)
  83
  84   (define-key solitaire-mode-map [kp-enter] 'solitaire-move)
  85   (define-key solitaire-mode-map [kp-0] 'solitaire-undo)
  86
  87   ;; spoil it with s ;)
  88   (define-key solitaire-mode-map [?s] 'solitaire-solve)
  89
  90   ;;  (define-key solitaire-mode-map [kp-0] 'solitaire-hint) - Not yet provided ;)
  91   )
  92
  93 ;; Solitaire mode is suitable only for specially formatted data.
  94 (put 'solitaire-mode 'mode-class 'special)
  95
  96 (defun solitaire-mode ()
  97   "Major mode for playing solitaire.
  98 To learn how to play solitaire, see the documentation for function
  99 `solitaire'.
 100 \\<solitaire-mode-map>
 101 The usual mnemonic keys move the cursor around the board; in addition,
 102 \\[solitaire-move] is a prefix character for actually moving a stone on the board."
 103   (interactive)
 104   (kill-all-local-variables)
 105   (use-local-map solitaire-mode-map)
 106   (setq truncate-lines t)
 107   (setq major-mode 'solitaire-mode)
 108   (setq mode-name "Solitaire")
 109   (run-hooks 'solitaire-mode-hook))
 110
 111 (defvar solitaire-stones 0
 112   "Counter for the stones that are still there.")
 113
 114 (defvar solitaire-center nil
 115   "Center of the board.")
 116
 117 (defvar solitaire-start nil
 118   "Upper left corner of the board.")
 119
 120 (defvar solitaire-start-x nil)
 121 (defvar solitaire-start-y nil)
 122
 123 (defvar solitaire-end nil
 124   "Lower right corner of the board.")
 125
 126 (defvar solitaire-end-x nil)
 127 (defvar solitaire-end-y nil)
 128
 129 (defcustom solitaire-auto-eval t
 130   "*Non-nil means check for possible moves after each major change.
 131 This takes a while, so switch this on if you like to be informed when
 132 the game is over, or off, if you are working on a slow machine."
 133   :type 'boolean
 134   :group 'solitaire)
 135
 136 (defconst solitaire-valid-directions
 137   '(solitaire-left solitaire-right solitaire-up solitaire-down))
 138
 139 ;;;###autoload
 140 (defun solitaire (arg)
 141   "Play Solitaire.
 142
 143 To play Solitaire, type \\[solitaire].
 144 \\<solitaire-mode-map>
 145 Move around the board using the cursor keys.
 146 Move stones using \\[solitaire-move] followed by a direction key.
 147 Undo moves using \\[solitaire-undo].
 148 Check for possible moves using \\[solitaire-do-check].
 149 \(The variable `solitaire-auto-eval' controls whether to automatically
 150 check after each move or undo)
 151
 152 What is Solitaire?
 153
 154 I don't know who invented this game, but it seems to be rather old and
 155 its origin seems to be northern Africa.  Here's how to play:
 156 Initially, the board will look similar to this:
 157
 158         Le Solitaire
 159         ============
 160
 161                 o   o   o
 162
 163                 o   o   o
 164
 165         o   o   o   o   o   o   o
 166
 167         o   o   o   .   o   o   o
 168
 169         o   o   o   o   o   o   o
 170
 171                 o   o   o
 172
 173                 o   o   o
 174
 175 Let's call the o's stones and the .'s holes.  One stone fits into one
 176 hole.  As you can see, all holes but one are occupied by stones.  The
 177 aim of the game is to get rid of all but one stone, leaving that last
 178 one in the middle of the board if you're cool.
 179
 180 A stone can be moved if there is another stone next to it, and a hole
 181 after that one.  Thus there must be three fields in a row, either
 182 horizontally or vertically, up, down, left or right, which look like
 183 this:  o  o  .
 184
 185 Then the first stone is moved to the hole, jumping over the second,
 186 which therefore is taken away.  The above thus `evaluates' to:  .  .  o
 187
 188 That's all.  Here's the board after two moves:
 189
 190                 o   o   o
 191
 192                 .   o   o
 193
 194         o   o   .   o   o   o   o
 195
 196         o   .   o   o   o   o   o
 197
 198         o   o   o   o   o   o   o
 199
 200                 o   o   o
 201
 202                 o   o   o
 203
 204 Pick your favourite shortcuts:
 205
 206 \\{solitaire-mode-map}"
 207
 208   (interactive "P")
 209   (switch-to-buffer "*Solitaire*")
 210   (solitaire-mode)
 211   (setq buffer-read-only t)
 212   (setq solitaire-stones 32)
 213   (solitaire-insert-board)
 214   (solitaire-build-modeline)
 215   (goto-char (point-max))
 216   (setq solitaire-center (search-backward "."))
 217   (setq buffer-undo-list (list (point)))
 218   (set-buffer-modified-p nil))
 219
 220 (defun solitaire-build-modeline ()
 221   (setq mode-line-format
 222         (list "" "---" 'mode-line-buffer-identification
 223               (if (< 1 solitaire-stones)
 224                   (format "--> There are %d stones left <--" solitaire-stones)
 225                 "------")
 226               'global-mode-string "   %[(" 'mode-name 'minor-mode-alist "%n"
 227               ")%]-%-"))
 228   (force-mode-line-update))
 229
 230 (defun solitaire-insert-board ()
 231   (let* ((buffer-read-only nil)
 232          (w (window-width))
 233          (h (window-height))
 234          (hsep (cond ((> w 26) "   ")
 235                      ((> w 20) " ")
 236                      (t "")))
 237          (vsep (cond ((> h 17) "\n\n")
 238                      (t "\n")))
 239          (indent (make-string (/ (- w 7 (* 6 (length hsep))) 2) ?\ )))
 240     (erase-buffer)
 241     (insert (make-string (/ (- h 7 (if (> h 12) 3 0)
 242                                (* 6 (1- (length vsep)))) 2) ?\n))
 243     (if (or (string= vsep "\n\n") (> h 12))
 244         (progn
 245           (insert (format "%sLe Solitaire\n" indent))
 246           (insert (format "%s============\n\n" indent))))
 247     (insert indent)
 248     (setq solitaire-start (point))
 249     (setq solitaire-start-x (current-column))
 250     (setq solitaire-start-y (solitaire-current-line))
 251     (insert (format " %s %so%so%so%s" hsep hsep hsep hsep vsep))
 252     (insert (format "%s %s %so%so%so%s" indent hsep hsep hsep hsep vsep))
 253     (insert (format "%so%so%so%so%so%so%so%s" indent hsep hsep hsep hsep hsep hsep vsep))
 254     (insert (format "%so%so%so%s" indent hsep hsep hsep))
 255     (setq solitaire-center (point))
 256     (insert (format ".%so%so%so%s" hsep hsep hsep vsep))
 257     (insert (format "%so%so%so%so%so%so%so%s" indent hsep hsep hsep hsep hsep hsep vsep))
 258     (insert (format "%s %s %so%so%so%s" indent hsep hsep hsep hsep vsep))
 259     (insert (format "%s %s %so%so%so%s %s " indent hsep hsep hsep hsep hsep hsep))
 260     (setq solitaire-end (point))
 261     (setq solitaire-end-x (current-column))
 262     (setq solitaire-end-y (solitaire-current-line))
 263     ))
 264
 265 (defun solitaire-right ()
 266   (interactive)
 267   (let ((start (point)))
 268     (forward-char)
 269     (while (= ?\  (following-char))
 270       (forward-char))
 271     (if (or  (= 0 (following-char))
 272              (= ?\  (following-char))
 273             (= ?\n (following-char)))
 274         (goto-char start))))
 275
 276 (defun solitaire-left ()
 277   (interactive)
 278   (let ((start (point)))
 279     (backward-char)
 280     (while (= ?\  (following-char))
 281       (backward-char))
 282     (if (or  (= 0 (preceding-char))
 283              (= ?\  (following-char))
 284             (= ?\n (following-char)))
 285         (goto-char start))))
 286
 287 (defun solitaire-up ()
 288   (interactive)
 289   (let ((start (point))
 290         (c (current-column)))
 291     (forward-line -1)
 292     (move-to-column c)
 293     (while (and (= ?\n (following-char))
 294                 (forward-line -1)
 295                 (move-to-column c)
 296                 (not (bolp))))
 297     (if (or (= 0 (preceding-char))
 298             (= ?\  (following-char))
 299             (= ?\= (following-char))
 300             (= ?\n (following-char)))
 301         (goto-char start)
 302         )))
 303
 304 (defun solitaire-down ()
 305   (interactive)
 306   (let ((start (point))
 307         (c (current-column)))
 308     (forward-line 1)
 309     (move-to-column c)
 310     (while (and (= ?\n (following-char))
 311                 (forward-line 1)
 312                 (move-to-column c)
 313                 (not (eolp))))
 314     (if (or (= 0 (following-char))
 315             (= ?\  (following-char))
 316             (= ?\n (following-char)))
 317         (goto-char start))))
 318
 319 (defun solitaire-center-point ()
 320   (interactive)
 321   (goto-char solitaire-center))
 322
 323 (defun solitaire-move-right () (interactive) (solitaire-move '[right]))
 324 (defun solitaire-move-left () (interactive) (solitaire-move '[left]))
 325 (defun solitaire-move-up () (interactive) (solitaire-move '[up]))
 326 (defun solitaire-move-down () (interactive) (solitaire-move '[down]))
 327
 328 (defun solitaire-possible-move (movesymbol)
 329   "Check if a move is possible from current point in the specified direction.
 330 MOVESYMBOL specifies the direction.
 331 Returns either a string, indicating cause of contraindication, or a
 332 list containing three numbers: starting field, skipped field (from
 333 which a stone will be taken away) and target."
 334
 335   (save-excursion
 336     (if (memq movesymbol solitaire-valid-directions)
 337         (let ((start (point))
 338               (skip (progn (funcall movesymbol) (point)))
 339               (target (progn (funcall movesymbol) (point))))
 340           (if (= skip target)
 341               "Off Board!"
 342             (if (or (/= ?o (char-after start))
 343                     (/= ?o (char-after skip))
 344                     (/= ?. (char-after target)))
 345                 "Wrong move!"
 346               (list start skip target))))
 347       "Not a valid direction")))
 348
 349 (defun solitaire-move (dir)
 350   "Pseudo-prefix command to move a stone in Solitaire."
 351   (interactive "kMove where? ")
 352   (let* ((class (solitaire-possible-move (lookup-key solitaire-mode-map dir)))
 353          (buffer-read-only nil))
 354     (if (stringp class)
 355         (error class)
 356       (let ((start (car class))
 357             (skip (car (cdr class)))
 358             (target (car (cdr (cdr class)))))
 359         (goto-char start)
 360         (delete-char 1)
 361         (insert ?.)
 362         (goto-char skip)
 363         (delete-char 1)
 364         (insert ?.)
 365         (goto-char target)
 366         (delete-char 1)
 367         (insert ?o)
 368         (goto-char target)
 369         (setq solitaire-stones (1- solitaire-stones))
 370         (solitaire-build-modeline)
 371         (if solitaire-auto-eval (solitaire-do-check))))))
 372
 373 (defun solitaire-undo (arg)
 374   "Undo a move in Solitaire."
 375   (interactive "P")
 376   (let ((buffer-read-only nil))
 377     (undo arg))
 378   (save-excursion
 379     (setq solitaire-stones
 380           (let ((count 0))
 381             (goto-char solitaire-end)
 382             (while (search-backward "o" solitaire-start 'done)
 383               (and (>= (current-column) solitaire-start-x)
 384                    (<= (current-column) solitaire-end-x)
 385                    (>= (solitaire-current-line) solitaire-start-y)
 386                    (<= (solitaire-current-line) solitaire-end-y)
 387                    (setq count (1+ count))))
 388             count)))
 389   (solitaire-build-modeline)
 390   (if solitaire-auto-eval (solitaire-do-check)))
 391
 392 (defun solitaire-check ()
 393   (save-excursion
 394     (if (= 1 solitaire-stones)
 395         0
 396       (goto-char solitaire-end)
 397       (let ((count 0))
 398         (while (search-backward "o" solitaire-start 'done)
 399           (and (>= (current-column) solitaire-start-x)
 400                (<= (current-column) solitaire-end-x)
 401                (>= (solitaire-current-line) solitaire-start-y)
 402                (<= (solitaire-current-line) solitaire-end-y)
 403                (mapcar
 404                 (lambda (movesymbol)
 405                   (if (listp (solitaire-possible-move movesymbol))
 406                       (setq count (1+ count))))
 407                 solitaire-valid-directions)))
 408         count))))
 409
 410 (defun solitaire-do-check (&optional arg)
 411   "Check for any possible moves in Solitaire."
 412   (interactive "P")
 413   (let ((moves (solitaire-check)))
 414     (cond ((= 1 solitaire-stones)
 415            (message "Yeah! You made it! Only the King is left!"))
 416           ((zerop moves)
 417            (message "Sorry, no more possible moves."))
 418           ((= 1 moves)
 419            (message "There is one possible move."))
 420           (t (message "There are %d possible moves." moves)))))
 421
 422 (defun solitaire-current-line ()
 423   "Return the vertical position of point.
 424 Seen in info on text lines."
 425   (+ (count-lines (point-min) (point))
 426      (if (= (current-column) 0) 1 0)
 427      -1))
 428
 429 ;; And here's the spoiler:)
 430 (defun solitaire-solve ()
 431   "Spoil solitaire by solving the game for you - nearly ...
 432 ... stops with five stones left ;)"
 433   (interactive)
 434   (let ((allmoves [up up S-down up left left S-right up up left S-down
 435                       up up right right S-left down down down S-up up
 436                       S-down down down down S-up left left down
 437                       S-right left left up up S-down right right right
 438                       S-left left S-right right right right S-left
 439                       right down down S-up down down left left S-right
 440                       up up up S-down down S-up up up up S-down up
 441                       right right S-left down right right down S-up
 442                       left left left S-right right S-left down down
 443                       left S-right S-up S-left S-left S-down S-right
 444                       up S-right left left])
 445         ;; down down S-up left S-right
 446         ;; right S-left
 447         (solitaire-auto-eval nil))
 448     (solitaire-center-point)
 449     (mapcar (lambda (op)
 450               (if (memq op '(S-left S-right S-up S-down))
 451                   (sit-for 0.2))
 452               (execute-kbd-macro (vector op))
 453               (if (memq op '(S-left S-right S-up S-down))
 454                   (sit-for 0.4)))
 455             allmoves))
 456   (solitaire-do-check))
 457
 458 (provide 'solitaire)
 459
 460 ;;; solitaire.el ends here