lisp/info.el

   1 ;;; info.el --- info package for Emacs.
   2
   3 ;; Copyright (C) 1985, 1986, 1992, 1993 Free Software Foundation, Inc.
   4
   5 ;; Maintainer: FSF
   6 ;; Keywords: help
   7
   8 ;; This file is part of GNU Emacs.
   9
  10 ;; GNU Emacs is free software; you can redistribute it and/or modify
  11 ;; it under the terms of the GNU General Public License as published by
  12 ;; the Free Software Foundation; either version 2, or (at your option)
  13 ;; any later version.
  14
  15 ;; GNU Emacs is distributed in the hope that it will be useful,
  16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ;; GNU General Public License for more details.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs; see the file COPYING.  If not, write to
  22 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  23
  24 ;;; Commentary:
  25
  26 ;;; Note that nowadays we expect info files to be made using makeinfo.
  27
  28 ;;; Code:
  29
  30 (defvar Info-history nil
  31   "List of info nodes user has visited.
  32 Each element of list is a list (FILENAME NODENAME BUFFERPOS).")
  33
  34 (defvar Info-enable-edit nil
  35   "*Non-nil means the \\<Info-mode-map>\\[Info-edit] command in Info can edit the current node.
  36 This is convenient if you want to write info files by hand.
  37 However, we recommend that you not do this.
  38 It is better to write a Texinfo file and generate the Info file from that,
  39 because that gives you a printed manual as well.")
  40
  41 (defvar Info-enable-active-nodes t
  42   "Non-nil allows Info to execute Lisp code associated with nodes.
  43 The Lisp code is executed when the node is selected.")
  44
  45 (defvar Info-default-directory-list nil
  46   "List of default directories to search for Info documentation files.
  47 This value is used as the default for `Info-directory-list'.  It is set
  48 in paths.el.")
  49
  50 (defvar Info-fontify t
  51   "*Non-nil enables highlighting and fonts in Info nodes.")
  52
  53 (defvar Info-directory-list
  54   (let ((path (getenv "INFOPATH"))
  55         (sibling (expand-file-name "../info/" (invocation-directory))))
  56     (if path
  57         (let ((list nil)
  58               idx)
  59           (while (> (length path) 0)
  60             (setq idx (or (string-match ":" path) (length path))
  61                   list (cons (substring path 0 idx) list)
  62                   path (substring path (min (1+ idx)
  63                                             (length path)))))
  64           (nreverse list))
  65       (if (or (member sibling Info-default-directory-list)
  66               (not (file-exists-p sibling)))
  67           Info-default-directory-list
  68         (reverse (cons sibling (cdr (reverse Info-default-directory-list)))))))
  69   "List of directories to search for Info documentation files.
  70 nil means not yet initialized.  In this case, Info uses the environment
  71 variable INFOPATH to initialize it, or `Info-default-directory-list'
  72 if there is no INFOPATH variable in the environment.")
  73
  74 (defvar Info-current-file nil
  75   "Info file that Info is now looking at, or nil.")
  76
  77 (defvar Info-current-subfile nil
  78   "Info subfile that is actually in the *info* buffer now,
  79 or nil if current info file is not split into subfiles.")
  80
  81 (defvar Info-current-node nil
  82   "Name of node that Info is now looking at, or nil.")
  83
  84 (defvar Info-tag-table-marker (make-marker)
  85   "Marker pointing at beginning of current Info file's tag table.
  86 Marker points nowhere if file has no tag table.")
  87
  88 (defvar Info-current-file-completions nil
  89   "Cached completion list for current Info file.")
  90
  91 (defvar Info-index-alternatives nil
  92   "List of possible matches for last Info-index command.")
  93
  94 (defvar Info-standalone nil
  95   "Non-nil if Emacs was started solely as an Info browser.")
  96
  97 (defvar Info-suffix-list '( (".info.Z"  . "uncompress")
  98                             (".info.Y"  . "unyabba")
  99                             (".info.gz" . "gunzip")
 100                             (".info.z"  . "gunzip")
 101                             (".info"    . nil)
 102                             (".Z"       . "uncompress")
 103                             (".Y"       . "unyabba")
 104                             (".gz"      . "gunzip")
 105                             (".z"       . "gunzip")
 106                             (""         . nil))
 107   "List of file name suffixes and associated decoding commands.
 108 Each entry should be (SUFFIX . STRING); the file is given to
 109 the command as standard input.  If STRING is nil, no decoding is done.
 110 Because the SUFFIXes are tried in order, the empty string should
 111 be last in the list.")
 112
 113 (defun info-insert-file-contents (filename &optional visit)
 114   "Insert the contents of an info file in the current buffer.
 115 Do the right thing if the file has been compressed or zipped."
 116   (let ((tail Info-suffix-list)
 117         fullname decoder)
 118     (if (file-exists-p filename)
 119         (progn
 120           (while (and tail
 121                       (not (string-match
 122                             (concat (regexp-quote (car (car tail))) "$")
 123                             filename)))
 124             (setq tail (cdr tail)))
 125           (setq fullname filename
 126                 decoder (cdr (car tail))))
 127       (while (and tail
 128                   (not (file-exists-p (concat filename (car (car tail))))))
 129         (setq tail (cdr tail)))
 130       (setq fullname (concat filename (car (car tail)))
 131             decoder (cdr (car tail)))
 132       (or tail
 133           (error "Can't find %s or any compressed version of it!" filename)))
 134     (insert-file-contents fullname visit)
 135     (if decoder
 136         (let ((buffer-read-only nil))
 137           (shell-command-on-region (point-min) (point-max) decoder t)))))
 138
 139 ;;;###autoload
 140 (defun info (&optional file)
 141   "Enter Info, the documentation browser.
 142 Optional argument FILE specifies the file to examine;
 143 the default is the top-level directory of Info.
 144
 145 In interactive use, a prefix argument directs this command
 146 to read a file name from the minibuffer."
 147   (interactive (if current-prefix-arg
 148                    (list (read-file-name "Info file name: " nil nil t))))
 149   (if file
 150       (Info-goto-node (concat "(" file ")"))
 151     (if (get-buffer "*info*")
 152         (switch-to-buffer "*info*")
 153       (Info-directory))))
 154
 155 ;;;###autoload
 156 (defun info-standalone ()
 157   "Run Emacs as a standalone Info reader.
 158 Usage:  emacs -f info-standalone [filename]
 159 In standalone mode, \\<Info-mode-map>\\[Info-exit] exits Emacs itself."
 160   (setq Info-standalone t)
 161   (if (and command-line-args-left
 162            (not (string-match "^-" (car command-line-args-left))))
 163       (condition-case err
 164           (progn
 165             (info (car command-line-args-left))
 166             (setq command-line-args-left (cdr command-line-args-left)))
 167         (error (send-string-to-terminal
 168                 (format "%s\n" (if (eq (car-safe err) 'error)
 169                                    (nth 1 err) err)))
 170                (save-buffers-kill-emacs)))
 171     (info)))
 172
 173 ;; Go to an info node specified as separate filename and nodename.
 174 ;; no-going-back is non-nil if recovering from an error in this function;
 175 ;; it says do not attempt further (recursive) error recovery.
 176 (defun Info-find-node (filename nodename &optional no-going-back)
 177   ;; Convert filename to lower case if not found as specified.
 178   ;; Expand it.
 179   (if filename
 180       (let (temp temp-downcase found)
 181         (setq filename (substitute-in-file-name filename))
 182         (if (string= (downcase (file-name-nondirectory filename)) "dir")
 183             (setq found t)
 184           (let ((dirs (if (string-match "^\\./" filename)
 185                           ;; If specified name starts with `./'
 186                           ;; then just try current directory.
 187                           '("./")
 188                         Info-directory-list)))
 189             ;; Search the directory list for file FILENAME.
 190             (while (and dirs (not found))
 191               (setq temp (expand-file-name filename (car dirs)))
 192               (setq temp-downcase
 193                     (expand-file-name (downcase filename) (car dirs)))
 194               ;; Try several variants of specified name.
 195               (catch 'foundit
 196                 (mapcar
 197                  (function
 198                   (lambda (x)
 199                     (if (file-exists-p (concat temp (car x)))
 200                         (progn
 201                           (setq found temp)
 202                           (throw 'foundit nil)))
 203                     (if (file-exists-p (concat temp-downcase (car x)))
 204                         (progn
 205                           (setq found temp-downcase)
 206                           (throw 'foundit nil)))))
 207                  Info-suffix-list))
 208               (setq dirs (cdr dirs)))))
 209         (if found
 210             (setq filename found)
 211           (error "Info file %s does not exist" filename))))
 212   ;; Record the node we are leaving.
 213   (if (and Info-current-file (not no-going-back))
 214       (setq Info-history
 215             (cons (list Info-current-file Info-current-node (point))
 216                   Info-history)))
 217   ;; Go into info buffer.
 218   (switch-to-buffer "*info*")
 219   (buffer-disable-undo (current-buffer))
 220   (or (eq major-mode 'Info-mode)
 221       (Info-mode))
 222   (widen)
 223   (setq Info-current-node nil)
 224   (unwind-protect
 225       (progn
 226         ;; Switch files if necessary
 227         (or (null filename)
 228             (equal Info-current-file filename)
 229             (let ((buffer-read-only nil))
 230               (setq Info-current-file nil
 231                     Info-current-subfile nil
 232                     Info-current-file-completions nil
 233                     Info-index-alternatives nil
 234                     buffer-file-name nil)
 235               (erase-buffer)
 236               (if (eq filename t)
 237                   (Info-insert-dir)
 238                 (info-insert-file-contents filename t)
 239                 (setq default-directory (file-name-directory filename)))
 240               (set-buffer-modified-p nil)
 241               ;; See whether file has a tag table.  Record the location if yes.
 242               (set-marker Info-tag-table-marker nil)
 243               (goto-char (point-max))
 244               (forward-line -8)
 245               (or (equal nodename "*")
 246                   (not (search-forward "\^_\nEnd tag table\n" nil t))
 247                   (let (pos)
 248                     ;; We have a tag table.  Find its beginning.
 249                     ;; Is this an indirect file?
 250                     (search-backward "\nTag table:\n")
 251                     (setq pos (point))
 252                     (if (save-excursion
 253                           (forward-line 2)
 254                           (looking-at "(Indirect)\n"))
 255                         ;; It is indirect.  Copy it to another buffer
 256                         ;; and record that the tag table is in that buffer.
 257                         (save-excursion
 258                           (let ((buf (current-buffer)))
 259                             (set-buffer (get-buffer-create " *info tag table*"))
 260                             (buffer-disable-undo (current-buffer))
 261                             (setq case-fold-search t)
 262                             (erase-buffer)
 263                             (insert-buffer-substring buf)
 264                             (set-marker Info-tag-table-marker
 265                                         (match-end 0))))
 266                       (set-marker Info-tag-table-marker pos))))
 267               (setq Info-current-file
 268                     (if (eq filename t) "dir"
 269                       (file-name-sans-versions buffer-file-name)))))
 270         (if (equal nodename "*")
 271             (progn (setq Info-current-node nodename)
 272                    (Info-set-mode-line))
 273           ;; Search file for a suitable node.
 274           (let ((guesspos (point-min))
 275                 (regexp (concat "Node: *" (regexp-quote nodename) " *[,\t\n\177]")))
 276             ;; First get advice from tag table if file has one.
 277             ;; Also, if this is an indirect info file,
 278             ;; read the proper subfile into this buffer.
 279             (if (marker-position Info-tag-table-marker)
 280                 (save-excursion
 281                   (set-buffer (marker-buffer Info-tag-table-marker))
 282                   (goto-char Info-tag-table-marker)
 283                   (if (re-search-forward regexp nil t)
 284                       (progn
 285                         (setq guesspos (read (current-buffer)))
 286                         ;; If this is an indirect file,
 287                         ;; determine which file really holds this node
 288                         ;; and read it in.
 289                         (if (not (eq (current-buffer) (get-buffer "*info*")))
 290                             (setq guesspos
 291                                   (Info-read-subfile guesspos))))
 292                     (error "No such node: \"%s\"" nodename))))
 293             (goto-char (max (point-min) (- guesspos 1000)))
 294             ;; Now search from our advised position (or from beg of buffer)
 295             ;; to find the actual node.
 296             (catch 'foo
 297               (while (search-forward "\n\^_" nil t)
 298                 (forward-line 1)
 299                 (let ((beg (point)))
 300                   (forward-line 1)
 301                   (if (re-search-backward regexp beg t)
 302                       (throw 'foo t))))
 303               (error "No such node: %s" nodename)))
 304           (Info-select-node)))
 305     ;; If we did not finish finding the specified node,
 306     ;; go back to the previous one.
 307     (or Info-current-node no-going-back
 308         (let ((hist (car Info-history)))
 309           (setq Info-history (cdr Info-history))
 310           (Info-find-node (nth 0 hist) (nth 1 hist) t)
 311           (goto-char (nth 2 hist)))))
 312   (goto-char (point-min)))
 313
 314 ;; Cache the contents of the (virtual) dir file, once we have merged
 315 ;; it for the first time, so we can save time subsequently.
 316 (defvar Info-dir-contents nil)
 317
 318 ;; Cache for the directory we decided to use for the default-directory
 319 ;; of the merged dir text.
 320 (defvar Info-dir-contents-directory nil)
 321
 322 ;; Record the file attributes of all the files from which we
 323 ;; constructed Info-dir-contents.
 324 (defvar Info-dir-file-attributes nil)
 325
 326 ;; Construct the Info directory node by merging the files named `dir'
 327 ;; from various directories.  Set the *info* buffer's
 328 ;; default-directory to the first directory we actually get any text
 329 ;; from.
 330 (defun Info-insert-dir ()
 331   (if (and Info-dir-contents Info-dir-file-attributes
 332            ;; Verify that none of the files we used has changed
 333            ;; since we used it.
 334            (eval (cons 'and
 335                        (mapcar '(lambda (elt)
 336                                   (equal (cdr elt)
 337                                          (file-attributes (car elt))))
 338                                Info-dir-file-attributes))))
 339       (insert Info-dir-contents)
 340     (let ((dirs Info-directory-list)
 341           buffers buffer others nodes dirs-done)
 342
 343       ;; Search the directory list for the directory file.
 344       (while dirs
 345         (let ((truename (file-truename (expand-file-name (car dirs)))))
 346           (or (member truename dirs-done)
 347               (member (directory-file-name truename) dirs-done)
 348               ;; Try several variants of specified name.
 349               ;; Try upcasing, appending `.info', or both.
 350               (let* (temp
 351                      (buffer
 352                       (cond
 353                        ((progn (setq temp (expand-file-name "DIR" (car dirs)))
 354                                (file-exists-p temp))
 355                         (find-file-noselect temp))
 356                        ((progn (setq temp (expand-file-name "dir" (car dirs)))
 357                                (file-exists-p temp))
 358                         (find-file-noselect temp))
 359                        ((progn (setq temp (expand-file-name "DIR.INFO" (car dirs)))
 360                                (file-exists-p temp))
 361                         (find-file-noselect temp))
 362                        ((progn (setq temp (expand-file-name "dir.info" (car dirs)))
 363                                (file-exists-p temp))
 364                         (find-file-noselect temp)))))
 365                 (setq dirs-done
 366                       (cons truename
 367                             (cons (directory-file-name truename)
 368                                   dirs-done)))
 369                 (if buffer (setq buffers (cons buffer buffers)
 370                                  Info-dir-file-attributes
 371                                  (cons (cons (buffer-file-name buffer)
 372                                              (file-attributes (buffer-file-name buffer)))
 373                                        Info-dir-file-attributes))))))
 374         (setq dirs (cdr dirs)))
 375
 376       ;; Distinguish the dir file that comes with Emacs from all the
 377       ;; others.  Yes, that is really what this is supposed to do.
 378       ;; If it doesn't work, fix it.
 379       (setq buffer (car buffers)
 380             others (cdr buffers))
 381
 382       ;; Insert the entire original dir file as a start; use its
 383       ;; default directory as the default directory for the whole
 384       ;; concatenation.
 385       (insert-buffer buffer)
 386       (setq Info-dir-contents-directory (save-excursion
 387                                           (set-buffer buffer)
 388                                           default-directory))
 389
 390       ;; Look at each of the other buffers one by one.
 391       (while others
 392         (let ((other (car others)))
 393           ;; In each, find all the menus.
 394           (save-excursion
 395             (set-buffer other)
 396             (goto-char (point-min))
 397             ;; Find each menu, and add an elt to NODES for it.
 398             (while (re-search-forward "^\\* Menu:" nil t)
 399               (let (beg nodename end)
 400                 (forward-line 1)
 401                 (setq beg (point))
 402                 (search-backward "\n\^_")
 403                 (search-forward "Node: ")
 404                 (setq nodename (Info-following-node-name))
 405                 (search-forward "\n\^_" nil 'move)
 406                 (beginning-of-line)
 407                 (setq end (point))
 408                 (setq nodes (cons (list nodename other beg end) nodes))))))
 409         (setq others (cdr others)))
 410       ;; Add to the main menu a menu item for each other node.
 411       (re-search-forward "^\\* Menu:")
 412       (forward-line 1)
 413       (let ((menu-items '("top"))
 414             (nodes nodes)
 415             (case-fold-search t)
 416             (end (save-excursion (search-forward "\^_" nil t) (point))))
 417         (while nodes
 418           (let ((nodename (car (car nodes))))
 419             (save-excursion
 420               (or (member (downcase nodename) menu-items)
 421                   (re-search-forward (concat "^\\* "
 422                                              (regexp-quote nodename)
 423                                              "::")
 424                                      end t)
 425                   (progn
 426                     (insert "* " nodename "::" "\n")
 427                     (setq menu-items (cons nodename menu-items))))))
 428           (setq nodes (cdr nodes))))
 429       ;; Now take each node of each of the other buffers
 430       ;; and merge it into the main buffer.
 431       (while nodes
 432         (let ((nodename (car (car nodes))))
 433           (goto-char (point-min))
 434           ;; Find the like-named node in the main buffer.
 435           (if (re-search-forward (concat "\n\^_.*\n.*Node: "
 436                                          (regexp-quote nodename)
 437                                          "[,\n\t]")
 438                                  nil t)
 439               (progn
 440                 (search-forward "\n\^_" nil 'move)
 441                 (beginning-of-line))
 442             ;; If none exists, add one.
 443             (goto-char (point-max))
 444             (insert "\^_\nFile: dir\tnode: " nodename "\n\n* Menu:\n\n"))
 445           ;; Merge the text from the other buffer's menu
 446           ;; into the menu in the like-named node in the main buffer.
 447           (apply 'insert-buffer-substring (cdr (car nodes)))
 448           (insert "\n"))
 449         (setq nodes (cdr nodes)))
 450       ;; Kill all the buffers we just made.
 451       (while buffers
 452         (kill-buffer (car buffers))
 453         (setq buffers (cdr buffers))))
 454     (setq Info-dir-contents (buffer-string)))
 455   (setq default-directory Info-dir-contents-directory))
 456
 457 (defun Info-read-subfile (nodepos)
 458   (set-buffer (marker-buffer Info-tag-table-marker))
 459   (goto-char (point-min))
 460   (search-forward "\n\^_")
 461   (let (lastfilepos
 462         lastfilename)
 463     (forward-line 2)
 464     (catch 'foo
 465       (while (not (looking-at "\^_"))
 466         (if (not (eolp))
 467             (let ((beg (point))
 468                   thisfilepos thisfilename)
 469               (search-forward ": ")
 470               (setq thisfilename  (buffer-substring beg (- (point) 2)))
 471               (setq thisfilepos (read (current-buffer)))
 472               ;; read in version 19 stops at the end of number.
 473               ;; Advance to the next line.
 474               (forward-line 1)
 475               (if (> thisfilepos nodepos)
 476                   (throw 'foo t))
 477               (setq lastfilename thisfilename)
 478               (setq lastfilepos thisfilepos))
 479           (forward-line 1))))
 480     (set-buffer (get-buffer "*info*"))
 481     (or (equal Info-current-subfile lastfilename)
 482         (let ((buffer-read-only nil))
 483           (setq buffer-file-name nil)
 484           (widen)
 485           (erase-buffer)
 486           (info-insert-file-contents lastfilename)
 487           (set-buffer-modified-p nil)
 488           (setq Info-current-subfile lastfilename)))
 489     (goto-char (point-min))
 490     (search-forward "\n\^_")
 491     (+ (- nodepos lastfilepos) (point))))
 492
 493 ;; Select the info node that point is in.
 494 (defun Info-select-node ()
 495   (save-excursion
 496    ;; Find beginning of node.
 497    (search-backward "\n\^_")
 498    (forward-line 2)
 499    ;; Get nodename spelled as it is in the node.
 500    (re-search-forward "Node:[ \t]*")
 501    (setq Info-current-node
 502          (buffer-substring (point)
 503                            (progn
 504                             (skip-chars-forward "^,\t\n")
 505                             (point))))
 506    (Info-set-mode-line)
 507    ;; Find the end of it, and narrow.
 508    (beginning-of-line)
 509    (let (active-expression)
 510      (narrow-to-region (point)
 511                        (if (re-search-forward "\n[\^_\f]" nil t)
 512                            (prog1
 513                             (1- (point))
 514                             (if (looking-at "[\n\^_\f]*execute: ")
 515                                 (progn
 516                                   (goto-char (match-end 0))
 517                                   (setq active-expression
 518                                         (read (current-buffer))))))
 519                          (point-max)))
 520      (if Info-enable-active-nodes (eval active-expression))
 521      (if Info-fontify (Info-fontify-node))
 522      (run-hooks 'Info-selection-hook))))
 523
 524 (defun Info-set-mode-line ()
 525   (setq mode-line-buffer-identification
 526         (concat
 527          "Info:  ("
 528          (if Info-current-file
 529              (file-name-nondirectory Info-current-file)
 530            "")
 531          ")"
 532          (or Info-current-node ""))))
 533 \f
 534 ;; Go to an info node specified with a filename-and-nodename string
 535 ;; of the sort that is found in pointers in nodes.
 536
 537 (defun Info-goto-node (nodename)
 538   "Go to info node named NAME.  Give just NODENAME or (FILENAME)NODENAME."
 539   (interactive (list (Info-read-node-name "Goto node: ")))
 540   (let (filename)
 541     (string-match "\\s *\\((\\s *\\([^\t)]*\\)\\s *)\\s *\\|\\)\\(.*\\)"
 542                   nodename)
 543     (setq filename (if (= (match-beginning 1) (match-end 1))
 544                        ""
 545                      (substring nodename (match-beginning 2) (match-end 2)))
 546           nodename (substring nodename (match-beginning 3) (match-end 3)))
 547     (let ((trim (string-match "\\s *\\'" filename)))
 548       (if trim (setq filename (substring filename 0 trim))))
 549     (let ((trim (string-match "\\s *\\'" nodename)))
 550       (if trim (setq nodename (substring nodename 0 trim))))
 551     (Info-find-node (if (equal filename "") nil filename)
 552                     (if (equal nodename "") "Top" nodename))))
 553
 554 (defun Info-read-node-name (prompt &optional default)
 555   (let* ((completion-ignore-case t)
 556          (nodename (completing-read prompt (Info-build-node-completions))))
 557     (if (equal nodename "")
 558         (or default
 559             (Info-read-node-name prompt))
 560       nodename)))
 561
 562 (defun Info-build-node-completions ()
 563   (or Info-current-file-completions
 564       (let ((compl nil))
 565         (save-excursion
 566           (save-restriction
 567             (if (marker-buffer Info-tag-table-marker)
 568                 (progn
 569                   (set-buffer (marker-buffer Info-tag-table-marker))
 570                   (widen)
 571                   (goto-char Info-tag-table-marker)
 572                   (while (re-search-forward "\nNode: \\(.*\\)\177" nil t)
 573                     (setq compl
 574                           (cons (list (buffer-substring (match-beginning 1)
 575                                                         (match-end 1)))
 576                                 compl))))
 577               (widen)
 578               (goto-char (point-min))
 579               (while (search-forward "\n\^_" nil t)
 580                 (forward-line 1)
 581                 (let ((beg (point)))
 582                   (forward-line 1)
 583                   (if (re-search-backward "Node: *\\([^,\n]*\\) *[,\n\t]"
 584                                           beg t)
 585                       (setq compl
 586                             (cons (list (buffer-substring (match-beginning 1)
 587                                                           (match-end 1)))
 588                                   compl))))))))
 589         (setq Info-current-file-completions compl))))
 590 \f
 591 (defun Info-restore-point (hl)
 592   "If this node has been visited, restore the point value when we left."
 593   (while hl
 594     (if (and (equal (nth 0 (car hl)) Info-current-file)
 595              (equal (nth 1 (car hl)) Info-current-node))
 596         (progn
 597           (goto-char (nth 2 (car hl)))
 598           (setq hl nil))                ;terminate the while at next iter
 599       (setq hl (cdr hl)))))
 600 \f
 601 (defvar Info-last-search nil
 602   "Default regexp for \\<Info-mode-map>\\[Info-search] command to search for.")
 603
 604 (defun Info-search (regexp)
 605   "Search for REGEXP, starting from point, and select node it's found in."
 606   (interactive "sSearch (regexp): ")
 607   (if (equal regexp "")
 608       (setq regexp Info-last-search)
 609     (setq Info-last-search regexp))
 610   (let ((found ()) current
 611         (onode Info-current-node)
 612         (ofile Info-current-file)
 613         (opoint (point))
 614         (osubfile Info-current-subfile))
 615     (save-excursion
 616       (save-restriction
 617         (widen)
 618         (if (null Info-current-subfile)
 619             (progn (re-search-forward regexp) (setq found (point)))
 620           (condition-case err
 621               (progn (re-search-forward regexp) (setq found (point)))
 622             (search-failed nil)))))
 623     (if (not found) ;can only happen in subfile case -- else would have erred
 624         (unwind-protect
 625             (let ((list ()))
 626               (set-buffer (marker-buffer Info-tag-table-marker))
 627               (goto-char (point-min))
 628               (search-forward "\n\^_\nIndirect:")
 629               (save-restriction
 630                 (narrow-to-region (point)
 631                                   (progn (search-forward "\n\^_")
 632                                          (1- (point))))
 633                 (goto-char (point-min))
 634                 (search-forward (concat "\n" osubfile ": "))
 635                 (beginning-of-line)
 636                 (while (not (eobp))
 637                   (re-search-forward "\\(^.*\\): [0-9]+$")
 638                   (goto-char (+ (match-end 1) 2))
 639                   (setq list (cons (cons (read (current-buffer))
 640                                          (buffer-substring (match-beginning 1)
 641                                                            (match-end 1)))
 642                                    list))
 643                   (goto-char (1+ (match-end 0))))
 644                 (setq list (nreverse list)
 645                       current (car (car list))
 646                       list (cdr list)))
 647               (while list
 648                 (message "Searching subfile %s..." (cdr (car list)))
 649                 (Info-read-subfile (car (car list)))
 650                 (setq list (cdr list))
 651                 (goto-char (point-min))
 652                 (if (re-search-forward regexp nil t)
 653                     (setq found (point) list ())))
 654               (if found
 655                   (message "")
 656                 (signal 'search-failed (list regexp))))
 657           (if (not found)
 658               (progn (Info-read-subfile opoint)
 659                      (goto-char opoint)
 660                      (Info-select-node)))))
 661     (widen)
 662     (goto-char found)
 663     (Info-select-node)
 664     (or (and (equal onode Info-current-node)
 665              (equal ofile Info-current-file))
 666         (setq Info-history (cons (list ofile onode opoint)
 667                                  Info-history)))))
 668 \f
 669 ;; Extract the value of the node-pointer named NAME.
 670 ;; If there is none, use ERRORNAME in the error message;
 671 ;; if ERRORNAME is nil, just return nil.
 672 (defun Info-extract-pointer (name &optional errorname)
 673   (save-excursion
 674    (goto-char (point-min))
 675    (forward-line 1)
 676    (if (re-search-backward (concat name ":") nil t)
 677        (progn
 678          (goto-char (match-end 0))
 679          (Info-following-node-name))
 680      (if (eq errorname t)
 681          nil
 682        (error (concat "Node has no " (capitalize (or errorname name))))))))
 683
 684 ;; Return the node name in the buffer following point.
 685 ;; ALLOWEDCHARS, if non-nil, goes within [...] to make a regexp
 686 ;; saying which chas may appear in the node name.
 687 (defun Info-following-node-name (&optional allowedchars)
 688   (skip-chars-forward " \t")
 689   (buffer-substring
 690    (point)
 691    (progn
 692      (while (looking-at (concat "[" (or allowedchars "^,\t\n") "]"))
 693        (skip-chars-forward (concat (or allowedchars "^,\t\n") "("))
 694        (if (looking-at "(")
 695            (skip-chars-forward "^)")))
 696      (skip-chars-backward " ")
 697      (point))))
 698
 699 (defun Info-next ()
 700   "Go to the next node of this node."
 701   (interactive)
 702   (Info-goto-node (Info-extract-pointer "next")))
 703
 704 (defun Info-prev ()
 705   "Go to the previous node of this node."
 706   (interactive)
 707   (Info-goto-node (Info-extract-pointer "prev[ious]*" "previous")))
 708
 709 (defun Info-up ()
 710   "Go to the superior node of this node."
 711   (interactive)
 712   (Info-goto-node (Info-extract-pointer "up"))
 713   (Info-restore-point Info-history))
 714
 715 (defun Info-last ()
 716   "Go back to the last node visited."
 717   (interactive)
 718   (or Info-history
 719       (error "This is the first Info node you looked at"))
 720   (let (filename nodename opoint)
 721     (setq filename (car (car Info-history)))
 722     (setq nodename (car (cdr (car Info-history))))
 723     (setq opoint (car (cdr (cdr (car Info-history)))))
 724     (setq Info-history (cdr Info-history))
 725     (Info-find-node filename nodename)
 726     (setq Info-history (cdr Info-history))
 727     (goto-char opoint)))
 728
 729 (defun Info-directory ()
 730   "Go to the Info directory node."
 731   (interactive)
 732   (Info-find-node "dir" "top"))
 733 \f
 734 (defun Info-follow-reference (footnotename)
 735   "Follow cross reference named NAME to the node it refers to.
 736 NAME may be an abbreviation of the reference name."
 737   (interactive
 738    (let ((completion-ignore-case t)
 739          completions default alt-default (start-point (point)) str i bol eol)
 740      (save-excursion
 741        ;; Store end and beginning of line.
 742        (end-of-line)
 743        (setq eol (point))
 744        (beginning-of-line)
 745        (setq bol (point))
 746
 747        (goto-char (point-min))
 748        (while (re-search-forward "\\*note[ \n\t]*\\([^:]*\\):" nil t)
 749          (setq str (buffer-substring
 750                     (match-beginning 1)
 751                     (1- (point))))
 752          ;; See if this one should be the default.
 753          (and (null default)
 754               (<= (match-beginning 0) start-point)
 755               (<= start-point (point))
 756               (setq default t))
 757          ;; See if this one should be the alternate default.
 758          (and (null alt-default)
 759               (and (<= bol (match-beginning 0))
 760                    (<= (point) eol))
 761               (setq alt-default t))
 762          (setq i 0)
 763          (while (setq i (string-match "[ \n\t]+" str i))
 764            (setq str (concat (substring str 0 i) " "
 765                              (substring str (match-end 0))))
 766            (setq i (1+ i)))
 767          ;; Record as a completion and perhaps as default.
 768          (if (eq default t) (setq default str))
 769          (if (eq alt-default t) (setq alt-default str))
 770          (setq completions
 771                (cons (cons str nil)
 772                      completions))))
 773      ;; If no good default was found, try an alternate.
 774      (or default
 775          (setq default alt-default))
 776      ;; If only one cross-reference found, then make it default.
 777      (if (eq (length completions) 1)
 778          (setq default (car (car completions))))
 779      (if completions
 780          (let ((input (completing-read (if default
 781                                            (concat "Follow reference named: ("
 782                                                    default ") ")
 783                                          "Follow reference named: ")
 784                                        completions nil t)))
 785            (list (if (equal input "")
 786                      default input)))
 787        (error "No cross-references in this node"))))
 788   (let (target beg i (str (concat "\\*note " footnotename)))
 789     (while (setq i (string-match " " str i))
 790       (setq str (concat (substring str 0 i) "[ \t\n]+" (substring str (1+ i))))
 791       (setq i (+ i 6)))
 792     (save-excursion
 793       (goto-char (point-min))
 794       (or (re-search-forward str nil t)
 795           (error "No cross-reference named %s" footnotename))
 796       (goto-char (+ (match-beginning 0) 5))
 797       (setq target
 798             (Info-extract-menu-node-name "Bad format cross reference" t)))
 799     (while (setq i (string-match "[ \t\n]+" target i))
 800       (setq target (concat (substring target 0 i) " "
 801                            (substring target (match-end 0))))
 802       (setq i (+ i 1)))
 803     (Info-goto-node target)))
 804
 805 (defun Info-extract-menu-node-name (&optional errmessage multi-line)
 806   (skip-chars-forward " \t\n")
 807   (let ((beg (point))
 808         str i)
 809     (skip-chars-forward "^:")
 810     (forward-char 1)
 811     (setq str
 812           (if (looking-at ":")
 813               (buffer-substring beg (1- (point)))
 814             (skip-chars-forward " \t\n")
 815             (Info-following-node-name (if multi-line "^.,\t" "^.,\t\n"))))
 816     (while (setq i (string-match "\n" str i))
 817       (aset str i ?\ ))
 818     str))
 819
 820 ;; No one calls this and Info-menu-item doesn't exist.
 821 ;;(defun Info-menu-item-sequence (list)
 822 ;;  (while list
 823 ;;    (Info-menu-item (car list))
 824 ;;    (setq list (cdr list))))
 825
 826 (defun Info-menu (menu-item)
 827   "Go to node for menu item named (or abbreviated) NAME.
 828 Completion is allowed, and the menu item point is on is the default."
 829   (interactive
 830    (let ((completions '())
 831          ;; If point is within a menu item, use that item as the default
 832          (default nil)
 833          (p (point))
 834          (last nil))
 835      (save-excursion
 836        (goto-char (point-min))
 837        (if (not (search-forward "\n* menu:" nil t))
 838            (error "No menu in this node"))
 839        (while (re-search-forward
 840                 "\n\\* \\([^:\t\n]*\\):" nil t)
 841          (if (and (null default)
 842                   (prog1 (if last (< last p) nil)
 843                     (setq last (match-beginning 0)))
 844                   (<= p last))
 845              (setq default (car (car completions))))
 846          (setq completions (cons (cons (buffer-substring
 847                                          (match-beginning 1)
 848                                          (match-end 1))
 849                                        (match-beginning 1))
 850                                  completions)))
 851        (if (and (null default) last
 852                 (< last p)
 853                 (<= p (progn (end-of-line) (point))))
 854            (setq default (car (car completions)))))
 855      (let ((item nil))
 856        (while (null item)
 857          (setq item (let ((completion-ignore-case t))
 858                       (completing-read (if default
 859                                            (format "Menu item (default %s): "
 860                                                    default)
 861                                            "Menu item: ")
 862                                        completions nil t)))
 863          ;; we rely on the fact that completing-read accepts an input
 864          ;; of "" even when the require-match argument is true and ""
 865          ;; is not a valid possibility
 866          (if (string= item "")
 867              (if default
 868                  (setq item default)
 869                  ;; ask again
 870                  (setq item nil))))
 871        (list item))))
 872   ;; there is a problem here in that if several menu items have the same
 873   ;; name you can only go to the node of the first with this command.
 874   (Info-goto-node (Info-extract-menu-item menu-item)))
 875
 876 (defun Info-extract-menu-item (menu-item)
 877   (setq menu-item (regexp-quote menu-item))
 878   (save-excursion
 879     (goto-char (point-min))
 880     (or (search-forward "\n* menu:" nil t)
 881         (error "No menu in this node"))
 882     (or (re-search-forward (concat "\n\\* " menu-item ":") nil t)
 883         (re-search-forward (concat "\n\\* " menu-item) nil t)
 884         (error "No such item in menu"))
 885     (beginning-of-line)
 886     (forward-char 2)
 887     (Info-extract-menu-node-name)))
 888
 889 ;; If COUNT is nil, use the last item in the menu.
 890 (defun Info-extract-menu-counting (count)
 891   (save-excursion
 892     (goto-char (point-min))
 893     (or (search-forward "\n* menu:" nil t)
 894         (error "No menu in this node"))
 895     (if count
 896         (or (search-forward "\n* " nil t count)
 897             (error "Too few items in menu"))
 898       (while (search-forward "\n* " nil t)
 899         nil))
 900     (Info-extract-menu-node-name)))
 901
 902 (defun Info-nth-menu-item ()
 903   "Go to the node of the Nth menu item.
 904 N is the digit argument used to invoke this command."
 905   (interactive)
 906   (Info-goto-node
 907    (Info-extract-menu-counting
 908     (- (aref (this-command-keys) (1- (length (this-command-keys)))) ?0))))
 909
 910 (defun Info-top-node ()
 911   "Go to the Top node of this file."
 912   (interactive)
 913   (Info-goto-node "Top"))
 914
 915 (defun Info-final-node ()
 916   "Go to the final node in this file."
 917   (interactive)
 918   (Info-goto-node "Top")
 919   (let (Info-history)
 920     ;; Go to the last node in the menu of Top.
 921     (Info-goto-node (Info-extract-menu-counting nil))
 922     ;; If the last node in the menu is not last in pointer structure,
 923     ;; move forward until we can't go any farther.
 924     (while (Info-forward-node t t) nil)
 925     ;; Then keep moving down to last subnode, unless we reach an index.
 926     (while (and (not (string-match "\\<index\\>" Info-current-node))
 927                 (save-excursion (search-forward "\n* Menu:" nil t)))
 928       (Info-goto-node (Info-extract-menu-counting nil)))))
 929
 930 (defun Info-forward-node (&optional not-down no-error)
 931   "Go forward one node, considering all nodes as forming one sequence."
 932   (interactive)
 933   (goto-char (point-min))
 934   (forward-line 1)
 935   ;; three possibilities, in order of priority:
 936   ;;     1. next node is in a menu in this node (but not in an index)
 937   ;;     2. next node is next at same level
 938   ;;     3. next node is up and next
 939   (cond ((and (not not-down)
 940               (save-excursion (search-forward "\n* menu:" nil t))
 941               (not (string-match "\\<index\\>" Info-current-node)))
 942          (Info-goto-node (Info-extract-menu-counting 1))
 943          t)
 944         ((save-excursion (search-backward "next:" nil t))
 945          (Info-next)
 946          t)
 947         ((and (save-excursion (search-backward "up:" nil t))
 948               (not (equal (downcase (Info-extract-pointer "up")) "top")))
 949          (let ((old-node Info-current-node))
 950            (Info-up)
 951            (let (Info-history success)
 952              (unwind-protect
 953                  (setq success (Info-forward-node t no-error))
 954                (or success (Info-goto-node old-node))))))
 955         (no-error nil)
 956         (t (error "No pointer forward from this node"))))
 957
 958 (defun Info-backward-node ()
 959   "Go backward one node, considering all nodes as forming one sequence."
 960   (interactive)
 961   (let ((prevnode (Info-extract-pointer "prev[ious]*" t))
 962         (upnode (Info-extract-pointer "up" t)))
 963     (cond ((and upnode (string-match "(" upnode))
 964            (error "First node in file"))
 965           ((and upnode (or (null prevnode)
 966                            (equal (downcase prevnode) (downcase upnode))))
 967            (Info-up))
 968           (prevnode
 969            ;; If we move back at the same level,
 970            ;; go down to find the last subnode*.
 971            (Info-prev)
 972            (let (Info-history)
 973              (while (and (not (string-match "\\<index\\>" Info-current-node))
 974                          (save-excursion (search-forward "\n* Menu:" nil t)))
 975                (Info-goto-node (Info-extract-menu-counting nil)))))
 976           (t
 977            (error "No pointer backward from this node")))))
 978
 979 (defun Info-exit ()
 980   "Exit Info by selecting some other buffer."
 981   (interactive)
 982   (if Info-standalone
 983       (save-buffers-kill-emacs)
 984     (switch-to-buffer (prog1 (other-buffer (current-buffer))
 985                         (bury-buffer (current-buffer))))))
 986
 987 (defun Info-next-menu-item ()
 988   (interactive)
 989   (save-excursion
 990     (forward-line -1)
 991     (search-forward "\n* menu:" nil t)
 992     (or (search-forward "\n* " nil t)
 993         (error "No more items in menu"))
 994     (Info-goto-node (Info-extract-menu-node-name))))
 995
 996 (defun Info-last-menu-item ()
 997   (interactive)
 998   (save-excursion
 999     (forward-line 1)
1000     (search-backward "\n* menu:" nil t)
1001     (or (search-backward "\n* " nil t)
1002         (error "No previous items in menu"))
1003     (Info-goto-node (Info-extract-menu-node-name))))
1004
1005 (defmacro Info-no-error (&rest body)
1006   (list 'condition-case nil (cons 'progn (append body '(t))) '(error nil)))
1007
1008 (defun Info-next-preorder ()
1009   "Go to the next node, popping up a level if there is none."
1010   (interactive)
1011   (cond ((looking-at "\\*note[ \n]*\\([^:]*\\):")
1012          (Info-follow-reference
1013           (buffer-substring (match-beginning 1) (match-end 1))))
1014         ((Info-no-error (Info-next-menu-item))  )
1015         ((Info-no-error (Info-up))              (forward-line 1))
1016         (t                                      (error "No more nodes"))))
1017
1018 (defun Info-last-preorder ()
1019   "Go to the last node, popping up a level if there is none."
1020   (interactive)
1021   (cond ((Info-no-error (Info-last-menu-item))  )
1022         ((Info-no-error (Info-up))              (forward-line -1))
1023         (t                                      (error "No previous nodes"))))
1024
1025 (defun Info-scroll-up ()
1026   "Read the next screen.  If end of buffer is visible, go to next entry."
1027   (interactive)
1028   (if (pos-visible-in-window-p (point-max))
1029       (Info-next-preorder)
1030       (scroll-up))
1031   )
1032
1033 (defun Info-scroll-down ()
1034   "Read the previous screen.  If start of buffer is visible, go to last entry."
1035   (interactive)
1036   (if (pos-visible-in-window-p (point-min))
1037       (Info-last-preorder)
1038       (scroll-down))
1039   )
1040
1041 (defun Info-next-reference ()
1042   "Move cursor to the next cross-reference or menu item in the node."
1043   (interactive)
1044   (let ((pat "\\*note[ \n\t]*\\([^:]*\\):\\|^\\* .*:")
1045         (old-pt (point)))
1046     (or (eobp) (forward-char 1))
1047     (or (re-search-forward pat nil t)
1048         (progn
1049           (goto-char (point-min))
1050           (or (re-search-forward pat nil t)
1051               (progn
1052                 (goto-char old-pt)
1053                 (error "No cross references in this node")))))
1054     (goto-char (match-beginning 0))
1055     (if (looking-at "\\* Menu:")
1056         (Info-next-reference))))
1057
1058 (defun Info-prev-reference ()
1059   "Move cursor to the previous cross-reference or menu item in the node."
1060   (interactive)
1061   (let ((pat "\\*note[ \n\t]*\\([^:]*\\):\\|^\\* .*:")
1062         (old-pt (point)))
1063     (or (re-search-backward pat nil t)
1064         (progn
1065           (goto-char (point-max))
1066           (or (re-search-backward pat nil t)
1067               (progn
1068                 (goto-char old-pt)
1069                 (error "No cross references in this node")))))
1070     (goto-char (match-beginning 0))
1071     (if (looking-at "\\* Menu:")
1072         (Info-prev-reference))))
1073
1074 (defun Info-index (topic)
1075   "Look up a string in the index for this file.
1076 The index is defined as the first node in the top-level menu whose
1077 name contains the word \"Index\", plus any immediately following
1078 nodes whose names also contain the word \"Index\".
1079 If there are no exact matches to the specified topic, this chooses
1080 the first match which is a case-insensitive substring of a topic.
1081 Use the `,' command to see the other matches.
1082 Give a blank topic name to go to the Index node itself."
1083   (interactive "sIndex topic: ")
1084   (let ((orignode Info-current-node)
1085         (rnode nil)
1086         (pattern (format "\n\\* \\([^\n:]*%s[^\n:]*\\):[ \t]*\\([^.\n]*\\)\\.[ t]*\\([0-9]*\\)"
1087                          (regexp-quote topic)))
1088         node)
1089     (Info-goto-node "Top")
1090     (or (search-forward "\n* menu:" nil t)
1091         (error "No index"))
1092     (or (re-search-forward "\n\\* \\(.*\\<Index\\>\\)" nil t)
1093         (error "No index"))
1094     (goto-char (match-beginning 1))
1095     (let ((Info-keeping-history nil))
1096       (Info-goto-node (Info-extract-menu-node-name)))
1097     (or (equal topic "")
1098         (let ((matches nil)
1099               (exact nil)
1100               (Info-keeping-history nil)
1101               found)
1102           (while
1103               (progn
1104                 (goto-char (point-min))
1105                 (while (re-search-forward pattern nil t)
1106                   (setq matches
1107                         (cons (list (buffer-substring (match-beginning 1)
1108                                                       (match-end 1))
1109                                     (buffer-substring (match-beginning 2)
1110                                                       (match-end 2))
1111                                     Info-current-node
1112                                     (string-to-int (concat "0"
1113                                                            (buffer-substring
1114                                                             (match-beginning 3)
1115                                                             (match-end 3)))))
1116                               matches)))
1117                 (and (setq node (Info-extract-pointer "next" t))
1118                      (string-match "\\<Index\\>" node)))
1119             (Info-goto-node node))
1120           (or matches
1121               (progn
1122                 (Info-last)
1123                 (error "No \"%s\" in index" topic)))
1124           ;; Here it is a feature that assoc is case-sensitive.
1125           (while (setq found (assoc topic matches))
1126             (setq exact (cons found exact)
1127                   matches (delq found matches)))
1128           (setq Info-index-alternatives (nconc exact (nreverse matches)))
1129           (Info-index-next 0)))))
1130
1131 (defun Info-index-next (num)
1132   "Go to the next matching index item from the last `i' command."
1133   (interactive "p")
1134   (or Info-index-alternatives
1135       (error "No previous `i' command in this file"))
1136   (while (< num 0)
1137     (setq num (+ num (length Info-index-alternatives))))
1138   (while (> num 0)
1139     (setq Info-index-alternatives
1140           (nconc (cdr Info-index-alternatives)
1141                  (list (car Info-index-alternatives)))
1142           num (1- num)))
1143   (Info-goto-node (nth 1 (car Info-index-alternatives)))
1144   (if (> (nth 3 (car Info-index-alternatives)) 0)
1145       (forward-line (nth 3 (car Info-index-alternatives)))
1146     (forward-line 3)  ; don't search in headers
1147     (let ((name (car (car Info-index-alternatives))))
1148       (if (or (re-search-forward (format
1149                                   "\\(Function\\|Command\\): %s\\( \\|$\\)"
1150                                   (regexp-quote name)) nil t)
1151               (search-forward (format "`%s'" name) nil t)
1152               (and (string-match "\\`.*\\( (.*)\\)\\'" name)
1153                    (search-forward
1154                     (format "`%s'" (substring name 0 (match-beginning 1)))
1155                     nil t))
1156               (search-forward name nil t))
1157           (beginning-of-line)
1158         (goto-char (point-min)))))
1159   (message "Found \"%s\" in %s.  %s"
1160            (car (car Info-index-alternatives))
1161            (nth 2 (car Info-index-alternatives))
1162            (if (cdr Info-index-alternatives)
1163                "(Press `,' for more)"
1164              "(Only match)")))
1165
1166 (defun Info-undefined ()
1167   "Make command be undefined in Info."
1168   (interactive)
1169   (ding))
1170
1171 (defun Info-help ()
1172   "Enter the Info tutorial."
1173   (interactive)
1174   (delete-other-windows)
1175   (Info-find-node "info"
1176                   (if (< (window-height) 23)
1177                       "Help-Small-Screen"
1178                     "Help")))
1179
1180 (defun Info-summary ()
1181   "Display a brief summary of all Info commands."
1182   (interactive)
1183   (save-window-excursion
1184     (switch-to-buffer "*Help*")
1185     (erase-buffer)
1186     (insert (documentation 'Info-mode))
1187     (goto-char (point-min))
1188     (let (ch flag)
1189       (while (progn (setq flag (not (pos-visible-in-window-p (point-max))))
1190                     (message (if flag "Type Space to see more"
1191                                "Type Space to return to Info"))
1192                     (if (not (eq ?\  (setq ch (read-event))))
1193                         (progn (setq unread-command-events (list ch)) nil)
1194                       flag))
1195         (scroll-up)))
1196     (bury-buffer "*Help*")))
1197 \f
1198 (defun Info-get-token (pos start all &optional errorstring)
1199   "Return the token around POS,
1200 POS must be somewhere inside the token
1201 START is a regular expression which will match the
1202     beginning of the tokens delimited string
1203 ALL is a regular expression with a single
1204     parenthized subpattern which is the token to be
1205     returned. E.g. '{\(.*\)}' would return any string
1206     enclosed in braces around POS.
1207 SIG optional fourth argument, controls action on no match
1208     nil: return nil
1209     t: beep
1210     a string: signal an error, using that string."
1211   (save-excursion
1212     (goto-char pos)
1213     (re-search-backward start (max (point-min) (- pos 200)) 'yes)
1214     (let (found)
1215       (while (and (re-search-forward all (min (point-max) (+ pos 200)) 'yes)
1216                   (not (setq found (and (<= (match-beginning 0) pos)
1217                                         (> (match-end 0) pos))))))
1218       (if (and found (<= (match-beginning 0) pos)
1219                (> (match-end 0) pos))
1220           (buffer-substring (match-beginning 1) (match-end 1))
1221         (cond ((null errorstring)
1222                nil)
1223               ((eq errorstring t)
1224                (beep)
1225                nil)
1226               (t
1227                (error "No %s around position %d" errorstring pos)))))))
1228
1229 (defun Info-follow-nearest-node (click)
1230   "\\<Info-mode-map>Follow a node reference near point.
1231 Like \\[Info-menu], \\[Info-follow-reference], \\[Info-next], \\[Info-prev] or \\[Info-up] command, depending on where you click.
1232 At end of the node's text, moves to the next node."
1233   (interactive "e")
1234   (let* ((start (event-start click))
1235          (window (car start))
1236          (pos (car (cdr start))))
1237     (select-window window)
1238     (goto-char pos))
1239   (let (node)
1240     (cond
1241      ((setq node (Info-get-token (point) "\\*note[ \n]" "\\*note[ \n]\\([^:]*\\):"))
1242       (Info-follow-reference node))
1243      ((setq node (Info-get-token (point) "\\* " "\\* \\([^:]*\\)::"))
1244       (Info-goto-node node))
1245      ((setq node (Info-get-token (point) "\\* " "\\* \\([^:]*\\):"))
1246       (Info-menu node))
1247      ((setq node (Info-get-token (point) "Up: " "Up: \\([^,\n\t]*\\)"))
1248       (Info-goto-node node))
1249      ((setq node (Info-get-token (point) "Next: " "Next: \\([^,\n\t]*\\)"))
1250       (Info-goto-node node))
1251      ((setq node (Info-get-token (point) "File: " "File: \\([^,\n\t]*\\)"))
1252       (Info-goto-node "Top"))
1253      ((setq node (Info-get-token (point) "Prev: " "Prev: \\([^,\n\t]*\\)"))
1254       (Info-goto-node node))
1255      ((save-excursion (forward-line 1) (eobp))
1256       (Info-next)))
1257     ))
1258 \f
1259 (defvar Info-mode-map nil
1260   "Keymap containing Info commands.")
1261 (if Info-mode-map
1262     nil
1263   (setq Info-mode-map (make-keymap))
1264   (suppress-keymap Info-mode-map)
1265   (define-key Info-mode-map "." 'beginning-of-buffer)
1266   (define-key Info-mode-map " " 'Info-scroll-up)
1267   (define-key Info-mode-map "\C-m" 'Info-next-preorder)
1268   (define-key Info-mode-map "\t" 'Info-next-reference)
1269   (define-key Info-mode-map "\e\t" 'Info-prev-reference)
1270   (define-key Info-mode-map "1" 'Info-nth-menu-item)
1271   (define-key Info-mode-map "2" 'Info-nth-menu-item)
1272   (define-key Info-mode-map "3" 'Info-nth-menu-item)
1273   (define-key Info-mode-map "4" 'Info-nth-menu-item)
1274   (define-key Info-mode-map "5" 'Info-nth-menu-item)
1275   (define-key Info-mode-map "6" 'Info-nth-menu-item)
1276   (define-key Info-mode-map "7" 'Info-nth-menu-item)
1277   (define-key Info-mode-map "8" 'Info-nth-menu-item)
1278   (define-key Info-mode-map "9" 'Info-nth-menu-item)
1279   (define-key Info-mode-map "0" 'undefined)
1280   (define-key Info-mode-map "?" 'Info-summary)
1281   (define-key Info-mode-map "]" 'Info-forward-node)
1282   (define-key Info-mode-map "[" 'Info-backward-node)
1283   (define-key Info-mode-map "<" 'Info-top-node)
1284   (define-key Info-mode-map ">" 'Info-final-node)
1285   (define-key Info-mode-map "b" 'beginning-of-buffer)
1286   (define-key Info-mode-map "d" 'Info-directory)
1287   (define-key Info-mode-map "e" 'Info-edit)
1288   (define-key Info-mode-map "f" 'Info-follow-reference)
1289   (define-key Info-mode-map "g" 'Info-goto-node)
1290   (define-key Info-mode-map "h" 'Info-help)
1291   (define-key Info-mode-map "i" 'Info-index)
1292   (define-key Info-mode-map "l" 'Info-last)
1293   (define-key Info-mode-map "m" 'Info-menu)
1294   (define-key Info-mode-map "n" 'Info-next)
1295   (define-key Info-mode-map "p" 'Info-prev)
1296   (define-key Info-mode-map "q" 'Info-exit)
1297   (define-key Info-mode-map "s" 'Info-search)
1298   (define-key Info-mode-map "t" 'Info-top-node)
1299   (define-key Info-mode-map "u" 'Info-up)
1300   (define-key Info-mode-map "," 'Info-index-next)
1301   (define-key Info-mode-map "\177" 'Info-scroll-down)
1302   (define-key Info-mode-map [mouse-2] 'Info-follow-nearest-node)
1303   )
1304 \f
1305 ;; Info mode is suitable only for specially formatted data.
1306 (put 'info-mode 'mode-class 'special)
1307
1308 (defun Info-mode ()
1309   "\\<Info-mode-map>
1310 Info mode provides commands for browsing through the Info documentation tree.
1311 Documentation in Info is divided into \"nodes\", each of which discusses
1312 one topic and contains references to other nodes which discuss related
1313 topics.  Info has commands to follow the references and show you other nodes.
1314
1315 \\[Info-help]   Invoke the Info tutorial.
1316
1317 Selecting other nodes:
1318 \\[Info-next]   Move to the \"next\" node of this node.
1319 \\[Info-prev]   Move to the \"previous\" node of this node.
1320 \\[Info-up]     Move \"up\" from this node.
1321 \\[Info-menu]   Pick menu item specified by name (or abbreviation).
1322         Picking a menu item causes another node to be selected.
1323 \\[Info-directory]      Go to the Info directory node.
1324 \\[Info-follow-reference]       Follow a cross reference.  Reads name of reference.
1325 \\[Info-last]   Move to the last node you were at.
1326 \\[Info-index]  Look up a topic in this file's Index and move to that node.
1327 \\[Info-index-next]     (comma) Move to the next match from a previous `i' command.
1328
1329 Moving within a node:
1330 \\[Info-scroll-up]      Normally, scroll forward a full screen.  If the end of the buffer is
1331 already visible, try to go to the next menu entry, or up if there is none.
1332 \\[Info-scroll-down]  Normally, scroll backward.  If the beginning of the buffer is
1333 already visible, try to go to the previous menu entry, or up if there is none.
1334 \\[beginning-of-buffer] Go to beginning of node.
1335
1336 Advanced commands:
1337 \\[Info-exit]   Quit Info: reselect previously selected buffer.
1338 \\[Info-edit]   Edit contents of selected node.
1339 1       Pick first item in node's menu.
1340 2, 3, 4, 5   Pick second ... fifth item in node's menu.
1341 \\[Info-goto-node]      Move to node specified by name.
1342         You may include a filename as well, as (FILENAME)NODENAME.
1343 \\[universal-argument] \\[info] Move to new Info file with completion.
1344 \\[Info-search] Search through this Info file for specified regexp,
1345         and select the node in which the next occurrence is found.
1346 \\[Info-next-preorder]  Next-preorder; that is, try to go to the next menu item,
1347         and if that fails try to move up, and if that fails, tell user
1348         he/she is done reading.
1349 \\[Info-next-reference] Move cursor to next cross-reference or menu item.
1350 \\[Info-prev-reference] Move cursor to previous cross-reference or menu item."
1351   (kill-all-local-variables)
1352   (setq major-mode 'Info-mode)
1353   (setq mode-name "Info")
1354   (use-local-map Info-mode-map)
1355   (set-syntax-table text-mode-syntax-table)
1356   (setq local-abbrev-table text-mode-abbrev-table)
1357   (setq case-fold-search t)
1358   (setq buffer-read-only t)
1359   (make-local-variable 'Info-current-file)
1360   (make-local-variable 'Info-current-subfile)
1361   (make-local-variable 'Info-current-node)
1362   (make-local-variable 'Info-tag-table-marker)
1363   (make-local-variable 'Info-history)
1364   (make-local-variable 'Info-index-alternatives)
1365   (if (fboundp 'make-face)
1366       (progn
1367         (make-face 'info-node)
1368         (make-face 'info-menu-5)
1369         (make-face 'info-xref)
1370         (or (face-differs-from-default-p 'info-node)
1371             (if (face-differs-from-default-p 'bold-italic)
1372                 (copy-face 'bold-italic 'info-node)
1373               (copy-face 'bold 'info-node)))
1374         (or (face-differs-from-default-p 'info-menu-5)
1375             (set-face-underline-p 'info-menu-5 t))
1376         (or (face-differs-from-default-p 'info-xref)
1377             (copy-face 'bold 'info-xref)))
1378     (setq Info-fontify nil))
1379   (Info-set-mode-line)
1380   (run-hooks 'Info-mode-hook))
1381
1382 (defvar Info-edit-map nil
1383   "Local keymap used within `e' command of Info.")
1384 (if Info-edit-map
1385     nil
1386   (setq Info-edit-map (nconc (make-sparse-keymap) text-mode-map))
1387   (define-key Info-edit-map "\C-c\C-c" 'Info-cease-edit))
1388
1389 ;; Info-edit mode is suitable only for specially formatted data.
1390 (put 'info-edit-mode 'mode-class 'special)
1391
1392 (defun Info-edit-mode ()
1393   "Major mode for editing the contents of an Info node.
1394 Like text mode with the addition of `Info-cease-edit'
1395 which returns to Info mode for browsing.
1396 \\{Info-edit-map}"
1397   )
1398
1399 (defun Info-edit ()
1400   "Edit the contents of this Info node.
1401 Allowed only if variable `Info-enable-edit' is non-nil."
1402   (interactive)
1403   (or Info-enable-edit
1404       (error "Editing info nodes is not enabled"))
1405   (use-local-map Info-edit-map)
1406   (setq major-mode 'Info-edit-mode)
1407   (setq mode-name "Info Edit")
1408   (kill-local-variable 'mode-line-buffer-identification)
1409   (setq buffer-read-only nil)
1410   ;; Make mode line update.
1411   (set-buffer-modified-p (buffer-modified-p))
1412   (message (substitute-command-keys
1413              "Editing: Type \\<Info-edit-map>\\[Info-cease-edit] to return to info")))
1414
1415 (defun Info-cease-edit ()
1416   "Finish editing Info node; switch back to Info proper."
1417   (interactive)
1418   ;; Do this first, so nothing has changed if user C-g's at query.
1419   (and (buffer-modified-p)
1420        (y-or-n-p "Save the file? ")
1421        (save-buffer))
1422   (use-local-map Info-mode-map)
1423   (setq major-mode 'Info-mode)
1424   (setq mode-name "Info")
1425   (Info-set-mode-line)
1426   (setq buffer-read-only t)
1427   ;; Make mode line update.
1428   (set-buffer-modified-p (buffer-modified-p))
1429   (and (marker-position Info-tag-table-marker)
1430        (buffer-modified-p)
1431        (message "Tags may have changed.  Use Info-tagify if necessary")))
1432 \f
1433 (defun Info-find-emacs-command-nodes (command)
1434   "Return a list of locations documenting COMMAND in the Emacs Info manual.
1435 The locations are of the format used in Info-history, i.e.
1436 \(FILENAME NODENAME BUFFERPOS\)."
1437   (require 'info)
1438   (let ((where '())
1439         (cmd-desc (concat "^\\* " (regexp-quote (symbol-name command))
1440                           ":\\s *\\(.*\\)\\.$")))
1441     (save-excursion
1442       (Info-find-node "emacs" "Command Index")
1443       ;; Take the index node off the Info history.
1444       (setq Info-history (cdr Info-history))
1445       (goto-char (point-max))
1446       (while (re-search-backward cmd-desc nil t)
1447           (setq where (cons (list Info-current-file
1448                                   (buffer-substring
1449                                    (match-beginning 1)
1450                                    (match-end 1))
1451                                   0)
1452                             where)))
1453       where)))
1454
1455 ;;;###autoload
1456 (defun Info-goto-emacs-command-node (command)
1457   "Go to the Info node in the Emacs manual for command COMMAND.
1458 The command is found by looking up in Emacs manual's Command Index."
1459   (interactive "CFind documentation for command: ")
1460   (or (commandp command)
1461       (signal 'wrong-type-argument (list 'commandp command)))
1462   (let ((where (Info-find-emacs-command-nodes command)))
1463     (if where
1464         (let ((num-matches (length where)))
1465           ;; Get Info running, and pop to it in another window.
1466           (save-window-excursion
1467             (info))
1468           (pop-to-buffer "*info*")
1469           (Info-find-node (car (car where))
1470                           (car (cdr (car where))))
1471           (if (> num-matches 1)
1472               (progn
1473                 ;; Info-find-node already pushed (car where) onto
1474                 ;; Info-history.  Put the other nodes that were found on
1475                 ;; the history.
1476                 (setq Info-history (nconc (cdr where) Info-history))
1477                 (message (substitute-command-keys
1478                           "Found %d other entr%s.  Use \\[Info-last] to see %s.")
1479                          (1- num-matches)
1480                          (if (> num-matches 2) "ies" "y")
1481                          (if (> num-matches 2) "them" "it")))))
1482       (error "Couldn't find documentation for %s." command))))
1483
1484 ;;;###autoload
1485 (defun Info-goto-emacs-key-command-node (key)
1486   "Go to the Info node in the Emacs manual the command bound to KEY, a string.
1487 Interactively, if the binding is execute-extended-command, a command is read.
1488 The command is found by looking up in Emacs manual's Command Index."
1489   (interactive "kFind documentation for key:")
1490   (let ((command (key-binding key)))
1491     (cond ((null command)
1492            (message "%s is undefined" (key-description key)))
1493           ((and (interactive-p)
1494                 (eq command 'execute-extended-command))
1495            (Info-goto-emacs-command-node
1496             (read-command "Find documentation for command: ")))
1497           (t
1498            (Info-goto-emacs-command-node command)))))
1499 \f
1500 (defun Info-fontify-node ()
1501   (save-excursion
1502     (let ((buffer-read-only nil))
1503       (goto-char (point-min))
1504       (if (looking-at "^File: [^,: \t]+,?[ \t]+")
1505           (progn
1506             (goto-char (match-end 0))
1507             (while
1508                 (looking-at "[ \t]*[^:, \t\n]+:[ \t]+\\([^:,\t\n]+\\),?")
1509               (goto-char (match-end 0))
1510               (put-text-property (match-beginning 1) (match-end 1)
1511                                  'face 'info-xref)
1512               (put-text-property (match-beginning 1) (match-end 1)
1513                                  'mouse-face 'highlight))))
1514       (goto-char (point-min))
1515       (while (re-search-forward "\\*Note[ \n\t]*\\([^:]*\\):" nil t)
1516         (if (= (char-after (1- (match-beginning 0))) ?\") ; hack
1517             nil
1518           (put-text-property (match-beginning 1) (match-end 1)
1519                              'face 'info-xref)
1520           (put-text-property (match-beginning 1) (match-end 1)
1521                              'mouse-face 'highlight)))
1522       (goto-char (point-min))
1523       (if (and (search-forward "\n* Menu:" nil t)
1524                (not (string-match "\\<Index\\>" Info-current-node))
1525                ;; Don't take time to annotate huge menus
1526                (< (- (point-max) (point)) 30000))
1527           (let ((n 0))
1528             (while (re-search-forward "^\\* \\([^:\t\n]*\\):" nil t)
1529               (setq n (1+ n))
1530               (if (memq n '(5 9))   ; visual aids to help with 1-9 keys
1531                   (put-text-property (match-beginning 0)
1532                                      (1+ (match-beginning 0))
1533                                      'face 'info-menu-5))
1534               (put-text-property (match-beginning 1) (match-end 1)
1535                                  'face 'info-node)
1536               (put-text-property (match-beginning 1) (match-end 1)
1537                                  'mouse-face 'highlight))))
1538       (set-buffer-modified-p nil))))
1539
1540 (provide 'info)
1541
1542 ;;; info.el ends here