1 ;;; help.el --- help commands for Emacs
3 ;; Copyright (C) 1985, 1986, 1993, 1994, 1998, 1999, 2000, 2001
4 ;; Free Software Foundation, Inc.
7 ;; Keywords: help, internal
9 ;; This file is part of GNU Emacs.
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)
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.
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 the
23 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
24 ;; Boston, MA 02111-1307, USA.
28 ;; This code implements GNU Emacs' on-line help system, the one invoked by
29 ;; `M-x help-for-help'.
33 ;; Get the macro make-help-screen when this is compiled,
34 ;; or run interpreted, but not when the compiled code is loaded.
35 (eval-when-compile (require 'help-macro
))
36 (eval-when-compile (require 'view
))
38 (defvar help-map
(make-sparse-keymap)
39 "Keymap for characters following the Help key.")
41 (defvar help-mode-map
(make-sparse-keymap)
42 "Keymap for help mode.")
44 (define-key global-map
(char-to-string help-char
) 'help-command
)
45 (define-key global-map
[help] 'help-command)
46 (define-key global-map [f1] 'help-command)
47 (fset 'help-command help-map)
49 (define-key help-map (char-to-string help-char) 'help-for-help)
50 (define-key help-map [help] 'help-for-help
)
51 (define-key help-map
[f1] 'help-for-help)
52 (define-key help-map "?" 'help-for-help)
54 (define-key help-map "\C-c" 'describe-copying)
55 (define-key help-map "\C-d" 'describe-distribution)
56 (define-key help-map "\C-w" 'describe-no-warranty)
57 (define-key help-map "\C-p" 'describe-project)
58 (define-key help-map "a" 'apropos-command)
60 (define-key help-map "b" 'describe-bindings)
62 (define-key help-map "c" 'describe-key-briefly)
63 (define-key help-map "k" 'describe-key)
65 (define-key help-map "d" 'describe-function)
66 (define-key help-map "f" 'describe-function)
68 (define-key help-map "F" 'view-emacs-FAQ)
70 (define-key help-map "i" 'info)
71 (define-key help-map "4i" 'info-other-window)
72 (define-key help-map "\C-f" 'Info-goto-emacs-command-node)
73 (define-key help-map "\C-k" 'Info-goto-emacs-key-command-node)
74 (define-key help-map "\C-i" 'info-lookup-symbol)
76 (define-key help-map "l" 'view-lossage)
78 (define-key help-map "m" 'describe-mode)
79 (define-key help-map "\C-m" 'view-order-manuals)
81 (define-key help-map "\C-n" 'view-emacs-news)
82 (define-key help-map "n" 'view-emacs-news)
84 (define-key help-map "p" 'finder-by-keyword)
85 (autoload 'finder-by-keyword "finder"
86 "Find packages matching a given keyword." t)
88 (define-key help-map "P" 'view-emacs-problems)
90 (define-key help-map "s" 'describe-syntax)
92 (define-key help-map "t" 'help-with-tutorial)
94 (define-key help-map "w" 'where-is)
96 (define-key help-map "v" 'describe-variable)
98 (define-key help-map "q" 'help-quit)
100 (define-key help-mode-map [mouse-2] 'help-follow-mouse)
101 (define-key help-mode-map "\C-c\C-b" 'help-go-back)
102 (define-key help-mode-map "\C-c\C-c" 'help-follow)
103 (define-key help-mode-map "\t" 'help-next-ref)
104 (define-key help-mode-map [backtab] 'help-previous-ref)
105 (define-key help-mode-map [(shift tab)] 'help-previous-ref)
106 ;; Documentation only, since we use minor-mode-overriding-map-alist.
107 (define-key help-mode-map "\r" 'help-follow)
109 (defvar help-xref-stack nil
110 "A stack of ways by which to return to help buffers after following xrefs.
111 Used by `help-follow' and `help-xref-go-back'.
112 An element looks like (POSITION FUNCTION ARGS...), where POSITION is
113 `(POINT . BUFFER-NAME)'.
114 To use the element, do (apply FUNCTION ARGS) then goto the point in
116 (put 'help-xref-stack 'permanent-local t)
118 (defvar help-xref-stack-item nil
119 "An item for `help-follow' in this buffer to push onto `help-xref-stack'.
120 The format is (FUNCTION ARGS...).")
121 (put 'help-xref-stack-item 'permanent-local t)
123 (setq-default help-xref-stack nil help-xref-stack-item nil)
125 (defcustom help-mode-hook nil
126 "Hook run by `help-mode'."
131 "Major mode for viewing help text and navigating references in it.
132 Entry to this mode runs the normal hook `help-mode-hook'.
136 (kill-all-local-variables)
137 (use-local-map help-mode-map)
138 (setq mode-name "Help")
139 (setq major-mode 'help-mode)
140 (make-local-variable 'font-lock-defaults)
141 (setq font-lock-defaults nil) ; font-lock would defeat xref
143 (make-local-variable 'view-no-disable-on-exit)
144 (setq view-no-disable-on-exit t)
145 (run-hooks 'help-mode-hook))
147 (defun help-mode-setup ()
149 (setq buffer-read-only nil))
151 (add-hook 'temp-buffer-setup-hook 'help-mode-setup)
153 (defun help-mode-finish ()
154 (when (eq major-mode 'help-mode)
155 ;; View mode's read-only status of existing *Help* buffer is lost
156 ;; by with-output-to-temp-buffer.
158 (help-make-xrefs (current-buffer)))
159 (setq view-return-to-alist
160 (list (cons (selected-window) help-return-method))))
162 (add-hook 'temp-buffer-show-hook 'help-mode-finish)
165 "Just exit from the Help command's command loop."
169 (defun help-with-tutorial (&optional arg)
170 "Select the Emacs learn-by-doing tutorial.
171 If there is a tutorial version written in the language
172 of the selected language environment, that version is used.
173 If there's no tutorial in that language, `TUTORIAL' is selected.
174 With arg, you are asked to choose which language."
177 (read-language-name 'tutorial "Language: " "English")
178 (if (get-language-info current-language-environment 'tutorial)
179 current-language-environment
182 (setq filename (get-language-info lang 'tutorial))
183 (setq file (expand-file-name (concat "~/" filename)))
184 (delete-other-windows)
185 (if (get-file-buffer file)
186 (switch-to-buffer (get-file-buffer file))
187 (switch-to-buffer (create-file-buffer file))
188 (setq buffer-file-name file)
189 (setq default-directory (expand-file-name "~/"))
190 (setq buffer-auto-save-file-name nil)
191 (insert-file-contents (expand-file-name filename data-directory))
192 (goto-char (point-min))
193 (search-forward "\n<<")
195 (delete-region (point) (progn (end-of-line) (point)))
196 (let ((n (- (window-height (selected-window))
197 (count-lines (point-min) (point))
201 ;; Some people get confused by the large gap.
203 (insert "[Middle of page left blank for didactic purposes. "
204 "Text continues below]")
205 (newline (- n (/ n 2)))))
206 (goto-char (point-min))
207 (set-buffer-modified-p nil))))
209 (defun mode-line-key-binding (key)
210 "Value is the binding of KEY in the mode line or nil if none."
211 (let (string-info defn)
212 (when (and (eq 'mode-line (aref key 0))
213 (consp (setq string-info (nth 4 (event-start (aref key 1))))))
214 (let* ((string (car string-info))
215 (pos (cdr string-info))
216 (local-map (and (> pos 0)
217 (< pos (length string))
218 (get-text-property pos 'local-map string))))
219 (setq defn (and local-map (lookup-key local-map key)))))
222 (defun describe-key-briefly (key &optional insert)
223 "Print the name of the function KEY invokes. KEY is a string.
224 If INSERT (the prefix arg) is non-nil, insert the message in the buffer."
225 (interactive "kDescribe key briefly: \nP")
227 (let ((modifiers (event-modifiers (aref key 0)))
228 (standard-output (if insert (current-buffer) t))
230 ;; For a mouse button event, go to the button it applies to
231 ;; to get the right key bindings. And go to the right place
232 ;; in case the keymap depends on where you clicked.
233 (if (or (memq 'click modifiers) (memq 'down modifiers)
234 (memq 'drag modifiers))
235 (setq window (posn-window (event-start (aref key 0)))
236 position (posn-point (event-start (aref key 0)))))
239 (set-buffer (window-buffer window))
240 (goto-char position)))
241 ;; Ok, now look up the key and name the command.
242 (let ((defn (or (mode-line-key-binding key)
244 (key-desc (key-description key)))
245 (if (or (null defn) (integerp defn))
246 (princ (format "%s is undefined" key-desc))
247 (princ (format (if insert
250 "%s at that spot runs the command %s"
251 "%s runs the command %s"))
253 (if (symbolp defn) defn (prin1-to-string defn)))))))))
255 (defvar help-return-method nil
256 "What to do to \"exit\" the help buffer.
258 (WINDOW . t) delete the selected window, go to WINDOW.
259 (WINDOW . quit-window) do quit-window, then select WINDOW.
260 (WINDOW BUF START POINT) display BUF at START, POINT, then select WINDOW.")
262 (defun print-help-return-message (&optional function)
263 "Display or return message saying how to restore windows after help command.
264 Computes a message and applies the optional argument FUNCTION to it.
265 If FUNCTION is nil, applies `message' to it, thus printing it."
266 (and (not (get-buffer-window standard-output))
268 (cond ((special-display-p (buffer-name standard-output))
269 (setq help-return-method (cons (selected-window) t))
270 ;; If the help output buffer is a special display buffer,
271 ;; don't say anything about how to get rid of it.
272 ;; First of all, the user will do that with the window
273 ;; manager, not with Emacs.
274 ;; Secondly, the buffer has not been displayed yet,
275 ;; so we don't know whether its frame will be selected.
277 (display-buffer-reuse-frames
278 (setq help-return-method (cons (selected-window)
281 ((not (one-window-p t))
282 (setq help-return-method
283 (cons (selected-window) 'quit-window))
284 "Type \\[switch-to-buffer-other-window] RET to restore the other window.")
286 (setq help-return-method (cons (selected-window) t))
287 "Type \\[delete-other-windows] to remove help window.")
289 (setq help-return-method
290 (list (selected-window) (window-buffer)
291 (window-start) (window-point)))
292 "Type \\[switch-to-buffer] RET to remove help window."))))
293 (funcall (or function 'message)
296 (substitute-command-keys first-message))
297 (if first-message " ")
298 ;; If the help buffer will go in a separate frame,
299 ;; it's no use mentioning a command to scroll, so don't.
300 (if (special-display-p (buffer-name standard-output))
302 (if (same-window-p (buffer-name standard-output))
303 ;; Say how to scroll this window.
304 (substitute-command-keys
305 "\\[scroll-up] to scroll the help.")
306 ;; Say how to scroll some other window.
307 (substitute-command-keys
308 "\\[scroll-other-window] to scroll the help."))))))))
310 (defun describe-key (key)
311 "Display documentation of the function invoked by KEY. KEY is a string."
312 (interactive "kDescribe key: ")
314 (let ((modifiers (event-modifiers (aref key 0)))
316 ;; For a mouse button event, go to the button it applies to
317 ;; to get the right key bindings. And go to the right place
318 ;; in case the keymap depends on where you clicked.
319 (if (or (memq 'click modifiers) (memq 'down modifiers)
320 (memq 'drag modifiers))
321 (setq window (posn-window (event-start (aref key 0)))
322 position (posn-point (event-start (aref key 0)))))
325 (set-buffer (window-buffer window))
326 (goto-char position)))
327 (let ((defn (or (mode-line-key-binding key) (key-binding key))))
328 (if (or (null defn) (integerp defn))
329 (message "%s is undefined" (key-description key))
330 (with-output-to-temp-buffer "*Help*"
331 (princ (key-description key))
333 (princ " at that spot"))
334 (princ " runs the command ")
336 (princ "\n which is ")
337 (describe-function-1 defn nil (interactive-p))
338 (print-help-return-message)))))))
340 (defun describe-mode ()
341 "Display documentation of current major mode and minor modes.
342 The major mode description comes first, followed by the minor modes,
343 each on a separate page.
345 For this to work correctly for a minor mode, the mode's indicator variable
346 \(listed in `minor-mode-alist') must also be a function whose documentation
347 describes the minor mode."
349 (with-output-to-temp-buffer "*Help*"
350 (when minor-mode-alist
351 (princ "The major mode is described first.
352 For minor modes, see following pages.\n\n"))
355 (princ (documentation major-mode))
356 (help-setup-xref (list #'help-xref-mode (current-buffer)) (interactive-p))
357 (let ((minor-modes minor-mode-alist))
359 (let* ((minor-mode (car (car minor-modes)))
360 (indicator (car (cdr (car minor-modes)))))
361 ;; Document a minor mode if it is listed in minor-mode-alist,
362 ;; bound locally in this buffer, non-nil, and has a function
364 (if (and (boundp minor-mode)
365 (symbol-value minor-mode)
366 (fboundp minor-mode))
367 (let ((pretty-minor-mode minor-mode))
368 (if (string-match "-mode$" (symbol-name minor-mode))
369 (setq pretty-minor-mode
371 (substring (symbol-name minor-mode)
372 0 (match-beginning 0)))))
373 (while (and indicator (symbolp indicator)
375 (not (eq indicator (symbol-value indicator))))
376 (setq indicator (symbol-value indicator)))
378 (princ (format "%s minor mode (%s):\n"
381 (format "indicator%s" indicator)
383 (princ (documentation minor-mode)))))
384 (setq minor-modes (cdr minor-modes))))
385 (print-help-return-message)))
387 ;; So keyboard macro definitions are documented correctly
388 (fset 'defining-kbd-macro (symbol-function 'start-kbd-macro))
390 (defun describe-distribution ()
391 "Display info on how to obtain the latest version of GNU Emacs."
394 (expand-file-name "DISTRIB" data-directory)))
396 (defun describe-copying ()
397 "Display info on how you may redistribute copies of GNU Emacs."
400 (expand-file-name "COPYING" data-directory))
401 (goto-char (point-min)))
403 (defun describe-project ()
404 "Display info on the GNU project."
407 (expand-file-name "THE-GNU-PROJECT" data-directory))
408 (goto-char (point-min)))
410 (defun describe-no-warranty ()
411 "Display info on all the kinds of warranty Emacs does NOT have."
414 (let (case-fold-search)
415 (search-forward "NO WARRANTY")
418 (defun describe-prefix-bindings ()
419 "Describe the bindings of the prefix used to reach this command.
420 The prefix described consists of all but the last event
421 of the key sequence that ran this command."
423 (let* ((key (this-command-keys)))
426 (substring key 0 (1- (length key)))
427 (let ((prefix (make-vector (1- (length key)) nil))
429 (while (< i (length prefix))
430 (aset prefix i (aref key i))
433 ;; Make C-h after a prefix, when not specifically bound,
434 ;; run describe-prefix-bindings.
435 (setq prefix-help-command 'describe-prefix-bindings)
437 (defun view-emacs-news (&optional arg)
438 "Display info on recent changes to Emacs.
439 With numeric argument, display information on correspondingly older changes."
441 (let* ((arg (if arg (prefix-numeric-value arg) 0))
442 (file (cond ((eq arg 0) "NEWS")
446 (nreverse (directory-files data-directory
447 nil "^ONEWS\\.[0-9]+$"
450 (find-file-read-only (expand-file-name file data-directory))
451 (error "No such old news"))))
453 (defun view-order-manuals ()
454 "Display the Emacs ORDERS file."
456 (find-file-read-only (expand-file-name "ORDERS" data-directory))
459 (defun view-emacs-FAQ ()
460 "Display the Emacs Frequently Asked Questions (FAQ) file."
462 ;;; (find-file-read-only (expand-file-name "FAQ" data-directory))
465 (defun view-emacs-problems ()
466 "Display info on known problems with Emacs and possible workarounds."
468 (view-file (expand-file-name "PROBLEMS" data-directory)))
470 (defun view-lossage ()
471 "Display last 100 input keystrokes."
473 (with-output-to-temp-buffer "*Help*"
474 (princ (mapconcat (function (lambda (key)
475 (if (or (integerp key)
478 (single-key-description key)
479 (prin1-to-string key nil))))
483 (set-buffer standard-output)
484 (goto-char (point-min))
485 (while (progn (move-to-column 50) (not (eobp)))
486 (search-forward " " nil t)
488 (setq help-xref-stack nil
489 help-xref-stack-item nil))
490 (print-help-return-message)))
492 (defalias 'help 'help-for-help)
493 (make-help-screen help-for-help
494 "a b c C f F C-f i I k C-k l L m n p s t v w C-c C-d C-n C-p C-w; ? for help:"
495 "You have typed %THIS-KEY%, the help character. Type a Help option:
496 \(Use SPC or DEL to scroll through this text. Type \\<help-map>\\[help-quit] to exit the Help command.)
498 a command-apropos. Give a substring, and see a list of commands
499 (functions interactively callable) that contain
500 that substring. See also the apropos command.
501 b describe-bindings. Display table of all key bindings.
502 c describe-key-briefly. Type a command key sequence;
503 it prints the function name that sequence runs.
504 C describe-coding-system. This describes either a specific coding system
505 (if you type its name) or the coding systems currently in use
506 (if you type just RET).
507 f describe-function. Type a function name and get documentation of it.
508 C-f Info-goto-emacs-command-node. Type a function name;
509 it takes you to the Info node for that command.
510 i info. The info documentation reader.
511 I describe-input-method. Describe a specific input method (if you type
512 its name) or the current input method (if you type just RET).
513 C-i info-lookup-symbol. Display the definition of a specific symbol
514 as found in the manual for the language this buffer is written in.
515 k describe-key. Type a command key sequence;
516 it displays the full documentation.
517 C-k Info-goto-emacs-key-command-node. Type a command key sequence;
518 it takes you to the Info node for the command bound to that key.
519 l view-lossage. Show last 100 characters you typed.
520 L describe-language-environment. This describes either a
521 specific language environment (if you type its name)
522 or the current language environment (if you type just RET).
523 m describe-mode. Print documentation of current minor modes,
524 and the current major mode, including their special commands.
525 n view-emacs-news. Display news of recent Emacs changes.
526 p finder-by-keyword. Find packages matching a given topic keyword.
527 s describe-syntax. Display contents of syntax table, plus explanations
528 t help-with-tutorial. Select the Emacs learn-by-doing tutorial.
529 v describe-variable. Type name of a variable;
530 it displays the variable's documentation and value.
531 w where-is. Type command name; it prints which keystrokes
534 F Display the frequently asked questions file.
535 h Display the HELLO file which illustrates various scripts.
536 C-c Display Emacs copying permission (General Public License).
537 C-d Display Emacs ordering information.
538 C-n Display news of recent Emacs changes.
539 C-p Display information about the GNU project.
540 C-w Display information on absence of warranty for GNU Emacs."
543 (defun function-called-at-point ()
544 "Return a function around point or else called by the list containing point.
545 If that doesn't give a function, return nil."
546 (with-syntax-table emacs-lisp-mode-syntax-table
547 (or (condition-case ()
549 (or (not (zerop (skip-syntax-backward "_w")))
550 (eq (char-syntax (following-char)) ?w)
551 (eq (char-syntax (following-char)) ?_)
553 (skip-chars-forward "'")
554 (let ((obj (read (current-buffer))))
555 (and (symbolp obj) (fboundp obj) obj)))
560 (narrow-to-region (max (point-min)
561 (- (point) 1000)) (point-max))
562 ;; Move up to surrounding paren, then after the open.
565 ;; If there is space here, this is probably something
566 ;; other than a real Lisp function call, so ignore it.
567 (if (looking-at "[ \t]")
568 (error "Probably not a Lisp function call"))
569 (let ((obj (read (current-buffer))))
570 (and (symbolp obj) (fboundp obj) obj))))
573 (defvar symbol-file-load-history-loaded nil
574 "Non-nil means we have loaded the file `fns-VERSION.el' in `exec-directory'.
575 That file records the part of `load-history' for preloaded files,
576 which is cleared out before dumping to make Emacs smaller.")
578 (defun load-symbol-file-load-history ()
579 "Load the file `fns-VERSION.el' in `exec-directory' if not already done.
580 That file records the part of `load-history' for preloaded files,
581 which is cleared out before dumping to make Emacs smaller."
582 (unless symbol-file-load-history-loaded
583 (load (expand-file-name
584 ;; fns-XX.YY.ZZ.el does not work on DOS filesystem.
585 (if (eq system-type 'ms-dos)
587 (format "fns-%s.el" emacs-version))
589 ;; The file name fns-%s.el already has a .el extension.
591 (setq symbol-file-load-history-loaded t)))
593 (defun symbol-file (function)
594 "Return the input source from which FUNCTION was loaded.
595 The value is normally a string that was passed to `load':
596 either an absolute file name, or a library name
597 \(with no directory name and no `.el' or `.elc' at the end).
598 It can also be nil, if the definition is not associated with any file."
599 (load-symbol-file-load-history)
600 (let ((files load-history)
603 (if (memq function (cdr (car files)))
604 (setq file (car (car files)) files nil))
605 (setq files (cdr files)))
608 (defun describe-function (function)
609 "Display the full documentation of FUNCTION (a symbol)."
611 (let ((fn (function-called-at-point))
612 (enable-recursive-minibuffers t)
614 (setq val (completing-read (if fn
615 (format "Describe function (default %s): " fn)
616 "Describe function: ")
617 obarray 'fboundp t nil nil (symbol-name fn)))
618 (list (if (equal val "")
621 (with-output-to-temp-buffer "*Help*"
623 ;; Use " is " instead of a colon so that
624 ;; it is easier to get out the function name using forward-sexp.
626 (describe-function-1 function nil (interactive-p))
627 (print-help-return-message)
629 (set-buffer standard-output)
630 ;; Return the text we displayed.
632 (message "You didn't specify a function")))
634 (defun describe-function-1 (function parens interactive-p)
635 (let* ((def (if (symbolp function)
636 (symbol-function function)
638 file-name string need-close
639 (beg (if (commandp def) "an interactive " "a ")))
641 (cond ((or (stringp def)
645 (if (eq 'unevalled (cdr (subr-arity def)))
646 (concat beg "special form")
647 (concat beg "built-in function")))
648 ((byte-code-function-p def)
649 (concat beg "compiled Lisp function"))
651 (while (symbolp (symbol-function def))
652 (setq def (symbol-function def)))
653 (format "an alias for `%s'" def))
654 ((eq (car-safe def) 'lambda)
655 (concat beg "Lisp function"))
656 ((eq (car-safe def) 'macro)
658 ((eq (car-safe def) 'mocklisp)
659 "a mocklisp function")
660 ((eq (car-safe def) 'autoload)
661 (setq file-name (nth 1 def))
662 (format "%s autoloaded %s"
663 (if (commandp def) "an interactive" "an")
664 (if (eq (nth 4 def) 'keymap) "keymap"
665 (if (nth 4 def) "Lisp macro" "Lisp function"))
667 ;; perhaps use keymapp here instead
668 ((eq (car-safe def) 'keymap)
670 (elts (cdr-safe def)))
672 (if (char-table-p (car-safe elts))
675 (setq elts (cdr-safe elts)))
680 (when (and parens (not (equal string "")))
684 (with-current-buffer "*Help*"
687 (if (re-search-backward "alias for `\\([^`']+\\)'" nil t)
688 (help-xref-button 1 #'describe-function def
689 "mouse-2, RET: describe this function")))))
691 (setq file-name (symbol-file function)))
695 ;; We used to add .el to the file name,
696 ;; but that's completely wrong when the user used load-file.
699 ;; Make a hyperlink to the library.
700 (with-current-buffer "*Help*"
702 (re-search-backward "`\\([^`']+\\)'" nil t)
703 (help-xref-button 1 #'(lambda (arg)
705 (find-function-noselect arg)))
706 (pop-to-buffer (car location))
707 (goto-char (cdr location))))
709 "mouse-2, RET: find function's definition")))))
710 (if need-close (princ ")"))
713 ;; Handle symbols aliased to other symbols.
714 (setq def (indirect-function def))
715 ;; If definition is a macro, find the function inside it.
716 (if (eq (car-safe def) 'macro)
717 (setq def (cdr def)))
718 (let ((arglist (cond ((byte-code-function-p def)
719 (car (append def nil)))
720 ((eq (car-safe def) 'lambda)
722 ((and (eq (car-safe def) 'autoload)
723 (not (eq (nth 4 def) 'keymap)))
724 (concat "[Arg list not available until "
725 "function definition is loaded.]"))
727 (cond ((listp arglist)
728 (princ (cons (if (symbolp function) function "anonymous")
729 (mapcar (lambda (arg)
730 (if (memq arg '(&optional &rest))
732 (intern (upcase (symbol-name arg)))))
738 (let ((doc (documentation function)))
742 (if (subrp (symbol-function function))
743 (with-current-buffer standard-output
745 ;; Builtins get the calling sequence at the end of
746 ;; the doc string. Move it to the same place as
747 ;; for other functions.
749 ;; In cases where `function' has been fset to a
750 ;; subr we can't search for function's name in
751 ;; the doc string. Kluge round that using the
752 ;; printed representation. The arg list then
753 ;; shows the wrong function name, but that
754 ;; might be a useful hint.
755 (let* ((rep (prin1-to-string def))
757 (string-match " \\([^ ]+\\)>$" rep)
758 (match-string 1 rep))))
759 (if (looking-at (format "(%s[ )]" (regexp-quote name)))
760 (let ((start (point-marker)))
761 (goto-char (point-min))
763 (insert-buffer-substring (current-buffer) start)
765 (delete-region (1- start) (point-max)))
766 (goto-char (point-min))
769 "[Missing arglist. Please make a bug report.]\n")))
770 (goto-char (point-max))))
771 (help-setup-xref (list #'describe-function function)
773 (princ "not documented")))))
775 (defun variable-at-point ()
776 "Return the bound variable symbol found around point.
777 Return 0 if there is no such symbol."
779 (with-syntax-table emacs-lisp-mode-syntax-table
781 (or (not (zerop (skip-syntax-backward "_w")))
782 (eq (char-syntax (following-char)) ?w)
783 (eq (char-syntax (following-char)) ?_)
785 (skip-chars-forward "'")
786 (let ((obj (read (current-buffer))))
787 (or (and (symbolp obj) (boundp obj) obj)
791 (defun help-xref-on-pp (from to)
792 "Add xrefs for symbols in `pp's output between FROM and TO."
793 (let ((ost (syntax-table)))
797 (set-syntax-table emacs-lisp-mode-syntax-table)
798 (narrow-to-region from to)
799 (goto-char (point-min))
802 ((looking-at "\"") (forward-sexp 1))
803 ((looking-at "#<") (search-forward ">" nil 'move))
804 ((looking-at "\\(\\(\\sw\\|\\s_\\)+\\)")
805 (let* ((sym (intern-soft (match-string 1)))
806 (fn (cond ((fboundp sym) #'describe-function)
807 ((or (memq sym '(t nil))
810 ((and sym (boundp sym))
811 #'describe-variable))))
812 (when fn (help-xref-button 1 fn sym)))
813 (goto-char (match-end 1)))
814 (t (forward-char 1))))))
815 (set-syntax-table ost))))
817 (defun describe-variable (variable &optional buffer)
818 "Display the full documentation of VARIABLE (a symbol).
819 Returns the documentation as a string, also.
820 If VARIABLE has a buffer-local value in BUFFER (default to the current buffer),
821 it is displayed along with the global value."
823 (let ((v (variable-at-point))
824 (enable-recursive-minibuffers t)
826 (setq val (completing-read (if (symbolp v)
828 "Describe variable (default %s): " v)
829 "Describe variable: ")
830 obarray 'boundp t nil nil
831 (if (symbolp v) (symbol-name v))))
832 (list (if (equal val "")
834 (unless (bufferp buffer) (setq buffer (current-buffer)))
835 (if (not (symbolp variable))
836 (message "You did not specify a variable")
838 (with-current-buffer buffer
839 (with-output-to-temp-buffer "*Help*"
841 (if (not (boundp variable))
845 (let ((val (symbol-value variable)))
846 (with-current-buffer standard-output
847 (princ "'s value is ")
849 (let ((from (point)))
851 (help-xref-on-pp from (point))))))
853 (if (local-variable-p variable)
855 (princ (format "Local in buffer %s; " (buffer-name)))
856 (if (not (default-boundp variable))
857 (princ "globally void")
858 (let ((val (default-value variable)))
859 (with-current-buffer standard-output
860 (princ "global value is ")
862 ;; Fixme: pp can take an age if you happen to
863 ;; ask for a very large expression. We should
864 ;; probably print it raw once and check it's a
865 ;; sensible size before prettyprinting. -- fx
866 (let ((from (point)))
868 (help-xref-on-pp from (point))))))
871 (with-current-buffer standard-output
872 (if (> (count-lines (point-min) (point-max)) 10)
874 ;; Note that setting the syntax table like below
875 ;; makes forward-sexp move over a `'s' at the end
877 (set-syntax-table emacs-lisp-mode-syntax-table)
878 (goto-char (point-min))
882 (delete-region (point) (progn (end-of-line) (point)))
883 (insert " value is shown below.\n\n")
885 (insert "\n\nValue:"))))))
886 (princ "Documentation:")
888 (let ((doc (documentation-property variable 'variable-documentation)))
889 (princ (or doc "not documented as a variable.")))
890 (help-setup-xref (list #'describe-variable variable (current-buffer))
893 ;; Make a link to customize if this variable can be customized.
894 ;; Note, it is not reliable to test only for a custom-type property
895 ;; because those are only present after the var's definition
897 (if (or (get variable 'custom-type) ; after defcustom
898 (get variable 'custom-loads) ; from loaddefs.el
899 (get variable 'standard-value)) ; from cus-start.el
900 (let ((customize-label "customize"))
903 (princ (concat "You can " customize-label " this variable."))
904 (with-current-buffer "*Help*"
907 (concat "\\(" customize-label "\\)") nil t)
908 (help-xref-button 1 (lambda (v)
910 (pop help-xref-stack))
911 (customize-variable v))
913 "mouse-2, RET: customize variable")))))
914 ;; Make a hyperlink to the library if appropriate. (Don't
915 ;; change the format of the buffer's initial line in case
916 ;; anything expects the current format.)
917 (let ((file-name (symbol-file variable)))
919 (princ "\n\nDefined in `")
922 (with-current-buffer "*Help*"
924 (re-search-backward "`\\([^`']+\\)'" nil t)
928 (find-variable-noselect arg)))
929 (pop-to-buffer (car location))
930 (goto-char (cdr location))))
931 variable "mouse-2, RET: find variable's definition")))))
933 (print-help-return-message)
935 (set-buffer standard-output)
936 ;; Return the text we displayed.
937 (buffer-string)))))))
939 (defun describe-bindings (&optional prefix buffer)
940 "Show a list of all defined keys, and their definitions.
941 We put that list in a buffer, and display the buffer.
943 The optional argument PREFIX, if non-nil, should be a key sequence;
944 then we display only bindings that start with that prefix.
945 The optional argument BUFFER specifies which buffer's bindings
946 to display (default, the current buffer)."
948 (or buffer (setq buffer (current-buffer)))
949 (with-current-buffer buffer
950 (describe-bindings-internal nil prefix))
951 (with-current-buffer "*Help*"
952 (help-setup-xref (list #'describe-bindings prefix buffer)
955 (defun where-is (definition &optional insert)
956 "Print message listing key sequences that invoke the command DEFINITION.
957 Argument is a command definition, usually a symbol with a function definition.
958 If INSERT (the prefix arg) is non-nil, insert the message in the buffer."
960 (let ((fn (function-called-at-point))
961 (enable-recursive-minibuffers t)
963 (setq val (completing-read (if fn
964 (format "Where is command (default %s): " fn)
965 "Where is command: ")
966 obarray 'commandp t))
967 (list (if (equal val "")
969 current-prefix-arg)))
970 (let* ((keys (where-is-internal definition overriding-local-map nil nil))
971 (keys1 (mapconcat 'key-description keys ", "))
972 (standard-output (if insert (current-buffer) t)))
974 (if (> (length keys1) 0)
975 (princ (format "%s (%s)" keys1 definition))
976 (princ (format "M-x %s RET" definition)))
977 (if (> (length keys1) 0)
978 (princ (format "%s is on %s" definition keys1))
979 (princ (format "%s is not on any key" definition)))))
982 (defun locate-library (library &optional nosuffix path interactive-call)
983 "Show the precise file name of Emacs library LIBRARY.
984 This command searches the directories in `load-path' like `M-x load-library'
985 to find the file that `M-x load-library RET LIBRARY RET' would load.
986 Optional second arg NOSUFFIX non-nil means don't add suffixes `.elc' or `.el'
987 to the specified name LIBRARY.
989 If the optional third arg PATH is specified, that list of directories
990 is used instead of `load-path'.
992 When called from a program, the file name is normaly returned as a
993 string. When run interactively, the argument INTERACTIVE-CALL is t,
994 and the file name is displayed in the echo area."
995 (interactive (list (read-string "Locate library: ")
1004 (let ((try (expand-file-name (concat library suf) dir)))
1005 (and (file-readable-p try)
1006 (null (file-directory-p try))
1009 (throw 'answer try)))))
1013 ;;; load doesn't handle this yet.
1014 ;;; (let ((basic '(".elc" ".el" ""))
1015 ;;; (compressed '(".Z" ".gz" "")))
1016 ;;; ;; If autocompression mode is on,
1017 ;;; ;; consider all combinations of library suffixes
1018 ;;; ;; and compression suffixes.
1019 ;;; (if (rassq 'jka-compr-handler file-name-handler-alist)
1021 ;;; (mapcar (lambda (compelt)
1022 ;;; (mapcar (lambda (baselt)
1023 ;;; (concat baselt compelt))
1028 (or path load-path)))
1029 (and interactive-call
1031 (message "Library is file %s" result)
1032 (message "No library %s in search path" library)))
1036 ;;; Grokking cross-reference information in doc strings and
1037 ;;; hyperlinking it.
1039 ;; This may have some scope for extension and the same or something
1040 ;; similar should be done for widget doc strings, which currently use
1041 ;; another mechanism.
1043 (defcustom help-highlight-p t
1044 "*If non-nil, `help-make-xrefs' highlight cross-references.
1045 Under a window system it highlights them with face defined by
1046 `help-highlight-face'."
1051 (defcustom help-highlight-face 'underline
1052 "Face used by `help-make-xrefs' to highlight cross-references.
1053 Must be previously-defined."
1058 (defvar help-back-label (purecopy "[back]")
1059 "Label to use by `help-make-xrefs' for the go-back reference.")
1061 (defconst help-xref-symbol-regexp
1062 (purecopy (concat "\\(\\<\\(\\(variable\\|option\\)\\|"
1063 "\\(function\\|command\\)\\|"
1065 "\\(symbol\\)\\)\\s-+\\)?"
1066 ;; Note starting with word-syntax character:
1067 "`\\(\\sw\\(\\sw\\|\\s_\\)+\\)'"))
1068 "Regexp matching doc string references to symbols.
1070 The words preceding the quoted symbol can be used in doc strings to
1071 distinguish references to variables, functions and symbols.")
1073 (defconst help-xref-mule-regexp nil
1074 "Regexp matching doc string references to MULE-related keywords.
1076 It is usually nil, and is temporarily bound to an appropriate regexp
1077 when help commands related to multilingual environment (e.g.,
1078 `describe-coding-system') are invoked.")
1081 (defconst help-xref-info-regexp
1082 (purecopy "\\<[Ii]nfo[ \t\n]+node[ \t\n]+`\\([^']+\\)'")
1083 "Regexp matching doc string references to an Info node.")
1085 (defun help-setup-xref (item interactive-p)
1086 "Invoked from commands using the \"*Help*\" buffer to install some xref info.
1088 ITEM is a (FUNCTION . ARGS) pair appropriate for recreating the help
1089 buffer after following a reference. INTERACTIVE-P is non-nil if the
1090 calling command was invoked interactively. In this case the stack of
1091 items for help buffer \"back\" buttons is cleared."
1093 (setq help-xref-stack nil))
1094 (setq help-xref-stack-item item))
1096 (defvar help-xref-following nil
1097 "Non-nil when following a help cross-reference.")
1099 (defun help-make-xrefs (&optional buffer)
1100 "Parse and hyperlink documentation cross-references in the given BUFFER.
1102 Find cross-reference information in a buffer and, if
1103 `help-highlight-p' is non-nil, highlight it with face defined by
1104 `help-highlight-face'; activate such cross references for selection
1105 with `help-follow'. Cross-references have the canonical form `...'
1106 and the type of reference may be disambiguated by the preceding
1107 word(s) used in `help-xref-symbol-regexp'.
1109 If the variable `help-xref-mule-regexp' is non-nil, find also
1110 cross-reference information related to multilingual environment
1111 \(e.g., coding-systems). This variable is also used to disambiguate
1112 the type of reference as the same way as `help-xref-symbol-regexp'.
1114 A special reference `back' is made to return back through a stack of
1115 help buffers. Variable `help-back-label' specifies the text for
1119 (set-buffer (or buffer (current-buffer)))
1120 (goto-char (point-min))
1121 ;; Skip the header-type info, though it might be useful to parse
1122 ;; it at some stage (e.g. "function in `library'").
1124 (let ((old-modified (buffer-modified-p)))
1125 (let ((stab (syntax-table))
1126 (case-fold-search t)
1127 (inhibit-read-only t))
1128 (set-syntax-table emacs-lisp-mode-syntax-table)
1129 ;; The following should probably be abstracted out.
1134 (while (re-search-forward help-xref-info-regexp nil t)
1135 (let ((data (match-string 1)))
1137 (unless (string-match "^([^)]+)" data)
1138 (setq data (concat "(emacs)" data))))
1139 (help-xref-button 1 #'info data
1140 "mouse-2, RET: read this Info node"))))
1141 ;; Mule related keywords. Do this before trying
1142 ;; `help-xref-symbol-regexp' because some of Mule
1143 ;; keywords have variable or function definitions.
1144 (if help-xref-mule-regexp
1146 (while (re-search-forward help-xref-mule-regexp nil t)
1147 (let* ((data (match-string 7))
1148 (sym (intern-soft data)))
1150 ((match-string 3) ; coding system
1151 (and sym (coding-system-p sym)
1153 7 #'describe-coding-system sym
1154 "mouse-2, RET: describe this coding system")))
1155 ((match-string 4) ; input method
1156 (and (assoc data input-method-alist)
1158 7 #'describe-input-method data
1159 "mouse-2, RET: describe this input method")))
1160 ((or (match-string 5) (match-string 6)) ; charset
1161 (and sym (charsetp sym)
1163 7 #'describe-character-set sym
1164 "mouse-2, RET: describe this character set")))
1165 ((assoc data input-method-alist)
1167 7 #'describe-input-method data
1168 "mouse-2, RET: describe this input method"))
1169 ((and sym (coding-system-p sym))
1171 7 #'describe-coding-system sym
1172 "mouse-2, RET: describe this coding system"))
1173 ((and sym (charsetp sym))
1175 7 #'describe-character-set sym
1176 "mouse-2, RET: describe this character set")))))))
1179 (while (re-search-forward help-xref-symbol-regexp nil t)
1180 (let* ((data (match-string 7))
1181 (sym (intern-soft data)))
1184 ((match-string 3) ; `variable' &c
1185 (and (boundp sym) ; `variable' doesn't ensure
1186 ; it's actually bound
1188 7 #'describe-variable sym
1189 "mouse-2, RET: describe this variable")))
1190 ((match-string 4) ; `function' &c
1191 (and (fboundp sym) ; similarly
1193 7 #'describe-function sym
1194 "mouse-2, RET: describe this function")))
1195 ((match-string 5) ; `face'
1197 (help-xref-button 7 #'describe-face sym
1198 "mouse-2, RET: describe this face")))
1199 ((match-string 6)) ; nothing for symbol
1200 ((and (boundp sym) (fboundp sym))
1201 ;; We can't intuit whether to use the
1202 ;; variable or function doc -- supply both.
1204 7 #'help-xref-interned sym
1205 "mouse-2, RET: describe this symbol"))
1208 7 #'describe-variable sym
1209 "mouse-2, RET: describe this variable"))
1212 7 #'describe-function sym
1213 "mouse-2, RET: describe this function"))
1216 7 #'describe-face sym)))))))
1217 ;; An obvious case of a key substitution:
1219 (while (re-search-forward
1220 ;; Assume command name is only word characters
1221 ;; and dashes to get things like `use M-x foo.'.
1222 "\\<M-x\\s-+\\(\\sw\\(\\sw\\|-\\)+\\)" nil t)
1223 (let ((sym (intern-soft (match-string 1))))
1226 1 #'describe-function sym
1227 "mouse-2, RET: describe this command")))))
1228 ;; Look for commands in whole keymap substitutions:
1230 ;; Make sure to find the first keymap.
1231 (goto-char (point-min))
1232 ;; Find a header and the column at which the command
1233 ;; name will be found.
1234 (while (re-search-forward "^key +binding\n\\(-+ +\\)-+\n\n"
1236 (let ((col (- (match-end 1) (match-beginning 1))))
1238 ;; Ignore single blank lines in table, but not
1239 ;; double ones, which should terminate it.
1240 (and (not (looking-at "\n\\s-*\n"))
1242 (and (eolp) (forward-line))
1244 (skip-chars-backward "^\t\n")
1245 (if (and (>= (current-column) col)
1246 (looking-at "\\(\\sw\\|-\\)+$"))
1247 (let ((sym (intern-soft (match-string 0))))
1250 0 #'describe-function sym
1251 "mouse-2, RET: describe this function"))))
1252 (zerop (forward-line)))))))))
1253 (set-syntax-table stab))
1254 ;; Delete extraneous newlines at the end of the docstring
1255 (goto-char (point-max))
1256 (while (and (not (bobp)) (bolp))
1258 ;; Make a back-reference in this buffer if appropriate.
1259 (when (and help-xref-following help-xref-stack)
1261 (insert "\n\n" help-back-label))
1262 ;; Just to provide the match data:
1263 (looking-at (concat "\n\n\\(" (regexp-quote help-back-label) "\\)"))
1264 (help-xref-button 1 #'help-xref-go-back (current-buffer))))
1265 ;; View mode steals RET from us.
1266 (set (make-local-variable 'minor-mode-overriding-map-alist)
1267 (list (cons 'view-mode
1268 (let ((map (make-sparse-keymap)))
1269 (set-keymap-parent map view-mode-map)
1270 (define-key map "\r" 'help-follow)
1272 (set-buffer-modified-p old-modified))))
1274 (defun help-xref-button (match-number function data &optional help-echo)
1275 "Make a hyperlink for cross-reference text previously matched.
1277 MATCH-NUMBER is the subexpression of interest in the last matched
1278 regexp. FUNCTION is a function to invoke when the button is
1279 activated, applied to DATA. DATA may be a single value or a list.
1280 See `help-make-xrefs'.
1281 If optional arg HELP-ECHO is supplied, it is used as a help string."
1282 ;; Don't mung properties we've added specially in some instances.
1283 (unless (get-text-property (match-beginning match-number) 'help-xref)
1284 (add-text-properties (match-beginning match-number)
1285 (match-end match-number)
1286 (list 'mouse-face 'highlight
1287 'help-xref (cons function
1292 (put-text-property (match-beginning match-number)
1293 (match-end match-number)
1294 'help-echo help-echo))
1295 (if help-highlight-p
1296 (put-text-property (match-beginning match-number)
1297 (match-end match-number)
1298 'face help-highlight-face))))
1300 (defun help-insert-xref-button (string function data &optional help-echo)
1301 "Insert STRING and make a hyperlink from cross-reference text on it.
1303 FUNCTION is a function to invoke when the button is activated, applied
1304 to DATA. DATA may be a single value or a list. See `help-make-xrefs'.
1305 If optional arg HELP-ECHO is supplied, it is used as a help string."
1306 (let ((pos (point)))
1309 (search-forward string)
1310 (help-xref-button 0 function data help-echo)))
1314 ;; Additional functions for (re-)creating types of help buffers.
1315 (defun help-xref-interned (symbol)
1316 "Follow a hyperlink which appeared to be an arbitrary interned SYMBOL.
1318 Both variable and function documentation are extracted into a single
1320 (let ((fdoc (when (fboundp symbol) (describe-function symbol)))
1321 (facedoc (when (facep symbol) (describe-face symbol))))
1322 (when (or (boundp symbol) (not fdoc))
1323 (describe-variable symbol)
1324 ;; We now have a help buffer on the variable. Insert the function
1326 (when (or fdoc facedoc)
1327 (with-current-buffer "*Help*"
1328 (goto-char (point-min))
1329 (let ((inhibit-read-only t))
1331 (insert fdoc "\n\n"))
1333 (insert (make-string 30 ?-) "\n\n" (symbol-name symbol)
1334 " is also a " "face." "\n\n" facedoc "\n\n"))
1335 (insert (make-string 30 ?-) "\n\n" (symbol-name symbol)
1336 " is also a " "variable." "\n\n"))
1337 (help-setup-xref (list #'help-xref-interned symbol) nil))))))
1339 (defun help-xref-mode (buffer)
1340 "Do a `describe-mode' for the specified BUFFER."
1345 ;;; Navigation/hyperlinking with xrefs
1347 (defun help-follow-mouse (click)
1348 "Follow the cross-reference that you click on."
1350 (let* ((start (event-start click))
1351 (window (car start))
1352 (pos (car (cdr start))))
1353 (with-current-buffer (window-buffer window)
1354 (help-follow pos))))
1356 (defun help-xref-go-back (buffer)
1357 "From BUFFER, go back to previous help buffer text using `help-xref-stack'."
1358 (let (item position method args)
1359 (with-current-buffer buffer
1360 (when help-xref-stack
1361 (setq help-xref-stack (cdr help-xref-stack)) ; due to help-follow
1362 (setq item (pop help-xref-stack)
1367 ;; We assume that the buffer we just recreated has the saved name,
1368 ;; which might not always be true.
1369 (when (get-buffer (cdr position))
1370 (with-current-buffer (cdr position)
1371 (goto-char (car position))))))
1373 (defun help-go-back ()
1374 "Invoke the [back] button (if any) in the Help mode buffer."
1376 (help-follow (1- (point-max))))
1378 (defun help-follow (&optional pos)
1379 "Follow cross-reference at POS, defaulting to point.
1381 For the cross-reference format, see `help-make-xrefs'."
1386 (or (and (not (= pos (point-max)))
1387 (get-text-property pos 'help-xref))
1388 (and (not (= pos (point-min)))
1389 (get-text-property (1- pos) 'help-xref))
1390 ;; check if the symbol under point is a function or variable
1394 (goto-char pos) (skip-syntax-backward "w_")
1395 (buffer-substring (point)
1396 (progn (skip-syntax-forward "w_")
1398 (when (or (boundp sym) (fboundp sym))
1399 (list #'help-xref-interned sym)))))
1400 (method (car help-data))
1401 (args (cdr help-data)))
1403 (setq help-xref-stack (cons (cons (cons pos (buffer-name))
1404 help-xref-stack-item)
1406 (setq help-xref-stack-item nil)
1407 ;; There is a reference at point. Follow it.
1408 (let ((help-xref-following t))
1409 (apply method args)))))
1411 ;; For tabbing through buffer.
1412 (defun help-next-ref ()
1413 "Find the next help cross-reference in the buffer."
1417 (if (get-text-property (point) 'help-xref) ; move off reference
1418 (goto-char (or (next-single-property-change (point) 'help-xref)
1420 (cond ((setq pos (next-single-property-change (point) 'help-xref))
1421 (if pos (goto-char pos)))
1423 (message "No cross references in the buffer.")
1426 (goto-char (point-min)))))))
1428 (defun help-previous-ref ()
1429 "Find the previous help cross-reference in the buffer."
1433 (if (get-text-property (point) 'help-xref) ; move off reference
1434 (goto-char (or (previous-single-property-change (point) 'help-xref)
1436 (cond ((setq pos (previous-single-property-change (point) 'help-xref))
1437 (if pos (goto-char pos)))
1439 (message "No cross references in the buffer.")
1442 (goto-char (point-max)))))))
1445 ;;; Automatic resizing of temporary buffers.
1447 (defcustom temp-buffer-max-height (lambda (buffer) (/ (- (frame-height) 2) 2))
1448 "*Maximum height of a window displaying a temporary buffer.
1449 This is the maximum height (in text lines) which `resize-temp-buffer-window'
1450 will give to a window displaying a temporary buffer.
1451 It can also be a function which will be called with the object corresponding
1452 to the buffer to be displayed as argument and should return an integer
1454 :type '(choice integer function)
1458 (define-minor-mode temp-buffer-resize-mode
1459 "Toggle the mode which makes windows smaller for temporary buffers.
1460 With prefix argument ARG, turn the resizing of windows displaying temporary
1461 buffers on if ARG is positive or off otherwise.
1462 This makes the window the right height for its contents, but never
1463 more than `temp-buffer-max-height' nor less than `window-min-height'.
1464 This applies to `help', `apropos' and `completion' buffers, and some others."
1465 nil nil nil :global t :group 'help
1466 (if temp-buffer-resize-mode
1467 ;; `help-make-xrefs' may add a `back' button and thus increase the
1468 ;; text size, so `resize-temp-buffer-window' must be run *after* it.
1469 (add-hook 'temp-buffer-show-hook 'resize-temp-buffer-window 'append)
1470 (remove-hook 'temp-buffer-show-hook 'resize-temp-buffer-window)))
1472 (defun resize-temp-buffer-window ()
1473 "Resize the current window to fit its contents.
1474 Will not make it higher than `temp-buffer-max-height' nor smaller than
1475 `window-min-height'. Do nothing if it is the only window on its frame, if it
1476 is not as wide as the frame or if some of the window's contents are scrolled
1478 (unless (or (one-window-p 'nomini)
1479 (not (pos-visible-in-window-p (point-min)))
1480 (/= (frame-width) (window-width)))
1481 (fit-window-to-buffer
1483 (if (functionp temp-buffer-max-height)
1484 (funcall temp-buffer-max-height (current-buffer))
1485 temp-buffer-max-height))))
1487 ;; `help-manyarg-func-alist' is defined primitively (in doc.c).
1488 ;; New primitives with `MANY' or `UNEVALLED' arglists should be added
1490 ;; The parens and function name are redundant, but it's messy to add
1491 ;; them in `documentation'.
1493 ;; This will find any missing items:
1495 ;; (mapatoms (lambda (x)
1496 ;; (if (and (fboundp x)
1497 ;; (subrp (symbol-function x))
1498 ;; (not (numberp (cdr (subr-arity (symbol-function x)))))
1499 ;; (not (assq x help-manyarg-func-alist)))
1502 (defconst help-manyarg-func-alist
1504 '((list . "(list &rest OBJECTS)")
1505 (vector . "(vector &rest OBJECTS)")
1506 (make-byte-code . "(make-byte-code &rest ELEMENTS)")
1508 . "(call-process PROGRAM &optional INFILE BUFFER DISPLAY &rest ARGS)")
1509 (call-process-region
1510 . "(call-process-region START END PROGRAM &optional DELETE BUFFER DISPLAY &rest ARGS)")
1511 (string . "(string &rest CHARACTERS)")
1512 (+ . "(+ &rest NUMBERS-OR-MARKERS)")
1513 (- . "(- &optional NUMBER-OR-MARKER &rest MORE-NUMBERS-OR-MARKERS)")
1514 (* . "(* &rest NUMBERS-OR-MARKERS)")
1515 (/ . "(/ DIVIDEND DIVISOR &rest DIVISORS)")
1516 (max . "(max NUMBER-OR-MARKER &rest NUMBERS-OR-MARKERS)")
1517 (min . "(min NUMBER-OR-MARKER &rest NUMBERS-OR-MARKERS)")
1518 (logand . "(logand &rest INTS-OR-MARKERS)")
1519 (logior . "(logior &rest INTS-OR-MARKERS)")
1520 (logxor . "(logxor &rest INTS-OR-MARKERS)")
1522 . "(encode-time SECOND MINUTE HOUR DAY MONTH YEAR &optional ZONE)")
1523 (insert . "(insert &rest ARGS)")
1524 (insert-and-inherit . "(insert-and-inherit &rest ARGS)")
1525 (insert-before-markers . "(insert-before-markers &rest ARGS)")
1526 (message . "(message STRING &rest ARGUMENTS)")
1527 (message-box . "(message-box STRING &rest ARGUMENTS)")
1528 (message-or-box . "(message-or-box STRING &rest ARGUMENTS)")
1529 (propertize . "(propertize STRING &rest PROPERTIES)")
1530 (format . "(format STRING &rest OBJECTS)")
1531 (apply . "(apply FUNCTION &rest ARGUMENTS)")
1532 (run-hooks . "(run-hooks &rest HOOKS)")
1533 (run-hook-with-args . "(run-hook-with-args HOOK &rest ARGS)")
1534 (run-hook-with-args-until-failure
1535 . "(run-hook-with-args-until-failure HOOK &rest ARGS)")
1536 (run-hook-with-args-until-success
1537 . "(run-hook-with-args-until-success HOOK &rest ARGS)")
1538 (funcall . "(funcall FUNCTION &rest ARGUMENTS)")
1539 (append . "(append &rest SEQUENCES)")
1540 (concat . "(concat &rest SEQUENCES)")
1541 (vconcat . "(vconcat &rest SEQUENCES)")
1542 (nconc . "(nconc &rest LISTS)")
1543 (widget-apply . "(widget-apply WIDGET PROPERTY &rest ARGS)")
1544 (make-hash-table . "(make-hash-table &rest KEYWORD-ARGS)")
1545 (insert-string . "(insert-string &rest ARGS)")
1546 (start-process . "(start-process NAME BUFFER PROGRAM &rest PROGRAM-ARGS)")
1547 (setq-default . "(setq-default SYMBOL VALUE [SYMBOL VALUE...])")
1548 (save-excursion . "(save-excursion &rest BODY)")
1549 (save-current-buffer . "(save-current-buffer &rest BODY)")
1550 (save-restriction . "(save-restriction &rest BODY)")
1551 (or . "(or CONDITIONS ...)")
1552 (and . "(and CONDITIONS ...)")
1553 (if . "(if COND THEN ELSE...)")
1554 (cond . "(cond CLAUSES...)")
1555 (progn . "(progn BODY ...)")
1556 (prog1 . "(prog1 FIRST BODY...)")
1557 (prog2 . "(prog2 X Y BODY...)")
1558 (setq . "(setq SYM VAL SYM VAL ...)")
1559 (quote . "(quote ARG)")
1560 (function . "(function ARG)")
1561 (defun . "(defun NAME ARGLIST [DOCSTRING] BODY...)")
1562 (defmacro . "(defmacro NAME ARGLIST [DOCSTRING] BODY...)")
1563 (defvar . "(defvar SYMBOL [INITVALUE DOCSTRING])")
1564 (defconst . "(defconst SYMBOL INITVALUE [DOCSTRING])")
1565 (let* . "(let* VARLIST BODY...)")
1566 (let . "(let VARLIST BODY...)")
1567 (while . "(while TEST BODY...)")
1568 (catch . "(catch TAG BODY...)")
1569 (unwind-protect . "(unwind-protect BODYFORM UNWINDFORMS...)")
1570 (condition-case . "(condition-case VAR BODYFORM HANDLERS...)")
1571 (track-mouse . "(track-mouse BODY ...)")
1572 (ml-if . "(ml-if COND THEN ELSE...)")
1573 (ml-provide-prefix-argument . "(ml-provide-prefix-argument ARG1 ARG2)")
1574 (ml-prefix-argument-loop . "(ml-prefix-argument-loop ...)")
1575 (with-output-to-temp-buffer
1576 . "(with-output-to-temp-buffer BUFFNAME BODY ...)")
1577 (save-window-excursion . "(save-window-excursion BODY ...)")
1578 (find-operation-coding-system
1579 . "(find-operation-coding-system OPERATION ARGUMENTS ...)")
1580 (insert-before-markers-and-inherit
1581 . "(insert-before-markers-and-inherit &rest ARGS)"))))
1583 ;; Provide this for the sake of define-minor-mode which generates
1584 ;; defcustoms which require 'help'.
1588 ;;; help.el ends here