1 ;;; help-fns.el --- Complex help functions
3 ;; Copyright (C) 1985, 1986, 1993, 1994, 1998, 1999, 2000, 2001,
4 ;; 2002, 2003, 2004, 2005, 2006, 2007, 2008 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 3 of the License, or
14 ;; (at your option) any later version.
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. If not, see <http://www.gnu.org/licenses/>.
26 ;; This file contains those help commands which are complicated, and
27 ;; which may not be used in every session. For example
28 ;; `describe-function' will probably be heavily used when doing elisp
29 ;; programming, but not if just editing C files. Simpler help commands
39 (defun describe-function (function)
40 "Display the full documentation of FUNCTION (a symbol)."
42 (let ((fn (function-called-at-point))
43 (enable-recursive-minibuffers t)
45 (setq val (completing-read (if fn
46 (format "Describe function (default %s): " fn)
47 "Describe function: ")
48 obarray 'fboundp t nil nil
49 (and fn (symbol-name fn))))
50 (list (if (equal val "")
53 (message "You didn't specify a function")
54 (help-setup-xref (list #'describe-function function) (interactive-p))
56 (with-help-window (help-buffer)
58 ;; Use " is " instead of a colon so that
59 ;; it is easier to get out the function name using forward-sexp.
61 (describe-function-1 function)
62 (with-current-buffer standard-output
63 ;; Return the text we displayed.
66 (defun help-split-fundoc (docstring def)
67 "Split a function DOCSTRING into the actual doc and the usage info.
68 Return (USAGE . DOC) or nil if there's no usage info.
69 DEF is the function whose usage we're looking for in DOCSTRING."
70 ;; Functions can get the calling sequence at the end of the doc string.
71 ;; In cases where `function' has been fset to a subr we can't search for
72 ;; function's name in the doc string so we use `fn' as the anonymous
73 ;; function name instead.
74 (when (and docstring (string-match "\n\n(fn\\(\\( .*\\)?)\\)\\'" docstring))
76 ;; Replace `fn' with the actual function name.
77 (if (consp def) "anonymous" def)
78 (match-string 1 docstring))
79 (substring docstring 0 (match-beginning 0)))))
81 (defun help-add-fundoc-usage (docstring arglist)
82 "Add the usage info to DOCSTRING.
83 If DOCSTRING already has a usage info, then just return it unchanged.
84 The usage info is built from ARGLIST. DOCSTRING can be nil.
85 ARGLIST can also be t or a string of the form \"(FUN ARG1 ARG2 ...)\"."
86 (unless (stringp docstring) (setq docstring "Not documented"))
87 (if (or (string-match "\n\n(fn\\(\\( .*\\)?)\\)\\'" docstring) (eq arglist t))
90 (if (string-match "\n?\n\\'" docstring)
91 (if (< (- (match-end 0) (match-beginning 0)) 2) "\n" "")
93 (if (and (stringp arglist)
94 (string-match "\\`([^ ]+\\(.*\\))\\'" arglist))
95 (concat "(fn" (match-string 1 arglist) ")")
96 (format "%S" (help-make-usage 'fn arglist))))))
98 (defun help-function-arglist (def)
99 ;; Handle symbols aliased to other symbols.
100 (if (and (symbolp def) (fboundp def)) (setq def (indirect-function def)))
101 ;; If definition is a macro, find the function inside it.
102 (if (eq (car-safe def) 'macro) (setq def (cdr def)))
104 ((byte-code-function-p def) (aref def 0))
105 ((eq (car-safe def) 'lambda) (nth 1 def))
106 ((and (eq (car-safe def) 'autoload) (not (eq (nth 4 def) 'keymap)))
107 "[Arg list not available until function definition is loaded.]")
110 (defun help-make-usage (function arglist)
111 (cons (if (symbolp function) function 'anonymous)
112 (mapcar (lambda (arg)
113 (if (not (symbolp arg))
114 (if (and (consp arg) (symbolp (car arg)))
115 ;; CL style default values for optional args.
116 (cons (intern (upcase (symbol-name (car arg))))
119 (let ((name (symbol-name arg)))
120 (if (string-match "\\`&" name) arg
121 (intern (upcase name))))))
124 ;; Could be this, if we make symbol-file do the work below.
125 ;; (defun help-C-file-name (subr-or-var kind)
126 ;; "Return the name of the C file where SUBR-OR-VAR is defined.
127 ;; KIND should be `var' for a variable or `subr' for a subroutine."
128 ;; (symbol-file (if (symbolp subr-or-var) subr-or-var
129 ;; (subr-name subr-or-var))
130 ;; (if (eq kind 'var) 'defvar 'defun)))
132 (defun help-C-file-name (subr-or-var kind)
133 "Return the name of the C file where SUBR-OR-VAR is defined.
134 KIND should be `var' for a variable or `subr' for a subroutine."
135 (let ((docbuf (get-buffer-create " *DOC*"))
136 (name (if (eq 'var kind)
137 (concat "V" (symbol-name subr-or-var))
138 (concat "F" (subr-name subr-or-var)))))
139 (with-current-buffer docbuf
140 (goto-char (point-min))
142 (insert-file-contents-literally
143 (expand-file-name internal-doc-file-name doc-directory)))
144 (let ((file (catch 'loop
146 (let ((pnt (search-forward (concat "
\1f" name "\n"))))
147 (re-search-backward "
\1fS\\(.*\\)")
148 (let ((file (match-string 1)))
149 (if (member file build-files)
151 (goto-char pnt))))))))
152 (if (string-match "^ns.*\\(\\.o\\|obj\\)\\'" file)
153 (setq file (replace-match ".m" t t file 1))
154 (if (string-match "\\.\\(o\\|obj\\)\\'" file)
155 (setq file (replace-match ".c" t t file))))
156 (if (string-match "\\.\\(c\\|m\\)\\'" file)
160 (defface help-argument-name '((((supports :slant italic)) :inherit italic))
161 "Face to highlight argument names in *Help* buffers."
164 (defun help-default-arg-highlight (arg)
165 "Default function to highlight arguments in *Help* buffers.
166 It returns ARG in face `help-argument-name'; ARG is also
167 downcased if it displays differently than the default
168 face (according to `face-differs-from-default-p')."
169 (propertize (if (face-differs-from-default-p 'help-argument-name)
172 'face 'help-argument-name))
174 (defun help-do-arg-highlight (doc args)
175 (with-syntax-table (make-syntax-table emacs-lisp-mode-syntax-table)
176 (modify-syntax-entry ?\- "w")
177 (dolist (arg args doc)
178 (setq doc (replace-regexp-in-string
179 ;; This is heuristic, but covers all common cases
181 (concat "\\<" ; beginning of word
182 "\\(?:[a-z-]*-\\)?" ; for xxx-ARG
186 "\\(?:es\\|s\\|th\\)?" ; for ARGth, ARGs
187 "\\(?:-[a-z0-9-]+\\)?" ; for ARG-xxx, ARG-n
188 "\\(?:-[{([<`\"].*?\\)?"; for ARG-{x}, (x), <x>, [x], `x'
190 (help-default-arg-highlight arg)
193 (defun help-highlight-arguments (usage doc &rest args)
197 (goto-char (point-min))
198 (let ((case-fold-search nil)
199 (next (not (or args (looking-at "\\["))))
201 ;; Make a list of all arguments
202 (skip-chars-forward "^ ")
204 (or opt (not (looking-at " &")) (setq opt t))
205 (if (not (re-search-forward " \\([\\[(]*\\)\\([^] &)\.]+\\)" nil t))
207 (setq args (cons (match-string 2) args))
208 (when (and opt (string= (match-string 1) "("))
209 ;; A pesky CL-style optional argument with default value,
210 ;; so let's skip over it
211 (search-backward "(")
212 (goto-char (scan-sexps (point) 1)))))
213 ;; Highlight aguments in the USAGE string
214 (setq usage (help-do-arg-highlight (buffer-string) args))
215 ;; Highlight arguments in the DOC string
216 (setq doc (and doc (help-do-arg-highlight doc args))))))
217 ;; Return value is like the one from help-split-fundoc, but highlighted
221 (defun describe-simplify-lib-file-name (file)
222 "Simplify a library name FILE to a relative name, and make it a source file."
224 ;; Try converting the absolute file name to a library name.
225 (let ((libname (file-name-nondirectory file)))
226 ;; Now convert that back to a file name and see if we get
227 ;; the original one. If so, they are equivalent.
228 (if (equal file (locate-file libname load-path '("")))
229 (if (string-match "[.]elc\\'" libname)
230 (substring libname 0 -1)
234 (defun find-source-lisp-file (file-name)
235 (let* ((elc-file (locate-file (concat file-name
236 (if (string-match "\\.el" file-name)
240 (str (if (and elc-file (file-readable-p elc-file))
242 (insert-file-contents-literally elc-file nil 0 256)
245 (string-match ";;; from file \\(.*\\.el\\)" str)
246 (match-string 1 str))))
247 (if (and src-file (file-readable-p src-file))
251 (declare-function ad-get-advice-info "advice" (function))
254 (defun describe-function-1 (function)
255 (let* ((advised (and (symbolp function) (featurep 'advice)
256 (ad-get-advice-info function)))
257 ;; If the function is advised, use the symbol that has the
258 ;; real definition, if that symbol is already set up.
261 (cdr (assq 'origname advised))
262 (fboundp (cdr (assq 'origname advised)))
263 (cdr (assq 'origname advised)))
265 ;; Get the real definition.
266 (def (if (symbolp real-function)
267 (symbol-function real-function)
270 (beg (if (commandp def) "an interactive " "a "))
271 (pt1 (with-current-buffer (help-buffer) (point))))
273 (cond ((or (stringp def)
277 (if (eq 'unevalled (cdr (subr-arity def)))
278 (concat beg "special form")
279 (concat beg "built-in function")))
280 ((byte-code-function-p def)
281 (concat beg "compiled Lisp function"))
283 (while (symbolp (symbol-function def))
284 (setq def (symbol-function def)))
285 (format "an alias for `%s'" def))
286 ((eq (car-safe def) 'lambda)
287 (concat beg "Lisp function"))
288 ((eq (car-safe def) 'macro)
290 ((eq (car-safe def) 'autoload)
291 (setq file-name (nth 1 def))
292 (format "%s autoloaded %s"
293 (if (commandp def) "an interactive" "an")
294 (if (eq (nth 4 def) 'keymap) "keymap"
295 (if (nth 4 def) "Lisp macro" "Lisp function"))
299 (elts (cdr-safe def)))
301 (if (char-table-p (car-safe elts))
304 (setq elts (cdr-safe elts)))
310 (with-current-buffer standard-output
313 (if (re-search-backward "alias for `\\([^`']+\\)'" nil t)
314 (help-xref-button 1 'help-function def)))))
316 (setq file-name (symbol-file function 'defun)))
317 (setq file-name (describe-simplify-lib-file-name file-name))
318 (when (equal file-name "loaddefs.el")
319 ;; Find the real def site of the preloaded function.
320 ;; This is necessary only for defaliases.
323 (find-function-search-for-symbol function nil "loaddefs.el")
326 (with-current-buffer (car location)
327 (goto-char (cdr location))
328 (when (re-search-backward
329 "^;;; Generated autoloads from \\(.*\\)" nil t)
330 (setq file-name (match-string 1)))))))
331 (when (and (null file-name) (subrp def))
332 ;; Find the C source file name.
333 (setq file-name (if (get-buffer " *DOC*")
334 (help-C-file-name def 'subr)
338 ;; We used to add .el to the file name,
339 ;; but that's completely wrong when the user used load-file.
340 (princ (if (eq file-name 'C-source) "C source code" file-name))
342 ;; See if lisp files are present where they where installed from.
343 (if (not (eq file-name 'C-source))
344 (setq file-name (find-source-lisp-file file-name)))
346 ;; Make a hyperlink to the library.
347 (with-current-buffer standard-output
349 (re-search-backward "`\\([^`']+\\)'" nil t)
350 (help-xref-button 1 'help-function-def real-function file-name))))
352 (with-current-buffer (help-buffer)
353 (fill-region-as-paragraph (save-excursion (goto-char pt1) (forward-line 0) (point))
356 (when (commandp function)
357 (let ((pt2 (with-current-buffer (help-buffer) (point))))
358 (if (and (eq function 'self-insert-command)
359 (eq (key-binding "a") 'self-insert-command)
360 (eq (key-binding "b") 'self-insert-command)
361 (eq (key-binding "c") 'self-insert-command))
362 (princ "It is bound to many ordinary text characters.\n")
363 (let* ((remapped (command-remapping function))
364 (keys (where-is-internal
365 (or remapped function) overriding-local-map nil nil))
367 ;; Which non-control non-meta keys run this command?
369 (if (member (event-modifiers (aref key 0)) '(nil (shift)))
370 (push key non-modified-keys)))
372 (princ "It is remapped to `")
373 (princ (symbol-name remapped))
377 (princ (if remapped ", which is bound to " "It is bound to "))
378 ;; If lots of ordinary text characters run this command,
379 ;; don't mention them one by one.
380 (if (< (length non-modified-keys) 10)
381 (princ (mapconcat 'key-description keys ", "))
382 (dolist (key non-modified-keys)
383 (setq keys (delq key keys)))
386 (princ (mapconcat 'key-description keys ", "))
387 (princ ", and many ordinary text characters"))
388 (princ "many ordinary text characters"))))
389 (when (or remapped keys non-modified-keys)
392 (with-current-buffer (help-buffer) (fill-region-as-paragraph pt2 (point)))
394 (let* ((arglist (help-function-arglist def))
395 (doc (documentation function))
396 (usage (help-split-fundoc doc function)))
397 (with-current-buffer standard-output
398 ;; If definition is a keymap, skip arglist note.
399 (unless (keymapp function)
401 (usage (setq doc (cdr usage)) (car usage))
403 (format "%S" (help-make-usage function arglist)))
404 ((stringp arglist) arglist)
405 ;; Maybe the arglist is in the docstring of a symbol
406 ;; this one is aliased to.
407 ((let ((fun real-function))
408 (while (and (symbolp fun)
409 (setq fun (symbol-function fun))
410 (not (setq usage (help-split-fundoc
417 (format "\nMacro: %s" (format-kbd-macro def)))
418 (t "[Missing arglist. Please make a bug report.]")))
419 (high (help-highlight-arguments use doc)))
420 (let ((fill-begin (point)))
421 (insert (car high) "\n")
422 (fill-region fill-begin (point)))
423 (setq doc (cdr high))))
424 (let* ((obsolete (and
425 ;; function might be a lambda construct.
427 (get function 'byte-obsolete-info)))
428 (use (car obsolete)))
430 (princ "\nThis function is obsolete")
431 (when (nth 2 obsolete)
432 (insert (format " since %s" (nth 2 obsolete))))
433 (insert (cond ((stringp use) (concat ";\n" use))
434 (use (format ";\nuse `%s' instead." use))
438 (or doc "Not documented.")))))))
444 (defun variable-at-point (&optional any-symbol)
445 "Return the bound variable symbol found at or before point.
446 Return 0 if there is no such symbol.
447 If ANY-SYMBOL is non-nil, don't insist the symbol be bound."
448 (with-syntax-table emacs-lisp-mode-syntax-table
449 (or (condition-case ()
451 (or (not (zerop (skip-syntax-backward "_w")))
452 (eq (char-syntax (following-char)) ?w)
453 (eq (char-syntax (following-char)) ?_)
455 (skip-chars-forward "'")
456 (let ((obj (read (current-buffer))))
457 (and (symbolp obj) (boundp obj) obj)))
459 (let* ((str (find-tag-default))
460 (sym (if str (intern-soft str))))
461 (if (and sym (or any-symbol (boundp sym)))
464 (when (and str (string-match "\\`\\W*\\(.*?\\)\\W*\\'" str))
465 (setq sym (intern-soft (match-string 1 str)))
466 (and (or any-symbol (boundp sym)) sym)))))
469 (defun describe-variable-custom-version-info (variable)
470 (let ((custom-version (get variable 'custom-version))
471 (cpv (get variable 'custom-package-version))
475 (format "This variable was introduced, or its default value was changed, in\nversion %s of Emacs.\n"
478 (let* ((package (car-safe cpv))
479 (version (if (listp (cdr-safe cpv))
482 (pkg-versions (assq package customize-package-emacs-version-alist))
483 (emacsv (cdr (assoc version pkg-versions))))
484 (if (and package version)
486 (format (concat "This variable was introduced, or its default value was changed, in\nversion %s of the %s package"
488 (format " that is part of Emacs %s" emacsv))
490 version package))))))
494 (defun describe-variable (variable &optional buffer frame)
495 "Display the full documentation of VARIABLE (a symbol).
496 Returns the documentation as a string, also.
497 If VARIABLE has a buffer-local value in BUFFER or FRAME
498 \(default to the current buffer and current frame),
499 it is displayed along with the global value."
501 (let ((v (variable-at-point))
502 (enable-recursive-minibuffers t)
504 (setq val (completing-read (if (symbolp v)
506 "Describe variable (default %s): " v)
507 "Describe variable: ")
511 (get vv 'variable-documentation)))
513 (if (symbolp v) (symbol-name v))))
514 (list (if (equal val "")
516 (unless (buffer-live-p buffer) (setq buffer (current-buffer)))
517 (unless (frame-live-p frame) (setq frame (selected-frame)))
518 (if (not (symbolp variable))
519 (message "You did not specify a variable")
521 (let ((valvoid (not (with-current-buffer buffer (boundp variable))))
522 val val-start-pos locus)
523 ;; Extract the value before setting up the output buffer,
524 ;; in case `buffer' *is* the output buffer.
526 (with-selected-frame frame
527 (with-current-buffer buffer
528 (setq val (symbol-value variable)
529 locus (variable-binding-locus variable)))))
530 (help-setup-xref (list #'describe-variable variable buffer)
532 (with-help-window (help-buffer)
533 (with-current-buffer buffer
535 ;; Make a hyperlink to the library if appropriate. (Don't
536 ;; change the format of the buffer's initial line in case
537 ;; anything expects the current format.)
538 (let ((file-name (symbol-file variable 'defvar)))
539 (setq file-name (describe-simplify-lib-file-name file-name))
540 (when (equal file-name "loaddefs.el")
541 ;; Find the real def site of the preloaded variable.
544 (find-variable-noselect variable file-name)
547 (with-current-buffer (car location)
549 (goto-char (cdr location)))
550 (when (re-search-backward
551 "^;;; Generated autoloads from \\(.*\\)" nil t)
552 (setq file-name (match-string 1)))))))
553 (when (and (null file-name)
554 (integerp (get variable 'variable-documentation)))
555 ;; It's a variable not defined in Elisp but in C.
557 (if (get-buffer " *DOC*")
558 (help-C-file-name variable 'var)
562 (princ " is a variable defined in `")
563 (princ (if (eq file-name 'C-source) "C source code" file-name))
565 (with-current-buffer standard-output
567 (re-search-backward "`\\([^`']+\\)'" nil t)
568 (help-xref-button 1 'help-variable-def
569 variable file-name)))
571 (princ "It is void as a variable.")
574 (princ " is void as a variable.")
578 (with-current-buffer standard-output
579 (setq val-start-pos (point))
582 (let ((from (point)))
584 ;; Hyperlinks in variable's value are quite frequently
585 ;; inappropriate e.g C-h v <RET> features <RET>
586 ;; (help-xref-on-pp from (point))
587 (if (< (point) (+ from 20))
588 (delete-region (1- from) from)))))
593 (princ (format "%socal in buffer %s; "
594 (if (get variable 'permanent-local)
597 (princ (format "It is a frame-local variable; ")))
598 (if (not (default-boundp variable))
599 (princ "globally void")
600 (let ((val (default-value variable)))
601 (with-current-buffer standard-output
602 (princ "global value is ")
604 ;; Fixme: pp can take an age if you happen to
605 ;; ask for a very large expression. We should
606 ;; probably print it raw once and check it's a
607 ;; sensible size before prettyprinting. -- fx
608 (let ((from (point)))
610 ;; See previous comment for this function.
611 ;; (help-xref-on-pp from (point))
612 (if (< (point) (+ from 20))
613 (delete-region (1- from) from))))))
616 ;; If the value is large, move it to the end.
617 (with-current-buffer standard-output
618 (when (> (count-lines (point-min) (point-max)) 10)
619 ;; Note that setting the syntax table like below
620 ;; makes forward-sexp move over a `'s' at the end
622 (set-syntax-table emacs-lisp-mode-syntax-table)
623 (goto-char val-start-pos)
624 ;; The line below previously read as
625 ;; (delete-region (point) (progn (end-of-line) (point)))
626 ;; which suppressed display of the buffer local value for
628 (when (looking-at "value is") (replace-match ""))
630 (insert "\n\nValue:")
631 (set (make-local-variable 'help-button-cache)
633 (insert "value is shown ")
634 (insert-button "below"
635 'action help-button-cache
637 'help-echo "mouse-2, RET: show value")
641 (let* ((alias (condition-case nil
642 (indirect-variable variable)
644 (obsolete (get variable 'byte-obsolete-variable))
646 (safe-var (get variable 'safe-local-variable))
647 (doc (or (documentation-property variable 'variable-documentation)
648 (documentation-property alias 'variable-documentation)))
650 ;; Add a note for variables that have been make-var-buffer-local.
651 (when (and (local-variable-if-set-p variable)
652 (or (not (local-variable-p variable))
654 (local-variable-if-set-p variable))))
656 (princ " Automatically becomes buffer-local when set in any fashion.\n"))
658 ;; Mention if it's an alias
659 (unless (eq alias variable)
661 (princ (format " This variable is an alias for `%s'.\n" alias)))
665 (princ " This variable is obsolete")
666 (if (cdr obsolete) (princ (format " since %s" (cdr obsolete))))
667 (princ (cond ((stringp use) (concat ";\n " use))
668 (use (format ";\n use `%s' instead." (car obsolete)))
673 (princ " This variable is safe as a file local variable ")
674 (princ "if its value\n satisfies the predicate ")
675 (princ (if (byte-code-function-p safe-var)
676 "which is byte-compiled expression.\n"
677 (format "`%s'.\n" safe-var))))
679 (if extra-line (terpri))
680 (princ "Documentation:\n")
681 (with-current-buffer standard-output
682 (insert (or doc "Not documented as a variable."))))
684 ;; Make a link to customize if this variable can be customized.
685 (when (custom-variable-p variable)
686 (let ((customize-label "customize"))
689 (princ (concat "You can " customize-label " this variable."))
690 (with-current-buffer standard-output
693 (concat "\\(" customize-label "\\)") nil t)
694 (help-xref-button 1 'help-customize-variable variable))))
695 ;; Note variable's version or package version
696 (let ((output (describe-variable-custom-version-info variable)))
703 (set-buffer standard-output)
704 ;; Return the text we displayed.
705 (buffer-string))))))))
709 (defun describe-syntax (&optional buffer)
710 "Describe the syntax specifications in the syntax table of BUFFER.
711 The descriptions are inserted in a help buffer, which is then displayed.
712 BUFFER defaults to the current buffer."
714 (setq buffer (or buffer (current-buffer)))
715 (help-setup-xref (list #'describe-syntax buffer) (interactive-p))
716 (with-help-window (help-buffer)
717 (let ((table (with-current-buffer buffer (syntax-table))))
718 (with-current-buffer standard-output
719 (describe-vector table 'internal-describe-syntax-value)
720 (while (setq table (char-table-parent table))
721 (insert "\nThe parent syntax table is:")
722 (describe-vector table 'internal-describe-syntax-value))))))
724 (defun help-describe-category-set (value)
726 ((null value) "default")
727 ((char-table-p value) "deeper char-table ...")
728 (t (condition-case err
729 (category-set-mnemonics value)
730 (error "invalid"))))))
733 (defun describe-categories (&optional buffer)
734 "Describe the category specifications in the current category table.
735 The descriptions are inserted in a buffer, which is then displayed.
736 If BUFFER is non-nil, then describe BUFFER's category table instead.
737 BUFFER should be a buffer or a buffer name."
739 (setq buffer (or buffer (current-buffer)))
740 (help-setup-xref (list #'describe-categories buffer) (interactive-p))
741 (with-help-window (help-buffer)
742 (let ((table (with-current-buffer buffer (category-table))))
743 (with-current-buffer standard-output
744 (describe-vector table 'help-describe-category-set)
745 (let ((docs (char-table-extra-slot table 0)))
746 (if (or (not (vectorp docs)) (/= (length docs) 95))
747 (insert "Invalid first extra slot in this char table\n")
748 (insert "Meanings of mnemonic characters are:\n")
750 (let ((elt (aref docs i)))
752 (insert (+ i ?\s) ": " elt "\n"))))
753 (while (setq table (char-table-parent table))
754 (insert "\nThe parent category table is:")
755 (describe-vector table 'help-describe-category-set))))))))
759 ;; arch-tag: 9e10331c-ae81-4d13-965d-c4819aaab0b3
760 ;;; help-fns.el ends here