1 ;;; help-fns.el --- Complex help functions
3 ;; Copyright (C) 1985, 1986, 1993, 1994, 1998, 1999, 2000, 2001, 2002,
4 ;; 2003, 2004, 2005, 2006, 2007, 2008, 2009
5 ;; Free Software Foundation, Inc.
8 ;; Keywords: help, internal
10 ;; This file is part of GNU Emacs.
12 ;; GNU Emacs is free software: you can redistribute it and/or modify
13 ;; it under the terms of the GNU General Public License as published by
14 ;; the Free Software Foundation, either version 3 of the License, or
15 ;; (at your option) any later version.
17 ;; GNU Emacs is distributed in the hope that it will be useful,
18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 ;; GNU General Public License for more details.
22 ;; You should have received a copy of the GNU General Public License
23 ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
27 ;; This file contains those help commands which are complicated, and
28 ;; which may not be used in every session. For example
29 ;; `describe-function' will probably be heavily used when doing elisp
30 ;; programming, but not if just editing C files. Simpler help commands
40 (defun describe-function (function)
41 "Display the full documentation of FUNCTION (a symbol)."
43 (let ((fn (function-called-at-point))
44 (enable-recursive-minibuffers t)
46 (setq val (completing-read (if fn
47 (format "Describe function (default %s): " fn)
48 "Describe function: ")
49 obarray 'fboundp t nil nil
50 (and fn (symbol-name fn))))
51 (list (if (equal val "")
54 (message "You didn't specify a function")
55 (help-setup-xref (list #'describe-function function)
56 (called-interactively-p 'interactive))
58 (with-help-window (help-buffer)
60 ;; Use " is " instead of a colon so that
61 ;; it is easier to get out the function name using forward-sexp.
63 (describe-function-1 function)
64 (with-current-buffer standard-output
65 ;; Return the text we displayed.
68 (defun help-split-fundoc (docstring def)
69 "Split a function DOCSTRING into the actual doc and the usage info.
70 Return (USAGE . DOC) or nil if there's no usage info.
71 DEF is the function whose usage we're looking for in DOCSTRING."
72 ;; Functions can get the calling sequence at the end of the doc string.
73 ;; In cases where `function' has been fset to a subr we can't search for
74 ;; function's name in the doc string so we use `fn' as the anonymous
75 ;; function name instead.
76 (when (and docstring (string-match "\n\n(fn\\(\\( .*\\)?)\\)\\'" docstring))
78 ;; Replace `fn' with the actual function name.
79 (if (consp def) "anonymous" def)
80 (match-string 1 docstring))
81 (substring docstring 0 (match-beginning 0)))))
83 (defun help-add-fundoc-usage (docstring arglist)
84 "Add the usage info to DOCSTRING.
85 If DOCSTRING already has a usage info, then just return it unchanged.
86 The usage info is built from ARGLIST. DOCSTRING can be nil.
87 ARGLIST can also be t or a string of the form \"(FUN ARG1 ARG2 ...)\"."
88 (unless (stringp docstring) (setq docstring "Not documented"))
89 (if (or (string-match "\n\n(fn\\(\\( .*\\)?)\\)\\'" docstring) (eq arglist t))
92 (if (string-match "\n?\n\\'" docstring)
93 (if (< (- (match-end 0) (match-beginning 0)) 2) "\n" "")
95 (if (and (stringp arglist)
96 (string-match "\\`([^ ]+\\(.*\\))\\'" arglist))
97 (concat "(fn" (match-string 1 arglist) ")")
98 (format "%S" (help-make-usage 'fn arglist))))))
100 (defun help-function-arglist (def)
101 ;; Handle symbols aliased to other symbols.
102 (if (and (symbolp def) (fboundp def)) (setq def (indirect-function def)))
103 ;; If definition is a macro, find the function inside it.
104 (if (eq (car-safe def) 'macro) (setq def (cdr def)))
106 ((byte-code-function-p def) (aref def 0))
107 ((eq (car-safe def) 'lambda) (nth 1 def))
108 ((and (eq (car-safe def) 'autoload) (not (eq (nth 4 def) 'keymap)))
109 "[Arg list not available until function definition is loaded.]")
112 (defun help-make-usage (function arglist)
113 (cons (if (symbolp function) function 'anonymous)
114 (mapcar (lambda (arg)
115 (if (not (symbolp arg))
116 (if (and (consp arg) (symbolp (car arg)))
117 ;; CL style default values for optional args.
118 (cons (intern (upcase (symbol-name (car arg))))
121 (let ((name (symbol-name arg)))
122 (if (string-match "\\`&" name) arg
123 (intern (upcase name))))))
126 ;; Could be this, if we make symbol-file do the work below.
127 ;; (defun help-C-file-name (subr-or-var kind)
128 ;; "Return the name of the C file where SUBR-OR-VAR is defined.
129 ;; KIND should be `var' for a variable or `subr' for a subroutine."
130 ;; (symbol-file (if (symbolp subr-or-var) subr-or-var
131 ;; (subr-name subr-or-var))
132 ;; (if (eq kind 'var) 'defvar 'defun)))
134 (defun help-C-file-name (subr-or-var kind)
135 "Return the name of the C file where SUBR-OR-VAR is defined.
136 KIND should be `var' for a variable or `subr' for a subroutine."
137 (let ((docbuf (get-buffer-create " *DOC*"))
138 (name (if (eq 'var kind)
139 (concat "V" (symbol-name subr-or-var))
140 (concat "F" (subr-name subr-or-var)))))
141 (with-current-buffer docbuf
142 (goto-char (point-min))
144 (insert-file-contents-literally
145 (expand-file-name internal-doc-file-name doc-directory)))
146 (let ((file (catch 'loop
148 (let ((pnt (search-forward (concat "
\1f" name "\n"))))
149 (re-search-backward "
\1fS\\(.*\\)")
150 (let ((file (match-string 1)))
151 (if (member file build-files)
153 (goto-char pnt))))))))
154 (if (string-match "^ns.*\\(\\.o\\|obj\\)\\'" file)
155 (setq file (replace-match ".m" t t file 1))
156 (if (string-match "\\.\\(o\\|obj\\)\\'" file)
157 (setq file (replace-match ".c" t t file))))
158 (if (string-match "\\.\\(c\\|m\\)\\'" file)
162 (defcustom help-downcase-arguments nil
163 "If non-nil, argument names in *Help* buffers are downcased."
168 (defun help-highlight-arg (arg)
169 "Highlight ARG as an argument name for a *Help* buffer.
170 Return ARG in face `help-argument-name'; ARG is also downcased
171 if the variable `help-downcase-arguments' is non-nil."
172 (propertize (if help-downcase-arguments (downcase arg) arg)
173 'face 'help-argument-name))
175 (defun help-do-arg-highlight (doc args)
176 (with-syntax-table (make-syntax-table emacs-lisp-mode-syntax-table)
177 (modify-syntax-entry ?\- "w")
178 (dolist (arg args doc)
179 (setq doc (replace-regexp-in-string
180 ;; This is heuristic, but covers all common cases
182 (concat "\\<" ; beginning of word
183 "\\(?:[a-z-]*-\\)?" ; for xxx-ARG
187 "\\(?:es\\|s\\|th\\)?" ; for ARGth, ARGs
188 "\\(?:-[a-z0-9-]+\\)?" ; for ARG-xxx, ARG-n
189 "\\(?:-[{([<`\"].*?\\)?"; for ARG-{x}, (x), <x>, [x], `x'
191 (help-highlight-arg arg)
194 (defun help-highlight-arguments (usage doc &rest args)
198 (goto-char (point-min))
199 (let ((case-fold-search nil)
200 (next (not (or args (looking-at "\\["))))
202 ;; Make a list of all arguments
203 (skip-chars-forward "^ ")
205 (or opt (not (looking-at " &")) (setq opt t))
206 (if (not (re-search-forward " \\([\\[(]*\\)\\([^] &)\.]+\\)" nil t))
208 (setq args (cons (match-string 2) args))
209 (when (and opt (string= (match-string 1) "("))
210 ;; A pesky CL-style optional argument with default value,
211 ;; so let's skip over it
212 (search-backward "(")
213 (goto-char (scan-sexps (point) 1)))))
214 ;; Highlight aguments in the USAGE string
215 (setq usage (help-do-arg-highlight (buffer-string) args))
216 ;; Highlight arguments in the DOC string
217 (setq doc (and doc (help-do-arg-highlight doc args))))))
218 ;; Return value is like the one from help-split-fundoc, but highlighted
221 ;; The following function was compiled from the former functions
222 ;; `describe-simplify-lib-file-name' and `find-source-lisp-file' with
223 ;; some excerpts from `describe-function-1' and `describe-variable'.
224 ;; The only additional twists provided are (1) locate the defining file
225 ;; for autoloaded functions, and (2) give preference to files in the
226 ;; "install directory" (directories found via `load-path') rather than
227 ;; to files in the "compile directory" (directories found by searching
228 ;; the loaddefs.el file). We autoload it because it's also used by
229 ;; `describe-face' (instead of `describe-simplify-lib-file-name').
232 (defun find-lisp-object-file-name (object type)
233 "Guess the file that defined the Lisp object OBJECT, of type TYPE.
234 OBJECT should be a symbol associated with a function, variable, or face;
235 alternatively, it can be a function definition.
236 If TYPE is `variable', search for a variable definition.
237 If TYPE is `face', search for a face definition.
238 If TYPE is the value returned by `symbol-function' for a function symbol,
239 search for a function definition.
241 The return value is the absolute name of a readable file where OBJECT is
242 defined. If several such files exist, preference is given to a file
243 found via `load-path'. The return value can also be `C-source', which
244 means that OBJECT is a function or variable defined in C. If no
245 suitable file is found, return nil."
246 (let* ((autoloaded (eq (car-safe type) 'autoload))
247 (file-name (or (and autoloaded (nth 1 type))
249 object (if (memq type (list 'defvar 'defface))
254 ;; An autoloaded function: Locate the file since `symbol-function'
255 ;; has only returned a bare string here.
257 (locate-file file-name load-path '(".el" ".elc") 'readable)))
258 ((and (stringp file-name)
259 (string-match "[.]*loaddefs.el\\'" file-name))
260 ;; An autoloaded variable or face. Visit loaddefs.el in a buffer
261 ;; and try to extract the defining file. The following form is
262 ;; from `describe-function-1' and `describe-variable'.
265 (find-function-search-for-symbol object nil file-name)
268 (with-current-buffer (car location)
269 (goto-char (cdr location))
270 (when (re-search-backward
271 "^;;; Generated autoloads from \\(.*\\)" nil t)
274 (file-name-sans-extension
275 (match-string-no-properties 1))
276 load-path '(".el" ".elc") 'readable))))))))
279 ((and (not file-name) (subrp type))
280 ;; A built-in function. The form is from `describe-function-1'.
281 (if (get-buffer " *DOC*")
282 (help-C-file-name type 'subr)
284 ((and (not file-name) (symbolp object)
285 (integerp (get object 'variable-documentation)))
286 ;; A variable defined in C. The form is from `describe-variable'.
287 (if (get-buffer " *DOC*")
288 (help-C-file-name object 'var)
290 ((not (stringp file-name))
291 ;; If we don't have a file-name string by now, we lost.
294 (if (string-match "[.]elc\\'" file-name)
295 (substring-no-properties file-name 0 -1)
297 ;; When the Elisp source file can be found in the install
298 ;; directory return the name of that file - `file-name' should
299 ;; have become an absolute file name ny now.
300 (or (and (file-readable-p lib-name) lib-name)
301 ;; The library might be compressed.
302 (and (file-readable-p (concat lib-name ".gz")) lib-name))))
303 ((let* ((lib-name (file-name-nondirectory file-name))
304 ;; The next form is from `describe-simplify-lib-file-name'.
306 ;; Try converting the absolute file name to a library
307 ;; name, convert that back to a file name and see if we
308 ;; get the original one. If so, they are equivalent.
309 (if (equal file-name (locate-file lib-name load-path '("")))
310 (if (string-match "[.]elc\\'" lib-name)
311 (substring-no-properties lib-name 0 -1)
314 ;; The next three forms are from `find-source-lisp-file'.
315 (elc-file (locate-file
317 (if (string-match "\\.el\\'" file-name)
320 load-path nil 'readable))
323 (insert-file-contents-literally elc-file nil 0 256)
326 (string-match ";;; from file \\(.*\\.el\\)" str)
327 (match-string 1 str))))
328 (and src-file (file-readable-p src-file) src-file))))))
330 (declare-function ad-get-advice-info "advice" (function))
333 (defun describe-function-1 (function)
334 (let* ((advised (and (symbolp function) (featurep 'advice)
335 (ad-get-advice-info function)))
336 ;; If the function is advised, use the symbol that has the
337 ;; real definition, if that symbol is already set up.
340 (let ((origname (cdr (assq 'origname advised))))
341 (and (fboundp origname) origname)))
343 ;; Get the real definition.
344 (def (if (symbolp real-function)
345 (symbol-function real-function)
348 (beg (if (commandp def) "an interactive " "a "))
349 (pt1 (with-current-buffer (help-buffer) (point)))
352 (cond ((or (stringp def)
356 (if (eq 'unevalled (cdr (subr-arity def)))
357 (concat beg "special form")
358 (concat beg "built-in function")))
359 ((byte-code-function-p def)
360 (concat beg "compiled Lisp function"))
362 (while (and (fboundp def)
363 (symbolp (symbol-function def)))
364 (setq def (symbol-function def)))
365 ;; Handle (defalias 'foo 'bar), where bar is undefined.
366 (or (fboundp def) (setq errtype 'alias))
367 (format "an alias for `%s'" def))
368 ((eq (car-safe def) 'lambda)
369 (concat beg "Lisp function"))
370 ((eq (car-safe def) 'macro)
372 ((eq (car-safe def) 'autoload)
373 (format "%s autoloaded %s"
374 (if (commandp def) "an interactive" "an")
375 (if (eq (nth 4 def) 'keymap) "keymap"
376 (if (nth 4 def) "Lisp macro" "Lisp function"))))
379 (elts (cdr-safe def)))
381 (if (char-table-p (car-safe elts))
384 (setq elts (cdr-safe elts)))
390 (if (eq errtype 'alias)
391 (princ ",\nwhich is not defined. Please make a bug report.")
392 (with-current-buffer standard-output
395 (when (re-search-backward "alias for `\\([^`']+\\)'" nil t)
396 (help-xref-button 1 'help-function def)))))
398 (setq file-name (find-lisp-object-file-name function def))
401 ;; We used to add .el to the file name,
402 ;; but that's completely wrong when the user used load-file.
403 (princ (if (eq file-name 'C-source)
405 (file-name-nondirectory file-name)))
407 ;; Make a hyperlink to the library.
408 (with-current-buffer standard-output
410 (re-search-backward "`\\([^`']+\\)'" nil t)
411 (help-xref-button 1 'help-function-def function file-name))))
413 (with-current-buffer (help-buffer)
414 (fill-region-as-paragraph (save-excursion (goto-char pt1) (forward-line 0) (point))
417 (when (commandp function)
418 (let ((pt2 (with-current-buffer (help-buffer) (point)))
419 (remapped (command-remapping function)))
420 (unless (memq remapped '(ignore undefined))
421 (let ((keys (where-is-internal
422 (or remapped function) overriding-local-map nil nil))
424 (if (and (eq function 'self-insert-command)
425 (vectorp (car-safe keys))
426 (consp (aref (car keys) 0)))
427 (princ "It is bound to many ordinary text characters.\n")
428 ;; Which non-control non-meta keys run this command?
430 (if (member (event-modifiers (aref key 0)) '(nil (shift)))
431 (push key non-modified-keys)))
433 (princ "It is remapped to `")
434 (princ (symbol-name remapped))
438 (princ (if remapped ", which is bound to " "It is bound to "))
439 ;; If lots of ordinary text characters run this command,
440 ;; don't mention them one by one.
441 (if (< (length non-modified-keys) 10)
442 (princ (mapconcat 'key-description keys ", "))
443 (dolist (key non-modified-keys)
444 (setq keys (delq key keys)))
447 (princ (mapconcat 'key-description keys ", "))
448 (princ ", and many ordinary text characters"))
449 (princ "many ordinary text characters"))))
450 (when (or remapped keys non-modified-keys)
454 (with-current-buffer (help-buffer)
455 (fill-region-as-paragraph pt2 (point))
456 (unless (looking-back "\n\n")
458 ;; Note that list* etc do not get this property until
459 ;; cl-hack-byte-compiler runs, after bytecomp is loaded.
460 (when (eq (get function 'byte-compile) 'cl-byte-compile-compiler-macro)
461 (princ "This function has a compiler macro")
462 (let ((lib (get function 'compiler-macro-file)))
464 (princ (format " in `%s'" lib))
465 (with-current-buffer standard-output
467 (re-search-backward "`\\([^`']+\\)'" nil t)
468 (help-xref-button 1 'help-function-cmacro function lib)))))
470 (let* ((advertised (gethash def advertised-signature-table t))
471 (arglist (if (listp advertised)
472 advertised (help-function-arglist def)))
473 (doc (documentation function))
474 (usage (help-split-fundoc doc function)))
475 (with-current-buffer standard-output
476 ;; If definition is a keymap, skip arglist note.
477 (unless (keymapp function)
478 (if usage (setq doc (cdr usage)))
480 ((and usage (not (listp advertised))) (car usage))
482 (format "%S" (help-make-usage function arglist)))
483 ((stringp arglist) arglist)
484 ;; Maybe the arglist is in the docstring of a symbol
485 ;; this one is aliased to.
486 ((let ((fun real-function))
487 (while (and (symbolp fun)
488 (setq fun (symbol-function fun))
489 (not (setq usage (help-split-fundoc
496 (format "\nMacro: %s" (format-kbd-macro def)))
497 (t "[Missing arglist. Please make a bug report.]")))
498 (high (help-highlight-arguments use doc)))
499 (let ((fill-begin (point)))
500 (insert (car high) "\n")
501 (fill-region fill-begin (point)))
502 (setq doc (cdr high))))
503 (let* ((obsolete (and
504 ;; function might be a lambda construct.
506 (get function 'byte-obsolete-info)))
507 (use (car obsolete)))
509 (princ "\nThis function is obsolete")
510 (when (nth 2 obsolete)
511 (insert (format " since %s" (nth 2 obsolete))))
512 (insert (cond ((stringp use) (concat ";\n" use))
513 (use (format ";\nuse `%s' instead." use))
517 (or doc "Not documented."))))))))
523 (defun variable-at-point (&optional any-symbol)
524 "Return the bound variable symbol found at or before point.
525 Return 0 if there is no such symbol.
526 If ANY-SYMBOL is non-nil, don't insist the symbol be bound."
527 (with-syntax-table emacs-lisp-mode-syntax-table
528 (or (condition-case ()
530 (or (not (zerop (skip-syntax-backward "_w")))
531 (eq (char-syntax (following-char)) ?w)
532 (eq (char-syntax (following-char)) ?_)
534 (skip-chars-forward "'")
535 (let ((obj (read (current-buffer))))
536 (and (symbolp obj) (boundp obj) obj)))
538 (let* ((str (find-tag-default))
539 (sym (if str (intern-soft str))))
540 (if (and sym (or any-symbol (boundp sym)))
543 (when (and str (string-match "\\`\\W*\\(.*?\\)\\W*\\'" str))
544 (setq sym (intern-soft (match-string 1 str)))
545 (and (or any-symbol (boundp sym)) sym)))))
548 (defun describe-variable-custom-version-info (variable)
549 (let ((custom-version (get variable 'custom-version))
550 (cpv (get variable 'custom-package-version))
554 (format "This variable was introduced, or its default value was changed, in\nversion %s of Emacs.\n"
557 (let* ((package (car-safe cpv))
558 (version (if (listp (cdr-safe cpv))
561 (pkg-versions (assq package customize-package-emacs-version-alist))
562 (emacsv (cdr (assoc version pkg-versions))))
563 (if (and package version)
565 (format (concat "This variable was introduced, or its default value was changed, in\nversion %s of the %s package"
567 (format " that is part of Emacs %s" emacsv))
569 version package))))))
573 (defun describe-variable (variable &optional buffer frame)
574 "Display the full documentation of VARIABLE (a symbol).
575 Returns the documentation as a string, also.
576 If VARIABLE has a buffer-local value in BUFFER or FRAME
577 \(default to the current buffer and current frame),
578 it is displayed along with the global value."
580 (let ((v (variable-at-point))
581 (enable-recursive-minibuffers t)
583 (setq val (completing-read (if (symbolp v)
585 "Describe variable (default %s): " v)
586 "Describe variable: ")
590 (get vv 'variable-documentation)))
592 (if (symbolp v) (symbol-name v))))
593 (list (if (equal val "")
596 (unless (buffer-live-p buffer) (setq buffer (current-buffer)))
597 (unless (frame-live-p frame) (setq frame (selected-frame)))
598 (if (not (symbolp variable))
599 (message "You did not specify a variable")
601 (let ((valvoid (not (with-current-buffer buffer (boundp variable))))
602 val val-start-pos locus)
603 ;; Extract the value before setting up the output buffer,
604 ;; in case `buffer' *is* the output buffer.
606 (with-selected-frame frame
607 (with-current-buffer buffer
608 (setq val (symbol-value variable)
609 locus (variable-binding-locus variable)))))
610 (help-setup-xref (list #'describe-variable variable buffer)
611 (called-interactively-p 'interactive))
612 (with-help-window (help-buffer)
613 (with-current-buffer buffer
615 (setq file-name (find-lisp-object-file-name variable 'defvar))
619 (princ " is a variable defined in `")
620 (princ (if (eq file-name 'C-source)
622 (file-name-nondirectory file-name)))
624 (with-current-buffer standard-output
626 (re-search-backward "`\\([^`']+\\)'" nil t)
627 (help-xref-button 1 'help-variable-def
628 variable file-name)))
630 (princ "It is void as a variable.")
633 (princ " is void as a variable.")
637 (with-current-buffer standard-output
638 (setq val-start-pos (point))
641 (let ((from (point)))
643 ;; Hyperlinks in variable's value are quite frequently
644 ;; inappropriate e.g C-h v <RET> features <RET>
645 ;; (help-xref-on-pp from (point))
646 (if (< (point) (+ from 20))
647 (delete-region (1- from) from)))))
652 (princ (format "%socal in buffer %s; "
653 (if (get variable 'permanent-local)
656 (princ (format "It is a frame-local variable; ")))
657 (if (not (default-boundp variable))
658 (princ "globally void")
659 (let ((val (default-value variable)))
660 (with-current-buffer standard-output
661 (princ "global value is ")
663 ;; Fixme: pp can take an age if you happen to
664 ;; ask for a very large expression. We should
665 ;; probably print it raw once and check it's a
666 ;; sensible size before prettyprinting. -- fx
667 (let ((from (point)))
669 ;; See previous comment for this function.
670 ;; (help-xref-on-pp from (point))
671 (if (< (point) (+ from 20))
672 (delete-region (1- from) from))))))
675 ;; If the value is large, move it to the end.
676 (with-current-buffer standard-output
677 (when (> (count-lines (point-min) (point-max)) 10)
678 ;; Note that setting the syntax table like below
679 ;; makes forward-sexp move over a `'s' at the end
681 (set-syntax-table emacs-lisp-mode-syntax-table)
682 (goto-char val-start-pos)
683 ;; The line below previously read as
684 ;; (delete-region (point) (progn (end-of-line) (point)))
685 ;; which suppressed display of the buffer local value for
687 (when (looking-at "value is") (replace-match ""))
689 (insert "\n\nValue:")
690 (set (make-local-variable 'help-button-cache)
692 (insert "value is shown ")
693 (insert-button "below"
694 'action help-button-cache
696 'help-echo "mouse-2, RET: show value")
700 (let* ((alias (condition-case nil
701 (indirect-variable variable)
703 (obsolete (get variable 'byte-obsolete-variable))
705 (safe-var (get variable 'safe-local-variable))
706 (doc (or (documentation-property variable 'variable-documentation)
707 (documentation-property alias 'variable-documentation)))
709 ;; Add a note for variables that have been make-var-buffer-local.
710 (when (and (local-variable-if-set-p variable)
711 (or (not (local-variable-p variable))
713 (local-variable-if-set-p variable))))
715 (princ " Automatically becomes buffer-local when set in any fashion.\n"))
717 ;; Mention if it's an alias
718 (unless (eq alias variable)
720 (princ (format " This variable is an alias for `%s'.\n" alias)))
724 (princ " This variable is obsolete")
725 (if (cdr obsolete) (princ (format " since %s" (cdr obsolete))))
726 (princ (cond ((stringp use) (concat ";\n " use))
727 (use (format ";\n use `%s' instead." (car obsolete)))
731 (when (member (cons variable val) file-local-variables-alist)
733 (if (member (cons variable val) dir-local-variables-alist)
734 (let ((file (and (buffer-file-name)
735 (not (file-remote-p (buffer-file-name)))
736 (dir-locals-find-file (buffer-file-name)))))
737 (princ " This variable is a directory local variable")
739 (princ (concat "\n from the file \""
745 (princ " This variable is a file local variable.\n")))
747 (when (memq variable ignored-local-variables)
749 (princ " This variable is ignored when used as a file local \
752 ;; Can be both risky and safe, eg auto-fill-function.
753 (when (risky-local-variable-p variable)
755 (princ " This variable is potentially risky when used as a \
756 file local variable.\n")
757 (when (assq variable safe-local-variable-values)
758 (princ " However, you have added it to \
759 `safe-local-variable-values'.\n")))
763 (princ " This variable is safe as a file local variable ")
764 (princ "if its value\n satisfies the predicate ")
765 (princ (if (byte-code-function-p safe-var)
766 "which is byte-compiled expression.\n"
767 (format "`%s'.\n" safe-var))))
769 (if extra-line (terpri))
770 (princ "Documentation:\n")
771 (with-current-buffer standard-output
772 (insert (or doc "Not documented as a variable."))))
774 ;; Make a link to customize if this variable can be customized.
775 (when (custom-variable-p variable)
776 (let ((customize-label "customize"))
779 (princ (concat "You can " customize-label " this variable."))
780 (with-current-buffer standard-output
783 (concat "\\(" customize-label "\\)") nil t)
784 (help-xref-button 1 'help-customize-variable variable))))
785 ;; Note variable's version or package version
786 (let ((output (describe-variable-custom-version-info variable)))
793 (set-buffer standard-output)
794 ;; Return the text we displayed.
795 (buffer-string))))))))
799 (defun describe-syntax (&optional buffer)
800 "Describe the syntax specifications in the syntax table of BUFFER.
801 The descriptions are inserted in a help buffer, which is then displayed.
802 BUFFER defaults to the current buffer."
804 (setq buffer (or buffer (current-buffer)))
805 (help-setup-xref (list #'describe-syntax buffer)
806 (called-interactively-p 'interactive))
807 (with-help-window (help-buffer)
808 (let ((table (with-current-buffer buffer (syntax-table))))
809 (with-current-buffer standard-output
810 (describe-vector table 'internal-describe-syntax-value)
811 (while (setq table (char-table-parent table))
812 (insert "\nThe parent syntax table is:")
813 (describe-vector table 'internal-describe-syntax-value))))))
815 (defun help-describe-category-set (value)
817 ((null value) "default")
818 ((char-table-p value) "deeper char-table ...")
819 (t (condition-case err
820 (category-set-mnemonics value)
821 (error "invalid"))))))
824 (defun describe-categories (&optional buffer)
825 "Describe the category specifications in the current category table.
826 The descriptions are inserted in a buffer, which is then displayed.
827 If BUFFER is non-nil, then describe BUFFER's category table instead.
828 BUFFER should be a buffer or a buffer name."
830 (setq buffer (or buffer (current-buffer)))
831 (help-setup-xref (list #'describe-categories buffer)
832 (called-interactively-p 'interactive))
833 (with-help-window (help-buffer)
834 (let* ((table (with-current-buffer buffer (category-table)))
835 (docs (char-table-extra-slot table 0)))
836 (if (or (not (vectorp docs)) (/= (length docs) 95))
837 (error "Invalid first extra slot in this category table\n"))
838 (with-current-buffer standard-output
839 (insert "Legend of category mnemonics (see the tail for the longer description)\n")
840 (let ((pos (point)) (items 0) lines n)
842 (if (aref docs i) (setq items (1+ items))))
843 (setq lines (1+ (/ (1- items) 4)))
846 (let ((elt (aref docs i)))
848 (string-match ".*" elt)
849 (setq elt (match-string 0 elt))
850 (if (>= (length elt) 17)
851 (setq elt (concat (substring elt 0 14) "...")))
852 (if (< (point) (point-max))
853 (move-to-column (* 20 (/ n lines)) t))
854 (insert (+ i ?\s) ?: elt)
855 (if (< (point) (point-max))
859 (if (= (% n lines) 0)
861 (goto-char (point-max))
863 "character(s)\tcategory mnemonics\n"
864 "------------\t------------------")
865 (describe-vector table 'help-describe-category-set)
866 (insert "Legend of category mnemonics:\n")
868 (let ((elt (aref docs i)))
870 (if (string-match "\n" elt)
871 (setq elt (substring elt (match-end 0))))
872 (insert (+ i ?\s) ": " elt "\n"))))
873 (while (setq table (char-table-parent table))
874 (insert "\nThe parent category table is:")
875 (describe-vector table 'help-describe-category-set))))))
879 ;; arch-tag: 9e10331c-ae81-4d13-965d-c4819aaab0b3
880 ;;; help-fns.el ends here