1 ;;; help-fns.el --- Complex help functions -*- lexical-binding: t -*-
3 ;; Copyright (C) 1985-1986, 1993-1994, 1998-2012
4 ;; Free Software Foundation, Inc.
7 ;; 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
38 (defun describe-function (function)
39 "Display the full documentation of FUNCTION (a symbol)."
41 (let ((fn (function-called-at-point))
42 (enable-recursive-minibuffers t)
44 (setq val (completing-read (if fn
45 (format "Describe function (default %s): " fn)
46 "Describe function: ")
47 obarray 'fboundp t nil nil
48 (and fn (symbol-name fn))))
49 (list (if (equal val "")
52 (message "You didn't specify a function")
53 (help-setup-xref (list #'describe-function function)
54 (called-interactively-p 'interactive))
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, where USAGE info
69 is a string describing the argument list of DEF, such as
70 \"(apply FUNCTION &rest ARGUMENTS)\".
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 (unless (zerop (match-beginning 0))
82 (substring docstring 0 (match-beginning 0))))))
84 ;; FIXME: Move to subr.el?
85 (defun help-add-fundoc-usage (docstring arglist)
86 "Add the usage info to DOCSTRING.
87 If DOCSTRING already has a usage info, then just return it unchanged.
88 The usage info is built from ARGLIST. DOCSTRING can be nil.
89 ARGLIST can also be t or a string of the form \"(FUN ARG1 ARG2 ...)\"."
90 (unless (stringp docstring) (setq docstring ""))
91 (if (or (string-match "\n\n(fn\\(\\( .*\\)?)\\)\\'" docstring)
95 (if (string-match "\n?\n\\'" docstring)
96 (if (< (- (match-end 0) (match-beginning 0)) 2) "\n" "")
98 (if (and (stringp arglist)
99 (string-match "\\`([^ ]+\\(.*\\))\\'" arglist))
100 (concat "(fn" (match-string 1 arglist) ")")
101 (format "%S" (help-make-usage 'fn arglist))))))
103 ;; FIXME: Move to subr.el?
104 (defun help-function-arglist (def &optional preserve-names)
105 "Return a formal argument list for the function DEF.
106 IF PRESERVE-NAMES is non-nil, return a formal arglist that uses
107 the same names as used in the original source code, when possible."
108 ;; Handle symbols aliased to other symbols.
109 (if (and (symbolp def) (fboundp def)) (setq def (indirect-function def)))
110 ;; If definition is a macro, find the function inside it.
111 (if (eq (car-safe def) 'macro) (setq def (cdr def)))
113 ((and (byte-code-function-p def) (listp (aref def 0))) (aref def 0))
114 ((eq (car-safe def) 'lambda) (nth 1 def))
115 ((eq (car-safe def) 'closure) (nth 2 def))
116 ((or (and (byte-code-function-p def) (integerp (aref def 0)))
118 (or (when preserve-names
119 (let* ((doc (condition-case nil (documentation def) (error nil)))
120 (docargs (if doc (car (help-split-fundoc doc nil))))
122 (cdar (read-from-string (downcase docargs)))))
125 (dolist (arg arglist)
126 (unless (and (symbolp arg)
127 (let ((name (symbol-name arg)))
128 (if (eq (aref name 0) ?&)
129 (memq arg '(&rest &optional))
130 (not (string-match "\\." name)))))
132 (when valid arglist)))
133 (let* ((args-desc (if (not (subrp def))
135 (let ((a (subr-arity def)))
137 (if (numberp (cdr a))
140 (max (lsh args-desc -8))
141 (min (logand args-desc 127))
142 (rest (logand args-desc 128))
145 (push (intern (concat "arg" (number-to-string (1+ i)))) arglist))
147 (push '&optional arglist)
148 (dotimes (i (- max min))
149 (push (intern (concat "arg" (number-to-string (+ 1 i min))))
151 (unless (zerop rest) (push '&rest arglist) (push 'rest arglist))
152 (nreverse arglist))))
153 ((and (autoloadp def) (not (eq (nth 4 def) 'keymap)))
154 "[Arg list not available until function definition is loaded.]")
157 ;; FIXME: Move to subr.el?
158 (defun help-make-usage (function arglist)
159 (cons (if (symbolp function) function 'anonymous)
160 (mapcar (lambda (arg)
161 (if (not (symbolp arg)) arg
162 (let ((name (symbol-name arg)))
164 ((string-match "\\`&" name) arg)
165 ((string-match "\\`_" name)
166 (intern (upcase (substring name 1))))
167 (t (intern (upcase name)))))))
170 ;; Could be this, if we make symbol-file do the work below.
171 ;; (defun help-C-file-name (subr-or-var kind)
172 ;; "Return the name of the C file where SUBR-OR-VAR is defined.
173 ;; KIND should be `var' for a variable or `subr' for a subroutine."
174 ;; (symbol-file (if (symbolp subr-or-var) subr-or-var
175 ;; (subr-name subr-or-var))
176 ;; (if (eq kind 'var) 'defvar 'defun)))
178 (defun help-C-file-name (subr-or-var kind)
179 "Return the name of the C file where SUBR-OR-VAR is defined.
180 KIND should be `var' for a variable or `subr' for a subroutine."
181 (let ((docbuf (get-buffer-create " *DOC*"))
182 (name (if (eq 'var kind)
183 (concat "V" (symbol-name subr-or-var))
184 (concat "F" (subr-name subr-or-var)))))
185 (with-current-buffer docbuf
186 (goto-char (point-min))
188 (insert-file-contents-literally
189 (expand-file-name internal-doc-file-name doc-directory)))
190 (let ((file (catch 'loop
192 (let ((pnt (search-forward (concat "
\1f" name "\n"))))
193 (re-search-backward "
\1fS\\(.*\\)")
194 (let ((file (match-string 1)))
195 (if (member file build-files)
197 (goto-char pnt))))))))
198 (if (string-match "^ns.*\\(\\.o\\|obj\\)\\'" file)
199 (setq file (replace-match ".m" t t file 1))
200 (if (string-match "\\.\\(o\\|obj\\)\\'" file)
201 (setq file (replace-match ".c" t t file))))
202 (if (string-match "\\.\\(c\\|m\\)\\'" file)
206 (defcustom help-downcase-arguments nil
207 "If non-nil, argument names in *Help* buffers are downcased."
212 (defun help-highlight-arg (arg)
213 "Highlight ARG as an argument name for a *Help* buffer.
214 Return ARG in face `help-argument-name'; ARG is also downcased
215 if the variable `help-downcase-arguments' is non-nil."
216 (propertize (if help-downcase-arguments (downcase arg) arg)
217 'face 'help-argument-name))
219 (defun help-do-arg-highlight (doc args)
220 (with-syntax-table (make-syntax-table emacs-lisp-mode-syntax-table)
221 (modify-syntax-entry ?\- "w")
223 (setq doc (replace-regexp-in-string
224 ;; This is heuristic, but covers all common cases
226 (concat "\\<" ; beginning of word
227 "\\(?:[a-z-]*-\\)?" ; for xxx-ARG
231 "\\(?:es\\|s\\|th\\)?" ; for ARGth, ARGs
232 "\\(?:-[a-z0-9-]+\\)?" ; for ARG-xxx, ARG-n
233 "\\(?:-[{([<`\"].*?\\)?"; for ARG-{x}, (x), <x>, [x], `x'
235 (help-highlight-arg arg)
239 (defun help-highlight-arguments (usage doc &rest args)
240 (when (and usage (string-match "^(" usage))
243 (goto-char (point-min))
244 (let ((case-fold-search nil)
245 (next (not (or args (looking-at "\\["))))
247 ;; Make a list of all arguments
248 (skip-chars-forward "^ ")
250 (or opt (not (looking-at " &")) (setq opt t))
251 (if (not (re-search-forward " \\([\\[(]*\\)\\([^] &)\.]+\\)" nil t))
253 (setq args (cons (match-string 2) args))
254 (when (and opt (string= (match-string 1) "("))
255 ;; A pesky CL-style optional argument with default value,
256 ;; so let's skip over it
257 (search-backward "(")
258 (goto-char (scan-sexps (point) 1)))))
259 ;; Highlight arguments in the USAGE string
260 (setq usage (help-do-arg-highlight (buffer-string) args))
261 ;; Highlight arguments in the DOC string
262 (setq doc (and doc (help-do-arg-highlight doc args))))))
263 ;; Return value is like the one from help-split-fundoc, but highlighted
266 ;; The following function was compiled from the former functions
267 ;; `describe-simplify-lib-file-name' and `find-source-lisp-file' with
268 ;; some excerpts from `describe-function-1' and `describe-variable'.
269 ;; The only additional twists provided are (1) locate the defining file
270 ;; for autoloaded functions, and (2) give preference to files in the
271 ;; "install directory" (directories found via `load-path') rather than
272 ;; to files in the "compile directory" (directories found by searching
273 ;; the loaddefs.el file). We autoload it because it's also used by
274 ;; `describe-face' (instead of `describe-simplify-lib-file-name').
277 (defun find-lisp-object-file-name (object type)
278 "Guess the file that defined the Lisp object OBJECT, of type TYPE.
279 OBJECT should be a symbol associated with a function, variable, or face;
280 alternatively, it can be a function definition.
281 If TYPE is `defvar', search for a variable definition.
282 If TYPE is `defface', search for a face definition.
283 If TYPE is the value returned by `symbol-function' for a function symbol,
284 search for a function definition.
286 The return value is the absolute name of a readable file where OBJECT is
287 defined. If several such files exist, preference is given to a file
288 found via `load-path'. The return value can also be `C-source', which
289 means that OBJECT is a function or variable defined in C. If no
290 suitable file is found, return nil."
291 (let* ((autoloaded (autoloadp type))
292 (file-name (or (and autoloaded (nth 1 type))
294 object (if (memq type (list 'defvar 'defface))
299 ;; An autoloaded function: Locate the file since `symbol-function'
300 ;; has only returned a bare string here.
302 (locate-file file-name load-path '(".el" ".elc") 'readable)))
303 ((and (stringp file-name)
304 (string-match "[.]*loaddefs.el\\'" file-name))
305 ;; An autoloaded variable or face. Visit loaddefs.el in a buffer
306 ;; and try to extract the defining file. The following form is
307 ;; from `describe-function-1' and `describe-variable'.
310 (find-function-search-for-symbol object nil file-name)
313 (with-current-buffer (car location)
314 (goto-char (cdr location))
315 (when (re-search-backward
316 "^;;; Generated autoloads from \\(.*\\)" nil t)
319 (file-name-sans-extension
320 (match-string-no-properties 1))
321 load-path '(".el" ".elc") 'readable))))))))
324 ((and (not file-name) (subrp type))
325 ;; A built-in function. The form is from `describe-function-1'.
326 (if (get-buffer " *DOC*")
327 (help-C-file-name type 'subr)
329 ((and (not file-name) (symbolp object)
330 (integerp (get object 'variable-documentation)))
331 ;; A variable defined in C. The form is from `describe-variable'.
332 (if (get-buffer " *DOC*")
333 (help-C-file-name object 'var)
335 ((not (stringp file-name))
336 ;; If we don't have a file-name string by now, we lost.
338 ;; Now, `file-name' should have become an absolute file name.
339 ;; For files loaded from ~/.emacs.elc, try ~/.emacs.
341 (and (string-equal file-name
342 (expand-file-name ".emacs.elc" "~"))
343 (file-readable-p (setq fn (expand-file-name ".emacs" "~")))
345 ;; When the Elisp source file can be found in the install
346 ;; directory, return the name of that file.
348 (if (string-match "[.]elc\\'" file-name)
349 (substring-no-properties file-name 0 -1)
351 (or (and (file-readable-p lib-name) lib-name)
352 ;; The library might be compressed.
353 (and (file-readable-p (concat lib-name ".gz")) lib-name))))
354 ((let* ((lib-name (file-name-nondirectory file-name))
355 ;; The next form is from `describe-simplify-lib-file-name'.
357 ;; Try converting the absolute file name to a library
358 ;; name, convert that back to a file name and see if we
359 ;; get the original one. If so, they are equivalent.
360 (if (equal file-name (locate-file lib-name load-path '("")))
361 (if (string-match "[.]elc\\'" lib-name)
362 (substring-no-properties lib-name 0 -1)
365 ;; The next three forms are from `find-source-lisp-file'.
366 (elc-file (locate-file
368 (if (string-match "\\.el\\'" file-name)
371 load-path nil 'readable))
374 (insert-file-contents-literally elc-file nil 0 256)
377 (string-match ";;; from file \\(.*\\.el\\)" str)
378 (match-string 1 str))))
379 (and src-file (file-readable-p src-file) src-file))))))
381 (declare-function ad-get-advice-info "advice" (function))
383 (defun help-fns--key-bindings (function)
384 (when (commandp function)
385 (let ((pt2 (with-current-buffer standard-output (point)))
386 (remapped (command-remapping function)))
387 (unless (memq remapped '(ignore undefined))
388 (let ((keys (where-is-internal
389 (or remapped function) overriding-local-map nil nil))
391 (if (and (eq function 'self-insert-command)
392 (vectorp (car-safe keys))
393 (consp (aref (car keys) 0)))
394 (princ "It is bound to many ordinary text characters.\n")
395 ;; Which non-control non-meta keys run this command?
397 (if (member (event-modifiers (aref key 0)) '(nil (shift)))
398 (push key non-modified-keys)))
400 (princ "Its keys are remapped to ")
401 (princ (if (symbolp remapped)
402 (concat "`" (symbol-name remapped) "'")
403 "an anonymous command"))
408 "Without this remapping, it would be bound to "
410 ;; If lots of ordinary text characters run this command,
411 ;; don't mention them one by one.
412 (if (< (length non-modified-keys) 10)
413 (princ (mapconcat 'key-description keys ", "))
414 (dolist (key non-modified-keys)
415 (setq keys (delq key keys)))
418 (princ (mapconcat 'key-description keys ", "))
419 (princ ", and many ordinary text characters"))
420 (princ "many ordinary text characters"))))
421 (when (or remapped keys non-modified-keys)
425 (with-current-buffer standard-output
426 (fill-region-as-paragraph pt2 (point))
427 (unless (looking-back "\n\n")
430 (defun help-fns--compiler-macro (function)
431 (let ((handler (function-get function 'compiler-macro)))
433 (insert "\nThis function has a compiler macro")
434 (let ((lib (get function 'compiler-macro-file)))
435 ;; FIXME: rather than look at the compiler-macro-file property,
436 ;; just look at `handler' itself.
438 (insert (format " in `%s'" lib))
440 (re-search-backward "`\\([^`']+\\)'" nil t)
441 (help-xref-button 1 'help-function-cmacro function lib))))
444 (defun help-fns--signature (function doc real-def real-function)
445 (unless (keymapp function) ; If definition is a keymap, skip arglist note.
446 (let* ((advertised (gethash real-def advertised-signature-table t))
447 (arglist (if (listp advertised)
448 advertised (help-function-arglist real-def)))
449 (usage (help-split-fundoc doc function)))
450 (if usage (setq doc (cdr usage)))
452 ((and usage (not (listp advertised))) (car usage))
454 (format "%S" (help-make-usage function arglist)))
455 ((stringp arglist) arglist)
456 ;; Maybe the arglist is in the docstring of a symbol
457 ;; this one is aliased to.
458 ((let ((fun real-function))
459 (while (and (symbolp fun)
460 (setq fun (symbol-function fun))
461 (not (setq usage (help-split-fundoc
466 ((or (stringp real-def)
468 (format "\nMacro: %s" (format-kbd-macro real-def)))
469 (t "[Missing arglist. Please make a bug report.]")))
470 (high (help-highlight-arguments use doc)))
471 (let ((fill-begin (point)))
472 (insert (car high) "\n")
473 (fill-region fill-begin (point)))
476 (defun help-fns--parent-mode (function)
477 ;; If this is a derived mode, link to the parent.
478 (let ((parent-mode (and (symbolp function)
480 'derived-mode-parent))))
482 (insert "\nParent mode: `")
484 (insert (format "%s" parent-mode))
485 (make-text-button beg (point)
487 'help-args (list parent-mode)))
490 (defun help-fns--obsolete (function)
491 (let* ((obsolete (and
492 ;; `function' might be a lambda construct.
494 (get function 'byte-obsolete-info)))
495 (use (car obsolete)))
497 (insert "\nThis function is obsolete")
498 (when (nth 2 obsolete)
499 (insert (format " since %s" (nth 2 obsolete))))
500 (insert (cond ((stringp use) (concat ";\n" use))
501 (use (format ";\nuse `%s' instead." use))
505 ;; We could use `symbol-file' but this is a wee bit more efficient.
506 (defun help-fns--autoloaded-p (function file)
507 "Return non-nil if FUNCTION has previously been autoloaded.
508 FILE is the file where FUNCTION was probably defined."
509 (let* ((file (file-name-sans-extension (file-truename file)))
510 (load-hist load-history)
511 (target (cons t function))
513 (while (and load-hist (not found))
514 (and (caar load-hist)
515 (equal (file-name-sans-extension (caar load-hist)) file)
516 (setq found (member target (cdar load-hist))))
517 (setq load-hist (cdr load-hist)))
521 (defun describe-function-1 (function)
522 (let* ((advised (and (symbolp function) (featurep 'advice)
523 (ad-get-advice-info function)))
524 ;; If the function is advised, use the symbol that has the
525 ;; real definition, if that symbol is already set up.
528 (let ((origname (cdr (assq 'origname advised))))
529 (and (fboundp origname) origname)))
531 ;; Get the real definition.
532 (def (if (symbolp real-function)
533 (symbol-function real-function)
535 (aliased (symbolp def))
536 (real-def (if aliased
538 (while (and (fboundp f)
539 (symbolp (symbol-function f)))
540 (setq f (symbol-function f)))
543 (file-name (find-lisp-object-file-name function def))
544 (pt1 (with-current-buffer (help-buffer) (point)))
545 (beg (if (and (or (byte-code-function-p def)
547 (memq (car-safe def) '(macro lambda closure)))
549 (help-fns--autoloaded-p function file-name))
551 "an interactive autoloaded "
553 (if (commandp def) "an interactive " "a "))))
555 ;; Print what kind of function-like object FUNCTION is.
556 (princ (cond ((or (stringp def) (vectorp def))
559 (if (eq 'unevalled (cdr (subr-arity def)))
560 (concat beg "special form")
561 (concat beg "built-in function")))
562 ((byte-code-function-p def)
563 (concat beg "compiled Lisp function"))
565 (format "an alias for `%s'" real-def))
566 ((eq (car-safe def) 'lambda)
567 (concat beg "Lisp function"))
568 ((eq (car-safe def) 'macro)
569 (concat beg "Lisp macro"))
570 ((eq (car-safe def) 'closure)
571 (concat beg "Lisp closure"))
573 (format "%s autoloaded %s"
574 (if (commandp def) "an interactive" "an")
575 (if (eq (nth 4 def) 'keymap) "keymap"
576 (if (nth 4 def) "Lisp macro" "Lisp function"))))
579 (elts (cdr-safe def)))
581 (if (char-table-p (car-safe elts))
584 (setq elts (cdr-safe elts)))
585 (concat beg (if is-full "keymap" "sparse keymap"))))
588 (if (and aliased (not (fboundp real-def)))
589 (princ ",\nwhich is not defined. Please make a bug report.")
590 (with-current-buffer standard-output
593 (when (re-search-backward "alias for `\\([^`']+\\)'" nil t)
594 (help-xref-button 1 'help-function real-def)))))
598 ;; We used to add .el to the file name,
599 ;; but that's completely wrong when the user used load-file.
600 (princ (if (eq file-name 'C-source)
602 (file-name-nondirectory file-name)))
604 ;; Make a hyperlink to the library.
605 (with-current-buffer standard-output
607 (re-search-backward "`\\([^`']+\\)'" nil t)
608 (help-xref-button 1 'help-function-def function file-name))))
610 (with-current-buffer (help-buffer)
611 (fill-region-as-paragraph (save-excursion (goto-char pt1) (forward-line 0) (point))
615 (let* ((doc-raw (condition-case err
616 (documentation function t)
617 (error (format "No Doc! %S" err))))
618 ;; If the function is autoloaded, and its docstring has
619 ;; key substitution constructs, load the library.
621 (and (autoloadp real-def)
622 help-enable-auto-load
623 (string-match "\\([^\\]=\\|[^=]\\|\\`\\)\\\\[[{<]"
625 (load (cadr real-def) t))
626 (substitute-command-keys doc-raw))))
628 (help-fns--key-bindings function)
629 (with-current-buffer standard-output
630 (setq doc (help-fns--signature function doc real-def real-function))
632 (help-fns--compiler-macro function)
633 (help-fns--parent-mode function)
634 (help-fns--obsolete function)
637 (or doc "Not documented.")))))))
643 (defun variable-at-point (&optional any-symbol)
644 "Return the bound variable symbol found at or before point.
645 Return 0 if there is no such symbol.
646 If ANY-SYMBOL is non-nil, don't insist the symbol be bound."
647 (with-syntax-table emacs-lisp-mode-syntax-table
648 (or (condition-case ()
650 (skip-chars-forward "'")
651 (or (not (zerop (skip-syntax-backward "_w")))
652 (eq (char-syntax (following-char)) ?w)
653 (eq (char-syntax (following-char)) ?_)
655 (skip-chars-forward "'")
656 (let ((obj (read (current-buffer))))
657 (and (symbolp obj) (boundp obj) obj)))
659 (let* ((str (find-tag-default))
660 (sym (if str (intern-soft str))))
661 (if (and sym (or any-symbol (boundp sym)))
664 (when (and str (string-match "\\`\\W*\\(.*?\\)\\W*\\'" str))
665 (setq sym (intern-soft (match-string 1 str)))
666 (and (or any-symbol (boundp sym)) sym)))))
669 (defun describe-variable-custom-version-info (variable)
670 (let ((custom-version (get variable 'custom-version))
671 (cpv (get variable 'custom-package-version))
675 (format "This variable was introduced, or its default value was changed, in\nversion %s of Emacs.\n"
678 (let* ((package (car-safe cpv))
679 (version (if (listp (cdr-safe cpv))
682 (pkg-versions (assq package customize-package-emacs-version-alist))
683 (emacsv (cdr (assoc version pkg-versions))))
684 (if (and package version)
686 (format (concat "This variable was introduced, or its default value was changed, in\nversion %s of the %s package"
688 (format " that is part of Emacs %s" emacsv))
690 version package))))))
694 (defun describe-variable (variable &optional buffer frame)
695 "Display the full documentation of VARIABLE (a symbol).
696 Returns the documentation as a string, also.
697 If VARIABLE has a buffer-local value in BUFFER or FRAME
698 \(default to the current buffer and current frame),
699 it is displayed along with the global value."
701 (let ((v (variable-at-point))
702 (enable-recursive-minibuffers t)
704 (setq val (completing-read (if (symbolp v)
706 "Describe variable (default %s): " v)
707 "Describe variable: ")
710 (or (get vv 'variable-documentation)
711 (and (boundp vv) (not (keywordp vv)))))
713 (if (symbolp v) (symbol-name v))))
714 (list (if (equal val "")
717 (unless (buffer-live-p buffer) (setq buffer (current-buffer)))
718 (unless (frame-live-p frame) (setq frame (selected-frame)))
719 (if (not (symbolp variable))
720 (message "You did not specify a variable")
722 (let ((valvoid (not (with-current-buffer buffer (boundp variable))))
723 (permanent-local (get variable 'permanent-local))
724 val val-start-pos locus)
725 ;; Extract the value before setting up the output buffer,
726 ;; in case `buffer' *is* the output buffer.
728 (with-selected-frame frame
729 (with-current-buffer buffer
730 (setq val (symbol-value variable)
731 locus (variable-binding-locus variable)))))
732 (help-setup-xref (list #'describe-variable variable buffer)
733 (called-interactively-p 'interactive))
734 (with-help-window (help-buffer)
735 (with-current-buffer buffer
737 (setq file-name (find-lisp-object-file-name variable 'defvar))
741 (princ " is a variable defined in `")
742 (princ (if (eq file-name 'C-source)
744 (file-name-nondirectory file-name)))
746 (with-current-buffer standard-output
748 (re-search-backward "`\\([^`']+\\)'" nil t)
749 (help-xref-button 1 'help-variable-def
750 variable file-name)))
752 (princ "It is void as a variable.")
755 (princ " is void as a variable.")
758 (with-current-buffer standard-output
759 (setq val-start-pos (point))
762 (line-beg (line-beginning-position))
764 (let ((print-quoted t))
765 (prin1-to-string val))))
766 (if (< (+ (length print-rep) (point) (- line-beg)) 68)
770 (if (< (point) (+ 68 (line-beginning-position 0)))
771 (delete-region from (1+ from))
772 (delete-region (1- from) from)))
773 (let* ((sv (get variable 'standard-value))
774 (origval (and (consp sv)
777 (error :help-eval-error)))))
778 (when (and (consp sv)
779 (not (equal origval val))
780 (not (equal origval :help-eval-error)))
781 (princ "\nOriginal value was \n")
784 (if (< (point) (+ from 20))
785 (delete-region (1- from) from)))))))
790 (princ (format "Local in buffer %s; "
793 (princ (format "It is a frame-local variable; ")))
794 ((terminal-live-p locus)
795 (princ (format "It is a terminal-local variable; ")))
797 (princ (format "It is local to %S" locus))))
798 (if (not (default-boundp variable))
799 (princ "globally void")
800 (let ((global-val (default-value variable)))
801 (with-current-buffer standard-output
802 (princ "global value is ")
803 (if (eq val global-val)
806 ;; Fixme: pp can take an age if you happen to
807 ;; ask for a very large expression. We should
808 ;; probably print it raw once and check it's a
809 ;; sensible size before prettyprinting. -- fx
810 (let ((from (point)))
812 ;; See previous comment for this function.
813 ;; (help-xref-on-pp from (point))
814 (if (< (point) (+ from 20))
815 (delete-region (1- from) from)))))))
818 ;; If the value is large, move it to the end.
819 (with-current-buffer standard-output
820 (when (> (count-lines (point-min) (point-max)) 10)
821 ;; Note that setting the syntax table like below
822 ;; makes forward-sexp move over a `'s' at the end
824 (set-syntax-table emacs-lisp-mode-syntax-table)
825 (goto-char val-start-pos)
826 ;; The line below previously read as
827 ;; (delete-region (point) (progn (end-of-line) (point)))
828 ;; which suppressed display of the buffer local value for
830 (when (looking-at "value is") (replace-match ""))
832 (insert "\n\nValue:")
833 (set (make-local-variable 'help-button-cache)
835 (insert "value is shown ")
836 (insert-button "below"
837 'action help-button-cache
839 'help-echo "mouse-2, RET: show value")
843 (let* ((alias (condition-case nil
844 (indirect-variable variable)
846 (obsolete (get variable 'byte-obsolete-variable))
848 (safe-var (get variable 'safe-local-variable))
849 (doc (condition-case err
850 (or (documentation-property
851 variable 'variable-documentation)
852 (documentation-property
853 alias 'variable-documentation))
854 (error (format "Doc not found: %S" err))))
857 ;; Mention if it's a local variable.
859 ((and (local-variable-if-set-p variable)
860 (or (not (local-variable-p variable))
862 (local-variable-if-set-p variable))))
864 (princ " Automatically becomes ")
866 (princ "permanently "))
867 (princ "buffer-local when set.\n"))
868 ((not permanent-local))
870 (princ " This variable's buffer-local value is permanent.\n"))
872 (princ " This variable's value is permanent \
873 if it is given a local binding.\n")))
875 ;; Mention if it's an alias.
876 (unless (eq alias variable)
878 (princ (format " This variable is an alias for `%s'.\n" alias)))
882 (princ " This variable is obsolete")
884 (princ (format " since %s" (nth 2 obsolete))))
885 (princ (cond ((stringp use) (concat ";\n " use))
886 (use (format ";\n use `%s' instead." (car obsolete)))
890 (when (member (cons variable val) file-local-variables-alist)
892 (if (member (cons variable val) dir-local-variables-alist)
893 (let ((file (and (buffer-file-name)
894 (not (file-remote-p (buffer-file-name)))
895 (dir-locals-find-file
896 (buffer-file-name))))
898 (princ " This variable's value is directory-local")
902 (if (consp file) ; result from cache
903 ;; If the cache element has an mtime, we
904 ;; assume it came from a file.
906 (setq file (expand-file-name
907 dir-locals-file (car file)))
908 ;; Otherwise, assume it was set directly.
909 (setq dir-file nil)))
912 "for the directory\n `"))
913 (with-current-buffer standard-output
915 file 'type 'help-dir-local-var-def
916 'help-args (list variable file)))
918 (princ " This variable's value is file-local.\n")))
920 (when (memq variable ignored-local-variables)
922 (princ " This variable is ignored as a file-local \
925 ;; Can be both risky and safe, eg auto-fill-function.
926 (when (risky-local-variable-p variable)
928 (princ " This variable may be risky if used as a \
929 file-local variable.\n")
930 (when (assq variable safe-local-variable-values)
931 (princ " However, you have added it to \
932 `safe-local-variable-values'.\n")))
936 (princ " This variable is safe as a file local variable ")
937 (princ "if its value\n satisfies the predicate ")
938 (princ (if (byte-code-function-p safe-var)
939 "which is byte-compiled expression.\n"
940 (format "`%s'.\n" safe-var))))
942 (if extra-line (terpri))
943 (princ "Documentation:\n")
944 (with-current-buffer standard-output
945 (insert (or doc "Not documented as a variable."))))
947 ;; Make a link to customize if this variable can be customized.
948 (when (custom-variable-p variable)
949 (let ((customize-label "customize"))
952 (princ (concat "You can " customize-label " this variable."))
953 (with-current-buffer standard-output
956 (concat "\\(" customize-label "\\)") nil t)
957 (help-xref-button 1 'help-customize-variable variable))))
958 ;; Note variable's version or package version
959 (let ((output (describe-variable-custom-version-info variable)))
965 (with-current-buffer standard-output
966 ;; Return the text we displayed.
967 (buffer-string))))))))
971 (defun describe-syntax (&optional buffer)
972 "Describe the syntax specifications in the syntax table of BUFFER.
973 The descriptions are inserted in a help buffer, which is then displayed.
974 BUFFER defaults to the current buffer."
976 (setq buffer (or buffer (current-buffer)))
977 (help-setup-xref (list #'describe-syntax buffer)
978 (called-interactively-p 'interactive))
979 (with-help-window (help-buffer)
980 (let ((table (with-current-buffer buffer (syntax-table))))
981 (with-current-buffer standard-output
982 (describe-vector table 'internal-describe-syntax-value)
983 (while (setq table (char-table-parent table))
984 (insert "\nThe parent syntax table is:")
985 (describe-vector table 'internal-describe-syntax-value))))))
987 (defun help-describe-category-set (value)
989 ((null value) "default")
990 ((char-table-p value) "deeper char-table ...")
991 (t (condition-case nil
992 (category-set-mnemonics value)
993 (error "invalid"))))))
996 (defun describe-categories (&optional buffer)
997 "Describe the category specifications in the current category table.
998 The descriptions are inserted in a buffer, which is then displayed.
999 If BUFFER is non-nil, then describe BUFFER's category table instead.
1000 BUFFER should be a buffer or a buffer name."
1002 (setq buffer (or buffer (current-buffer)))
1003 (help-setup-xref (list #'describe-categories buffer)
1004 (called-interactively-p 'interactive))
1005 (with-help-window (help-buffer)
1006 (let* ((table (with-current-buffer buffer (category-table)))
1007 (docs (char-table-extra-slot table 0)))
1008 (if (or (not (vectorp docs)) (/= (length docs) 95))
1009 (error "Invalid first extra slot in this category table\n"))
1010 (with-current-buffer standard-output
1011 (insert "Legend of category mnemonics (see the tail for the longer description)\n")
1012 (let ((pos (point)) (items 0) lines n)
1014 (if (aref docs i) (setq items (1+ items))))
1015 (setq lines (1+ (/ (1- items) 4)))
1018 (let ((elt (aref docs i)))
1020 (string-match ".*" elt)
1021 (setq elt (match-string 0 elt))
1022 (if (>= (length elt) 17)
1023 (setq elt (concat (substring elt 0 14) "...")))
1024 (if (< (point) (point-max))
1025 (move-to-column (* 20 (/ n lines)) t))
1026 (insert (+ i ?\s) ?: elt)
1027 (if (< (point) (point-max))
1031 (if (= (% n lines) 0)
1032 (goto-char pos))))))
1033 (goto-char (point-max))
1035 "character(s)\tcategory mnemonics\n"
1036 "------------\t------------------")
1037 (describe-vector table 'help-describe-category-set)
1038 (insert "Legend of category mnemonics:\n")
1040 (let ((elt (aref docs i)))
1042 (if (string-match "\n" elt)
1043 (setq elt (substring elt (match-end 0))))
1044 (insert (+ i ?\s) ": " elt "\n"))))
1045 (while (setq table (char-table-parent table))
1046 (insert "\nThe parent category table is:")
1047 (describe-vector table 'help-describe-category-set))))))
1050 ;;; Replacements for old lib-src/ programs. Don't seem especially useful.
1052 ;; Replaces lib-src/digest-doc.c.
1054 (defun doc-file-to-man (file)
1055 "Produce an nroff buffer containing the doc-strings from the DOC file."
1056 (interactive (list (read-file-name "Name of DOC file: " doc-directory
1057 internal-doc-file-name t)))
1058 (or (file-readable-p file)
1059 (error "Cannot read file `%s'" file))
1060 (pop-to-buffer (generate-new-buffer "*man-doc*"))
1061 (setq buffer-undo-list t)
1062 (insert ".TH \"Command Summary for GNU Emacs\"\n"
1063 ".AU Richard M. Stallman\n")
1064 (insert-file-contents file)
1066 (while (search-forward "
\1f" nil 'move)
1067 (if (looking-at "S")
1068 (delete-region (1- (point)) (line-end-position))
1074 (insert (if (looking-at "F") "Function " "Variable "))
1077 (insert ".DS L\n"))))
1079 (setq buffer-undo-list nil)
1082 ;; Replaces lib-src/sorted-doc.c.
1084 (defun doc-file-to-info (file)
1085 "Produce a texinfo buffer with sorted doc-strings from the DOC file."
1086 (interactive (list (read-file-name "Name of DOC file: " doc-directory
1087 internal-doc-file-name t)))
1088 (or (file-readable-p file)
1089 (error "Cannot read file `%s'" file))
1090 (let ((i 0) type name doc alist)
1092 (insert-file-contents file)
1093 ;; The characters "@{}" need special treatment.
1094 (while (re-search-forward "[@{}]" nil t)
1098 (goto-char (point-min))
1099 (while (search-forward "
\1f" nil t)
1100 (unless (looking-at "S")
1101 (setq type (char-after)
1102 name (buffer-substring (1+ (point)) (line-end-position))
1103 doc (buffer-substring (line-beginning-position 2)
1104 (if (search-forward "
\1f" nil 'move)
1107 alist (cons (list name type doc) alist))
1108 (backward-char 1))))
1109 (pop-to-buffer (generate-new-buffer "*info-doc*"))
1110 (setq buffer-undo-list t)
1111 ;; Write the output header.
1112 (insert "\\input texinfo @c -*-texinfo-*-\n"
1113 "@setfilename emacsdoc.info\n"
1114 "@settitle Command Summary for GNU Emacs\n"
1117 "@unnumbered Command Summary for GNU Emacs\n\n"
1120 "@global@let@ITEM@item\n"
1121 "@def@item{@filbreak@vskip5pt@ITEM}\n"
1122 "@font@tensy cmsy10 scaled @magstephalf\n"
1123 "@font@teni cmmi10 scaled @magstephalf\n"
1124 "@def\\{{@tensy@char110}}\n" ; this backslash goes with cmr10
1125 "@def|{{@tensy@char106}}\n"
1126 "@def@{{{@tensy@char102}}\n"
1127 "@def@}{{@tensy@char103}}\n"
1128 "@def<{{@teni@char62}}\n"
1129 "@def>{{@teni@char60}}\n"
1132 "@tableindent-0.2in\n"
1134 ;; Sort the array by name; within each name, by type (functions first).
1135 (setq alist (sort alist (lambda (e1 e2)
1136 (if (string-equal (car e1) (car e2))
1137 (<= (cadr e1) (cadr e2))
1138 (string-lessp (car e1) (car e2))))))
1139 ;; Print each function.
1142 (if (char-equal (cadr e) ?\F) "Function" "Variable")
1143 " @code{" (car e) "}\n@display\n"
1146 ;; Try to avoid a save size overflow in the TeX output routine.
1147 (if (zerop (setq i (% (1+ i) 100)))
1148 (insert "\n@end table\n@table @asis\n")))
1149 (insert "@end table\n"
1151 (setq buffer-undo-list nil)
1156 ;;; help-fns.el ends here