1 ;;; help-fns.el --- Complex help functions
3 ;; Copyright (C) 1985-1986, 1993-1994, 1998-2011
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.
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 (unless (zerop (match-beginning 0))
80 (substring docstring
0 (match-beginning 0))))))
82 ;; FIXME: Move to subr.el?
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
""))
89 (if (or (string-match "\n\n(fn\\(\\( .*\\)?)\\)\\'" docstring
)
93 (if (string-match "\n?\n\\'" docstring
)
94 (if (< (- (match-end 0) (match-beginning 0)) 2) "\n" "")
96 (if (and (stringp arglist
)
97 (string-match "\\`([^ ]+\\(.*\\))\\'" arglist
))
98 (concat "(fn" (match-string 1 arglist
) ")")
99 (format "%S" (help-make-usage 'fn arglist
))))))
101 ;; FIXME: Move to subr.el?
102 (defun help-function-arglist (def)
103 ;; Handle symbols aliased to other symbols.
104 (if (and (symbolp def
) (fboundp def
)) (setq def
(indirect-function def
)))
105 ;; If definition is a macro, find the function inside it.
106 (if (eq (car-safe def
) 'macro
) (setq def
(cdr def
)))
108 ((and (byte-code-function-p def
) (integerp (aref def
0)))
109 (let* ((args-desc (aref def
0))
110 (max (lsh args-desc -
8))
111 (min (logand args-desc
127))
112 (rest (logand args-desc
128))
115 (push (intern (concat "arg" (number-to-string (1+ i
)))) arglist
))
117 (push '&optional arglist
)
118 (dotimes (i (- max min
))
119 (push (intern (concat "arg" (number-to-string (+ 1 i min
))))
121 (unless (zerop rest
) (push '&rest arglist
) (push 'rest arglist
))
123 ((byte-code-function-p def
) (aref def
0))
124 ((eq (car-safe def
) 'lambda
) (nth 1 def
))
125 ((eq (car-safe def
) 'closure
) (nth 2 def
))
127 (let ((arity (subr-arity def
))
129 (dotimes (i (car arity
))
130 (push (intern (concat "arg" (number-to-string (1+ i
)))) arglist
))
132 ((not (numberp (cdr arglist
)))
133 (push '&rest arglist
)
134 (push 'rest arglist
))
135 ((< (car arity
) (cdr arity
))
136 (push '&optional arglist
)
137 (dotimes (i (- (cdr arity
) (car arity
)))
138 (push (intern (concat "arg" (number-to-string
139 (+ 1 i
(car arity
)))))
142 ((and (eq (car-safe def
) 'autoload
) (not (eq (nth 4 def
) 'keymap
)))
143 "[Arg list not available until function definition is loaded.]")
146 ;; FIXME: Move to subr.el?
147 (defun help-make-usage (function arglist
)
148 (cons (if (symbolp function
) function
'anonymous
)
149 (mapcar (lambda (arg)
150 (if (not (symbolp arg
))
151 (if (and (consp arg
) (symbolp (car arg
)))
152 ;; CL style default values for optional args.
153 (cons (intern (upcase (symbol-name (car arg
))))
156 (let ((name (symbol-name arg
)))
158 ((string-match "\\`&" name
) arg
)
159 ((string-match "\\`_" name
)
160 (intern (upcase (substring name
1))))
161 (t (intern (upcase name
)))))))
164 ;; Could be this, if we make symbol-file do the work below.
165 ;; (defun help-C-file-name (subr-or-var kind)
166 ;; "Return the name of the C file where SUBR-OR-VAR is defined.
167 ;; KIND should be `var' for a variable or `subr' for a subroutine."
168 ;; (symbol-file (if (symbolp subr-or-var) subr-or-var
169 ;; (subr-name subr-or-var))
170 ;; (if (eq kind 'var) 'defvar 'defun)))
172 (defun help-C-file-name (subr-or-var kind
)
173 "Return the name of the C file where SUBR-OR-VAR is defined.
174 KIND should be `var' for a variable or `subr' for a subroutine."
175 (let ((docbuf (get-buffer-create " *DOC*"))
176 (name (if (eq 'var kind
)
177 (concat "V" (symbol-name subr-or-var
))
178 (concat "F" (subr-name subr-or-var
)))))
179 (with-current-buffer docbuf
180 (goto-char (point-min))
182 (insert-file-contents-literally
183 (expand-file-name internal-doc-file-name doc-directory
)))
184 (let ((file (catch 'loop
186 (let ((pnt (search-forward (concat "\x1f" name
"\n"))))
187 (re-search-backward "\x1fS\\(.*\\)")
188 (let ((file (match-string 1)))
189 (if (member file build-files
)
191 (goto-char pnt
))))))))
192 (if (string-match "^ns.*\\(\\.o\\|obj\\)\\'" file
)
193 (setq file
(replace-match ".m" t t file
1))
194 (if (string-match "\\.\\(o\\|obj\\)\\'" file
)
195 (setq file
(replace-match ".c" t t file
))))
196 (if (string-match "\\.\\(c\\|m\\)\\'" file
)
200 (defcustom help-downcase-arguments nil
201 "If non-nil, argument names in *Help* buffers are downcased."
206 (defun help-highlight-arg (arg)
207 "Highlight ARG as an argument name for a *Help* buffer.
208 Return ARG in face `help-argument-name'; ARG is also downcased
209 if the variable `help-downcase-arguments' is non-nil."
210 (propertize (if help-downcase-arguments
(downcase arg
) arg
)
211 'face
'help-argument-name
))
213 (defun help-do-arg-highlight (doc args
)
214 (with-syntax-table (make-syntax-table emacs-lisp-mode-syntax-table
)
215 (modify-syntax-entry ?\-
"w")
216 (dolist (arg args doc
)
217 (setq doc
(replace-regexp-in-string
218 ;; This is heuristic, but covers all common cases
220 (concat "\\<" ; beginning of word
221 "\\(?:[a-z-]*-\\)?" ; for xxx-ARG
225 "\\(?:es\\|s\\|th\\)?" ; for ARGth, ARGs
226 "\\(?:-[a-z0-9-]+\\)?" ; for ARG-xxx, ARG-n
227 "\\(?:-[{([<`\"].*?\\)?"; for ARG-{x}, (x), <x>, [x], `x'
229 (help-highlight-arg arg
)
232 (defun help-highlight-arguments (usage doc
&rest args
)
233 (when (and usage
(string-match "^(" usage
))
236 (goto-char (point-min))
237 (let ((case-fold-search nil
)
238 (next (not (or args
(looking-at "\\["))))
240 ;; Make a list of all arguments
241 (skip-chars-forward "^ ")
243 (or opt
(not (looking-at " &")) (setq opt t
))
244 (if (not (re-search-forward " \\([\\[(]*\\)\\([^] &)\.]+\\)" nil t
))
246 (setq args
(cons (match-string 2) args
))
247 (when (and opt
(string= (match-string 1) "("))
248 ;; A pesky CL-style optional argument with default value,
249 ;; so let's skip over it
250 (search-backward "(")
251 (goto-char (scan-sexps (point) 1)))))
252 ;; Highlight aguments in the USAGE string
253 (setq usage
(help-do-arg-highlight (buffer-string) args
))
254 ;; Highlight arguments in the DOC string
255 (setq doc
(and doc
(help-do-arg-highlight doc args
))))))
256 ;; Return value is like the one from help-split-fundoc, but highlighted
259 ;; The following function was compiled from the former functions
260 ;; `describe-simplify-lib-file-name' and `find-source-lisp-file' with
261 ;; some excerpts from `describe-function-1' and `describe-variable'.
262 ;; The only additional twists provided are (1) locate the defining file
263 ;; for autoloaded functions, and (2) give preference to files in the
264 ;; "install directory" (directories found via `load-path') rather than
265 ;; to files in the "compile directory" (directories found by searching
266 ;; the loaddefs.el file). We autoload it because it's also used by
267 ;; `describe-face' (instead of `describe-simplify-lib-file-name').
270 (defun find-lisp-object-file-name (object type
)
271 "Guess the file that defined the Lisp object OBJECT, of type TYPE.
272 OBJECT should be a symbol associated with a function, variable, or face;
273 alternatively, it can be a function definition.
274 If TYPE is `defvar', search for a variable definition.
275 If TYPE is `defface', search for a face definition.
276 If TYPE is the value returned by `symbol-function' for a function symbol,
277 search for a function definition.
279 The return value is the absolute name of a readable file where OBJECT is
280 defined. If several such files exist, preference is given to a file
281 found via `load-path'. The return value can also be `C-source', which
282 means that OBJECT is a function or variable defined in C. If no
283 suitable file is found, return nil."
284 (let* ((autoloaded (eq (car-safe type
) 'autoload
))
285 (file-name (or (and autoloaded
(nth 1 type
))
287 object
(if (memq type
(list 'defvar
'defface
))
292 ;; An autoloaded function: Locate the file since `symbol-function'
293 ;; has only returned a bare string here.
295 (locate-file file-name load-path
'(".el" ".elc") 'readable
)))
296 ((and (stringp file-name
)
297 (string-match "[.]*loaddefs.el\\'" file-name
))
298 ;; An autoloaded variable or face. Visit loaddefs.el in a buffer
299 ;; and try to extract the defining file. The following form is
300 ;; from `describe-function-1' and `describe-variable'.
303 (find-function-search-for-symbol object nil file-name
)
306 (with-current-buffer (car location
)
307 (goto-char (cdr location
))
308 (when (re-search-backward
309 "^;;; Generated autoloads from \\(.*\\)" nil t
)
312 (file-name-sans-extension
313 (match-string-no-properties 1))
314 load-path
'(".el" ".elc") 'readable
))))))))
317 ((and (not file-name
) (subrp type
))
318 ;; A built-in function. The form is from `describe-function-1'.
319 (if (get-buffer " *DOC*")
320 (help-C-file-name type
'subr
)
322 ((and (not file-name
) (symbolp object
)
323 (integerp (get object
'variable-documentation
)))
324 ;; A variable defined in C. The form is from `describe-variable'.
325 (if (get-buffer " *DOC*")
326 (help-C-file-name object
'var
)
328 ((not (stringp file-name
))
329 ;; If we don't have a file-name string by now, we lost.
331 ;; Now, `file-name' should have become an absolute file name.
332 ;; For files loaded from ~/.emacs.elc, try ~/.emacs.
334 (and (string-equal file-name
335 (expand-file-name ".emacs.elc" "~"))
336 (file-readable-p (setq fn
(expand-file-name ".emacs" "~")))
338 ;; When the Elisp source file can be found in the install
339 ;; directory, return the name of that file.
341 (if (string-match "[.]elc\\'" file-name
)
342 (substring-no-properties file-name
0 -
1)
344 (or (and (file-readable-p lib-name
) lib-name
)
345 ;; The library might be compressed.
346 (and (file-readable-p (concat lib-name
".gz")) lib-name
))))
347 ((let* ((lib-name (file-name-nondirectory file-name
))
348 ;; The next form is from `describe-simplify-lib-file-name'.
350 ;; Try converting the absolute file name to a library
351 ;; name, convert that back to a file name and see if we
352 ;; get the original one. If so, they are equivalent.
353 (if (equal file-name
(locate-file lib-name load-path
'("")))
354 (if (string-match "[.]elc\\'" lib-name
)
355 (substring-no-properties lib-name
0 -
1)
358 ;; The next three forms are from `find-source-lisp-file'.
359 (elc-file (locate-file
361 (if (string-match "\\.el\\'" file-name
)
364 load-path nil
'readable
))
367 (insert-file-contents-literally elc-file nil
0 256)
370 (string-match ";;; from file \\(.*\\.el\\)" str
)
371 (match-string 1 str
))))
372 (and src-file
(file-readable-p src-file
) src-file
))))))
374 (declare-function ad-get-advice-info
"advice" (function))
377 (defun describe-function-1 (function)
378 (let* ((advised (and (symbolp function
) (featurep 'advice
)
379 (ad-get-advice-info function
)))
380 ;; If the function is advised, use the symbol that has the
381 ;; real definition, if that symbol is already set up.
384 (let ((origname (cdr (assq 'origname advised
))))
385 (and (fboundp origname
) origname
)))
387 ;; Get the real definition.
388 (def (if (symbolp real-function
)
389 (symbol-function real-function
)
392 (beg (if (commandp def
) "an interactive " "a "))
393 (pt1 (with-current-buffer (help-buffer) (point)))
396 (cond ((or (stringp def
) (vectorp def
))
399 (if (eq 'unevalled
(cdr (subr-arity def
)))
400 (concat beg
"special form")
401 (concat beg
"built-in function")))
402 ((byte-code-function-p def
)
403 (concat beg
"compiled Lisp function"))
405 (while (and (fboundp def
)
406 (symbolp (symbol-function def
)))
407 (setq def
(symbol-function def
)))
408 ;; Handle (defalias 'foo 'bar), where bar is undefined.
409 (or (fboundp def
) (setq errtype
'alias
))
410 (format "an alias for `%s'" def
))
411 ((eq (car-safe def
) 'lambda
)
412 (concat beg
"Lisp function"))
413 ((eq (car-safe def
) 'macro
)
415 ((eq (car-safe def
) 'closure
)
416 (concat beg
"Lisp closure"))
417 ((eq (car-safe def
) 'autoload
)
418 (format "%s autoloaded %s"
419 (if (commandp def
) "an interactive" "an")
420 (if (eq (nth 4 def
) 'keymap
) "keymap"
421 (if (nth 4 def
) "Lisp macro" "Lisp function"))))
424 (elts (cdr-safe def
)))
426 (if (char-table-p (car-safe elts
))
429 (setq elts
(cdr-safe elts
)))
435 (if (eq errtype
'alias
)
436 (princ ",\nwhich is not defined. Please make a bug report.")
437 (with-current-buffer standard-output
440 (when (re-search-backward "alias for `\\([^`']+\\)'" nil t
)
441 (help-xref-button 1 'help-function def
)))))
443 (setq file-name
(find-lisp-object-file-name function def
))
446 ;; We used to add .el to the file name,
447 ;; but that's completely wrong when the user used load-file.
448 (princ (if (eq file-name
'C-source
)
450 (file-name-nondirectory file-name
)))
452 ;; Make a hyperlink to the library.
453 (with-current-buffer standard-output
455 (re-search-backward "`\\([^`']+\\)'" nil t
)
456 (help-xref-button 1 'help-function-def function file-name
))))
458 (with-current-buffer (help-buffer)
459 (fill-region-as-paragraph (save-excursion (goto-char pt1
) (forward-line 0) (point))
462 (when (commandp function
)
463 (let ((pt2 (with-current-buffer (help-buffer) (point)))
464 (remapped (command-remapping function
)))
465 (unless (memq remapped
'(ignore undefined
))
466 (let ((keys (where-is-internal
467 (or remapped function
) overriding-local-map nil nil
))
469 (if (and (eq function
'self-insert-command
)
470 (vectorp (car-safe keys
))
471 (consp (aref (car keys
) 0)))
472 (princ "It is bound to many ordinary text characters.\n")
473 ;; Which non-control non-meta keys run this command?
475 (if (member (event-modifiers (aref key
0)) '(nil (shift)))
476 (push key non-modified-keys
)))
478 (princ "It is remapped to `")
479 (princ (symbol-name remapped
))
483 (princ (if remapped
", which is bound to " "It is bound to "))
484 ;; If lots of ordinary text characters run this command,
485 ;; don't mention them one by one.
486 (if (< (length non-modified-keys
) 10)
487 (princ (mapconcat 'key-description keys
", "))
488 (dolist (key non-modified-keys
)
489 (setq keys
(delq key keys
)))
492 (princ (mapconcat 'key-description keys
", "))
493 (princ ", and many ordinary text characters"))
494 (princ "many ordinary text characters"))))
495 (when (or remapped keys non-modified-keys
)
499 (with-current-buffer (help-buffer)
500 (fill-region-as-paragraph pt2
(point))
501 (unless (looking-back "\n\n")
503 ;; Note that list* etc do not get this property until
504 ;; cl-hack-byte-compiler runs, after bytecomp is loaded.
505 (when (and (symbolp function
)
506 (eq (get function
'byte-compile
)
507 'cl-byte-compile-compiler-macro
))
508 (princ "This function has a compiler macro")
509 (let ((lib (get function
'compiler-macro-file
)))
511 (princ (format " in `%s'" lib
))
512 (with-current-buffer standard-output
514 (re-search-backward "`\\([^`']+\\)'" nil t
)
515 (help-xref-button 1 'help-function-cmacro function lib
)))))
517 (let* ((advertised (gethash def advertised-signature-table t
))
518 (arglist (if (listp advertised
)
519 advertised
(help-function-arglist def
)))
520 (doc (condition-case err
(documentation function
)
521 (error (format "No Doc! %S" err
))))
522 (usage (help-split-fundoc doc function
)))
523 (with-current-buffer standard-output
524 ;; If definition is a keymap, skip arglist note.
525 (unless (keymapp function
)
526 (if usage
(setq doc
(cdr usage
)))
528 ((and usage
(not (listp advertised
))) (car usage
))
530 (format "%S" (help-make-usage function arglist
)))
531 ((stringp arglist
) arglist
)
532 ;; Maybe the arglist is in the docstring of a symbol
533 ;; this one is aliased to.
534 ((let ((fun real-function
))
535 (while (and (symbolp fun
)
536 (setq fun
(symbol-function fun
))
537 (not (setq usage
(help-split-fundoc
544 (format "\nMacro: %s" (format-kbd-macro def
)))
545 (t "[Missing arglist. Please make a bug report.]")))
546 (high (help-highlight-arguments use doc
)))
547 (let ((fill-begin (point)))
548 (insert (car high
) "\n")
549 (fill-region fill-begin
(point)))
550 (setq doc
(cdr high
))))
551 (let* ((obsolete (and
552 ;; function might be a lambda construct.
554 (get function
'byte-obsolete-info
)))
555 (use (car obsolete
)))
557 (princ "\nThis function is obsolete")
558 (when (nth 2 obsolete
)
559 (insert (format " since %s" (nth 2 obsolete
))))
560 (insert (cond ((stringp use
) (concat ";\n" use
))
561 (use (format ";\nuse `%s' instead." use
))
565 (or doc
"Not documented."))))))))
571 (defun variable-at-point (&optional any-symbol
)
572 "Return the bound variable symbol found at or before point.
573 Return 0 if there is no such symbol.
574 If ANY-SYMBOL is non-nil, don't insist the symbol be bound."
575 (with-syntax-table emacs-lisp-mode-syntax-table
576 (or (condition-case ()
578 (skip-chars-forward "'")
579 (or (not (zerop (skip-syntax-backward "_w")))
580 (eq (char-syntax (following-char)) ?w
)
581 (eq (char-syntax (following-char)) ?_
)
583 (skip-chars-forward "'")
584 (let ((obj (read (current-buffer))))
585 (and (symbolp obj
) (boundp obj
) obj
)))
587 (let* ((str (find-tag-default))
588 (sym (if str
(intern-soft str
))))
589 (if (and sym
(or any-symbol
(boundp sym
)))
592 (when (and str
(string-match "\\`\\W*\\(.*?\\)\\W*\\'" str
))
593 (setq sym
(intern-soft (match-string 1 str
)))
594 (and (or any-symbol
(boundp sym
)) sym
)))))
597 (defun describe-variable-custom-version-info (variable)
598 (let ((custom-version (get variable
'custom-version
))
599 (cpv (get variable
'custom-package-version
))
603 (format "This variable was introduced, or its default value was changed, in\nversion %s of Emacs.\n"
606 (let* ((package (car-safe cpv
))
607 (version (if (listp (cdr-safe cpv
))
610 (pkg-versions (assq package customize-package-emacs-version-alist
))
611 (emacsv (cdr (assoc version pkg-versions
))))
612 (if (and package version
)
614 (format (concat "This variable was introduced, or its default value was changed, in\nversion %s of the %s package"
616 (format " that is part of Emacs %s" emacsv
))
618 version package
))))))
622 (defun describe-variable (variable &optional buffer frame
)
623 "Display the full documentation of VARIABLE (a symbol).
624 Returns the documentation as a string, also.
625 If VARIABLE has a buffer-local value in BUFFER or FRAME
626 \(default to the current buffer and current frame),
627 it is displayed along with the global value."
629 (let ((v (variable-at-point))
630 (enable-recursive-minibuffers t
)
632 (setq val
(completing-read (if (symbolp v
)
634 "Describe variable (default %s): " v
)
635 "Describe variable: ")
638 (or (special-variable-p vv
)
639 (get vv
'variable-documentation
)))
641 (if (symbolp v
) (symbol-name v
))))
642 (list (if (equal val
"")
645 (unless (buffer-live-p buffer
) (setq buffer
(current-buffer)))
646 (unless (frame-live-p frame
) (setq frame
(selected-frame)))
647 (if (not (symbolp variable
))
648 (message "You did not specify a variable")
650 (let ((valvoid (not (with-current-buffer buffer
(boundp variable
))))
651 val val-start-pos locus
)
652 ;; Extract the value before setting up the output buffer,
653 ;; in case `buffer' *is* the output buffer.
655 (with-selected-frame frame
656 (with-current-buffer buffer
657 (setq val
(symbol-value variable
)
658 locus
(variable-binding-locus variable
)))))
659 (help-setup-xref (list #'describe-variable variable buffer
)
660 (called-interactively-p 'interactive
))
661 (with-help-window (help-buffer)
662 (with-current-buffer buffer
664 (setq file-name
(find-lisp-object-file-name variable
'defvar
))
668 (princ " is a variable defined in `")
669 (princ (if (eq file-name
'C-source
)
671 (file-name-nondirectory file-name
)))
673 (with-current-buffer standard-output
675 (re-search-backward "`\\([^`']+\\)'" nil t
)
676 (help-xref-button 1 'help-variable-def
677 variable file-name
)))
679 (princ "It is void as a variable.")
682 (princ " is void as a variable.")
685 (with-current-buffer standard-output
686 (setq val-start-pos
(point))
688 (let ((from (point)))
691 (if (< (point) (+ 68 (line-beginning-position 0)))
692 (delete-region from
(1+ from
))
693 (delete-region (1- from
) from
))
694 (let* ((sv (get variable
'standard-value
))
695 (origval (and (consp sv
)
698 (error :help-eval-error
)))))
699 (when (and (consp sv
)
700 (not (equal origval val
))
701 (not (equal origval
:help-eval-error
)))
702 (princ "\nOriginal value was \n")
705 (if (< (point) (+ from
20))
706 (delete-region (1- from
) from
)))))))
710 (princ (format "%socal in buffer %s; "
711 (if (get variable
'permanent-local
)
714 (princ (format "It is a frame-local variable; ")))
715 (if (not (default-boundp variable
))
716 (princ "globally void")
717 (let ((val (default-value variable
)))
718 (with-current-buffer standard-output
719 (princ "global value is ")
721 ;; Fixme: pp can take an age if you happen to
722 ;; ask for a very large expression. We should
723 ;; probably print it raw once and check it's a
724 ;; sensible size before prettyprinting. -- fx
725 (let ((from (point)))
727 ;; See previous comment for this function.
728 ;; (help-xref-on-pp from (point))
729 (if (< (point) (+ from
20))
730 (delete-region (1- from
) from
))))))
733 ;; If the value is large, move it to the end.
734 (with-current-buffer standard-output
735 (when (> (count-lines (point-min) (point-max)) 10)
736 ;; Note that setting the syntax table like below
737 ;; makes forward-sexp move over a `'s' at the end
739 (set-syntax-table emacs-lisp-mode-syntax-table
)
740 (goto-char val-start-pos
)
741 ;; The line below previously read as
742 ;; (delete-region (point) (progn (end-of-line) (point)))
743 ;; which suppressed display of the buffer local value for
745 (when (looking-at "value is") (replace-match ""))
747 (insert "\n\nValue:")
748 (set (make-local-variable 'help-button-cache
)
750 (insert "value is shown ")
751 (insert-button "below"
752 'action help-button-cache
754 'help-echo
"mouse-2, RET: show value")
758 (let* ((alias (condition-case nil
759 (indirect-variable variable
)
761 (obsolete (get variable
'byte-obsolete-variable
))
763 (safe-var (get variable
'safe-local-variable
))
764 (doc (or (documentation-property variable
'variable-documentation
)
765 (documentation-property alias
'variable-documentation
)))
767 ;; Add a note for variables that have been make-var-buffer-local.
768 (when (and (local-variable-if-set-p variable
)
769 (or (not (local-variable-p variable
))
771 (local-variable-if-set-p variable
))))
773 (princ " Automatically becomes buffer-local when set in any fashion.\n"))
775 ;; Mention if it's an alias
776 (unless (eq alias variable
)
778 (princ (format " This variable is an alias for `%s'.\n" alias
)))
782 (princ " This variable is obsolete")
783 (if (cdr obsolete
) (princ (format " since %s" (cdr obsolete
))))
784 (princ (cond ((stringp use
) (concat ";\n " use
))
785 (use (format ";\n use `%s' instead." (car obsolete
)))
789 (when (member (cons variable val
) file-local-variables-alist
)
791 (if (member (cons variable val
) dir-local-variables-alist
)
792 (let ((file (and (buffer-file-name)
793 (not (file-remote-p (buffer-file-name)))
794 (dir-locals-find-file
795 (buffer-file-name))))
797 (princ " This variable is a directory local variable")
799 (if (consp file
) ; result from cache
800 ;; If the cache element has an mtime, we
801 ;; assume it came from a file.
803 (setq file
(expand-file-name
804 dir-locals-file
(car file
)))
805 ;; Otherwise, assume it was set directly.
806 (setq type
"directory")))
807 (princ (format "\n from the %s \"%s\"" type file
)))
809 (princ " This variable is a file local variable.\n")))
811 (when (memq variable ignored-local-variables
)
813 (princ " This variable is ignored when used as a file local \
816 ;; Can be both risky and safe, eg auto-fill-function.
817 (when (risky-local-variable-p variable
)
819 (princ " This variable is potentially risky when used as a \
820 file local variable.\n")
821 (when (assq variable safe-local-variable-values
)
822 (princ " However, you have added it to \
823 `safe-local-variable-values'.\n")))
827 (princ " This variable is safe as a file local variable ")
828 (princ "if its value\n satisfies the predicate ")
829 (princ (if (byte-code-function-p safe-var
)
830 "which is byte-compiled expression.\n"
831 (format "`%s'.\n" safe-var
))))
833 (if extra-line
(terpri))
834 (princ "Documentation:\n")
835 (with-current-buffer standard-output
836 (insert (or doc
"Not documented as a variable."))))
838 ;; Make a link to customize if this variable can be customized.
839 (when (custom-variable-p variable
)
840 (let ((customize-label "customize"))
843 (princ (concat "You can " customize-label
" this variable."))
844 (with-current-buffer standard-output
847 (concat "\\(" customize-label
"\\)") nil t
)
848 (help-xref-button 1 'help-customize-variable variable
))))
849 ;; Note variable's version or package version
850 (let ((output (describe-variable-custom-version-info variable
)))
856 (with-current-buffer standard-output
857 ;; Return the text we displayed.
858 (buffer-string))))))))
862 (defun describe-syntax (&optional buffer
)
863 "Describe the syntax specifications in the syntax table of BUFFER.
864 The descriptions are inserted in a help buffer, which is then displayed.
865 BUFFER defaults to the current buffer."
867 (setq buffer
(or buffer
(current-buffer)))
868 (help-setup-xref (list #'describe-syntax buffer
)
869 (called-interactively-p 'interactive
))
870 (with-help-window (help-buffer)
871 (let ((table (with-current-buffer buffer
(syntax-table))))
872 (with-current-buffer standard-output
873 (describe-vector table
'internal-describe-syntax-value
)
874 (while (setq table
(char-table-parent table
))
875 (insert "\nThe parent syntax table is:")
876 (describe-vector table
'internal-describe-syntax-value
))))))
878 (defun help-describe-category-set (value)
880 ((null value
) "default")
881 ((char-table-p value
) "deeper char-table ...")
882 (t (condition-case err
883 (category-set-mnemonics value
)
884 (error "invalid"))))))
887 (defun describe-categories (&optional buffer
)
888 "Describe the category specifications in the current category table.
889 The descriptions are inserted in a buffer, which is then displayed.
890 If BUFFER is non-nil, then describe BUFFER's category table instead.
891 BUFFER should be a buffer or a buffer name."
893 (setq buffer
(or buffer
(current-buffer)))
894 (help-setup-xref (list #'describe-categories buffer
)
895 (called-interactively-p 'interactive
))
896 (with-help-window (help-buffer)
897 (let* ((table (with-current-buffer buffer
(category-table)))
898 (docs (char-table-extra-slot table
0)))
899 (if (or (not (vectorp docs
)) (/= (length docs
) 95))
900 (error "Invalid first extra slot in this category table\n"))
901 (with-current-buffer standard-output
902 (insert "Legend of category mnemonics (see the tail for the longer description)\n")
903 (let ((pos (point)) (items 0) lines n
)
905 (if (aref docs i
) (setq items
(1+ items
))))
906 (setq lines
(1+ (/ (1- items
) 4)))
909 (let ((elt (aref docs i
)))
911 (string-match ".*" elt
)
912 (setq elt
(match-string 0 elt
))
913 (if (>= (length elt
) 17)
914 (setq elt
(concat (substring elt
0 14) "...")))
915 (if (< (point) (point-max))
916 (move-to-column (* 20 (/ n lines
)) t
))
917 (insert (+ i ?\s
) ?
: elt
)
918 (if (< (point) (point-max))
922 (if (= (% n lines
) 0)
924 (goto-char (point-max))
926 "character(s)\tcategory mnemonics\n"
927 "------------\t------------------")
928 (describe-vector table
'help-describe-category-set
)
929 (insert "Legend of category mnemonics:\n")
931 (let ((elt (aref docs i
)))
933 (if (string-match "\n" elt
)
934 (setq elt
(substring elt
(match-end 0))))
935 (insert (+ i ?\s
) ": " elt
"\n"))))
936 (while (setq table
(char-table-parent table
))
937 (insert "\nThe parent category table is:")
938 (describe-vector table
'help-describe-category-set
))))))
941 ;;; Replacements for old lib-src/ programs. Don't seem especially useful.
943 ;; Replaces lib-src/digest-doc.c.
945 (defun doc-file-to-man (file)
946 "Produce an nroff buffer containing the doc-strings from the DOC file."
947 (interactive (list (read-file-name "Name of DOC file: " doc-directory
948 internal-doc-file-name t
)))
949 (or (file-readable-p file
)
950 (error "Cannot read file `%s'" file
))
951 (pop-to-buffer (generate-new-buffer "*man-doc*"))
952 (setq buffer-undo-list t
)
953 (insert ".TH \"Command Summary for GNU Emacs\"\n"
954 ".AU Richard M. Stallman\n")
955 (insert-file-contents file
)
957 (while (search-forward "\x1f" nil
'move
)
959 (delete-region (1- (point)) (line-end-position))
965 (insert (if (looking-at "F") "Function " "Variable "))
968 (insert ".DS L\n"))))
970 (setq buffer-undo-list nil
)
973 ;; Replaces lib-src/sorted-doc.c.
975 (defun doc-file-to-info (file)
976 "Produce a texinfo buffer with sorted doc-strings from the DOC file."
977 (interactive (list (read-file-name "Name of DOC file: " doc-directory
978 internal-doc-file-name t
)))
979 (or (file-readable-p file
)
980 (error "Cannot read file `%s'" file
))
981 (let ((i 0) type name doc alist
)
983 (insert-file-contents file
)
984 ;; The characters "@{}" need special treatment.
985 (while (re-search-forward "[@{}]" nil t
)
989 (goto-char (point-min))
990 (while (search-forward "\x1f" nil t
)
991 (unless (looking-at "S")
992 (setq type
(char-after)
993 name
(buffer-substring (1+ (point)) (line-end-position))
994 doc
(buffer-substring (line-beginning-position 2)
995 (if (search-forward "\x1f" nil
'move
)
998 alist
(cons (list name type doc
) alist
))
1000 (pop-to-buffer (generate-new-buffer "*info-doc*"))
1001 (setq buffer-undo-list t
)
1002 ;; Write the output header.
1003 (insert "\\input texinfo @c -*-texinfo-*-\n"
1004 "@setfilename emacsdoc.info\n"
1005 "@settitle Command Summary for GNU Emacs\n"
1008 "@unnumbered Command Summary for GNU Emacs\n\n"
1011 "@global@let@ITEM@item\n"
1012 "@def@item{@filbreak@vskip5pt@ITEM}\n"
1013 "@font@tensy cmsy10 scaled @magstephalf\n"
1014 "@font@teni cmmi10 scaled @magstephalf\n"
1015 "@def\\{{@tensy@char110}}\n" ; this backslash goes with cmr10
1016 "@def|{{@tensy@char106}}\n"
1017 "@def@{{{@tensy@char102}}\n"
1018 "@def@}{{@tensy@char103}}\n"
1019 "@def<{{@teni@char62}}\n"
1020 "@def>{{@teni@char60}}\n"
1023 "@tableindent-0.2in\n"
1025 ;; Sort the array by name; within each name, by type (functions first).
1026 (setq alist
(sort alist
(lambda (e1 e2
)
1027 (if (string-equal (car e1
) (car e2
))
1028 (<= (cadr e1
) (cadr e2
))
1029 (string-lessp (car e1
) (car e2
))))))
1030 ;; Print each function.
1033 (if (char-equal (cadr e
) ?\F
) "Function" "Variable")
1034 " @code{" (car e
) "}\n@display\n"
1037 ;; Try to avoid a save size overflow in the TeX output routine.
1038 (if (zerop (setq i
(%
(1+ i
) 100)))
1039 (insert "\n@end table\n@table @asis\n")))
1040 (insert "@end table\n"
1042 (setq buffer-undo-list nil
)
1047 ;;; help-fns.el ends here