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 (substring docstring
0 (match-beginning 0)))))
81 (defun help-add-fundoc-usage (docstring arglist
)
82 "Add the usage info to DOCSTRING.
83 If DOCSTRING already has a usage info, then just return it unchanged.
84 The usage info is built from ARGLIST. DOCSTRING can be nil.
85 ARGLIST can also be t or a string of the form \"(FUN ARG1 ARG2 ...)\"."
86 (unless (stringp docstring
) (setq docstring
"Not documented"))
87 (if (or (string-match "\n\n(fn\\(\\( .*\\)?)\\)\\'" docstring
) (eq arglist t
))
90 (if (string-match "\n?\n\\'" docstring
)
91 (if (< (- (match-end 0) (match-beginning 0)) 2) "\n" "")
93 (if (and (stringp arglist
)
94 (string-match "\\`([^ ]+\\(.*\\))\\'" arglist
))
95 (concat "(fn" (match-string 1 arglist
) ")")
96 (format "%S" (help-make-usage 'fn arglist
))))))
98 (defun help-function-arglist (def)
99 ;; Handle symbols aliased to other symbols.
100 (if (and (symbolp def
) (fboundp def
)) (setq def
(indirect-function def
)))
101 ;; If definition is a macro, find the function inside it.
102 (if (eq (car-safe def
) 'macro
) (setq def
(cdr def
)))
103 ;; and do the same for interpreted closures
104 (if (eq (car-safe def
) 'closure
) (setq def
(cddr 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
)
195 (when (and usage
(string-match "^(" usage
))
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 `defvar', search for a variable definition.
237 If TYPE is `defface', 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.
293 ;; Now, `file-name' should have become an absolute file name.
294 ;; For files loaded from ~/.emacs.elc, try ~/.emacs.
296 (and (string-equal file-name
297 (expand-file-name ".emacs.elc" "~"))
298 (file-readable-p (setq fn
(expand-file-name ".emacs" "~")))
300 ;; When the Elisp source file can be found in the install
301 ;; directory, return the name of that file.
303 (if (string-match "[.]elc\\'" file-name
)
304 (substring-no-properties file-name
0 -
1)
306 (or (and (file-readable-p lib-name
) lib-name
)
307 ;; The library might be compressed.
308 (and (file-readable-p (concat lib-name
".gz")) lib-name
))))
309 ((let* ((lib-name (file-name-nondirectory file-name
))
310 ;; The next form is from `describe-simplify-lib-file-name'.
312 ;; Try converting the absolute file name to a library
313 ;; name, convert that back to a file name and see if we
314 ;; get the original one. If so, they are equivalent.
315 (if (equal file-name
(locate-file lib-name load-path
'("")))
316 (if (string-match "[.]elc\\'" lib-name
)
317 (substring-no-properties lib-name
0 -
1)
320 ;; The next three forms are from `find-source-lisp-file'.
321 (elc-file (locate-file
323 (if (string-match "\\.el\\'" file-name
)
326 load-path nil
'readable
))
329 (insert-file-contents-literally elc-file nil
0 256)
332 (string-match ";;; from file \\(.*\\.el\\)" str
)
333 (match-string 1 str
))))
334 (and src-file
(file-readable-p src-file
) src-file
))))))
336 (declare-function ad-get-advice-info
"advice" (function))
339 (defun describe-function-1 (function)
340 (let* ((advised (and (symbolp function
) (featurep 'advice
)
341 (ad-get-advice-info function
)))
342 ;; If the function is advised, use the symbol that has the
343 ;; real definition, if that symbol is already set up.
346 (let ((origname (cdr (assq 'origname advised
))))
347 (and (fboundp origname
) origname
)))
349 ;; Get the real definition.
350 (def (if (symbolp real-function
)
351 (symbol-function real-function
)
354 (beg (if (commandp def
) "an interactive " "a "))
355 (pt1 (with-current-buffer (help-buffer) (point)))
358 (cond ((or (stringp def
) (vectorp def
))
361 (if (eq 'unevalled
(cdr (subr-arity def
)))
362 (concat beg
"special form")
363 (concat beg
"built-in function")))
364 ((byte-code-function-p def
)
365 (concat beg
"compiled Lisp function"))
366 ((and (funvecp def
) (eq (aref def
0) 'curry
))
367 (if (symbolp (aref def
1))
368 (format "a curried function calling `%s'" (aref def
1))
369 "a curried function"))
371 (format "a function-vector (funvec) of type `%s'"
374 (while (and (fboundp def
)
375 (symbolp (symbol-function def
)))
376 (setq def
(symbol-function def
)))
377 ;; Handle (defalias 'foo 'bar), where bar is undefined.
378 (or (fboundp def
) (setq errtype
'alias
))
379 (format "an alias for `%s'" def
))
380 ((eq (car-safe def
) 'lambda
)
381 (concat beg
"Lisp function"))
382 ((eq (car-safe def
) 'macro
)
384 ((eq (car-safe def
) 'closure
)
385 (concat beg
"Lisp closure"))
386 ((eq (car-safe def
) 'autoload
)
387 (format "%s autoloaded %s"
388 (if (commandp def
) "an interactive" "an")
389 (if (eq (nth 4 def
) 'keymap
) "keymap"
390 (if (nth 4 def
) "Lisp macro" "Lisp function"))))
393 (elts (cdr-safe def
)))
395 (if (char-table-p (car-safe elts
))
398 (setq elts
(cdr-safe elts
)))
404 (if (eq errtype
'alias
)
405 (princ ",\nwhich is not defined. Please make a bug report.")
406 (with-current-buffer standard-output
409 (when (re-search-backward "alias for `\\([^`']+\\)'" nil t
)
410 (help-xref-button 1 'help-function def
)))))
412 (setq file-name
(find-lisp-object-file-name function def
))
415 ;; We used to add .el to the file name,
416 ;; but that's completely wrong when the user used load-file.
417 (princ (if (eq file-name
'C-source
)
419 (file-name-nondirectory file-name
)))
421 ;; Make a hyperlink to the library.
422 (with-current-buffer standard-output
424 (re-search-backward "`\\([^`']+\\)'" nil t
)
425 (help-xref-button 1 'help-function-def function file-name
))))
427 (with-current-buffer (help-buffer)
428 (fill-region-as-paragraph (save-excursion (goto-char pt1
) (forward-line 0) (point))
431 (when (commandp function
)
432 (let ((pt2 (with-current-buffer (help-buffer) (point)))
433 (remapped (command-remapping function
)))
434 (unless (memq remapped
'(ignore undefined
))
435 (let ((keys (where-is-internal
436 (or remapped function
) overriding-local-map nil nil
))
438 (if (and (eq function
'self-insert-command
)
439 (vectorp (car-safe keys
))
440 (consp (aref (car keys
) 0)))
441 (princ "It is bound to many ordinary text characters.\n")
442 ;; Which non-control non-meta keys run this command?
444 (if (member (event-modifiers (aref key
0)) '(nil (shift)))
445 (push key non-modified-keys
)))
447 (princ "It is remapped to `")
448 (princ (symbol-name remapped
))
452 (princ (if remapped
", which is bound to " "It is bound to "))
453 ;; If lots of ordinary text characters run this command,
454 ;; don't mention them one by one.
455 (if (< (length non-modified-keys
) 10)
456 (princ (mapconcat 'key-description keys
", "))
457 (dolist (key non-modified-keys
)
458 (setq keys
(delq key keys
)))
461 (princ (mapconcat 'key-description keys
", "))
462 (princ ", and many ordinary text characters"))
463 (princ "many ordinary text characters"))))
464 (when (or remapped keys non-modified-keys
)
468 (with-current-buffer (help-buffer)
469 (fill-region-as-paragraph pt2
(point))
470 (unless (looking-back "\n\n")
472 ;; Note that list* etc do not get this property until
473 ;; cl-hack-byte-compiler runs, after bytecomp is loaded.
474 (when (and (symbolp function
)
475 (eq (get function
'byte-compile
)
476 'cl-byte-compile-compiler-macro
))
477 (princ "This function has a compiler macro")
478 (let ((lib (get function
'compiler-macro-file
)))
480 (princ (format " in `%s'" lib
))
481 (with-current-buffer standard-output
483 (re-search-backward "`\\([^`']+\\)'" nil t
)
484 (help-xref-button 1 'help-function-cmacro function lib
)))))
486 (let* ((advertised (gethash def advertised-signature-table t
))
487 (arglist (if (listp advertised
)
488 advertised
(help-function-arglist def
)))
489 (doc (documentation function
))
490 (usage (help-split-fundoc doc function
)))
491 (with-current-buffer standard-output
492 ;; If definition is a keymap, skip arglist note.
493 (unless (keymapp function
)
494 (if usage
(setq doc
(cdr usage
)))
496 ((and usage
(not (listp advertised
))) (car usage
))
498 (format "%S" (help-make-usage function arglist
)))
499 ((stringp arglist
) arglist
)
500 ;; Maybe the arglist is in the docstring of a symbol
501 ;; this one is aliased to.
502 ((let ((fun real-function
))
503 (while (and (symbolp fun
)
504 (setq fun
(symbol-function fun
))
505 (not (setq usage
(help-split-fundoc
512 (format "\nMacro: %s" (format-kbd-macro def
)))
513 ((and (funvecp def
) (eq (aref def
0) 'curry
))
514 ;; Describe a curried-function's function and args
516 (mapconcat (lambda (arg)
517 (setq slot
(1+ slot
))
521 (format " Function: %S" arg
))
523 (format "Argument %d: %S"
528 (t "[Missing arglist. Please make a bug report.]")))
529 (high (help-highlight-arguments use doc
)))
530 (let ((fill-begin (point)))
531 (insert (car high
) "\n")
532 (fill-region fill-begin
(point))))
533 (setq doc
(cdr high
))))
534 (let* ((obsolete (and
535 ;; function might be a lambda construct.
537 (get function
'byte-obsolete-info
)))
538 (use (car obsolete
)))
540 (princ "\nThis function is obsolete")
541 (when (nth 2 obsolete
)
542 (insert (format " since %s" (nth 2 obsolete
))))
543 (insert (cond ((stringp use
) (concat ";\n" use
))
544 (use (format ";\nuse `%s' instead." use
))
548 (or doc
"Not documented.")))))))
554 (defun variable-at-point (&optional any-symbol
)
555 "Return the bound variable symbol found at or before point.
556 Return 0 if there is no such symbol.
557 If ANY-SYMBOL is non-nil, don't insist the symbol be bound."
558 (with-syntax-table emacs-lisp-mode-syntax-table
559 (or (condition-case ()
561 (or (not (zerop (skip-syntax-backward "_w")))
562 (eq (char-syntax (following-char)) ?w
)
563 (eq (char-syntax (following-char)) ?_
)
565 (skip-chars-forward "'")
566 (let ((obj (read (current-buffer))))
567 (and (symbolp obj
) (boundp obj
) obj
)))
569 (let* ((str (find-tag-default))
570 (sym (if str
(intern-soft str
))))
571 (if (and sym
(or any-symbol
(boundp sym
)))
574 (when (and str
(string-match "\\`\\W*\\(.*?\\)\\W*\\'" str
))
575 (setq sym
(intern-soft (match-string 1 str
)))
576 (and (or any-symbol
(boundp sym
)) sym
)))))
579 (defun describe-variable-custom-version-info (variable)
580 (let ((custom-version (get variable
'custom-version
))
581 (cpv (get variable
'custom-package-version
))
585 (format "This variable was introduced, or its default value was changed, in\nversion %s of Emacs.\n"
588 (let* ((package (car-safe cpv
))
589 (version (if (listp (cdr-safe cpv
))
592 (pkg-versions (assq package customize-package-emacs-version-alist
))
593 (emacsv (cdr (assoc version pkg-versions
))))
594 (if (and package version
)
596 (format (concat "This variable was introduced, or its default value was changed, in\nversion %s of the %s package"
598 (format " that is part of Emacs %s" emacsv
))
600 version package
))))))
604 (defun describe-variable (variable &optional buffer frame
)
605 "Display the full documentation of VARIABLE (a symbol).
606 Returns the documentation as a string, also.
607 If VARIABLE has a buffer-local value in BUFFER or FRAME
608 \(default to the current buffer and current frame),
609 it is displayed along with the global value."
611 (let ((v (variable-at-point))
612 (enable-recursive-minibuffers t
)
614 (setq val
(completing-read (if (symbolp v
)
616 "Describe variable (default %s): " v
)
617 "Describe variable: ")
621 (get vv
'variable-documentation
)))
623 (if (symbolp v
) (symbol-name v
))))
624 (list (if (equal val
"")
627 (unless (buffer-live-p buffer
) (setq buffer
(current-buffer)))
628 (unless (frame-live-p frame
) (setq frame
(selected-frame)))
629 (if (not (symbolp variable
))
630 (message "You did not specify a variable")
632 (let ((valvoid (not (with-current-buffer buffer
(boundp variable
))))
633 val val-start-pos locus
)
634 ;; Extract the value before setting up the output buffer,
635 ;; in case `buffer' *is* the output buffer.
637 (with-selected-frame frame
638 (with-current-buffer buffer
639 (setq val
(symbol-value variable
)
640 locus
(variable-binding-locus variable
)))))
641 (help-setup-xref (list #'describe-variable variable buffer
)
642 (called-interactively-p 'interactive
))
643 (with-help-window (help-buffer)
644 (with-current-buffer buffer
646 (setq file-name
(find-lisp-object-file-name variable
'defvar
))
650 (princ " is a variable defined in `")
651 (princ (if (eq file-name
'C-source
)
653 (file-name-nondirectory file-name
)))
655 (with-current-buffer standard-output
657 (re-search-backward "`\\([^`']+\\)'" nil t
)
658 (help-xref-button 1 'help-variable-def
659 variable file-name
)))
661 (princ "It is void as a variable.")
664 (princ " is void as a variable.")
667 (with-current-buffer standard-output
668 (setq val-start-pos
(point))
670 (let ((from (point)))
673 (if (< (point) (+ 68 (line-beginning-position 0)))
674 (delete-region from
(1+ from
))
675 (delete-region (1- from
) from
))
676 (let* ((sv (get variable
'standard-value
))
677 (origval (and (consp sv
)
680 (error :help-eval-error
)))))
681 (when (and (consp sv
)
682 (not (equal origval val
))
683 (not (equal origval
:help-eval-error
)))
684 (princ "\nOriginal value was \n")
687 (if (< (point) (+ from
20))
688 (delete-region (1- from
) from
)))))))
692 (princ (format "%socal in buffer %s; "
693 (if (get variable
'permanent-local
)
696 (princ (format "It is a frame-local variable; ")))
697 (if (not (default-boundp variable
))
698 (princ "globally void")
699 (let ((val (default-value variable
)))
700 (with-current-buffer standard-output
701 (princ "global value is ")
703 ;; Fixme: pp can take an age if you happen to
704 ;; ask for a very large expression. We should
705 ;; probably print it raw once and check it's a
706 ;; sensible size before prettyprinting. -- fx
707 (let ((from (point)))
709 ;; See previous comment for this function.
710 ;; (help-xref-on-pp from (point))
711 (if (< (point) (+ from
20))
712 (delete-region (1- from
) from
))))))
715 ;; If the value is large, move it to the end.
716 (with-current-buffer standard-output
717 (when (> (count-lines (point-min) (point-max)) 10)
718 ;; Note that setting the syntax table like below
719 ;; makes forward-sexp move over a `'s' at the end
721 (set-syntax-table emacs-lisp-mode-syntax-table
)
722 (goto-char val-start-pos
)
723 ;; The line below previously read as
724 ;; (delete-region (point) (progn (end-of-line) (point)))
725 ;; which suppressed display of the buffer local value for
727 (when (looking-at "value is") (replace-match ""))
729 (insert "\n\nValue:")
730 (set (make-local-variable 'help-button-cache
)
732 (insert "value is shown ")
733 (insert-button "below"
734 'action help-button-cache
736 'help-echo
"mouse-2, RET: show value")
740 (let* ((alias (condition-case nil
741 (indirect-variable variable
)
743 (obsolete (get variable
'byte-obsolete-variable
))
745 (safe-var (get variable
'safe-local-variable
))
746 (doc (or (documentation-property variable
'variable-documentation
)
747 (documentation-property alias
'variable-documentation
)))
749 ;; Add a note for variables that have been make-var-buffer-local.
750 (when (and (local-variable-if-set-p variable
)
751 (or (not (local-variable-p variable
))
753 (local-variable-if-set-p variable
))))
755 (princ " Automatically becomes buffer-local when set in any fashion.\n"))
757 ;; Mention if it's an alias
758 (unless (eq alias variable
)
760 (princ (format " This variable is an alias for `%s'.\n" alias
)))
764 (princ " This variable is obsolete")
765 (if (cdr obsolete
) (princ (format " since %s" (cdr obsolete
))))
766 (princ (cond ((stringp use
) (concat ";\n " use
))
767 (use (format ";\n use `%s' instead." (car obsolete
)))
771 (when (member (cons variable val
) file-local-variables-alist
)
773 (if (member (cons variable val
) dir-local-variables-alist
)
774 (let ((file (and (buffer-file-name)
775 (not (file-remote-p (buffer-file-name)))
776 (dir-locals-find-file (buffer-file-name)))))
777 (princ " This variable is a directory local variable")
779 (princ (concat "\n from the file \""
785 (princ " This variable is a file local variable.\n")))
787 (when (memq variable ignored-local-variables
)
789 (princ " This variable is ignored when used as a file local \
792 ;; Can be both risky and safe, eg auto-fill-function.
793 (when (risky-local-variable-p variable
)
795 (princ " This variable is potentially risky when used as a \
796 file local variable.\n")
797 (when (assq variable safe-local-variable-values
)
798 (princ " However, you have added it to \
799 `safe-local-variable-values'.\n")))
803 (princ " This variable is safe as a file local variable ")
804 (princ "if its value\n satisfies the predicate ")
805 (princ (if (byte-code-function-p safe-var
)
806 "which is byte-compiled expression.\n"
807 (format "`%s'.\n" safe-var
))))
809 (if extra-line
(terpri))
810 (princ "Documentation:\n")
811 (with-current-buffer standard-output
812 (insert (or doc
"Not documented as a variable."))))
814 ;; Make a link to customize if this variable can be customized.
815 (when (custom-variable-p variable
)
816 (let ((customize-label "customize"))
819 (princ (concat "You can " customize-label
" this variable."))
820 (with-current-buffer standard-output
823 (concat "\\(" customize-label
"\\)") nil t
)
824 (help-xref-button 1 'help-customize-variable variable
))))
825 ;; Note variable's version or package version
826 (let ((output (describe-variable-custom-version-info variable
)))
832 (with-current-buffer standard-output
833 ;; Return the text we displayed.
834 (buffer-string))))))))
838 (defun describe-syntax (&optional buffer
)
839 "Describe the syntax specifications in the syntax table of BUFFER.
840 The descriptions are inserted in a help buffer, which is then displayed.
841 BUFFER defaults to the current buffer."
843 (setq buffer
(or buffer
(current-buffer)))
844 (help-setup-xref (list #'describe-syntax buffer
)
845 (called-interactively-p 'interactive
))
846 (with-help-window (help-buffer)
847 (let ((table (with-current-buffer buffer
(syntax-table))))
848 (with-current-buffer standard-output
849 (describe-vector table
'internal-describe-syntax-value
)
850 (while (setq table
(char-table-parent table
))
851 (insert "\nThe parent syntax table is:")
852 (describe-vector table
'internal-describe-syntax-value
))))))
854 (defun help-describe-category-set (value)
856 ((null value
) "default")
857 ((char-table-p value
) "deeper char-table ...")
858 (t (condition-case err
859 (category-set-mnemonics value
)
860 (error "invalid"))))))
863 (defun describe-categories (&optional buffer
)
864 "Describe the category specifications in the current category table.
865 The descriptions are inserted in a buffer, which is then displayed.
866 If BUFFER is non-nil, then describe BUFFER's category table instead.
867 BUFFER should be a buffer or a buffer name."
869 (setq buffer
(or buffer
(current-buffer)))
870 (help-setup-xref (list #'describe-categories buffer
)
871 (called-interactively-p 'interactive
))
872 (with-help-window (help-buffer)
873 (let* ((table (with-current-buffer buffer
(category-table)))
874 (docs (char-table-extra-slot table
0)))
875 (if (or (not (vectorp docs
)) (/= (length docs
) 95))
876 (error "Invalid first extra slot in this category table\n"))
877 (with-current-buffer standard-output
878 (insert "Legend of category mnemonics (see the tail for the longer description)\n")
879 (let ((pos (point)) (items 0) lines n
)
881 (if (aref docs i
) (setq items
(1+ items
))))
882 (setq lines
(1+ (/ (1- items
) 4)))
885 (let ((elt (aref docs i
)))
887 (string-match ".*" elt
)
888 (setq elt
(match-string 0 elt
))
889 (if (>= (length elt
) 17)
890 (setq elt
(concat (substring elt
0 14) "...")))
891 (if (< (point) (point-max))
892 (move-to-column (* 20 (/ n lines
)) t
))
893 (insert (+ i ?\s
) ?
: elt
)
894 (if (< (point) (point-max))
898 (if (= (% n lines
) 0)
900 (goto-char (point-max))
902 "character(s)\tcategory mnemonics\n"
903 "------------\t------------------")
904 (describe-vector table
'help-describe-category-set
)
905 (insert "Legend of category mnemonics:\n")
907 (let ((elt (aref docs i
)))
909 (if (string-match "\n" elt
)
910 (setq elt
(substring elt
(match-end 0))))
911 (insert (+ i ?\s
) ": " elt
"\n"))))
912 (while (setq table
(char-table-parent table
))
913 (insert "\nThe parent category table is:")
914 (describe-vector table
'help-describe-category-set
))))))
917 ;;; Replacements for old lib-src/ programs. Don't seem especially useful.
919 ;; Replaces lib-src/digest-doc.c.
921 (defun doc-file-to-man (file)
922 "Produce an nroff buffer containing the doc-strings from the DOC file."
923 (interactive (list (read-file-name "Name of DOC file: " doc-directory
924 internal-doc-file-name t
)))
925 (or (file-readable-p file
)
926 (error "Cannot read file `%s'" file
))
927 (pop-to-buffer (generate-new-buffer "*man-doc*"))
928 (setq buffer-undo-list t
)
929 (insert ".TH \"Command Summary for GNU Emacs\"\n"
930 ".AU Richard M. Stallman\n")
931 (insert-file-contents file
)
933 (while (search-forward "\1f" nil
'move
)
935 (delete-region (1- (point)) (line-end-position))
941 (insert (if (looking-at "F") "Function " "Variable "))
944 (insert ".DS L\n"))))
946 (setq buffer-undo-list nil
)
949 ;; Replaces lib-src/sorted-doc.c.
951 (defun doc-file-to-info (file)
952 "Produce a texinfo buffer with sorted doc-strings from the DOC file."
953 (interactive (list (read-file-name "Name of DOC file: " doc-directory
954 internal-doc-file-name t
)))
955 (or (file-readable-p file
)
956 (error "Cannot read file `%s'" file
))
957 (let ((i 0) type name doc alist
)
959 (insert-file-contents file
)
960 ;; The characters "@{}" need special treatment.
961 (while (re-search-forward "[@{}]" nil t
)
965 (goto-char (point-min))
966 (while (search-forward "\1f" nil t
)
967 (unless (looking-at "S")
968 (setq type
(char-after)
969 name
(buffer-substring (1+ (point)) (line-end-position))
970 doc
(buffer-substring (line-beginning-position 2)
971 (if (search-forward "\1f" nil
'move
)
974 alist
(cons (list name type doc
) alist
))
976 (pop-to-buffer (generate-new-buffer "*info-doc*"))
977 (setq buffer-undo-list t
)
978 ;; Write the output header.
979 (insert "\\input texinfo @c -*-texinfo-*-\n"
980 "@setfilename emacsdoc.info\n"
981 "@settitle Command Summary for GNU Emacs\n"
984 "@unnumbered Command Summary for GNU Emacs\n\n"
987 "@global@let@ITEM@item\n"
988 "@def@item{@filbreak@vskip5pt@ITEM}\n"
989 "@font@tensy cmsy10 scaled @magstephalf\n"
990 "@font@teni cmmi10 scaled @magstephalf\n"
991 "@def\\{{@tensy@char110}}\n" ; this backslash goes with cmr10
992 "@def|{{@tensy@char106}}\n"
993 "@def@{{{@tensy@char102}}\n"
994 "@def@}{{@tensy@char103}}\n"
995 "@def<{{@teni@char62}}\n"
996 "@def>{{@teni@char60}}\n"
999 "@tableindent-0.2in\n"
1001 ;; Sort the array by name; within each name, by type (functions first).
1002 (setq alist
(sort alist
(lambda (e1 e2
)
1003 (if (string-equal (car e1
) (car e2
))
1004 (<= (cadr e1
) (cadr e2
))
1005 (string-lessp (car e1
) (car e2
))))))
1006 ;; Print each function.
1009 (if (char-equal (cadr e
) ?\F
) "Function" "Variable")
1010 " @code{" (car e
) "}\n@display\n"
1013 ;; Try to avoid a save size overflow in the TeX output routine.
1014 (if (zerop (setq i
(%
(1+ i
) 100)))
1015 (insert "\n@end table\n@table @asis\n")))
1016 (insert "@end table\n"
1018 (setq buffer-undo-list nil
)
1023 ;;; help-fns.el ends here