;;; help-mode.el --- `help-mode' used by *Help* buffers
-;; Copyright (C) 1985, 1986, 1993, 1994, 1998, 1999, 2000, 2001
-;; Free Software Foundation, Inc.
+;; Copyright (C) 1985, 1986, 1993, 1994, 1998, 1999, 2000, 2001, 2002,
+;; 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
;; Maintainer: FSF
;; Keywords: help, internal
;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING. If not, write to the
-;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-;; Boston, MA 02111-1307, USA.
+;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+;; Boston, MA 02110-1301, USA.
;;; Commentary:
;;; Code:
(require 'button)
-(eval-when-compile (require 'view))
+(require 'view)
(defvar help-mode-map (make-sparse-keymap)
"Keymap for help mode.")
(define-key help-mode-map [mouse-2] 'help-follow-mouse)
(define-key help-mode-map "\C-c\C-b" 'help-go-back)
-(define-key help-mode-map "\C-c\C-c" 'help-follow)
+(define-key help-mode-map "\C-c\C-c" 'help-follow-symbol)
;; Documentation only, since we use minor-mode-overriding-map-alist.
(define-key help-mode-map "\r" 'help-follow)
(setq-default help-xref-stack nil help-xref-stack-item nil)
-
+(defcustom help-mode-hook nil
+ "Hook run by `help-mode'."
+ :type 'hook
+ :group 'help)
\f
;; Button types used by help
-;; Make some button types that all use the same naming conventions
-(dolist (help-type '("function" "variable" "face"
- "coding-system" "input-method" "character-set"))
- (define-button-type (intern (purecopy (concat "help-" help-type)))
- 'help-function (intern (concat "describe-" help-type))
- 'help-echo (purecopy (concat "mouse-2, RET: describe this " help-type))
- 'action #'help-button-action))
+(define-button-type 'help-xref
+ 'follow-link t
+ 'action #'help-button-action)
+
+(defun help-button-action (button)
+ "Call BUTTON's help function."
+ (help-do-xref (button-start button)
+ (button-get button 'help-function)
+ (button-get button 'help-args)))
+
+;; These 6 calls to define-button-type were generated in a dolist
+;; loop, but that is bad because it means these button types don't
+;; have an easily found definition.
+
+(define-button-type 'help-function
+ :supertype 'help-xref
+ 'help-function 'describe-function
+ 'help-echo (purecopy "mouse-2, RET: describe this function"))
+
+(define-button-type 'help-variable
+ :supertype 'help-xref
+ 'help-function 'describe-variable
+ 'help-echo (purecopy "mouse-2, RET: describe this variable"))
+
+(define-button-type 'help-face
+ :supertype 'help-xref
+ 'help-function 'describe-face
+ 'help-echo (purecopy "mouse-2, RET: describe this face"))
+
+(define-button-type 'help-coding-system
+ :supertype 'help-xref
+ 'help-function 'describe-coding-system
+ 'help-echo (purecopy "mouse-2, RET: describe this coding system"))
+
+(define-button-type 'help-input-method
+ :supertype 'help-xref
+ 'help-function 'describe-input-method
+ 'help-echo (purecopy "mouse-2, RET: describe this input method"))
+
+(define-button-type 'help-character-set
+ :supertype 'help-xref
+ 'help-function 'describe-character-set
+ 'help-echo (purecopy "mouse-2, RET: describe this character set"))
;; make some more ideosyncratic button types
(define-button-type 'help-symbol
+ :supertype 'help-xref
'help-function #'help-xref-interned
- 'help-echo (purecopy "mouse-2, RET: describe this symbol")
- 'action #'help-button-action)
+ 'help-echo (purecopy "mouse-2, RET: describe this symbol"))
(define-button-type 'help-back
+ :supertype 'help-xref
'help-function #'help-xref-go-back
- 'help-echo (purecopy "mouse-2, RET: go back to previous help buffer")
- 'action #'help-button-action)
+ 'help-echo (purecopy "mouse-2, RET: go back to previous help buffer"))
(define-button-type 'help-info
+ :supertype 'help-xref
'help-function #'info
- 'help-echo (purecopy"mouse-2, RET: read this Info node")
- 'action #'help-button-action)
+ 'help-echo (purecopy "mouse-2, RET: read this Info node"))
+
+(define-button-type 'help-url
+ :supertype 'help-xref
+ 'help-function #'browse-url
+ 'help-echo (purecopy "mouse-2, RET: view this URL in a browser"))
(define-button-type 'help-customize-variable
+ :supertype 'help-xref
'help-function (lambda (v)
- (if help-xref-stack
- (pop help-xref-stack))
(customize-variable v))
- 'help-echo (purecopy "mouse-2, RET: customize variable")
- 'action #'help-button-action)
+ 'help-echo (purecopy "mouse-2, RET: customize variable"))
(define-button-type 'help-customize-face
+ :supertype 'help-xref
'help-function (lambda (v)
- (if help-xref-stack
- (pop help-xref-stack))
(customize-face v))
- 'help-echo (purecopy "mouse-2, RET: customize face")
- 'action #'help-button-action)
+ 'help-echo (purecopy "mouse-2, RET: customize face"))
(define-button-type 'help-function-def
+ :supertype 'help-xref
'help-function (lambda (fun file)
(require 'find-func)
- ;; Don't use find-function-noselect because it follows
+ (when (eq file 'C-source)
+ (setq file
+ (help-C-file-name (indirect-function fun) 'fun)))
+ ;; Don't use find-function-noselect because it follows
;; aliases (which fails for built-in functions).
- (let* ((location (find-function-search-for-symbol
- fun nil file)))
+ (let ((location
+ (find-function-search-for-symbol fun nil file)))
(pop-to-buffer (car location))
(goto-char (cdr location))))
- 'help-echo (purecopy "mouse-2, RET: find function's definition")
- 'action #'help-button-action)
+ 'help-echo (purecopy "mouse-2, RET: find function's definition"))
(define-button-type 'help-variable-def
+ :supertype 'help-xref
'help-function (lambda (var &optional file)
- (let ((location
- (find-variable-noselect var file)))
+ (when (eq file 'C-source)
+ (setq file (help-C-file-name var 'var)))
+ (let ((location (find-variable-noselect var file)))
(pop-to-buffer (car location))
(goto-char (cdr location))))
- 'help-echo (purecopy"mouse-2, RET: find variable's definition")
- 'action #'help-button-action)
+ 'help-echo (purecopy"mouse-2, RET: find variable's definition"))
-(defun help-button-action (button)
- "Call BUTTON's help function."
- (help-do-xref (button-start button)
- (button-get button 'help-function)
- (button-get button 'help-args)))
+(define-button-type 'help-face-def
+ :supertype 'help-xref
+ 'help-function (lambda (fun file)
+ (require 'find-func)
+ ;; Don't use find-function-noselect because it follows
+ ;; aliases (which fails for built-in functions).
+ (let ((location
+ (find-function-search-for-symbol fun 'defface file)))
+ (pop-to-buffer (car location))
+ (goto-char (cdr location))))
+ 'help-echo (purecopy "mouse-2, RET: find face's definition"))
\f
;;;###autoload
-(define-derived-mode help-mode nil "Help"
+(defun help-mode ()
"Major mode for viewing help text and navigating references in it.
Entry to this mode runs the normal hook `help-mode-hook'.
Commands:
\\{help-mode-map}"
- (setq font-lock-defaults nil) ; font-lock would defeat xref
+ (interactive)
+ (kill-all-local-variables)
+ (use-local-map help-mode-map)
+ (setq mode-name "Help")
+ (setq major-mode 'help-mode)
(view-mode)
(make-local-variable 'view-no-disable-on-exit)
- (setq view-no-disable-on-exit t))
+ (setq view-no-disable-on-exit t)
+ (setq view-exit-action (lambda (buffer)
+ (or (window-minibuffer-p (selected-window))
+ (one-window-p t)
+ (delete-window))))
+ (run-mode-hooks 'help-mode-hook))
;;;###autoload
(defun help-mode-setup ()
;;;###autoload
(defun help-mode-finish ()
+ (let ((entry (assq (selected-window) view-return-to-alist)))
+ (if entry
+ ;; When entering Help mode from the Help window,
+ ;; such as by following a link, preserve the same
+ ;; meaning for the q command.
+ ;; (setcdr entry (cons (selected-window) help-return-method))
+ nil
+ (setq view-return-to-alist
+ (cons (cons (selected-window) help-return-method)
+ view-return-to-alist))))
(when (eq major-mode 'help-mode)
;; View mode's read-only status of existing *Help* buffer is lost
;; by with-output-to-temp-buffer.
(toggle-read-only 1)
- (help-make-xrefs (current-buffer)))
- (setq view-return-to-alist
- (list (cons (selected-window) help-return-method))))
-
+ (help-make-xrefs (current-buffer))))
\f
-;;; Grokking cross-reference information in doc strings and
-;;; hyperlinking it.
+;; Grokking cross-reference information in doc strings and
+;; hyperlinking it.
;; This may have some scope for extension and the same or something
;; similar should be done for widget doc strings, which currently use
;; another mechanism.
-(defcustom help-highlight-p t
- "*If non-nil, `help-make-xrefs' highlight cross-references.
-Under a window system it highlights them with face defined by
-`help-highlight-face'."
- :group 'help
- :version "20.3"
- :type 'boolean)
-
-(defcustom help-highlight-face 'underline
- "Face used by `help-make-xrefs' to highlight cross-references.
-Must be previously-defined."
- :group 'help
- :version "20.3"
- :type 'face)
-
(defvar help-back-label (purecopy "[back]")
"Label to use by `help-make-xrefs' for the go-back reference.")
(defconst help-xref-symbol-regexp
- (purecopy (concat "\\(\\<\\(\\(variable\\|option\\)\\|"
- "\\(function\\|command\\)\\|"
- "\\(face\\)\\|"
- "\\(symbol\\)\\|"
- "\\(source \\(?:code \\)?\\(?:of\\|for\\)\\)\\)\\s-+\\)?"
+ (purecopy (concat "\\(\\<\\(\\(variable\\|option\\)\\|" ; Link to var
+ "\\(function\\|command\\)\\|" ; Link to function
+ "\\(face\\)\\|" ; Link to face
+ "\\(symbol\\|program\\)\\|" ; Don't link
+ "\\(source \\(?:code \\)?\\(?:of\\|for\\)\\)\\)"
+ "[ \t\n]+\\)?"
;; Note starting with word-syntax character:
"`\\(\\sw\\(\\sw\\|\\s_\\)+\\)'"))
"Regexp matching doc string references to symbols.
The words preceding the quoted symbol can be used in doc strings to
distinguish references to variables, functions and symbols.")
-(defconst help-xref-mule-regexp nil
+(defvar help-xref-mule-regexp nil
"Regexp matching doc string references to MULE-related keywords.
It is usually nil, and is temporarily bound to an appropriate regexp
(defconst help-xref-info-regexp
- (purecopy "\\<[Ii]nfo[ \t\n]+node[ \t\n]+`\\([^']+\\)'")
+ (purecopy "\\<[Ii]nfo[ \t\n]+\\(node\\|anchor\\)[ \t\n]+`\\([^']+\\)'")
"Regexp matching doc string references to an Info node.")
+(defconst help-xref-url-regexp
+ (purecopy "\\<[Uu][Rr][Ll][ \t\n]+`\\([^']+\\)'")
+ "Regexp matching doc string references to a URL.")
+
;;;###autoload
(defun help-setup-xref (item interactive-p)
"Invoked from commands using the \"*Help*\" buffer to install some xref info.
because we want to record the \"previous\" position of point so we can
restore it properly when going back."
(with-current-buffer (help-buffer)
- (if interactive-p
- ;; Why do we want to prevent the user from going back ?? -stef
- (setq help-xref-stack nil)
- (when help-xref-stack-item
- (push (cons (point) help-xref-stack-item) help-xref-stack)))
+ (when help-xref-stack-item
+ (push (cons (point) help-xref-stack-item) help-xref-stack))
+ (when interactive-p
+ (let ((tail (nthcdr 10 help-xref-stack)))
+ ;; Truncate the stack.
+ (if tail (setcdr tail nil))))
(setq help-xref-stack-item item)))
(defvar help-xref-following nil
(current-buffer)
(get-buffer-create "*Help*"))))
+(defvar help-xref-override-view-map
+ (let ((map (make-sparse-keymap)))
+ (set-keymap-parent map view-mode-map)
+ (define-key map "\r" nil)
+ map)
+ "Replacement keymap for `view-mode' in help buffers.")
+
;;;###autoload
(defun help-make-xrefs (&optional buffer)
"Parse and hyperlink documentation cross-references in the given BUFFER.
-Find cross-reference information in a buffer and, if
-`help-highlight-p' is non-nil, highlight it with face defined by
-`help-highlight-face'; activate such cross references for selection
-with `help-follow'. Cross-references have the canonical form `...'
-and the type of reference may be disambiguated by the preceding
-word(s) used in `help-xref-symbol-regexp'.
+Find cross-reference information in a buffer and activate such cross
+references for selection with `help-follow'. Cross-references have
+the canonical form `...' and the type of reference may be
+disambiguated by the preceding word(s) used in
+`help-xref-symbol-regexp'. Faces only get cross-referenced if
+preceded or followed by the word `face'. Variables without
+variable documentation do not get cross-referenced, unless
+preceded by the word `variable' or `option'.
If the variable `help-xref-mule-regexp' is non-nil, find also
cross-reference information related to multilingual environment
;; Info references
(save-excursion
(while (re-search-forward help-xref-info-regexp nil t)
- (let ((data (match-string 1)))
+ (let ((data (match-string 2)))
(save-match-data
(unless (string-match "^([^)]+)" data)
(setq data (concat "(emacs)" data))))
- (help-xref-button 1 'help-info data))))
+ (help-xref-button 2 'help-info data))))
+ ;; URLs
+ (save-excursion
+ (while (re-search-forward help-xref-url-regexp nil t)
+ (let ((data (match-string 1)))
+ (help-xref-button 1 'help-url data))))
;; Mule related keywords. Do this before trying
;; `help-xref-symbol-regexp' because some of Mule
;; keywords have variable or function definitions.
(sym (intern-soft data)))
(if sym
(cond
- ((match-string 3) ; `variable' &c
- (and (boundp sym) ; `variable' doesn't ensure
+ ((match-string 3) ; `variable' &c
+ (and (or (boundp sym) ; `variable' doesn't ensure
; it's actually bound
+ (get sym 'variable-documentation))
(help-xref-button 8 'help-variable sym)))
- ((match-string 4) ; `function' &c
+ ((match-string 4) ; `function' &c
(and (fboundp sym) ; similarly
(help-xref-button 8 'help-function sym)))
((match-string 5) ; `face'
(help-xref-button 8 'help-face sym)))
((match-string 6)) ; nothing for `symbol'
((match-string 7)
-;; this used:
-;; #'(lambda (arg)
-;; (let ((location
-;; (find-function-noselect arg)))
-;; (pop-to-buffer (car location))
-;; (goto-char (cdr location))))
+;;; this used:
+;;; #'(lambda (arg)
+;;; (let ((location
+;;; (find-function-noselect arg)))
+;;; (pop-to-buffer (car location))
+;;; (goto-char (cdr location))))
(help-xref-button 8 'help-function-def sym))
- ((and (boundp sym) (fboundp sym))
+ ((and
+ (facep sym)
+ (save-match-data (looking-at "[ \t\n]+face\\W")))
+ (help-xref-button 8 'help-face sym))
+ ((and (or (boundp sym)
+ (get sym 'variable-documentation))
+ (fboundp sym))
;; We can't intuit whether to use the
;; variable or function doc -- supply both.
(help-xref-button 8 'help-symbol sym))
- ((boundp sym)
+ ((and
+ (or (boundp sym)
+ (get sym 'variable-documentation))
+ (or
+ (documentation-property
+ sym 'variable-documentation)
+ (condition-case nil
+ (documentation-property
+ (indirect-variable sym)
+ 'variable-documentation)
+ (cyclic-variable-indirection nil))))
(help-xref-button 8 'help-variable sym))
((fboundp sym)
- (help-xref-button 8 'help-function sym))
- ((facep sym)
- (help-xref-button 8 'help-face sym)))))))
+ (help-xref-button 8 'help-function sym)))))))
;; An obvious case of a key substitution:
(save-excursion
(while (re-search-forward
(goto-char (point-min))
;; Find a header and the column at which the command
;; name will be found.
+
+ ;; If the keymap substitution isn't the last thing in
+ ;; the doc string, and if there is anything on the
+ ;; same line after it, this code won't recognize the end of it.
(while (re-search-forward "^key +binding\n\\(-+ +\\)-+\n\n"
nil t)
(let ((col (- (match-end 1) (match-beginning 1))))
(while
- ;; Ignore single blank lines in table, but not
- ;; double ones, which should terminate it.
- (and (not (looking-at "\n\\s-*\n"))
- (progn
- (and (eolp) (forward-line))
- (end-of-line)
- (skip-chars-backward "^\t\n")
- (if (and (>= (current-column) col)
- (looking-at "\\(\\sw\\|-\\)+$"))
- (let ((sym (intern-soft (match-string 0))))
- (if (fboundp sym)
- (help-xref-button 0 'help-function sym))))
- (zerop (forward-line)))))))))
- (set-syntax-table stab))
+ (and (not (eobp))
+ ;; Stop at a pair of blank lines.
+ (not (looking-at "\n\\s-*\n")))
+ ;; Skip a single blank line.
+ (and (eolp) (forward-line))
+ (end-of-line)
+ (skip-chars-backward "^\t\n")
+ (if (and (>= (current-column) col)
+ (looking-at "\\(\\sw\\|-\\)+$"))
+ (let ((sym (intern-soft (match-string 0))))
+ (if (fboundp sym)
+ (help-xref-button 0 'help-function sym))))
+ (forward-line))))))
+ (set-syntax-table stab))
;; Delete extraneous newlines at the end of the docstring
(goto-char (point-max))
(while (and (not (bobp)) (bolp))
(delete-char -1))
+ (insert "\n")
;; Make a back-reference in this buffer if appropriate.
(when help-xref-stack
- (insert "\n\n")
+ (insert "\n")
(help-insert-xref-button help-back-label 'help-back
- (current-buffer))))
+ (current-buffer))
+ (insert "\n")))
;; View mode steals RET from us.
(set (make-local-variable 'minor-mode-overriding-map-alist)
- (list (cons 'view-mode
- (let ((map (make-sparse-keymap)))
- (set-keymap-parent map view-mode-map)
- (define-key map "\r" 'help-follow)
- map))))
+ (list (cons 'view-mode help-xref-override-view-map)))
(set-buffer-modified-p old-modified))))
;;;###autoload
;;;###autoload
(defun help-xref-on-pp (from to)
"Add xrefs for symbols in `pp's output between FROM and TO."
- (let ((ost (syntax-table)))
- (unwind-protect
- (save-excursion
- (save-restriction
- (set-syntax-table emacs-lisp-mode-syntax-table)
- (narrow-to-region from to)
- (goto-char (point-min))
- (while (not (eobp))
- (cond
- ((looking-at "\"") (forward-sexp 1))
- ((looking-at "#<") (search-forward ">" nil 'move))
- ((looking-at "\\(\\(\\sw\\|\\s_\\)+\\)")
- (let* ((sym (intern-soft (match-string 1)))
- (type (cond ((fboundp sym) 'help-function)
- ((or (memq sym '(t nil))
- (keywordp sym))
- nil)
- ((and sym (boundp sym))
- 'help-variable))))
- (when type (help-xref-button 1 type sym)))
- (goto-char (match-end 1)))
- (t (forward-char 1))))))
- (set-syntax-table ost))))
+ (if (> (- to from) 5000) nil
+ (with-syntax-table emacs-lisp-mode-syntax-table
+ (save-excursion
+ (save-restriction
+ (narrow-to-region from to)
+ (goto-char (point-min))
+ (condition-case nil
+ (while (not (eobp))
+ (cond
+ ((looking-at "\"") (forward-sexp 1))
+ ((looking-at "#<") (search-forward ">" nil 'move))
+ ((looking-at "\\(\\(\\sw\\|\\s_\\)+\\)")
+ (let* ((sym (intern-soft (match-string 1)))
+ (type (cond ((fboundp sym) 'help-function)
+ ((or (memq sym '(t nil))
+ (keywordp sym))
+ nil)
+ ((and sym
+ (or (boundp sym)
+ (get sym
+ 'variable-documentation)))
+ 'help-variable))))
+ (when type (help-xref-button 1 type sym)))
+ (goto-char (match-end 1)))
+ (t (forward-char 1))))
+ (error nil)))))))
\f
;; Additional functions for (re-)creating types of help buffers.
;; Don't record the current entry in the stack.
(setq help-xref-stack-item nil)
(describe-function symbol)))
- (sdoc (when (boundp symbol)
+ (sdoc (when (or (boundp symbol)
+ (get symbol 'variable-documentation))
;; Don't record the current entry in the stack.
(setq help-xref-stack-item nil)
(describe-variable symbol))))
(sdoc
;; We now have a help buffer on the variable.
;; Insert the function and face text before it.
- (when (or fdoc facedoc)
+ (when (or fdoc facedoc)
(goto-char (point-min))
(let ((inhibit-read-only t))
(when fdoc
(insert fdoc "\n\n")
- (when facedoc
- (insert (make-string 30 ?-) "\n\n" (symbol-name symbol)
+ (when facedoc
+ (insert (make-string 30 ?-) "\n\n" (symbol-name symbol)
" is also a " "face." "\n\n")))
(when facedoc
(insert facedoc "\n\n"))
(help-setup-xref (list #'help-xref-interned symbol) nil)))))))
\f
-;;; Navigation/hyperlinking with xrefs
-
-(defun help-follow-mouse (click)
- "Follow the cross-reference that you CLICK on."
- (interactive "e")
- (let* ((start (event-start click))
- (window (car start))
- (pos (car (cdr start))))
- (with-current-buffer (window-buffer window)
- (help-follow pos))))
+;; Navigation/hyperlinking with xrefs
(defun help-xref-go-back (buffer)
"From BUFFER, go back to previous help buffer text using `help-xref-stack'."
method (cadr item)
args (cddr item))))
(apply method args)
- ;; FIXME: are we sure we're in the right buffer ?
- (goto-char position)))
+ (with-current-buffer buffer
+ (if (get-buffer-window buffer)
+ (set-window-point (get-buffer-window buffer) position)
+ (goto-char position)))))
(defun help-go-back ()
- "Invoke the [back] button (if any) in the Help mode buffer."
+ "Go back to previous topic in this help buffer."
(interactive)
- (let ((back-button (button-at (1- (point-max)))))
- (if back-button
- (button-activate back-button)
- (error "No [back] button"))))
+ (if help-xref-stack
+ (help-xref-go-back (current-buffer))
+ (error "No previous help buffer")))
(defun help-do-xref (pos function args)
"Call the help cross-reference function FUNCTION with args ARGS.
(let ((help-xref-following t))
(apply function args)))
-(defun help-follow (&optional pos)
- "Follow cross-reference at POS, defaulting to point.
+;; The doc string is meant to explain what buttons do.
+(defun help-follow-mouse ()
+ "Follow the cross-reference that you click on."
+ (interactive)
+ (error "No cross-reference here"))
+
+;; The doc string is meant to explain what buttons do.
+(defun help-follow ()
+ "Follow cross-reference at point.
For the cross-reference format, see `help-make-xrefs'."
+ (interactive)
+ (error "No cross-reference here"))
+
+(defun help-follow-symbol (&optional pos)
+ "In help buffer, show docs for symbol at POS, defaulting to point.
+Show all docs for that symbol as either a variable, function or face."
(interactive "d")
(unless pos
(setq pos (point)))
- (unless (push-button pos)
- ;; check if the symbol under point is a function or variable
- (let ((sym
- (intern
- (save-excursion
- (goto-char pos) (skip-syntax-backward "w_")
- (buffer-substring (point)
- (progn (skip-syntax-forward "w_")
- (point)))))))
- (when (or (boundp sym) (fboundp sym) (facep sym))
- (help-do-xref pos #'help-xref-interned (list sym))))))
-
+ ;; check if the symbol under point is a function, variable or face
+ (let ((sym
+ (intern
+ (save-excursion
+ (goto-char pos) (skip-syntax-backward "w_")
+ (buffer-substring (point)
+ (progn (skip-syntax-forward "w_")
+ (point)))))))
+ (when (or (boundp sym)
+ (get sym 'variable-documentation)
+ (fboundp sym) (facep sym))
+ (help-do-xref pos #'help-xref-interned (list sym)))))
+
+(defun help-insert-string (string)
+ "Insert STRING to the help buffer and install xref info for it.
+This function can be used to restore the old contents of the help buffer
+when going back to the previous topic in the xref stack. It is needed
+in case when it is impossible to recompute the old contents of the
+help buffer by other means."
+ (setq help-xref-stack-item (list #'help-insert-string string))
+ (with-output-to-temp-buffer (help-buffer)
+ (insert string)))
(provide 'help-mode)
+;; arch-tag: 850954ae-3725-4cb4-8e91-0bf6d52d6b0b
;;; help-mode.el ends here
-
-