;;; help.el --- help commands for Emacs
-;; Copyright (C) 1985, 1986, 1993, 1994 Free Software Foundation, Inc.
+;; Copyright (C) 1985, 1986, 1993, 1994, 1998 Free Software Foundation, Inc.
;; Maintainer: FSF
;; Keywords: help, internal
;; GNU General Public License for more details.
;; 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, 675 Mass Ave, Cambridge, MA 02139, USA.
+;; 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.
;;; Commentary:
-;; This code implements GNU Emac's on-line help system, the one invoked by
+;; This code implements GNU Emacs' on-line help system, the one invoked by
;;`M-x help-for-help'.
;;; Code:
"Keymap for help mode.")
(define-key global-map (char-to-string help-char) 'help-command)
+(define-key global-map [help] 'help-command)
+(define-key global-map [f1] 'help-command)
(fset 'help-command help-map)
(define-key help-map (char-to-string help-char) 'help-for-help)
+(define-key help-map [help] 'help-for-help)
+(define-key help-map [f1] 'help-for-help)
(define-key help-map "?" 'help-for-help)
(define-key help-map "\C-c" 'describe-copying)
(define-key help-map "\C-d" 'describe-distribution)
(define-key help-map "\C-w" 'describe-no-warranty)
(define-key help-map "\C-p" 'describe-project)
-(define-key help-map "a" 'command-apropos)
+(define-key help-map "a" 'apropos-command)
(define-key help-map "b" 'describe-bindings)
(define-key help-map "i" 'info)
(define-key help-map "\C-f" 'Info-goto-emacs-command-node)
(define-key help-map "\C-k" 'Info-goto-emacs-key-command-node)
+(define-key help-map "\C-i" 'info-lookup-symbol)
(define-key help-map "l" 'view-lossage)
(define-key help-map "q" 'help-quit)
+(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 "\t" 'help-next-ref)
+(define-key help-mode-map [backtab] 'help-previous-ref)
+(define-key help-mode-map [(shift tab)] 'help-previous-ref)
+;; Documentation only, since we use minor-mode-overriding-map-alist.
+(define-key help-mode-map "\r" 'help-follow)
+
+;; Font-locking is incompatible with the new xref stuff.
+;(defvar help-font-lock-keywords
+; (eval-when-compile
+; (let ((name-char "[-+a-zA-Z0-9_*]") (sym-char "[-+a-zA-Z0-9_:*]"))
+; (list
+; ;;
+; ;; The symbol itself.
+; (list (concat "\\`\\(" name-char "+\\)\\(\\(:\\)\\|\\('\\)\\)")
+; '(1 (if (match-beginning 3)
+; font-lock-function-name-face
+; font-lock-variable-name-face)))
+; ;;
+; ;; Words inside `' which tend to be symbol names.
+; (list (concat "`\\(" sym-char sym-char "+\\)'")
+; 1 'font-lock-constant-face t)
+; ;;
+; ;; CLisp `:' keywords as references.
+; (list (concat "\\<:" sym-char "+\\>") 0 'font-lock-builtin-face t))))
+; "Default expressions to highlight in Help mode.")
+
+(defvar help-xref-stack nil
+ "A stack of ways by which to return to help buffers after following xrefs.
+Used by `help-follow' and `help-xref-go-back'.
+An element looks like (POSITION FUNCTION ARGS...).
+To use the element, do (apply FUNCTION ARGS) then (goto-char POSITION).")
+(put 'help-xref-stack 'permanent-local t)
+
+(defvar help-xref-stack-item nil
+ "An item for `help-follow' in this buffer to push onto `help-xref-stack'.
+The format is (FUNCTION ARGS...).")
+(put 'help-xref-stack-item 'permanent-local t)
+
+(setq-default help-xref-stack nil help-xref-stack-item nil)
+
(defun help-mode ()
- "Major mode for viewing help text.
+ "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}"
(use-local-map help-mode-map)
(setq mode-name "Help")
(setq major-mode 'help-mode)
+ (make-local-variable 'font-lock-defaults)
+ (setq font-lock-defaults nil) ; font-lock would defeat xref
+ (view-mode)
+ (make-local-variable 'view-no-disable-on-exit)
+ (setq view-no-disable-on-exit t)
+ ;; `help-make-xrefs' would be run here if not invoked from
+ ;; `help-mode-maybe'.
(run-hooks 'help-mode-hook))
+(defun help-mode-maybe ()
+ (if (eq major-mode 'fundamental-mode)
+ (help-mode))
+ (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))))
+
+(add-hook 'temp-buffer-show-hook 'help-mode-maybe)
+
(defun help-quit ()
(interactive)
nil)
-(defun help-with-tutorial ()
- "Select the Emacs learn-by-doing tutorial."
- (interactive)
- (let ((file (expand-file-name "~/TUTORIAL")))
+(defun help-with-tutorial (&optional arg)
+ "Select the Emacs learn-by-doing tutorial.
+If there is a tutorial version written in the language
+of the selected language environment, that version is used.
+If there's no tutorial in that language, `TUTORIAL' is selected.
+With arg, you are asked to choose which language."
+ (interactive "P")
+ (let ((lang (if arg
+ (read-language-name 'tutorial "Language: " "English")
+ (if (get-language-info current-language-environment 'tutorial)
+ current-language-environment
+ "English")))
+ file filename)
+ (setq filename (get-language-info lang 'tutorial))
+ (setq file (expand-file-name (concat "~/" filename)))
(delete-other-windows)
(if (get-file-buffer file)
(switch-to-buffer (get-file-buffer file))
(setq buffer-file-name file)
(setq default-directory (expand-file-name "~/"))
(setq buffer-auto-save-file-name nil)
- (insert-file-contents (expand-file-name "TUTORIAL" data-directory))
+ (insert-file-contents (expand-file-name filename data-directory))
(goto-char (point-min))
(search-forward "\n<<")
(beginning-of-line)
(goto-char (point-min))
(set-buffer-modified-p nil))))
-(defun describe-key-briefly (key)
- "Print the name of the function KEY invokes. KEY is a string."
- (interactive "kDescribe key briefly: ")
+(defun describe-key-briefly (key &optional insert)
+ "Print the name of the function KEY invokes. KEY is a string.
+If INSERT (the prefix arg) is non-nil, insert the message in the buffer."
+ (interactive "kDescribe key briefly: \nP")
;; If this key seq ends with a down event, discard the
;; following click or drag event. Otherwise that would
;; erase the message.
(and (symbolp type)
(memq 'down (event-modifiers type))
(read-event)))
- (let ((defn (key-binding key)))
- (if (or (null defn) (integerp defn))
- (message "%s is undefined" (key-description key))
- (message "%s runs the command %s"
- (key-description key)
- (if (symbolp defn) defn (prin1-to-string defn))))))
+ (save-excursion
+ (let ((modifiers (event-modifiers (aref key 0)))
+ (standard-output (if insert (current-buffer) t))
+ window position)
+ ;; For a mouse button event, go to the button it applies to
+ ;; to get the right key bindings. And go to the right place
+ ;; in case the keymap depends on where you clicked.
+ (if (or (memq 'click modifiers) (memq 'down modifiers)
+ (memq 'drag modifiers))
+ (setq window (posn-window (event-start (aref key 0)))
+ position (posn-point (event-start (aref key 0)))))
+ (if (windowp window)
+ (progn
+ (set-buffer (window-buffer window))
+ (goto-char position)))
+ ;; Ok, now look up the key and name the command.
+ (let ((defn (key-binding key))
+ (key-desc (key-description key)))
+ (if (or (null defn) (integerp defn))
+ (princ (format "%s is undefined" key-desc))
+ (princ (format (if insert
+ "`%s' (`%s')"
+ (if (windowp window)
+ "%s at that spot runs the command %s"
+ "%s runs the command %s"))
+ key-desc
+ (if (symbolp defn) defn (prin1-to-string defn)))))))))
+
+(defvar help-return-method nil
+ "What to do to \"exit\" the help buffer.
+This is a list
+ (WINDOW . t) delete the selected window, go to WINDOW.
+ (WINDOW . quit-window) do quit-window, then select WINDOW.
+ (WINDOW BUF START POINT) display BUF at START, POINT, then select WINDOW.")
(defun print-help-return-message (&optional function)
"Display or return message saying how to restore windows after help command.
If FUNCTION is nil, applies `message' to it, thus printing it."
(and (not (get-buffer-window standard-output))
(let ((first-message
- (cond ((or (member (buffer-name standard-output)
- special-display-buffer-names)
- (assoc (buffer-name standard-output)
- special-display-buffer-names)
- (let (found
- (tail special-display-regexps)
- (name (buffer-name standard-output)))
- (while (and tail (not found))
- (if (or (and (consp (car tail))
- (string-match (car (car tail)) name))
- (and (stringp (car tail))
- (string-match (car tail) name)))
- (setq found t))
- (setq tail (cdr tail)))
- found))
+ (cond ((special-display-p (buffer-name standard-output))
+ (setq help-return-method (cons (selected-window) t))
;; If the help output buffer is a special display buffer,
;; don't say anything about how to get rid of it.
;; First of all, the user will do that with the window
;; manager, not with Emacs.
;; Secondly, the buffer has not been displayed yet,
;; so we don't know whether its frame will be selected.
- ;; Even the message about scrolling the help
- ;; might be wrong, but it seems worth showing it anyway.
nil)
((not (one-window-p t))
+ (setq help-return-method
+ (cons (selected-window) 'quit-window))
"Type \\[switch-to-buffer-other-window] RET to restore the other window.")
(pop-up-windows
+ (setq help-return-method (cons (selected-window) t))
"Type \\[delete-other-windows] to remove help window.")
(t
+ (setq help-return-method
+ (list (selected-window) (window-buffer)
+ (window-start) (window-point)))
"Type \\[switch-to-buffer] RET to remove help window."))))
(funcall (or function 'message)
(concat
(substitute-command-keys first-message)
"")
(if first-message " " "")
- (substitute-command-keys
- "\\[scroll-other-window] to scroll the help."))))))
+ ;; If the help buffer will go in a separate frame,
+ ;; it's no use mentioning a command to scroll, so don't.
+ (if (special-display-p (buffer-name standard-output))
+ nil
+ (if (same-window-p (buffer-name standard-output))
+ ;; Say how to scroll this window.
+ (substitute-command-keys
+ "\\[scroll-up] to scroll the help.")
+ ;; Say how to scroll some other window.
+ (substitute-command-keys
+ "\\[scroll-other-window] to scroll the help."))))))))
(defun describe-key (key)
"Display documentation of the function invoked by KEY. KEY is a string."
(and (symbolp type)
(memq 'down (event-modifiers type))
(read-event)))
- (let ((defn (key-binding key)))
- (if (or (null defn) (integerp defn))
- (message "%s is undefined" (key-description key))
- (with-output-to-temp-buffer "*Help*"
- (prin1 defn)
- (princ ":\n")
- (if (documentation defn)
- (princ (documentation defn))
- (princ "not documented"))
- (save-excursion
- (set-buffer standard-output)
- (help-mode))
- (print-help-return-message)))))
+ (save-excursion
+ (let ((modifiers (event-modifiers (aref key 0)))
+ window position)
+ ;; For a mouse button event, go to the button it applies to
+ ;; to get the right key bindings. And go to the right place
+ ;; in case the keymap depends on where you clicked.
+ (if (or (memq 'click modifiers) (memq 'down modifiers)
+ (memq 'drag modifiers))
+ (setq window (posn-window (event-start (aref key 0)))
+ position (posn-point (event-start (aref key 0)))))
+ (if (windowp window)
+ (progn
+ (set-buffer (window-buffer window))
+ (goto-char position)))
+ (let ((defn (key-binding key)))
+ (if (or (null defn) (integerp defn))
+ (message "%s is undefined" (key-description key))
+ (with-output-to-temp-buffer "*Help*"
+ (princ (key-description key))
+ (if (windowp window)
+ (princ " at that spot"))
+ (princ " runs the command ")
+ (prin1 defn)
+ (princ "\n which is ")
+ (describe-function-1 defn nil)
+ (print-help-return-message)))))))
(defun describe-mode ()
"Display documentation of current major mode and minor modes.
(interactive)
(with-output-to-temp-buffer "*Help*"
(let ((minor-modes minor-mode-alist)
- (locals (buffer-local-variables)))
+ (first t))
(while minor-modes
(let* ((minor-mode (car (car minor-modes)))
- (indicator (car (cdr (car minor-modes))))
- (local-binding (assq minor-mode locals)))
+ (indicator (car (cdr (car minor-modes)))))
;; Document a minor mode if it is listed in minor-mode-alist,
;; bound locally in this buffer, non-nil, and has a function
;; definition.
- (if (and local-binding
- (cdr local-binding)
+ (if (and (symbol-value minor-mode)
(fboundp minor-mode))
(let ((pretty-minor-mode minor-mode))
(if (string-match "-mode$" (symbol-name minor-mode))
0 (match-beginning 0)))))
(while (and indicator (symbolp indicator))
(setq indicator (symbol-value indicator)))
- (princ (format "%s minor mode (indicator%s):\n"
- pretty-minor-mode indicator))
+ (if first
+ (princ "The minor modes are described first,
+followed by the major mode, which is described on the last page.\n\f\n"))
+ (setq first nil)
+ (princ (format "%s minor mode (%s):\n"
+ pretty-minor-mode
+ (if indicator
+ (format "indicator%s" indicator)
+ "no indicator")))
(princ (documentation minor-mode))
- (princ "\n\n"))))
+ (princ "\n\f\n"))))
(setq minor-modes (cdr minor-modes))))
(princ mode-name)
(princ " mode:\n")
(princ (documentation major-mode))
- (save-excursion
- (set-buffer standard-output)
- (help-mode))
+ (help-setup-xref (list #'help-xref-mode (current-buffer)) (interactive-p))
(print-help-return-message)))
;; So keyboard macro definitions are documented correctly
The prefix described consists of all but the last event
of the key sequence that ran this command."
(interactive)
- (let* ((key (this-command-keys))
- (prefix (make-vector (1- (length key)) nil))
- i)
- (setq i 0)
- (while (< i (length prefix))
- (aset prefix i (aref key i))
- (setq i (1+ i)))
- (describe-bindings prefix)))
+ (let* ((key (this-command-keys)))
+ (describe-bindings
+ (if (stringp key)
+ (substring key 0 (1- (length key)))
+ (let ((prefix (make-vector (1- (length key)) nil))
+ (i 0))
+ (while (< i (length prefix))
+ (aset prefix i (aref key i))
+ (setq i (1+ i)))
+ prefix)))))
;; Make C-h after a prefix, when not specifically bound,
;; run describe-prefix-bindings.
(setq prefix-help-command 'describe-prefix-bindings)
-(defun view-emacs-news ()
- "Display info on recent changes to Emacs."
- (interactive)
- (find-file-read-only (expand-file-name "NEWS" data-directory)))
+(defun view-emacs-news (&optional arg)
+ "Display info on recent changes to Emacs.
+With numeric argument display information on correspondingly older changes."
+ (interactive "P")
+ (let* ((arg (if arg (prefix-numeric-value arg) 0)))
+ (find-file-read-only
+ (expand-file-name (concat (make-string arg ?O) "NEWS")
+ data-directory))))
(defun view-emacs-FAQ ()
"Display the Emacs Frequently Asked Questions (FAQ) file."
(while (progn (move-to-column 50) (not (eobp)))
(search-forward " " nil t)
(insert "\n"))
- (help-mode))
+ (setq help-xref-stack nil
+ help-xref-stack-item nil))
(print-help-return-message)))
(defalias 'help 'help-for-help)
(make-help-screen help-for-help
- "a b c f C-f i k C-k l m n p s t v w C-c C-d C-n C-w, or ? for more help:"
+ "a b c C f F C-f i I k C-k l L m n p s t v w C-c C-d C-n C-p C-w; ? for help:"
"You have typed \\[help-command], the help character. Type a Help option:
\(Use SPC or DEL to scroll through this text. Type \\<help-map>\\[help-quit] to exit the Help command.)
b describe-bindings. Display table of all key bindings.
c describe-key-briefly. Type a command key sequence;
it prints the function name that sequence runs.
+C describe-coding-system. This describes either a specific coding system
+ (if you type its name) or the coding systems currently in use
+ (if you type just RET).
f describe-function. Type a function name and get documentation of it.
C-f Info-goto-emacs-command-node. Type a function name;
it takes you to the Info node for that command.
-F view-emacs-FAQ. Shows emacs frequently asked questions file.
i info. The info documentation reader.
+I describe-input-method. Describe a specific input method (if you type
+ its name) or the current input method (if you type just RET).
k describe-key. Type a command key sequence;
it displays the full documentation.
C-k Info-goto-emacs-key-command-node. Type a command key sequence;
it takes you to the Info node for the command bound to that key.
l view-lossage. Shows last 100 characters you typed.
-m describe-mode. Print documentation of current major mode,
- which describes the commands peculiar to it.
+L describe-language-environment. This describes either the a
+ specific language environment (if you type its name)
+ or the current language environment (if you type just RET).
+m describe-mode. Print documentation of current minor modes,
+ and the current major mode, including their special commands.
n view-emacs-news. Shows emacs news file.
p finder-by-keyword. Find packages matching a given topic keyword.
s describe-syntax. Display contents of syntax table, plus explanations
it displays the variable's documentation and value.
w where-is. Type command name; it prints which keystrokes
invoke that command.
-C-c print Emacs copying permission (General Public License).
-C-d print Emacs ordering information.
-C-n print news of recent Emacs changes.
-C-p print information about the GNU project.
-C-w print information on absence of warranty for GNU Emacs."
+
+F Display the frequently asked questions file.
+h Display the HELLO file which illustrates various scripts.
+C-c Display Emacs copying permission (General Public License).
+C-d Display Emacs ordering information.
+C-n Display news of recent Emacs changes.
+C-p Display information about the GNU project.
+C-w Display information on absence of warranty for GNU Emacs."
help-map)
;; Return a function which is called by the list containing point.
;; If that gives no function, return a function whose name is around point.
;; If that doesn't give a function, return nil.
(defun function-called-at-point ()
- (or (condition-case ()
- (save-excursion
- (save-restriction
- (narrow-to-region (max (point-min) (- (point) 1000)) (point-max))
- (backward-up-list 1)
- (forward-char 1)
- (let (obj)
- (setq obj (read (current-buffer)))
- (and (symbolp obj) (fboundp obj) obj))))
- (error nil))
- (condition-case ()
- (save-excursion
- (forward-sexp -1)
- (skip-chars-forward "'")
- (let ((obj (read (current-buffer))))
- (and (symbolp obj) (fboundp obj) obj)))
- (error nil))))
+ (let ((stab (syntax-table)))
+ (set-syntax-table emacs-lisp-mode-syntax-table)
+ (unwind-protect
+ (or (condition-case ()
+ (save-excursion
+ (save-restriction
+ (narrow-to-region (max (point-min) (- (point) 1000)) (point-max))
+ ;; Move up to surrounding paren, then after the open.
+ (backward-up-list 1)
+ (forward-char 1)
+ ;; If there is space here, this is probably something
+ ;; other than a real Lisp function call, so ignore it.
+ (if (looking-at "[ \t]")
+ (error "Probably not a Lisp function call"))
+ (let (obj)
+ (setq obj (read (current-buffer)))
+ (and (symbolp obj) (fboundp obj) obj))))
+ (error nil))
+ (condition-case ()
+ (save-excursion
+ (or (not (zerop (skip-syntax-backward "_w")))
+ (eq (char-syntax (following-char)) ?w)
+ (eq (char-syntax (following-char)) ?_)
+ (forward-sexp -1))
+ (skip-chars-forward "'")
+ (let ((obj (read (current-buffer))))
+ (and (symbolp obj) (fboundp obj) obj)))
+ (error nil)))
+ (set-syntax-table stab))))
(defun describe-function-find-file (function)
(let ((files load-history)
(setq val (completing-read (if fn
(format "Describe function (default %s): " fn)
"Describe function: ")
- obarray 'fboundp t))
+ obarray 'fboundp t nil nil (symbol-name fn)))
(list (if (equal val "")
fn (intern val)))))
- (with-output-to-temp-buffer "*Help*"
- (prin1 function)
- (princ ": ")
- (let* ((def (symbol-function function))
- (beg (if (commandp def) "an interactive " "a ")))
- (princ (cond ((or (stringp def)
- (vectorp def))
- "a keyboard macro")
- ((subrp def)
- (concat beg "built-in function"))
- ((byte-code-function-p def)
- (concat beg "compiled Lisp function"))
- ((symbolp def)
- (format "alias for `%s'" def))
- ((eq (car-safe def) 'lambda)
- (concat beg "Lisp function"))
- ((eq (car-safe def) 'macro)
- "a Lisp macro")
- ((eq (car-safe def) 'mocklisp)
- "a mocklisp function")
- ((eq (car-safe def) 'autoload)
- (format "%s autoloaded Lisp %s"
- (if (commandp def) "an interactive" "an")
- (if (nth 4 def) "macro" "function")
-;;; Including the file name made this line too long.
-;;; (nth 1 def)
- ))
- (t "")))
- (let ((file (describe-function-find-file function)))
- (if file
- (progn
- (princ " in `")
- ;; We used to add .el to the file name,
- ;; but that's completely wrong when the user used load-file.
- (princ file)
- (princ "'"))))
- (princ ".")
- (terpri)
- (let ((arglist (cond ((byte-code-function-p def)
- (car (append def nil)))
- ((eq (car-safe def) 'lambda)
- (nth 1 def))
- (t t))))
- (if (listp arglist)
- (progn
- (princ (cons function
- (mapcar (lambda (arg)
- (if (memq arg '(&optional &rest))
- arg
- (intern (upcase (symbol-name arg)))))
- arglist)))
- (terpri))))
- (if (documentation function)
+ (if function
+ (with-output-to-temp-buffer "*Help*"
+ (prin1 function)
+ ;; Use " is " instead of a colon so that
+ ;; it is easier to get out the function name using forward-sexp.
+ (princ " is ")
+ (describe-function-1 function nil)
+ (print-help-return-message)
+ (save-excursion
+ (set-buffer standard-output)
+ ;; Return the text we displayed.
+ (buffer-string)))
+ (message "You didn't specify a function")))
+
+(defun describe-function-1 (function parens)
+ (let* ((def (symbol-function function))
+ file-name string need-close
+ (beg (if (commandp def) "an interactive " "a ")))
+ (setq string
+ (cond ((or (stringp def)
+ (vectorp def))
+ "a keyboard macro")
+ ((subrp def)
+ (concat beg "built-in function"))
+ ((byte-code-function-p def)
+ (concat beg "compiled Lisp function"))
+ ((symbolp def)
+ (format "alias for `%s'" def))
+ ((eq (car-safe def) 'lambda)
+ (concat beg "Lisp function"))
+ ((eq (car-safe def) 'macro)
+ "a Lisp macro")
+ ((eq (car-safe def) 'mocklisp)
+ "a mocklisp function")
+ ((eq (car-safe def) 'autoload)
+ (setq file-name (nth 1 def))
+ (format "%s autoloaded Lisp %s"
+ (if (commandp def) "an interactive" "an")
+ (if (nth 4 def) "macro" "function")
+ ))
+ (t "")))
+ (when (and parens (not (equal string "")))
+ (setq need-close t)
+ (princ "("))
+ (princ string)
+ (or file-name
+ (setq file-name (describe-function-find-file function)))
+ (if file-name
+ (progn
+ (princ " in `")
+ ;; We used to add .el to the file name,
+ ;; but that's completely wrong when the user used load-file.
+ (princ file-name)
+ (princ "'")
+ ;; Make a hyperlink to the library.
+ (with-current-buffer "*Help*"
+ (save-excursion
+ (re-search-backward "`\\([^`']+\\)'" nil t)
+ (help-xref-button 1 #'(lambda (arg)
+ (let ((location
+ (find-function-noselect arg)))
+ (display-buffer (nth 0 location))
+ (goto-char (nth 1 location))))
+ function)))))
+ (if need-close (princ ")"))
+ (princ ".")
+ (terpri)
+ (let* ((inner-function (if (and (listp def) 'macro)
+ (cdr def)
+ def))
+ (arglist (cond ((byte-code-function-p inner-function)
+ (car (append inner-function nil)))
+ ((eq (car-safe inner-function) 'lambda)
+ (nth 1 inner-function))
+ (t t))))
+ (if (listp arglist)
+ (progn
+ (princ (cons function
+ (mapcar (lambda (arg)
+ (if (memq arg '(&optional &rest))
+ arg
+ (intern (upcase (symbol-name arg)))))
+ arglist)))
+ (terpri))))
+ (let ((doc (documentation function)))
+ (if doc
(progn (terpri)
- (princ (documentation function)))
- (princ "not documented"))
- )
- (print-help-return-message)
- (save-excursion
- (set-buffer standard-output)
- (help-mode)
- ;; Return the text we displayed.
- (buffer-string))))
+ (princ doc)
+ (help-setup-xref (list #'describe-function function) (interactive-p)))
+ (princ "not documented")))))
+;; We return 0 if we can't find a variable to return.
(defun variable-at-point ()
(condition-case ()
- (save-excursion
- (forward-sexp -1)
- (skip-chars-forward "'")
- (let ((obj (read (current-buffer))))
- (and (symbolp obj) (boundp obj) obj)))
- (error nil)))
+ (let ((stab (syntax-table)))
+ (unwind-protect
+ (save-excursion
+ (set-syntax-table emacs-lisp-mode-syntax-table)
+ (or (not (zerop (skip-syntax-backward "_w")))
+ (eq (char-syntax (following-char)) ?w)
+ (eq (char-syntax (following-char)) ?_)
+ (forward-sexp -1))
+ (skip-chars-forward "'")
+ (let ((obj (read (current-buffer))))
+ (or (and (symbolp obj) (boundp obj) obj)
+ 0)))
+ (set-syntax-table stab)))
+ (error 0)))
(defun describe-variable (variable)
"Display the full documentation of VARIABLE (a symbol).
(let ((v (variable-at-point))
(enable-recursive-minibuffers t)
val)
- (setq val (completing-read (if v
+ (setq val (completing-read (if (symbolp v)
(format "Describe variable (default %s): " v)
"Describe variable: ")
- obarray 'boundp t))
+ obarray 'boundp t nil nil
+ (if (symbolp v) (symbol-name v))))
(list (if (equal val "")
v (intern val)))))
- (with-output-to-temp-buffer "*Help*"
- (prin1 variable)
- (if (not (boundp variable))
- (princ " is void")
- (princ "'s value is ")
- (prin1 (symbol-value variable)))
- (terpri)
- (if (local-variable-p variable)
- (progn
- (princ (format "Local in buffer %s; " (buffer-name)))
- (if (not (default-boundp variable))
- (princ "globally void")
- (princ "global value is ")
- (prin1 (default-value variable)))
- (terpri)))
- (terpri)
- (princ "Documentation:")
- (terpri)
- (let ((doc (documentation-property variable 'variable-documentation)))
- (if doc
- (princ (substitute-command-keys doc))
- (princ "not documented as a variable.")))
- (print-help-return-message)
- (save-excursion
- (set-buffer standard-output)
- (help-mode)
- ;; Return the text we displayed.
- (buffer-string))))
+ (if (symbolp variable)
+ (let (valvoid)
+ (with-output-to-temp-buffer "*Help*"
+ (prin1 variable)
+ (if (not (boundp variable))
+ (progn
+ (princ " is void")
+ (terpri)
+ (setq valvoid t))
+ (princ "'s value is ")
+ (terpri)
+ (pp (symbol-value variable))
+ (terpri))
+ (if (local-variable-p variable)
+ (progn
+ (princ (format "Local in buffer %s; " (buffer-name)))
+ (if (not (default-boundp variable))
+ (princ "globally void")
+ (princ "global value is ")
+ (terpri)
+ (pp (default-value variable)))
+ (terpri)))
+ (terpri)
+ (save-current-buffer
+ (set-buffer standard-output)
+ (if (> (count-lines (point-min) (point-max)) 10)
+ (progn
+ (goto-char (point-min))
+ (if valvoid
+ (forward-line 1)
+ (forward-sexp 1)
+ (delete-region (point) (progn (end-of-line) (point)))
+ (insert "'s value is shown below.\n\n")
+ (save-excursion
+ (insert "\n\nValue:"))))))
+ (princ "Documentation:")
+ (terpri)
+ (let ((doc (documentation-property variable 'variable-documentation)))
+ (princ (or doc "not documented as a variable.")))
+ (help-setup-xref (list #'describe-variable variable) (interactive-p))
+
+ ;; Make a link to customize if this variable can be customized.
+ ;; Note, it is not reliable to test for a custom-type property
+ ;; because those are only present after the var's definition
+ ;; has been loaded.
+ (if (user-variable-p variable)
+ (let ((customize-label "customize"))
+ (terpri)
+ (terpri)
+ (princ (concat "You can " customize-label " this variable."))
+ (with-current-buffer "*Help*"
+ (save-excursion
+ (re-search-backward
+ (concat "\\(" customize-label "\\)") nil t)
+ (help-xref-button 1 #'(lambda (v)
+ (customize-variable v)) variable)
+ ))))
+
+ (print-help-return-message)
+ (save-excursion
+ (set-buffer standard-output)
+ ;; Return the text we displayed.
+ (buffer-string))))
+ (message "You did not specify a variable")))
-(defun where-is (definition)
+(defun describe-bindings (&optional prefix buffer)
+ "Show a list of all defined keys, and their definitions.
+We put that list in a buffer, and display the buffer.
+
+The optional argument PREFIX, if non-nil, should be a key sequence;
+then we display only bindings that start with that prefix.
+The optional argument BUFFER specifies which buffer's bindings
+to display (default, the current buffer)."
+ (interactive "P")
+ (or buffer (setq buffer (current-buffer)))
+ (with-current-buffer buffer
+ (describe-bindings-internal nil prefix))
+ (with-current-buffer "*Help*"
+ (help-setup-xref (list #'describe-bindings prefix buffer)
+ (interactive-p))))
+
+(defun where-is (definition &optional insert)
"Print message listing key sequences that invoke specified command.
-Argument is a command definition, usually a symbol with a function definition."
+Argument is a command definition, usually a symbol with a function definition.
+If INSERT (the prefix arg) is non-nil, insert the message in the buffer."
(interactive
(let ((fn (function-called-at-point))
(enable-recursive-minibuffers t)
"Where is command: ")
obarray 'fboundp t))
(list (if (equal val "")
- fn (intern val)))))
+ fn (intern val))
+ current-prefix-arg)))
(let* ((keys (where-is-internal definition overriding-local-map nil nil))
- (keys1 (mapconcat 'key-description keys ", ")))
- (if (> (length keys1) 0)
- (message "%s is on %s" definition keys1)
- (message "%s is not on any key" definition)))
+ (keys1 (mapconcat 'key-description keys ", "))
+ (standard-output (if insert (current-buffer) t)))
+ (if insert
+ (if (> (length keys1) 0)
+ (princ (format "%s (%s)" keys1 definition))
+ (princ (format "M-x %s RET" definition)))
+ (if (> (length keys1) 0)
+ (princ (format "%s is on %s" definition keys1))
+ (princ (format "%s is not on any key" definition)))))
nil)
-(defun command-apropos (string)
- "Like apropos but lists only symbols that are names of commands
-\(interactively callable functions). Argument REGEXP is a regular expression
-that is matched against command symbol names. Returns list of symbols and
-documentation found."
- (interactive "sCommand apropos (regexp): ")
- (let ((message
- (let ((standard-output (get-buffer-create "*Help*")))
- (print-help-return-message 'identity))))
- (if (apropos string t 'commandp t)
- (and message (message message)))))
-
-(defun locate-library (library &optional nosuffix)
- "Show the full path name of Emacs library LIBRARY.
+(defun locate-library (library &optional nosuffix path interactive-call)
+ "Show the precise file name of Emacs library LIBRARY.
This command searches the directories in `load-path' like `M-x load-library'
to find the file that `M-x load-library RET LIBRARY RET' would load.
Optional second arg NOSUFFIX non-nil means don't add suffixes `.elc' or `.el'
-to the specified name LIBRARY (a la calling `load' instead of `load-library')."
- (interactive "sLocate library: ")
- (catch 'answer
- (mapcar
- '(lambda (dir)
- (mapcar
- '(lambda (suf)
+to the specified name LIBRARY.
+
+If the optional third arg PATH is specified, that list of directories
+is used instead of `load-path'."
+ (interactive (list (read-string "Locate library: ")
+ nil nil
+ t))
+ (let (result)
+ (catch 'answer
+ (mapcar
+ (lambda (dir)
+ (mapcar
+ (lambda (suf)
(let ((try (expand-file-name (concat library suf) dir)))
(and (file-readable-p try)
(null (file-directory-p try))
(progn
- (message "Library is file %s" try)
+ (setq result try)
(throw 'answer try)))))
- (if nosuffix '("") '(".elc" ".el" ""))))
- load-path)
- (message "No library %s in search path" library)
- nil))
+ (if nosuffix
+ '("")
+ '(".elc" ".el" "")
+;;; load doesn't handle this yet.
+;;; (let ((basic '(".elc" ".el" ""))
+;;; (compressed '(".Z" ".gz" "")))
+;;; ;; If autocompression mode is on,
+;;; ;; consider all combinations of library suffixes
+;;; ;; and compression suffixes.
+;;; (if (rassq 'jka-compr-handler file-name-handler-alist)
+;;; (apply 'nconc
+;;; (mapcar (lambda (compelt)
+;;; (mapcar (lambda (baselt)
+;;; (concat baselt compelt))
+;;; basic))
+;;; compressed))
+;;; basic))
+ )))
+ (or path load-path)))
+ (and interactive-call
+ (if result
+ (message "Library is file %s" result)
+ (message "No library %s in search path" library)))
+ result))
+
+\f
+;;; 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'. On a character terminal highlighted
+references look like cross-references in info mode."
+ :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 "[back]"
+ "Label to use by `help-make-xrefs' for the go-back reference.")
+
+(defvar help-xref-symbol-regexp
+ (concat "\\(\\<\\(\\(variable\\|option\\)\\|"
+ "\\(function\\|command\\)\\|"
+ "\\(symbol\\)\\)\\s-+\\)?"
+ ;; 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.")
+
+(defvar help-xref-info-regexp
+ "\\<info\\s-+node\\s-`\\([^']+\\)'"
+ "Regexp matching doc string references to an Info node.")
+
+(defun help-setup-xref (item interactive-p)
+ "Invoked from commands using the \"*Help*\" buffer to install some xref info.
+
+ITEM is a (FUNCTION . ARGS) pair appropriate for recreating the help
+buffer after following a reference. INTERACTIVE-P is non-nil if the
+calling command was invoked interactively. In this case the stack of
+items for help buffer \"back\" buttons is cleared."
+ (if interactive-p
+ (setq help-xref-stack nil))
+ (setq help-xref-stack-item item))
+
+(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'.
+
+A special reference `back' is made to return back through a stack of
+help buffers. Variable `help-back-label' specifies the text for
+that."
+ (interactive "b")
+ (save-excursion
+ (set-buffer (or buffer (current-buffer)))
+ (goto-char (point-min))
+ ;; Skip the header-type info, though it might be useful to parse
+ ;; it at some stage (e.g. "function in `library'").
+ (forward-paragraph)
+ (let ((old-modified (buffer-modified-p)))
+ (let ((stab (syntax-table))
+ (case-fold-search t)
+ (inhibit-read-only t))
+ (set-syntax-table emacs-lisp-mode-syntax-table)
+ ;; The following should probably be abstracted out.
+ (unwind-protect
+ (progn
+ ;; Quoted symbols
+ (save-excursion
+ (while (re-search-forward help-xref-symbol-regexp nil t)
+ (let* ((data (match-string 6))
+ (sym (intern-soft data)))
+ (if sym
+ (cond
+ ((match-string 3) ; `variable' &c
+ (and (boundp sym) ; `variable' doesn't ensure
+ ; it's actually bound
+ (help-xref-button 6 #'describe-variable sym)))
+ ((match-string 4) ; `function' &c
+ (and (fboundp sym) ; similarly
+ (help-xref-button 6 #'describe-function sym)))
+ ((match-string 5)) ; nothing for symbol
+ ((and (boundp sym) (fboundp sym))
+ ;; We can't intuit whether to use the
+ ;; variable or function doc -- supply both.
+ (help-xref-button 6 #'help-xref-interned sym))
+ ((boundp sym)
+ (help-xref-button 6 #'describe-variable sym))
+ ((fboundp sym)
+ (help-xref-button 6 #'describe-function sym)))))))
+ ;; Info references
+ (save-excursion
+ (while (re-search-forward help-xref-info-regexp nil t)
+ (help-xref-button 1 #'Info-goto-node (list (match-data 1)))))
+ ;; An obvious case of a key substitution:
+ (save-excursion
+ (while (re-search-forward
+ "\\<M-x\\s-+\\(\\sw\\(\\sw\\|\\s_\\)+\\)" nil t)
+ (let ((sym (intern-soft (match-string 1))))
+ (if (fboundp sym)
+ (help-xref-button 1 #'describe-function sym)))))
+ ;; Look for commands in whole keymap substitutions:
+ (save-excursion
+ ;; Make sure to find the first keymap.
+ (goto-char (point-min))
+ ;; Find a header and the column at which the command
+ ;; name will be found.
+ (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 (looking-at "^\n?[^\n]")
+ (progn
+ (if (and (> (move-to-column col) 0)
+ (looking-at "\\(\\sw\\|\\s_\\)+$"))
+ ;;
+ (let ((sym (intern-soft (match-string 0))))
+ (if (fboundp sym)
+ (help-xref-button
+ 0 #'describe-function sym))))
+ t)
+ (zerop (forward-line))
+ (move-to-column 0)))))))
+ (set-syntax-table stab))
+ ;; Make a back-reference in this buffer if appropriate.
+ (when help-xref-stack
+ (goto-char (point-max))
+ (save-excursion
+ (insert "\n\n" help-back-label))
+ ;; Just to provide the match data:
+ (looking-at (concat "\n\n\\(" (regexp-quote help-back-label) "\\)"))
+ (help-xref-button 1 #'help-xref-go-back (current-buffer))))
+ ;; 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))))
+ (set-buffer-modified-p old-modified))))
+
+(defun help-xref-button (match-number function data)
+ "Make a hyperlink for cross-reference text previously matched.
+
+MATCH-NUMBER is the subexpression of interest in the last matched
+regexp. FUNCTION is a function to invoke when the button is
+activated, applied to DATA. DATA may be a single value or a list.
+See `help-make-xrefs'."
+ (add-text-properties (match-beginning match-number)
+ (match-end match-number)
+ (list 'mouse-face 'highlight
+ 'help-xref (cons function
+ (if (listp data)
+ data
+ (list data)))))
+ (if help-highlight-p
+ (put-text-property (match-beginning match-number)
+ (match-end match-number)
+ 'face help-highlight-face)))
+
+\f
+;; Additional functions for (re-)creating types of help buffers.
+(defun help-xref-interned (symbol)
+ "Follow a hyperlink which appeared to be an arbitrary interned SYMBOL.
+
+Both variable and function documentation are extracted into a single
+help buffer."
+ (let ((fdoc (describe-function symbol)))
+ (describe-variable symbol)
+ ;; We now have a help buffer on the variable. Insert the function
+ ;; text after it.
+ (goto-char (point-max))
+ (insert "\n\n" fdoc))
+ (goto-char (point-min))
+ (help-setup-xref (list #'help-xref-interned symbol) nil))
+
+(defun help-xref-mode (buffer)
+ "Do a `describe-mode' for the specified BUFFER."
+ (save-excursion
+ (set-buffer buffer)
+ (describe-mode)))
+\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))))
+
+(defun help-xref-go-back (buffer)
+ "Go back to the previous help buffer text using info on `help-xref-stack'."
+ (interactive)
+ (let (item position method args)
+ (with-current-buffer buffer
+ (when help-xref-stack
+ (setq help-xref-stack (cdr help-xref-stack)) ; due to help-follow
+ (setq item (car help-xref-stack)
+ position (car item)
+ method (cadr item)
+ args (cddr item))
+ (setq help-xref-stack (cdr help-xref-stack))))
+ (apply method args)
+ (goto-char position)))
+
+(defun help-go-back ()
+ (interactive)
+ (help-follow (1- (point-max))))
+
+(defun help-follow (&optional pos)
+ "Follow cross-reference at POS, defaulting to point.
+
+For the cross-reference format, see `help-make-xrefs'."
+ (interactive "d")
+ (let* ((help-data (or (and (not (= pos (point-max)))
+ (get-text-property pos 'help-xref))
+ (and (not (= pos (point-min)))
+ (get-text-property (1- pos) 'help-xref))))
+ (method (car help-data))
+ (args (cdr help-data)))
+ (setq help-xref-stack (cons (cons (point) help-xref-stack-item)
+ help-xref-stack))
+ (setq help-xref-stack-item nil)
+ (when help-data
+ ;; There is a reference at point. Follow it.
+ (apply method args))))
+
+;; For tabbing through buffer.
+(defun help-next-ref ()
+ "Find the next help cross-reference in the buffer."
+ (interactive)
+ (let (pos)
+ (while (not pos)
+ (if (get-text-property (point) 'help-xref) ; move off reference
+ (goto-char (or (next-single-property-change (point) 'help-xref)
+ (point))))
+ (cond ((setq pos (next-single-property-change (point) 'help-xref))
+ (if pos (goto-char pos)))
+ ((bobp)
+ (message "No cross references in the buffer.")
+ (setq pos t))
+ (t ; be circular
+ (goto-char (point-min)))))))
+
+(defun help-previous-ref ()
+ "Find the previous help cross-reference in the buffer."
+ (interactive)
+ (let (pos)
+ (while (not pos)
+ (if (get-text-property (point) 'help-xref) ; move off reference
+ (goto-char (or (previous-single-property-change (point) 'help-xref)
+ (point))))
+ (cond ((setq pos (previous-single-property-change (point) 'help-xref))
+ (if pos (goto-char pos)))
+ ((bobp)
+ (message "No cross references in the buffer.")
+ (setq pos t))
+ (t ; be circular
+ (goto-char (point-max)))))))
;;; help.el ends here
HCoop / bpt / emacs.git / blobdiff