;;; help.el --- help commands for Emacs
-;; Copyright (C) 1985, 1986 Free Software Foundation, Inc.
+;; Copyright (C) 1985, 1986, 1993, 1994 Free Software Foundation, Inc.
;; Maintainer: FSF
;; Keywords: help, internal
;; along with GNU Emacs; see the file COPYING. If not, write to
;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+;;; Commentary:
+
+;; This code implements GNU Emac's on-line help system, the one invoked by
+;;`M-x help-for-help'.
+
;;; Code:
-(require 'help-screen)
+;; Get the macro make-help-screen when this is compiled,
+;; or run interpreted, but not when the compiled code is loaded.
+(eval-when-compile (require 'help-macro))
(defvar help-map (make-sparse-keymap)
"Keymap for characters following the Help key.")
+(defvar help-mode-map (make-sparse-keymap)
+ "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 "b" 'describe-bindings)
(define-key help-map "d" 'describe-function)
(define-key help-map "f" 'describe-function)
+(define-key help-map "F" 'view-emacs-FAQ)
+
(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 "n" 'view-emacs-news)
(define-key help-map "p" 'finder-by-keyword)
-(autoload 'finder-by-keyword "finder.el")
+(autoload 'finder-by-keyword "finder"
+ "Find packages matching a given keyword." t)
(define-key help-map "s" 'describe-syntax)
(define-key help-map "v" 'describe-variable)
+(define-key help-map "q" 'help-quit)
+
+(defvar help-font-lock-keywords
+ (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 2)
+ font-lock-function-name-face
+ font-lock-variable-name-face)
+ nil t))
+ ;;
+ ;; Words inside `' which tend to be symbol names.
+ (list (concat "`\\(" sym-char sym-char "+\\)'")
+ 1 'font-lock-reference-face t)
+ ;;
+ ;; CLisp `:' keywords as references.
+ (list (concat "\\<:" sym-char "+\\>") 0 'font-lock-reference-face t)))
+ "Default expressions to highlight in Help mode.")
+
+(defun help-mode ()
+ "Major mode for viewing help text.
+Entry to this mode runs the normal hook `help-mode-hook'.
+Commands:
+\\{help-mode-map}"
+ (interactive)
+ (kill-all-local-variables)
+ (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 '(help-font-lock-keywords))
+ (view-mode)
+ (run-hooks 'help-mode-hook))
+
+(defun help-quit ()
+ (interactive)
+ nil)
+
(defun help-with-tutorial ()
"Select the Emacs learn-by-doing tutorial."
(interactive)
(search-forward "\n<<")
(beginning-of-line)
(delete-region (point) (progn (end-of-line) (point)))
- (newline (- (window-height (selected-window))
+ (let ((n (- (window-height (selected-window))
(count-lines (point-min) (point))
- 6))
+ 6)))
+ (if (< n 12)
+ (newline n)
+ ;; Some people get confused by the large gap.
+ (newline (/ n 2))
+ (insert "[Middle of page left blank for didactic purposes. "
+ "Text continues below]")
+ (newline (- n (/ n 2)))))
(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: ")
+ ;; If this key seq ends with a down event, discard the
+ ;; following click or drag event. Otherwise that would
+ ;; erase the message.
+ (let ((type (aref key (1- (length key)))))
+ (if (listp type) (setq type (car type)))
+ (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))
Computes a message and applies the optional argument FUNCTION to it.
If FUNCTION is nil, applies `message' to it, thus printing it."
(and (not (get-buffer-window standard-output))
- (funcall (or function 'message)
- (concat
- (substitute-command-keys
- (if (one-window-p t)
- (if pop-up-windows
- "Type \\[delete-other-windows] to remove help window."
- "Type \\[switch-to-buffer] RET to remove help window.")
- "Type \\[switch-to-buffer-other-window] RET to restore the other window."))
- (substitute-command-keys
- " \\[scroll-other-window] to scroll the help.")))))
+ (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))
+ ;; 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))
+ "Type \\[switch-to-buffer-other-window] RET to restore the other window.")
+ (pop-up-windows
+ "Type \\[delete-other-windows] to remove help window.")
+ (t
+ "Type \\[switch-to-buffer] RET to remove help window."))))
+ (funcall (or function 'message)
+ (concat
+ (if first-message
+ (substitute-command-keys first-message)
+ "")
+ (if first-message " " "")
+ ;; If the help buffer will go in a separate frame,
+ ;; it's no use mentioning a command to scroll, so don't.
+ (if (or (member (buffer-name standard-output)
+ special-display-buffer-names)
+ (memq t (mapcar '(lambda (elt)
+ (string-match elt (buffer-name standard-output)))
+ special-display-regexps)))
+ nil
+ (if (or (member (buffer-name standard-output)
+ same-window-buffer-names)
+ (memq t (mapcar '(lambda (elt)
+ (string-match elt (buffer-name standard-output)))
+ same-window-regexps)))
+ ;; 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."
(interactive "kDescribe key: ")
+ ;; If this key seq ends with a down event, discard the
+ ;; following click or drag event. Otherwise that would
+ ;; erase the message.
+ (let ((type (aref key (1- (length key)))))
+ (if (listp type) (setq type (car type)))
+ (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))
(if (documentation defn)
(princ (documentation defn))
(princ "not documented"))
+ (save-excursion
+ (set-buffer standard-output)
+ (help-mode))
(print-help-return-message)))))
-(defun describe-mode (&optional minor)
- "Display documentation of current major mode.
-If optional MINOR is non-nil (or prefix argument is given if interactive),
-display documentation of active minor modes as well.
+(defun describe-mode ()
+ "Display documentation of current major mode and minor modes.
For this to work correctly for a minor mode, the mode's indicator variable
-(listed in `minor-mode-alist') must also be a function whose documentation
+\(listed in `minor-mode-alist') must also be a function whose documentation
describes the minor mode."
(interactive)
(with-output-to-temp-buffer "*Help*"
- (princ mode-name)
- (princ " Mode:\n")
- (princ (documentation major-mode))
(let ((minor-modes minor-mode-alist)
(locals (buffer-local-variables)))
(while minor-modes
(if (and local-binding
(cdr local-binding)
(fboundp minor-mode))
- (progn
- (princ (format "\n\n\n%s minor mode (indicator%s):\n"
- minor-mode indicator))
- (princ (documentation minor-mode)))))
+ (let ((pretty-minor-mode minor-mode))
+ (if (string-match "-mode$" (symbol-name minor-mode))
+ (setq pretty-minor-mode
+ (capitalize
+ (substring (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))
+ (princ (documentation minor-mode))
+ (princ "\n\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))
(print-help-return-message)))
;; So keyboard macro definitions are documented correctly
(expand-file-name "COPYING" data-directory))
(goto-char (point-min)))
+(defun describe-project ()
+ "Display info on the GNU project."
+ (interactive)
+ (find-file-read-only
+ (expand-file-name "GNU" data-directory))
+ (goto-char (point-min)))
+
(defun describe-no-warranty ()
"Display info on all the kinds of warranty Emacs does NOT have."
(interactive)
(search-forward "NO WARRANTY")
(recenter 0)))
+(defun describe-prefix-bindings ()
+ "Describe the bindings of the prefix used to reach this command.
+The prefix described consists of all but the last event
+of the key sequence that ran this command."
+ (interactive)
+ (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-FAQ ()
+ "Display the Emacs Frequently Asked Questions (FAQ) file."
+ (interactive)
+ (find-file-read-only (expand-file-name "FAQ" data-directory)))
+
(defun view-lossage ()
"Display last 100 input keystrokes."
(interactive)
(with-output-to-temp-buffer "*Help*"
- (princ (key-description (recent-keys)))
+ (princ (mapconcat (function (lambda (key)
+ (if (or (integerp key)
+ (symbolp key)
+ (listp key))
+ (single-key-description key)
+ (prin1-to-string key nil))))
+ (recent-keys)
+ " "))
(save-excursion
(set-buffer standard-output)
(goto-char (point-min))
(while (progn (move-to-column 50) (not (eobp)))
(search-forward " " nil t)
- (insert "\n")))
+ (insert "\n"))
+ (help-mode))
(print-help-return-message)))
+(defalias 'help 'help-for-help)
(make-help-screen help-for-help
- "A B C F I K L M N P S T V W C-c C-d C-n C-w. Type \\[help-for-help] again for more help: "
- "You have typed \\[help-for-help], the help character. Type a Help option:
-
-A command-apropos. Give a substring, and see a list of commands
- (functions interactively callable) that contain
- that substring. See also the apropos 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.
-F describe-function. Type a function name and get documentation of it.
-I info. The info documentation reader.
-K describe-key. Type a command key sequence;
- it displays the full documentation.
-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.
-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
-T help-with-tutorial. Select the Emacs learn-by-doing tutorial.
-V describe-variable. Type name of a variable;
- it displays the variable's documentation and value.
-W where-is. Type command name; it prints which keystrokes
- invoke that command.
+ "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:"
+ "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.)
+
+a command-apropos. Give a substring, and see a list of commands
+ (functions interactively callable) that contain
+ that substring. See also the apropos 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.
+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.
+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.
+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
+t help-with-tutorial. Select the Emacs learn-by-doing tutorial.
+v describe-variable. Type name of a variable;
+ 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."
help-map)
(and (symbolp obj) (fboundp obj) obj)))
(error nil))))
+(defun describe-function-find-file (function)
+ (let ((files load-history)
+ file functions)
+ (while files
+ (if (memq function (cdr (car files)))
+ (setq file (car (car files)) files nil))
+ (setq files (cdr files)))
+ file))
+
(defun describe-function (function)
"Display the full documentation of FUNCTION (a symbol)."
(interactive
(prin1 function)
(princ ": ")
(let* ((def (symbol-function function))
+ file-name
(beg (if (commandp def) "an interactive " "a ")))
- (princ (cond ((stringp def) "a keyboard macro.")
+ (princ (cond ((or (stringp def)
+ (vectorp def))
+ "a keyboard macro")
((subrp def)
- (concat beg "built-in function."))
+ (concat beg "built-in function"))
((byte-code-function-p def)
- (concat beg "compiled Lisp function."))
+ (concat beg "compiled Lisp function"))
((symbolp def)
- (format "alias for `%s'." def))
+ (format "alias for `%s'" def))
((eq (car-safe def) 'lambda)
- (concat beg "Lisp function."))
+ (concat beg "Lisp function"))
((eq (car-safe def) 'macro)
- "a Lisp macro.")
+ "a Lisp macro")
((eq (car-safe def) 'mocklisp)
- "a mocklisp function.")
+ "a mocklisp function")
((eq (car-safe def) 'autoload)
- (format "%s autoloaded Lisp %s."
+ (setq file-name (nth 1 def))
+ (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 "")))
+ (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 "'")))
+ (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)
- (princ (documentation function))
+ (progn (terpri)
+ (princ (documentation function)))
(princ "not documented"))
- (cond ((byte-code-function-p def)
- (save-excursion
- (set-buffer standard-output)
- (or (eq (char-after (1- (point-max))) ?\n)
- (terpri)))
- (terpri)
- (princ (car (append def nil))))
- ((eq (car-safe def) 'lambda)
- (save-excursion
- (set-buffer standard-output)
- (or (eq (char-after (1- (point-max))) ?\n)
- (terpri)))
- (terpri)
- (princ (nth 1 def)))))
+ )
(print-help-return-message)
- ;; Return the text we displayed.
- (save-excursion (set-buffer standard-output) (buffer-string))))
+ (save-excursion
+ (set-buffer standard-output)
+ (help-mode)
+ ;; Return the text we displayed.
+ (buffer-string))))
(defun variable-at-point ()
(condition-case ()
v (intern val)))))
(with-output-to-temp-buffer "*Help*"
(prin1 variable)
- (princ "'s value is ")
(if (not (boundp variable))
- (princ "void.")
+ (princ " is void")
+ (princ "'s value is ")
(prin1 (symbol-value variable)))
- (terpri) (terpri)
+ (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)))
(princ (substitute-command-keys doc))
(princ "not documented as a variable.")))
(print-help-return-message)
- ;; Return the text we displayed.
- (save-excursion (set-buffer standard-output) (buffer-string))))
-
-(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)
- (and message (message message)))))
+ (save-excursion
+ (set-buffer standard-output)
+ (help-mode)
+ ;; Return the text we displayed.
+ (buffer-string))))
+
+(defun where-is (definition)
+ "Print message listing key sequences that invoke specified command.
+Argument is a command definition, usually a symbol with a function definition."
+ (interactive
+ (let ((fn (function-called-at-point))
+ (enable-recursive-minibuffers t)
+ val)
+ (setq val (completing-read (if fn
+ (format "Where is command (default %s): " fn)
+ "Where is command: ")
+ obarray 'fboundp t))
+ (list (if (equal val "")
+ fn (intern val)))))
+ (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)))
+ nil)
(defun locate-library (library &optional nosuffix)
"Show the full path name of Emacs library LIBRARY.
HCoop / bpt / emacs.git / blobdiff