;;; help.el --- help commands for Emacs
-;; Copyright (C) 1985, 1986, 1993, 1994, 1998 Free Software Foundation, Inc.
+;; Copyright (C) 1985, 1986, 1993, 1994, 1998, 1999 Free Software Foundation, Inc.
;; Maintainer: FSF
;; Keywords: help, internal
;;; Commentary:
;; This code implements GNU Emacs' on-line help system, the one invoked by
-;;`M-x help-for-help'.
+;; `M-x help-for-help'.
;;; Code:
;; 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))
+(eval-when-compile (require 'view))
(defvar help-map (make-sparse-keymap)
"Keymap for characters following the Help key.")
(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)
+
(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'.
;; `help-mode-maybe'.
(run-hooks 'help-mode-hook))
-(defun help-mode-maybe ()
- (if (eq major-mode 'fundamental-mode)
- (help-mode))
+(defun help-mode-setup ()
+ (help-mode)
+ (setq buffer-read-only nil))
+
+(add-hook 'temp-buffer-setup-hook 'help-mode-setup)
+
+(defun help-mode-finish ()
(when (eq major-mode 'help-mode)
;; View mode's read-only status of existing *Help* buffer is lost
;; by with-output-to-temp-buffer.
(setq view-return-to-alist
(list (cons (selected-window) help-return-method))))
-(add-hook 'temp-buffer-show-hook 'help-mode-maybe)
+(add-hook 'temp-buffer-show-hook 'help-mode-finish)
(defun help-quit ()
"Just exit from the Help command's command loop."
(goto-char (point-min))
(set-buffer-modified-p nil))))
+(defun mode-line-key-binding (key)
+ "Value is the binding of KEY in the mode line or nil if none."
+ (let (string-info defn)
+ (when (and (eq 'mode-line (aref key 0))
+ (consp (setq string-info (nth 4 (event-start (aref key 1))))))
+ (let* ((string (car string-info))
+ (pos (cdr string-info))
+ (local-map (and (> pos 0)
+ (< pos (length string))
+ (get-text-property pos 'local-map string))))
+ (setq defn (and local-map (lookup-key local-map key)))))
+ defn))
+
(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."
(set-buffer (window-buffer window))
(goto-char position)))
;; Ok, now look up the key and name the command.
- (let ((defn (key-binding key))
+ (let ((defn (or (mode-line-key-binding key)
+ (key-binding key)))
(key-desc (key-description key)))
(if (or (null defn) (integerp defn))
(princ (format "%s is undefined" key-desc))
(progn
(set-buffer (window-buffer window))
(goto-char position)))
- (let ((defn (key-binding key)))
+ (let ((defn (or (mode-line-key-binding key) (key-binding key))))
(if (or (null defn) (integerp defn))
(message "%s is undefined" (key-description key))
(with-output-to-temp-buffer "*Help*"
(princ " runs the command ")
(prin1 defn)
(princ "\n which is ")
- (describe-function-1 defn nil)
+ (describe-function-1 defn nil (interactive-p))
(print-help-return-message)))))))
(defun describe-mode ()
(defun view-emacs-FAQ ()
"Display the Emacs Frequently Asked Questions (FAQ) file."
(interactive)
- (find-file-read-only (expand-file-name "FAQ" data-directory)))
+;;; (find-file-read-only (expand-file-name "FAQ" data-directory))
+ (info "(emacs-faq)"))
(defun view-lossage ()
"Display last 100 input keystrokes."
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).
+C-i info-lookup-symbol. Display the definition of a specific symbol
+ as found in the manual for the language this buffer is written in.
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.
+l view-lossage. Show last 100 characters you typed.
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.
+n view-emacs-news. Display news of recent Emacs changes.
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.
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 ()
+ "Return a function around point or else called by the list containing point.
+If that doesn't give a function, return nil."
(let ((stab (syntax-table)))
(set-syntax-table emacs-lisp-mode-syntax-table)
(unwind-protect
(or (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))
+ (condition-case ()
(save-excursion
(save-restriction
(narrow-to-region (max (point-min) (- (point) 1000)) (point-max))
(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)
+(defvar symbol-file-load-history-loaded nil
+ "Non-nil means we have loaded the file `fns-VERSION.el' in `exec-directory'.
+That file records the part of `load-history' for preloaded files,
+which is cleared out before dumping to make Emacs smaller.")
+
+(defun symbol-file (function)
+ "Return the input source from which FUNCTION was loaded.
+The value is normally a string that was passed to `load':
+either an absolute file name, or a library name
+\(with no directory name and no `.el' or `.elc' at the end).
+It can also be nil, if the definition is not associated with any file."
+ (unless symbol-file-load-history-loaded
+ (load (expand-file-name
+ ;; fns-XX.YY.ZZ.el does not work on DOS filesystem.
+ (if (eq system-type 'ms-dos)
+ "fns.el"
+ (format "fns-%s.el" emacs-version))
+ exec-directory)
+ ;; The file name fns-%s.el already has a .el extension.
+ nil nil t)
+ (setq symbol-file-load-history-loaded t))
(let ((files load-history)
file functions)
(while files
;; 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)
+ (describe-function-1 function nil (interactive-p))
(print-help-return-message)
(save-excursion
(set-buffer standard-output)
(buffer-string)))
(message "You didn't specify a function")))
-(defun describe-function-1 (function parens)
- (let* ((def (symbol-function function))
+(defun describe-function-1 (function parens interactive-p)
+ (let* ((def (if (symbolp function)
+ (symbol-function function)
+ function))
file-name string need-close
(beg (if (commandp def) "an interactive " "a ")))
(setq string
((symbolp def)
(while (symbolp (symbol-function def))
(setq def (symbol-function def)))
- (format "alias for `%s'" def))
+ (format "an alias for `%s'" def))
((eq (car-safe def) 'lambda)
(concat beg "Lisp function"))
((eq (car-safe def) 'macro)
"a mocklisp function")
((eq (car-safe def) 'autoload)
(setq file-name (nth 1 def))
- (format "%s autoloaded Lisp %s"
+ (format "%s autoloaded %s"
(if (commandp def) "an interactive" "an")
- (if (nth 4 def) "macro" "function")
+ (if (eq (nth 4 def) 'keymap) "keymap"
+ (if (nth 4 def) "Lisp macro" "Lisp function"))
))
+ ;; perhaps use keymapp here instead
+ ((eq (car-safe def) 'keymap)
+ (let ((is-full nil)
+ (elts (cdr-safe def)))
+ (while elts
+ (if (char-table-p (car-safe elts))
+ (setq is-full t
+ elts nil))
+ (setq elts (cdr-safe elts)))
+ (if is-full
+ "a full keymap"
+ "a sparse keymap")))
(t "")))
(when (and parens (not (equal string "")))
(setq need-close t)
(princ "("))
(princ string)
+ (with-current-buffer "*Help*"
+ (save-excursion
+ (save-match-data
+ (if (re-search-backward "alias for `\\([^`']+\\)'" nil t)
+ (help-xref-button 1 #'describe-function def)))))
(or file-name
- (setq file-name (describe-function-find-file function)))
+ (setq file-name (symbol-file function)))
(if file-name
(progn
(princ " in `")
(t t))))
(if (listp arglist)
(progn
- (princ (cons function
+ (princ (cons (if (symbolp function) function "anonymous")
(mapcar (lambda (arg)
(if (memq arg '(&optional &rest))
arg
(if doc
(progn (terpri)
(princ doc)
- (help-setup-xref (list #'describe-function function) (interactive-p)))
+ (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 ()
+ "Return the bound variable symbol found around point.
+Return 0 if there is no such symbol."
(condition-case ()
(let ((stab (syntax-table)))
(unwind-protect
;; Note, it is not reliable to test only for a custom-type property
;; because those are only present after the var's definition
;; has been loaded.
- (if (or (user-variable-p variable) (get variable 'custom-type))
+ (if (or (get variable 'custom-type) ; after defcustom
+ (get variable 'custom-loads) ; from loaddefs.el
+ (get variable 'standard-value)) ; from cus-start.el
(let ((customize-label "customize"))
(terpri)
(terpri)
;; Make a hyperlink to the library if appropriate. (Don't
;; change the format of the buffer's initial line in case
;; anything expects the current format.)
- (let ((file-name (describe-function-find-file variable)))
+ (let ((file-name (symbol-file variable)))
(when file-name
(princ "\n\nDefined in `")
(princ file-name)
(interactive-p))))
(defun where-is (definition &optional insert)
- "Print message listing key sequences that invoke specified command.
+ "Print message listing key sequences that invoke the command 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
to the specified name LIBRARY.
If the optional third arg PATH is specified, that list of directories
-is used instead of `load-path'."
+is used instead of `load-path'.
+
+When called from a program, the file name is normaly returned as a
+string. When run interactively, the argument INTERACTIVE-CALL is t,
+and the file name is displayed in the echo area."
(interactive (list (read-string "Locate library: ")
nil nil
t))
(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."
+`help-highlight-face'."
:group 'help
:version "20.3"
:type 'boolean)
distinguish references to variables, functions and symbols.")
(defvar help-xref-info-regexp
- "\\<info\\s-+node\\s-`\\([^']+\\)'"
+ "\\<[Ii]nfo[ \t\n]+node[ \t\n]+`\\([^']+\\)'"
"Regexp matching doc string references to an Info node.")
(defun help-setup-xref (item interactive-p)
;; The following should probably be abstracted out.
(unwind-protect
(progn
+ ;; Info references
+ (save-excursion
+ (while (re-search-forward help-xref-info-regexp nil t)
+ (let ((data (match-string 1)))
+ (save-match-data
+ (unless (string-match "^([^)]+)" data)
+ (setq data (concat "(emacs)" data))))
+ (help-xref-button 1 #'info data))))
;; Quoted symbols
(save-excursion
(while (re-search-forward help-xref-symbol-regexp nil t)
(and (fboundp sym) ; similarly
(help-xref-button 6 #'describe-function sym)))
((match-string 5)) ; nothing for symbol
- ((and (boundp sym) (fboundp sym))
+ ((or (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 (match-string 1))))
+ (help-xref-button 6 #'help-xref-interned sym)))))))
;; An obvious case of a key substitution:
(save-excursion
- (while (re-search-forward
- "\\<M-x\\s-+\\(\\sw\\(\\sw\\|\\s_\\)+\\)" nil t)
+ (while (re-search-forward
+ ;; Assume command name is only word characters
+ ;; and dashes to get things like `use M-x foo.'.
+ "\\<M-x\\s-+\\(\\sw\\(\\sw\\|-\\)+\\)" nil t)
(let ((sym (intern-soft (match-string 1))))
(if (fboundp sym)
(help-xref-button 1 #'describe-function sym)))))
(while
;; Ignore single blank lines in table, but not
;; double ones, which should terminate it.
- (and (looking-at "^\n?[^\n]")
+ (and (not (looking-at "\n\\s-*\n"))
(progn
- (if (and (> (move-to-column col) 0)
- (looking-at "\\(\\sw\\|\\s_\\)+$"))
- ;;
+ (and (eolp) (forward-line))
+ (end-of-line)
+ (skip-chars-backward "^\t\n")
+ (if (and (>= (current-column) col)
+ (looking-at "\\(\\sw\\|-\\)+$"))
(let ((sym (intern-soft (match-string 0))))
(if (fboundp sym)
(help-xref-button
0 #'describe-function sym))))
- t)
- (zerop (forward-line))
- (move-to-column 0)))))))
+ (zerop (forward-line)))))))))
(set-syntax-table stab))
;; Make a back-reference in this buffer if appropriate.
(when help-xref-stack
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))
- (let ((inhibit-read-only t))
- (insert "\n\n" fdoc)))
- (goto-char (point-min))
- (help-setup-xref (list #'help-xref-interned symbol) nil))
+ (let ((fdoc (when (fboundp symbol) (describe-function symbol))))
+ (when (or (boundp symbol) (not fdoc))
+ (describe-variable symbol)
+ ;; We now have a help buffer on the variable. Insert the function
+ ;; text before it.
+ (when fdoc
+ (with-current-buffer "*Help*"
+ (goto-char (point-min))
+ (let ((inhibit-read-only t))
+ (insert fdoc "\n\n" (symbol-name symbol) " is also a variable.\n\n"))
+ (help-setup-xref (list #'help-xref-interned symbol) nil))))))
(defun help-xref-mode (buffer)
"Do a `describe-mode' for the specified BUFFER."
(help-follow pos))))
(defun help-xref-go-back (buffer)
- "Go back to the previous help buffer text using info on `help-xref-stack'."
- (interactive)
+ "From BUFFER, go back to previous help buffer text using `help-xref-stack'."
(let (item position method args)
(with-current-buffer buffer
(when help-xref-stack
(goto-char position)))
(defun help-go-back ()
+ "Invoke the [back] button (if any) in the Help mode buffer."
(interactive)
(help-follow (1- (point-max))))
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))))
+ (unless pos
+ (setq pos (point)))
+ (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))
+ ;; 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))
+ (list #'help-xref-interned sym)))))
(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
+ (setq help-xref-stack (cons (cons (point) help-xref-stack-item)
+ help-xref-stack))
+ (setq help-xref-stack-item nil)
;; There is a reference at point. Follow it.
(apply method args))))
more than `temp-buffer-max-height' nor less than `window-min-height'.
This applies to `help', `apropos' and `completion' buffers, and some others.
-This variable must be modified via \\[customize] in order to have an effect."
+Setting this variable directly does not take effect;
+use either \\[customize] or the function `temp-buffer-resize-mode'."
:get (lambda (symbol)
(and (memq 'resize-temp-buffer-window temp-buffer-show-hook) t))
:set (lambda (symbol value)
(defun resize-temp-buffer-window ()
"Resize the current window to fit its contents.
Will not make it higher than `temp-buffer-max-height' nor smaller than
-`window-min-height'. Do nothing if it is the only window on its frame, if it
+`window-min-height'. Do nothing if it is the only window on its frame, if it
is not as wide as the frame or if some of the window's contents are scrolled
out of view."
(unless (or (one-window-p 'nomini)