;;; 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'.
(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.
;; 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)
+(defun describe-function-1 (function parens interactive-p)
(let* ((def (if (symbolp function)
(symbol-function function)
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)
(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")))))
(defun variable-at-point ()
;; 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)
(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)
- (let ((data (match-string 1)))
- (save-match-data
- (unless (string-match "^([^)]+)" data)
- (setq data (concat "(emacs)" data))))
- (help-xref-button 1 #'info data))))
+ (help-xref-button 6 #'help-xref-interned sym)))))))
;; An obvious case of a key substitution:
(save-excursion
(while (re-search-forward
(while
;; Ignore single blank lines in table, but not
;; double ones, which should terminate it.
- (and (looking-at "^\n?[^\n\t ]")
+ (and (not (looking-at "\n\\s-*\n"))
(progn
- (if (and (> (move-to-column col) 0)
- (looking-at "\\(\\sw\\|-\\)+$"))
- ;;
+ (and (eolp) (forward-line))
+ (end-of-line)
+ (skip-chars-backward "^\t\n")
+ (if (and (>= (current-column) col)
+ (looking-at "\\(\\sw\\|-\\)+$"))
(let ((sym (intern-soft (match-string 0))))
(if (fboundp sym)
(help-xref-button
0 #'describe-function sym))))
- t)
- (progn
- (end-of-line)
- (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."
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)