-;;; help.el --- help commands for Emacs
-
-;; Copyright (C) 1985, 1986, 1993, 1994, 1998, 1999 Free Software Foundation, Inc.
-
-;; Maintainer: FSF
-;; Keywords: help, internal
-
-;; This file is part of GNU Emacs.
-
-;; GNU Emacs is free software; you can redistribute it and/or modify
-;; it under the terms of the GNU General Public License as published by
-;; the Free Software Foundation; either version 2, or (at your option)
-;; any later version.
-
-;; GNU Emacs is distributed in the hope that it will be useful,
-;; but WITHOUT ANY WARRANTY; without even the implied warranty of
-;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-;; 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, Inc., 59 Temple Place - Suite 330,
-;; Boston, MA 02111-1307, USA.
-
-;;; Commentary:
-
-;; This code implements GNU Emacs' on-line help system, the one invoked by
-;; `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.")
-
-(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" 'apropos-command)
-
-(define-key help-map "b" 'describe-bindings)
-
-(define-key help-map "c" 'describe-key-briefly)
-(define-key help-map "k" 'describe-key)
-
-(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 "4i" 'info-other-window)
-(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 "m" 'describe-mode)
-
-(define-key help-map "\C-n" 'view-emacs-news)
-(define-key help-map "n" 'view-emacs-news)
-
-(define-key help-map "p" 'finder-by-keyword)
-(autoload 'finder-by-keyword "finder"
- "Find packages matching a given keyword." t)
-
-(define-key help-map "s" 'describe-syntax)
-
-(define-key help-map "t" 'help-with-tutorial)
-
-(define-key help-map "w" 'where-is)
-
-(define-key help-map "v" 'describe-variable)
-
-(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 and navigating references in it.
-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 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-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.
- (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-finish)
-
-(defun help-quit ()
- "Just exit from the Help command's command loop."
- (interactive)
- nil)
-
-(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))
- (switch-to-buffer (create-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 filename data-directory))
- (goto-char (point-min))
- (search-forward "\n<<")
- (beginning-of-line)
- (delete-region (point) (progn (end-of-line) (point)))
- (let ((n (- (window-height (selected-window))
- (count-lines (point-min) (point))
- 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 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."
- (interactive "kDescribe key briefly: \nP")
- (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 (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))
- (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.
-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))
- (let ((first-message
- (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.
- 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
- (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 (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."
- (interactive "kDescribe key: ")
- (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 (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 (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 (interactive-p))
- (print-help-return-message)))))))
-
-(defun describe-mode ()
- "Display documentation of current major mode and minor modes.
-The major mode description comes first, followed by the minor modes,
-each on a separate page.
-
-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
-describes the minor mode."
- (interactive)
- (with-output-to-temp-buffer "*Help*"
- (when minor-mode-alist
- (princ "The major mode is described first.
-For minor modes, see following pages.\n\n"))
- (princ mode-name)
- (princ " mode:\n")
- (princ (documentation major-mode))
- (help-setup-xref (list #'help-xref-mode (current-buffer)) (interactive-p))
- (let ((minor-modes minor-mode-alist))
- (while minor-modes
- (let* ((minor-mode (car (car minor-modes)))
- (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 (symbol-value minor-mode)
- (fboundp 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)
- (boundp indicator)
- (not (eq indicator (symbol-value indicator))))
- (setq indicator (symbol-value indicator)))
- (princ "\n\f\n")
- (princ (format "%s minor mode (%s):\n"
- pretty-minor-mode
- (if indicator
- (format "indicator%s" indicator)
- "no indicator")))
- (princ (documentation minor-mode)))))
- (setq minor-modes (cdr minor-modes))))
- (print-help-return-message)))
-
-;; So keyboard macro definitions are documented correctly
-(fset 'defining-kbd-macro (symbol-function 'start-kbd-macro))
-
-(defun describe-distribution ()
- "Display info on how to obtain the latest version of GNU Emacs."
- (interactive)
- (find-file-read-only
- (expand-file-name "DISTRIB" data-directory)))
-
-(defun describe-copying ()
- "Display info on how you may redistribute copies of GNU Emacs."
- (interactive)
- (find-file-read-only
- (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)
- (describe-copying)
- (let (case-fold-search)
- (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 (&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."
- (interactive)
-;;; (find-file-read-only (expand-file-name "FAQ" data-directory))
- (info "(emacs-faq)"))
-
-(defun view-lossage ()
- "Display last 100 input keystrokes."
- (interactive)
- (with-output-to-temp-buffer "*Help*"
- (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"))
- (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 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 %THIS-KEY%, 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.
-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.
-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. 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. 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.
-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.
-
-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)
-
-(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))
- ;; 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)))
- (set-syntax-table stab))))
-
-(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
- (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
- (let ((fn (function-called-at-point))
- (enable-recursive-minibuffers t)
- val)
- (setq val (completing-read (if fn
- (format "Describe function (default %s): " fn)
- "Describe function: ")
- obarray 'fboundp t nil nil (symbol-name fn)))
- (list (if (equal val "")
- fn (intern val)))))
- (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 (interactive-p))
- (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 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
- (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)
- (while (symbolp (symbol-function def))
- (setq def (symbol-function def)))
- (format "an 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 %s"
- (if (commandp def) "an interactive" "an")
- (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 (symbol-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)))
- (pop-to-buffer (car location))
- (goto-char (cdr location))))
- function)))))
- (if need-close (princ ")"))
- (princ ".")
- (terpri)
- ;; Handle symbols aliased to other symbols.
- (setq def (indirect-function def))
- ;; If definition is a macro, find the function inside it.
- (if (eq (car-safe def) 'macro)
- (setq def (cdr def)))
- (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 (if (symbolp function) function "anonymous")
- (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 doc)
- (help-setup-xref (list #'describe-function function) interactive-p))
- (princ "not documented")))))
-
-(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
- (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).
-Returns the documentation as a string, also."
- (interactive
- (let ((v (variable-at-point))
- (enable-recursive-minibuffers t)
- val)
- (setq val (completing-read (if (symbolp v)
- (format "Describe variable (default %s): " v)
- "Describe variable: ")
- obarray 'boundp t nil nil
- (if (symbolp v) (symbol-name v))))
- (list (if (equal val "")
- v (intern val)))))
- (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 only for a custom-type property
- ;; because those are only present after the var's definition
- ;; has been loaded.
- (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)
- (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)
- ))))
- ;; 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 (symbol-file variable)))
- (when file-name
- (princ "\n\nDefined in `")
- (princ file-name)
- (princ "'.")
- (with-current-buffer "*Help*"
- (save-excursion
- (re-search-backward "`\\([^`']+\\)'" nil t)
- (help-xref-button 1 (lambda (arg)
- (let ((location
- (find-variable-noselect arg)))
- (pop-to-buffer (car location))
- (goto-char (cdr location))))
- 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 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 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
- (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))
- current-prefix-arg)))
- (let* ((keys (where-is-internal definition overriding-local-map nil nil))
- (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 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.
-
-If the optional third arg PATH is specified, that list of directories
-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))
- (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
- (setq result try)
- (throw 'answer try)))))
- (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'."
- :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
- "\\<[Ii]nfo[ \t\n]+node[ \t\n]+`\\([^']+\\)'"
- "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
- ;; 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)
- (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)))))))
- ;; An obvious case of a key substitution:
- (save-excursion
- (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)))))
- ;; 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 (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 #'describe-function sym))))
- (zerop (forward-line)))))))))
- (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'."
- ;; Don't mung properties we've added specially in some instances.
- (unless (get-text-property (match-beginning match-number) 'help-xref)
- (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 before it.
- (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."
- (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)
- "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
- (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 ()
- "Invoke the [back] button (if any) in the Help mode buffer."
- (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)))))))
-
-\f
-;;; Automatic resizing of temporary buffers.
-
-(defcustom temp-buffer-resize-mode nil
- "Non-nil means resize windows displaying temporary buffers.
-This makes the window the right height for its contents, but never
-more than `temp-buffer-max-height' nor less than `window-min-height'.
-This applies to `help', `apropos' and `completion' buffers, and some others.
-
-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)
- (temp-buffer-resize-mode (if value 1 -1)))
- :initialize 'custom-initialize-default
- :type 'boolean
- :group 'help
- :version "20.4")
-
-(defcustom temp-buffer-max-height (lambda (buffer) (/ (- (frame-height) 2) 2))
- "*Maximum height of a window displaying a temporary buffer.
-This is the maximum height (in text lines) which `resize-temp-buffer-window'
-will give to a window displaying a temporary buffer.
-It can also be a function which will be called with the object corresponding
-to the buffer to be displayed as argument and should return an integer
-positive number."
- :type '(choice integer function)
- :group 'help
- :version "20.4")
-
-(defun temp-buffer-resize-mode (arg)
- "Toggle the mode which that makes windows smaller for temporary buffers.
-With prefix argument ARG, turn the resizing of windows displaying temporary
-buffers on if ARG is positive or off otherwise.
-See the documentation of the variable `temp-buffer-resize-mode' for
-more information."
- (interactive "P")
- (let ((turn-it-on
- (if (null arg)
- (not (memq 'resize-temp-buffer-window temp-buffer-show-hook))
- (> (prefix-numeric-value arg) 0))))
- (if turn-it-on
- (progn
- ;; `help-mode-maybe' may add a `back' button and thus increase the
- ;; text size, so `resize-temp-buffer-window' must be run *after* it.
- (add-hook 'temp-buffer-show-hook 'resize-temp-buffer-window 'append)
- (setq temp-buffer-resize-mode t))
- (remove-hook 'temp-buffer-show-hook 'resize-temp-buffer-window)
- (setq temp-buffer-resize-mode nil))))
-
-(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
-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)
- (not (pos-visible-in-window-p (point-min)))
- (/= (frame-width) (window-width)))
- (let* ((max-height (if (functionp temp-buffer-max-height)
- (funcall temp-buffer-max-height (current-buffer))
- temp-buffer-max-height))
- (win-height (1- (window-height)))
- (min-height (1- window-min-height))
- (text-height (window-buffer-height(selected-window)))
- (new-height (max (min text-height max-height) min-height)))
- (enlarge-window (- new-height win-height)))))
-
-;;; help.el ends here
+;;; help.el --- help commands for Emacs
+
+;; Copyright (C) 1985, 1986, 1993, 1994, 1998, 1999, 2000, 2001, 2002
+;; Free Software Foundation, Inc.
+
+;; Maintainer: FSF
+;; Keywords: help, internal
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation; either version 2, or (at your option)
+;; any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+;; 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, Inc., 59 Temple Place - Suite 330,
+;; Boston, MA 02111-1307, USA.
+
+;;; Commentary:
+
+;; This code implements GNU Emacs' on-line help system, the one invoked by
+;; `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))
+
+;; This makes `with-output-to-temp-buffer' buffers use `help-mode'.
+(add-hook 'temp-buffer-setup-hook 'help-mode-setup)
+(add-hook 'temp-buffer-show-hook 'help-mode-finish)
+
+(defvar help-map (make-sparse-keymap)
+ "Keymap for characters following the Help key.")
+
+(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-e" 'view-emacs-problems)
+(define-key help-map "\C-f" 'view-emacs-FAQ)
+(define-key help-map "\C-m" 'view-order-manuals)
+(define-key help-map "\C-n" 'view-emacs-news)
+(define-key help-map "\C-p" 'describe-project)
+(define-key help-map "\C-t" 'view-todo)
+(define-key help-map "\C-w" 'describe-no-warranty)
+
+;; This does not fit the pattern, but it is natural given the C-\ command.
+(define-key help-map "\C-\\" 'describe-input-method)
+
+(define-key help-map "C" 'describe-coding-system)
+(define-key help-map "F" 'Info-goto-emacs-command-node)
+(define-key help-map "I" 'describe-input-method)
+(define-key help-map "K" 'Info-goto-emacs-key-command-node)
+(define-key help-map "L" 'describe-language-environment)
+(define-key help-map "S" 'info-lookup-symbol)
+
+(define-key help-map "a" 'apropos-command)
+
+(define-key help-map "b" 'describe-bindings)
+
+(define-key help-map "c" 'describe-key-briefly)
+
+(define-key help-map "e" 'view-echo-area-messages)
+
+(define-key help-map "f" 'describe-function)
+
+(define-key help-map "h" 'view-hello-file)
+
+(define-key help-map "i" 'info)
+(define-key help-map "4i" 'info-other-window)
+
+(define-key help-map "k" 'describe-key)
+
+(define-key help-map "l" 'view-lossage)
+
+(define-key help-map "m" 'describe-mode)
+
+(define-key help-map "n" 'view-emacs-news)
+
+(define-key help-map "p" 'finder-by-keyword)
+(autoload 'finder-by-keyword "finder"
+ "Find packages matching a given keyword." t)
+
+(define-key help-map "r" 'info-emacs-manual)
+
+(define-key help-map "s" 'describe-syntax)
+
+(define-key help-map "t" 'help-with-tutorial)
+
+(define-key help-map "w" 'where-is)
+
+(define-key help-map "v" 'describe-variable)
+
+(define-key help-map "q" 'help-quit)
+
+\f
+(defun help-quit ()
+ "Just exit from the Help command's command loop."
+ (interactive)
+ nil)
+
+(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.
+This function assumes that `standard-output' is the help buffer.
+It computes a message, and applies the optional argument FUNCTION to it.
+If FUNCTION is nil, it applies `message', thus displaying the message."
+ (and (not (get-buffer-window standard-output))
+ (let ((first-message
+ (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.
+ nil)
+ (display-buffer-reuse-frames
+ (setq help-return-method (cons (selected-window)
+ 'quit-window))
+ 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
+ (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 (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."))))))))
+
+;; So keyboard macro definitions are documented correctly
+(fset 'defining-kbd-macro (symbol-function 'start-kbd-macro))
+
+(defalias 'help 'help-for-help)
+(make-help-screen help-for-help
+ "a b c C e f F i I k C-k l L m p s t v w C-c C-d C-f C-n C-p C-t C-w or ? :"
+ "You have typed %THIS-KEY%, 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.
+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).
+e view-echo-area-messages. Show the `*Messages*' buffer.
+f describe-function. Type a function name and get documentation of it.
+F Info-goto-emacs-command-node. Type a function name;
+ it takes you to the Info node for that command.
+h Display the HELLO file which illustrates various scripts.
+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.
+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. Show last 100 characters you typed.
+L describe-language-environment. This describes either 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.
+p finder-by-keyword. Find packages matching a given topic keyword.
+s describe-syntax. Display contents of syntax table, plus explanations.
+S info-lookup-symbol. Display the definition of a specific symbol
+ as found in the manual for the language this buffer is written in.
+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 Display Emacs copying permission (GNU General Public License).
+C-d Display Emacs ordering information.
+C-e Display info about Emacs problems.
+C-f Display the Emacs FAQ.
+C-m Display how to order printed Emacs manuals.
+C-n Display news of recent Emacs changes.
+C-p Display information about the GNU project.
+C-t Display the Emacs TODO list.
+C-w Display information on absence of warranty for GNU Emacs."
+ help-map)
+
+\f
+
+(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."
+ (with-syntax-table emacs-lisp-mode-syntax-table
+ (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))
+ ;; 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 (read (current-buffer))))
+ (and (symbolp obj) (fboundp obj) obj))))
+ (error nil)))))
+
+\f
+;;; `User' help functions
+
+(defun describe-distribution ()
+ "Display info on how to obtain the latest version of GNU Emacs."
+ (interactive)
+ (view-file (expand-file-name "DISTRIB" data-directory)))
+
+(defun describe-copying ()
+ "Display info on how you may redistribute copies of GNU Emacs."
+ (interactive)
+ (view-file (expand-file-name "COPYING" data-directory))
+ (goto-char (point-min)))
+
+(defun describe-project ()
+ "Display info on the GNU project."
+ (interactive)
+ (view-file (expand-file-name "THE-GNU-PROJECT" data-directory))
+ (goto-char (point-min)))
+
+(defun describe-no-warranty ()
+ "Display info on all the kinds of warranty Emacs does NOT have."
+ (interactive)
+ (describe-copying)
+ (let (case-fold-search)
+ (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 (&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))
+ (file (cond ((eq arg 0) "NEWS")
+ ((eq arg 1) "ONEWS")
+ (t
+ (nth (- arg 2)
+ (nreverse (directory-files data-directory
+ nil "^ONEWS\\.[0-9]+$"
+ nil)))))))
+ (if file
+ (view-file (expand-file-name file data-directory))
+ (error "No such old news"))))
+
+(defun view-todo (&optional arg)
+ "Display the Emacs TODO list."
+ (interactive "P")
+ (view-file (expand-file-name "TODO" data-directory)))
+
+(defun view-echo-area-messages ()
+ "View the log of recent echo-area messages: the `*Messages*' buffer.
+The number of messages retained in that buffer
+is specified by the variable `message-log-max'."
+ (interactive)
+ (switch-to-buffer (get-buffer-create "*Messages*")))
+
+(defun view-order-manuals ()
+ "Display the Emacs ORDERS file."
+ (interactive)
+ (view-file (expand-file-name "ORDERS" data-directory))
+ (goto-address))
+
+(defun view-emacs-FAQ ()
+ "Display the Emacs Frequently Asked Questions (FAQ) file."
+ (interactive)
+ ;; (find-file-read-only (expand-file-name "FAQ" data-directory))
+ (info "(efaq)"))
+
+(defun view-emacs-problems ()
+ "Display info on known problems with Emacs and possible workarounds."
+ (interactive)
+ (view-file (expand-file-name "PROBLEMS" data-directory)))
+
+(defun view-lossage ()
+ "Display last 100 input keystrokes.
+
+To record all your input on a file, use `open-dribble-file'."
+ (interactive)
+ (help-setup-xref (list #'view-lossage) (interactive-p))
+ (with-output-to-temp-buffer (help-buffer)
+ (princ (mapconcat (lambda (key)
+ (if (or (integerp key) (symbolp key) (listp key))
+ (single-key-description key)
+ (prin1-to-string key nil)))
+ (recent-keys)
+ " "))
+ (with-current-buffer standard-output
+ (goto-char (point-min))
+ (while (progn (move-to-column 50) (not (eobp)))
+ (search-forward " " nil t)
+ (insert "\n")))
+ (print-help-return-message)))
+
+\f
+;; Key bindings
+
+(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)
+ (or buffer (setq buffer (current-buffer)))
+ (help-setup-xref (list #'describe-bindings prefix buffer) (interactive-p))
+ (with-current-buffer buffer
+ (describe-bindings-internal nil prefix)))
+
+;; This function used to be in keymap.c.
+(defun describe-bindings-internal (&optional menus prefix)
+ "Show a list of all defined keys, and their definitions.
+We put that list in a buffer, and display the buffer.
+
+The optional argument MENUS, if non-nil, says to mention menu bindings.
+\(Ordinarily these are omitted from the output.)
+The optional argument PREFIX, if non-nil, should be a key sequence;
+then we display only bindings that start with that prefix."
+ (interactive)
+ (let ((buf (current-buffer)))
+ (with-output-to-temp-buffer "*Help*"
+ (with-current-buffer standard-output
+ (describe-buffer-bindings buf prefix menus)))))
+
+(defun where-is (definition &optional insert)
+ "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
+ (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 'commandp t))
+ (list (if (equal val "") fn (intern val)) current-prefix-arg)))
+ (let ((func (indirect-function definition))
+ (defs nil)
+ (standard-output (if insert (current-buffer) t)))
+ (mapatoms (lambda (symbol)
+ (and (fboundp symbol)
+ (not (eq symbol definition))
+ (eq func (condition-case ()
+ (indirect-function symbol)
+ (error symbol)))
+ (push symbol defs))))
+ (princ (mapconcat
+ #'(lambda (symbol)
+ (let* ((remapped (remap-command symbol))
+ (keys (where-is-internal
+ symbol overriding-local-map nil nil remapped))
+ (keys (mapconcat 'key-description keys ", ")))
+ (if insert
+ (if (> (length keys) 0)
+ (if remapped
+ (format "%s (%s) (remapped from %s)"
+ keys remapped symbol)
+ (format "%s (%s)" keys symbol))
+ (format "M-x %s RET" symbol))
+ (if (> (length keys) 0)
+ (if remapped
+ (format "%s is remapped to %s which is on %s"
+ definition symbol keys)
+ (format "%s is on %s" symbol keys))
+ (format "%s is not on any key" symbol)))))
+ (cons definition defs)
+ ";\nand ")))
+ nil)
+
+(defun string-key-binding (key)
+ "Value is the binding of KEY in a string.
+If KEY is an event on a string, and that string has a `local-map'
+or `keymap' property, return the binding of KEY in the string's keymap."
+ (let* ((defn nil)
+ (start (when (vectorp key)
+ (if (memq (aref key 0)
+ '(mode-line header-line left-margin right-margin))
+ (event-start (aref key 1))
+ (and (consp (aref key 0))
+ (event-start (aref key 0))))))
+ (string-info (and (consp start) (nth 4 start))))
+ (when string-info
+ (let* ((string (car string-info))
+ (pos (cdr string-info))
+ (local-map (and (>= pos 0)
+ (< pos (length string))
+ (or (get-text-property pos 'local-map string)
+ (get-text-property pos 'keymap string)))))
+ (setq defn (and local-map (lookup-key local-map key)))))
+ defn))
+
+(defun help-key-description (key untranslated)
+ (let ((string (key-description key)))
+ (if (or (not untranslated)
+ (and (eq (aref untranslated 0) ?\e) (not (eq (aref key 0) ?\e))))
+ string
+ (let ((otherstring (key-description untranslated)))
+ (if (equal string otherstring)
+ string
+ (format "%s (translated from %s)" string otherstring))))))
+
+(defun describe-key-briefly (key &optional insert untranslated)
+ "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.
+If non-nil UNTRANSLATED is a vector of the untranslated events.
+It can also be a number in which case the untranslated events from
+the last key hit are used."
+ (interactive "kDescribe key briefly: \nP\np")
+ (if (numberp untranslated)
+ (setq untranslated (this-single-command-raw-keys)))
+ (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 (or (string-key-binding key)
+ (key-binding key)))
+ (key-desc (help-key-description key untranslated)))
+ (if (or (null defn) (integerp defn) (equal defn 'undefined))
+ (princ (format "%s is undefined" key-desc))
+ (princ (format (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)))))))))
+
+
+(defun describe-key (key &optional untranslated)
+ "Display documentation of the function invoked by KEY.
+KEY should be a key sequence--when calling from a program,
+pass a string or a vector.
+If non-nil UNTRANSLATED is a vector of the untranslated events.
+It can also be a number in which case the untranslated events from
+the last key hit are used."
+ (interactive "kDescribe key: \np")
+ (if (numberp untranslated)
+ (setq untranslated (this-single-command-raw-keys)))
+ (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)))))
+ (when (windowp window)
+ (set-buffer (window-buffer window))
+ (goto-char position))
+ (let ((defn (or (string-key-binding key) (key-binding key))))
+ (if (or (null defn) (integerp defn) (equal defn 'undefined))
+ (message "%s is undefined" (help-key-description key untranslated))
+ (help-setup-xref (list #'describe-function defn) (interactive-p))
+ (with-output-to-temp-buffer (help-buffer)
+ (princ (help-key-description key untranslated))
+ (if (windowp window)
+ (princ " at that spot"))
+ (princ " runs the command ")
+ (prin1 defn)
+ (princ "\n which is ")
+ (describe-function-1 defn)
+ (print-help-return-message)))))))
+
+\f
+(defun describe-mode (&optional buffer)
+ "Display documentation of current major mode and minor modes.
+The major mode description comes first, followed by the minor modes,
+each on a separate page.
+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
+describes the minor mode."
+ (interactive)
+ (help-setup-xref (list #'describe-mode (or buffer (current-buffer)))
+ (interactive-p))
+ ;; For the sake of help-do-xref and help-xref-go-back,
+ ;; don't switch buffers before calling `help-buffer'.
+ (with-output-to-temp-buffer (help-buffer)
+ (save-excursion
+ (when buffer (set-buffer buffer))
+ (when minor-mode-alist
+ (princ "The major mode is described first.
+For minor modes, see following pages.\n\n"))
+ (princ mode-name)
+ (princ " mode:\n")
+ (princ (documentation major-mode))
+ (let ((minor-modes minor-mode-alist))
+ (while minor-modes
+ (let* ((minor-mode (car (car minor-modes)))
+ (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 (boundp minor-mode)
+ (symbol-value minor-mode)
+ (fboundp minor-mode))
+ (let ((pretty-minor-mode minor-mode))
+ (if (string-match "\\(-minor\\)?-mode\\'"
+ (symbol-name minor-mode))
+ (setq pretty-minor-mode
+ (capitalize
+ (substring (symbol-name minor-mode)
+ 0 (match-beginning 0)))))
+ (while (and indicator (symbolp indicator)
+ (boundp indicator)
+ (not (eq indicator (symbol-value indicator))))
+ (setq indicator (symbol-value indicator)))
+ (princ "\n\f\n")
+ (princ (format "%s minor mode (%s):\n"
+ pretty-minor-mode
+ (if indicator
+ (format "indicator%s" indicator)
+ "no indicator")))
+ (princ (documentation minor-mode)))))
+ (setq minor-modes (cdr minor-modes))))
+ (print-help-return-message))))
+
+\f
+;;; Automatic resizing of temporary buffers.
+
+(defcustom temp-buffer-max-height (lambda (buffer) (/ (- (frame-height) 2) 2))
+ "*Maximum height of a window displaying a temporary buffer.
+This is the maximum height (in text lines) which `resize-temp-buffer-window'
+will give to a window displaying a temporary buffer.
+It can also be a function which will be called with the object corresponding
+to the buffer to be displayed as argument and should return an integer
+positive number."
+ :type '(choice integer function)
+ :group 'help
+ :version "20.4")
+
+(define-minor-mode temp-buffer-resize-mode
+ "Toggle the mode which makes windows smaller for temporary buffers.
+With prefix argument ARG, turn the resizing of windows displaying temporary
+buffers on if ARG is positive or off otherwise.
+This makes the window the right height for its contents, but never
+more than `temp-buffer-max-height' nor less than `window-min-height'.
+This applies to `help', `apropos' and `completion' buffers, and some others."
+ :global t :group 'help
+ (if temp-buffer-resize-mode
+ ;; `help-make-xrefs' may add a `back' button and thus increase the
+ ;; text size, so `resize-temp-buffer-window' must be run *after* it.
+ (add-hook 'temp-buffer-show-hook 'resize-temp-buffer-window 'append)
+ (remove-hook 'temp-buffer-show-hook 'resize-temp-buffer-window)))
+
+(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
+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)
+ (not (pos-visible-in-window-p (point-min)))
+ (/= (frame-width) (window-width)))
+ (fit-window-to-buffer
+ (selected-window)
+ (if (functionp temp-buffer-max-height)
+ (funcall temp-buffer-max-height (current-buffer))
+ temp-buffer-max-height))))
+
+;; Provide this for the sake of define-minor-mode which generates
+;; defcustoms which require 'help'.
+(provide 'help)
+
+;;; help.el ends here
HCoop / bpt / emacs.git / blobdiff