mirror of
https://git.savannah.gnu.org/git/emacs.git
synced 2024-12-04 08:47:11 +00:00
97e48510ad
a5f7c26907
(origin/emacs-27) * admin/authors.el: Add an author alias.d87a4d1f4e
Limit RLIMIT_NOFILE to FD_SETSIZE on macOSe5ca8e5e73
Fix Elisp manual entry on 'set-window-configuration'485f24223f
; Update ChangeLog.38f200254fb
; Update etc/AUTHORSc7adc851ad
* admin/authors.el: Add missing author aliases.4acdd7fe58
Fix edge case errors in filename-matching regexps5f36e21fe5
Clarify the doc string of 'yank'13301d4266
New function erc-track-switch-buffer-other-window38f7538d8f
New function erc-switch-to-buffer-other-window # Conflicts: # etc/NEWS
1462 lines
59 KiB
EmacsLisp
1462 lines
59 KiB
EmacsLisp
;;; help.el --- help commands for Emacs -*- lexical-binding:t -*-
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;; Copyright (C) 1985-1986, 1993-1994, 1998-2020 Free Software
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;; Foundation, Inc.
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;; Maintainer: emacs-devel@gnu.org
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;; Keywords: help, internal
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;; Package: emacs
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;; This file is part of GNU Emacs.
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;; GNU Emacs is free software: you can redistribute it and/or modify
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;; it under the terms of the GNU General Public License as published by
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;; the Free Software Foundation, either version 3 of the License, or
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;; (at your option) any later version.
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;; GNU Emacs is distributed in the hope that it will be useful,
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;; but WITHOUT ANY WARRANTY; without even the implied warranty of
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;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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;; GNU General Public License for more details.
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;; You should have received a copy of the GNU General Public License
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;; along with GNU Emacs. If not, see <https://www.gnu.org/licenses/>.
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;;; Commentary:
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;; This code implements GNU Emacs's built-in help system, the one invoked by
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;; `M-x help-for-help'.
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;;; Code:
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;; Get the macro make-help-screen when this is compiled,
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;; or run interpreted, but not when the compiled code is loaded.
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(eval-when-compile (require 'help-macro))
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;; This makes `with-output-to-temp-buffer' buffers use `help-mode'.
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(add-hook 'temp-buffer-setup-hook 'help-mode-setup)
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(add-hook 'temp-buffer-show-hook 'help-mode-finish)
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;; `help-window-point-marker' is a marker you can move to a valid
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;; position of the buffer shown in the help window in order to override
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;; the standard positioning mechanism (`point-min') chosen by
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;; `with-output-to-temp-buffer' and `with-temp-buffer-window'.
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;; `with-help-window' has this point nowhere before exiting. Currently
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;; used by `view-lossage' to assert that the last keystrokes are always
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;; visible.
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(defvar help-window-point-marker (make-marker)
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"Marker to override default `window-point' in help windows.")
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(defvar help-window-old-frame nil
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"Frame selected at the time `with-help-window' is invoked.")
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(defvar help-map
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(let ((map (make-sparse-keymap)))
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(define-key map (char-to-string help-char) 'help-for-help)
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(define-key map [help] 'help-for-help)
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(define-key map [f1] 'help-for-help)
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(define-key map "." 'display-local-help)
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(define-key map "?" 'help-for-help)
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(define-key map "\C-a" 'about-emacs)
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(define-key map "\C-c" 'describe-copying)
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(define-key map "\C-d" 'view-emacs-debugging)
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(define-key map "\C-e" 'view-external-packages)
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(define-key map "\C-f" 'view-emacs-FAQ)
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(define-key map "\C-m" 'view-order-manuals)
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(define-key map "\C-n" 'view-emacs-news)
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(define-key map "\C-o" 'describe-distribution)
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(define-key map "\C-p" 'view-emacs-problems)
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(define-key map "\C-s" 'search-forward-help-for-help)
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(define-key map "\C-t" 'view-emacs-todo)
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(define-key map "\C-w" 'describe-no-warranty)
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;; This does not fit the pattern, but it is natural given the C-\ command.
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(define-key map "\C-\\" 'describe-input-method)
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(define-key map "C" 'describe-coding-system)
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(define-key map "F" 'Info-goto-emacs-command-node)
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(define-key map "I" 'describe-input-method)
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(define-key map "K" 'Info-goto-emacs-key-command-node)
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(define-key map "L" 'describe-language-environment)
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(define-key map "S" 'info-lookup-symbol)
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(define-key map "a" 'apropos-command)
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(define-key map "b" 'describe-bindings)
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(define-key map "c" 'describe-key-briefly)
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(define-key map "d" 'apropos-documentation)
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(define-key map "e" 'view-echo-area-messages)
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(define-key map "f" 'describe-function)
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(define-key map "g" 'describe-gnu-project)
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(define-key map "h" 'view-hello-file)
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(define-key map "i" 'info)
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(define-key map "4i" 'info-other-window)
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(define-key map "k" 'describe-key)
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(define-key map "l" 'view-lossage)
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(define-key map "m" 'describe-mode)
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(define-key map "o" 'describe-symbol)
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(define-key map "n" 'view-emacs-news)
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(define-key map "p" 'finder-by-keyword)
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(define-key map "P" 'describe-package)
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(define-key map "r" 'info-emacs-manual)
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(define-key map "s" 'describe-syntax)
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(define-key map "t" 'help-with-tutorial)
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(define-key map "w" 'where-is)
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(define-key map "v" 'describe-variable)
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(define-key map "q" 'help-quit)
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map)
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"Keymap for characters following the Help key.")
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(define-key global-map (char-to-string help-char) 'help-command)
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(define-key global-map [help] 'help-command)
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(define-key global-map [f1] 'help-command)
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(fset 'help-command help-map)
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;; insert-button makes the action nil if it is not store somewhere
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(defvar help-button-cache nil)
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(defun help-quit ()
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"Just exit from the Help command's command loop."
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(interactive)
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nil)
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(defvar help-return-method nil
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"What to do to \"exit\" the help buffer.
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This is a list
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(WINDOW . t) delete the selected window (and possibly its frame,
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see `quit-window'), go to WINDOW.
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(WINDOW . quit-window) do quit-window, then select WINDOW.
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(WINDOW BUF START POINT) display BUF at START, POINT, then select WINDOW.")
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(define-obsolete-function-alias 'print-help-return-message 'help-print-return-message "23.2")
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(defun help-print-return-message (&optional function)
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"Display or return message saying how to restore windows after help command.
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This function assumes that `standard-output' is the help buffer.
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It computes a message, and applies the optional argument FUNCTION to it.
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If FUNCTION is nil, it applies `message', thus displaying the message.
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In addition, this function sets up `help-return-method', which see, that
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specifies what to do when the user exits the help buffer.
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Do not call this in the scope of `with-help-window'."
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(and (not (get-buffer-window standard-output))
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(let ((first-message
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(cond ((or
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pop-up-frames
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(special-display-p (buffer-name standard-output)))
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(setq help-return-method (cons (selected-window) t))
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;; If the help output buffer is a special display buffer,
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;; don't say anything about how to get rid of it.
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;; First of all, the user will do that with the window
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;; manager, not with Emacs.
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;; Secondly, the buffer has not been displayed yet,
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;; so we don't know whether its frame will be selected.
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nil)
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((not (one-window-p t))
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(setq help-return-method
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(cons (selected-window) 'quit-window))
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"Type \\[display-buffer] RET to restore the other window.")
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(pop-up-windows
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(setq help-return-method (cons (selected-window) t))
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"Type \\[delete-other-windows] to remove help window.")
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(t
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(setq help-return-method
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(list (selected-window) (window-buffer)
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(window-start) (window-point)))
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"Type \\[switch-to-buffer] RET to remove help window."))))
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(funcall (or function 'message)
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(concat
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(if first-message
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(substitute-command-keys first-message))
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(if first-message " ")
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;; If the help buffer will go in a separate frame,
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;; it's no use mentioning a command to scroll, so don't.
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(if (or pop-up-windows
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(special-display-p (buffer-name standard-output)))
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nil
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(if (same-window-p (buffer-name standard-output))
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;; Say how to scroll this window.
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(substitute-command-keys
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"\\[scroll-up] to scroll the help.")
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;; Say how to scroll some other window.
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(substitute-command-keys
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"\\[scroll-other-window] to scroll the help."))))))))
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;; So keyboard macro definitions are documented correctly
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(fset 'defining-kbd-macro (symbol-function 'start-kbd-macro))
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(defalias 'help 'help-for-help-internal)
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;; find-function can find this.
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(defalias 'help-for-help 'help-for-help-internal)
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;; It can't find this, but nobody will look.
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(make-help-screen help-for-help-internal
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(purecopy "Type a help option: [abcCdefFgiIkKlLmnprstvw.] C-[cdefmnoptw] or ?")
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;; Don't purecopy this one, because it's not evaluated (it's
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;; directly used as a docstring in a function definition, so it'll
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;; be moved to the DOC file anyway: no need for purecopying it).
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"You have typed %THIS-KEY%, the help character. Type a Help option:
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\(Use SPC or DEL to scroll through this text. Type \\<help-map>\\[help-quit] to exit the Help command.)
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a PATTERN Show commands whose name matches the PATTERN (a list of words
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or a regexp). See also the `apropos' command.
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b Display all key bindings.
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c KEYS Display the command name run by the given key sequence.
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C CODING Describe the given coding system, or RET for current ones.
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d PATTERN Show a list of functions, variables, and other items whose
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documentation matches the PATTERN (a list of words or a regexp).
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e Go to the *Messages* buffer which logs echo-area messages.
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f FUNCTION Display documentation for the given function.
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F COMMAND Show the Emacs manual's section that describes the command.
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g Display information about the GNU project.
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h Display the HELLO file which illustrates various scripts.
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i Start the Info documentation reader: read included manuals.
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I METHOD Describe a specific input method, or RET for current.
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k KEYS Display the full documentation for the key sequence.
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K KEYS Show the Emacs manual's section for the command bound to KEYS.
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l Show last 300 input keystrokes (lossage).
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L LANG-ENV Describes a specific language environment, or RET for current.
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m Display documentation of current minor modes and current major mode,
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including their special commands.
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n Display news of recent Emacs changes.
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o SYMBOL Display the given function or variable's documentation and value.
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p TOPIC Find packages matching a given topic keyword.
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P PACKAGE Describe the given Emacs Lisp package.
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r Display the Emacs manual in Info mode.
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s Display contents of current syntax table, plus explanations.
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S SYMBOL Show the section for the given symbol in the Info manual
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for the programming language used in this buffer.
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t Start the Emacs learn-by-doing tutorial.
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v VARIABLE Display the given variable's documentation and value.
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w COMMAND Display which keystrokes invoke the given command (where-is).
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. Display any available local help at point in the echo area.
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C-a Information about Emacs.
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C-c Emacs copying permission (GNU General Public License).
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C-d Instructions for debugging GNU Emacs.
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C-e External packages and information about Emacs.
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C-f Emacs FAQ.
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C-m How to order printed Emacs manuals.
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C-n News of recent Emacs changes.
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C-o Emacs ordering and distribution information.
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C-p Info about known Emacs problems.
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C-s Search forward \"help window\".
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C-t Emacs TODO list.
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C-w Information on absence of warranty for GNU Emacs."
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help-map)
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(defun function-called-at-point ()
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"Return a function around point or else called by the list containing point.
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If that doesn't give a function, return nil."
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(with-syntax-table emacs-lisp-mode-syntax-table
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(or (condition-case ()
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(save-excursion
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(or (not (zerop (skip-syntax-backward "_w")))
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(eq (char-syntax (following-char)) ?w)
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(eq (char-syntax (following-char)) ?_)
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(forward-sexp -1))
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(skip-chars-forward "'")
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(let ((obj (read (current-buffer))))
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(and (symbolp obj) (fboundp obj) obj)))
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(error nil))
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(condition-case ()
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(save-excursion
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(save-restriction
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(let ((forward-sexp-function nil)) ;Use elisp-mode's value
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(narrow-to-region (max (point-min)
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(- (point) 1000))
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(point-max))
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;; Move up to surrounding paren, then after the open.
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(backward-up-list 1)
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(forward-char 1)
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;; If there is space here, this is probably something
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;; other than a real Lisp function call, so ignore it.
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(if (looking-at "[ \t]")
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(error "Probably not a Lisp function call"))
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(let ((obj (read (current-buffer))))
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(and (symbolp obj) (fboundp obj) obj)))))
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(error nil))
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(let* ((str (find-tag-default))
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(sym (if str (intern-soft str))))
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(if (and sym (fboundp sym))
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sym
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(save-match-data
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(when (and str (string-match "\\`\\W*\\(.*?\\)\\W*\\'" str))
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(setq sym (intern-soft (match-string 1 str)))
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(and (fboundp sym) sym))))))))
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;;; `User' help functions
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(defun view-help-file (file &optional dir)
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(view-file (expand-file-name file (or dir data-directory)))
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(goto-address-mode 1)
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(goto-char (point-min)))
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(defun describe-distribution ()
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"Display info on how to obtain the latest version of GNU Emacs."
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(interactive)
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(view-help-file "DISTRIB"))
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(defun describe-copying ()
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"Display info on how you may redistribute copies of GNU Emacs."
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(interactive)
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(view-help-file "COPYING"))
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;; Maybe this command should just be removed.
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(defun describe-gnu-project ()
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"Browse online information on the GNU project."
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(interactive)
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(browse-url "https://www.gnu.org/gnu/thegnuproject.html"))
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(defun describe-no-warranty ()
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"Display info on all the kinds of warranty Emacs does NOT have."
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(interactive)
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(describe-copying)
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(let (case-fold-search)
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(search-forward "Disclaimer of Warranty")
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(forward-line 0)
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(recenter 0)))
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(defun describe-prefix-bindings ()
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"Describe the bindings of the prefix used to reach this command.
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The prefix described consists of all but the last event
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of the key sequence that ran this command."
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(interactive)
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(let ((key (this-command-keys)))
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(describe-bindings
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(if (stringp key)
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(substring key 0 (1- (length key)))
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(let ((prefix (make-vector (1- (length key)) nil))
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(i 0))
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(while (< i (length prefix))
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(aset prefix i (aref key i))
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(setq i (1+ i)))
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prefix)))))
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;; Make C-h after a prefix, when not specifically bound,
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;; run describe-prefix-bindings.
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(setq prefix-help-command 'describe-prefix-bindings)
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(defun view-emacs-news (&optional version)
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"Display info on recent changes to Emacs.
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With argument, display info only for the selected version."
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(interactive "P")
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(unless version
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(setq version emacs-major-version))
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(when (consp version)
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(let* ((all-versions
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(let (res)
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(mapc
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(lambda (file)
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(with-temp-buffer
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(insert-file-contents
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(expand-file-name file data-directory))
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(while (re-search-forward
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(if (member file '("NEWS.18" "NEWS.1-17"))
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"Changes in \\(?:Emacs\\|version\\)?[ \t]*\\([0-9]+\\(?:\\.[0-9]+\\)?\\)"
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"^\\* [^0-9\n]*\\([0-9]+\\.[0-9]+\\)") nil t)
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(setq res (cons (match-string-no-properties 1) res)))))
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(cons "NEWS"
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(directory-files data-directory nil
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"\\`NEWS\\.[0-9][-0-9]*\\'" nil)))
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(sort (delete-dups res) #'string>)))
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(current (car all-versions)))
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(setq version (completing-read
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(format "Read NEWS for the version (default %s): " current)
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all-versions nil nil nil nil current))
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(if (integerp (string-to-number version))
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(setq version (string-to-number version))
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(unless (or (member version all-versions)
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(<= (string-to-number version) (string-to-number current)))
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(error "No news about version %s" version)))))
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||
(when (integerp version)
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(cond ((<= version 12)
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(setq version (format "1.%d" version)))
|
||
((<= version 18)
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||
(setq version (format "%d" version)))
|
||
((> version emacs-major-version)
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||
(error "No news about Emacs %d (yet)" version))))
|
||
(let* ((vn (if (stringp version)
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||
(string-to-number version)
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||
version))
|
||
(file (cond
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||
((>= vn emacs-major-version) "NEWS")
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((< vn 18) "NEWS.1-17")
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(t (format "NEWS.%d" vn))))
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||
res)
|
||
(view-file (expand-file-name file data-directory))
|
||
(widen)
|
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(goto-char (point-min))
|
||
(when (stringp version)
|
||
(when (re-search-forward
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(concat (if (< vn 19)
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"Changes in Emacs[ \t]*"
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||
"^\\* [^0-9\n]*") version "$")
|
||
nil t)
|
||
(beginning-of-line)
|
||
(narrow-to-region
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||
(point)
|
||
(save-excursion
|
||
(while (and (setq res
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||
(re-search-forward
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||
(if (< vn 19)
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||
"Changes in \\(?:Emacs\\|version\\)?[ \t]*\\([0-9]+\\(?:\\.[0-9]+\\)?\\)"
|
||
"^\\* [^0-9\n]*\\([0-9]+\\.[0-9]+\\)") nil t))
|
||
(equal (match-string-no-properties 1) version)))
|
||
(or res (goto-char (point-max)))
|
||
(beginning-of-line)
|
||
(point)))))))
|
||
|
||
(defun view-emacs-todo (&optional _arg)
|
||
"Display the Emacs TODO list."
|
||
(interactive "P")
|
||
(view-help-file "TODO"))
|
||
|
||
(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)
|
||
(with-current-buffer (messages-buffer)
|
||
(goto-char (point-max))
|
||
(let ((win (display-buffer (current-buffer))))
|
||
;; If the buffer is already displayed, we need to forcibly set
|
||
;; the window point to scroll to the end of the buffer.
|
||
(set-window-point win (point))
|
||
win)))
|
||
|
||
(defun view-order-manuals ()
|
||
"Display information on how to buy printed copies of Emacs manuals."
|
||
(interactive)
|
||
(info "(emacs)Printed Books"))
|
||
|
||
(defun view-emacs-FAQ ()
|
||
"Display the Emacs Frequently Asked Questions (FAQ) file."
|
||
(interactive)
|
||
(info "(efaq)"))
|
||
|
||
(defun view-emacs-problems ()
|
||
"Display info on known problems with Emacs and possible workarounds."
|
||
(interactive)
|
||
(view-help-file "PROBLEMS"))
|
||
|
||
(defun view-emacs-debugging ()
|
||
"Display info on how to debug Emacs problems."
|
||
(interactive)
|
||
(view-help-file "DEBUG"))
|
||
|
||
;; This used to visit a plain text file etc/MORE.STUFF;
|
||
;; maybe this command should just be removed.
|
||
(defun view-external-packages ()
|
||
"Display info on where to get more Emacs packages."
|
||
(interactive)
|
||
(info "(efaq)Packages that do not come with Emacs"))
|
||
|
||
(defun view-lossage ()
|
||
"Display last few input keystrokes and the commands run.
|
||
For convenience this uses the same format as
|
||
`edit-last-kbd-macro'.
|
||
|
||
To record all your input, use `open-dribble-file'."
|
||
(interactive)
|
||
(help-setup-xref (list #'view-lossage)
|
||
(called-interactively-p 'interactive))
|
||
(with-help-window (help-buffer)
|
||
(princ " ")
|
||
(princ (mapconcat (lambda (key)
|
||
(cond
|
||
((and (consp key) (null (car key)))
|
||
(format ";; %s\n" (if (symbolp (cdr key)) (cdr key)
|
||
"anonymous-command")))
|
||
((or (integerp key) (symbolp key) (listp key))
|
||
(single-key-description key))
|
||
(t
|
||
(prin1-to-string key nil))))
|
||
(recent-keys 'include-cmds)
|
||
" "))
|
||
(with-current-buffer standard-output
|
||
(goto-char (point-min))
|
||
(let ((comment-start ";; ")
|
||
(comment-column 24))
|
||
(while (not (eobp))
|
||
(comment-indent)
|
||
(forward-line 1)))
|
||
;; Show point near the end of "lossage", as we did in Emacs 24.
|
||
(set-marker help-window-point-marker (point)))))
|
||
|
||
|
||
;; Key bindings
|
||
|
||
(defun describe-bindings (&optional prefix buffer)
|
||
"Display a buffer showing a list of all defined keys, and their definitions.
|
||
The keys are displayed in order of precedence.
|
||
|
||
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). BUFFER can be a buffer
|
||
or a buffer name."
|
||
(interactive)
|
||
(or buffer (setq buffer (current-buffer)))
|
||
(help-setup-xref (list #'describe-bindings prefix buffer)
|
||
(called-interactively-p 'interactive))
|
||
(with-help-window (help-buffer)
|
||
;; Be aware that `describe-buffer-bindings' puts its output into
|
||
;; the current buffer.
|
||
(with-current-buffer (help-buffer)
|
||
(describe-buffer-bindings buffer 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."
|
||
(declare (obsolete describe-buffer-bindings "24.4"))
|
||
(let ((buf (current-buffer)))
|
||
(with-help-window (help-buffer)
|
||
;; Be aware that `describe-buffer-bindings' puts its output into
|
||
;; the current buffer.
|
||
(with-current-buffer (help-buffer)
|
||
(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 nil nil
|
||
(and fn (symbol-name fn))))
|
||
(list (unless (equal val "") (intern val))
|
||
current-prefix-arg)))
|
||
(unless definition (error "No command"))
|
||
(let ((func (indirect-function definition))
|
||
(defs nil)
|
||
(standard-output (if insert (current-buffer) standard-output)))
|
||
;; In DEFS, find all symbols that are aliases for DEFINITION.
|
||
(mapatoms (lambda (symbol)
|
||
(and (fboundp symbol)
|
||
(not (eq symbol definition))
|
||
(eq func (condition-case ()
|
||
(indirect-function symbol)
|
||
(error symbol)))
|
||
(push symbol defs))))
|
||
;; Look at all the symbols--first DEFINITION,
|
||
;; then its aliases.
|
||
(dolist (symbol (cons definition defs))
|
||
(let* ((remapped (command-remapping symbol))
|
||
(keys (where-is-internal
|
||
symbol overriding-local-map nil nil remapped))
|
||
(keys (mapconcat 'key-description keys ", "))
|
||
string)
|
||
(setq string
|
||
(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"
|
||
symbol remapped keys)
|
||
(format "%s is on %s" symbol keys))
|
||
;; If this is the command the user asked about,
|
||
;; and it is not on any key, say so.
|
||
;; For other symbols, its aliases, say nothing
|
||
;; about them unless they are on keys.
|
||
(if (eq symbol definition)
|
||
(format "%s is not on any key" symbol)))))
|
||
(when string
|
||
(unless (eq symbol definition)
|
||
(princ ";\n its alias "))
|
||
(princ string)))))
|
||
nil)
|
||
|
||
(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 help--binding-undefined-p (defn)
|
||
(or (null defn) (integerp defn) (equal defn 'undefined)))
|
||
|
||
(defun help--analyze-key (key untranslated)
|
||
"Get information about KEY its corresponding UNTRANSLATED events.
|
||
Returns a list of the form (BRIEF-DESC DEFN EVENT MOUSE-MSG)."
|
||
(if (numberp untranslated)
|
||
(error "Missing `untranslated'!"))
|
||
(let* ((event (when (> (length key) 0)
|
||
(aref key (if (and (symbolp (aref key 0))
|
||
(> (length key) 1)
|
||
(consp (aref key 1)))
|
||
;; Look at the second event when the first
|
||
;; is a pseudo-event like `mode-line' or
|
||
;; `left-fringe'.
|
||
1
|
||
0))))
|
||
(modifiers (event-modifiers event))
|
||
(mouse-msg (if (or (memq 'click modifiers) (memq 'down modifiers)
|
||
(memq 'drag modifiers))
|
||
" at that spot" ""))
|
||
(defn (key-binding key t)))
|
||
;; Handle the case where we faked an entry in "Select and Paste" menu.
|
||
(when (and (eq defn nil)
|
||
(stringp (aref key (1- (length key))))
|
||
(eq (key-binding (substring key 0 -1)) 'yank-menu))
|
||
(setq defn 'menu-bar-select-yank))
|
||
;; Don't bother user with strings from (e.g.) the select-paste menu.
|
||
(when (stringp (aref key (1- (length key))))
|
||
(aset key (1- (length key)) "(any string)"))
|
||
(when (and untranslated
|
||
(stringp (aref untranslated (1- (length untranslated)))))
|
||
(aset untranslated (1- (length untranslated)) "(any string)"))
|
||
(list
|
||
;; Now describe the key, perhaps as changed.
|
||
(let ((key-desc (help-key-description key untranslated)))
|
||
(if (help--binding-undefined-p defn)
|
||
(format "%s%s is undefined" key-desc mouse-msg)
|
||
(format "%s%s runs the command %S" key-desc mouse-msg defn)))
|
||
defn event mouse-msg)))
|
||
|
||
(defun help--filter-info-list (info-list i)
|
||
"Drop the undefined keys."
|
||
(or
|
||
;; Remove all `undefined' keys.
|
||
(delq nil (mapcar (lambda (x)
|
||
(unless (help--binding-undefined-p (nth i x)) x))
|
||
info-list))
|
||
;; If nothing left, then keep one (the last one).
|
||
(last info-list)))
|
||
|
||
(defun describe-key-briefly (&optional key-list insert untranslated)
|
||
"Print the name of the functions KEY-LIST invokes.
|
||
KEY-LIST is a list of pairs (SEQ . RAW-SEQ) of key sequences, where
|
||
RAW-SEQ is the untranslated form of the key sequence SEQ.
|
||
If INSERT (the prefix arg) is non-nil, insert the message in the buffer.
|
||
|
||
While reading KEY-LIST interactively, this command temporarily enables
|
||
menu items or tool-bar buttons that are disabled to allow getting help
|
||
on them."
|
||
(declare (advertised-calling-convention (key-list &optional insert) "27.1"))
|
||
(interactive
|
||
;; Ignore mouse movement events because it's too easy to miss the
|
||
;; message while moving the mouse.
|
||
(let ((key-list (help--read-key-sequence 'no-mouse-movement)))
|
||
`(,key-list ,current-prefix-arg)))
|
||
(when (arrayp key-list)
|
||
;; Old calling convention, changed
|
||
(setq key-list (list (cons key-list
|
||
(if (numberp untranslated)
|
||
(this-single-command-raw-keys)
|
||
untranslated)))))
|
||
(let* ((info-list (mapcar (lambda (kr)
|
||
(help--analyze-key (car kr) (cdr kr)))
|
||
key-list))
|
||
(msg (mapconcat #'car (help--filter-info-list info-list 1) "\n")))
|
||
(if insert (insert msg) (message "%s" msg))))
|
||
|
||
(defun help--key-binding-keymap (key &optional accept-default no-remap position)
|
||
"Return a keymap holding a binding for KEY within current keymaps.
|
||
The effect of the arguments KEY, ACCEPT-DEFAULT, NO-REMAP and
|
||
POSITION is as documented in the function `key-binding'."
|
||
(let* ((active-maps (current-active-maps t position))
|
||
map found)
|
||
;; We loop over active maps like key-binding does.
|
||
(while (and
|
||
(not found)
|
||
(setq map (pop active-maps)))
|
||
(setq found (lookup-key map key accept-default))
|
||
(when (integerp found)
|
||
;; The first `found' characters of KEY were found but not the
|
||
;; whole sequence.
|
||
(setq found nil)))
|
||
(when found
|
||
(if (and (symbolp found)
|
||
(not no-remap)
|
||
(command-remapping found))
|
||
;; The user might want to know in which map the binding is
|
||
;; found, or in which map the remapping is found. The
|
||
;; default is to show the latter.
|
||
(help--key-binding-keymap (vector 'remap found))
|
||
map))))
|
||
|
||
(defun help--binding-locus (key position)
|
||
"Describe in which keymap KEY is defined.
|
||
Return a symbol pointing to that keymap if one exists ; otherwise
|
||
return nil. The argument POSITION is as documented in the
|
||
function `key-binding'."
|
||
(let ((map (help--key-binding-keymap key t nil position)))
|
||
(when map
|
||
(catch 'found
|
||
(let ((advertised-syms (nconc
|
||
(list 'overriding-terminal-local-map
|
||
'overriding-local-map)
|
||
(delq nil
|
||
(mapcar
|
||
(lambda (mode-and-map)
|
||
(let ((mode (car mode-and-map)))
|
||
(when (symbol-value mode)
|
||
(intern-soft
|
||
(format "%s-map" mode)))))
|
||
minor-mode-map-alist))
|
||
(list 'global-map
|
||
(intern-soft (format "%s-map" major-mode))))))
|
||
;; Look into these advertised symbols first.
|
||
(dolist (sym advertised-syms)
|
||
(when (and
|
||
(boundp sym)
|
||
(eq map (symbol-value sym)))
|
||
(throw 'found sym)))
|
||
;; Only look in other symbols otherwise.
|
||
(mapatoms
|
||
(lambda (x)
|
||
(when (and (boundp x)
|
||
;; Avoid let-bound symbols.
|
||
(special-variable-p x)
|
||
(eq (symbol-value x) map))
|
||
(throw 'found x))))
|
||
nil)))))
|
||
|
||
(defun help--read-key-sequence (&optional no-mouse-movement)
|
||
"Read a key sequence from the user.
|
||
Usually reads a single key sequence, except when that sequence might
|
||
hide another one (e.g. a down event, where the user is interested
|
||
in getting info about the up event, or a click event, where the user
|
||
wants to get info about the double click).
|
||
Return a list of elements of the form (SEQ . RAW-SEQ), where SEQ is a key
|
||
sequence, and RAW-SEQ is its untranslated form.
|
||
If NO-MOUSE-MOVEMENT is non-nil, ignore key sequences starting
|
||
with `mouse-movement' events."
|
||
(let ((enable-disabled-menus-and-buttons t)
|
||
(cursor-in-echo-area t)
|
||
(side-event nil)
|
||
saved-yank-menu)
|
||
(unwind-protect
|
||
(let (last-modifiers key-list)
|
||
;; If yank-menu is empty, populate it temporarily, so that
|
||
;; "Select and Paste" menu can generate a complete event.
|
||
(when (null (cdr yank-menu))
|
||
(setq saved-yank-menu (copy-sequence yank-menu))
|
||
(menu-bar-update-yank-menu "(any string)" nil))
|
||
(while
|
||
;; Read at least one key-sequence.
|
||
(or (null key-list)
|
||
;; After a down event, also read the (presumably) following
|
||
;; up-event.
|
||
(memq 'down last-modifiers)
|
||
;; After a click, see if a double click is on the way.
|
||
(and (memq 'click last-modifiers)
|
||
(not (sit-for (/ double-click-time 1000.0) t))))
|
||
(let* ((seq (read-key-sequence "\
|
||
Describe the following key, mouse click, or menu item: "
|
||
nil nil 'can-return-switch-frame))
|
||
(raw-seq (this-single-command-raw-keys))
|
||
(keyn (when (> (length seq) 0)
|
||
(aref seq (1- (length seq)))))
|
||
(base (event-basic-type keyn))
|
||
(modifiers (event-modifiers keyn)))
|
||
(cond
|
||
((zerop (length seq))) ;FIXME: Can this happen?
|
||
((and no-mouse-movement (eq base 'mouse-movement)) nil)
|
||
((memq base '(mouse-movement switch-frame select-window))
|
||
;; Mostly ignore these events since it's sometimes difficult to
|
||
;; generate the event you care about without also generating
|
||
;; these side-events along the way.
|
||
(setq side-event (cons seq raw-seq)))
|
||
((eq base 'help-echo) nil)
|
||
(t
|
||
(setq last-modifiers modifiers)
|
||
(push (cons seq raw-seq) key-list)))))
|
||
(if side-event
|
||
(cons side-event (nreverse key-list))
|
||
(nreverse key-list)))
|
||
;; Put yank-menu back as it was, if we changed it.
|
||
(when saved-yank-menu
|
||
(setq yank-menu (copy-sequence saved-yank-menu))
|
||
(fset 'yank-menu (cons 'keymap yank-menu))))))
|
||
|
||
(defun describe-key (&optional key-list buffer up-event)
|
||
"Display documentation of the function invoked by KEY-LIST.
|
||
KEY-LIST can be any kind of a key sequence; it can include keyboard events,
|
||
mouse events, and/or menu events. When calling from a program,
|
||
pass KEY-LIST as a list of elements (SEQ . RAW-SEQ) where SEQ is
|
||
a key-sequence and RAW-SEQ is its untranslated form.
|
||
|
||
While reading KEY-LIST interactively, this command temporarily enables
|
||
menu items or tool-bar buttons that are disabled to allow getting help
|
||
on them.
|
||
|
||
BUFFER is the buffer in which to lookup those keys; it defaults to the
|
||
current buffer."
|
||
(declare (advertised-calling-convention (key-list &optional buffer) "27.1"))
|
||
(interactive (list (help--read-key-sequence)))
|
||
(when (arrayp key-list)
|
||
;; Compatibility with old calling convention.
|
||
(setq key-list (cons (list key-list) (if up-event (list up-event))))
|
||
(when buffer
|
||
(let ((raw (if (numberp buffer) (this-single-command-raw-keys) buffer)))
|
||
(setf (cdar (last key-list)) raw)))
|
||
(setq buffer nil))
|
||
(let* ((buf (or buffer (current-buffer)))
|
||
(on-link
|
||
(mapcar (lambda (kr)
|
||
(let ((raw (cdr kr)))
|
||
(and (not (memq mouse-1-click-follows-link '(nil double)))
|
||
(> (length raw) 0)
|
||
(eq (car-safe (aref raw 0)) 'mouse-1)
|
||
(with-current-buffer buf
|
||
(mouse-on-link-p (event-start (aref raw 0)))))))
|
||
key-list))
|
||
(info-list
|
||
(help--filter-info-list
|
||
(with-current-buffer buf
|
||
(mapcar (lambda (x)
|
||
(pcase-let* ((`(,seq . ,raw-seq) x)
|
||
(`(,brief-desc ,defn ,event ,_mouse-msg)
|
||
(help--analyze-key seq raw-seq))
|
||
(locus
|
||
(help--binding-locus
|
||
seq (event-start event))))
|
||
`(,seq ,brief-desc ,defn ,locus)))
|
||
key-list))
|
||
2)))
|
||
(help-setup-xref (list (lambda (key-list buf)
|
||
(describe-key key-list
|
||
(if (buffer-live-p buf) buf)))
|
||
key-list buf)
|
||
(called-interactively-p 'interactive))
|
||
(if (and (<= (length info-list) 1)
|
||
(help--binding-undefined-p (nth 2 (car info-list))))
|
||
(message "%s" (nth 1 (car info-list)))
|
||
(with-help-window (help-buffer)
|
||
(when (> (length info-list) 1)
|
||
;; FIXME: Make this into clickable hyperlinks.
|
||
(princ "There were several key-sequences:\n\n")
|
||
(princ (mapconcat (lambda (info)
|
||
(pcase-let ((`(,_seq ,brief-desc ,_defn ,_locus)
|
||
info))
|
||
(concat " " brief-desc)))
|
||
info-list
|
||
"\n"))
|
||
(when (delq nil on-link)
|
||
(princ "\n\nThose are influenced by `mouse-1-click-follows-link'"))
|
||
(princ "\n\nThey're all described below."))
|
||
(pcase-dolist (`(,_seq ,brief-desc ,defn ,locus)
|
||
info-list)
|
||
(when defn
|
||
(when (> (length info-list) 1)
|
||
(with-current-buffer standard-output
|
||
(insert "\n\n"
|
||
;; FIXME: Can't use eval-when-compile because purified
|
||
;; strings lose their text properties :-(
|
||
(propertize "\n" 'face
|
||
'(:height 0.1 :inverse-video t :extend t))
|
||
"\n")))
|
||
|
||
(princ brief-desc)
|
||
(when locus
|
||
(princ (format " (found in %s)" locus)))
|
||
(princ ", which is ")
|
||
(describe-function-1 defn)))))))
|
||
|
||
(defun search-forward-help-for-help ()
|
||
"Search forward \"help window\"."
|
||
(interactive)
|
||
;; Move cursor to the "help window".
|
||
(pop-to-buffer " *Metahelp*")
|
||
;; Do incremental search forward.
|
||
(isearch-forward nil t))
|
||
|
||
(defun describe-minor-mode (minor-mode)
|
||
"Display documentation of a minor mode given as MINOR-MODE.
|
||
MINOR-MODE can be a minor mode symbol or a minor mode indicator string
|
||
appeared on the mode-line."
|
||
(interactive (list (completing-read
|
||
"Minor mode: "
|
||
(nconc
|
||
(describe-minor-mode-completion-table-for-symbol)
|
||
(describe-minor-mode-completion-table-for-indicator)
|
||
))))
|
||
(if (symbolp minor-mode)
|
||
(setq minor-mode (symbol-name minor-mode)))
|
||
(let ((symbols (describe-minor-mode-completion-table-for-symbol))
|
||
(indicators (describe-minor-mode-completion-table-for-indicator)))
|
||
(cond
|
||
((member minor-mode symbols)
|
||
(describe-minor-mode-from-symbol (intern minor-mode)))
|
||
((member minor-mode indicators)
|
||
(describe-minor-mode-from-indicator minor-mode))
|
||
(t
|
||
(error "No such minor mode: %s" minor-mode)))))
|
||
|
||
;; symbol
|
||
(defun describe-minor-mode-completion-table-for-symbol ()
|
||
;; In order to list up all minor modes, minor-mode-list
|
||
;; is used here instead of minor-mode-alist.
|
||
(delq nil (mapcar 'symbol-name minor-mode-list)))
|
||
|
||
(defun describe-minor-mode-from-symbol (symbol)
|
||
"Display documentation of a minor mode given as a symbol, SYMBOL."
|
||
(interactive (list (intern (completing-read
|
||
"Minor mode symbol: "
|
||
(describe-minor-mode-completion-table-for-symbol)))))
|
||
(if (fboundp symbol)
|
||
(describe-function symbol)
|
||
(describe-variable symbol)))
|
||
|
||
;; indicator
|
||
(defun describe-minor-mode-completion-table-for-indicator ()
|
||
(delq nil
|
||
(mapcar (lambda (x)
|
||
(let ((i (format-mode-line x)))
|
||
;; remove first space if existed
|
||
(cond
|
||
((= 0 (length i))
|
||
nil)
|
||
((eq (aref i 0) ?\s)
|
||
(substring i 1))
|
||
(t
|
||
i))))
|
||
minor-mode-alist)))
|
||
|
||
(defun describe-minor-mode-from-indicator (indicator)
|
||
"Display documentation of a minor mode specified by INDICATOR.
|
||
If you call this function interactively, you can give indicator which
|
||
is currently activated with completion."
|
||
(interactive (list
|
||
(completing-read
|
||
"Minor mode indicator: "
|
||
(describe-minor-mode-completion-table-for-indicator))))
|
||
(let ((minor-mode (lookup-minor-mode-from-indicator indicator)))
|
||
(if minor-mode
|
||
(describe-minor-mode-from-symbol minor-mode)
|
||
(error "Cannot find minor mode for `%s'" indicator))))
|
||
|
||
(defun lookup-minor-mode-from-indicator (indicator)
|
||
"Return a minor mode symbol from its indicator on the mode line."
|
||
;; remove first space if existed
|
||
(if (and (< 0 (length indicator))
|
||
(eq (aref indicator 0) ?\s))
|
||
(setq indicator (substring indicator 1)))
|
||
(let ((minor-modes minor-mode-alist)
|
||
result)
|
||
(while minor-modes
|
||
(let* ((minor-mode (car (car minor-modes)))
|
||
(anindicator (format-mode-line
|
||
(car (cdr (car minor-modes))))))
|
||
;; remove first space if existed
|
||
(if (and (stringp anindicator)
|
||
(> (length anindicator) 0)
|
||
(eq (aref anindicator 0) ?\s))
|
||
(setq anindicator (substring anindicator 1)))
|
||
(if (equal indicator anindicator)
|
||
(setq result minor-mode
|
||
minor-modes nil)
|
||
(setq minor-modes (cdr minor-modes)))))
|
||
result))
|
||
|
||
(declare-function x-display-pixel-height "xfns.c" (&optional terminal))
|
||
(declare-function x-display-pixel-width "xfns.c" (&optional terminal))
|
||
|
||
;;; Automatic resizing of temporary buffers.
|
||
(defcustom temp-buffer-max-height
|
||
(lambda (_buffer)
|
||
(if (and (display-graphic-p) (eq (selected-window) (frame-root-window)))
|
||
(/ (x-display-pixel-height) (frame-char-height) 2)
|
||
(/ (- (frame-height) 2) 2)))
|
||
"Maximum height of a window displaying a temporary buffer.
|
||
This is effective only when Temp Buffer Resize mode is enabled.
|
||
The value is the maximum height (in lines) which
|
||
`resize-temp-buffer-window' will give to a window displaying a
|
||
temporary buffer. It can also be a function to be called to
|
||
choose the height for such a buffer. It gets one argument, the
|
||
buffer, and should return a positive integer. At the time the
|
||
function is called, the window to be resized is selected."
|
||
:type '(choice integer function)
|
||
:group 'help
|
||
:version "24.3")
|
||
|
||
(defcustom temp-buffer-max-width
|
||
(lambda (_buffer)
|
||
(if (and (display-graphic-p) (eq (selected-window) (frame-root-window)))
|
||
(/ (x-display-pixel-width) (frame-char-width) 2)
|
||
(/ (- (frame-width) 2) 2)))
|
||
"Maximum width of a window displaying a temporary buffer.
|
||
This is effective only when Temp Buffer Resize mode is enabled.
|
||
The value is the maximum width (in columns) which
|
||
`resize-temp-buffer-window' will give to a window displaying a
|
||
temporary buffer. It can also be a function to be called to
|
||
choose the width for such a buffer. It gets one argument, the
|
||
buffer, and should return a positive integer. At the time the
|
||
function is called, the window to be resized is selected."
|
||
:type '(choice integer function)
|
||
:group 'help
|
||
:version "24.4")
|
||
|
||
(define-minor-mode temp-buffer-resize-mode
|
||
"Toggle auto-resizing temporary buffer windows (Temp Buffer Resize Mode).
|
||
|
||
When Temp Buffer Resize mode is enabled, the windows in which we
|
||
show a temporary buffer are automatically resized in height to
|
||
fit the buffer's contents, but never more than
|
||
`temp-buffer-max-height' nor less than `window-min-height'.
|
||
|
||
A window is resized only if it has been specially created for the
|
||
buffer. Windows that have shown another buffer before are not
|
||
resized. A frame is resized only if `fit-frame-to-buffer' is
|
||
non-nil.
|
||
|
||
This mode is used by `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 (&optional window)
|
||
"Resize WINDOW to fit its contents.
|
||
WINDOW must be a live window and defaults to the selected one.
|
||
Do not resize if WINDOW was not created by `display-buffer'.
|
||
|
||
If WINDOW is part of a vertical combination, restrain its new
|
||
size by `temp-buffer-max-height' and do not resize if its minimum
|
||
accessible position is scrolled out of view. If WINDOW is part
|
||
of a horizontal combination, restrain its new size by
|
||
`temp-buffer-max-width'. In both cases, the value of the option
|
||
`fit-window-to-buffer-horizontally' can inhibit resizing.
|
||
|
||
If WINDOW is the root window of its frame, resize the frame
|
||
provided `fit-frame-to-buffer' is non-nil.
|
||
|
||
This function may call `preserve-window-size' to preserve the
|
||
size of WINDOW."
|
||
(setq window (window-normalize-window window t))
|
||
(let ((height (if (functionp temp-buffer-max-height)
|
||
(with-selected-window window
|
||
(funcall temp-buffer-max-height (window-buffer)))
|
||
temp-buffer-max-height))
|
||
(width (if (functionp temp-buffer-max-width)
|
||
(with-selected-window window
|
||
(funcall temp-buffer-max-width (window-buffer)))
|
||
temp-buffer-max-width))
|
||
(quit-cadr (cadr (window-parameter window 'quit-restore))))
|
||
;; Resize WINDOW iff it was made by `display-buffer'.
|
||
(when (or (and (eq quit-cadr 'window)
|
||
(or (and (window-combined-p window)
|
||
(not (eq fit-window-to-buffer-horizontally
|
||
'only))
|
||
(pos-visible-in-window-p (point-min) window))
|
||
(and (window-combined-p window t)
|
||
fit-window-to-buffer-horizontally)))
|
||
(and (eq quit-cadr 'frame)
|
||
fit-frame-to-buffer
|
||
(eq window (frame-root-window window))))
|
||
(fit-window-to-buffer window height nil width nil t))))
|
||
|
||
;;; Help windows.
|
||
(defcustom help-window-select nil
|
||
"Non-nil means select help window for viewing.
|
||
Choices are:
|
||
|
||
never (nil) Select help window only if there is no other window
|
||
on its frame.
|
||
|
||
other Select help window if and only if it appears on the
|
||
previously selected frame, that frame contains at
|
||
least two other windows and the help window is
|
||
either new or showed a different buffer before.
|
||
|
||
always (t) Always select the help window.
|
||
|
||
If this option is non-nil and the help window appears on another
|
||
frame, then give that frame input focus too. Note also that if
|
||
the help window appears on another frame, it may get selected and
|
||
its frame get input focus even if this option is nil.
|
||
|
||
This option has effect if and only if the help window was created
|
||
by `with-help-window'."
|
||
:type '(choice (const :tag "never (nil)" nil)
|
||
(const :tag "other" other)
|
||
(const :tag "always (t)" t))
|
||
:group 'help
|
||
:version "23.1")
|
||
|
||
(define-obsolete-variable-alias 'help-enable-auto-load
|
||
'help-enable-autoload "27.1")
|
||
|
||
(defcustom help-enable-autoload t
|
||
"Whether Help commands can perform autoloading.
|
||
If non-nil, whenever \\[describe-function] is called for an
|
||
autoloaded function whose docstring contains any key substitution
|
||
construct (see `substitute-command-keys'), the library is loaded,
|
||
so that the documentation can show the right key bindings."
|
||
:type 'boolean
|
||
:group 'help
|
||
:version "24.3")
|
||
|
||
(defun help-window-display-message (quit-part window &optional scroll)
|
||
"Display message telling how to quit and scroll help window.
|
||
QUIT-PART is a string telling how to quit the help window WINDOW.
|
||
Optional argument SCROLL non-nil means tell how to scroll WINDOW.
|
||
SCROLL equal `other' means tell how to scroll the \"other\"
|
||
window."
|
||
(let ((scroll-part
|
||
(cond
|
||
;; If we don't have QUIT-PART we probably reuse a window
|
||
;; showing the same buffer so we don't show any message.
|
||
((not quit-part) nil)
|
||
((pos-visible-in-window-p
|
||
(with-current-buffer (window-buffer window)
|
||
(point-max)) window t)
|
||
;; Buffer end is at least partially visible, no need to talk
|
||
;; about scrolling.
|
||
".")
|
||
((eq scroll 'other)
|
||
", \\[scroll-other-window] to scroll help.")
|
||
(scroll ", \\[scroll-up] to scroll help."))))
|
||
(message "%s"
|
||
(substitute-command-keys (concat quit-part scroll-part)))))
|
||
|
||
(defun help-window-setup (window &optional value)
|
||
"Set up help window WINDOW for `with-help-window'.
|
||
WINDOW is the window used for displaying the help buffer.
|
||
Return VALUE."
|
||
(let* ((help-buffer (when (window-live-p window)
|
||
(window-buffer window)))
|
||
(help-setup (when (window-live-p window)
|
||
(car (window-parameter window 'quit-restore))))
|
||
(frame (window-frame window)))
|
||
|
||
(when help-buffer
|
||
;; Handle `help-window-point-marker'.
|
||
(when (eq (marker-buffer help-window-point-marker) help-buffer)
|
||
(set-window-point window help-window-point-marker)
|
||
;; Reset `help-window-point-marker'.
|
||
(set-marker help-window-point-marker nil))
|
||
|
||
;; If the help window appears on another frame, select it if
|
||
;; `help-window-select' is non-nil and give that frame input focus
|
||
;; too. See also Bug#19012.
|
||
(when (and help-window-select
|
||
(frame-live-p help-window-old-frame)
|
||
(not (eq frame help-window-old-frame)))
|
||
(select-window window)
|
||
(select-frame-set-input-focus frame))
|
||
|
||
(cond
|
||
((or (eq window (selected-window))
|
||
;; If the help window is on the selected frame, select
|
||
;; it if `help-window-select' is t or `help-window-select'
|
||
;; is 'other, the frame contains at least three windows, and
|
||
;; the help window did show another buffer before. See also
|
||
;; Bug#11039.
|
||
(and (eq frame (selected-frame))
|
||
(or (eq help-window-select t)
|
||
(and (eq help-window-select 'other)
|
||
(> (length (window-list nil 'no-mini)) 2)
|
||
(not (eq help-setup 'same))))
|
||
(select-window window)))
|
||
;; The help window is or gets selected ...
|
||
(help-window-display-message
|
||
(cond
|
||
((eq help-setup 'window)
|
||
;; ... and is new, ...
|
||
"Type \"q\" to delete help window")
|
||
((eq help-setup 'frame)
|
||
;; ... on a new frame, ...
|
||
"Type \"q\" to quit the help frame")
|
||
((eq help-setup 'other)
|
||
;; ... or displayed some other buffer before.
|
||
"Type \"q\" to restore previous buffer"))
|
||
window t))
|
||
((and (eq (window-frame window) help-window-old-frame)
|
||
(= (length (window-list nil 'no-mini)) 2))
|
||
;; There are two windows on the help window's frame and the
|
||
;; other one is the selected one.
|
||
(help-window-display-message
|
||
(cond
|
||
((eq help-setup 'window)
|
||
"Type \\[delete-other-windows] to delete the help window")
|
||
((eq help-setup 'other)
|
||
"Type \"q\" in help window to restore its previous buffer"))
|
||
window 'other))
|
||
(t
|
||
;; The help window is not selected ...
|
||
(help-window-display-message
|
||
(cond
|
||
((eq help-setup 'window)
|
||
;; ... and is new, ...
|
||
"Type \"q\" in help window to delete it")
|
||
((eq help-setup 'other)
|
||
;; ... or displayed some other buffer before.
|
||
"Type \"q\" in help window to restore previous buffer"))
|
||
window))))
|
||
;; Return VALUE.
|
||
value))
|
||
|
||
;; `with-help-window' is a wrapper for `with-temp-buffer-window'
|
||
;; providing the following additional twists:
|
||
|
||
;; (1) It puts the buffer in `help-mode' (via `help-mode-setup') and
|
||
;; adds cross references (via `help-mode-finish').
|
||
|
||
;; (2) It issues a message telling how to scroll and quit the help
|
||
;; window (via `help-window-setup').
|
||
|
||
;; (3) An option (customizable via `help-window-select') to select the
|
||
;; help window automatically.
|
||
|
||
;; (4) A marker (`help-window-point-marker') to move point in the help
|
||
;; window to an arbitrary buffer position.
|
||
(defmacro with-help-window (buffer-or-name &rest body)
|
||
"Evaluate BODY, send output to BUFFER-OR-NAME and show in a help window.
|
||
This construct is like `with-temp-buffer-window' but unlike that
|
||
puts the buffer specified by BUFFER-OR-NAME in `help-mode' and
|
||
displays a message about how to delete the help window when it's no
|
||
longer needed. The help window will be selected if
|
||
`help-window-select' is non-nil.
|
||
Most of this is done by `help-window-setup', which see."
|
||
(declare (indent 1) (debug t))
|
||
`(progn
|
||
;; Make `help-window-point-marker' point nowhere. The only place
|
||
;; where this should be set to a buffer position is within BODY.
|
||
(set-marker help-window-point-marker nil)
|
||
(let ((temp-buffer-window-setup-hook
|
||
(cons 'help-mode-setup temp-buffer-window-setup-hook))
|
||
(temp-buffer-window-show-hook
|
||
(cons 'help-mode-finish temp-buffer-window-show-hook)))
|
||
(setq help-window-old-frame (selected-frame))
|
||
(with-temp-buffer-window
|
||
,buffer-or-name nil 'help-window-setup (progn ,@body)))))
|
||
|
||
;; Called from C, on encountering `help-char' when reading a char.
|
||
;; Don't print to *Help*; that would clobber Help history.
|
||
(defun help-form-show ()
|
||
"Display the output of a non-nil `help-form'."
|
||
(let ((msg (eval help-form)))
|
||
(if (stringp msg)
|
||
(with-output-to-temp-buffer " *Char Help*"
|
||
(princ msg)))))
|
||
|
||
|
||
(defun help--docstring-quote (string)
|
||
"Return a doc string that represents STRING.
|
||
The result, when formatted by `substitute-command-keys', should equal STRING."
|
||
(replace-regexp-in-string "['\\`‘’]" "\\\\=\\&" string))
|
||
|
||
;; The following functions used to be in help-fns.el, which is not preloaded.
|
||
;; But for various reasons, they are more widely needed, so they were
|
||
;; moved to this file, which is preloaded. https://debbugs.gnu.org/17001
|
||
|
||
(defun help-split-fundoc (docstring def &optional section)
|
||
"Split a function DOCSTRING into the actual doc and the usage info.
|
||
Return (USAGE . DOC), where USAGE is a string describing the argument
|
||
list of DEF, such as \"(apply FUNCTION &rest ARGUMENTS)\".
|
||
DEF is the function whose usage we're looking for in DOCSTRING.
|
||
With SECTION nil, return nil if there is no usage info; conversely,
|
||
SECTION t means to return (USAGE . DOC) even if there's no usage info.
|
||
When SECTION is \\='usage or \\='doc, return only that part."
|
||
;; Functions can get the calling sequence at the end of the doc string.
|
||
;; In cases where `function' has been fset to a subr we can't search for
|
||
;; function's name in the doc string so we use `fn' as the anonymous
|
||
;; function name instead.
|
||
(let* ((found (and docstring
|
||
(string-match "\n\n(fn\\(\\( .*\\)?)\\)\\'" docstring)))
|
||
(doc (if found
|
||
(and (memq section '(t nil doc))
|
||
(not (zerop (match-beginning 0)))
|
||
(substring docstring 0 (match-beginning 0)))
|
||
docstring))
|
||
(usage (and found
|
||
(memq section '(t nil usage))
|
||
(let ((tail (match-string 1 docstring)))
|
||
(format "(%s%s"
|
||
;; Replace `fn' with the actual function name.
|
||
(if (and (symbolp def) def)
|
||
(help--docstring-quote (format "%S" def))
|
||
'anonymous)
|
||
tail)))))
|
||
(pcase section
|
||
(`nil (and usage (cons usage doc)))
|
||
(`t (cons usage doc))
|
||
(`usage usage)
|
||
(`doc doc))))
|
||
|
||
(defun help-add-fundoc-usage (docstring arglist)
|
||
"Add the usage info to DOCSTRING.
|
||
If DOCSTRING already has a usage info, then just return it unchanged.
|
||
The usage info is built from ARGLIST. DOCSTRING can be nil.
|
||
ARGLIST can also be t or a string of the form \"(FUN ARG1 ARG2 ...)\"."
|
||
(unless (stringp docstring) (setq docstring ""))
|
||
(if (or (string-match "\n\n(fn\\(\\( .*\\)?)\\)\\'" docstring)
|
||
(eq arglist t))
|
||
docstring
|
||
(concat docstring
|
||
(if (string-match "\n?\n\\'" docstring)
|
||
(if (< (- (match-end 0) (match-beginning 0)) 2) "\n" "")
|
||
"\n\n")
|
||
(if (stringp arglist)
|
||
(if (string-match "\\`[^ ]+\\(.*\\))\\'" arglist)
|
||
(concat "(fn" (match-string 1 arglist) ")")
|
||
(error "Unrecognized usage format"))
|
||
(help--make-usage-docstring 'fn arglist)))))
|
||
|
||
(defun help-function-arglist (def &optional preserve-names)
|
||
"Return a formal argument list for the function DEF.
|
||
If PRESERVE-NAMES is non-nil, return a formal arglist that uses
|
||
the same names as used in the original source code, when possible."
|
||
;; Handle symbols aliased to other symbols.
|
||
(if (and (symbolp def) (fboundp def)) (setq def (indirect-function def)))
|
||
;; Advice wrappers have "catch all" args, so fetch the actual underlying
|
||
;; function to find the real arguments.
|
||
(while (advice--p def) (setq def (advice--cdr def)))
|
||
;; If definition is a macro, find the function inside it.
|
||
(if (eq (car-safe def) 'macro) (setq def (cdr def)))
|
||
(cond
|
||
((and (byte-code-function-p def) (listp (aref def 0))) (aref def 0))
|
||
((eq (car-safe def) 'lambda) (nth 1 def))
|
||
((eq (car-safe def) 'closure) (nth 2 def))
|
||
((or (and (byte-code-function-p def) (integerp (aref def 0)))
|
||
(subrp def) (module-function-p def))
|
||
(or (when preserve-names
|
||
(let* ((doc (condition-case nil (documentation def) (error nil)))
|
||
(docargs (if doc (car (help-split-fundoc doc nil))))
|
||
(arglist (if docargs
|
||
(cdar (read-from-string (downcase docargs)))))
|
||
(valid t))
|
||
;; Check validity.
|
||
(dolist (arg arglist)
|
||
(unless (and (symbolp arg)
|
||
(let ((name (symbol-name arg)))
|
||
(if (eq (aref name 0) ?&)
|
||
(memq arg '(&rest &optional))
|
||
(not (string-match "\\." name)))))
|
||
(setq valid nil)))
|
||
(when valid arglist)))
|
||
(let* ((arity (func-arity def))
|
||
(max (cdr arity))
|
||
(min (car arity))
|
||
(arglist ()))
|
||
(dotimes (i min)
|
||
(push (intern (concat "arg" (number-to-string (1+ i)))) arglist))
|
||
(when (and (integerp max) (> max min))
|
||
(push '&optional arglist)
|
||
(dotimes (i (- max min))
|
||
(push (intern (concat "arg" (number-to-string (+ 1 i min))))
|
||
arglist)))
|
||
(unless (integerp max) (push '&rest arglist) (push 'rest arglist))
|
||
(nreverse arglist))))
|
||
((and (autoloadp def) (not (eq (nth 4 def) 'keymap)))
|
||
"[Arg list not available until function definition is loaded.]")
|
||
(t t)))
|
||
|
||
(defun help--make-usage (function arglist)
|
||
(cons (if (symbolp function) function 'anonymous)
|
||
(mapcar (lambda (arg)
|
||
(cond
|
||
;; Parameter name.
|
||
((symbolp arg)
|
||
(let ((name (symbol-name arg)))
|
||
(cond
|
||
((string-match "\\`&" name) arg)
|
||
((string-match "\\`_." name)
|
||
(intern (upcase (substring name 1))))
|
||
(t (intern (upcase name))))))
|
||
;; Parameter with a default value (from
|
||
;; cl-defgeneric etc).
|
||
((and (consp arg)
|
||
(symbolp (car arg)))
|
||
(cons (intern (upcase (symbol-name (car arg)))) (cdr arg)))
|
||
;; Something else.
|
||
(t arg)))
|
||
arglist)))
|
||
|
||
(define-obsolete-function-alias 'help-make-usage 'help--make-usage "25.1")
|
||
|
||
(defun help--make-usage-docstring (fn arglist)
|
||
(let ((print-escape-newlines t))
|
||
(help--docstring-quote (format "%S" (help--make-usage fn arglist)))))
|
||
|
||
|
||
|
||
;; Just some quote-like characters for now. TODO: generate this stuff
|
||
;; from official Unicode data.
|
||
(defconst help-uni-confusables
|
||
'((#x2018 . "'") ;; LEFT SINGLE QUOTATION MARK
|
||
(#x2019 . "'") ;; RIGHT SINGLE QUOTATION MARK
|
||
(#x201B . "'") ;; SINGLE HIGH-REVERSED-9 QUOTATION MARK
|
||
(#x201C . "\"") ;; LEFT DOUBLE QUOTATION MARK
|
||
(#x201D . "\"") ;; RIGHT DOUBLE QUOTATION MARK
|
||
(#x201F . "\"") ;; DOUBLE HIGH-REVERSED-9 QUOTATION MARK
|
||
(#x301E . "\"") ;; DOUBLE PRIME QUOTATION MARK
|
||
(#xFF02 . "'") ;; FULLWIDTH QUOTATION MARK
|
||
(#xFF07 . "'") ;; FULLWIDTH APOSTROPHE
|
||
)
|
||
"An alist of confusable characters to give hints about.
|
||
Each alist element is of the form (CHAR . REPLACEMENT), where
|
||
CHAR is the potentially confusable character, and REPLACEMENT is
|
||
the suggested string to use instead. See
|
||
`help-uni-confusable-suggestions'.")
|
||
|
||
(defconst help-uni-confusables-regexp
|
||
(concat "[" (mapcar #'car help-uni-confusables) "]")
|
||
"Regexp matching any character listed in `help-uni-confusables'.")
|
||
|
||
(defun help-uni-confusable-suggestions (string)
|
||
"Return a message describing confusables in STRING."
|
||
(let ((i 0)
|
||
(confusables nil))
|
||
(while (setq i (string-match help-uni-confusables-regexp string i))
|
||
(let ((replacement (alist-get (aref string i) help-uni-confusables)))
|
||
(push (aref string i) confusables)
|
||
(setq string (replace-match replacement t t string))
|
||
(setq i (+ i (length replacement)))))
|
||
(when confusables
|
||
(format-message
|
||
(ngettext
|
||
"Found confusable character: %s, perhaps you meant: `%s'?"
|
||
"Found confusable characters: %s; perhaps you meant: `%s'?"
|
||
(length confusables))
|
||
(mapconcat (lambda (c) (format-message "`%c'" c))
|
||
confusables ", ")
|
||
string))))
|
||
|
||
(defun help-command-error-confusable-suggestions (data _context _signal)
|
||
(pcase data
|
||
(`(void-variable ,var)
|
||
(let ((suggestions (help-uni-confusable-suggestions
|
||
(symbol-name var))))
|
||
(when suggestions
|
||
(princ (concat "\n " suggestions) t))))
|
||
(_ nil)))
|
||
|
||
(add-function :after command-error-function
|
||
#'help-command-error-confusable-suggestions)
|
||
|
||
|
||
(provide 'help)
|
||
|
||
;;; help.el ends here
|