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1484 lines
61 KiB
EmacsLisp
1484 lines
61 KiB
EmacsLisp
;;; help-fns.el --- Complex help functions -*- lexical-binding: t -*-
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;; Copyright (C) 1985-1986, 1993-1994, 1998-2019 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 file contains those help commands which are complicated, and
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;; which may not be used in every session. For example
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;; `describe-function' will probably be heavily used when doing elisp
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;; programming, but not if just editing C files. Simpler help commands
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;; are in help.el
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;;; Code:
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(require 'cl-lib)
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(require 'help-mode)
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(require 'radix-tree)
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(defvar help-fns-describe-function-functions nil
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"List of functions to run in help buffer in `describe-function'.
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Those functions will be run after the header line and argument
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list was inserted, and before the documentation will be inserted.
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The functions will receive the function name as argument.
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They can assume that a newline was output just before they were called,
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and they should terminate any of their own output with a newline.
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By convention they should indent their output by 2 spaces.")
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(defvar help-fns-describe-variable-functions nil
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"List of functions to run in help buffer in `describe-variable'.
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Those functions will be run after the header line and value was inserted,
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and before the documentation will be inserted.
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The functions will receive the variable name as argument.
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They can assume that a newline was output just before they were called,
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and they should terminate any of their own output with a newline.
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By convention they should indent their output by 2 spaces.
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Current buffer is the buffer in which we queried the variable,
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and the output should go to `standard-output'.")
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;; Functions
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(defvar help-definition-prefixes nil
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;; FIXME: We keep `definition-prefixes' as a hash-table so as to
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;; avoid pre-loading radix-tree and because it takes slightly less
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;; memory. But when we use this table it's more efficient to
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;; represent it as a radix tree, since the main operation is to do
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;; `radix-tree-prefixes'. Maybe we should just bite the bullet and
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;; use a radix tree for `definition-prefixes' (it's not *that*
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;; costly, really).
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"Radix-tree representation replacing `definition-prefixes'.")
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(defun help-definition-prefixes ()
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"Return the up-to-date radix-tree form of `definition-prefixes'."
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(when (> (hash-table-count definition-prefixes) 0)
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(maphash (lambda (prefix files)
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(let ((old (radix-tree-lookup help-definition-prefixes prefix)))
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(setq help-definition-prefixes
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(radix-tree-insert help-definition-prefixes
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prefix (append old files)))))
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definition-prefixes)
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(clrhash definition-prefixes))
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help-definition-prefixes)
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(defun help--loaded-p (file)
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"Try and figure out if FILE has already been loaded."
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;; FIXME: this regexp business is not good enough: for file
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;; `toto', it will say `toto' is loaded when in reality it was
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;; just cedet/semantic/toto that has been loaded.
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(or (let ((feature (intern-soft file)))
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(and feature (featurep feature)))
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(let* ((re (load-history-regexp file))
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(done nil))
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(dolist (x load-history)
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(and (stringp (car x)) (string-match-p re (car x)) (setq done t)))
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done)))
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(defun help--load-prefixes (prefixes)
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(pcase-dolist (`(,prefix . ,files) prefixes)
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(setq help-definition-prefixes
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(radix-tree-insert help-definition-prefixes prefix nil))
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(dolist (file files)
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;; FIXME: Should we scan help-definition-prefixes to remove
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;; other prefixes of the same file?
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(unless (help--loaded-p file)
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(with-demoted-errors "while loading: %S"
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(load file 'noerror 'nomessage))))))
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(defcustom help-enable-completion-auto-load t
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"Whether completion for Help commands can perform autoloading.
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If non-nil, whenever invoking completion for `describe-function'
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or `describe-variable' load files that might contain definitions
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with the current prefix. The files are chosen according to
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`definition-prefixes'."
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:type 'boolean
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:group 'help
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:version "26.3")
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(defun help--symbol-completion-table (string pred action)
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(when help-enable-completion-auto-load
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(let ((prefixes (radix-tree-prefixes (help-definition-prefixes) string)))
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(help--load-prefixes prefixes)))
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(let ((prefix-completions
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(and help-enable-completion-auto-load
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(mapcar #'intern (all-completions string definition-prefixes)))))
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(complete-with-action action obarray string
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(if pred (lambda (sym)
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(or (funcall pred sym)
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(memq sym prefix-completions)))))))
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(defvar describe-function-orig-buffer nil
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"Buffer that was current when `describe-function' was invoked.
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Functions on `help-fns-describe-function-functions' can use this
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to get buffer-local values.")
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;;;###autoload
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(defun describe-function (function)
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"Display the full documentation of FUNCTION (a symbol).
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When called from lisp, FUNCTION may also be a function object."
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(interactive
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(let* ((fn (function-called-at-point))
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(enable-recursive-minibuffers t)
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(val (completing-read
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(if fn
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(format "Describe function (default %s): " fn)
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"Describe function: ")
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#'help--symbol-completion-table
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(lambda (f) (or (fboundp f) (get f 'function-documentation)))
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t nil nil
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(and fn (symbol-name fn)))))
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(unless (equal val "")
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(setq fn (intern val)))
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(unless (and fn (symbolp fn))
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(user-error "You didn't specify a function symbol"))
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(unless (or (fboundp fn) (get fn 'function-documentation))
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(user-error "Symbol's function definition is void: %s" fn))
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(list fn)))
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;; We save describe-function-orig-buffer on the help xref stack, so
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;; it is restored by the back/forward buttons. 'help-buffer'
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;; expects (current-buffer) to be a help buffer when processing
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;; those buttons, so we can't change the current buffer before
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;; calling that.
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(let ((describe-function-orig-buffer
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(or describe-function-orig-buffer
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(current-buffer))))
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(help-setup-xref
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(list (lambda (function buffer)
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(let ((describe-function-orig-buffer
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(if (buffer-live-p buffer) buffer)))
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(describe-function function)))
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function describe-function-orig-buffer)
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(called-interactively-p 'interactive))
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(save-excursion
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(with-help-window (help-buffer)
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(if (get function 'reader-construct)
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(princ function)
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(prin1 function))
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;; Use " is " instead of a colon so that
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;; it is easier to get out the function name using forward-sexp.
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(princ " is ")
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(describe-function-1 function)
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(with-current-buffer standard-output
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;; Return the text we displayed.
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(buffer-string))))
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))
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;; Could be this, if we make symbol-file do the work below.
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;; (defun help-C-file-name (subr-or-var kind)
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;; "Return the name of the C file where SUBR-OR-VAR is defined.
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;; KIND should be `var' for a variable or `subr' for a subroutine."
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;; (symbol-file (if (symbolp subr-or-var) subr-or-var
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;; (subr-name subr-or-var))
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;; (if (eq kind 'var) 'defvar 'defun)))
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;;;###autoload
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(defun help-C-file-name (subr-or-var kind)
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"Return the name of the C file where SUBR-OR-VAR is defined.
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KIND should be `var' for a variable or `subr' for a subroutine."
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(let ((docbuf (get-buffer-create " *DOC*"))
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(name (if (eq 'var kind)
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(concat "V" (symbol-name subr-or-var))
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(concat "F" (subr-name (advice--cd*r subr-or-var))))))
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(with-current-buffer docbuf
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(goto-char (point-min))
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(if (eobp)
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(insert-file-contents-literally
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(expand-file-name internal-doc-file-name doc-directory)))
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(let ((file (catch 'loop
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(while t
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(let ((pnt (search-forward (concat "\^_" name "\n"))))
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(re-search-backward "\^_S\\(.*\\)")
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(let ((file (match-string 1)))
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(if (member file build-files)
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(throw 'loop file)
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(goto-char pnt))))))))
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(if (string-match "^ns.*\\(\\.o\\|obj\\)\\'" file)
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(setq file (replace-match ".m" t t file 1))
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(if (string-match "\\.\\(o\\|obj\\)\\'" file)
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(setq file (replace-match ".c" t t file))))
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(if (string-match "\\.\\(c\\|m\\)\\'" file)
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(concat "src/" file)
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file)))))
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(defcustom help-downcase-arguments nil
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"If non-nil, argument names in *Help* buffers are downcased."
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:type 'boolean
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:group 'help
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:version "23.2")
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(defun help-highlight-arg (arg)
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"Highlight ARG as an argument name for a *Help* buffer.
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Return ARG in face `help-argument-name'; ARG is also downcased
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if the variable `help-downcase-arguments' is non-nil."
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(propertize (if help-downcase-arguments (downcase arg) arg)
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'face 'help-argument-name))
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(defun help-do-arg-highlight (doc args)
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(with-syntax-table (make-syntax-table emacs-lisp-mode-syntax-table)
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(modify-syntax-entry ?\- "w")
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(dolist (arg args)
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(setq doc (replace-regexp-in-string
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;; This is heuristic, but covers all common cases
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;; except ARG1-ARG2
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(concat "\\<" ; beginning of word
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"\\(?:[a-z-]*-\\)?" ; for xxx-ARG
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"\\("
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(regexp-quote arg)
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"\\)"
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"\\(?:es\\|s\\|th\\)?" ; for ARGth, ARGs
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"\\(?:-[a-z0-9-]+\\)?" ; for ARG-xxx, ARG-n
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"\\(?:-[{([<`\"‘].*?\\)?"; for ARG-{x}, (x), <x>, [x], `x', ‘x’
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"\\>") ; end of word
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(help-highlight-arg arg)
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doc t t 1)))
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doc))
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(defun help-highlight-arguments (usage doc &rest args)
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(when (and usage (string-match "^(" usage))
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(with-temp-buffer
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(insert usage)
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(goto-char (point-min))
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(let ((case-fold-search nil)
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(next (not (or args (looking-at "\\["))))
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(opt nil))
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;; Make a list of all arguments
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(skip-chars-forward "^ ")
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(while next
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(or opt (not (looking-at " &")) (setq opt t))
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(if (not (re-search-forward " \\([\\[(]*\\)\\([^] &).]+\\)" nil t))
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(setq next nil)
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(setq args (cons (match-string 2) args))
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(when (and opt (string= (match-string 1) "("))
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;; A pesky CL-style optional argument with default value,
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;; so let's skip over it
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(search-backward "(")
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(goto-char (scan-sexps (point) 1)))))
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;; Highlight arguments in the USAGE string
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(setq usage (help-do-arg-highlight (buffer-string) args))
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;; Highlight arguments in the DOC string
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(setq doc (and doc (help-do-arg-highlight doc args))))))
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;; Return value is like the one from help-split-fundoc, but highlighted
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(cons usage doc))
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;; The following function was compiled from the former functions
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;; `describe-simplify-lib-file-name' and `find-source-lisp-file' with
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;; some excerpts from `describe-function-1' and `describe-variable'.
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;; The only additional twists provided are (1) locate the defining file
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;; for autoloaded functions, and (2) give preference to files in the
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;; "install directory" (directories found via `load-path') rather than
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;; to files in the "compile directory" (directories found by searching
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;; the loaddefs.el file). We autoload it because it's also used by
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;; `describe-face' (instead of `describe-simplify-lib-file-name').
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;;;###autoload
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(defun find-lisp-object-file-name (object type)
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"Guess the file that defined the Lisp object OBJECT, of type TYPE.
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OBJECT should be a symbol associated with a function, variable, or face;
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alternatively, it can be a function definition.
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If TYPE is `defvar', search for a variable definition.
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If TYPE is `defface', search for a face definition.
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If TYPE is not a symbol, search for a function definition.
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The return value is the absolute name of a readable file where OBJECT is
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defined. If several such files exist, preference is given to a file
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found via `load-path'. The return value can also be `C-source', which
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means that OBJECT is a function or variable defined in C. If no
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suitable file is found, return nil."
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(let* ((autoloaded (autoloadp type))
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(file-name (or (and autoloaded (nth 1 type))
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(symbol-file
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;; FIXME: Why do we have this weird "If TYPE is the
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;; value returned by `symbol-function' for a function
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;; symbol" exception?
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object (or (if (symbolp type) type) 'defun)))))
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(cond
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(autoloaded
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;; An autoloaded function: Locate the file since `symbol-function'
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;; has only returned a bare string here.
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(setq file-name
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(locate-file file-name load-path '(".el" ".elc") 'readable)))
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((and (stringp file-name)
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(string-match "[.]*loaddefs.el\\'" file-name))
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;; An autoloaded variable or face. Visit loaddefs.el in a buffer
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;; and try to extract the defining file. The following form is
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;; from `describe-function-1' and `describe-variable'.
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(let ((location
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(condition-case nil
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(find-function-search-for-symbol object nil file-name)
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(error nil))))
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(when (cdr location)
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(with-current-buffer (car location)
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(goto-char (cdr location))
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(when (re-search-backward
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"^;;; Generated autoloads from \\(.*\\)" nil t)
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(setq file-name
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(locate-file
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(file-name-sans-extension
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(match-string-no-properties 1))
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load-path '(".el" ".elc") 'readable))))))))
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(cond
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((and (not file-name) (subrp type))
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;; A built-in function. The form is from `describe-function-1'.
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(if (get-buffer " *DOC*")
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(help-C-file-name type 'subr)
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'C-source))
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((and (not file-name) (symbolp object)
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(integerp (get object 'variable-documentation)))
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;; A variable defined in C. The form is from `describe-variable'.
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(if (get-buffer " *DOC*")
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(help-C-file-name object 'var)
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'C-source))
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((not (stringp file-name))
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;; If we don't have a file-name string by now, we lost.
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nil)
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;; Now, `file-name' should have become an absolute file name.
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;; For files loaded from ~/.foo.elc, try ~/.foo.
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;; This applies to config files like ~/.emacs,
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;; which people sometimes compile.
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((let (fn)
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(and (string-match "\\`\\..*\\.elc\\'"
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(file-name-nondirectory file-name))
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(string-equal (file-name-directory file-name)
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(file-name-as-directory (expand-file-name "~")))
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(file-readable-p (setq fn (file-name-sans-extension file-name)))
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fn)))
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;; When the Elisp source file can be found in the install
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;; directory, return the name of that file.
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((let ((lib-name
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(if (string-match "[.]elc\\'" file-name)
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(substring-no-properties file-name 0 -1)
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file-name)))
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(or (and (file-readable-p lib-name) lib-name)
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;; The library might be compressed.
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(and (file-readable-p (concat lib-name ".gz")) lib-name))))
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((let* ((lib-name (file-name-nondirectory file-name))
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;; The next form is from `describe-simplify-lib-file-name'.
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(file-name
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;; Try converting the absolute file name to a library
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;; name, convert that back to a file name and see if we
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;; get the original one. If so, they are equivalent.
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(if (equal file-name (locate-file lib-name load-path '("")))
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(if (string-match "[.]elc\\'" lib-name)
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(substring-no-properties lib-name 0 -1)
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lib-name)
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file-name))
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(src-file (locate-library file-name t nil 'readable)))
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(and src-file (file-readable-p src-file) src-file))))))
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(defun help-fns--key-bindings (function)
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(when (commandp function)
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(let ((pt2 (with-current-buffer standard-output (point)))
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(remapped (command-remapping function)))
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(unless (memq remapped '(ignore undefined))
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(let ((keys (where-is-internal
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(or remapped function) overriding-local-map nil nil))
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non-modified-keys)
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(if (and (eq function 'self-insert-command)
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(vectorp (car-safe keys))
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(consp (aref (car keys) 0)))
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(princ "It is bound to many ordinary text characters.\n")
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;; Which non-control non-meta keys run this command?
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||
(dolist (key keys)
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(if (member (event-modifiers (aref key 0)) '(nil (shift)))
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(push key non-modified-keys)))
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(when remapped
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(princ "Its keys are remapped to ")
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(princ (if (symbolp remapped)
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(format-message "`%s'" remapped)
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"an anonymous command"))
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(princ ".\n"))
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(when keys
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(princ (if remapped
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"Without this remapping, it would be bound to "
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"It is bound to "))
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;; If lots of ordinary text characters run this command,
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||
;; don't mention them one by one.
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||
(if (< (length non-modified-keys) 10)
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(princ (mapconcat #'key-description keys ", "))
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(dolist (key non-modified-keys)
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(setq keys (delq key keys)))
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||
(if keys
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||
(progn
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(princ (mapconcat #'key-description keys ", "))
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(princ ", and many ordinary text characters"))
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(princ "many ordinary text characters"))))
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(when (or remapped keys non-modified-keys)
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(princ ".")
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(terpri)))))
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(with-current-buffer standard-output
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||
(fill-region-as-paragraph pt2 (point))
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||
(unless (looking-back "\n\n" (- (point) 2))
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||
(terpri))))))
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(defun help-fns--compiler-macro (function)
|
||
(let ((handler (function-get function 'compiler-macro)))
|
||
(when handler
|
||
(insert " This function has a compiler macro")
|
||
(if (symbolp handler)
|
||
(progn
|
||
(insert (format-message " `%s'" handler))
|
||
(save-excursion
|
||
(re-search-backward (substitute-command-keys "`\\([^`']+\\)'")
|
||
nil t)
|
||
(help-xref-button 1 'help-function handler)))
|
||
;; FIXME: Obsolete since 24.4.
|
||
(let ((lib (get function 'compiler-macro-file)))
|
||
(when (stringp lib)
|
||
(insert (format-message " in `%s'" lib))
|
||
(save-excursion
|
||
(re-search-backward (substitute-command-keys "`\\([^`']+\\)'")
|
||
nil t)
|
||
(help-xref-button 1 'help-function-cmacro function lib)))))
|
||
(insert ".\n"))))
|
||
|
||
(defun help-fns--signature (function doc real-def real-function buffer)
|
||
"Insert usage at point and return docstring. With highlighting."
|
||
(if (keymapp function)
|
||
doc ; If definition is a keymap, skip arglist note.
|
||
(let* ((advertised (gethash real-def advertised-signature-table t))
|
||
(arglist (if (listp advertised)
|
||
advertised (help-function-arglist real-def)))
|
||
(usage (help-split-fundoc doc function)))
|
||
(if usage (setq doc (cdr usage)))
|
||
(let* ((use (cond
|
||
((and usage (not (listp advertised))) (car usage))
|
||
((listp arglist)
|
||
(help--make-usage-docstring function arglist))
|
||
((stringp arglist) arglist)
|
||
;; Maybe the arglist is in the docstring of a symbol
|
||
;; this one is aliased to.
|
||
((let ((fun real-function))
|
||
(while (and (symbolp fun)
|
||
(setq fun (symbol-function fun))
|
||
(not (setq usage (help-split-fundoc
|
||
(documentation fun)
|
||
function)))))
|
||
usage)
|
||
(car usage))
|
||
((or (stringp real-def)
|
||
(vectorp real-def))
|
||
(format "\nMacro: %s"
|
||
(help--docstring-quote
|
||
(format-kbd-macro real-def))))
|
||
(t "[Missing arglist. Please make a bug report.]")))
|
||
;; Insert "`X", not "(\` X)", when documenting `X.
|
||
(use1 (replace-regexp-in-string
|
||
"\\`(\\\\=\\\\\\\\=` \\([^\n ]*\\))\\'"
|
||
"\\\\=`\\1" use t))
|
||
(high (if buffer
|
||
(let (subst-use1 subst-doc)
|
||
(with-current-buffer buffer
|
||
(setq subst-use1 (substitute-command-keys use1))
|
||
(setq subst-doc (substitute-command-keys doc)))
|
||
(help-highlight-arguments subst-use1 subst-doc))
|
||
(cons use1 doc))))
|
||
(let ((fill-begin (point))
|
||
(high-usage (car high))
|
||
(high-doc (cdr high)))
|
||
(unless (and (symbolp function)
|
||
(get function 'reader-construct))
|
||
(insert high-usage "\n"))
|
||
(fill-region fill-begin (point))
|
||
high-doc)))))
|
||
|
||
(defun help-fns--parent-mode (function)
|
||
;; If this is a derived mode, link to the parent.
|
||
(let ((parent-mode (and (symbolp function)
|
||
(get function
|
||
'derived-mode-parent))))
|
||
(when parent-mode
|
||
(insert (substitute-command-keys " Parent mode: `"))
|
||
(let ((beg (point)))
|
||
(insert (format "%s" parent-mode))
|
||
(make-text-button beg (point)
|
||
'type 'help-function
|
||
'help-args (list parent-mode)))
|
||
(insert (substitute-command-keys "'.\n")))))
|
||
|
||
(defun help-fns--obsolete (function)
|
||
;; Ignore lambda constructs, keyboard macros, etc.
|
||
(let* ((obsolete (and (symbolp function)
|
||
(get function 'byte-obsolete-info)))
|
||
(use (car obsolete)))
|
||
(when obsolete
|
||
(insert " This "
|
||
(if (eq (car-safe (symbol-function function)) 'macro)
|
||
"macro"
|
||
"function")
|
||
" is obsolete")
|
||
(when (nth 2 obsolete)
|
||
(insert (format " since %s" (nth 2 obsolete))))
|
||
(insert (cond ((stringp use) (concat ";\n " use))
|
||
(use (format-message ";\n use `%s' instead." use))
|
||
(t "."))
|
||
"\n"))))
|
||
|
||
;; We could use `symbol-file' but this is a wee bit more efficient.
|
||
(defun help-fns--autoloaded-p (function file)
|
||
"Return non-nil if FUNCTION has previously been autoloaded.
|
||
FILE is the file where FUNCTION was probably defined."
|
||
(let* ((file (file-name-sans-extension (file-truename file)))
|
||
(load-hist load-history)
|
||
(target (cons t function))
|
||
found)
|
||
(while (and load-hist (not found))
|
||
(and (stringp (caar load-hist))
|
||
(equal (file-name-sans-extension (caar load-hist)) file)
|
||
(setq found (member target (cdar load-hist))))
|
||
(setq load-hist (cdr load-hist)))
|
||
found))
|
||
|
||
(defun help-fns--interactive-only (function)
|
||
"Insert some help blurb if FUNCTION should only be used interactively."
|
||
;; Ignore lambda constructs, keyboard macros, etc.
|
||
(and (symbolp function)
|
||
(not (eq (car-safe (symbol-function function)) 'macro))
|
||
(let* ((interactive-only
|
||
(or (get function 'interactive-only)
|
||
(if (boundp 'byte-compile-interactive-only-functions)
|
||
(memq function
|
||
byte-compile-interactive-only-functions)))))
|
||
(when interactive-only
|
||
(insert " This function is for interactive use only"
|
||
;; Cf byte-compile-form.
|
||
(cond ((stringp interactive-only)
|
||
(format ";\n in Lisp code %s" interactive-only))
|
||
((and (symbolp 'interactive-only)
|
||
(not (eq interactive-only t)))
|
||
(format-message ";\n in Lisp code use `%s' instead."
|
||
interactive-only))
|
||
(t "."))
|
||
"\n")))))
|
||
|
||
(add-hook 'help-fns-describe-function-functions #'help-fns--side-effects)
|
||
(defun help-fns--side-effects (function)
|
||
(when (and (symbolp function)
|
||
(or (function-get function 'pure)
|
||
(function-get function 'side-effect-free)))
|
||
(insert " This function does not change global state, "
|
||
"including the match data.\n")))
|
||
|
||
(defun help-fns--first-release (symbol)
|
||
"Return the likely first release that defined SYMBOL, or nil."
|
||
;; Code below relies on the etc/NEWS* files.
|
||
;; FIXME: Maybe we should also use the */ChangeLog* files when available.
|
||
;; FIXME: Maybe we should also look for announcements of the addition
|
||
;; of the *packages* in which the function is defined.
|
||
(let* ((name (symbol-name symbol))
|
||
(re (concat "\\_<" (regexp-quote name) "\\_>"))
|
||
(news (directory-files data-directory t "\\`NEWS.[1-9]"))
|
||
(place nil)
|
||
(first nil))
|
||
(with-temp-buffer
|
||
(dolist (f news)
|
||
(erase-buffer)
|
||
(insert-file-contents f)
|
||
(goto-char (point-min))
|
||
(search-forward "\n*")
|
||
(while (re-search-forward re nil t)
|
||
(let ((pos (match-beginning 0)))
|
||
(save-excursion
|
||
;; Almost all entries are of the form "* ... in Emacs NN.MM."
|
||
;; but there are also a few in the form "* Emacs NN.MM is a bug
|
||
;; fix release ...".
|
||
(if (not (re-search-backward "^\\*.* Emacs \\([0-9.]+[0-9]\\)"
|
||
nil t))
|
||
(message "Ref found in non-versioned section in %S"
|
||
(file-name-nondirectory f))
|
||
(let ((version (match-string 1)))
|
||
(when (or (null first) (version< version first))
|
||
(setq place (list f pos))
|
||
(setq first version)))))))))
|
||
(when first
|
||
(make-text-button first nil 'type 'help-news 'help-args place))
|
||
first))
|
||
|
||
(add-hook 'help-fns-describe-function-functions
|
||
#'help-fns--mention-first-release)
|
||
(add-hook 'help-fns-describe-variable-functions
|
||
#'help-fns--mention-first-release)
|
||
(defun help-fns--mention-first-release (object)
|
||
(let ((first (if (symbolp object) (help-fns--first-release object))))
|
||
(when first
|
||
(with-current-buffer standard-output
|
||
(insert (format " Probably introduced at or before Emacs version %s.\n"
|
||
first))))))
|
||
|
||
(defun help-fns-short-filename (filename)
|
||
(let* ((abbrev (abbreviate-file-name filename))
|
||
(short abbrev))
|
||
(dolist (dir load-path)
|
||
(let ((rel (file-relative-name filename dir)))
|
||
(if (< (length rel) (length short))
|
||
(setq short rel)))
|
||
(let ((rel (file-relative-name abbrev dir)))
|
||
(if (< (length rel) (length short))
|
||
(setq short rel))))
|
||
short))
|
||
|
||
(defun help-fns--analyze-function (function)
|
||
;; FIXME: Document/explain the differences between FUNCTION,
|
||
;; REAL-FUNCTION, DEF, and REAL-DEF.
|
||
"Return information about FUNCTION.
|
||
Returns a list of the form (REAL-FUNCTION DEF ALIASED REAL-DEF)."
|
||
(let* ((advised (and (symbolp function)
|
||
(advice--p (advice--symbol-function function))))
|
||
;; If the function is advised, use the symbol that has the
|
||
;; real definition, if that symbol is already set up.
|
||
(real-function
|
||
(or (and advised
|
||
(advice--cd*r (advice--symbol-function function)))
|
||
function))
|
||
;; Get the real definition, if any.
|
||
(def (if (symbolp real-function)
|
||
(cond ((symbol-function real-function))
|
||
((get real-function 'function-documentation)
|
||
nil)
|
||
(t (signal 'void-function (list real-function))))
|
||
real-function))
|
||
(aliased (and def
|
||
(or (symbolp def)
|
||
;; Advised & aliased function.
|
||
(and advised (symbolp real-function)
|
||
(not (eq 'autoload (car-safe def))))
|
||
(and (subrp def)
|
||
(not (string= (subr-name def)
|
||
(symbol-name function)))))))
|
||
(real-def (cond
|
||
((and aliased (not (subrp def)))
|
||
(let ((f real-function))
|
||
(while (and (fboundp f)
|
||
(symbolp (symbol-function f)))
|
||
(setq f (symbol-function f)))
|
||
f))
|
||
((subrp def) (intern (subr-name def)))
|
||
(t def))))
|
||
(list real-function def aliased real-def)))
|
||
|
||
(defun help-fns-function-description-header (function)
|
||
"Print a line describing FUNCTION to `standard-output'."
|
||
(pcase-let* ((`(,_real-function ,def ,aliased ,real-def)
|
||
(help-fns--analyze-function function))
|
||
(file-name (find-lisp-object-file-name function (if aliased 'defun
|
||
def)))
|
||
(beg (if (and (or (byte-code-function-p def)
|
||
(keymapp def)
|
||
(memq (car-safe def) '(macro lambda closure)))
|
||
(stringp file-name)
|
||
(help-fns--autoloaded-p function file-name))
|
||
(concat
|
||
"an autoloaded " (if (commandp def)
|
||
"interactive "))
|
||
(if (commandp def) "an interactive " "a "))))
|
||
|
||
;; Print what kind of function-like object FUNCTION is.
|
||
(princ (cond ((or (stringp def) (vectorp def))
|
||
"a keyboard macro")
|
||
((and (symbolp function)
|
||
(get function 'reader-construct))
|
||
"a reader construct")
|
||
;; Aliases are Lisp functions, so we need to check
|
||
;; aliases before functions.
|
||
(aliased
|
||
(format-message "an alias for `%s'" real-def))
|
||
((subrp def)
|
||
(concat beg (if (eq 'unevalled (cdr (subr-arity def)))
|
||
"special form"
|
||
"built-in function")))
|
||
((autoloadp def)
|
||
(format "an autoloaded %s"
|
||
(cond
|
||
((commandp def) "interactive Lisp function")
|
||
((eq (nth 4 def) 'keymap) "keymap")
|
||
((nth 4 def) "Lisp macro")
|
||
(t "Lisp function"))))
|
||
((or (eq (car-safe def) 'macro)
|
||
;; For advised macros, def is a lambda
|
||
;; expression or a byte-code-function-p, so we
|
||
;; need to check macros before functions.
|
||
(macrop function))
|
||
(concat beg "Lisp macro"))
|
||
((byte-code-function-p def)
|
||
(concat beg "compiled Lisp function"))
|
||
((module-function-p def)
|
||
(concat beg "module function"))
|
||
((eq (car-safe def) 'lambda)
|
||
(concat beg "Lisp function"))
|
||
((eq (car-safe def) 'closure)
|
||
(concat beg "Lisp closure"))
|
||
((keymapp def)
|
||
(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)))
|
||
(concat beg (if is-full "keymap" "sparse keymap"))))
|
||
(t "")))
|
||
|
||
(if (and aliased (not (fboundp real-def)))
|
||
(princ ",\nwhich is not defined. Please make a bug report.")
|
||
(with-current-buffer standard-output
|
||
(save-excursion
|
||
(save-match-data
|
||
(when (re-search-backward (substitute-command-keys
|
||
"alias for `\\([^`']+\\)'")
|
||
nil t)
|
||
(help-xref-button 1 'help-function real-def)))))
|
||
|
||
(when file-name
|
||
;; We used to add .el to the file name,
|
||
;; but that's completely wrong when the user used load-file.
|
||
(princ (format-message " in `%s'"
|
||
(if (eq file-name 'C-source)
|
||
"C source code"
|
||
(help-fns-short-filename file-name))))
|
||
;; Make a hyperlink to the library.
|
||
(with-current-buffer standard-output
|
||
(save-excursion
|
||
(re-search-backward (substitute-command-keys "`\\([^`']+\\)'")
|
||
nil t)
|
||
(help-xref-button 1 'help-function-def function file-name))))
|
||
(princ "."))))
|
||
|
||
(defun help-fns--ensure-empty-line ()
|
||
(unless (eolp) (insert "\n"))
|
||
(unless (eq ?\n (char-before (1- (point)))) (insert "\n")))
|
||
|
||
;;;###autoload
|
||
(defun describe-function-1 (function)
|
||
(let ((pt1 (with-current-buffer (help-buffer) (point))))
|
||
(help-fns-function-description-header function)
|
||
(with-current-buffer (help-buffer)
|
||
(fill-region-as-paragraph (save-excursion (goto-char pt1) (forward-line 0) (point))
|
||
(point))))
|
||
(terpri)(terpri)
|
||
|
||
(pcase-let* ((`(,real-function ,def ,_aliased ,real-def)
|
||
(help-fns--analyze-function function))
|
||
(doc-raw (condition-case nil
|
||
;; FIXME: Maybe `documentation' should return nil
|
||
;; for invalid functions i.s.o. signaling an error.
|
||
(documentation function t)
|
||
;; E.g. an alias for a not yet defined function.
|
||
((invalid-function void-function) nil)))
|
||
(key-bindings-buffer (current-buffer)))
|
||
|
||
;; If the function is autoloaded, and its docstring has
|
||
;; key substitution constructs, load the library.
|
||
(and (autoloadp real-def) doc-raw
|
||
help-enable-auto-load
|
||
(string-match "\\([^\\]=\\|[^=]\\|\\`\\)\\\\[[{<]" doc-raw)
|
||
(autoload-do-load real-def))
|
||
|
||
(help-fns--key-bindings function)
|
||
(with-current-buffer standard-output
|
||
(let ((doc (condition-case nil
|
||
;; FIXME: Maybe `help-fns--signature' should return `doc'
|
||
;; for invalid functions i.s.o. signaling an error.
|
||
(help-fns--signature
|
||
function doc-raw
|
||
(if (subrp def) (indirect-function real-def) real-def)
|
||
real-function key-bindings-buffer)
|
||
;; E.g. an alias for a not yet defined function.
|
||
((invalid-function void-function) doc-raw))))
|
||
(help-fns--ensure-empty-line)
|
||
(run-hook-with-args 'help-fns-describe-function-functions function)
|
||
(help-fns--ensure-empty-line)
|
||
(insert (or doc "Not documented.")))
|
||
;; Avoid asking the user annoying questions if she decides
|
||
;; to save the help buffer, when her locale's codeset
|
||
;; isn't UTF-8.
|
||
(unless (memq text-quoting-style '(straight grave))
|
||
(set-buffer-file-coding-system 'utf-8)))))
|
||
|
||
;; Add defaults to `help-fns-describe-function-functions'.
|
||
(add-hook 'help-fns-describe-function-functions #'help-fns--obsolete)
|
||
(add-hook 'help-fns-describe-function-functions #'help-fns--interactive-only)
|
||
(add-hook 'help-fns-describe-function-functions #'help-fns--parent-mode)
|
||
(add-hook 'help-fns-describe-function-functions #'help-fns--compiler-macro)
|
||
|
||
|
||
;; Variables
|
||
|
||
;;;###autoload
|
||
(defun variable-at-point (&optional any-symbol)
|
||
"Return the bound variable symbol found at or before point.
|
||
Return 0 if there is no such symbol.
|
||
If ANY-SYMBOL is non-nil, don't insist the symbol be bound."
|
||
(with-syntax-table emacs-lisp-mode-syntax-table
|
||
(or (condition-case ()
|
||
(save-excursion
|
||
(skip-chars-forward "'")
|
||
(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) (boundp obj) obj)))
|
||
(error nil))
|
||
(let* ((str (find-tag-default))
|
||
(sym (if str (intern-soft str))))
|
||
(if (and sym (or any-symbol (boundp sym)))
|
||
sym
|
||
(save-match-data
|
||
(when (and str (string-match "\\`\\W*\\(.*?\\)\\W*\\'" str))
|
||
(setq sym (intern-soft (match-string 1 str)))
|
||
(and (or any-symbol (boundp sym)) sym)))))
|
||
0)))
|
||
|
||
(defun describe-variable-custom-version-info (variable)
|
||
(let ((custom-version (get variable 'custom-version))
|
||
(cpv (get variable 'custom-package-version))
|
||
(output nil))
|
||
(if custom-version
|
||
(setq output
|
||
(format "This variable was introduced, or its default value was changed, in\nversion %s of Emacs.\n"
|
||
custom-version))
|
||
(when cpv
|
||
(let* ((package (car-safe cpv))
|
||
(version (if (listp (cdr-safe cpv))
|
||
(car (cdr-safe cpv))
|
||
(cdr-safe cpv)))
|
||
(pkg-versions (assq package customize-package-emacs-version-alist))
|
||
(emacsv (cdr (assoc version pkg-versions))))
|
||
(if (and package version)
|
||
(setq output
|
||
(format (concat "This variable was introduced, or its default value was changed, in\nversion %s of the %s package"
|
||
(if emacsv
|
||
(format " that is part of Emacs %s" emacsv))
|
||
".\n")
|
||
version package))))))
|
||
output))
|
||
|
||
;;;###autoload
|
||
(defun describe-variable (variable &optional buffer frame)
|
||
"Display the full documentation of VARIABLE (a symbol).
|
||
Returns the documentation as a string, also.
|
||
If VARIABLE has a buffer-local value in BUFFER or FRAME
|
||
\(default to the current buffer and current frame),
|
||
it is displayed along with the global value."
|
||
(interactive
|
||
(let ((v (variable-at-point))
|
||
(enable-recursive-minibuffers t)
|
||
(orig-buffer (current-buffer))
|
||
val)
|
||
(setq val (completing-read
|
||
(if (symbolp v)
|
||
(format
|
||
"Describe variable (default %s): " v)
|
||
"Describe variable: ")
|
||
#'help--symbol-completion-table
|
||
(lambda (vv)
|
||
;; In case the variable only exists in the buffer
|
||
;; the command we switch back to that buffer before
|
||
;; we examine the variable.
|
||
(with-current-buffer orig-buffer
|
||
(or (get vv 'variable-documentation)
|
||
(and (boundp vv) (not (keywordp vv))))))
|
||
t nil nil
|
||
(if (symbolp v) (symbol-name v))))
|
||
(list (if (equal val "")
|
||
v (intern val)))))
|
||
(let (file-name)
|
||
(unless (buffer-live-p buffer) (setq buffer (current-buffer)))
|
||
(unless (frame-live-p frame) (setq frame (selected-frame)))
|
||
(if (not (symbolp variable))
|
||
(message "You did not specify a variable")
|
||
(save-excursion
|
||
(let ((valvoid (not (with-current-buffer buffer (boundp variable))))
|
||
val val-start-pos locus)
|
||
;; Extract the value before setting up the output buffer,
|
||
;; in case `buffer' *is* the output buffer.
|
||
(unless valvoid
|
||
(with-selected-frame frame
|
||
(with-current-buffer buffer
|
||
(setq val (symbol-value variable)
|
||
locus (variable-binding-locus variable)))))
|
||
(help-setup-xref (list #'describe-variable variable buffer)
|
||
(called-interactively-p 'interactive))
|
||
(with-help-window (help-buffer)
|
||
(with-current-buffer buffer
|
||
(prin1 variable)
|
||
(setq file-name (find-lisp-object-file-name variable 'defvar))
|
||
|
||
(princ (if file-name
|
||
(progn
|
||
(princ (format-message
|
||
" is a variable defined in `%s'.\n"
|
||
(if (eq file-name 'C-source)
|
||
"C source code"
|
||
(file-name-nondirectory file-name))))
|
||
(with-current-buffer standard-output
|
||
(save-excursion
|
||
(re-search-backward (substitute-command-keys
|
||
"`\\([^`']+\\)'")
|
||
nil t)
|
||
(help-xref-button 1 'help-variable-def
|
||
variable file-name)))
|
||
(if valvoid
|
||
"It is void as a variable."
|
||
"Its "))
|
||
(if valvoid
|
||
" is void as a variable."
|
||
(substitute-command-keys "'s ")))))
|
||
(unless valvoid
|
||
(with-current-buffer standard-output
|
||
(setq val-start-pos (point))
|
||
(princ "value is")
|
||
(let ((line-beg (line-beginning-position))
|
||
(print-rep
|
||
(let ((rep
|
||
(let ((print-quoted t)
|
||
(print-circle t))
|
||
(cl-prin1-to-string val))))
|
||
(if (and (symbolp val) (not (booleanp val)))
|
||
(format-message "`%s'" rep)
|
||
rep))))
|
||
(if (< (+ (length print-rep) (point) (- line-beg)) 68)
|
||
(insert " " print-rep)
|
||
(terpri)
|
||
(let ((buf (current-buffer)))
|
||
(with-temp-buffer
|
||
(insert print-rep)
|
||
(pp-buffer)
|
||
(let ((pp-buffer (current-buffer)))
|
||
(with-current-buffer buf
|
||
(insert-buffer-substring pp-buffer)))))
|
||
;; Remove trailing newline.
|
||
(and (= (char-before) ?\n) (delete-char -1)))
|
||
(let* ((sv (get variable 'standard-value))
|
||
(origval (and (consp sv)
|
||
(condition-case nil
|
||
(eval (car sv) t)
|
||
(error :help-eval-error))))
|
||
from)
|
||
(when (and (consp sv)
|
||
(not (equal origval val))
|
||
(not (equal origval :help-eval-error)))
|
||
(princ "\nOriginal value was \n")
|
||
(setq from (point))
|
||
(cl-prin1 origval)
|
||
(save-restriction
|
||
(narrow-to-region from (point))
|
||
(save-excursion (pp-buffer)))
|
||
(if (< (point) (+ from 20))
|
||
(delete-region (1- from) from)))))))
|
||
(terpri)
|
||
(when locus
|
||
(cond
|
||
((bufferp locus)
|
||
(princ (format "Local in buffer %s; "
|
||
(buffer-name buffer))))
|
||
((terminal-live-p locus)
|
||
(princ (format "It is a terminal-local variable; ")))
|
||
(t
|
||
(princ (format "It is local to %S" locus))))
|
||
(if (not (default-boundp variable))
|
||
(princ "globally void")
|
||
(let ((global-val (default-value variable)))
|
||
(with-current-buffer standard-output
|
||
(princ "global value is ")
|
||
(if (eq val global-val)
|
||
(princ "the same.")
|
||
(terpri)
|
||
;; Fixme: pp can take an age if you happen to
|
||
;; ask for a very large expression. We should
|
||
;; probably print it raw once and check it's a
|
||
;; sensible size before prettyprinting. -- fx
|
||
(let ((from (point)))
|
||
(cl-prin1 global-val)
|
||
(save-restriction
|
||
(narrow-to-region from (point))
|
||
(save-excursion (pp-buffer)))
|
||
;; See previous comment for this function.
|
||
;; (help-xref-on-pp from (point))
|
||
(if (< (point) (+ from 20))
|
||
(delete-region (1- from) from)))))))
|
||
(terpri))
|
||
|
||
;; If the value is large, move it to the end.
|
||
(with-current-buffer standard-output
|
||
(when (> (count-lines (point-min) (point-max)) 10)
|
||
;; Note that setting the syntax table like below
|
||
;; makes forward-sexp move over a `'s' at the end
|
||
;; of a symbol.
|
||
(set-syntax-table emacs-lisp-mode-syntax-table)
|
||
(goto-char val-start-pos)
|
||
;; The line below previously read as
|
||
;; (delete-region (point) (progn (end-of-line) (point)))
|
||
;; which suppressed display of the buffer local value for
|
||
;; large values.
|
||
(when (looking-at "value is") (replace-match ""))
|
||
(save-excursion
|
||
(insert "\n\nValue:")
|
||
(set (make-local-variable 'help-button-cache)
|
||
(point-marker)))
|
||
(insert "value is shown ")
|
||
(insert-button "below"
|
||
'action help-button-cache
|
||
'follow-link t
|
||
'help-echo "mouse-2, RET: show value")
|
||
(insert ".\n")))
|
||
(terpri)
|
||
|
||
(let* ((alias (condition-case nil
|
||
(indirect-variable variable)
|
||
(error variable)))
|
||
(doc (or (documentation-property
|
||
variable 'variable-documentation)
|
||
(documentation-property
|
||
alias 'variable-documentation))))
|
||
|
||
(with-current-buffer buffer
|
||
(run-hook-with-args 'help-fns-describe-variable-functions
|
||
variable))
|
||
|
||
(with-current-buffer standard-output
|
||
(help-fns--ensure-empty-line))
|
||
(princ "Documentation:\n")
|
||
(with-current-buffer standard-output
|
||
(insert (or doc "Not documented as a variable."))))
|
||
|
||
;; Make a link to customize if this variable can be customized.
|
||
(when (custom-variable-p variable)
|
||
(let ((customize-label "customize"))
|
||
(terpri)
|
||
(terpri)
|
||
(princ (concat "You can " customize-label " this variable."))
|
||
(with-current-buffer standard-output
|
||
(save-excursion
|
||
(re-search-backward
|
||
(concat "\\(" customize-label "\\)") nil t)
|
||
(help-xref-button 1 'help-customize-variable variable))))
|
||
;; Note variable's version or package version.
|
||
(let ((output (describe-variable-custom-version-info variable)))
|
||
(when output
|
||
(terpri)
|
||
(terpri)
|
||
(princ output))))
|
||
|
||
(with-current-buffer standard-output
|
||
;; Return the text we displayed.
|
||
(buffer-string))))))))
|
||
|
||
(add-hook 'help-fns-describe-variable-functions #'help-fns--var-safe-local)
|
||
(defun help-fns--var-safe-local (variable)
|
||
(let ((safe-var (get variable 'safe-local-variable)))
|
||
(when safe-var
|
||
(princ " This variable is safe as a file local variable ")
|
||
(princ "if its value\n satisfies the predicate ")
|
||
(princ (if (byte-code-function-p safe-var)
|
||
"which is a byte-compiled expression.\n"
|
||
(format-message "`%s'.\n" safe-var))))))
|
||
|
||
(add-hook 'help-fns-describe-variable-functions #'help-fns--var-risky)
|
||
(defun help-fns--var-risky (variable)
|
||
;; Can be both risky and safe, eg auto-fill-function.
|
||
(when (risky-local-variable-p variable)
|
||
(princ " This variable may be risky if used as a \
|
||
file-local variable.\n")
|
||
(when (assq variable safe-local-variable-values)
|
||
(princ (substitute-command-keys
|
||
" However, you have added it to \
|
||
`safe-local-variable-values'.\n")))))
|
||
|
||
(add-hook 'help-fns-describe-variable-functions #'help-fns--var-ignored-local)
|
||
(defun help-fns--var-ignored-local (variable)
|
||
(when (memq variable ignored-local-variables)
|
||
(princ " This variable is ignored as a file-local \
|
||
variable.\n")))
|
||
|
||
(add-hook 'help-fns-describe-variable-functions #'help-fns--var-file-local)
|
||
(defun help-fns--var-file-local (variable)
|
||
(when (boundp variable)
|
||
(let ((val (symbol-value variable)))
|
||
(when (member (cons variable val)
|
||
file-local-variables-alist)
|
||
(if (member (cons variable val)
|
||
dir-local-variables-alist)
|
||
(let ((file (and buffer-file-name
|
||
(not (file-remote-p buffer-file-name))
|
||
(dir-locals-find-file buffer-file-name)))
|
||
(is-directory nil))
|
||
(princ (substitute-command-keys
|
||
" This variable's value is directory-local"))
|
||
(when (consp file) ; result from cache
|
||
;; If the cache element has an mtime, we
|
||
;; assume it came from a file.
|
||
(if (nth 2 file)
|
||
;; (car file) is a directory.
|
||
(setq file (dir-locals--all-files (car file)))
|
||
;; Otherwise, assume it was set directly.
|
||
(setq file (car file)
|
||
is-directory t)))
|
||
(if (null file)
|
||
(princ ".\n")
|
||
(princ ", set ")
|
||
(princ (substitute-command-keys
|
||
(cond
|
||
(is-directory "for the directory\n `")
|
||
;; Many files matched.
|
||
((and (consp file) (cdr file))
|
||
(setq file (file-name-directory (car file)))
|
||
(format "by one of the\n %s files in the directory\n `"
|
||
dir-locals-file))
|
||
(t (setq file (car file))
|
||
"by the file\n `"))))
|
||
(with-current-buffer standard-output
|
||
(insert-text-button
|
||
file 'type 'help-dir-local-var-def
|
||
'help-args (list variable file)))
|
||
(princ (substitute-command-keys "'.\n"))))
|
||
(princ (substitute-command-keys
|
||
" This variable's value is file-local.\n")))))))
|
||
|
||
(add-hook 'help-fns-describe-variable-functions #'help-fns--var-watchpoints)
|
||
(defun help-fns--var-watchpoints (variable)
|
||
(let ((watchpoints (get-variable-watchers variable)))
|
||
(when watchpoints
|
||
(princ " Calls these functions when changed: ")
|
||
;; FIXME: Turn function names into hyperlinks.
|
||
(princ watchpoints)
|
||
(terpri))))
|
||
|
||
(add-hook 'help-fns-describe-variable-functions #'help-fns--var-obsolete)
|
||
(defun help-fns--var-obsolete (variable)
|
||
(let* ((obsolete (get variable 'byte-obsolete-variable))
|
||
(use (car obsolete)))
|
||
(when obsolete
|
||
(princ " This variable is obsolete")
|
||
(if (nth 2 obsolete)
|
||
(princ (format " since %s" (nth 2 obsolete))))
|
||
(princ (cond ((stringp use) (concat ";\n " use))
|
||
(use (format-message ";\n use `%s' instead."
|
||
(car obsolete)))
|
||
(t ".")))
|
||
(terpri))))
|
||
|
||
(add-hook 'help-fns-describe-variable-functions #'help-fns--var-alias)
|
||
(defun help-fns--var-alias (variable)
|
||
;; Mention if it's an alias.
|
||
(let ((alias (condition-case nil
|
||
(indirect-variable variable)
|
||
(error variable))))
|
||
(unless (eq alias variable)
|
||
(princ (format-message
|
||
" This variable is an alias for `%s'.\n"
|
||
alias)))))
|
||
|
||
(add-hook 'help-fns-describe-variable-functions #'help-fns--var-bufferlocal)
|
||
(defun help-fns--var-bufferlocal (variable)
|
||
(let ((permanent-local (get variable 'permanent-local))
|
||
(locus (variable-binding-locus variable)))
|
||
;; Mention if it's a local variable.
|
||
(cond
|
||
((and (local-variable-if-set-p variable)
|
||
(or (not (local-variable-p variable))
|
||
(with-temp-buffer
|
||
(local-variable-if-set-p variable))))
|
||
(princ " Automatically becomes ")
|
||
(if permanent-local
|
||
(princ "permanently "))
|
||
(princ "buffer-local when set.\n"))
|
||
((not permanent-local))
|
||
((bufferp locus)
|
||
(princ
|
||
(substitute-command-keys
|
||
" This variable's buffer-local value is permanent.\n")))
|
||
(t
|
||
(princ (substitute-command-keys
|
||
" This variable's value is permanent \
|
||
if it is given a local binding.\n"))))))
|
||
|
||
(defvar help-xref-stack-item)
|
||
|
||
;;;###autoload
|
||
(defun describe-symbol (symbol &optional buffer frame)
|
||
"Display the full documentation of SYMBOL.
|
||
Will show the info of SYMBOL as a function, variable, and/or face.
|
||
Optional arguments BUFFER and FRAME specify for which buffer and
|
||
frame to show the information about SYMBOL; they default to the
|
||
current buffer and the selected frame, respectively."
|
||
(interactive
|
||
(let* ((v-or-f (symbol-at-point))
|
||
(found (if v-or-f (cl-some (lambda (x) (funcall (nth 1 x) v-or-f))
|
||
describe-symbol-backends)))
|
||
(v-or-f (if found v-or-f (function-called-at-point)))
|
||
(found (or found v-or-f))
|
||
(enable-recursive-minibuffers t)
|
||
(val (completing-read (if found
|
||
(format
|
||
"Describe symbol (default %s): " v-or-f)
|
||
"Describe symbol: ")
|
||
#'help--symbol-completion-table
|
||
(lambda (vv)
|
||
(cl-some (lambda (x) (funcall (nth 1 x) vv))
|
||
describe-symbol-backends))
|
||
t nil nil
|
||
(if found (symbol-name v-or-f)))))
|
||
(list (if (equal val "")
|
||
v-or-f (intern val)))))
|
||
(if (not (symbolp symbol))
|
||
(user-error "You didn't specify a function or variable"))
|
||
(unless (buffer-live-p buffer) (setq buffer (current-buffer)))
|
||
(unless (frame-live-p frame) (setq frame (selected-frame)))
|
||
(with-current-buffer (help-buffer)
|
||
;; Push the previous item on the stack before clobbering the output buffer.
|
||
(help-setup-xref nil nil)
|
||
(let* ((docs
|
||
(nreverse
|
||
(delq nil
|
||
(mapcar (pcase-lambda (`(,name ,testfn ,descfn))
|
||
(when (funcall testfn symbol)
|
||
;; Don't record the current entry in the stack.
|
||
(setq help-xref-stack-item nil)
|
||
(cons name
|
||
(funcall descfn symbol buffer frame))))
|
||
describe-symbol-backends))))
|
||
(single (null (cdr docs))))
|
||
(while (cdr docs)
|
||
(goto-char (point-min))
|
||
(let ((inhibit-read-only t)
|
||
(name (caar docs)) ;Name of doc currently at BOB.
|
||
(doc (cdr (cadr docs)))) ;Doc to add at BOB.
|
||
(when doc
|
||
(insert doc)
|
||
(delete-region (point)
|
||
(progn (skip-chars-backward " \t\n") (point)))
|
||
(insert "\n\n"
|
||
(eval-when-compile
|
||
(propertize "\n" 'face '(:height 0.1 :inverse-video t)))
|
||
"\n")
|
||
(when name
|
||
(insert (symbol-name symbol)
|
||
" is also a " name "." "\n\n"))))
|
||
(setq docs (cdr docs)))
|
||
(unless single
|
||
;; Don't record the `describe-variable' item in the stack.
|
||
(setq help-xref-stack-item nil)
|
||
(help-setup-xref (list #'describe-symbol symbol) nil))
|
||
(goto-char (point-min)))))
|
||
|
||
;;;###autoload
|
||
(defun describe-syntax (&optional buffer)
|
||
"Describe the syntax specifications in the syntax table of BUFFER.
|
||
The descriptions are inserted in a help buffer, which is then displayed.
|
||
BUFFER defaults to the current buffer."
|
||
(interactive)
|
||
(setq buffer (or buffer (current-buffer)))
|
||
(help-setup-xref (list #'describe-syntax buffer)
|
||
(called-interactively-p 'interactive))
|
||
(with-help-window (help-buffer)
|
||
(let ((table (with-current-buffer buffer (syntax-table))))
|
||
(with-current-buffer standard-output
|
||
(describe-vector table 'internal-describe-syntax-value)
|
||
(while (setq table (char-table-parent table))
|
||
(insert "\nThe parent syntax table is:")
|
||
(describe-vector table 'internal-describe-syntax-value))))))
|
||
|
||
(defun help-describe-category-set (value)
|
||
(insert (cond
|
||
((null value) "default")
|
||
((char-table-p value) "deeper char-table ...")
|
||
(t (condition-case nil
|
||
(category-set-mnemonics value)
|
||
(error "invalid"))))))
|
||
|
||
;;;###autoload
|
||
(defun describe-categories (&optional buffer)
|
||
"Describe the category specifications in the current category table.
|
||
The descriptions are inserted in a buffer, which is then displayed.
|
||
If BUFFER is non-nil, then describe BUFFER's category table instead.
|
||
BUFFER should be a buffer or a buffer name."
|
||
(interactive)
|
||
(setq buffer (or buffer (current-buffer)))
|
||
(help-setup-xref (list #'describe-categories buffer)
|
||
(called-interactively-p 'interactive))
|
||
(with-help-window (help-buffer)
|
||
(let* ((table (with-current-buffer buffer (category-table)))
|
||
(docs (char-table-extra-slot table 0)))
|
||
(if (or (not (vectorp docs)) (/= (length docs) 95))
|
||
(error "Invalid first extra slot in this category table\n"))
|
||
(with-current-buffer standard-output
|
||
(setq-default help-button-cache (make-marker))
|
||
(insert "Legend of category mnemonics ")
|
||
(insert-button "(longer descriptions at the bottom)"
|
||
'action help-button-cache
|
||
'follow-link t
|
||
'help-echo "mouse-2, RET: show full legend")
|
||
(insert "\n")
|
||
(let ((pos (point)) (items 0) lines n)
|
||
(dotimes (i 95)
|
||
(if (aref docs i) (setq items (1+ items))))
|
||
(setq lines (1+ (/ (1- items) 4)))
|
||
(setq n 0)
|
||
(dotimes (i 95)
|
||
(let ((elt (aref docs i)))
|
||
(when elt
|
||
(string-match ".*" elt)
|
||
(setq elt (match-string 0 elt))
|
||
(if (>= (length elt) 17)
|
||
(setq elt (concat (substring elt 0 14) "...")))
|
||
(if (< (point) (point-max))
|
||
(move-to-column (* 20 (/ n lines)) t))
|
||
(insert (+ i ?\s) ?: elt)
|
||
(if (< (point) (point-max))
|
||
(forward-line 1)
|
||
(insert "\n"))
|
||
(setq n (1+ n))
|
||
(if (= (% n lines) 0)
|
||
(goto-char pos))))))
|
||
(goto-char (point-max))
|
||
(insert "\n"
|
||
"character(s)\tcategory mnemonics\n"
|
||
"------------\t------------------")
|
||
(describe-vector table 'help-describe-category-set)
|
||
(set-marker help-button-cache (point))
|
||
(insert "Legend of category mnemonics:\n")
|
||
(dotimes (i 95)
|
||
(let ((elt (aref docs i)))
|
||
(when elt
|
||
(if (string-match "\n" elt)
|
||
(setq elt (substring elt (match-end 0))))
|
||
(insert (+ i ?\s) ": " elt "\n"))))
|
||
(while (setq table (char-table-parent table))
|
||
(insert "\nThe parent category table is:")
|
||
(describe-vector table 'help-describe-category-set))))))
|
||
|
||
|
||
;;; Replacements for old lib-src/ programs. Don't seem especially useful.
|
||
|
||
;; Replaces lib-src/digest-doc.c.
|
||
;;;###autoload
|
||
(defun doc-file-to-man (file)
|
||
"Produce an nroff buffer containing the doc-strings from the DOC file."
|
||
(interactive (list (read-file-name "Name of DOC file: " doc-directory
|
||
internal-doc-file-name t)))
|
||
(or (file-readable-p file)
|
||
(error "Cannot read file `%s'" file))
|
||
(pop-to-buffer (generate-new-buffer "*man-doc*"))
|
||
(setq buffer-undo-list t)
|
||
(insert ".TH \"Command Summary for GNU Emacs\"\n"
|
||
".AU Richard M. Stallman\n")
|
||
(insert-file-contents file)
|
||
(let (notfirst)
|
||
(while (search-forward "\^_" nil 'move)
|
||
(if (= (following-char) ?S)
|
||
(delete-region (1- (point)) (line-end-position))
|
||
(delete-char -1)
|
||
(if notfirst
|
||
(insert "\n.DE\n")
|
||
(setq notfirst t))
|
||
(insert "\n.SH ")
|
||
(insert (if (= (following-char) ?F) "Function " "Variable "))
|
||
(delete-char 1)
|
||
(forward-line 1)
|
||
(insert ".DS L\n"))))
|
||
(insert "\n.DE\n")
|
||
(setq buffer-undo-list nil)
|
||
(nroff-mode))
|
||
|
||
;; Replaces lib-src/sorted-doc.c.
|
||
;;;###autoload
|
||
(defun doc-file-to-info (file)
|
||
"Produce a texinfo buffer with sorted doc-strings from the DOC file."
|
||
(interactive (list (read-file-name "Name of DOC file: " doc-directory
|
||
internal-doc-file-name t)))
|
||
(or (file-readable-p file)
|
||
(error "Cannot read file `%s'" file))
|
||
(let ((i 0) type name doc alist)
|
||
(with-temp-buffer
|
||
(insert-file-contents file)
|
||
;; The characters "@{}" need special treatment.
|
||
(while (re-search-forward "[@{}]" nil t)
|
||
(backward-char)
|
||
(insert "@")
|
||
(forward-char 1))
|
||
(goto-char (point-min))
|
||
(while (search-forward "\^_" nil t)
|
||
(when (/= (following-char) ?S)
|
||
(setq type (char-after)
|
||
name (buffer-substring (1+ (point)) (line-end-position))
|
||
doc (buffer-substring (line-beginning-position 2)
|
||
(if (search-forward "\^_" nil 'move)
|
||
(1- (point))
|
||
(point)))
|
||
alist (cons (list name type doc) alist))
|
||
(backward-char 1))))
|
||
(pop-to-buffer (generate-new-buffer "*info-doc*"))
|
||
(setq buffer-undo-list t)
|
||
;; Write the output header.
|
||
(insert "\\input texinfo @c -*-texinfo-*-\n"
|
||
"@setfilename emacsdoc.info\n"
|
||
"@settitle Command Summary for GNU Emacs\n"
|
||
"@finalout\n"
|
||
"\n@node Top\n"
|
||
"@unnumbered Command Summary for GNU Emacs\n\n"
|
||
"@table @asis\n\n"
|
||
"@iftex\n"
|
||
"@global@let@ITEM@item\n"
|
||
"@def@item{@filbreak@vskip5pt@ITEM}\n"
|
||
"@font@tensy cmsy10 scaled @magstephalf\n"
|
||
"@font@teni cmmi10 scaled @magstephalf\n"
|
||
"@def\\{{@tensy@char110}}\n" ; this backslash goes with cmr10
|
||
"@def|{{@tensy@char106}}\n"
|
||
"@def@{{{@tensy@char102}}\n"
|
||
"@def@}{{@tensy@char103}}\n"
|
||
"@def<{{@teni@char62}}\n"
|
||
"@def>{{@teni@char60}}\n"
|
||
"@chardef@@64\n"
|
||
"@catcode43=12\n"
|
||
"@tableindent-0.2in\n"
|
||
"@end iftex\n")
|
||
;; Sort the array by name; within each name, by type (functions first).
|
||
(setq alist (sort alist (lambda (e1 e2)
|
||
(if (string-equal (car e1) (car e2))
|
||
(<= (cadr e1) (cadr e2))
|
||
(string-lessp (car e1) (car e2))))))
|
||
;; Print each function.
|
||
(dolist (e alist)
|
||
(insert "\n@item "
|
||
(if (char-equal (cadr e) ?\F) "Function" "Variable")
|
||
" @code{" (car e) "}\n@display\n"
|
||
(nth 2 e)
|
||
"\n@end display\n")
|
||
;; Try to avoid a save size overflow in the TeX output routine.
|
||
(if (zerop (setq i (% (1+ i) 100)))
|
||
(insert "\n@end table\n@table @asis\n")))
|
||
(insert "@end table\n"
|
||
"@bye\n")
|
||
(setq buffer-undo-list nil)
|
||
(texinfo-mode)))
|
||
|
||
(provide 'help-fns)
|
||
|
||
;;; help-fns.el ends here
|