-;;; help-fns.el --- Complex help functions\r
-\r
-;; Copyright (C) 1985, 1986, 1993, 1994, 1998, 1999, 2000, 2001,\r
-;; 2002, 2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.\r
-\r
-;; Maintainer: FSF\r
-;; Keywords: help, internal\r
-\r
-;; This file is part of GNU Emacs.\r
-\r
-;; GNU Emacs is free software: you can redistribute it and/or modify\r
-;; it under the terms of the GNU General Public License as published by\r
-;; the Free Software Foundation, either version 3 of the License, or\r
-;; (at your option) any later version.\r
-\r
-;; GNU Emacs is distributed in the hope that it will be useful,\r
-;; but WITHOUT ANY WARRANTY; without even the implied warranty of\r
-;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the\r
-;; GNU General Public License for more details.\r
-\r
-;; You should have received a copy of the GNU General Public License\r
-;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.\r
-\r
-;;; Commentary:\r
-\r
-;; This file contains those help commands which are complicated, and\r
-;; which may not be used in every session. For example\r
-;; `describe-function' will probably be heavily used when doing elisp\r
-;; programming, but not if just editing C files. Simpler help commands\r
-;; are in help.el\r
-\r
-;;; Code:\r
-\r
-(require 'help-mode)\r
-\r
-;; Functions\r
-\r
-;;;###autoload\r
-(defun describe-function (function)\r
- "Display the full documentation of FUNCTION (a symbol)."\r
- (interactive\r
- (let ((fn (function-called-at-point))\r
- (enable-recursive-minibuffers t)\r
- val)\r
- (setq val (completing-read (if fn\r
- (format "Describe function (default %s): " fn)\r
- "Describe function: ")\r
- obarray 'fboundp t nil nil\r
- (and fn (symbol-name fn))))\r
- (list (if (equal val "")\r
- fn (intern val)))))\r
- (if (null function)\r
- (message "You didn't specify a function")\r
- (help-setup-xref (list #'describe-function function) (interactive-p))\r
- (save-excursion\r
- (with-help-window (help-buffer)\r
- (prin1 function)\r
- ;; Use " is " instead of a colon so that\r
- ;; it is easier to get out the function name using forward-sexp.\r
- (princ " is ")\r
- (describe-function-1 function)\r
- (with-current-buffer standard-output\r
- ;; Return the text we displayed.\r
- (buffer-string))))))\r
-\r
-(defun help-split-fundoc (docstring def)\r
- "Split a function DOCSTRING into the actual doc and the usage info.\r
-Return (USAGE . DOC) or nil if there's no usage info.\r
-DEF is the function whose usage we're looking for in DOCSTRING."\r
- ;; Functions can get the calling sequence at the end of the doc string.\r
- ;; In cases where `function' has been fset to a subr we can't search for\r
- ;; function's name in the doc string so we use `fn' as the anonymous\r
- ;; function name instead.\r
- (when (and docstring (string-match "\n\n(fn\\(\\( .*\\)?)\\)\\'" docstring))\r
- (cons (format "(%s%s"\r
- ;; Replace `fn' with the actual function name.\r
- (if (consp def) "anonymous" def)\r
- (match-string 1 docstring))\r
- (substring docstring 0 (match-beginning 0)))))\r
-\r
-(defun help-add-fundoc-usage (docstring arglist)\r
- "Add the usage info to DOCSTRING.\r
-If DOCSTRING already has a usage info, then just return it unchanged.\r
-The usage info is built from ARGLIST. DOCSTRING can be nil.\r
-ARGLIST can also be t or a string of the form \"(FUN ARG1 ARG2 ...)\"."\r
- (unless (stringp docstring) (setq docstring "Not documented"))\r
- (if (or (string-match "\n\n(fn\\(\\( .*\\)?)\\)\\'" docstring) (eq arglist t))\r
- docstring\r
- (concat docstring\r
- (if (string-match "\n?\n\\'" docstring)\r
- (if (< (- (match-end 0) (match-beginning 0)) 2) "\n" "")\r
- "\n\n")\r
- (if (and (stringp arglist)\r
- (string-match "\\`([^ ]+\\(.*\\))\\'" arglist))\r
- (concat "(fn" (match-string 1 arglist) ")")\r
- (format "%S" (help-make-usage 'fn arglist))))))\r
-\r
-(defun help-function-arglist (def)\r
- ;; Handle symbols aliased to other symbols.\r
- (if (and (symbolp def) (fboundp def)) (setq def (indirect-function def)))\r
- ;; If definition is a macro, find the function inside it.\r
- (if (eq (car-safe def) 'macro) (setq def (cdr def)))\r
- (cond\r
- ((byte-code-function-p def) (aref def 0))\r
- ((eq (car-safe def) 'lambda) (nth 1 def))\r
- ((and (eq (car-safe def) 'autoload) (not (eq (nth 4 def) 'keymap)))\r
- "[Arg list not available until function definition is loaded.]")\r
- (t t)))\r
-\r
-(defun help-make-usage (function arglist)\r
- (cons (if (symbolp function) function 'anonymous)\r
- (mapcar (lambda (arg)\r
- (if (not (symbolp arg))\r
- (if (and (consp arg) (symbolp (car arg)))\r
- ;; CL style default values for optional args.\r
- (cons (intern (upcase (symbol-name (car arg))))\r
- (cdr arg))\r
- arg)\r
- (let ((name (symbol-name arg)))\r
- (if (string-match "\\`&" name) arg\r
- (intern (upcase name))))))\r
- arglist)))\r
-\r
-;; Could be this, if we make symbol-file do the work below.\r
-;; (defun help-C-file-name (subr-or-var kind)\r
-;; "Return the name of the C file where SUBR-OR-VAR is defined.\r
-;; KIND should be `var' for a variable or `subr' for a subroutine."\r
-;; (symbol-file (if (symbolp subr-or-var) subr-or-var\r
-;; (subr-name subr-or-var))\r
-;; (if (eq kind 'var) 'defvar 'defun)))\r
-;;;###autoload\r
-(defun help-C-file-name (subr-or-var kind)\r
- "Return the name of the C file where SUBR-OR-VAR is defined.\r
-KIND should be `var' for a variable or `subr' for a subroutine."\r
- (let ((docbuf (get-buffer-create " *DOC*"))\r
- (name (if (eq 'var kind)\r
- (concat "V" (symbol-name subr-or-var))\r
- (concat "F" (subr-name subr-or-var)))))\r
- (with-current-buffer docbuf\r
- (goto-char (point-min))\r
- (if (eobp)\r
- (insert-file-contents-literally\r
- (expand-file-name internal-doc-file-name doc-directory)))\r
- (let ((file (catch 'loop\r
- (while t\r
- (let ((pnt (search-forward (concat "\1f" name "\n"))))\r
- (re-search-backward "\1fS\\(.*\\)")\r
- (let ((file (match-string 1)))\r
- (if (member file build-files)\r
- (throw 'loop file)\r
- (goto-char pnt))))))))\r
- (if (string-match "^ns.*\\(\\.o\\|obj\\)\\'" file)\r
- (setq file (replace-match ".m" t t file 1))\r
- (if (string-match "\\.\\(o\\|obj\\)\\'" file)\r
- (setq file (replace-match ".c" t t file))))\r
- (if (string-match "\\.\\(c\\|m\\)\\'" file)\r
- (concat "src/" file)\r
- file)))))\r
-\r
-(defface help-argument-name '((((supports :slant italic)) :inherit italic))\r
- "Face to highlight argument names in *Help* buffers."\r
- :group 'help)\r
-\r
-(defun help-default-arg-highlight (arg)\r
- "Default function to highlight arguments in *Help* buffers.\r
-It returns ARG in face `help-argument-name'; ARG is also\r
-downcased if it displays differently than the default\r
-face (according to `face-differs-from-default-p')."\r
- (propertize (if (face-differs-from-default-p 'help-argument-name)\r
- (downcase arg)\r
- arg)\r
- 'face 'help-argument-name))\r
-\r
-(defun help-do-arg-highlight (doc args)\r
- (with-syntax-table (make-syntax-table emacs-lisp-mode-syntax-table)\r
- (modify-syntax-entry ?\- "w")\r
- (dolist (arg args doc)\r
- (setq doc (replace-regexp-in-string\r
- ;; This is heuristic, but covers all common cases\r
- ;; except ARG1-ARG2\r
- (concat "\\<" ; beginning of word\r
- "\\(?:[a-z-]*-\\)?" ; for xxx-ARG\r
- "\\("\r
- (regexp-quote arg)\r
- "\\)"\r
- "\\(?:es\\|s\\|th\\)?" ; for ARGth, ARGs\r
- "\\(?:-[a-z0-9-]+\\)?" ; for ARG-xxx, ARG-n\r
- "\\(?:-[{([<`\"].*?\\)?"; for ARG-{x}, (x), <x>, [x], `x'\r
- "\\>") ; end of word\r
- (help-default-arg-highlight arg)\r
- doc t t 1)))))\r
-\r
-(defun help-highlight-arguments (usage doc &rest args)\r
- (when usage\r
- (with-temp-buffer\r
- (insert usage)\r
- (goto-char (point-min))\r
- (let ((case-fold-search nil)\r
- (next (not (or args (looking-at "\\["))))\r
- (opt nil))\r
- ;; Make a list of all arguments\r
- (skip-chars-forward "^ ")\r
- (while next\r
- (or opt (not (looking-at " &")) (setq opt t))\r
- (if (not (re-search-forward " \\([\\[(]*\\)\\([^] &)\.]+\\)" nil t))\r
- (setq next nil)\r
- (setq args (cons (match-string 2) args))\r
- (when (and opt (string= (match-string 1) "("))\r
- ;; A pesky CL-style optional argument with default value,\r
- ;; so let's skip over it\r
- (search-backward "(")\r
- (goto-char (scan-sexps (point) 1)))))\r
- ;; Highlight aguments in the USAGE string\r
- (setq usage (help-do-arg-highlight (buffer-string) args))\r
- ;; Highlight arguments in the DOC string\r
- (setq doc (and doc (help-do-arg-highlight doc args))))))\r
- ;; Return value is like the one from help-split-fundoc, but highlighted\r
- (cons usage doc))\r
-\r
-;; The following function was compiled from the former functions\r
-;; `describe-simplify-lib-file-name' and `find-source-lisp-file' with\r
-;; some excerpts from `describe-function-1' and `describe-variable'.\r
-;; The only additional twists provided are (1) locate the defining file\r
-;; for autoloaded functions, and (2) give preference to files in the\r
-;; "install directory" (directories found via `load-path') rather than\r
-;; to files in the "compile directory" (directories found by searching\r
-;; the loaddefs.el file). We autoload it because it's also used by\r
-;; `describe-face' (instead of `describe-simplify-lib-file-name').\r
-\r
-;;;###autoload\r
-(defun find-lisp-object-file-name (object type)\r
- "Guess the file that defined the Lisp object OBJECT, of type TYPE.\r
-OBJECT should be a symbol associated with a function, variable, or face;\r
- alternatively, it can be a function definition.\r
-If TYPE is `variable', search for a variable definition.\r
-If TYPE is `face', search for a face definition.\r
-If TYPE is the value returned by `symbol-function' for a function symbol,\r
- search for a function definition.\r
-\r
-The return value is the absolute name of a readable file where OBJECT is\r
-defined. If several such files exist, preference is given to a file\r
-found via `load-path'. The return value can also be `C-source', which\r
-means that OBJECT is a function or variable defined in C. If no\r
-suitable file is found, return nil."\r
- (let* ((autoloaded (eq (car-safe type) 'autoload))\r
- (file-name (or (and autoloaded (nth 1 type))\r
- (symbol-file\r
- object (if (memq type (list 'defvar 'defface))\r
- type\r
- 'defun)))))\r
- (cond\r
- (autoloaded\r
- ;; An autoloaded function: Locate the file since `symbol-function'\r
- ;; has only returned a bare string here.\r
- (setq file-name\r
- (locate-file file-name load-path '(".el" ".elc") 'readable)))\r
- ((and (stringp file-name)\r
- (string-match "[.]*loaddefs.el\\'" file-name))\r
- ;; An autoloaded variable or face. Visit loaddefs.el in a buffer\r
- ;; and try to extract the defining file. The following form is\r
- ;; from `describe-function-1' and `describe-variable'.\r
- (let ((location\r
- (condition-case nil\r
- (find-function-search-for-symbol object nil file-name)\r
- (error nil))))\r
- (when location\r
- (with-current-buffer (car location)\r
- (goto-char (cdr location))\r
- (when (re-search-backward\r
- "^;;; Generated autoloads from \\(.*\\)" nil t)\r
- (setq file-name\r
- (locate-file\r
- (match-string-no-properties 1)\r
- load-path nil 'readable))))))))\r
-\r
- (cond\r
- ((and (not file-name) (subrp type))\r
- ;; A built-in function. The form is from `describe-function-1'.\r
- (if (get-buffer " *DOC*")\r
- (help-C-file-name type 'subr)\r
- 'C-source))\r
- ((and (not file-name) (symbolp object)\r
- (integerp (get object 'variable-documentation)))\r
- ;; A variable defined in C. The form is from `describe-variable'.\r
- (if (get-buffer " *DOC*")\r
- (help-C-file-name object 'var)\r
- 'C-source))\r
- ((not (stringp file-name))\r
- ;; If we don't have a file-name string by now, we lost.\r
- nil)\r
- ((let ((lib-name\r
- (if (string-match "[.]elc\\'" file-name)\r
- (substring-no-properties file-name 0 -1)\r
- file-name)))\r
- ;; When the Elisp source file can be found in the install\r
- ;; directory return the name of that file - `file-name' should\r
- ;; have become an absolute file name ny now.\r
- (or (and (file-readable-p lib-name) lib-name)\r
- ;; The library might be compressed.\r
- (and (file-readable-p (concat lib-name ".gz")) lib-name))))\r
- ((let* ((lib-name (file-name-nondirectory file-name))\r
- ;; The next form is from `describe-simplify-lib-file-name'.\r
- (file-name\r
- ;; Try converting the absolute file name to a library\r
- ;; name, convert that back to a file name and see if we\r
- ;; get the original one. If so, they are equivalent.\r
- (if (equal file-name (locate-file lib-name load-path '("")))\r
- (if (string-match "[.]elc\\'" lib-name)\r
- (substring-no-properties lib-name 0 -1)\r
- lib-name)\r
- file-name))\r
- ;; The next three forms are from `find-source-lisp-file'.\r
- (elc-file (locate-file\r
- (concat file-name\r
- (if (string-match "\\.el\\'" file-name)\r
- "c"\r
- ".elc"))\r
- load-path nil 'readable))\r
- (str (when elc-file\r
- (with-temp-buffer\r
- (insert-file-contents-literally elc-file nil 0 256)\r
- (buffer-string))))\r
- (src-file (and str\r
- (string-match ";;; from file \\(.*\\.el\\)" str)\r
- (match-string 1 str))))\r
- (and src-file (file-readable-p src-file) src-file))))))\r
-\r
-(declare-function ad-get-advice-info "advice" (function))\r
-\r
-;;;###autoload\r
-(defun describe-function-1 (function)\r
- (let* ((advised (and (symbolp function) (featurep 'advice)\r
- (ad-get-advice-info function)))\r
- ;; If the function is advised, use the symbol that has the\r
- ;; real definition, if that symbol is already set up.\r
- (real-function\r
- (or (and advised\r
- (let ((origname (cdr (assq 'origname advised))))\r
- (and (fboundp origname) origname)))\r
- function))\r
- ;; Get the real definition.\r
- (def (if (symbolp real-function)\r
- (symbol-function real-function)\r
- function))\r
- file-name string\r
- (beg (if (commandp def) "an interactive " "a "))\r
- (pt1 (with-current-buffer (help-buffer) (point)))\r
- errtype)\r
- (setq string\r
- (cond ((or (stringp def)\r
- (vectorp def))\r
- "a keyboard macro")\r
- ((subrp def)\r
- (if (eq 'unevalled (cdr (subr-arity def)))\r
- (concat beg "special form")\r
- (concat beg "built-in function")))\r
- ((byte-code-function-p def)\r
- (concat beg "compiled Lisp function"))\r
- ((symbolp def)\r
- (while (and (fboundp def)\r
- (symbolp (symbol-function def)))\r
- (setq def (symbol-function def)))\r
- ;; Handle (defalias 'foo 'bar), where bar is undefined.\r
- (or (fboundp def) (setq errtype 'alias))\r
- (format "an alias for `%s'" def))\r
- ((eq (car-safe def) 'lambda)\r
- (concat beg "Lisp function"))\r
- ((eq (car-safe def) 'macro)\r
- "a Lisp macro")\r
- ((eq (car-safe def) 'autoload)\r
- (format "%s autoloaded %s"\r
- (if (commandp def) "an interactive" "an")\r
- (if (eq (nth 4 def) 'keymap) "keymap"\r
- (if (nth 4 def) "Lisp macro" "Lisp function"))))\r
- ((keymapp def)\r
- (let ((is-full nil)\r
- (elts (cdr-safe def)))\r
- (while elts\r
- (if (char-table-p (car-safe elts))\r
- (setq is-full t\r
- elts nil))\r
- (setq elts (cdr-safe elts)))\r
- (if is-full\r
- "a full keymap"\r
- "a sparse keymap")))\r
- (t "")))\r
- (princ string)\r
- (if (eq errtype 'alias)\r
- (princ ",\nwhich is not defined. Please make a bug report.")\r
- (with-current-buffer standard-output\r
- (save-excursion\r
- (save-match-data\r
- (when (re-search-backward "alias for `\\([^`']+\\)'" nil t)\r
- (help-xref-button 1 'help-function def)))))\r
-\r
- (setq file-name (find-lisp-object-file-name function def))\r
- (when file-name\r
- (princ " in `")\r
- ;; We used to add .el to the file name,\r
- ;; but that's completely wrong when the user used load-file.\r
- (princ (if (eq file-name 'C-source) "C source code" file-name))\r
- (princ "'")\r
- ;; Make a hyperlink to the library.\r
- (with-current-buffer standard-output\r
- (save-excursion\r
- (re-search-backward "`\\([^`']+\\)'" nil t)\r
- (help-xref-button 1 'help-function-def real-function file-name))))\r
- (princ ".")\r
- (with-current-buffer (help-buffer)\r
- (fill-region-as-paragraph (save-excursion (goto-char pt1) (forward-line 0) (point))\r
- (point)))\r
- (terpri)(terpri)\r
- (when (commandp function)\r
- (let ((pt2 (with-current-buffer (help-buffer) (point))))\r
- (if (and (eq function 'self-insert-command)\r
- (eq (key-binding "a") 'self-insert-command)\r
- (eq (key-binding "b") 'self-insert-command)\r
- (eq (key-binding "c") 'self-insert-command))\r
- (princ "It is bound to many ordinary text characters.\n")\r
- (let* ((remapped (command-remapping function))\r
- (keys (where-is-internal\r
- (or remapped function) overriding-local-map nil nil))\r
- non-modified-keys)\r
- ;; Which non-control non-meta keys run this command?\r
- (dolist (key keys)\r
- (if (member (event-modifiers (aref key 0)) '(nil (shift)))\r
- (push key non-modified-keys)))\r
- (when remapped\r
- (princ "It is remapped to `")\r
- (princ (symbol-name remapped))\r
- (princ "'"))\r
-\r
- (when keys\r
- (princ (if remapped ", which is bound to " "It is bound to "))\r
- ;; If lots of ordinary text characters run this command,\r
- ;; don't mention them one by one.\r
- (if (< (length non-modified-keys) 10)\r
- (princ (mapconcat 'key-description keys ", "))\r
- (dolist (key non-modified-keys)\r
- (setq keys (delq key keys)))\r
- (if keys\r
- (progn\r
- (princ (mapconcat 'key-description keys ", "))\r
- (princ ", and many ordinary text characters"))\r
- (princ "many ordinary text characters"))))\r
- (when (or remapped keys non-modified-keys)\r
- (princ ".")\r
- (terpri))))\r
- (with-current-buffer (help-buffer) (fill-region-as-paragraph pt2 (point)))\r
- (terpri)))\r
- (let* ((arglist (help-function-arglist def))\r
- (doc (documentation function))\r
- (usage (help-split-fundoc doc function)))\r
- (with-current-buffer standard-output\r
- ;; If definition is a keymap, skip arglist note.\r
- (unless (keymapp function)\r
- (let* ((use (cond\r
- (usage (setq doc (cdr usage)) (car usage))\r
- ((listp arglist)\r
- (format "%S" (help-make-usage function arglist)))\r
- ((stringp arglist) arglist)\r
- ;; Maybe the arglist is in the docstring of a symbol\r
- ;; this one is aliased to.\r
- ((let ((fun real-function))\r
- (while (and (symbolp fun)\r
- (setq fun (symbol-function fun))\r
- (not (setq usage (help-split-fundoc\r
- (documentation fun)\r
- function)))))\r
- usage)\r
- (car usage))\r
- ((or (stringp def)\r
- (vectorp def))\r
- (format "\nMacro: %s" (format-kbd-macro def)))\r
- (t "[Missing arglist. Please make a bug report.]")))\r
- (high (help-highlight-arguments use doc)))\r
- (let ((fill-begin (point)))\r
- (insert (car high) "\n")\r
- (fill-region fill-begin (point)))\r
- (setq doc (cdr high))))\r
- (let* ((obsolete (and\r
- ;; function might be a lambda construct.\r
- (symbolp function)\r
- (get function 'byte-obsolete-info)))\r
- (use (car obsolete)))\r
- (when obsolete\r
- (princ "\nThis function is obsolete")\r
- (when (nth 2 obsolete)\r
- (insert (format " since %s" (nth 2 obsolete))))\r
- (insert (cond ((stringp use) (concat ";\n" use))\r
- (use (format ";\nuse `%s' instead." use))\r
- (t "."))\r
- "\n"))\r
- (insert "\n"\r
- (or doc "Not documented."))))))))\r
-\r
-\f\r
-;; Variables\r
-\r
-;;;###autoload\r
-(defun variable-at-point (&optional any-symbol)\r
- "Return the bound variable symbol found at or before point.\r
-Return 0 if there is no such symbol.\r
-If ANY-SYMBOL is non-nil, don't insist the symbol be bound."\r
- (with-syntax-table emacs-lisp-mode-syntax-table\r
- (or (condition-case ()\r
- (save-excursion\r
- (or (not (zerop (skip-syntax-backward "_w")))\r
- (eq (char-syntax (following-char)) ?w)\r
- (eq (char-syntax (following-char)) ?_)\r
- (forward-sexp -1))\r
- (skip-chars-forward "'")\r
- (let ((obj (read (current-buffer))))\r
- (and (symbolp obj) (boundp obj) obj)))\r
- (error nil))\r
- (let* ((str (find-tag-default))\r
- (sym (if str (intern-soft str))))\r
- (if (and sym (or any-symbol (boundp sym)))\r
- sym\r
- (save-match-data\r
- (when (and str (string-match "\\`\\W*\\(.*?\\)\\W*\\'" str))\r
- (setq sym (intern-soft (match-string 1 str)))\r
- (and (or any-symbol (boundp sym)) sym)))))\r
- 0)))\r
-\r
-(defun describe-variable-custom-version-info (variable)\r
- (let ((custom-version (get variable 'custom-version))\r
- (cpv (get variable 'custom-package-version))\r
- (output nil))\r
- (if custom-version\r
- (setq output\r
- (format "This variable was introduced, or its default value was changed, in\nversion %s of Emacs.\n"\r
- custom-version))\r
- (when cpv\r
- (let* ((package (car-safe cpv))\r
- (version (if (listp (cdr-safe cpv))\r
- (car (cdr-safe cpv))\r
- (cdr-safe cpv)))\r
- (pkg-versions (assq package customize-package-emacs-version-alist))\r
- (emacsv (cdr (assoc version pkg-versions))))\r
- (if (and package version)\r
- (setq output\r
- (format (concat "This variable was introduced, or its default value was changed, in\nversion %s of the %s package"\r
- (if emacsv\r
- (format " that is part of Emacs %s" emacsv))\r
- ".\n")\r
- version package))))))\r
- output))\r
-\r
-;;;###autoload\r
-(defun describe-variable (variable &optional buffer frame)\r
- "Display the full documentation of VARIABLE (a symbol).\r
-Returns the documentation as a string, also.\r
-If VARIABLE has a buffer-local value in BUFFER or FRAME\r
-\(default to the current buffer and current frame),\r
-it is displayed along with the global value."\r
- (interactive\r
- (let ((v (variable-at-point))\r
- (enable-recursive-minibuffers t)\r
- val)\r
- (setq val (completing-read (if (symbolp v)\r
- (format\r
- "Describe variable (default %s): " v)\r
- "Describe variable: ")\r
- obarray\r
- '(lambda (vv)\r
- (or (boundp vv)\r
- (get vv 'variable-documentation)))\r
- t nil nil\r
- (if (symbolp v) (symbol-name v))))\r
- (list (if (equal val "")\r
- v (intern val)))))\r
- (let (file-name)\r
- (unless (buffer-live-p buffer) (setq buffer (current-buffer)))\r
- (unless (frame-live-p frame) (setq frame (selected-frame)))\r
- (if (not (symbolp variable))\r
- (message "You did not specify a variable")\r
- (save-excursion\r
- (let ((valvoid (not (with-current-buffer buffer (boundp variable))))\r
- val val-start-pos locus)\r
- ;; Extract the value before setting up the output buffer,\r
- ;; in case `buffer' *is* the output buffer.\r
- (unless valvoid\r
- (with-selected-frame frame\r
- (with-current-buffer buffer\r
- (setq val (symbol-value variable)\r
- locus (variable-binding-locus variable)))))\r
- (help-setup-xref (list #'describe-variable variable buffer)\r
- (interactive-p))\r
- (with-help-window (help-buffer)\r
- (with-current-buffer buffer\r
- (prin1 variable)\r
- (setq file-name (find-lisp-object-file-name variable 'defvar))\r
-\r
- (if file-name\r
- (progn\r
- (princ " is a variable defined in `")\r
- (princ (if (eq file-name 'C-source) "C source code" file-name))\r
- (princ "'.\n")\r
- (with-current-buffer standard-output\r
- (save-excursion\r
- (re-search-backward "`\\([^`']+\\)'" nil t)\r
- (help-xref-button 1 'help-variable-def\r
- variable file-name)))\r
- (if valvoid\r
- (princ "It is void as a variable.")\r
- (princ "Its ")))\r
- (if valvoid\r
- (princ " is void as a variable.")\r
- (princ "'s "))))\r
- (if valvoid\r
- nil\r
- (with-current-buffer standard-output\r
- (setq val-start-pos (point))\r
- (princ "value is ")\r
- (terpri)\r
- (let ((from (point)))\r
- (pp val)\r
- ;; Hyperlinks in variable's value are quite frequently\r
- ;; inappropriate e.g C-h v <RET> features <RET>\r
- ;; (help-xref-on-pp from (point))\r
- (if (< (point) (+ from 20))\r
- (delete-region (1- from) from)))))\r
- (terpri)\r
-\r
- (when locus\r
- (if (bufferp locus)\r
- (princ (format "%socal in buffer %s; "\r
- (if (get variable 'permanent-local)\r
- "Permanently l" "L")\r
- (buffer-name)))\r
- (princ (format "It is a frame-local variable; ")))\r
- (if (not (default-boundp variable))\r
- (princ "globally void")\r
- (let ((val (default-value variable)))\r
- (with-current-buffer standard-output\r
- (princ "global value is ")\r
- (terpri)\r
- ;; Fixme: pp can take an age if you happen to\r
- ;; ask for a very large expression. We should\r
- ;; probably print it raw once and check it's a\r
- ;; sensible size before prettyprinting. -- fx\r
- (let ((from (point)))\r
- (pp val)\r
- ;; See previous comment for this function.\r
- ;; (help-xref-on-pp from (point))\r
- (if (< (point) (+ from 20))\r
- (delete-region (1- from) from))))))\r
- (terpri))\r
-\r
- ;; If the value is large, move it to the end.\r
- (with-current-buffer standard-output\r
- (when (> (count-lines (point-min) (point-max)) 10)\r
- ;; Note that setting the syntax table like below\r
- ;; makes forward-sexp move over a `'s' at the end\r
- ;; of a symbol.\r
- (set-syntax-table emacs-lisp-mode-syntax-table)\r
- (goto-char val-start-pos)\r
- ;; The line below previously read as\r
- ;; (delete-region (point) (progn (end-of-line) (point)))\r
- ;; which suppressed display of the buffer local value for\r
- ;; large values.\r
- (when (looking-at "value is") (replace-match ""))\r
- (save-excursion\r
- (insert "\n\nValue:")\r
- (set (make-local-variable 'help-button-cache)\r
- (point-marker)))\r
- (insert "value is shown ")\r
- (insert-button "below"\r
- 'action help-button-cache\r
- 'follow-link t\r
- 'help-echo "mouse-2, RET: show value")\r
- (insert ".\n")))\r
- (terpri)\r
-\r
- (let* ((alias (condition-case nil\r
- (indirect-variable variable)\r
- (error variable)))\r
- (obsolete (get variable 'byte-obsolete-variable))\r
- (use (car obsolete))\r
- (safe-var (get variable 'safe-local-variable))\r
- (doc (or (documentation-property variable 'variable-documentation)\r
- (documentation-property alias 'variable-documentation)))\r
- (extra-line nil))\r
- ;; Add a note for variables that have been make-var-buffer-local.\r
- (when (and (local-variable-if-set-p variable)\r
- (or (not (local-variable-p variable))\r
- (with-temp-buffer\r
- (local-variable-if-set-p variable))))\r
- (setq extra-line t)\r
- (princ " Automatically becomes buffer-local when set in any fashion.\n"))\r
-\r
- ;; Mention if it's an alias\r
- (unless (eq alias variable)\r
- (setq extra-line t)\r
- (princ (format " This variable is an alias for `%s'.\n" alias)))\r
-\r
- (when obsolete\r
- (setq extra-line t)\r
- (princ " This variable is obsolete")\r
- (if (cdr obsolete) (princ (format " since %s" (cdr obsolete))))\r
- (princ (cond ((stringp use) (concat ";\n " use))\r
- (use (format ";\n use `%s' instead." (car obsolete)))\r
- (t ".")))\r
- (terpri))\r
- (when safe-var\r
- (setq extra-line t)\r
- (princ " This variable is safe as a file local variable ")\r
- (princ "if its value\n satisfies the predicate ")\r
- (princ (if (byte-code-function-p safe-var)\r
- "which is byte-compiled expression.\n"\r
- (format "`%s'.\n" safe-var))))\r
-\r
- (if extra-line (terpri))\r
- (princ "Documentation:\n")\r
- (with-current-buffer standard-output\r
- (insert (or doc "Not documented as a variable."))))\r
-\r
- ;; Make a link to customize if this variable can be customized.\r
- (when (custom-variable-p variable)\r
- (let ((customize-label "customize"))\r
- (terpri)\r
- (terpri)\r
- (princ (concat "You can " customize-label " this variable."))\r
- (with-current-buffer standard-output\r
- (save-excursion\r
- (re-search-backward\r
- (concat "\\(" customize-label "\\)") nil t)\r
- (help-xref-button 1 'help-customize-variable variable))))\r
- ;; Note variable's version or package version\r
- (let ((output (describe-variable-custom-version-info variable)))\r
- (when output\r
- (terpri)\r
- (terpri)\r
- (princ output))))\r
-\r
- (save-excursion\r
- (set-buffer standard-output)\r
- ;; Return the text we displayed.\r
- (buffer-string))))))))\r
-\r
-\r
-;;;###autoload\r
-(defun describe-syntax (&optional buffer)\r
- "Describe the syntax specifications in the syntax table of BUFFER.\r
-The descriptions are inserted in a help buffer, which is then displayed.\r
-BUFFER defaults to the current buffer."\r
- (interactive)\r
- (setq buffer (or buffer (current-buffer)))\r
- (help-setup-xref (list #'describe-syntax buffer) (interactive-p))\r
- (with-help-window (help-buffer)\r
- (let ((table (with-current-buffer buffer (syntax-table))))\r
- (with-current-buffer standard-output\r
- (describe-vector table 'internal-describe-syntax-value)\r
- (while (setq table (char-table-parent table))\r
- (insert "\nThe parent syntax table is:")\r
- (describe-vector table 'internal-describe-syntax-value))))))\r
-\r
-(defun help-describe-category-set (value)\r
- (insert (cond\r
- ((null value) "default")\r
- ((char-table-p value) "deeper char-table ...")\r
- (t (condition-case err\r
- (category-set-mnemonics value)\r
- (error "invalid"))))))\r
-\r
-;;;###autoload\r
-(defun describe-categories (&optional buffer)\r
- "Describe the category specifications in the current category table.\r
-The descriptions are inserted in a buffer, which is then displayed.\r
-If BUFFER is non-nil, then describe BUFFER's category table instead.\r
-BUFFER should be a buffer or a buffer name."\r
- (interactive)\r
- (setq buffer (or buffer (current-buffer)))\r
- (help-setup-xref (list #'describe-categories buffer) (interactive-p))\r
- (with-help-window (help-buffer)\r
- (let ((table (with-current-buffer buffer (category-table))))\r
- (with-current-buffer standard-output\r
- (describe-vector table 'help-describe-category-set)\r
- (let ((docs (char-table-extra-slot table 0)))\r
- (if (or (not (vectorp docs)) (/= (length docs) 95))\r
- (insert "Invalid first extra slot in this char table\n")\r
- (insert "Meanings of mnemonic characters are:\n")\r
- (dotimes (i 95)\r
- (let ((elt (aref docs i)))\r
- (when elt\r
- (insert (+ i ?\s) ": " elt "\n"))))\r
- (while (setq table (char-table-parent table))\r
- (insert "\nThe parent category table is:")\r
- (describe-vector table 'help-describe-category-set))))))))\r
-\r
-(provide 'help-fns)\r
-\r
-;; arch-tag: 9e10331c-ae81-4d13-965d-c4819aaab0b3\r
-;;; help-fns.el ends here\r
+;;; help-fns.el --- Complex help functions
+
+;; Copyright (C) 1985, 1986, 1993, 1994, 1998, 1999, 2000, 2001,
+;; 2002, 2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
+
+;; Maintainer: FSF
+;; Keywords: help, internal
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; This file contains those help commands which are complicated, and
+;; which may not be used in every session. For example
+;; `describe-function' will probably be heavily used when doing elisp
+;; programming, but not if just editing C files. Simpler help commands
+;; are in help.el
+
+;;; Code:
+
+(require 'help-mode)
+
+;; Functions
+
+;;;###autoload
+(defun describe-function (function)
+ "Display the full documentation of FUNCTION (a symbol)."
+ (interactive
+ (let ((fn (function-called-at-point))
+ (enable-recursive-minibuffers t)
+ val)
+ (setq val (completing-read (if fn
+ (format "Describe function (default %s): " fn)
+ "Describe function: ")
+ obarray 'fboundp t nil nil
+ (and fn (symbol-name fn))))
+ (list (if (equal val "")
+ fn (intern val)))))
+ (if (null function)
+ (message "You didn't specify a function")
+ (help-setup-xref (list #'describe-function function) (interactive-p))
+ (save-excursion
+ (with-help-window (help-buffer)
+ (prin1 function)
+ ;; Use " is " instead of a colon so that
+ ;; it is easier to get out the function name using forward-sexp.
+ (princ " is ")
+ (describe-function-1 function)
+ (with-current-buffer standard-output
+ ;; Return the text we displayed.
+ (buffer-string))))))
+
+(defun help-split-fundoc (docstring def)
+ "Split a function DOCSTRING into the actual doc and the usage info.
+Return (USAGE . DOC) or nil if there's no usage info.
+DEF is the function whose usage we're looking for in DOCSTRING."
+ ;; 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.
+ (when (and docstring (string-match "\n\n(fn\\(\\( .*\\)?)\\)\\'" docstring))
+ (cons (format "(%s%s"
+ ;; Replace `fn' with the actual function name.
+ (if (consp def) "anonymous" def)
+ (match-string 1 docstring))
+ (substring docstring 0 (match-beginning 0)))))
+
+(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 "Not documented"))
+ (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 (and (stringp arglist)
+ (string-match "\\`([^ ]+\\(.*\\))\\'" arglist))
+ (concat "(fn" (match-string 1 arglist) ")")
+ (format "%S" (help-make-usage 'fn arglist))))))
+
+(defun help-function-arglist (def)
+ ;; Handle symbols aliased to other symbols.
+ (if (and (symbolp def) (fboundp def)) (setq def (indirect-function def)))
+ ;; If definition is a macro, find the function inside it.
+ (if (eq (car-safe def) 'macro) (setq def (cdr def)))
+ (cond
+ ((byte-code-function-p def) (aref def 0))
+ ((eq (car-safe def) 'lambda) (nth 1 def))
+ ((and (eq (car-safe def) 'autoload) (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)
+ (if (not (symbolp arg))
+ (if (and (consp arg) (symbolp (car arg)))
+ ;; CL style default values for optional args.
+ (cons (intern (upcase (symbol-name (car arg))))
+ (cdr arg))
+ arg)
+ (let ((name (symbol-name arg)))
+ (if (string-match "\\`&" name) arg
+ (intern (upcase name))))))
+ arglist)))
+
+;; Could be this, if we make symbol-file do the work below.
+;; (defun help-C-file-name (subr-or-var kind)
+;; "Return the name of the C file where SUBR-OR-VAR is defined.
+;; KIND should be `var' for a variable or `subr' for a subroutine."
+;; (symbol-file (if (symbolp subr-or-var) subr-or-var
+;; (subr-name subr-or-var))
+;; (if (eq kind 'var) 'defvar 'defun)))
+;;;###autoload
+(defun help-C-file-name (subr-or-var kind)
+ "Return the name of the C file where SUBR-OR-VAR is defined.
+KIND should be `var' for a variable or `subr' for a subroutine."
+ (let ((docbuf (get-buffer-create " *DOC*"))
+ (name (if (eq 'var kind)
+ (concat "V" (symbol-name subr-or-var))
+ (concat "F" (subr-name subr-or-var)))))
+ (with-current-buffer docbuf
+ (goto-char (point-min))
+ (if (eobp)
+ (insert-file-contents-literally
+ (expand-file-name internal-doc-file-name doc-directory)))
+ (let ((file (catch 'loop
+ (while t
+ (let ((pnt (search-forward (concat "\1f" name "\n"))))
+ (re-search-backward "\1fS\\(.*\\)")
+ (let ((file (match-string 1)))
+ (if (member file build-files)
+ (throw 'loop file)
+ (goto-char pnt))))))))
+ (if (string-match "^ns.*\\(\\.o\\|obj\\)\\'" file)
+ (setq file (replace-match ".m" t t file 1))
+ (if (string-match "\\.\\(o\\|obj\\)\\'" file)
+ (setq file (replace-match ".c" t t file))))
+ (if (string-match "\\.\\(c\\|m\\)\\'" file)
+ (concat "src/" file)
+ file)))))
+
+(defface help-argument-name '((((supports :slant italic)) :inherit italic))
+ "Face to highlight argument names in *Help* buffers."
+ :group 'help)
+
+(defun help-default-arg-highlight (arg)
+ "Default function to highlight arguments in *Help* buffers.
+It returns ARG in face `help-argument-name'; ARG is also
+downcased if it displays differently than the default
+face (according to `face-differs-from-default-p')."
+ (propertize (if (face-differs-from-default-p 'help-argument-name)
+ (downcase arg)
+ arg)
+ 'face 'help-argument-name))
+
+(defun help-do-arg-highlight (doc args)
+ (with-syntax-table (make-syntax-table emacs-lisp-mode-syntax-table)
+ (modify-syntax-entry ?\- "w")
+ (dolist (arg args doc)
+ (setq doc (replace-regexp-in-string
+ ;; This is heuristic, but covers all common cases
+ ;; except ARG1-ARG2
+ (concat "\\<" ; beginning of word
+ "\\(?:[a-z-]*-\\)?" ; for xxx-ARG
+ "\\("
+ (regexp-quote arg)
+ "\\)"
+ "\\(?:es\\|s\\|th\\)?" ; for ARGth, ARGs
+ "\\(?:-[a-z0-9-]+\\)?" ; for ARG-xxx, ARG-n
+ "\\(?:-[{([<`\"].*?\\)?"; for ARG-{x}, (x), <x>, [x], `x'
+ "\\>") ; end of word
+ (help-default-arg-highlight arg)
+ doc t t 1)))))
+
+(defun help-highlight-arguments (usage doc &rest args)
+ (when usage
+ (with-temp-buffer
+ (insert usage)
+ (goto-char (point-min))
+ (let ((case-fold-search nil)
+ (next (not (or args (looking-at "\\["))))
+ (opt nil))
+ ;; Make a list of all arguments
+ (skip-chars-forward "^ ")
+ (while next
+ (or opt (not (looking-at " &")) (setq opt t))
+ (if (not (re-search-forward " \\([\\[(]*\\)\\([^] &)\.]+\\)" nil t))
+ (setq next nil)
+ (setq args (cons (match-string 2) args))
+ (when (and opt (string= (match-string 1) "("))
+ ;; A pesky CL-style optional argument with default value,
+ ;; so let's skip over it
+ (search-backward "(")
+ (goto-char (scan-sexps (point) 1)))))
+ ;; Highlight aguments in the USAGE string
+ (setq usage (help-do-arg-highlight (buffer-string) args))
+ ;; Highlight arguments in the DOC string
+ (setq doc (and doc (help-do-arg-highlight doc args))))))
+ ;; Return value is like the one from help-split-fundoc, but highlighted
+ (cons usage doc))
+
+;; The following function was compiled from the former functions
+;; `describe-simplify-lib-file-name' and `find-source-lisp-file' with
+;; some excerpts from `describe-function-1' and `describe-variable'.
+;; The only additional twists provided are (1) locate the defining file
+;; for autoloaded functions, and (2) give preference to files in the
+;; "install directory" (directories found via `load-path') rather than
+;; to files in the "compile directory" (directories found by searching
+;; the loaddefs.el file). We autoload it because it's also used by
+;; `describe-face' (instead of `describe-simplify-lib-file-name').
+
+;;;###autoload
+(defun find-lisp-object-file-name (object type)
+ "Guess the file that defined the Lisp object OBJECT, of type TYPE.
+OBJECT should be a symbol associated with a function, variable, or face;
+ alternatively, it can be a function definition.
+If TYPE is `variable', search for a variable definition.
+If TYPE is `face', search for a face definition.
+If TYPE is the value returned by `symbol-function' for a function symbol,
+ search for a function definition.
+
+The return value is the absolute name of a readable file where OBJECT is
+defined. If several such files exist, preference is given to a file
+found via `load-path'. The return value can also be `C-source', which
+means that OBJECT is a function or variable defined in C. If no
+suitable file is found, return nil."
+ (let* ((autoloaded (eq (car-safe type) 'autoload))
+ (file-name (or (and autoloaded (nth 1 type))
+ (symbol-file
+ object (if (memq type (list 'defvar 'defface))
+ type
+ 'defun)))))
+ (cond
+ (autoloaded
+ ;; An autoloaded function: Locate the file since `symbol-function'
+ ;; has only returned a bare string here.
+ (setq file-name
+ (locate-file file-name load-path '(".el" ".elc") 'readable)))
+ ((and (stringp file-name)
+ (string-match "[.]*loaddefs.el\\'" file-name))
+ ;; An autoloaded variable or face. Visit loaddefs.el in a buffer
+ ;; and try to extract the defining file. The following form is
+ ;; from `describe-function-1' and `describe-variable'.
+ (let ((location
+ (condition-case nil
+ (find-function-search-for-symbol object nil file-name)
+ (error nil))))
+ (when location
+ (with-current-buffer (car location)
+ (goto-char (cdr location))
+ (when (re-search-backward
+ "^;;; Generated autoloads from \\(.*\\)" nil t)
+ (setq file-name
+ (locate-file
+ (match-string-no-properties 1)
+ load-path nil 'readable))))))))
+
+ (cond
+ ((and (not file-name) (subrp type))
+ ;; A built-in function. The form is from `describe-function-1'.
+ (if (get-buffer " *DOC*")
+ (help-C-file-name type 'subr)
+ 'C-source))
+ ((and (not file-name) (symbolp object)
+ (integerp (get object 'variable-documentation)))
+ ;; A variable defined in C. The form is from `describe-variable'.
+ (if (get-buffer " *DOC*")
+ (help-C-file-name object 'var)
+ 'C-source))
+ ((not (stringp file-name))
+ ;; If we don't have a file-name string by now, we lost.
+ nil)
+ ((let ((lib-name
+ (if (string-match "[.]elc\\'" file-name)
+ (substring-no-properties file-name 0 -1)
+ file-name)))
+ ;; When the Elisp source file can be found in the install
+ ;; directory return the name of that file - `file-name' should
+ ;; have become an absolute file name ny now.
+ (or (and (file-readable-p lib-name) lib-name)
+ ;; The library might be compressed.
+ (and (file-readable-p (concat lib-name ".gz")) lib-name))))
+ ((let* ((lib-name (file-name-nondirectory file-name))
+ ;; The next form is from `describe-simplify-lib-file-name'.
+ (file-name
+ ;; Try converting the absolute file name to a library
+ ;; name, convert that back to a file name and see if we
+ ;; get the original one. If so, they are equivalent.
+ (if (equal file-name (locate-file lib-name load-path '("")))
+ (if (string-match "[.]elc\\'" lib-name)
+ (substring-no-properties lib-name 0 -1)
+ lib-name)
+ file-name))
+ ;; The next three forms are from `find-source-lisp-file'.
+ (elc-file (locate-file
+ (concat file-name
+ (if (string-match "\\.el\\'" file-name)
+ "c"
+ ".elc"))
+ load-path nil 'readable))
+ (str (when elc-file
+ (with-temp-buffer
+ (insert-file-contents-literally elc-file nil 0 256)
+ (buffer-string))))
+ (src-file (and str
+ (string-match ";;; from file \\(.*\\.el\\)" str)
+ (match-string 1 str))))
+ (and src-file (file-readable-p src-file) src-file))))))
+
+(declare-function ad-get-advice-info "advice" (function))
+
+;;;###autoload
+(defun describe-function-1 (function)
+ (let* ((advised (and (symbolp function) (featurep 'advice)
+ (ad-get-advice-info 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
+ (let ((origname (cdr (assq 'origname advised))))
+ (and (fboundp origname) origname)))
+ function))
+ ;; Get the real definition.
+ (def (if (symbolp real-function)
+ (symbol-function real-function)
+ function))
+ file-name string
+ (beg (if (commandp def) "an interactive " "a "))
+ (pt1 (with-current-buffer (help-buffer) (point)))
+ errtype)
+ (setq string
+ (cond ((or (stringp def)
+ (vectorp def))
+ "a keyboard macro")
+ ((subrp def)
+ (if (eq 'unevalled (cdr (subr-arity def)))
+ (concat beg "special form")
+ (concat beg "built-in function")))
+ ((byte-code-function-p def)
+ (concat beg "compiled Lisp function"))
+ ((symbolp def)
+ (while (and (fboundp def)
+ (symbolp (symbol-function def)))
+ (setq def (symbol-function def)))
+ ;; Handle (defalias 'foo 'bar), where bar is undefined.
+ (or (fboundp def) (setq errtype 'alias))
+ (format "an alias for `%s'" def))
+ ((eq (car-safe def) 'lambda)
+ (concat beg "Lisp function"))
+ ((eq (car-safe def) 'macro)
+ "a Lisp macro")
+ ((eq (car-safe def) 'autoload)
+ (format "%s autoloaded %s"
+ (if (commandp def) "an interactive" "an")
+ (if (eq (nth 4 def) 'keymap) "keymap"
+ (if (nth 4 def) "Lisp macro" "Lisp function"))))
+ ((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)))
+ (if is-full
+ "a full keymap"
+ "a sparse keymap")))
+ (t "")))
+ (princ string)
+ (if (eq errtype 'alias)
+ (princ ",\nwhich is not defined. Please make a bug report.")
+ (with-current-buffer standard-output
+ (save-excursion
+ (save-match-data
+ (when (re-search-backward "alias for `\\([^`']+\\)'" nil t)
+ (help-xref-button 1 'help-function def)))))
+
+ (setq file-name (find-lisp-object-file-name function def))
+ (when file-name
+ (princ " in `")
+ ;; We used to add .el to the file name,
+ ;; but that's completely wrong when the user used load-file.
+ (princ (if (eq file-name 'C-source)
+ "C source code"
+ (file-name-nondirectory file-name)))
+ (princ "'")
+ ;; Make a hyperlink to the library.
+ (with-current-buffer standard-output
+ (save-excursion
+ (re-search-backward "`\\([^`']+\\)'" nil t)
+ (help-xref-button 1 'help-function-def real-function file-name))))
+ (princ ".")
+ (with-current-buffer (help-buffer)
+ (fill-region-as-paragraph (save-excursion (goto-char pt1) (forward-line 0) (point))
+ (point)))
+ (terpri)(terpri)
+ (when (commandp function)
+ (let ((pt2 (with-current-buffer (help-buffer) (point)))
+ (remapped (command-remapping function)))
+ (unless (memq remapped '(ignore undefined))
+ (let ((keys (where-is-internal
+ (or remapped function) overriding-local-map nil nil))
+ non-modified-keys)
+ (if (and (eq function 'self-insert-command)
+ (vectorp (car-safe keys))
+ (consp (aref (car keys) 0)))
+ (princ "It is bound to many ordinary text characters.\n")
+ ;; Which non-control non-meta keys run this command?
+ (dolist (key keys)
+ (if (member (event-modifiers (aref key 0)) '(nil (shift)))
+ (push key non-modified-keys)))
+ (when remapped
+ (princ "It is remapped to `")
+ (princ (symbol-name remapped))
+ (princ "'"))
+
+ (when keys
+ (princ (if remapped ", which is bound to " "It is bound to "))
+ ;; If lots of ordinary text characters run this command,
+ ;; don't mention them one by one.
+ (if (< (length non-modified-keys) 10)
+ (princ (mapconcat 'key-description keys ", "))
+ (dolist (key non-modified-keys)
+ (setq keys (delq key keys)))
+ (if keys
+ (progn
+ (princ (mapconcat 'key-description keys ", "))
+ (princ ", and many ordinary text characters"))
+ (princ "many ordinary text characters"))))
+ (when (or remapped keys non-modified-keys)
+ (princ ".")
+ (terpri)))))
+
+ (with-current-buffer (help-buffer)
+ (fill-region-as-paragraph pt2 (point))
+ (unless (looking-back "\n\n")
+ (terpri)))))
+ (let* ((arglist (help-function-arglist def))
+ (doc (documentation function))
+ (usage (help-split-fundoc doc function)))
+ (with-current-buffer standard-output
+ ;; If definition is a keymap, skip arglist note.
+ (unless (keymapp function)
+ (let* ((use (cond
+ (usage (setq doc (cdr usage)) (car usage))
+ ((listp arglist)
+ (format "%S" (help-make-usage 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 def)
+ (vectorp def))
+ (format "\nMacro: %s" (format-kbd-macro def)))
+ (t "[Missing arglist. Please make a bug report.]")))
+ (high (help-highlight-arguments use doc)))
+ (let ((fill-begin (point)))
+ (insert (car high) "\n")
+ (fill-region fill-begin (point)))
+ (setq doc (cdr high))))
+ (let* ((obsolete (and
+ ;; function might be a lambda construct.
+ (symbolp function)
+ (get function 'byte-obsolete-info)))
+ (use (car obsolete)))
+ (when obsolete
+ (princ "\nThis function is obsolete")
+ (when (nth 2 obsolete)
+ (insert (format " since %s" (nth 2 obsolete))))
+ (insert (cond ((stringp use) (concat ";\n" use))
+ (use (format ";\nuse `%s' instead." use))
+ (t "."))
+ "\n"))
+ (insert "\n"
+ (or doc "Not documented."))))))))
+
+\f
+;; 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
+ (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)
+ val)
+ (setq val (completing-read (if (symbolp v)
+ (format
+ "Describe variable (default %s): " v)
+ "Describe variable: ")
+ obarray
+ '(lambda (vv)
+ (or (boundp vv)
+ (get vv 'variable-documentation)))
+ 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)
+ (interactive-p))
+ (with-help-window (help-buffer)
+ (with-current-buffer buffer
+ (prin1 variable)
+ (setq file-name (find-lisp-object-file-name variable 'defvar))
+
+ (if file-name
+ (progn
+ (princ " is a variable defined in `")
+ (princ (if (eq file-name 'C-source)
+ "C source code"
+ (file-name-nondirectory file-name)))
+ (princ "'.\n")
+ (with-current-buffer standard-output
+ (save-excursion
+ (re-search-backward "`\\([^`']+\\)'" nil t)
+ (help-xref-button 1 'help-variable-def
+ variable file-name)))
+ (if valvoid
+ (princ "It is void as a variable.")
+ (princ "Its ")))
+ (if valvoid
+ (princ " is void as a variable.")
+ (princ "'s "))))
+ (if valvoid
+ nil
+ (with-current-buffer standard-output
+ (setq val-start-pos (point))
+ (princ "value is ")
+ (terpri)
+ (let ((from (point)))
+ (pp val)
+ ;; Hyperlinks in variable's value are quite frequently
+ ;; inappropriate e.g C-h v <RET> features <RET>
+ ;; (help-xref-on-pp from (point))
+ (if (< (point) (+ from 20))
+ (delete-region (1- from) from)))))
+ (terpri)
+
+ (when locus
+ (if (bufferp locus)
+ (princ (format "%socal in buffer %s; "
+ (if (get variable 'permanent-local)
+ "Permanently l" "L")
+ (buffer-name)))
+ (princ (format "It is a frame-local variable; ")))
+ (if (not (default-boundp variable))
+ (princ "globally void")
+ (let ((val (default-value variable)))
+ (with-current-buffer standard-output
+ (princ "global value is ")
+ (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)))
+ (pp val)
+ ;; 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)))
+ (obsolete (get variable 'byte-obsolete-variable))
+ (use (car obsolete))
+ (safe-var (get variable 'safe-local-variable))
+ (doc (or (documentation-property variable 'variable-documentation)
+ (documentation-property alias 'variable-documentation)))
+ (extra-line nil))
+ ;; Add a note for variables that have been make-var-buffer-local.
+ (when (and (local-variable-if-set-p variable)
+ (or (not (local-variable-p variable))
+ (with-temp-buffer
+ (local-variable-if-set-p variable))))
+ (setq extra-line t)
+ (princ " Automatically becomes buffer-local when set in any fashion.\n"))
+
+ ;; Mention if it's an alias
+ (unless (eq alias variable)
+ (setq extra-line t)
+ (princ (format " This variable is an alias for `%s'.\n" alias)))
+
+ (when obsolete
+ (setq extra-line t)
+ (princ " This variable is obsolete")
+ (if (cdr obsolete) (princ (format " since %s" (cdr obsolete))))
+ (princ (cond ((stringp use) (concat ";\n " use))
+ (use (format ";\n use `%s' instead." (car obsolete)))
+ (t ".")))
+ (terpri))
+ (when safe-var
+ (setq extra-line t)
+ (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 byte-compiled expression.\n"
+ (format "`%s'.\n" safe-var))))
+
+ (if extra-line (terpri))
+ (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))))
+
+ (save-excursion
+ (set-buffer standard-output)
+ ;; Return the text we displayed.
+ (buffer-string))))))))
+
+
+;;;###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) (interactive-p))
+ (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 err
+ (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) (interactive-p))
+ (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
+ (insert "Legend of category mnemonics (see the tail for the longer description)\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)
+ (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))))))
+
+(provide 'help-fns)
+
+;; arch-tag: 9e10331c-ae81-4d13-965d-c4819aaab0b3
+;;; help-fns.el ends here