mirror of
https://git.savannah.gnu.org/git/emacs.git
synced 2024-12-03 08:30:09 +00:00
2e6750c8f8
* help-fns.el (variable-at-point): Use emacs-lisp-mode-syntax-table even when calling find-tag-default.
759 lines
29 KiB
EmacsLisp
759 lines
29 KiB
EmacsLisp
;;; 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 " " name "\n"))))
|
||
(re-search-backward " S\\(.*\\)")
|
||
(let ((file (match-string 1)))
|
||
(if (member file build-files)
|
||
(throw 'loop file)
|
||
(goto-char pnt))))))))
|
||
(if (string-match "\\.\\(o\\|obj\\)\\'" file)
|
||
(setq file (replace-match ".c" t t file)))
|
||
(if (string-match "\\.c\\'" 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))
|
||
|
||
;;;###autoload
|
||
(defun describe-simplify-lib-file-name (file)
|
||
"Simplify a library name FILE to a relative name, and make it a source file."
|
||
(if file
|
||
;; Try converting the absolute file name to a library name.
|
||
(let ((libname (file-name-nondirectory file)))
|
||
;; Now convert that back to a file name and see if we get
|
||
;; the original one. If so, they are equivalent.
|
||
(if (equal file (locate-file libname load-path '("")))
|
||
(if (string-match "[.]elc\\'" libname)
|
||
(substring libname 0 -1)
|
||
libname)
|
||
file))))
|
||
|
||
(defun find-source-lisp-file (file-name)
|
||
(let* ((elc-file (locate-file (concat file-name
|
||
(if (string-match "\\.el" file-name)
|
||
"c"
|
||
".elc"))
|
||
load-path))
|
||
(str (if (and elc-file (file-readable-p 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))))
|
||
(if (and src-file (file-readable-p src-file))
|
||
src-file
|
||
file-name)))
|
||
|
||
(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
|
||
(cdr (assq 'origname advised))
|
||
(fboundp (cdr (assq 'origname advised)))
|
||
(cdr (assq 'origname advised)))
|
||
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))))
|
||
(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 (symbolp (symbol-function def))
|
||
(setq def (symbol-function def)))
|
||
(format "an alias for `%s'" def))
|
||
((eq (car-safe def) 'lambda)
|
||
(concat beg "Lisp function"))
|
||
((eq (car-safe def) 'macro)
|
||
"a Lisp macro")
|
||
((eq (car-safe def) 'autoload)
|
||
(setq file-name (nth 1 def))
|
||
(format "%s autoloaded %s"
|
||
(if (commandp def) "an interactive" "an")
|
||
(if (eq (nth 4 def) 'keymap) "keymap"
|
||
(if (nth 4 def) "Lisp macro" "Lisp function"))
|
||
))
|
||
((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)
|
||
(with-current-buffer standard-output
|
||
(save-excursion
|
||
(save-match-data
|
||
(if (re-search-backward "alias for `\\([^`']+\\)'" nil t)
|
||
(help-xref-button 1 'help-function def)))))
|
||
(or file-name
|
||
(setq file-name (symbol-file function 'defun)))
|
||
(setq file-name (describe-simplify-lib-file-name file-name))
|
||
(when (equal file-name "loaddefs.el")
|
||
;; Find the real def site of the preloaded function.
|
||
;; This is necessary only for defaliases.
|
||
(let ((location
|
||
(condition-case nil
|
||
(find-function-search-for-symbol function nil "loaddefs.el")
|
||
(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 (match-string 1)))))))
|
||
(when (and (null file-name) (subrp def))
|
||
;; Find the C source file name.
|
||
(setq file-name (if (get-buffer " *DOC*")
|
||
(help-C-file-name def 'subr)
|
||
'C-source)))
|
||
(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))
|
||
(princ "'")
|
||
;; See if lisp files are present where they where installed from.
|
||
(if (not (eq file-name 'C-source))
|
||
(setq file-name (find-source-lisp-file file-name)))
|
||
|
||
;; 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))))
|
||
(if (and (eq function 'self-insert-command)
|
||
(eq (key-binding "a") 'self-insert-command)
|
||
(eq (key-binding "b") 'self-insert-command)
|
||
(eq (key-binding "c") 'self-insert-command))
|
||
(princ "It is bound to many ordinary text characters.\n")
|
||
(let* ((remapped (command-remapping function))
|
||
(keys (where-is-internal
|
||
(or remapped function) overriding-local-map nil nil))
|
||
non-modified-keys)
|
||
;; 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)))
|
||
(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.")))))))
|
||
|
||
|
||
;; 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)))))
|
||
(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)
|
||
;; Make a hyperlink to the library if appropriate. (Don't
|
||
;; change the format of the buffer's initial line in case
|
||
;; anything expects the current format.)
|
||
(let ((file-name (symbol-file variable 'defvar)))
|
||
(setq file-name (describe-simplify-lib-file-name file-name))
|
||
(when (equal file-name "loaddefs.el")
|
||
;; Find the real def site of the preloaded variable.
|
||
(let ((location
|
||
(condition-case nil
|
||
(find-variable-noselect variable file-name)
|
||
(error nil))))
|
||
(when location
|
||
(with-current-buffer (car location)
|
||
(when (cdr location)
|
||
(goto-char (cdr location)))
|
||
(when (re-search-backward
|
||
"^;;; Generated autoloads from \\(.*\\)" nil t)
|
||
(setq file-name (match-string 1)))))))
|
||
(when (and (null file-name)
|
||
(integerp (get variable 'variable-documentation)))
|
||
;; It's a variable not defined in Elisp but in C.
|
||
(setq file-name
|
||
(if (get-buffer " *DOC*")
|
||
(help-C-file-name variable 'var)
|
||
'C-source)))
|
||
(if file-name
|
||
(progn
|
||
(princ " is a variable defined in `")
|
||
(princ (if (eq file-name 'C-source) "C source code" 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))))
|
||
(with-current-buffer standard-output
|
||
(describe-vector table 'help-describe-category-set)
|
||
(let ((docs (char-table-extra-slot table 0)))
|
||
(if (or (not (vectorp docs)) (/= (length docs) 95))
|
||
(insert "Invalid first extra slot in this char table\n")
|
||
(insert "Meanings of mnemonic characters are:\n")
|
||
(dotimes (i 95)
|
||
(let ((elt (aref docs i)))
|
||
(when elt
|
||
(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
|