mirror/emacs
1
0
Fork 0
mirror of https://git.savannah.gnu.org/git/emacs.git synced 2024-12-29 11:02:01 +00:00
Code Issues Releases Activity
4043c1949e
emacs/lisp/help-fns.el
Martin Rudalics e8e8dbf923 (describe-function-1, describe-variable): Print 
relative file name in help buffer.
2008-09-24 16:13:35 +00:00

802 lines
30 KiB
EmacsLisp
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

;;; 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 "^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))))
(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))
(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."))))))))
;; 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))))
(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
Reference in New Issue View Git Blame Copy Permalink