lisp/help-fns.el

   1 ;;; help-fns.el --- Complex help functions -*- lexical-binding: t -*-
   2
   3 ;; Copyright (C) 1985-1986, 1993-1994, 1998-2014 Free Software
   4 ;; Foundation, Inc.
   5
   6 ;; Maintainer: FSF
   7 ;; Keywords: help, internal
   8 ;; Package: emacs
   9
  10 ;; This file is part of GNU Emacs.
  11
  12 ;; GNU Emacs is free software: you can redistribute it and/or modify
  13 ;; it under the terms of the GNU General Public License as published by
  14 ;; the Free Software Foundation, either version 3 of the License, or
  15 ;; (at your option) any later version.
  16
  17 ;; GNU Emacs is distributed in the hope that it will be useful,
  18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ;; GNU General Public License for more details.
  21
  22 ;; You should have received a copy of the GNU General Public License
  23 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  24
  25 ;;; Commentary:
  26
  27 ;; This file contains those help commands which are complicated, and
  28 ;; which may not be used in every session.  For example
  29 ;; `describe-function' will probably be heavily used when doing elisp
  30 ;; programming, but not if just editing C files.  Simpler help commands
  31 ;; are in help.el
  32
  33 ;;; Code:
  34
  35 ;; Functions
  36
  37 ;;;###autoload
  38 (defun describe-function (function)
  39   "Display the full documentation of FUNCTION (a symbol)."
  40   (interactive
  41    (let ((fn (function-called-at-point))
  42          (enable-recursive-minibuffers t)
  43          val)
  44      (setq val (completing-read (if fn
  45                                     (format "Describe function (default %s): " fn)
  46                                   "Describe function: ")
  47                                 obarray 'fboundp t nil nil
  48                                 (and fn (symbol-name fn))))
  49      (list (if (equal val "")
  50                fn (intern val)))))
  51   (if (null function)
  52       (message "You didn't specify a function")
  53     (help-setup-xref (list #'describe-function function)
  54                      (called-interactively-p 'interactive))
  55     (save-excursion
  56       (with-help-window (help-buffer)
  57         (prin1 function)
  58         ;; Use " is " instead of a colon so that
  59         ;; it is easier to get out the function name using forward-sexp.
  60         (princ " is ")
  61         (describe-function-1 function)
  62         (with-current-buffer standard-output
  63           ;; Return the text we displayed.
  64           (buffer-string))))))
  65
  66 (defun help-split-fundoc (docstring def)
  67   "Split a function DOCSTRING into the actual doc and the usage info.
  68 Return (USAGE . DOC) or nil if there's no usage info, where USAGE info
  69 is a string describing the argument list of DEF, such as
  70 \"(apply FUNCTION &rest ARGUMENTS)\".
  71 DEF is the function whose usage we're looking for in DOCSTRING."
  72   ;; Functions can get the calling sequence at the end of the doc string.
  73   ;; In cases where `function' has been fset to a subr we can't search for
  74   ;; function's name in the doc string so we use `fn' as the anonymous
  75   ;; function name instead.
  76   (when (and docstring (string-match "\n\n(fn\\(\\( .*\\)?)\\)\\'" docstring))
  77     (cons (format "(%s%s"
  78                   ;; Replace `fn' with the actual function name.
  79                   (if (symbolp def) def "anonymous")
  80                   (match-string 1 docstring))
  81           (unless (zerop (match-beginning 0))
  82             (substring docstring 0 (match-beginning 0))))))
  83
  84 ;; FIXME: Move to subr.el?
  85 (defun help-add-fundoc-usage (docstring arglist)
  86   "Add the usage info to DOCSTRING.
  87 If DOCSTRING already has a usage info, then just return it unchanged.
  88 The usage info is built from ARGLIST.  DOCSTRING can be nil.
  89 ARGLIST can also be t or a string of the form \"(FUN ARG1 ARG2 ...)\"."
  90   (unless (stringp docstring) (setq docstring ""))
  91   (if (or (string-match "\n\n(fn\\(\\( .*\\)?)\\)\\'" docstring)
  92           (eq arglist t))
  93       docstring
  94     (concat docstring
  95             (if (string-match "\n?\n\\'" docstring)
  96                 (if (< (- (match-end 0) (match-beginning 0)) 2) "\n" "")
  97               "\n\n")
  98             (if (and (stringp arglist)
  99                      (string-match "\\`([^ ]+\\(.*\\))\\'" arglist))
 100                 (concat "(fn" (match-string 1 arglist) ")")
 101               (format "%S" (help-make-usage 'fn arglist))))))
 102
 103 ;; FIXME: Move to subr.el?
 104 (defun help-function-arglist (def &optional preserve-names)
 105   "Return a formal argument list for the function DEF.
 106 IF PRESERVE-NAMES is non-nil, return a formal arglist that uses
 107 the same names as used in the original source code, when possible."
 108   ;; Handle symbols aliased to other symbols.
 109   (if (and (symbolp def) (fboundp def)) (setq def (indirect-function def)))
 110   ;; If definition is a macro, find the function inside it.
 111   (if (eq (car-safe def) 'macro) (setq def (cdr def)))
 112   (cond
 113    ((and (byte-code-function-p def) (listp (aref def 0))) (aref def 0))
 114    ((eq (car-safe def) 'lambda) (nth 1 def))
 115    ((eq (car-safe def) 'closure) (nth 2 def))
 116    ((or (and (byte-code-function-p def) (integerp (aref def 0)))
 117         (subrp def))
 118     (or (when preserve-names
 119           (let* ((doc (condition-case nil (documentation def) (error nil)))
 120                  (docargs (if doc (car (help-split-fundoc doc nil))))
 121                  (arglist (if docargs
 122                               (cdar (read-from-string (downcase docargs)))))
 123                  (valid t))
 124             ;; Check validity.
 125             (dolist (arg arglist)
 126               (unless (and (symbolp arg)
 127                            (let ((name (symbol-name arg)))
 128                              (if (eq (aref name 0) ?&)
 129                                  (memq arg '(&rest &optional))
 130                                (not (string-match "\\." name)))))
 131                 (setq valid nil)))
 132             (when valid arglist)))
 133         (let* ((args-desc (if (not (subrp def))
 134                               (aref def 0)
 135                             (let ((a (subr-arity def)))
 136                               (logior (car a)
 137                                       (if (numberp (cdr a))
 138                                           (lsh (cdr a) 8)
 139                                         (lsh 1 7))))))
 140                (max (lsh args-desc -8))
 141                (min (logand args-desc 127))
 142                (rest (logand args-desc 128))
 143                (arglist ()))
 144           (dotimes (i min)
 145             (push (intern (concat "arg" (number-to-string (1+ i)))) arglist))
 146           (when (> max min)
 147             (push '&optional arglist)
 148             (dotimes (i (- max min))
 149               (push (intern (concat "arg" (number-to-string (+ 1 i min))))
 150                     arglist)))
 151           (unless (zerop rest) (push '&rest arglist) (push 'rest arglist))
 152           (nreverse arglist))))
 153    ((and (autoloadp def) (not (eq (nth 4 def) 'keymap)))
 154     "[Arg list not available until function definition is loaded.]")
 155    (t t)))
 156
 157 ;; FIXME: Move to subr.el?
 158 (defun help-make-usage (function arglist)
 159   (cons (if (symbolp function) function 'anonymous)
 160         (mapcar (lambda (arg)
 161                   (if (not (symbolp arg)) arg
 162                     (let ((name (symbol-name arg)))
 163                       (cond
 164                        ((string-match "\\`&" name) arg)
 165                        ((string-match "\\`_" name)
 166                         (intern (upcase (substring name 1))))
 167                        (t (intern (upcase name)))))))
 168                 arglist)))
 169
 170 ;; Could be this, if we make symbol-file do the work below.
 171 ;; (defun help-C-file-name (subr-or-var kind)
 172 ;;   "Return the name of the C file where SUBR-OR-VAR is defined.
 173 ;; KIND should be `var' for a variable or `subr' for a subroutine."
 174 ;;   (symbol-file (if (symbolp subr-or-var) subr-or-var
 175 ;;               (subr-name subr-or-var))
 176 ;;             (if (eq kind 'var) 'defvar 'defun)))
 177 ;;;###autoload
 178 (defun help-C-file-name (subr-or-var kind)
 179   "Return the name of the C file where SUBR-OR-VAR is defined.
 180 KIND should be `var' for a variable or `subr' for a subroutine."
 181   (let ((docbuf (get-buffer-create " *DOC*"))
 182         (name (if (eq 'var kind)
 183                   (concat "V" (symbol-name subr-or-var))
 184                 (concat "F" (subr-name subr-or-var)))))
 185     (with-current-buffer docbuf
 186       (goto-char (point-min))
 187       (if (eobp)
 188           (insert-file-contents-literally
 189            (expand-file-name internal-doc-file-name doc-directory)))
 190       (let ((file (catch 'loop
 191                     (while t
 192                       (let ((pnt (search-forward (concat "\x1f" name "\n"))))
 193                         (re-search-backward "\x1fS\\(.*\\)")
 194                         (let ((file (match-string 1)))
 195                           (if (member file build-files)
 196                               (throw 'loop file)
 197                             (goto-char pnt))))))))
 198         (if (string-match "^ns.*\\(\\.o\\|obj\\)\\'" file)
 199             (setq file (replace-match ".m" t t file 1))
 200           (if (string-match "\\.\\(o\\|obj\\)\\'" file)
 201               (setq file (replace-match ".c" t t file))))
 202         (if (string-match "\\.\\(c\\|m\\)\\'" file)
 203             (concat "src/" file)
 204           file)))))
 205
 206 (defcustom help-downcase-arguments nil
 207   "If non-nil, argument names in *Help* buffers are downcased."
 208   :type 'boolean
 209   :group 'help
 210   :version "23.2")
 211
 212 (defun help-highlight-arg (arg)
 213   "Highlight ARG as an argument name for a *Help* buffer.
 214 Return ARG in face `help-argument-name'; ARG is also downcased
 215 if the variable `help-downcase-arguments' is non-nil."
 216   (propertize (if help-downcase-arguments (downcase arg) arg)
 217               'face 'help-argument-name))
 218
 219 (defun help-do-arg-highlight (doc args)
 220   (with-syntax-table (make-syntax-table emacs-lisp-mode-syntax-table)
 221     (modify-syntax-entry ?\- "w")
 222     (dolist (arg args)
 223       (setq doc (replace-regexp-in-string
 224                  ;; This is heuristic, but covers all common cases
 225                  ;; except ARG1-ARG2
 226                  (concat "\\<"                   ; beginning of word
 227                          "\\(?:[a-z-]*-\\)?"     ; for xxx-ARG
 228                          "\\("
 229                          (regexp-quote arg)
 230                          "\\)"
 231                          "\\(?:es\\|s\\|th\\)?"  ; for ARGth, ARGs
 232                          "\\(?:-[a-z0-9-]+\\)?"  ; for ARG-xxx, ARG-n
 233                          "\\(?:-[{([<`\"].*?\\)?"; for ARG-{x}, (x), <x>, [x], `x'
 234                          "\\>")                  ; end of word
 235                  (help-highlight-arg arg)
 236                  doc t t 1)))
 237     doc))
 238
 239 (defun help-highlight-arguments (usage doc &rest args)
 240   (when (and usage (string-match "^(" usage))
 241     (with-temp-buffer
 242       (insert usage)
 243       (goto-char (point-min))
 244       (let ((case-fold-search nil)
 245             (next (not (or args (looking-at "\\["))))
 246             (opt nil))
 247         ;; Make a list of all arguments
 248         (skip-chars-forward "^ ")
 249         (while next
 250           (or opt (not (looking-at " &")) (setq opt t))
 251           (if (not (re-search-forward " \\([\\[(]*\\)\\([^] &)\.]+\\)" nil t))
 252               (setq next nil)
 253             (setq args (cons (match-string 2) args))
 254             (when (and opt (string= (match-string 1) "("))
 255               ;; A pesky CL-style optional argument with default value,
 256               ;; so let's skip over it
 257               (search-backward "(")
 258               (goto-char (scan-sexps (point) 1)))))
 259         ;; Highlight arguments in the USAGE string
 260         (setq usage (help-do-arg-highlight (buffer-string) args))
 261         ;; Highlight arguments in the DOC string
 262         (setq doc (and doc (help-do-arg-highlight doc args))))))
 263   ;; Return value is like the one from help-split-fundoc, but highlighted
 264   (cons usage doc))
 265
 266 ;; The following function was compiled from the former functions
 267 ;; `describe-simplify-lib-file-name' and `find-source-lisp-file' with
 268 ;; some excerpts from `describe-function-1' and `describe-variable'.
 269 ;; The only additional twists provided are (1) locate the defining file
 270 ;; for autoloaded functions, and (2) give preference to files in the
 271 ;; "install directory" (directories found via `load-path') rather than
 272 ;; to files in the "compile directory" (directories found by searching
 273 ;; the loaddefs.el file).  We autoload it because it's also used by
 274 ;; `describe-face' (instead of `describe-simplify-lib-file-name').
 275
 276 ;;;###autoload
 277 (defun find-lisp-object-file-name (object type)
 278   "Guess the file that defined the Lisp object OBJECT, of type TYPE.
 279 OBJECT should be a symbol associated with a function, variable, or face;
 280   alternatively, it can be a function definition.
 281 If TYPE is `defvar', search for a variable definition.
 282 If TYPE is `defface', search for a face definition.
 283 If TYPE is the value returned by `symbol-function' for a function symbol,
 284  search for a function definition.
 285
 286 The return value is the absolute name of a readable file where OBJECT is
 287 defined.  If several such files exist, preference is given to a file
 288 found via `load-path'.  The return value can also be `C-source', which
 289 means that OBJECT is a function or variable defined in C.  If no
 290 suitable file is found, return nil."
 291   (let* ((autoloaded (autoloadp type))
 292          (file-name (or (and autoloaded (nth 1 type))
 293                         (symbol-file
 294                          object (if (memq type (list 'defvar 'defface))
 295                                     type
 296                                   'defun)))))
 297     (cond
 298      (autoloaded
 299       ;; An autoloaded function: Locate the file since `symbol-function'
 300       ;; has only returned a bare string here.
 301       (setq file-name
 302             (locate-file file-name load-path '(".el" ".elc") 'readable)))
 303      ((and (stringp file-name)
 304            (string-match "[.]*loaddefs.el\\'" file-name))
 305       ;; An autoloaded variable or face.  Visit loaddefs.el in a buffer
 306       ;; and try to extract the defining file.  The following form is
 307       ;; from `describe-function-1' and `describe-variable'.
 308       (let ((location
 309              (condition-case nil
 310                  (find-function-search-for-symbol object nil file-name)
 311                (error nil))))
 312         (when (cdr location)
 313           (with-current-buffer (car location)
 314             (goto-char (cdr location))
 315             (when (re-search-backward
 316                    "^;;; Generated autoloads from \\(.*\\)" nil t)
 317               (setq file-name
 318                     (locate-file
 319                      (file-name-sans-extension
 320                       (match-string-no-properties 1))
 321                      load-path '(".el" ".elc") 'readable))))))))
 322
 323     (cond
 324      ((and (not file-name) (subrp type))
 325       ;; A built-in function.  The form is from `describe-function-1'.
 326       (if (get-buffer " *DOC*")
 327           (help-C-file-name type 'subr)
 328         'C-source))
 329      ((and (not file-name) (symbolp object)
 330            (integerp (get object 'variable-documentation)))
 331       ;; A variable defined in C.  The form is from `describe-variable'.
 332       (if (get-buffer " *DOC*")
 333           (help-C-file-name object 'var)
 334         'C-source))
 335      ((not (stringp file-name))
 336       ;; If we don't have a file-name string by now, we lost.
 337       nil)
 338      ;; Now, `file-name' should have become an absolute file name.
 339      ;; For files loaded from ~/.foo.elc, try ~/.foo.
 340      ;; This applies to config files like ~/.emacs,
 341      ;; which people sometimes compile.
 342      ((let (fn)
 343         (and (string-match "\\`\\..*\\.elc\\'"
 344                            (file-name-nondirectory file-name))
 345              (string-equal (file-name-directory file-name)
 346                            (file-name-as-directory (expand-file-name "~")))
 347              (file-readable-p (setq fn (file-name-sans-extension file-name)))
 348              fn)))
 349      ;; When the Elisp source file can be found in the install
 350      ;; directory, return the name of that file.
 351      ((let ((lib-name
 352              (if (string-match "[.]elc\\'" file-name)
 353                  (substring-no-properties file-name 0 -1)
 354                file-name)))
 355         (or (and (file-readable-p lib-name) lib-name)
 356             ;; The library might be compressed.
 357             (and (file-readable-p (concat lib-name ".gz")) lib-name))))
 358      ((let* ((lib-name (file-name-nondirectory file-name))
 359              ;; The next form is from `describe-simplify-lib-file-name'.
 360              (file-name
 361               ;; Try converting the absolute file name to a library
 362               ;; name, convert that back to a file name and see if we
 363               ;; get the original one.  If so, they are equivalent.
 364               (if (equal file-name (locate-file lib-name load-path '("")))
 365                   (if (string-match "[.]elc\\'" lib-name)
 366                       (substring-no-properties lib-name 0 -1)
 367                     lib-name)
 368                 file-name))
 369              ;; The next three forms are from `find-source-lisp-file'.
 370              (elc-file (locate-file
 371                         (concat file-name
 372                                 (if (string-match "\\.el\\'" file-name)
 373                                     "c"
 374                                   ".elc"))
 375                         load-path nil 'readable))
 376              (str (when elc-file
 377                     (with-temp-buffer
 378                       (insert-file-contents-literally elc-file nil 0 256)
 379                       (buffer-string))))
 380              (src-file (and str
 381                             (string-match ";;; from file \\(.*\\.el\\)" str)
 382                             (match-string 1 str))))
 383         (and src-file (file-readable-p src-file) src-file))))))
 384
 385 (defun help-fns--key-bindings (function)
 386   (when (commandp function)
 387     (let ((pt2 (with-current-buffer standard-output (point)))
 388           (remapped (command-remapping function)))
 389       (unless (memq remapped '(ignore undefined))
 390         (let ((keys (where-is-internal
 391                      (or remapped function) overriding-local-map nil nil))
 392               non-modified-keys)
 393           (if (and (eq function 'self-insert-command)
 394                    (vectorp (car-safe keys))
 395                    (consp (aref (car keys) 0)))
 396               (princ "It is bound to many ordinary text characters.\n")
 397             ;; Which non-control non-meta keys run this command?
 398             (dolist (key keys)
 399               (if (member (event-modifiers (aref key 0)) '(nil (shift)))
 400                   (push key non-modified-keys)))
 401             (when remapped
 402               (princ "Its keys are remapped to ")
 403               (princ (if (symbolp remapped)
 404                          (concat "`" (symbol-name remapped) "'")
 405                        "an anonymous command"))
 406               (princ ".\n"))
 407
 408             (when keys
 409               (princ (if remapped
 410                          "Without this remapping, it would be bound to "
 411                        "It is bound to "))
 412               ;; If lots of ordinary text characters run this command,
 413               ;; don't mention them one by one.
 414               (if (< (length non-modified-keys) 10)
 415                   (princ (mapconcat 'key-description keys ", "))
 416                 (dolist (key non-modified-keys)
 417                   (setq keys (delq key keys)))
 418                 (if keys
 419                     (progn
 420                       (princ (mapconcat 'key-description keys ", "))
 421                       (princ ", and many ordinary text characters"))
 422                   (princ "many ordinary text characters"))))
 423             (when (or remapped keys non-modified-keys)
 424               (princ ".")
 425               (terpri)))))
 426
 427       (with-current-buffer standard-output
 428         (fill-region-as-paragraph pt2 (point))
 429         (unless (looking-back "\n\n")
 430           (terpri))))))
 431
 432 (defun help-fns--compiler-macro (function)
 433   (let ((handler (function-get function 'compiler-macro)))
 434     (when handler
 435       (insert "\nThis function has a compiler macro")
 436       (if (symbolp handler)
 437           (progn
 438             (insert (format " `%s'" handler))
 439             (save-excursion
 440               (re-search-backward "`\\([^`']+\\)'" nil t)
 441               (help-xref-button 1 'help-function handler)))
 442         ;; FIXME: Obsolete since 24.4.
 443         (let ((lib (get function 'compiler-macro-file)))
 444           (when (stringp lib)
 445             (insert (format " in `%s'" lib))
 446             (save-excursion
 447               (re-search-backward "`\\([^`']+\\)'" nil t)
 448               (help-xref-button 1 'help-function-cmacro function lib)))))
 449       (insert ".\n"))))
 450
 451 (defun help-fns--signature (function doc real-def real-function)
 452   (unless (keymapp function)    ; If definition is a keymap, skip arglist note.
 453     (let* ((advertised (gethash real-def advertised-signature-table t))
 454            (arglist (if (listp advertised)
 455                         advertised (help-function-arglist real-def)))
 456            (usage (help-split-fundoc doc function)))
 457       (if usage (setq doc (cdr usage)))
 458       (let* ((use (cond
 459                    ((and usage (not (listp advertised))) (car usage))
 460                    ((listp arglist)
 461                     (format "%S" (help-make-usage function arglist)))
 462                    ((stringp arglist) arglist)
 463                    ;; Maybe the arglist is in the docstring of a symbol
 464                    ;; this one is aliased to.
 465                    ((let ((fun real-function))
 466                       (while (and (symbolp fun)
 467                                   (setq fun (symbol-function fun))
 468                                   (not (setq usage (help-split-fundoc
 469                                                     (documentation fun)
 470                                                     function)))))
 471                       usage)
 472                     (car usage))
 473                    ((or (stringp real-def)
 474                         (vectorp real-def))
 475                     (format "\nMacro: %s" (format-kbd-macro real-def)))
 476                    (t "[Missing arglist.  Please make a bug report.]")))
 477              (high (help-highlight-arguments use doc)))
 478         (let ((fill-begin (point)))
 479           (insert (car high) "\n")
 480           (fill-region fill-begin (point)))
 481         (cdr high)))))
 482
 483 (defun help-fns--parent-mode (function)
 484   ;; If this is a derived mode, link to the parent.
 485   (let ((parent-mode (and (symbolp function)
 486                           (get function
 487                                'derived-mode-parent))))
 488     (when parent-mode
 489       (insert "\nParent mode: `")
 490       (let ((beg (point)))
 491         (insert (format "%s" parent-mode))
 492         (make-text-button beg (point)
 493                           'type 'help-function
 494                           'help-args (list parent-mode)))
 495       (insert "'.\n"))))
 496
 497 (defun help-fns--obsolete (function)
 498   ;; Ignore lambda constructs, keyboard macros, etc.
 499   (let* ((obsolete (and (symbolp function)
 500                         (get function 'byte-obsolete-info)))
 501          (use (car obsolete)))
 502     (when obsolete
 503       (insert "\nThis "
 504               (if (eq (car-safe (symbol-function function)) 'macro)
 505                   "macro"
 506                 "function")
 507               " is obsolete")
 508       (when (nth 2 obsolete)
 509         (insert (format " since %s" (nth 2 obsolete))))
 510       (insert (cond ((stringp use) (concat ";\n" use))
 511                     (use (format ";\nuse `%s' instead." use))
 512                     (t "."))
 513               "\n"))))
 514
 515 ;; We could use `symbol-file' but this is a wee bit more efficient.
 516 (defun help-fns--autoloaded-p (function file)
 517   "Return non-nil if FUNCTION has previously been autoloaded.
 518 FILE is the file where FUNCTION was probably defined."
 519   (let* ((file (file-name-sans-extension (file-truename file)))
 520          (load-hist load-history)
 521          (target (cons t function))
 522          found)
 523     (while (and load-hist (not found))
 524       (and (caar load-hist)
 525            (equal (file-name-sans-extension (caar load-hist)) file)
 526            (setq found (member target (cdar load-hist))))
 527       (setq load-hist (cdr load-hist)))
 528     found))
 529
 530 ;;;###autoload
 531 (defun describe-function-1 (function)
 532   (let* ((advised (and (symbolp function)
 533                        (featurep 'nadvice)
 534                        (advice--p (advice--symbol-function function))))
 535          ;; If the function is advised, use the symbol that has the
 536          ;; real definition, if that symbol is already set up.
 537          (real-function
 538           (or (and advised
 539                    (let* ((advised-fn (advice--cdr
 540                                        (advice--symbol-function function))))
 541                      (while (advice--p advised-fn)
 542                        (setq advised-fn (advice--cdr advised-fn)))
 543                      advised-fn))
 544               function))
 545          ;; Get the real definition.
 546          (def (if (symbolp real-function)
 547                   (symbol-function real-function)
 548                 real-function))
 549          (aliased (or (symbolp def)
 550                       ;; Advised & aliased function.
 551                       (and advised (symbolp real-function))))
 552          (real-def (cond
 553                     (aliased (let ((f real-function))
 554                                (while (and (fboundp f)
 555                                            (symbolp (symbol-function f)))
 556                                  (setq f (symbol-function f)))
 557                                f))
 558                     ((subrp def) (intern (subr-name def)))
 559                     (t def)))
 560          (file-name (find-lisp-object-file-name function def))
 561          (pt1 (with-current-buffer (help-buffer) (point)))
 562          (beg (if (and (or (byte-code-function-p def)
 563                            (keymapp def)
 564                            (memq (car-safe def) '(macro lambda closure)))
 565                        file-name
 566                        (help-fns--autoloaded-p function file-name))
 567                   (if (commandp def)
 568                       "an interactive autoloaded "
 569                     "an autoloaded ")
 570                 (if (commandp def) "an interactive " "a "))))
 571
 572     ;; Print what kind of function-like object FUNCTION is.
 573     (princ (cond ((or (stringp def) (vectorp def))
 574                   "a keyboard macro")
 575                  ((subrp def)
 576                   (if (eq 'unevalled (cdr (subr-arity def)))
 577                       (concat beg "special form")
 578                     (concat beg "built-in function")))
 579                  ;; Aliases are Lisp functions, so we need to check
 580                  ;; aliases before functions.
 581                  (aliased
 582                   (format "an alias for `%s'" real-def))
 583                  ((or (eq (car-safe def) 'macro)
 584                       ;; For advised macros, def is a lambda
 585                       ;; expression or a byte-code-function-p, so we
 586                       ;; need to check macros before functions.
 587                       (macrop function))
 588                   (concat beg "Lisp macro"))
 589                  ((byte-code-function-p def)
 590                   (concat beg "compiled Lisp function"))
 591                  ((eq (car-safe def) 'lambda)
 592                   (concat beg "Lisp function"))
 593                  ((eq (car-safe def) 'closure)
 594                   (concat beg "Lisp closure"))
 595                  ((autoloadp def)
 596                   (format "%s autoloaded %s"
 597                           (if (commandp def) "an interactive" "an")
 598                           (if (eq (nth 4 def) 'keymap) "keymap"
 599                             (if (nth 4 def) "Lisp macro" "Lisp function"))))
 600                  ((keymapp def)
 601                   (let ((is-full nil)
 602                         (elts (cdr-safe def)))
 603                     (while elts
 604                       (if (char-table-p (car-safe elts))
 605                           (setq is-full t
 606                                 elts nil))
 607                       (setq elts (cdr-safe elts)))
 608                     (concat beg (if is-full "keymap" "sparse keymap"))))
 609                  (t "")))
 610
 611     (if (and aliased (not (fboundp real-def)))
 612         (princ ",\nwhich is not defined.  Please make a bug report.")
 613       (with-current-buffer standard-output
 614         (save-excursion
 615           (save-match-data
 616             (when (re-search-backward "alias for `\\([^`']+\\)'" nil t)
 617               (help-xref-button 1 'help-function real-def)))))
 618
 619       (when file-name
 620         (princ " in `")
 621         ;; We used to add .el to the file name,
 622         ;; but that's completely wrong when the user used load-file.
 623         (princ (if (eq file-name 'C-source)
 624                    "C source code"
 625                  (file-name-nondirectory file-name)))
 626         (princ "'")
 627         ;; Make a hyperlink to the library.
 628         (with-current-buffer standard-output
 629           (save-excursion
 630             (re-search-backward "`\\([^`']+\\)'" nil t)
 631             (help-xref-button 1 'help-function-def function file-name))))
 632       (princ ".")
 633       (with-current-buffer (help-buffer)
 634         (fill-region-as-paragraph (save-excursion (goto-char pt1) (forward-line 0) (point))
 635                                   (point)))
 636       (terpri)(terpri)
 637
 638       (let* ((doc-raw (documentation function t))
 639              ;; If the function is autoloaded, and its docstring has
 640              ;; key substitution constructs, load the library.
 641              (doc (progn
 642                     (and (autoloadp real-def) doc-raw
 643                          help-enable-auto-load
 644                          (string-match "\\([^\\]=\\|[^=]\\|\\`\\)\\\\[[{<]"
 645                                        doc-raw)
 646                          (load (cadr real-def) t))
 647                     (substitute-command-keys doc-raw))))
 648
 649         (help-fns--key-bindings function)
 650         (with-current-buffer standard-output
 651           (setq doc (help-fns--signature function doc real-def real-function))
 652
 653           (help-fns--compiler-macro function)
 654           (help-fns--parent-mode function)
 655           (help-fns--obsolete function)
 656
 657           (insert "\n"
 658                   (or doc "Not documented.")))))))
 659
 660 \f
 661 ;; Variables
 662
 663 ;;;###autoload
 664 (defun variable-at-point (&optional any-symbol)
 665   "Return the bound variable symbol found at or before point.
 666 Return 0 if there is no such symbol.
 667 If ANY-SYMBOL is non-nil, don't insist the symbol be bound."
 668   (with-syntax-table emacs-lisp-mode-syntax-table
 669     (or (condition-case ()
 670             (save-excursion
 671               (skip-chars-forward "'")
 672               (or (not (zerop (skip-syntax-backward "_w")))
 673                   (eq (char-syntax (following-char)) ?w)
 674                   (eq (char-syntax (following-char)) ?_)
 675                   (forward-sexp -1))
 676               (skip-chars-forward "'")
 677               (let ((obj (read (current-buffer))))
 678                 (and (symbolp obj) (boundp obj) obj)))
 679           (error nil))
 680         (let* ((str (find-tag-default))
 681                (sym (if str (intern-soft str))))
 682           (if (and sym (or any-symbol (boundp sym)))
 683               sym
 684             (save-match-data
 685               (when (and str (string-match "\\`\\W*\\(.*?\\)\\W*\\'" str))
 686                 (setq sym (intern-soft (match-string 1 str)))
 687                 (and (or any-symbol (boundp sym)) sym)))))
 688         0)))
 689
 690 (defun describe-variable-custom-version-info (variable)
 691   (let ((custom-version (get variable 'custom-version))
 692         (cpv (get variable 'custom-package-version))
 693         (output nil))
 694     (if custom-version
 695         (setq output
 696               (format "This variable was introduced, or its default value was changed, in\nversion %s of Emacs.\n"
 697                       custom-version))
 698       (when cpv
 699         (let* ((package (car-safe cpv))
 700                (version (if (listp (cdr-safe cpv))
 701                             (car (cdr-safe cpv))
 702                           (cdr-safe cpv)))
 703                (pkg-versions (assq package customize-package-emacs-version-alist))
 704                (emacsv (cdr (assoc version pkg-versions))))
 705           (if (and package version)
 706               (setq output
 707                     (format (concat "This variable was introduced, or its default value was changed, in\nversion %s of the %s package"
 708                                     (if emacsv
 709                                         (format " that is part of Emacs %s" emacsv))
 710                                     ".\n")
 711                             version package))))))
 712     output))
 713
 714 ;;;###autoload
 715 (defun describe-variable (variable &optional buffer frame)
 716   "Display the full documentation of VARIABLE (a symbol).
 717 Returns the documentation as a string, also.
 718 If VARIABLE has a buffer-local value in BUFFER or FRAME
 719 \(default to the current buffer and current frame),
 720 it is displayed along with the global value."
 721   (interactive
 722    (let ((v (variable-at-point))
 723          (enable-recursive-minibuffers t)
 724          val)
 725      (setq val (completing-read (if (symbolp v)
 726                                     (format
 727                                      "Describe variable (default %s): " v)
 728                                   "Describe variable: ")
 729                                 obarray
 730                                 (lambda (vv)
 731                                   (or (get vv 'variable-documentation)
 732                                       (and (boundp vv) (not (keywordp vv)))))
 733                                 t nil nil
 734                                 (if (symbolp v) (symbol-name v))))
 735      (list (if (equal val "")
 736                v (intern val)))))
 737   (let (file-name)
 738     (unless (buffer-live-p buffer) (setq buffer (current-buffer)))
 739     (unless (frame-live-p frame) (setq frame (selected-frame)))
 740     (if (not (symbolp variable))
 741         (message "You did not specify a variable")
 742       (save-excursion
 743         (let ((valvoid (not (with-current-buffer buffer (boundp variable))))
 744               (permanent-local (get variable 'permanent-local))
 745               val val-start-pos locus)
 746           ;; Extract the value before setting up the output buffer,
 747           ;; in case `buffer' *is* the output buffer.
 748           (unless valvoid
 749             (with-selected-frame frame
 750               (with-current-buffer buffer
 751                 (setq val (symbol-value variable)
 752                       locus (variable-binding-locus variable)))))
 753           (help-setup-xref (list #'describe-variable variable buffer)
 754                            (called-interactively-p 'interactive))
 755           (with-help-window (help-buffer)
 756             (with-current-buffer buffer
 757               (prin1 variable)
 758               (setq file-name (find-lisp-object-file-name variable 'defvar))
 759
 760               (if file-name
 761                   (progn
 762                     (princ " is a variable defined in `")
 763                     (princ (if (eq file-name 'C-source)
 764                                "C source code"
 765                              (file-name-nondirectory file-name)))
 766                     (princ "'.\n")
 767                     (with-current-buffer standard-output
 768                       (save-excursion
 769                         (re-search-backward "`\\([^`']+\\)'" nil t)
 770                         (help-xref-button 1 'help-variable-def
 771                                           variable file-name)))
 772                     (if valvoid
 773                         (princ "It is void as a variable.")
 774                       (princ "Its ")))
 775                 (if valvoid
 776                     (princ " is void as a variable.")
 777                   (princ "'s "))))
 778             (unless valvoid
 779               (with-current-buffer standard-output
 780                 (setq val-start-pos (point))
 781                 (princ "value is ")
 782                 (let ((from (point))
 783                       (line-beg (line-beginning-position))
 784                       (print-rep
 785                        (let ((print-quoted t))
 786                          (prin1-to-string val))))
 787                   (if (< (+ (length print-rep) (point) (- line-beg)) 68)
 788                       (insert print-rep)
 789                     (terpri)
 790                     (pp val)
 791                     (if (< (point) (+ 68 (line-beginning-position 0)))
 792                         (delete-region from (1+ from))
 793                       (delete-region (1- from) from)))
 794                   (let* ((sv (get variable 'standard-value))
 795                          (origval (and (consp sv)
 796                                        (condition-case nil
 797                                            (eval (car sv))
 798                                          (error :help-eval-error)))))
 799                     (when (and (consp sv)
 800                                (not (equal origval val))
 801                                (not (equal origval :help-eval-error)))
 802                       (princ "\nOriginal value was \n")
 803                       (setq from (point))
 804                       (pp origval)
 805                       (if (< (point) (+ from 20))
 806                           (delete-region (1- from) from)))))))
 807             (terpri)
 808             (when locus
 809               (cond
 810                ((bufferp locus)
 811                 (princ (format "Local in buffer %s; "
 812                                (buffer-name buffer))))
 813                ((framep locus)
 814                 (princ (format "It is a frame-local variable; ")))
 815                ((terminal-live-p locus)
 816                 (princ (format "It is a terminal-local variable; ")))
 817                (t
 818                 (princ (format "It is local to %S" locus))))
 819               (if (not (default-boundp variable))
 820                   (princ "globally void")
 821                 (let ((global-val (default-value variable)))
 822                   (with-current-buffer standard-output
 823                     (princ "global value is ")
 824                     (if (eq val global-val)
 825                         (princ "the same.")
 826                       (terpri)
 827                       ;; Fixme: pp can take an age if you happen to
 828                       ;; ask for a very large expression.  We should
 829                       ;; probably print it raw once and check it's a
 830                       ;; sensible size before prettyprinting.  -- fx
 831                       (let ((from (point)))
 832                         (pp global-val)
 833                         ;; See previous comment for this function.
 834                         ;; (help-xref-on-pp from (point))
 835                         (if (< (point) (+ from 20))
 836                             (delete-region (1- from) from)))))))
 837               (terpri))
 838
 839             ;; If the value is large, move it to the end.
 840             (with-current-buffer standard-output
 841               (when (> (count-lines (point-min) (point-max)) 10)
 842                 ;; Note that setting the syntax table like below
 843                 ;; makes forward-sexp move over a `'s' at the end
 844                 ;; of a symbol.
 845                 (set-syntax-table emacs-lisp-mode-syntax-table)
 846                 (goto-char val-start-pos)
 847                 ;; The line below previously read as
 848                 ;; (delete-region (point) (progn (end-of-line) (point)))
 849                 ;; which suppressed display of the buffer local value for
 850                 ;; large values.
 851                 (when (looking-at "value is") (replace-match ""))
 852                 (save-excursion
 853                   (insert "\n\nValue:")
 854                   (set (make-local-variable 'help-button-cache)
 855                        (point-marker)))
 856                 (insert "value is shown ")
 857                 (insert-button "below"
 858                                'action help-button-cache
 859                                'follow-link t
 860                                'help-echo "mouse-2, RET: show value")
 861                 (insert ".\n")))
 862             (terpri)
 863
 864             (let* ((alias (condition-case nil
 865                               (indirect-variable variable)
 866                             (error variable)))
 867                    (obsolete (get variable 'byte-obsolete-variable))
 868                    (use (car obsolete))
 869                    (safe-var (get variable 'safe-local-variable))
 870                    (doc (or (documentation-property
 871                              variable 'variable-documentation)
 872                             (documentation-property
 873                              alias 'variable-documentation)))
 874                    (extra-line nil))
 875
 876               ;; Mention if it's a local variable.
 877               (cond
 878                ((and (local-variable-if-set-p variable)
 879                      (or (not (local-variable-p variable))
 880                          (with-temp-buffer
 881                            (local-variable-if-set-p variable))))
 882                 (setq extra-line t)
 883                 (princ "  Automatically becomes ")
 884                 (if permanent-local
 885                     (princ "permanently "))
 886                 (princ "buffer-local when set.\n"))
 887                ((not permanent-local))
 888                ((bufferp locus)
 889                 (setq extra-line t)
 890                 (princ "  This variable's buffer-local value is permanent.\n"))
 891                (t
 892                 (setq extra-line t)
 893                 (princ "  This variable's value is permanent \
 894 if it is given a local binding.\n")))
 895
 896               ;; Mention if it's an alias.
 897               (unless (eq alias variable)
 898                 (setq extra-line t)
 899                 (princ (format "  This variable is an alias for `%s'.\n" alias)))
 900
 901               (when obsolete
 902                 (setq extra-line t)
 903                 (princ "  This variable is obsolete")
 904                 (if (nth 2 obsolete)
 905                     (princ (format " since %s" (nth 2 obsolete))))
 906                 (princ (cond ((stringp use) (concat ";\n  " use))
 907                              (use (format ";\n  use `%s' instead." (car obsolete)))
 908                              (t ".")))
 909                 (terpri))
 910
 911               (when (member (cons variable val) file-local-variables-alist)
 912                 (setq extra-line t)
 913                 (if (member (cons variable val) dir-local-variables-alist)
 914                     (let ((file (and (buffer-file-name)
 915                                       (not (file-remote-p (buffer-file-name)))
 916                                       (dir-locals-find-file
 917                                        (buffer-file-name))))
 918                           (dir-file t))
 919                       (princ "  This variable's value is directory-local")
 920                       (if (null file)
 921                           (princ ".\n")
 922                         (princ ", set ")
 923                         (if (consp file) ; result from cache
 924                             ;; If the cache element has an mtime, we
 925                             ;; assume it came from a file.
 926                             (if (nth 2 file)
 927                                 (setq file (expand-file-name
 928                                             dir-locals-file (car file)))
 929                               ;; Otherwise, assume it was set directly.
 930                               (setq dir-file nil)))
 931                         (princ (if dir-file
 932                                    "by the file\n  `"
 933                                  "for the directory\n  `"))
 934                         (with-current-buffer standard-output
 935                           (insert-text-button
 936                            file 'type 'help-dir-local-var-def
 937                            'help-args (list variable file)))
 938                         (princ "'.\n")))
 939                   (princ "  This variable's value is file-local.\n")))
 940
 941               (when (memq variable ignored-local-variables)
 942                 (setq extra-line t)
 943                 (princ "  This variable is ignored as a file-local \
 944 variable.\n"))
 945
 946               ;; Can be both risky and safe, eg auto-fill-function.
 947               (when (risky-local-variable-p variable)
 948                 (setq extra-line t)
 949                 (princ "  This variable may be risky if used as a \
 950 file-local variable.\n")
 951                 (when (assq variable safe-local-variable-values)
 952                   (princ "  However, you have added it to \
 953 `safe-local-variable-values'.\n")))
 954
 955               (when safe-var
 956                 (setq extra-line t)
 957                 (princ "  This variable is safe as a file local variable ")
 958                 (princ "if its value\n  satisfies the predicate ")
 959                 (princ (if (byte-code-function-p safe-var)
 960                            "which is a byte-compiled expression.\n"
 961                          (format "`%s'.\n" safe-var))))
 962
 963               (if extra-line (terpri))
 964               (princ "Documentation:\n")
 965               (with-current-buffer standard-output
 966                 (insert (or doc "Not documented as a variable."))))
 967
 968             ;; Make a link to customize if this variable can be customized.
 969             (when (custom-variable-p variable)
 970               (let ((customize-label "customize"))
 971                 (terpri)
 972                 (terpri)
 973                 (princ (concat "You can " customize-label " this variable."))
 974                 (with-current-buffer standard-output
 975                   (save-excursion
 976                     (re-search-backward
 977                      (concat "\\(" customize-label "\\)") nil t)
 978                     (help-xref-button 1 'help-customize-variable variable))))
 979               ;; Note variable's version or package version
 980               (let ((output (describe-variable-custom-version-info variable)))
 981                 (when output
 982                   (terpri)
 983                   (terpri)
 984                   (princ output))))
 985
 986             (with-current-buffer standard-output
 987               ;; Return the text we displayed.
 988               (buffer-string))))))))
 989
 990
 991 ;;;###autoload
 992 (defun describe-syntax (&optional buffer)
 993   "Describe the syntax specifications in the syntax table of BUFFER.
 994 The descriptions are inserted in a help buffer, which is then displayed.
 995 BUFFER defaults to the current buffer."
 996   (interactive)
 997   (setq buffer (or buffer (current-buffer)))
 998   (help-setup-xref (list #'describe-syntax buffer)
 999                    (called-interactively-p 'interactive))
1000   (with-help-window (help-buffer)
1001     (let ((table (with-current-buffer buffer (syntax-table))))
1002       (with-current-buffer standard-output
1003         (describe-vector table 'internal-describe-syntax-value)
1004         (while (setq table (char-table-parent table))
1005           (insert "\nThe parent syntax table is:")
1006           (describe-vector table 'internal-describe-syntax-value))))))
1007
1008 (defun help-describe-category-set (value)
1009   (insert (cond
1010            ((null value) "default")
1011            ((char-table-p value) "deeper char-table ...")
1012            (t (condition-case nil
1013                   (category-set-mnemonics value)
1014                 (error "invalid"))))))
1015
1016 ;;;###autoload
1017 (defun describe-categories (&optional buffer)
1018   "Describe the category specifications in the current category table.
1019 The descriptions are inserted in a buffer, which is then displayed.
1020 If BUFFER is non-nil, then describe BUFFER's category table instead.
1021 BUFFER should be a buffer or a buffer name."
1022   (interactive)
1023   (setq buffer (or buffer (current-buffer)))
1024   (help-setup-xref (list #'describe-categories buffer)
1025                    (called-interactively-p 'interactive))
1026   (with-help-window (help-buffer)
1027     (let* ((table (with-current-buffer buffer (category-table)))
1028            (docs (char-table-extra-slot table 0)))
1029       (if (or (not (vectorp docs)) (/= (length docs) 95))
1030           (error "Invalid first extra slot in this category table\n"))
1031       (with-current-buffer standard-output
1032         (insert "Legend of category mnemonics (see the tail for the longer description)\n")
1033         (let ((pos (point)) (items 0) lines n)
1034           (dotimes (i 95)
1035             (if (aref docs i) (setq items (1+ items))))
1036           (setq lines (1+ (/ (1- items) 4)))
1037           (setq n 0)
1038           (dotimes (i 95)
1039             (let ((elt (aref docs i)))
1040               (when elt
1041                 (string-match ".*" elt)
1042                 (setq elt (match-string 0 elt))
1043                 (if (>= (length elt) 17)
1044                     (setq elt (concat (substring elt 0 14) "...")))
1045                 (if (< (point) (point-max))
1046                     (move-to-column (* 20 (/ n lines)) t))
1047                 (insert (+ i ?\s) ?: elt)
1048                 (if (< (point) (point-max))
1049                     (forward-line 1)
1050                   (insert "\n"))
1051                 (setq n (1+ n))
1052                 (if (= (% n lines) 0)
1053                     (goto-char pos))))))
1054         (goto-char (point-max))
1055         (insert "\n"
1056                 "character(s)\tcategory mnemonics\n"
1057                 "------------\t------------------")
1058         (describe-vector table 'help-describe-category-set)
1059         (insert "Legend of category mnemonics:\n")
1060         (dotimes (i 95)
1061           (let ((elt (aref docs i)))
1062             (when elt
1063               (if (string-match "\n" elt)
1064                   (setq elt (substring elt (match-end 0))))
1065               (insert (+ i ?\s) ": " elt "\n"))))
1066         (while (setq table (char-table-parent table))
1067           (insert "\nThe parent category table is:")
1068           (describe-vector table 'help-describe-category-set))))))
1069
1070 \f
1071 ;;; Replacements for old lib-src/ programs.  Don't seem especially useful.
1072
1073 ;; Replaces lib-src/digest-doc.c.
1074 ;;;###autoload
1075 (defun doc-file-to-man (file)
1076   "Produce an nroff buffer containing the doc-strings from the DOC file."
1077   (interactive (list (read-file-name "Name of DOC file: " doc-directory
1078                                      internal-doc-file-name t)))
1079   (or (file-readable-p file)
1080       (error "Cannot read file `%s'" file))
1081   (pop-to-buffer (generate-new-buffer "*man-doc*"))
1082   (setq buffer-undo-list t)
1083   (insert ".TH \"Command Summary for GNU Emacs\"\n"
1084           ".AU Richard M. Stallman\n")
1085   (insert-file-contents file)
1086   (let (notfirst)
1087     (while (search-forward "\x1f" nil 'move)
1088       (if (looking-at "S")
1089           (delete-region (1- (point)) (line-end-position))
1090         (delete-char -1)
1091         (if notfirst
1092             (insert "\n.DE\n")
1093           (setq notfirst t))
1094         (insert "\n.SH ")
1095         (insert (if (looking-at "F") "Function " "Variable "))
1096         (delete-char 1)
1097         (forward-line 1)
1098         (insert ".DS L\n"))))
1099   (insert "\n.DE\n")
1100   (setq buffer-undo-list nil)
1101   (nroff-mode))
1102
1103 ;; Replaces lib-src/sorted-doc.c.
1104 ;;;###autoload
1105 (defun doc-file-to-info (file)
1106   "Produce a texinfo buffer with sorted doc-strings from the DOC file."
1107   (interactive (list (read-file-name "Name of DOC file: " doc-directory
1108                                      internal-doc-file-name t)))
1109   (or (file-readable-p file)
1110       (error "Cannot read file `%s'" file))
1111   (let ((i 0) type name doc alist)
1112     (with-temp-buffer
1113       (insert-file-contents file)
1114       ;; The characters "@{}" need special treatment.
1115       (while (re-search-forward "[@{}]" nil t)
1116         (backward-char)
1117         (insert "@")
1118         (forward-char 1))
1119       (goto-char (point-min))
1120       (while (search-forward "\x1f" nil t)
1121         (unless (looking-at "S")
1122           (setq type (char-after)
1123                 name (buffer-substring (1+ (point)) (line-end-position))
1124                 doc (buffer-substring (line-beginning-position 2)
1125                                       (if (search-forward  "\x1f" nil 'move)
1126                                           (1- (point))
1127                                         (point)))
1128                 alist (cons (list name type doc) alist))
1129           (backward-char 1))))
1130     (pop-to-buffer (generate-new-buffer "*info-doc*"))
1131     (setq buffer-undo-list t)
1132     ;; Write the output header.
1133     (insert "\\input texinfo  @c -*-texinfo-*-\n"
1134             "@setfilename emacsdoc.info\n"
1135             "@settitle Command Summary for GNU Emacs\n"
1136             "@finalout\n"
1137             "\n@node Top\n"
1138             "@unnumbered Command Summary for GNU Emacs\n\n"
1139             "@table @asis\n\n"
1140             "@iftex\n"
1141             "@global@let@ITEM@item\n"
1142             "@def@item{@filbreak@vskip5pt@ITEM}\n"
1143             "@font@tensy cmsy10 scaled @magstephalf\n"
1144             "@font@teni cmmi10 scaled @magstephalf\n"
1145             "@def\\{{@tensy@char110}}\n" ; this backslash goes with cmr10
1146             "@def|{{@tensy@char106}}\n"
1147             "@def@{{{@tensy@char102}}\n"
1148             "@def@}{{@tensy@char103}}\n"
1149             "@def<{{@teni@char62}}\n"
1150             "@def>{{@teni@char60}}\n"
1151             "@chardef@@64\n"
1152             "@catcode43=12\n"
1153             "@tableindent-0.2in\n"
1154             "@end iftex\n")
1155     ;; Sort the array by name; within each name, by type (functions first).
1156     (setq alist (sort alist (lambda (e1 e2)
1157                               (if (string-equal (car e1) (car e2))
1158                                   (<= (cadr e1) (cadr e2))
1159                                 (string-lessp (car e1) (car e2))))))
1160     ;; Print each function.
1161     (dolist (e alist)
1162       (insert "\n@item "
1163               (if (char-equal (cadr e) ?\F) "Function" "Variable")
1164               " @code{" (car e) "}\n@display\n"
1165               (nth 2 e)
1166               "\n@end display\n")
1167       ;; Try to avoid a save size overflow in the TeX output routine.
1168       (if (zerop (setq i (% (1+ i) 100)))
1169           (insert "\n@end table\n@table @asis\n")))
1170     (insert "@end table\n"
1171             "@bye\n")
1172     (setq buffer-undo-list nil)
1173     (texinfo-mode)))
1174
1175 (provide 'help-fns)
1176
1177 ;;; help-fns.el ends here