lisp/help-fns.el

   1 ;;; help-fns.el --- Complex help functions -*- lexical-binding: t -*-
   2
   3 ;; Copyright (C) 1985-1986, 1993-1994, 1998-2015 Free Software
   4 ;; Foundation, Inc.
   5
   6 ;; Maintainer: emacs-devel@gnu.org
   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 (defvar help-fns-describe-function-functions nil
  36   "List of functions to run in help buffer in `describe-function'.
  37 Those functions will be run after the header line and argument
  38 list was inserted, and before the documentation will be inserted.
  39 The functions will receive the function name as argument.")
  40
  41 ;; Functions
  42
  43 ;;;###autoload
  44 (defun describe-function (function)
  45   "Display the full documentation of FUNCTION (a symbol)."
  46   (interactive
  47    (let ((fn (function-called-at-point))
  48          (enable-recursive-minibuffers t)
  49          val)
  50      (setq val (completing-read (if fn
  51                                     (format "Describe function (default %s): " fn)
  52                                   "Describe function: ")
  53                                 obarray 'fboundp t nil nil
  54                                 (and fn (symbol-name fn))))
  55      (list (if (equal val "")
  56                fn (intern val)))))
  57   (or (and function (symbolp function))
  58       (user-error "You didn't specify a function symbol"))
  59   (or (fboundp function)
  60       (user-error "Symbol's function definition is void: %s" function))
  61   (help-setup-xref (list #'describe-function function)
  62                    (called-interactively-p 'interactive))
  63   (save-excursion
  64     (with-help-window (help-buffer)
  65       (prin1 function)
  66       ;; Use " is " instead of a colon so that
  67       ;; it is easier to get out the function name using forward-sexp.
  68       (princ " is ")
  69       (describe-function-1 function)
  70       (with-current-buffer standard-output
  71         ;; Return the text we displayed.
  72         (buffer-string)))))
  73
  74
  75 ;; Could be this, if we make symbol-file do the work below.
  76 ;; (defun help-C-file-name (subr-or-var kind)
  77 ;;   "Return the name of the C file where SUBR-OR-VAR is defined.
  78 ;; KIND should be `var' for a variable or `subr' for a subroutine."
  79 ;;   (symbol-file (if (symbolp subr-or-var) subr-or-var
  80 ;;               (subr-name subr-or-var))
  81 ;;             (if (eq kind 'var) 'defvar 'defun)))
  82 ;;;###autoload
  83 (defun help-C-file-name (subr-or-var kind)
  84   "Return the name of the C file where SUBR-OR-VAR is defined.
  85 KIND should be `var' for a variable or `subr' for a subroutine."
  86   (let ((docbuf (get-buffer-create " *DOC*"))
  87         (name (if (eq 'var kind)
  88                   (concat "V" (symbol-name subr-or-var))
  89                 (concat "F" (subr-name (advice--cd*r subr-or-var))))))
  90     (with-current-buffer docbuf
  91       (goto-char (point-min))
  92       (if (eobp)
  93           (insert-file-contents-literally
  94            (expand-file-name internal-doc-file-name doc-directory)))
  95       (let ((file (catch 'loop
  96                     (while t
  97                       (let ((pnt (search-forward (concat "\x1f" name "\n"))))
  98                         (re-search-backward "\x1fS\\(.*\\)")
  99                         (let ((file (match-string 1)))
 100                           (if (member file build-files)
 101                               (throw 'loop file)
 102                             (goto-char pnt))))))))
 103         (if (string-match "^ns.*\\(\\.o\\|obj\\)\\'" file)
 104             (setq file (replace-match ".m" t t file 1))
 105           (if (string-match "\\.\\(o\\|obj\\)\\'" file)
 106               (setq file (replace-match ".c" t t file))))
 107         (if (string-match "\\.\\(c\\|m\\)\\'" file)
 108             (concat "src/" file)
 109           file)))))
 110
 111 (defcustom help-downcase-arguments nil
 112   "If non-nil, argument names in *Help* buffers are downcased."
 113   :type 'boolean
 114   :group 'help
 115   :version "23.2")
 116
 117 (defun help-highlight-arg (arg)
 118   "Highlight ARG as an argument name for a *Help* buffer.
 119 Return ARG in face `help-argument-name'; ARG is also downcased
 120 if the variable `help-downcase-arguments' is non-nil."
 121   (propertize (if help-downcase-arguments (downcase arg) arg)
 122               'face 'help-argument-name))
 123
 124 (defun help-do-arg-highlight (doc args)
 125   (with-syntax-table (make-syntax-table emacs-lisp-mode-syntax-table)
 126     (modify-syntax-entry ?\- "w")
 127     (dolist (arg args)
 128       (setq doc (replace-regexp-in-string
 129                  ;; This is heuristic, but covers all common cases
 130                  ;; except ARG1-ARG2
 131                  (concat "\\<"                   ; beginning of word
 132                          "\\(?:[a-z-]*-\\)?"     ; for xxx-ARG
 133                          "\\("
 134                          (regexp-quote arg)
 135                          "\\)"
 136                          "\\(?:es\\|s\\|th\\)?"  ; for ARGth, ARGs
 137                          "\\(?:-[a-z0-9-]+\\)?"  ; for ARG-xxx, ARG-n
 138                          "\\(?:-[{([<`\"‘].*?\\)?"; for ARG-{x}, (x), <x>, [x], `x', ‘x’
 139                          "\\>")                  ; end of word
 140                  (help-highlight-arg arg)
 141                  doc t t 1)))
 142     doc))
 143
 144 (defun help-highlight-arguments (usage doc &rest args)
 145   (when (and usage (string-match "^(" usage))
 146     (with-temp-buffer
 147       (insert usage)
 148       (goto-char (point-min))
 149       (let ((case-fold-search nil)
 150             (next (not (or args (looking-at "\\["))))
 151             (opt nil))
 152         ;; Make a list of all arguments
 153         (skip-chars-forward "^ ")
 154         (while next
 155           (or opt (not (looking-at " &")) (setq opt t))
 156           (if (not (re-search-forward " \\([\\[(]*\\)\\([^] &)\.]+\\)" nil t))
 157               (setq next nil)
 158             (setq args (cons (match-string 2) args))
 159             (when (and opt (string= (match-string 1) "("))
 160               ;; A pesky CL-style optional argument with default value,
 161               ;; so let's skip over it
 162               (search-backward "(")
 163               (goto-char (scan-sexps (point) 1)))))
 164         ;; Highlight arguments in the USAGE string
 165         (setq usage (help-do-arg-highlight (buffer-string) args))
 166         ;; Highlight arguments in the DOC string
 167         (setq doc (and doc (help-do-arg-highlight doc args))))))
 168   ;; Return value is like the one from help-split-fundoc, but highlighted
 169   (cons usage doc))
 170
 171 ;; The following function was compiled from the former functions
 172 ;; `describe-simplify-lib-file-name' and `find-source-lisp-file' with
 173 ;; some excerpts from `describe-function-1' and `describe-variable'.
 174 ;; The only additional twists provided are (1) locate the defining file
 175 ;; for autoloaded functions, and (2) give preference to files in the
 176 ;; "install directory" (directories found via `load-path') rather than
 177 ;; to files in the "compile directory" (directories found by searching
 178 ;; the loaddefs.el file).  We autoload it because it's also used by
 179 ;; `describe-face' (instead of `describe-simplify-lib-file-name').
 180
 181 ;;;###autoload
 182 (defun find-lisp-object-file-name (object type)
 183   "Guess the file that defined the Lisp object OBJECT, of type TYPE.
 184 OBJECT should be a symbol associated with a function, variable, or face;
 185   alternatively, it can be a function definition.
 186 If TYPE is `defvar', search for a variable definition.
 187 If TYPE is `defface', search for a face definition.
 188 If TYPE is not a symbol, search for a function definition.
 189
 190 The return value is the absolute name of a readable file where OBJECT is
 191 defined.  If several such files exist, preference is given to a file
 192 found via `load-path'.  The return value can also be `C-source', which
 193 means that OBJECT is a function or variable defined in C.  If no
 194 suitable file is found, return nil."
 195   (let* ((autoloaded (autoloadp type))
 196          (file-name (or (and autoloaded (nth 1 type))
 197                         (symbol-file
 198                          ;; FIXME: Why do we have this weird "If TYPE is the
 199                          ;; value returned by `symbol-function' for a function
 200                          ;; symbol" exception?
 201                          object (or (if (symbolp type) type) 'defun)))))
 202     (cond
 203      (autoloaded
 204       ;; An autoloaded function: Locate the file since `symbol-function'
 205       ;; has only returned a bare string here.
 206       (setq file-name
 207             (locate-file file-name load-path '(".el" ".elc") 'readable)))
 208      ((and (stringp file-name)
 209            (string-match "[.]*loaddefs.el\\'" file-name))
 210       ;; An autoloaded variable or face.  Visit loaddefs.el in a buffer
 211       ;; and try to extract the defining file.  The following form is
 212       ;; from `describe-function-1' and `describe-variable'.
 213       (let ((location
 214              (condition-case nil
 215                  (find-function-search-for-symbol object nil file-name)
 216                (error nil))))
 217         (when (cdr location)
 218           (with-current-buffer (car location)
 219             (goto-char (cdr location))
 220             (when (re-search-backward
 221                    "^;;; Generated autoloads from \\(.*\\)" nil t)
 222               (setq file-name
 223                     (locate-file
 224                      (file-name-sans-extension
 225                       (match-string-no-properties 1))
 226                      load-path '(".el" ".elc") 'readable))))))))
 227
 228     (cond
 229      ((and (not file-name) (subrp type))
 230       ;; A built-in function.  The form is from `describe-function-1'.
 231       (if (get-buffer " *DOC*")
 232           (help-C-file-name type 'subr)
 233         'C-source))
 234      ((and (not file-name) (symbolp object)
 235            (integerp (get object 'variable-documentation)))
 236       ;; A variable defined in C.  The form is from `describe-variable'.
 237       (if (get-buffer " *DOC*")
 238           (help-C-file-name object 'var)
 239         'C-source))
 240      ((not (stringp file-name))
 241       ;; If we don't have a file-name string by now, we lost.
 242       nil)
 243      ;; Now, `file-name' should have become an absolute file name.
 244      ;; For files loaded from ~/.foo.elc, try ~/.foo.
 245      ;; This applies to config files like ~/.emacs,
 246      ;; which people sometimes compile.
 247      ((let (fn)
 248         (and (string-match "\\`\\..*\\.elc\\'"
 249                            (file-name-nondirectory file-name))
 250              (string-equal (file-name-directory file-name)
 251                            (file-name-as-directory (expand-file-name "~")))
 252              (file-readable-p (setq fn (file-name-sans-extension file-name)))
 253              fn)))
 254      ;; When the Elisp source file can be found in the install
 255      ;; directory, return the name of that file.
 256      ((let ((lib-name
 257              (if (string-match "[.]elc\\'" file-name)
 258                  (substring-no-properties file-name 0 -1)
 259                file-name)))
 260         (or (and (file-readable-p lib-name) lib-name)
 261             ;; The library might be compressed.
 262             (and (file-readable-p (concat lib-name ".gz")) lib-name))))
 263      ((let* ((lib-name (file-name-nondirectory file-name))
 264              ;; The next form is from `describe-simplify-lib-file-name'.
 265              (file-name
 266               ;; Try converting the absolute file name to a library
 267               ;; name, convert that back to a file name and see if we
 268               ;; get the original one.  If so, they are equivalent.
 269               (if (equal file-name (locate-file lib-name load-path '("")))
 270                   (if (string-match "[.]elc\\'" lib-name)
 271                       (substring-no-properties lib-name 0 -1)
 272                     lib-name)
 273                 file-name))
 274              ;; The next three forms are from `find-source-lisp-file'.
 275              (elc-file (locate-file
 276                         (concat file-name
 277                                 (if (string-match "\\.el\\'" file-name)
 278                                     "c"
 279                                   ".elc"))
 280                         load-path nil 'readable))
 281              (str (when elc-file
 282                     (with-temp-buffer
 283                       (insert-file-contents-literally elc-file nil 0 256)
 284                       (buffer-string))))
 285              (src-file (and str
 286                             (string-match ";;; from file \\(.*\\.el\\)" str)
 287                             (match-string 1 str))))
 288         (and src-file (file-readable-p src-file) src-file))))))
 289
 290 (defun help-fns--key-bindings (function)
 291   (when (commandp function)
 292     (let ((pt2 (with-current-buffer standard-output (point)))
 293           (remapped (command-remapping function)))
 294       (unless (memq remapped '(ignore undefined))
 295         (let ((keys (where-is-internal
 296                      (or remapped function) overriding-local-map nil nil))
 297               non-modified-keys)
 298           (if (and (eq function 'self-insert-command)
 299                    (vectorp (car-safe keys))
 300                    (consp (aref (car keys) 0)))
 301               (princ "It is bound to many ordinary text characters.\n")
 302             ;; Which non-control non-meta keys run this command?
 303             (dolist (key keys)
 304               (if (member (event-modifiers (aref key 0)) '(nil (shift)))
 305                   (push key non-modified-keys)))
 306             (when remapped
 307               (princ "Its keys are remapped to ")
 308               (princ (if (symbolp remapped)
 309                          (concat (substitute-command-keys "‘")
 310                                  (symbol-name remapped)
 311                                  (substitute-command-keys "’"))
 312                        "an anonymous command"))
 313               (princ ".\n"))
 314
 315             (when keys
 316               (princ (if remapped
 317                          "Without this remapping, it would be bound to "
 318                        "It is bound to "))
 319               ;; If lots of ordinary text characters run this command,
 320               ;; don't mention them one by one.
 321               (if (< (length non-modified-keys) 10)
 322                   (princ (mapconcat 'key-description keys ", "))
 323                 (dolist (key non-modified-keys)
 324                   (setq keys (delq key keys)))
 325                 (if keys
 326                     (progn
 327                       (princ (mapconcat 'key-description keys ", "))
 328                       (princ ", and many ordinary text characters"))
 329                   (princ "many ordinary text characters"))))
 330             (when (or remapped keys non-modified-keys)
 331               (princ ".")
 332               (terpri)))))
 333
 334       (with-current-buffer standard-output
 335         (fill-region-as-paragraph pt2 (point))
 336         (unless (looking-back "\n\n" (- (point) 2))
 337           (terpri))))))
 338
 339 (defun help-fns--compiler-macro (function)
 340   (let ((handler (function-get function 'compiler-macro)))
 341     (when handler
 342       (insert "\nThis function has a compiler macro")
 343       (if (symbolp handler)
 344           (progn
 345             (insert (format (substitute-command-keys " ‘%s’") handler))
 346             (save-excursion
 347               (re-search-backward (substitute-command-keys "‘\\([^‘’]+\\)’")
 348                                   nil t)
 349               (help-xref-button 1 'help-function handler)))
 350         ;; FIXME: Obsolete since 24.4.
 351         (let ((lib (get function 'compiler-macro-file)))
 352           (when (stringp lib)
 353             (insert (format (substitute-command-keys " in ‘%s’") lib))
 354             (save-excursion
 355               (re-search-backward (substitute-command-keys "‘\\([^‘’]+\\)’")
 356                                   nil t)
 357               (help-xref-button 1 'help-function-cmacro function lib)))))
 358       (insert ".\n"))))
 359
 360 (defun help-fns--signature (function doc real-def real-function raw)
 361   "Insert usage at point and return docstring.  With highlighting."
 362   (if (keymapp function)
 363       doc                       ; If definition is a keymap, skip arglist note.
 364     (let* ((advertised (gethash real-def advertised-signature-table t))
 365            (arglist (if (listp advertised)
 366                         advertised (help-function-arglist real-def)))
 367            (usage (help-split-fundoc doc function)))
 368       (if usage (setq doc (cdr usage)))
 369       (let* ((use (cond
 370                    ((and usage (not (listp advertised))) (car usage))
 371                    ((listp arglist)
 372                     (help--make-usage-docstring function arglist))
 373                    ((stringp arglist) arglist)
 374                    ;; Maybe the arglist is in the docstring of a symbol
 375                    ;; this one is aliased to.
 376                    ((let ((fun real-function))
 377                       (while (and (symbolp fun)
 378                                   (setq fun (symbol-function fun))
 379                                   (not (setq usage (help-split-fundoc
 380                                                     (documentation fun)
 381                                                     function)))))
 382                       usage)
 383                     (car usage))
 384                    ((or (stringp real-def)
 385                         (vectorp real-def))
 386                     (format "\nMacro: %s"
 387                             (help--docstring-quote
 388                              (format-kbd-macro real-def))))
 389                    (t "[Missing arglist.  Please make a bug report.]")))
 390              ;; Insert "`X", not "(\` X)", when documenting `X.
 391              (use1 (replace-regexp-in-string
 392                     "\\`(\\\\=\\\\\\\\=` \\([^\n ]*\\))\\'"
 393                     "\\\\=`\\1" use t))
 394              (high (if raw
 395                        (cons use1 doc)
 396                      (help-highlight-arguments (substitute-command-keys use1)
 397                                                (substitute-command-keys doc)))))
 398         (let ((fill-begin (point))
 399               (high-usage (car high))
 400               (high-doc (cdr high)))
 401           (insert high-usage "\n")
 402           (fill-region fill-begin (point))
 403           high-doc)))))
 404
 405 (defun help-fns--parent-mode (function)
 406   ;; If this is a derived mode, link to the parent.
 407   (let ((parent-mode (and (symbolp function)
 408                           (get function
 409                                'derived-mode-parent))))
 410     (when parent-mode
 411       (insert (substitute-command-keys "\nParent mode: ‘"))
 412       (let ((beg (point)))
 413         (insert (format "%s" parent-mode))
 414         (make-text-button beg (point)
 415                           'type 'help-function
 416                           'help-args (list parent-mode)))
 417       (insert (substitute-command-keys "’.\n")))))
 418
 419 (defun help-fns--obsolete (function)
 420   ;; Ignore lambda constructs, keyboard macros, etc.
 421   (let* ((obsolete (and (symbolp function)
 422                         (get function 'byte-obsolete-info)))
 423          (use (car obsolete)))
 424     (when obsolete
 425       (insert "\nThis "
 426               (if (eq (car-safe (symbol-function function)) 'macro)
 427                   "macro"
 428                 "function")
 429               " is obsolete")
 430       (when (nth 2 obsolete)
 431         (insert (format " since %s" (nth 2 obsolete))))
 432       (insert (cond ((stringp use) (concat ";\n" use))
 433                     (use (format (substitute-command-keys
 434                                   ";\nuse ‘%s’ instead.")
 435                                  use))
 436                     (t "."))
 437               "\n"))))
 438
 439 ;; We could use `symbol-file' but this is a wee bit more efficient.
 440 (defun help-fns--autoloaded-p (function file)
 441   "Return non-nil if FUNCTION has previously been autoloaded.
 442 FILE is the file where FUNCTION was probably defined."
 443   (let* ((file (file-name-sans-extension (file-truename file)))
 444          (load-hist load-history)
 445          (target (cons t function))
 446          found)
 447     (while (and load-hist (not found))
 448       (and (caar load-hist)
 449            (equal (file-name-sans-extension (caar load-hist)) file)
 450            (setq found (member target (cdar load-hist))))
 451       (setq load-hist (cdr load-hist)))
 452     found))
 453
 454 (defun help-fns--interactive-only (function)
 455   "Insert some help blurb if FUNCTION should only be used interactively."
 456   ;; Ignore lambda constructs, keyboard macros, etc.
 457   (and (symbolp function)
 458        (not (eq (car-safe (symbol-function function)) 'macro))
 459        (let* ((interactive-only
 460                (or (get function 'interactive-only)
 461                    (if (boundp 'byte-compile-interactive-only-functions)
 462                        (memq function
 463                              byte-compile-interactive-only-functions)))))
 464          (when interactive-only
 465            (insert "\nThis function is for interactive use only"
 466                    ;; Cf byte-compile-form.
 467                    (cond ((stringp interactive-only)
 468                           (format ";\nin Lisp code %s" interactive-only))
 469                          ((and (symbolp 'interactive-only)
 470                                (not (eq interactive-only t)))
 471                           (format (substitute-command-keys
 472                                    ";\nin Lisp code use ‘%s’ instead.")
 473                                   interactive-only))
 474                          (t "."))
 475                    "\n")))))
 476
 477 (defun help-fns-short-filename (filename)
 478   (let* ((abbrev (abbreviate-file-name filename))
 479          (short abbrev))
 480     (dolist (dir load-path)
 481       (let ((rel (file-relative-name filename dir)))
 482         (if (< (length rel) (length short))
 483             (setq short rel)))
 484       (let ((rel (file-relative-name abbrev dir)))
 485         (if (< (length rel) (length short))
 486             (setq short rel))))
 487     short))
 488
 489 ;;;###autoload
 490 (defun describe-function-1 (function)
 491   (let* ((advised (and (symbolp function)
 492                        (featurep 'nadvice)
 493                        (advice--p (advice--symbol-function function))))
 494          ;; If the function is advised, use the symbol that has the
 495          ;; real definition, if that symbol is already set up.
 496          (real-function
 497           (or (and advised
 498                    (advice--cd*r (advice--symbol-function function)))
 499               function))
 500          ;; Get the real definition.
 501          (def (if (symbolp real-function)
 502                   (or (symbol-function real-function)
 503                       (signal 'void-function (list real-function)))
 504                 real-function))
 505          (aliased (or (symbolp def)
 506                       ;; Advised & aliased function.
 507                       (and advised (symbolp real-function))))
 508          (real-def (cond
 509                     (aliased (let ((f real-function))
 510                                (while (and (fboundp f)
 511                                            (symbolp (symbol-function f)))
 512                                  (setq f (symbol-function f)))
 513                                f))
 514                     ((subrp def) (intern (subr-name def)))
 515                     (t def)))
 516          (sig-key (if (subrp def)
 517                       (indirect-function real-def)
 518                     real-def))
 519          (file-name (find-lisp-object-file-name function def))
 520          (pt1 (with-current-buffer (help-buffer) (point)))
 521          (beg (if (and (or (byte-code-function-p def)
 522                            (keymapp def)
 523                            (memq (car-safe def) '(macro lambda closure)))
 524                        (stringp file-name)
 525                        (help-fns--autoloaded-p function file-name))
 526                   (if (commandp def)
 527                       "an interactive autoloaded "
 528                     "an autoloaded ")
 529                 (if (commandp def) "an interactive " "a "))))
 530
 531     ;; Print what kind of function-like object FUNCTION is.
 532     (princ (cond ((or (stringp def) (vectorp def))
 533                   "a keyboard macro")
 534                  ((subrp def)
 535                   (if (eq 'unevalled (cdr (subr-arity def)))
 536                       (concat beg "special form")
 537                     (concat beg "built-in function")))
 538                  ;; Aliases are Lisp functions, so we need to check
 539                  ;; aliases before functions.
 540                  (aliased
 541                   (format (substitute-command-keys "an alias for ‘%s’")
 542                           real-def))
 543                  ((autoloadp def)
 544                   (format "%s autoloaded %s"
 545                           (if (commandp def) "an interactive" "an")
 546                           (if (eq (nth 4 def) 'keymap) "keymap"
 547                             (if (nth 4 def) "Lisp macro" "Lisp function"))))
 548                  ((or (eq (car-safe def) 'macro)
 549                       ;; For advised macros, def is a lambda
 550                       ;; expression or a byte-code-function-p, so we
 551                       ;; need to check macros before functions.
 552                       (macrop function))
 553                   (concat beg "Lisp macro"))
 554                  ((byte-code-function-p def)
 555                   (concat beg "compiled Lisp function"))
 556                  ((eq (car-safe def) 'lambda)
 557                   (concat beg "Lisp function"))
 558                  ((eq (car-safe def) 'closure)
 559                   (concat beg "Lisp closure"))
 560                  ((keymapp def)
 561                   (let ((is-full nil)
 562                         (elts (cdr-safe def)))
 563                     (while elts
 564                       (if (char-table-p (car-safe elts))
 565                           (setq is-full t
 566                                 elts nil))
 567                       (setq elts (cdr-safe elts)))
 568                     (concat beg (if is-full "keymap" "sparse keymap"))))
 569                  (t "")))
 570
 571     (if (and aliased (not (fboundp real-def)))
 572         (princ ",\nwhich is not defined.  Please make a bug report.")
 573       (with-current-buffer standard-output
 574         (save-excursion
 575           (save-match-data
 576             (when (re-search-backward (substitute-command-keys
 577                                        "alias for ‘\\([^‘’]+\\)’")
 578                                       nil t)
 579               (help-xref-button 1 'help-function real-def)))))
 580
 581       (when file-name
 582         (princ (substitute-command-keys " in ‘"))
 583         ;; We used to add .el to the file name,
 584         ;; but that's completely wrong when the user used load-file.
 585         (princ (if (eq file-name 'C-source)
 586                    "C source code"
 587                  (help-fns-short-filename file-name)))
 588         (princ (substitute-command-keys "’"))
 589         ;; Make a hyperlink to the library.
 590         (with-current-buffer standard-output
 591           (save-excursion
 592             (re-search-backward (substitute-command-keys "‘\\([^‘’]+\\)’")
 593                                 nil t)
 594             (help-xref-button 1 'help-function-def function file-name))))
 595       (princ ".")
 596       (with-current-buffer (help-buffer)
 597         (fill-region-as-paragraph (save-excursion (goto-char pt1) (forward-line 0) (point))
 598                                   (point)))
 599       (terpri)(terpri)
 600
 601       (let ((doc-raw (documentation function t)))
 602
 603         ;; If the function is autoloaded, and its docstring has
 604         ;; key substitution constructs, load the library.
 605         (and (autoloadp real-def) doc-raw
 606              help-enable-auto-load
 607              (string-match "\\([^\\]=\\|[^=]\\|\\`\\)\\\\[[{<]" doc-raw)
 608              (autoload-do-load real-def))
 609
 610         (help-fns--key-bindings function)
 611         (with-current-buffer standard-output
 612           (let ((doc (help-fns--signature function doc-raw sig-key
 613                                           real-function nil)))
 614             (run-hook-with-args 'help-fns-describe-function-functions function)
 615             (insert "\n"
 616                     (or doc "Not documented."))))))))
 617
 618 ;; Add defaults to `help-fns-describe-function-functions'.
 619 (add-hook 'help-fns-describe-function-functions #'help-fns--obsolete)
 620 (add-hook 'help-fns-describe-function-functions #'help-fns--interactive-only)
 621 (add-hook 'help-fns-describe-function-functions #'help-fns--parent-mode)
 622 (add-hook 'help-fns-describe-function-functions #'help-fns--compiler-macro)
 623
 624 \f
 625 ;; Variables
 626
 627 ;;;###autoload
 628 (defun variable-at-point (&optional any-symbol)
 629   "Return the bound variable symbol found at or before point.
 630 Return 0 if there is no such symbol.
 631 If ANY-SYMBOL is non-nil, don't insist the symbol be bound."
 632   (with-syntax-table emacs-lisp-mode-syntax-table
 633     (or (condition-case ()
 634             (save-excursion
 635               (skip-chars-forward "'")
 636               (or (not (zerop (skip-syntax-backward "_w")))
 637                   (eq (char-syntax (following-char)) ?w)
 638                   (eq (char-syntax (following-char)) ?_)
 639                   (forward-sexp -1))
 640               (skip-chars-forward "'")
 641               (let ((obj (read (current-buffer))))
 642                 (and (symbolp obj) (boundp obj) obj)))
 643           (error nil))
 644         (let* ((str (find-tag-default))
 645                (sym (if str (intern-soft str))))
 646           (if (and sym (or any-symbol (boundp sym)))
 647               sym
 648             (save-match-data
 649               (when (and str (string-match "\\`\\W*\\(.*?\\)\\W*\\'" str))
 650                 (setq sym (intern-soft (match-string 1 str)))
 651                 (and (or any-symbol (boundp sym)) sym)))))
 652         0)))
 653
 654 (defun describe-variable-custom-version-info (variable)
 655   (let ((custom-version (get variable 'custom-version))
 656         (cpv (get variable 'custom-package-version))
 657         (output nil))
 658     (if custom-version
 659         (setq output
 660               (format "This variable was introduced, or its default value was changed, in\nversion %s of Emacs.\n"
 661                       custom-version))
 662       (when cpv
 663         (let* ((package (car-safe cpv))
 664                (version (if (listp (cdr-safe cpv))
 665                             (car (cdr-safe cpv))
 666                           (cdr-safe cpv)))
 667                (pkg-versions (assq package customize-package-emacs-version-alist))
 668                (emacsv (cdr (assoc version pkg-versions))))
 669           (if (and package version)
 670               (setq output
 671                     (format (concat "This variable was introduced, or its default value was changed, in\nversion %s of the %s package"
 672                                     (if emacsv
 673                                         (format " that is part of Emacs %s" emacsv))
 674                                     ".\n")
 675                             version package))))))
 676     output))
 677
 678 ;;;###autoload
 679 (defun describe-variable (variable &optional buffer frame)
 680   "Display the full documentation of VARIABLE (a symbol).
 681 Returns the documentation as a string, also.
 682 If VARIABLE has a buffer-local value in BUFFER or FRAME
 683 \(default to the current buffer and current frame),
 684 it is displayed along with the global value."
 685   (interactive
 686    (let ((v (variable-at-point))
 687          (enable-recursive-minibuffers t)
 688          val)
 689      (setq val (completing-read (if (symbolp v)
 690                                     (format
 691                                      "Describe variable (default %s): " v)
 692                                   "Describe variable: ")
 693                                 obarray
 694                                 (lambda (vv)
 695                                   (or (get vv 'variable-documentation)
 696                                       (and (boundp vv) (not (keywordp vv)))))
 697                                 t nil nil
 698                                 (if (symbolp v) (symbol-name v))))
 699      (list (if (equal val "")
 700                v (intern val)))))
 701   (let (file-name)
 702     (unless (buffer-live-p buffer) (setq buffer (current-buffer)))
 703     (unless (frame-live-p frame) (setq frame (selected-frame)))
 704     (if (not (symbolp variable))
 705         (message "You did not specify a variable")
 706       (save-excursion
 707         (let ((valvoid (not (with-current-buffer buffer (boundp variable))))
 708               (permanent-local (get variable 'permanent-local))
 709               val val-start-pos locus)
 710           ;; Extract the value before setting up the output buffer,
 711           ;; in case `buffer' *is* the output buffer.
 712           (unless valvoid
 713             (with-selected-frame frame
 714               (with-current-buffer buffer
 715                 (setq val (symbol-value variable)
 716                       locus (variable-binding-locus variable)))))
 717           (help-setup-xref (list #'describe-variable variable buffer)
 718                            (called-interactively-p 'interactive))
 719           (with-help-window (help-buffer)
 720             (with-current-buffer buffer
 721               (prin1 variable)
 722               (setq file-name (find-lisp-object-file-name variable 'defvar))
 723
 724               (if file-name
 725                   (progn
 726                     (princ (substitute-command-keys
 727                             " is a variable defined in ‘"))
 728                     (princ (if (eq file-name 'C-source)
 729                                "C source code"
 730                              (file-name-nondirectory file-name)))
 731                     (princ (substitute-command-keys "’.\n"))
 732                     (with-current-buffer standard-output
 733                       (save-excursion
 734                         (re-search-backward (substitute-command-keys
 735                                              "‘\\([^‘’]+\\)’")
 736                                             nil t)
 737                         (help-xref-button 1 'help-variable-def
 738                                           variable file-name)))
 739                     (if valvoid
 740                         (princ "It is void as a variable.")
 741                       (princ "Its ")))
 742                 (if valvoid
 743                     (princ " is void as a variable.")
 744                   (princ "'s "))))
 745             (unless valvoid
 746               (with-current-buffer standard-output
 747                 (setq val-start-pos (point))
 748                 (princ "value is ")
 749                 (let ((from (point))
 750                       (line-beg (line-beginning-position))
 751                       (print-rep
 752                        (let ((print-quoted t))
 753                          (prin1-to-string val))))
 754                   (if (< (+ (length print-rep) (point) (- line-beg)) 68)
 755                       (insert print-rep)
 756                     (terpri)
 757                     (pp val)
 758                     (if (< (point) (+ 68 (line-beginning-position 0)))
 759                         (delete-region from (1+ from))
 760                       (delete-region (1- from) from)))
 761                   (let* ((sv (get variable 'standard-value))
 762                          (origval (and (consp sv)
 763                                        (condition-case nil
 764                                            (eval (car sv))
 765                                          (error :help-eval-error)))))
 766                     (when (and (consp sv)
 767                                (not (equal origval val))
 768                                (not (equal origval :help-eval-error)))
 769                       (princ "\nOriginal value was \n")
 770                       (setq from (point))
 771                       (pp origval)
 772                       (if (< (point) (+ from 20))
 773                           (delete-region (1- from) from)))))))
 774             (terpri)
 775             (when locus
 776               (cond
 777                ((bufferp locus)
 778                 (princ (format "Local in buffer %s; "
 779                                (buffer-name buffer))))
 780                ((framep locus)
 781                 (princ (format "It is a frame-local variable; ")))
 782                ((terminal-live-p locus)
 783                 (princ (format "It is a terminal-local variable; ")))
 784                (t
 785                 (princ (format "It is local to %S" locus))))
 786               (if (not (default-boundp variable))
 787                   (princ "globally void")
 788                 (let ((global-val (default-value variable)))
 789                   (with-current-buffer standard-output
 790                     (princ "global value is ")
 791                     (if (eq val global-val)
 792                         (princ "the same.")
 793                       (terpri)
 794                       ;; Fixme: pp can take an age if you happen to
 795                       ;; ask for a very large expression.  We should
 796                       ;; probably print it raw once and check it's a
 797                       ;; sensible size before prettyprinting.  -- fx
 798                       (let ((from (point)))
 799                         (pp global-val)
 800                         ;; See previous comment for this function.
 801                         ;; (help-xref-on-pp from (point))
 802                         (if (< (point) (+ from 20))
 803                             (delete-region (1- from) from)))))))
 804               (terpri))
 805
 806             ;; If the value is large, move it to the end.
 807             (with-current-buffer standard-output
 808               (when (> (count-lines (point-min) (point-max)) 10)
 809                 ;; Note that setting the syntax table like below
 810                 ;; makes forward-sexp move over a `'s' at the end
 811                 ;; of a symbol.
 812                 (set-syntax-table emacs-lisp-mode-syntax-table)
 813                 (goto-char val-start-pos)
 814                 ;; The line below previously read as
 815                 ;; (delete-region (point) (progn (end-of-line) (point)))
 816                 ;; which suppressed display of the buffer local value for
 817                 ;; large values.
 818                 (when (looking-at "value is") (replace-match ""))
 819                 (save-excursion
 820                   (insert "\n\nValue:")
 821                   (set (make-local-variable 'help-button-cache)
 822                        (point-marker)))
 823                 (insert "value is shown ")
 824                 (insert-button "below"
 825                                'action help-button-cache
 826                                'follow-link t
 827                                'help-echo "mouse-2, RET: show value")
 828                 (insert ".\n")))
 829             (terpri)
 830
 831             (let* ((alias (condition-case nil
 832                               (indirect-variable variable)
 833                             (error variable)))
 834                    (obsolete (get variable 'byte-obsolete-variable))
 835                    (use (car obsolete))
 836                    (safe-var (get variable 'safe-local-variable))
 837                    (doc (or (documentation-property
 838                              variable 'variable-documentation)
 839                             (documentation-property
 840                              alias 'variable-documentation)))
 841                    (extra-line nil))
 842
 843               ;; Mention if it's a local variable.
 844               (cond
 845                ((and (local-variable-if-set-p variable)
 846                      (or (not (local-variable-p variable))
 847                          (with-temp-buffer
 848                            (local-variable-if-set-p variable))))
 849                 (setq extra-line t)
 850                 (princ "  Automatically becomes ")
 851                 (if permanent-local
 852                     (princ "permanently "))
 853                 (princ "buffer-local when set.\n"))
 854                ((not permanent-local))
 855                ((bufferp locus)
 856                 (setq extra-line t)
 857                 (princ "  This variable's buffer-local value is permanent.\n"))
 858                (t
 859                 (setq extra-line t)
 860                 (princ "  This variable's value is permanent \
 861 if it is given a local binding.\n")))
 862
 863               ;; Mention if it's an alias.
 864               (unless (eq alias variable)
 865                 (setq extra-line t)
 866                 (princ (format (substitute-command-keys
 867                                 "  This variable is an alias for ‘%s’.\n")
 868                                alias)))
 869
 870               (when obsolete
 871                 (setq extra-line t)
 872                 (princ "  This variable is obsolete")
 873                 (if (nth 2 obsolete)
 874                     (princ (format " since %s" (nth 2 obsolete))))
 875                 (princ (cond ((stringp use) (concat ";\n  " use))
 876                              (use (format (substitute-command-keys
 877                                            ";\n  use ‘%s’ instead.")
 878                                           (car obsolete)))
 879                              (t ".")))
 880                 (terpri))
 881
 882               (when (member (cons variable val)
 883                             (with-current-buffer buffer
 884                               file-local-variables-alist))
 885                 (setq extra-line t)
 886                 (if (member (cons variable val)
 887                              (with-current-buffer buffer
 888                                dir-local-variables-alist))
 889                     (let ((file (and (buffer-file-name buffer)
 890                                       (not (file-remote-p
 891                                             (buffer-file-name buffer)))
 892                                       (dir-locals-find-file
 893                                        (buffer-file-name buffer))))
 894                           (dir-file t))
 895                       (princ "  This variable's value is directory-local")
 896                       (if (null file)
 897                           (princ ".\n")
 898                         (princ ", set ")
 899                         (if (consp file) ; result from cache
 900                             ;; If the cache element has an mtime, we
 901                             ;; assume it came from a file.
 902                             (if (nth 2 file)
 903                                 (setq file (expand-file-name
 904                                             dir-locals-file (car file)))
 905                               ;; Otherwise, assume it was set directly.
 906                               (setq file (car file)
 907                                     dir-file nil)))
 908                         (princ (substitute-command-keys
 909                                 (if dir-file
 910                                     "by the file\n  ‘"
 911                                   "for the directory\n  ‘")))
 912                         (with-current-buffer standard-output
 913                           (insert-text-button
 914                            file 'type 'help-dir-local-var-def
 915                            'help-args (list variable file)))
 916                         (princ (substitute-command-keys "’.\n"))))
 917                   (princ "  This variable's value is file-local.\n")))
 918
 919               (when (memq variable ignored-local-variables)
 920                 (setq extra-line t)
 921                 (princ "  This variable is ignored as a file-local \
 922 variable.\n"))
 923
 924               ;; Can be both risky and safe, eg auto-fill-function.
 925               (when (risky-local-variable-p variable)
 926                 (setq extra-line t)
 927                 (princ "  This variable may be risky if used as a \
 928 file-local variable.\n")
 929                 (when (assq variable safe-local-variable-values)
 930                   (princ (substitute-command-keys
 931                           "  However, you have added it to \
 932 ‘safe-local-variable-values’.\n"))))
 933
 934               (when safe-var
 935                 (setq extra-line t)
 936                 (princ "  This variable is safe as a file local variable ")
 937                 (princ "if its value\n  satisfies the predicate ")
 938                 (princ (if (byte-code-function-p safe-var)
 939                            "which is a byte-compiled expression.\n"
 940                          (format (substitute-command-keys "‘%s’.\n")
 941                                  safe-var))))
 942
 943               (if extra-line (terpri))
 944               (princ "Documentation:\n")
 945               (with-current-buffer standard-output
 946                 (insert (or doc "Not documented as a variable."))))
 947
 948             ;; Make a link to customize if this variable can be customized.
 949             (when (custom-variable-p variable)
 950               (let ((customize-label "customize"))
 951                 (terpri)
 952                 (terpri)
 953                 (princ (concat "You can " customize-label " this variable."))
 954                 (with-current-buffer standard-output
 955                   (save-excursion
 956                     (re-search-backward
 957                      (concat "\\(" customize-label "\\)") nil t)
 958                     (help-xref-button 1 'help-customize-variable variable))))
 959               ;; Note variable's version or package version
 960               (let ((output (describe-variable-custom-version-info variable)))
 961                 (when output
 962                   (terpri)
 963                   (terpri)
 964                   (princ output))))
 965
 966             (with-current-buffer standard-output
 967               ;; Return the text we displayed.
 968               (buffer-string))))))))
 969
 970
 971 ;;;###autoload
 972 (defun describe-function-or-variable (symbol &optional buffer frame)
 973   "Display the full documentation of the function or variable SYMBOL.
 974 If SYMBOL is a variable and has a buffer-local value in BUFFER or FRAME
 975 \(default to the current buffer and current frame), it is displayed along
 976 with the global value."
 977   (interactive
 978    (let* ((v-or-f (variable-at-point))
 979           (found (symbolp v-or-f))
 980           (v-or-f (if found v-or-f (function-called-at-point)))
 981           (found (or found v-or-f))
 982           (enable-recursive-minibuffers t)
 983           val)
 984      (setq val (completing-read (if found
 985                                     (format
 986                                         "Describe function or variable (default %s): " v-or-f)
 987                                   "Describe function or variable: ")
 988                                 obarray
 989                                 (lambda (vv)
 990                                   (or (fboundp vv)
 991                                       (get vv 'variable-documentation)
 992                                       (and (boundp vv) (not (keywordp vv)))))
 993                                 t nil nil
 994                                 (if found (symbol-name v-or-f))))
 995      (list (if (equal val "")
 996                v-or-f (intern val)))))
 997   (if (not (symbolp symbol)) (message "You didn't specify a function or variable")
 998     (unless (buffer-live-p buffer) (setq buffer (current-buffer)))
 999     (unless (frame-live-p frame) (setq frame (selected-frame)))
1000     (help-xref-interned symbol buffer frame)))
1001
1002 ;;;###autoload
1003 (defun describe-syntax (&optional buffer)
1004   "Describe the syntax specifications in the syntax table of BUFFER.
1005 The descriptions are inserted in a help buffer, which is then displayed.
1006 BUFFER defaults to the current buffer."
1007   (interactive)
1008   (setq buffer (or buffer (current-buffer)))
1009   (help-setup-xref (list #'describe-syntax buffer)
1010                    (called-interactively-p 'interactive))
1011   (with-help-window (help-buffer)
1012     (let ((table (with-current-buffer buffer (syntax-table))))
1013       (with-current-buffer standard-output
1014         (describe-vector table 'internal-describe-syntax-value)
1015         (while (setq table (char-table-parent table))
1016           (insert "\nThe parent syntax table is:")
1017           (describe-vector table 'internal-describe-syntax-value))))))
1018
1019 (defun help-describe-category-set (value)
1020   (insert (cond
1021            ((null value) "default")
1022            ((char-table-p value) "deeper char-table ...")
1023            (t (condition-case nil
1024                   (category-set-mnemonics value)
1025                 (error "invalid"))))))
1026
1027 ;;;###autoload
1028 (defun describe-categories (&optional buffer)
1029   "Describe the category specifications in the current category table.
1030 The descriptions are inserted in a buffer, which is then displayed.
1031 If BUFFER is non-nil, then describe BUFFER's category table instead.
1032 BUFFER should be a buffer or a buffer name."
1033   (interactive)
1034   (setq buffer (or buffer (current-buffer)))
1035   (help-setup-xref (list #'describe-categories buffer)
1036                    (called-interactively-p 'interactive))
1037   (with-help-window (help-buffer)
1038     (let* ((table (with-current-buffer buffer (category-table)))
1039            (docs (char-table-extra-slot table 0)))
1040       (if (or (not (vectorp docs)) (/= (length docs) 95))
1041           (error "Invalid first extra slot in this category table\n"))
1042       (with-current-buffer standard-output
1043         (insert "Legend of category mnemonics (see the tail for the longer description)\n")
1044         (let ((pos (point)) (items 0) lines n)
1045           (dotimes (i 95)
1046             (if (aref docs i) (setq items (1+ items))))
1047           (setq lines (1+ (/ (1- items) 4)))
1048           (setq n 0)
1049           (dotimes (i 95)
1050             (let ((elt (aref docs i)))
1051               (when elt
1052                 (string-match ".*" elt)
1053                 (setq elt (match-string 0 elt))
1054                 (if (>= (length elt) 17)
1055                     (setq elt (concat (substring elt 0 14) "...")))
1056                 (if (< (point) (point-max))
1057                     (move-to-column (* 20 (/ n lines)) t))
1058                 (insert (+ i ?\s) ?: elt)
1059                 (if (< (point) (point-max))
1060                     (forward-line 1)
1061                   (insert "\n"))
1062                 (setq n (1+ n))
1063                 (if (= (% n lines) 0)
1064                     (goto-char pos))))))
1065         (goto-char (point-max))
1066         (insert "\n"
1067                 "character(s)\tcategory mnemonics\n"
1068                 "------------\t------------------")
1069         (describe-vector table 'help-describe-category-set)
1070         (insert "Legend of category mnemonics:\n")
1071         (dotimes (i 95)
1072           (let ((elt (aref docs i)))
1073             (when elt
1074               (if (string-match "\n" elt)
1075                   (setq elt (substring elt (match-end 0))))
1076               (insert (+ i ?\s) ": " elt "\n"))))
1077         (while (setq table (char-table-parent table))
1078           (insert "\nThe parent category table is:")
1079           (describe-vector table 'help-describe-category-set))))))
1080
1081 \f
1082 ;;; Replacements for old lib-src/ programs.  Don't seem especially useful.
1083
1084 ;; Replaces lib-src/digest-doc.c.
1085 ;;;###autoload
1086 (defun doc-file-to-man (file)
1087   "Produce an nroff buffer containing the doc-strings from the DOC file."
1088   (interactive (list (read-file-name "Name of DOC file: " doc-directory
1089                                      internal-doc-file-name t)))
1090   (or (file-readable-p file)
1091       (error "Cannot read file `%s'" file))
1092   (pop-to-buffer (generate-new-buffer "*man-doc*"))
1093   (setq buffer-undo-list t)
1094   (insert ".TH \"Command Summary for GNU Emacs\"\n"
1095           ".AU Richard M. Stallman\n")
1096   (insert-file-contents file)
1097   (let (notfirst)
1098     (while (search-forward "\x1f" nil 'move)
1099       (if (looking-at "S")
1100           (delete-region (1- (point)) (line-end-position))
1101         (delete-char -1)
1102         (if notfirst
1103             (insert "\n.DE\n")
1104           (setq notfirst t))
1105         (insert "\n.SH ")
1106         (insert (if (looking-at "F") "Function " "Variable "))
1107         (delete-char 1)
1108         (forward-line 1)
1109         (insert ".DS L\n"))))
1110   (insert "\n.DE\n")
1111   (setq buffer-undo-list nil)
1112   (nroff-mode))
1113
1114 ;; Replaces lib-src/sorted-doc.c.
1115 ;;;###autoload
1116 (defun doc-file-to-info (file)
1117   "Produce a texinfo buffer with sorted doc-strings from the DOC file."
1118   (interactive (list (read-file-name "Name of DOC file: " doc-directory
1119                                      internal-doc-file-name t)))
1120   (or (file-readable-p file)
1121       (error "Cannot read file `%s'" file))
1122   (let ((i 0) type name doc alist)
1123     (with-temp-buffer
1124       (insert-file-contents file)
1125       ;; The characters "@{}" need special treatment.
1126       (while (re-search-forward "[@{}]" nil t)
1127         (backward-char)
1128         (insert "@")
1129         (forward-char 1))
1130       (goto-char (point-min))
1131       (while (search-forward "\x1f" nil t)
1132         (unless (looking-at "S")
1133           (setq type (char-after)
1134                 name (buffer-substring (1+ (point)) (line-end-position))
1135                 doc (buffer-substring (line-beginning-position 2)
1136                                       (if (search-forward  "\x1f" nil 'move)
1137                                           (1- (point))
1138                                         (point)))
1139                 alist (cons (list name type doc) alist))
1140           (backward-char 1))))
1141     (pop-to-buffer (generate-new-buffer "*info-doc*"))
1142     (setq buffer-undo-list t)
1143     ;; Write the output header.
1144     (insert "\\input texinfo  @c -*-texinfo-*-\n"
1145             "@setfilename emacsdoc.info\n"
1146             "@settitle Command Summary for GNU Emacs\n"
1147             "@finalout\n"
1148             "\n@node Top\n"
1149             "@unnumbered Command Summary for GNU Emacs\n\n"
1150             "@table @asis\n\n"
1151             "@iftex\n"
1152             "@global@let@ITEM@item\n"
1153             "@def@item{@filbreak@vskip5pt@ITEM}\n"
1154             "@font@tensy cmsy10 scaled @magstephalf\n"
1155             "@font@teni cmmi10 scaled @magstephalf\n"
1156             "@def\\{{@tensy@char110}}\n" ; this backslash goes with cmr10
1157             "@def|{{@tensy@char106}}\n"
1158             "@def@{{{@tensy@char102}}\n"
1159             "@def@}{{@tensy@char103}}\n"
1160             "@def<{{@teni@char62}}\n"
1161             "@def>{{@teni@char60}}\n"
1162             "@chardef@@64\n"
1163             "@catcode43=12\n"
1164             "@tableindent-0.2in\n"
1165             "@end iftex\n")
1166     ;; Sort the array by name; within each name, by type (functions first).
1167     (setq alist (sort alist (lambda (e1 e2)
1168                               (if (string-equal (car e1) (car e2))
1169                                   (<= (cadr e1) (cadr e2))
1170                                 (string-lessp (car e1) (car e2))))))
1171     ;; Print each function.
1172     (dolist (e alist)
1173       (insert "\n@item "
1174               (if (char-equal (cadr e) ?\F) "Function" "Variable")
1175               " @code{" (car e) "}\n@display\n"
1176               (nth 2 e)
1177               "\n@end display\n")
1178       ;; Try to avoid a save size overflow in the TeX output routine.
1179       (if (zerop (setq i (% (1+ i) 100)))
1180           (insert "\n@end table\n@table @asis\n")))
1181     (insert "@end table\n"
1182             "@bye\n")
1183     (setq buffer-undo-list nil)
1184     (texinfo-mode)))
1185
1186 (provide 'help-fns)
1187
1188 ;;; help-fns.el ends here