lisp/apropos.el

   1 ;;; apropos.el --- apropos commands for users and programmers.
   2
   3 ;; Copyright (C) 1989, 1994, 1995 Free Software Foundation, Inc.
   4
   5 ;; Author: Joe Wells <jbw@bigbird.bu.edu>
   6 ;; Rewritten: Daniel Pfeiffer <occitan@esperanto.org>
   7 ;; Keywords: help
   8
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software; you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation; either version 2, or (at your option)
  14 ;; any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  23 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  24 ;; Boston, MA 02111-1307, USA.
  25
  26 ;;; Commentary:
  27
  28 ;; The ideas for this package were derived from the C code in
  29 ;; src/keymap.c and elsewhere.  The functions in this file should
  30 ;; always be byte-compiled for speed.  Someone should rewrite this in
  31 ;; C (as part of src/keymap.c) for speed.
  32
  33 ;; The idea for super-apropos is based on the original implementation
  34 ;; by Lynn Slater <lrs@esl.com>.
  35
  36 ;; History:
  37 ;; Fixed bug, current-local-map can return nil.
  38 ;; Change, doesn't calculate key-bindings unless needed.
  39 ;; Added super-apropos capability, changed print functions.
  40 ;;; Made fast-apropos and super-apropos share code.
  41 ;;; Sped up fast-apropos again.
  42 ;; Added apropos-do-all option.
  43 ;;; Added fast-command-apropos.
  44 ;; Changed doc strings to comments for helping functions.
  45 ;;; Made doc file buffer read-only, buried it.
  46 ;; Only call substitute-command-keys if do-all set.
  47
  48 ;; Optionally use configurable faces to make the output more legible.
  49 ;; Differentiate between command, function and macro.
  50 ;; Apropos-command (ex command-apropos) does cmd and optionally user var.
  51 ;; Apropos shows all 3 aspects of symbols (fn, var and plist)
  52 ;; Apropos-documentation (ex super-apropos) now finds all it should.
  53 ;; New apropos-value snoops through all values and optionally plists.
  54 ;; Reading DOC file doesn't load nroff.
  55 ;; Added hypertext following of documentation, mouse-2 on variable gives value
  56 ;;   from buffer in active window.
  57
  58 ;;; Code:
  59
  60 (defgroup apropos nil
  61   "Apropos commands for users and programmers"
  62   :group 'help
  63   :prefix "apropos")
  64
  65 ;; I see a degradation of maybe 10-20% only.
  66 (defcustom apropos-do-all nil
  67   "*Whether the apropos commands should do more.
  68
  69 Slows them down more or less.  Set this non-nil if you have a fast machine."
  70   :group 'apropos
  71   :type 'boolean)
  72
  73
  74 (defcustom apropos-symbol-face 'bold
  75   "*Face for symbol name in Apropos output, or nil for none."
  76   :group 'apropos
  77   :type 'face)
  78
  79 (defcustom apropos-keybinding-face 'underline
  80   "*Face for lists of keybinding in Apropos output, or nil for none."
  81   :group 'apropos
  82   :type 'face)
  83
  84 (defcustom apropos-label-face 'italic
  85   "*Face for label (`Command', `Variable' ...) in Apropos output.
  86 A value of nil means don't use any special font for them, and also
  87 turns off mouse highlighting."
  88   :group 'apropos
  89   :type 'face)
  90
  91 (defcustom apropos-property-face 'bold-italic
  92   "*Face for property name in apropos output, or nil for none."
  93   :group 'apropos
  94   :type 'face)
  95
  96 (defcustom apropos-match-face 'secondary-selection
  97   "*Face for matching text in Apropos documentation/value, or nil for none.
  98 This applies when you look for matches in the documentation or variable value
  99 for the regexp; the part that matches gets displayed in this font."
 100   :group 'apropos
 101   :type 'face)
 102
 103
 104 (defvar apropos-mode-map
 105   (let ((map (make-sparse-keymap)))
 106     (define-key map "\C-m" 'apropos-follow)
 107     (define-key map " "    'scroll-up)
 108     (define-key map "\177" 'scroll-down)
 109     (define-key map "q"    'quit-window)
 110     (define-key map [mouse-2] 'apropos-mouse-follow)
 111     (define-key map [down-mouse-2] nil)
 112     map)
 113   "Keymap used in Apropos mode.")
 114
 115 (defvar apropos-mode-hook nil
 116   "*Hook run when mode is turned on.")
 117
 118 (defvar apropos-regexp nil
 119   "Regexp used in current apropos run.")
 120
 121 (defvar apropos-files-scanned ()
 122   "List of elc files already scanned in current run of `apropos-documentation'.")
 123
 124 (defvar apropos-accumulator ()
 125   "Alist of symbols already found in current apropos run.")
 126
 127 (defvar apropos-item ()
 128   "Current item in or for `apropos-accumulator'.")
 129 \f
 130 ;;;###autoload
 131 (defun apropos-mode ()
 132   "Major mode for following hyperlinks in output of apropos commands.
 133
 134 \\{apropos-mode-map}"
 135   (interactive)
 136   (kill-all-local-variables)
 137   (use-local-map apropos-mode-map)
 138   (setq major-mode 'apropos-mode
 139         mode-name "Apropos")
 140   (run-hooks 'apropos-mode-hook))
 141
 142 ;;;###autoload
 143 (defun apropos-variable (regexp &optional do-all)
 144   "Show user variables that match REGEXP.
 145 With optional prefix DO-ALL or if `apropos-do-all' is non-nil, also show
 146 normal variables."
 147   (interactive (list (read-string
 148                       (concat "Apropos "
 149                               (if (or current-prefix-arg apropos-do-all)
 150                                   "variable"
 151                                 "user option")
 152                               " (regexp): "))
 153                      current-prefix-arg))
 154   (apropos-command regexp nil
 155                    (if (or do-all apropos-do-all)
 156                        #'(lambda (symbol)
 157                            (and (boundp symbol)
 158                                 (get symbol 'variable-documentation)))
 159                      'user-variable-p)))
 160
 161 ;; For auld lang syne:
 162 ;;;###autoload
 163 (fset 'command-apropos 'apropos-command)
 164 ;;;###autoload
 165 (defun apropos-command (apropos-regexp &optional do-all var-predicate)
 166   "Show commands (interactively callable functions) that match APROPOS-REGEXP.
 167 With optional prefix DO-ALL, or if `apropos-do-all' is non-nil, also show
 168 noninteractive functions.
 169
 170 If VAR-PREDICATE is non-nil, show only variables, and only those that
 171 satisfy the predicate VAR-PREDICATE."
 172   (interactive (list (read-string (concat
 173                                    "Apropos command "
 174                                    (if (or current-prefix-arg
 175                                            apropos-do-all)
 176                                        "or function ")
 177                                    "(regexp): "))
 178                      current-prefix-arg))
 179   (let ((message
 180          (let ((standard-output (get-buffer-create "*Apropos*")))
 181            (print-help-return-message 'identity))))
 182     (or do-all (setq do-all apropos-do-all))
 183     (setq apropos-accumulator
 184           (apropos-internal apropos-regexp
 185                             (or var-predicate
 186                                 (if do-all 'functionp 'commandp))))
 187     (let ((tem apropos-accumulator))
 188       (while tem
 189         (if (get (car tem) 'apropos-inhibit)
 190             (setq apropos-accumulator (delq (car tem) apropos-accumulator)))
 191         (setq tem (cdr tem))))
 192     (let ((p apropos-accumulator)
 193           doc symbol)
 194       (while p
 195         (setcar p (list
 196                    (setq symbol (car p))
 197                    (unless var-predicate
 198                      (if (functionp symbol)
 199                          (if (setq doc (documentation symbol t))
 200                              (substring doc 0 (string-match "\n" doc))
 201                            "(not documented)")))
 202                    (and var-predicate
 203                         (funcall var-predicate symbol)
 204                         (if (setq doc (documentation-property
 205                                        symbol 'variable-documentation t))
 206                             (substring doc 0
 207                                        (string-match "\n" doc))))))
 208         (setq p (cdr p))))
 209     (and (apropos-print t nil)
 210          message
 211          (message message))))
 212
 213
 214 ;;;###autoload
 215 (defun apropos (apropos-regexp &optional do-all)
 216   "Show all bound symbols whose names match APROPOS-REGEXP.
 217 With optional prefix DO-ALL or if `apropos-do-all' is non-nil, also
 218 show unbound symbols and key bindings, which is a little more
 219 time-consuming.  Returns list of symbols and documentation found."
 220   (interactive "sApropos symbol (regexp): \nP")
 221   (setq apropos-accumulator
 222         (apropos-internal apropos-regexp
 223                           (and (not do-all)
 224                                (not apropos-do-all)
 225                                (lambda (symbol)
 226                                  (or (fboundp symbol)
 227                                      (boundp symbol)
 228                                      (facep symbol)
 229                                      (symbol-plist symbol))))))
 230   (let ((tem apropos-accumulator))
 231     (while tem
 232       (if (get (car tem) 'apropos-inhibit)
 233           (setq apropos-accumulator (delq (car tem) apropos-accumulator)))
 234       (setq tem (cdr tem))))
 235   (let ((p apropos-accumulator)
 236         symbol doc properties)
 237     (while p
 238       (setcar p (list
 239                  (setq symbol (car p))
 240                  (when (fboundp symbol)
 241                    (if (setq doc (condition-case nil
 242                                      (documentation symbol t)
 243                                    (void-function
 244                                     "(alias for undefined function)")))
 245                        (substring doc 0 (string-match "\n" doc))
 246                      "(not documented)"))
 247                  (when (boundp symbol)
 248                    (if (setq doc (documentation-property
 249                                   symbol 'variable-documentation t))
 250                        (substring doc 0 (string-match "\n" doc))
 251                      "(not documented)"))
 252                  (when (setq properties (symbol-plist symbol))
 253                    (setq doc (list (car properties)))
 254                    (while (setq properties (cdr (cdr properties)))
 255                      (setq doc (cons (car properties) doc)))
 256                    (mapconcat #'symbol-name (nreverse doc) " "))
 257                  (when (get symbol 'widget-type)
 258                    (if (setq doc (documentation-property
 259                                   symbol 'widget-documentation t))
 260                        (substring doc 0
 261                                   (string-match "\n" doc))
 262                      "(not documented)"))
 263                  (when (facep symbol)
 264                    (if (setq doc (documentation-property
 265                                   symbol 'face-documentation t))
 266                        (substring doc 0
 267                                   (string-match "\n" doc))
 268                      "(not documented)"))
 269                  (when (get symbol 'custom-group)
 270                    (if (setq doc (documentation-property
 271                                   symbol 'group-documentation t))
 272                        (substring doc 0
 273                                   (string-match "\n" doc))
 274                      "(not documented)"))))
 275       (setq p (cdr p))))
 276   (apropos-print
 277    (or do-all apropos-do-all)
 278    nil))
 279
 280
 281 ;;;###autoload
 282 (defun apropos-value (apropos-regexp &optional do-all)
 283   "Show all symbols whose value's printed image matches APROPOS-REGEXP.
 284 With optional prefix DO-ALL or if `apropos-do-all' is non-nil, also looks
 285 at the function and at the names and values of properties.
 286 Returns list of symbols and values found."
 287   (interactive "sApropos value (regexp): \nP")
 288   (or do-all (setq do-all apropos-do-all))
 289   (setq apropos-accumulator ())
 290    (let (f v p)
 291      (mapatoms
 292       (lambda (symbol)
 293         (setq f nil v nil p nil)
 294         (or (memq symbol '(apropos-regexp do-all apropos-accumulator
 295                                           symbol f v p))
 296             (setq v (apropos-value-internal 'boundp symbol 'symbol-value)))
 297         (if do-all
 298             (setq f (apropos-value-internal 'fboundp symbol 'symbol-function)
 299                   p (apropos-format-plist symbol "\n    " t)))
 300         (if (or f v p)
 301             (setq apropos-accumulator (cons (list symbol f v p)
 302                                             apropos-accumulator))))))
 303   (apropos-print nil t))
 304
 305
 306 ;;;###autoload
 307 (defun apropos-documentation (apropos-regexp &optional do-all)
 308   "Show symbols whose documentation contain matches for APROPOS-REGEXP.
 309 With optional prefix DO-ALL or if `apropos-do-all' is non-nil, also use
 310 documentation that is not stored in the documentation file and show key
 311 bindings.
 312 Returns list of symbols and documentation found."
 313   (interactive "sApropos documentation (regexp): \nP")
 314   (or do-all (setq do-all apropos-do-all))
 315   (setq apropos-accumulator () apropos-files-scanned ())
 316   (let ((standard-input (get-buffer-create " apropos-temp"))
 317         f v)
 318     (unwind-protect
 319         (save-excursion
 320           (set-buffer standard-input)
 321           (apropos-documentation-check-doc-file)
 322           (if do-all
 323               (mapatoms
 324                (lambda (symbol)
 325                  (setq f (apropos-safe-documentation symbol)
 326                        v (get symbol 'variable-documentation))
 327                  (if (integerp v) (setq v))
 328                  (setq f (apropos-documentation-internal f)
 329                        v (apropos-documentation-internal v))
 330                  (if (or f v)
 331                      (if (setq apropos-item
 332                                (cdr (assq symbol apropos-accumulator)))
 333                          (progn
 334                            (if f
 335                                (setcar apropos-item f))
 336                            (if v
 337                                (setcar (cdr apropos-item) v)))
 338                        (setq apropos-accumulator
 339                              (cons (list symbol f v)
 340                                    apropos-accumulator)))))))
 341           (apropos-print nil t))
 342       (kill-buffer standard-input))))
 343
 344 \f
 345 (defun apropos-value-internal (predicate symbol function)
 346   (if (funcall predicate symbol)
 347       (progn
 348         (setq symbol (prin1-to-string (funcall function symbol)))
 349         (if (string-match apropos-regexp symbol)
 350             (progn
 351               (if apropos-match-face
 352                   (put-text-property (match-beginning 0) (match-end 0)
 353                                      'face apropos-match-face
 354                                      symbol))
 355               symbol)))))
 356
 357 (defun apropos-documentation-internal (doc)
 358   (if (consp doc)
 359       (apropos-documentation-check-elc-file (car doc))
 360     (and doc
 361          (string-match apropos-regexp doc)
 362          (progn
 363            (if apropos-match-face
 364                (put-text-property (match-beginning 0)
 365                                   (match-end 0)
 366                                   'face apropos-match-face
 367                                   (setq doc (copy-sequence doc))))
 368            doc))))
 369
 370 (defun apropos-format-plist (pl sep &optional compare)
 371   (setq pl (symbol-plist pl))
 372   (let (p p-out)
 373     (while pl
 374       (setq p (format "%s %S" (car pl) (nth 1 pl)))
 375       (if (or (not compare) (string-match apropos-regexp p))
 376           (if apropos-property-face
 377               (put-text-property 0 (length (symbol-name (car pl)))
 378                                  'face apropos-property-face p))
 379         (setq p nil))
 380       (if p
 381           (progn
 382             (and compare apropos-match-face
 383                  (put-text-property (match-beginning 0) (match-end 0)
 384                                     'face apropos-match-face
 385                                     p))
 386             (setq p-out (concat p-out (if p-out sep) p))))
 387       (setq pl (nthcdr 2 pl)))
 388     p-out))
 389
 390
 391 ;; Finds all documentation related to APROPOS-REGEXP in internal-doc-file-name.
 392
 393 (defun apropos-documentation-check-doc-file ()
 394   (let (type symbol (sepa 2) sepb beg end)
 395     (insert ?\^_)
 396     (backward-char)
 397     (insert-file-contents (concat doc-directory internal-doc-file-name))
 398     (forward-char)
 399     (while (save-excursion
 400              (setq sepb (search-forward "\^_"))
 401              (not (eobp)))
 402       (beginning-of-line 2)
 403       (if (save-restriction
 404             (narrow-to-region (point) (1- sepb))
 405             (re-search-forward apropos-regexp nil t))
 406           (progn
 407             (setq beg (match-beginning 0)
 408                   end (point))
 409             (goto-char (1+ sepa))
 410             (or (setq type (if (eq ?F (preceding-char))
 411                                1        ; function documentation
 412                              2)         ; variable documentation
 413                       symbol (read)
 414                       beg (- beg (point) 1)
 415                       end (- end (point) 1)
 416                       doc (buffer-substring (1+ (point)) (1- sepb))
 417                       apropos-item (assq symbol apropos-accumulator))
 418                 (setq apropos-item (list symbol nil nil)
 419                       apropos-accumulator (cons apropos-item
 420                                                 apropos-accumulator)))
 421             (if apropos-match-face
 422                 (put-text-property beg end 'face apropos-match-face doc))
 423             (setcar (nthcdr type apropos-item) doc)))
 424       (setq sepa (goto-char sepb)))))
 425
 426 (defun apropos-documentation-check-elc-file (file)
 427   (if (member file apropos-files-scanned)
 428       nil
 429     (let (symbol doc beg end this-is-a-variable)
 430       (setq apropos-files-scanned (cons file apropos-files-scanned))
 431       (erase-buffer)
 432       (insert-file-contents file)
 433       (while (search-forward "\n#@" nil t)
 434         ;; Read the comment length, and advance over it.
 435         (setq end (read)
 436               beg (1+ (point))
 437               end (+ (point) end -1))
 438         (forward-char)
 439         (if (save-restriction
 440               ;; match ^ and $ relative to doc string
 441               (narrow-to-region beg end)
 442               (re-search-forward apropos-regexp nil t))
 443             (progn
 444               (goto-char (+ end 2))
 445               (setq doc (buffer-substring beg end)
 446                     end (- (match-end 0) beg)
 447                     beg (- (match-beginning 0) beg)
 448                     this-is-a-variable (looking-at "(def\\(var\\|const\\) ")
 449                     symbol (progn
 450                              (skip-chars-forward "(a-z")
 451                              (forward-char)
 452                              (read))
 453                     symbol (if (consp symbol)
 454                                (nth 1 symbol)
 455                              symbol))
 456               (if (if this-is-a-variable
 457                       (get symbol 'variable-documentation)
 458                     (and (fboundp symbol) (apropos-safe-documentation symbol)))
 459                   (progn
 460                     (or (setq apropos-item (assq symbol apropos-accumulator))
 461                         (setq apropos-item (list symbol nil nil)
 462                               apropos-accumulator (cons apropos-item
 463                                                         apropos-accumulator)))
 464                     (if apropos-match-face
 465                         (put-text-property beg end 'face apropos-match-face
 466                                            doc))
 467                     (setcar (nthcdr (if this-is-a-variable 2 1)
 468                                     apropos-item)
 469                             doc)))))))))
 470
 471
 472
 473 (defun apropos-safe-documentation (function)
 474   "Like `documentation', except it avoids calling `get_doc_string'.
 475 Will return nil instead."
 476   (while (and function (symbolp function))
 477     (setq function (if (fboundp function)
 478                        (symbol-function function))))
 479   (if (eq (car-safe function) 'macro)
 480       (setq function (cdr function)))
 481   (setq function (if (byte-code-function-p function)
 482                      (if (> (length function) 4)
 483                          (aref function 4))
 484                    (if (eq (car-safe function) 'autoload)
 485                        (nth 2 function)
 486                      (if (eq (car-safe function) 'lambda)
 487                          (if (stringp (nth 2 function))
 488                              (nth 2 function)
 489                            (if (stringp (nth 3 function))
 490                                (nth 3 function)))))))
 491   (if (integerp function)
 492       nil
 493     function))
 494
 495
 496
 497 (defvar apropos-label-properties nil
 498   "List of face properties to use for a label.
 499 Bound by `apropos-print' for use by `apropos-print-doc'.")
 500
 501 (defun apropos-print (do-keys spacing)
 502   "Output result of apropos searching into buffer `*Apropos*'.
 503 The value of `apropos-accumulator' is the list of items to output.
 504 Each element should have the format (SYMBOL FN-DOC VAR-DOC [PLIST-DOC]).
 505 The return value is the list that was in `apropos-accumulator', sorted
 506 alphabetically by symbol name; but this function also sets
 507 `apropos-accumulator' to nil before returning."
 508   (if (null apropos-accumulator)
 509       (message "No apropos matches for `%s'" apropos-regexp)
 510     (setq apropos-accumulator
 511           (sort apropos-accumulator (lambda (a b)
 512                                       (string-lessp (car a) (car b)))))
 513     (setq apropos-label-properties
 514           (if (and apropos-label-face
 515                    (symbolp apropos-label-face))
 516               `(face ,apropos-label-face
 517                      mouse-face highlight)))
 518     (with-output-to-temp-buffer "*Apropos*"
 519       (let ((p apropos-accumulator)
 520             (old-buffer (current-buffer))
 521             symbol item point1 point2)
 522         (set-buffer standard-output)
 523         (apropos-mode)
 524         (if (display-mouse-p)
 525             (insert "If you move the mouse over text that changes color,\n"
 526                     (substitute-command-keys
 527                      "you can click \\[apropos-mouse-follow] to get more information.\n")))
 528         (insert (substitute-command-keys
 529                  "In this buffer, type \\[apropos-follow] to get full documentation.\n\n"))
 530         (while (consp p)
 531           (or (not spacing) (bobp) (terpri))
 532           (setq apropos-item (car p)
 533                 symbol (car apropos-item)
 534                 p (cdr p)
 535                 point1 (point))
 536           (princ symbol)                        ; print symbol name
 537           (setq point2 (point))
 538           ;; Calculate key-bindings if we want them.
 539           (and do-keys
 540                (commandp symbol)
 541                (indent-to 30 1)
 542                (if (let ((keys
 543                           (save-excursion
 544                             (set-buffer old-buffer)
 545                             (where-is-internal symbol)))
 546                          filtered)
 547                      ;; Copy over the list of key sequences,
 548                      ;; omitting any that contain a buffer or a frame.
 549                      (while keys
 550                        (let ((key (car keys))
 551                              (i 0)
 552                              loser)
 553                          (while (< i (length key))
 554                            (if (or (framep (aref key i))
 555                                    (bufferp (aref key i)))
 556                                (setq loser t))
 557                            (setq i (1+ i)))
 558                          (or loser
 559                              (setq filtered (cons key filtered))))
 560                        (setq keys (cdr keys)))
 561                      (setq item filtered))
 562                    ;; Convert the remaining keys to a string and insert.
 563                    (insert
 564                     (mapconcat
 565                      (lambda (key)
 566                        (setq key (condition-case ()
 567                                      (key-description key)
 568                                    (error)))
 569                        (if apropos-keybinding-face
 570                            (put-text-property 0 (length key)
 571                                               'face apropos-keybinding-face
 572                                               key))
 573                        key)
 574                      item ", "))
 575                  (insert "M-x")
 576                  (put-text-property (- (point) 3) (point)
 577                                     'face apropos-keybinding-face)
 578                  (insert " " (symbol-name symbol) " ")
 579                  (insert "RET")
 580                  (put-text-property (- (point) 3) (point)
 581                                     'face apropos-keybinding-face)))
 582           (terpri)
 583           ;; only now so we don't propagate text attributes all over
 584           (put-text-property point1 point2 'item
 585                              (if (eval `(or ,@(cdr apropos-item)))
 586                                  (car apropos-item)
 587                                apropos-item))
 588           (if apropos-symbol-face
 589               (put-text-property point1 point2 'face apropos-symbol-face))
 590           (apropos-print-doc 'describe-function 1
 591                              (if (commandp symbol)
 592                                  "Command"
 593                                (if (apropos-macrop symbol)
 594                                    "Macro"
 595                                  "Function"))
 596                              t)
 597           ;; We used to use `customize-variable-other-window' instead
 598           ;; for a customizable variable, but that is slow.
 599           ;; It is better to show an ordinary help buffer
 600           ;; and let the user click on the customization button
 601           ;; in that buffer, if he wants to.
 602           ;; Likewise for `customize-face-other-window'.
 603           (apropos-print-doc 'describe-variable 2 "Variable" t)
 604           (apropos-print-doc 'customize-group-other-window 6 "Group" t)
 605           (apropos-print-doc 'describe-face 5 "Face" t)
 606           (apropos-print-doc 'widget-browse-other-window 4 "Widget" t)
 607           (apropos-print-doc 'apropos-describe-plist 3
 608                              "Plist" nil))
 609         (setq buffer-read-only t))))
 610   (prog1 apropos-accumulator
 611     (setq apropos-accumulator ())))     ; permit gc
 612
 613
 614 (defun apropos-macrop (symbol)
 615   "T if SYMBOL is a Lisp macro."
 616   (and (fboundp symbol)
 617        (consp (setq symbol
 618                     (symbol-function symbol)))
 619        (or (eq (car symbol) 'macro)
 620            (if (eq (car symbol) 'autoload)
 621                (memq (nth 4 symbol)
 622                      '(macro t))))))
 623
 624
 625 (defun apropos-print-doc (action i str do-keys)
 626   (if (stringp (setq i (nth i apropos-item)))
 627       (progn
 628         (insert "  ")
 629         (put-text-property (- (point) 2) (1- (point))
 630                            'action action)
 631         (insert str ": ")
 632         (if apropos-label-properties
 633             (add-text-properties (- (point) (length str) 2)
 634                                  (1- (point))
 635                                  apropos-label-properties))
 636         (insert (if do-keys (substitute-command-keys i) i))
 637         (or (bolp) (terpri)))))
 638
 639
 640 (defun apropos-mouse-follow (event)
 641   (interactive "e")
 642   (let ((other (if (eq (current-buffer) (get-buffer "*Apropos*"))
 643                    ()
 644                  (current-buffer))))
 645     (save-excursion
 646       (set-buffer (window-buffer (posn-window (event-start event))))
 647       (goto-char (posn-point (event-start event)))
 648       (or (and (not (eobp)) (get-text-property (point) 'mouse-face))
 649           (and (not (bobp)) (get-text-property (1- (point)) 'mouse-face))
 650           (error "There is nothing to follow here"))
 651       (apropos-follow other))))
 652
 653
 654 (defun apropos-follow (&optional other)
 655   (interactive)
 656   (let* (;; Properties are always found at the beginning of the line.
 657          (bol (save-excursion (beginning-of-line) (point)))
 658          ;; If there is no `item' property here, look behind us.
 659          (item (get-text-property bol 'item))
 660          (item-at (if item nil (previous-single-property-change bol 'item)))
 661          ;; Likewise, if there is no `action' property here, look in front.
 662          (action (get-text-property bol 'action))
 663          (action-at (if action nil (next-single-property-change bol 'action))))
 664     (and (null item) item-at
 665          (setq item (get-text-property (1- item-at) 'item)))
 666     (and (null action) action-at
 667          (setq action (get-text-property action-at 'action)))
 668     (if (not (and item action))
 669         (error "There is nothing to follow here"))
 670     (if (consp item) (error "There is nothing to follow in `%s'" (car item)))
 671     (if other (set-buffer other))
 672     (funcall action item)))
 673
 674
 675
 676 (defun apropos-describe-plist (symbol)
 677   "Display a pretty listing of SYMBOL's plist."
 678   (with-output-to-temp-buffer "*Help*"
 679     (set-buffer standard-output)
 680     (princ "Symbol ")
 681     (prin1 symbol)
 682     (princ "'s plist is\n (")
 683     (if apropos-symbol-face
 684         (put-text-property 8 (- (point) 14) 'face apropos-symbol-face))
 685     (insert (apropos-format-plist symbol "\n  "))
 686     (princ ")")
 687     (print-help-return-message)))
 688
 689 (provide 'apropos)
 690
 691 ;;; apropos.el ends here