lisp/apropos.el

   1 ;;; apropos.el --- faster apropos commands.
   2
   3 ;; Copyright (C) 1989 Free Software Foundation, Inc.
   4
   5 ;; Author: Joe Wells <jbw@bigbird.bu.edu>
   6 ;; Keywords: help
   7
   8 ;; This file is part of GNU Emacs.
   9
  10 ;; GNU Emacs is free software; you can redistribute it and/or modify
  11 ;; it under the terms of the GNU General Public License as published by
  12 ;; the Free Software Foundation; either version 2, or (at your option)
  13 ;; any later version.
  14
  15 ;; GNU Emacs is distributed in the hope that it will be useful,
  16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ;; GNU General Public License for more details.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs; see the file COPYING.  If not, write to
  22 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  23
  24 ;;; Commentary:
  25
  26 ;; The ideas for this package were derived from the C code in
  27 ;; src/keymap.c and elsewhere.  The functions in this file should
  28 ;; always be byte-compiled for speed.  Someone should rewrite this in
  29 ;; C (as part of src/keymap.c) for speed.
  30
  31 ;; The idea for super-apropos is based on the original implementation
  32 ;; by Lynn Slater <lrs@esl.com>.
  33
  34 ;; History:
  35 ;; Fixed bug, current-local-map can return nil.
  36 ;; Change, doesn't calculate key-bindings unless needed.
  37 ;; Added super-apropos capability, changed print functions.
  38 ;; Made fast-apropos and super-apropos share code.
  39 ;; Sped up fast-apropos again.
  40 ;; Added apropos-do-all option.
  41 ;; Added fast-command-apropos.
  42 ;; Changed doc strings to comments for helping functions.
  43 ;; Made doc file buffer read-only, buried it.
  44 ;; Only call substitute-command-keys if do-all set.
  45
  46 ;;; Code:
  47
  48 (defvar apropos-do-all nil
  49   "*Whether `apropos' and `super-apropos' should do everything that they can.
  50 Makes them run 2 or 3 times slower.  Set this non-nil if you have a fast
  51 machine.")
  52
  53 ;;;###autoload
  54 (defun apropos (regexp &optional do-all pred)
  55   "Show all symbols whose names contain matches for REGEXP.
  56 If optional argument DO-ALL is non-nil (prefix argument if interactive),
  57 or if `apropos-do-all' is non-nil, does more (time-consuming) work such as
  58 showing key bindings.  Optional argument PRED is called with each symbol, and
  59 if it returns nil, the symbol is not shown.
  60
  61 Returns list of symbols and documentation found."
  62   (interactive "sApropos (regexp): \nP")
  63   (setq do-all (or apropos-do-all do-all))
  64   (let ((apropos-accumulate (apropos-internal regexp pred)))
  65     (if (null apropos-accumulate)
  66         (message "No apropos matches for `%s'" regexp)
  67       (apropos-get-doc apropos-accumulate)
  68       (with-output-to-temp-buffer "*Help*"
  69         (apropos-print-matches apropos-accumulate regexp nil do-all)))
  70     apropos-accumulate))
  71
  72 ;; If "C-h a" still has its original binding of command-apropos, change it to
  73 ;; use fast-command-apropos.  I don't use substitute-key-definition because
  74 ;; it's slow.
  75 ;(if (eq 'command-apropos (lookup-key help-map "a"))
  76 ;    (define-key help-map "a" 'fast-command-apropos))
  77
  78 ;; Takes LIST of symbols and adds documentation.  Modifies LIST in place.
  79 ;; Resulting alist is of form ((symbol fn-doc var-doc) ...).  Should only be
  80 ;; called by apropos.  Returns LIST.
  81
  82 (defun apropos-get-doc (list)
  83   (let ((p list)
  84         fn-doc var-doc symbol)
  85     (while (consp p)
  86       (setq symbol (car p)
  87             fn-doc (and (fboundp symbol)
  88                         (documentation symbol))
  89             var-doc (documentation-property symbol 'variable-documentation)
  90             fn-doc (and fn-doc
  91                         (substring fn-doc 0 (string-match "\n" fn-doc)))
  92             var-doc (and var-doc
  93                          (substring var-doc 0 (string-match "\n" var-doc))))
  94       (setcar p (list symbol fn-doc var-doc))
  95       (setq p (cdr p)))
  96     list))
  97
  98 ;;;###autoload
  99 (defun super-apropos (regexp &optional do-all)
 100   "Show symbols whose names/documentation contain matches for REGEXP.
 101 If optional argument DO-ALL is non-nil (prefix argument if interactive),
 102 or if `apropos-do-all' is non-nil, does more (time-consuming) work such as
 103 showing key bindings and documentation that is not stored in the documentation
 104 file.
 105
 106 Returns list of symbols and documentation found."
 107   (interactive "sSuper Apropos: \nP")
 108   (setq do-all (or apropos-do-all do-all))
 109   (let (apropos-accumulate fn-doc var-doc item)
 110     (setq apropos-accumulate (super-apropos-check-doc-file regexp))
 111     (if (null apropos-accumulate)
 112         (message "No apropos matches for `%s'" regexp)
 113       (if do-all (mapatoms 'super-apropos-accumulate))
 114       (with-output-to-temp-buffer "*Help*"
 115         (apropos-print-matches apropos-accumulate nil t do-all)))
 116     apropos-accumulate))
 117
 118 ;; Finds all documentation related to REGEXP in internal-doc-file-name.
 119 ;; Returns an alist of form ((symbol fn-doc var-doc) ...).
 120
 121 (defun super-apropos-check-doc-file (regexp)
 122   (let* ((doc-file (concat doc-directory internal-doc-file-name))
 123          (doc-buffer (find-file-noselect doc-file t))
 124         ;;      (doc-buffer (or (get-file-buffer doc-file)
 125         ;;                      (find-file-noselect doc-file)))
 126         type symbol doc sym-list)
 127     (save-excursion
 128       (set-buffer doc-buffer)
 129       ;; a user said he might accidentally edit the doc file
 130       (setq buffer-read-only t)
 131       (bury-buffer doc-buffer)
 132       (goto-char (point-min))
 133       (while (re-search-forward regexp nil t)
 134         (search-backward "\C-_")
 135         (setq type (if (eq ?F (char-after (1+ (point))))
 136                        1                ;function documentation
 137                      2)                 ;variable documentation
 138               symbol (progn
 139                        (forward-char 2)
 140                        (read doc-buffer))
 141               doc (buffer-substring
 142                    (point)
 143                    (progn
 144                      (if (search-forward "\C-_" nil 'move)
 145                          (1- (point))
 146                        (point))))
 147               item (assq symbol sym-list))
 148         (and (if (= type 1)
 149                  (and (fboundp symbol) (documentation symbol))
 150                (documentation-property symbol 'variable-documentation))
 151              (or item
 152                  (setq item (list symbol nil nil)
 153                        sym-list (cons item sym-list)))
 154              (setcar (nthcdr type item) doc))))
 155     sym-list))
 156
 157 ;; This is passed as the argument to map-atoms, so it is called once for every
 158 ;; symbol in obarray.  Takes one argument SYMBOL, and finds any memory-resident
 159 ;; documentation on that symbol if it matches a variable regexp.  WARNING: this
 160 ;; function depends on the symbols fn-doc var-doc regexp and item being bound
 161 ;; correctly when it is called!"
 162
 163 (defun super-apropos-accumulate (symbol)
 164   (cond ((string-match regexp (symbol-name symbol))
 165          (setq item (apropos-get-accum-item symbol))
 166          (setcar (cdr item) (or (safe-documentation symbol)
 167                                 (nth 1 item)))
 168          (setcar (nthcdr 2 item) (or (safe-documentation-property symbol)
 169                                      (nth 2 item))))
 170         (t
 171          (and (setq fn-doc (safe-documentation symbol))
 172               (string-match regexp fn-doc)
 173               (setcar (cdr (apropos-get-accum-item symbol)) fn-doc))
 174          (and (setq var-doc (safe-documentation-property symbol))
 175               (string-match regexp var-doc)
 176               (setcar (nthcdr 2 (apropos-get-accum-item symbol)) var-doc))))
 177   nil)
 178
 179 ;; Prints the symbols and documentation in alist MATCHES of form ((symbol
 180 ;; fn-doc var-doc) ...).  Uses optional argument REGEXP to speed up searching
 181 ;; for keybindings.  The names of all symbols in MATCHES must match REGEXP.
 182 ;; Displays in the buffer pointed to by standard-output.  Optional argument
 183 ;; SPACING means put blank lines in between each symbol's documentation.
 184 ;; Optional argument DO-ALL means do more time-consuming work, specifically,
 185 ;; consulting key bindings.  Should only be called within a
 186 ;; with-output-to-temp-buffer.
 187
 188 (defun apropos-print-matches (matches &optional regexp spacing do-all)
 189   (setq matches (sort matches (function
 190                                (lambda (a b)
 191                                  (string-lessp (car a) (car b))))))
 192   (let ((p matches)
 193         (old-buffer (current-buffer))
 194         item keys-done symbol tem)
 195     (save-excursion
 196       (set-buffer standard-output)
 197       (or matches (princ "No matches found."))
 198       (while (consp p)
 199         (setq item (car p)
 200               symbol (car item)
 201               p (cdr p))
 202         (or (not spacing) (bobp) (terpri))
 203         (princ symbol)                  ;print symbol name
 204         ;; don't calculate key-bindings unless needed
 205         (cond ((and do-all (commandp symbol) (not keys-done))
 206                (save-excursion
 207                  (set-buffer old-buffer)
 208                  (apropos-match-keys matches regexp))
 209                (setq keys-done t)))
 210         (cond ((and do-all
 211                     (or (setq tem (nthcdr 3 item))
 212                         (commandp symbol)))
 213                (indent-to 30 1)
 214                (if tem
 215                    (princ (mapconcat 'key-description tem ", "))
 216                  (princ "(not bound to any keys)"))))
 217         (terpri)
 218         (cond ((setq tem (nth 1 item))
 219                (princ "  Function: ")
 220                (princ (if do-all (substitute-command-keys tem) tem))))
 221         (or (bolp) (terpri))
 222         (cond ((setq tem (nth 2 item))
 223                (princ "  Variable: ")
 224                (princ (if do-all (substitute-command-keys tem) tem))))
 225         (or (bolp) (terpri)))))
 226   t)
 227
 228 ;; Find key bindings for symbols that are cars in ALIST.  Optionally, first
 229 ;; match the symbol name against REGEXP.  Modifies ALIST in place.  Each key
 230 ;; binding is added as a string to the end of the list in ALIST whose car is
 231 ;; the corresponding symbol.  The pointer to ALIST is returned.
 232
 233 (defun apropos-match-keys (alist &optional regexp)
 234   (let* ((current-local-map (current-local-map))
 235          (maps (append (and current-local-map
 236                             (accessible-keymaps current-local-map))
 237                        (accessible-keymaps (current-global-map))))
 238          map                            ;map we are now inspecting
 239          sequence                       ;key sequence to reach map
 240          i                              ;index into vector map
 241          command                        ;what is bound to current keys
 242          key                            ;last key to reach command
 243          local                          ;local binding for sequence + key
 244          item)                          ;symbol data item in alist
 245     ;; examine all reachable keymaps
 246     (while (consp maps)
 247       (setq map (cdr (car maps))
 248             sequence (car (car maps))   ;keys to reach this map
 249             maps (cdr maps))
 250       ;; Skip the leading `keymap', doc string, etc.
 251       (if (eq (car map) 'keymap)
 252           (setq map (cdr map)))
 253       (while (stringp (car-safe map))
 254         (setq map (cdr map)))
 255       (while (consp map)
 256         (cond ((consp (car map))
 257                (setq command (cdr (car map))
 258                      key (car (car map)))
 259                ;; Skip any menu prompt in this key binding.
 260                (and (consp command) (symbolp (cdr command))
 261                     (setq command (cdr command)))
 262                ;; if is a symbol, and matches optional regexp, and is a car
 263                ;; in alist, and is not shadowed by a different local binding,
 264                ;; record it
 265                (and (symbolp command)
 266                     (if regexp
 267                         (string-match regexp (symbol-name command))
 268                       t)
 269                     (setq item (assq command alist))
 270                     (if (or (vectorp sequence) (not (integerp key)))
 271                         (setq key (vconcat sequence (vector key)))
 272                       (setq key (concat sequence (char-to-string key))))
 273                     ;; checking if shadowed by local binding.
 274                     ;; either no local map, no local binding, or runs off the
 275                     ;; binding tree (number), or is the same binding
 276                     (or (not current-local-map)
 277                         (not (setq local (lookup-key current-local-map key)))
 278                         (numberp local)
 279                         (eq command local))
 280                     ;; check if this binding is already recorded
 281                     ;; (this can happen due to inherited keymaps)
 282                     (not (member key (nthcdr 3 item)))
 283                     ;; add this key binding to the item in alist
 284                     (nconc item (cons key nil))))
 285               ((vectorp (car map))
 286                (let ((i 0)
 287                      (vec (car map))
 288                      (len (length (car map))))
 289                  (while (< i len)
 290                    (setq command (aref vec i))
 291                    (setq key i)
 292                    ;; Skip any menu prompt in this key binding.
 293                    (and (consp command) (symbolp (cdr command))
 294                         (setq command (cdr command)))
 295                    ;; This is the same as the code in the previous case.
 296                    (and (symbolp command)
 297                         (if regexp
 298                             (string-match regexp (symbol-name command))
 299                           t)
 300                         (setq item (assq command alist))
 301                         (if (or (vectorp sequence) (not (integerp key)))
 302                             (setq key (vconcat sequence (vector key)))
 303                           (setq key (concat sequence (char-to-string key))))
 304                         ;; checking if shadowed by local binding.
 305                         ;; either no local map, no local binding, or runs off the
 306                         ;; binding tree (number), or is the same binding
 307                         (or (not current-local-map)
 308                             (not (setq local (lookup-key current-local-map key)))
 309                             (numberp local)
 310                             (eq command local))
 311                         ;; check if this binding is already recorded
 312                         ;; (this can happen due to inherited keymaps)
 313                         (not (member key (nthcdr 3 item)))
 314                         ;; add this key binding to the item in alist
 315                         (nconc item (cons key nil)))
 316                    (setq i (1+ i))))))
 317         (setq map (cdr map)))))
 318   alist)
 319
 320 ;; Get an alist item in alist apropos-accumulate whose car is SYMBOL.  Creates
 321 ;; the item if not already present.  Modifies apropos-accumulate in place.
 322
 323 (defun apropos-get-accum-item (symbol)
 324   (or (assq symbol apropos-accumulate)
 325       (progn
 326         (setq apropos-accumulate
 327               (cons (list symbol nil nil) apropos-accumulate))
 328         (assq symbol apropos-accumulate))))
 329
 330 (defun safe-documentation (function)
 331   "Like documentation, except it avoids calling `get_doc_string'.
 332 Will return nil instead."
 333   (while (symbolp function)
 334     (setq function (if (fboundp function)
 335                        (symbol-function function)
 336                      0)))
 337   (if (eq (car-safe function) 'macro)
 338       (setq function (cdr function)))
 339   (if (not (consp function))
 340       nil
 341     (if (not (memq (car function) '(lambda autoload)))
 342         nil
 343       (setq function (nth 2 function))
 344       (if (stringp function)
 345           function
 346         nil))))
 347
 348 (defun safe-documentation-property (symbol)
 349   "Like documentation-property, except it avoids calling `get_doc_string'.
 350 Will return nil instead."
 351   (setq symbol (get symbol 'variable-documentation))
 352   (if (numberp symbol)
 353       nil
 354     symbol))
 355
 356 ;;; apropos.el ends here