lisp/finder.el

   1 ;;; finder.el --- topic & keyword-based code finder
   2
   3 ;; Copyright (C) 1992, 1997-1999, 2001-2017 Free Software Foundation,
   4 ;; Inc.
   5
   6 ;; Author: Eric S. Raymond <esr@snark.thyrsus.com>
   7 ;; Created: 16 Jun 1992
   8 ;; Version: 1.0
   9 ;; Keywords: help
  10
  11 ;; This file is part of GNU Emacs.
  12
  13 ;; GNU Emacs is free software: you can redistribute it and/or modify
  14 ;; it under the terms of the GNU General Public License as published by
  15 ;; the Free Software Foundation, either version 3 of the License, or
  16 ;; (at your option) any later version.
  17
  18 ;; GNU Emacs is distributed in the hope that it will be useful,
  19 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  20 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21 ;; GNU General Public License for more details.
  22
  23 ;; You should have received a copy of the GNU General Public License
  24 ;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
  25
  26 ;;; Commentary:
  27
  28 ;; This mode uses the Keywords library header to provide code-finding
  29 ;; services by keyword.
  30
  31 ;;; Code:
  32
  33 (require 'package)
  34 (require 'lisp-mnt)
  35 (require 'find-func) ;for find-library(-suffixes)
  36 (require 'finder-inf nil t)
  37
  38 ;; These are supposed to correspond to top-level customization groups,
  39 ;; says rms.
  40 (defvar finder-known-keywords
  41   '((abbrev     . "abbreviation handling, typing shortcuts, and macros")
  42     (bib        . "bibliography processors")
  43     (c          . "C and related programming languages")
  44     (calendar   . "calendar and time management tools")
  45     (comm       . "communications, networking, and remote file access")
  46     (convenience . "convenience features for faster editing")
  47     (data       . "editing data (non-text) files")
  48     (docs       . "Emacs documentation facilities")
  49     (emulations . "emulations of other editors")
  50     (extensions . "Emacs Lisp language extensions")
  51     (faces      . "fonts and colors for text")
  52     (files      . "file editing and manipulation")
  53     (frames     . "Emacs frames and window systems")
  54     (games      . "games, jokes and amusements")
  55     (hardware   . "interfacing with system hardware")
  56     (help       . "Emacs help systems")
  57     (hypermedia . "links between text or other media types")
  58     (i18n       . "internationalization and character-set support")
  59     (internal   . "code for Emacs internals, build process, defaults")
  60     (languages  . "specialized modes for editing programming languages")
  61     (lisp       . "Lisp support, including Emacs Lisp")
  62     (local      . "code local to your site")
  63     (maint      . "Emacs development tools and aids")
  64     (mail       . "email reading and posting")
  65     (matching   . "searching, matching, and sorting")
  66     (mouse      . "mouse support")
  67     (multimedia . "images and sound")
  68     (news       . "USENET news reading and posting")
  69     (outlines   . "hierarchical outlining and note taking")
  70     (processes  . "processes, subshells, and compilation")
  71     (terminals  . "text terminals (ttys)")
  72     (tex        . "the TeX document formatter")
  73     (tools      . "programming tools")
  74     (unix       . "UNIX feature interfaces and emulators")
  75     (vc         . "version control")
  76     (wp         . "word processing"))
  77   "Association list of the standard \"Keywords:\" headers.
  78 Each element has the form (KEYWORD . DESCRIPTION).")
  79
  80 (defvar finder-mode-map
  81   (let ((map (make-sparse-keymap))
  82         (menu-map (make-sparse-keymap "Finder")))
  83     (define-key map " " 'finder-select)
  84     (define-key map "f" 'finder-select)
  85     (define-key map [follow-link] 'mouse-face)
  86     (define-key map [mouse-2]   'finder-mouse-select)
  87     (define-key map "\C-m"      'finder-select)
  88     (define-key map "?" 'finder-summary)
  89     (define-key map "n" 'next-line)
  90     (define-key map "p" 'previous-line)
  91     (define-key map "q" 'finder-exit)
  92     (define-key map "d" 'finder-list-keywords)
  93
  94     (define-key map [menu-bar finder-mode]
  95       (cons "Finder" menu-map))
  96     (define-key menu-map [finder-exit]
  97       '(menu-item "Quit" finder-exit
  98                   :help "Exit Finder mode"))
  99     (define-key menu-map [finder-summary]
 100       '(menu-item "Summary" finder-summary
 101                   :help "Summary item on current line in a finder buffer"))
 102     (define-key menu-map [finder-list-keywords]
 103       '(menu-item "List keywords" finder-list-keywords
 104                   :help "Display descriptions of the keywords in the Finder buffer"))
 105     (define-key menu-map [finder-select]
 106       '(menu-item "Select" finder-select
 107                   :help "Select item on current line in a finder buffer"))
 108     map)
 109   "Keymap used in `finder-mode'.")
 110
 111 (defvar finder-mode-syntax-table
 112   (let ((st (make-syntax-table emacs-lisp-mode-syntax-table)))
 113     (modify-syntax-entry ?\; ".   " st)
 114     st)
 115   "Syntax table used while in `finder-mode'.")
 116
 117 (defvar finder-headmark nil
 118   "Internal Finder mode variable, local in Finder buffer.")
 119
 120 ;;; Code for regenerating the keyword list.
 121
 122 (defvar finder-keywords-hash nil
 123   "Hash table mapping keywords to lists of package names.
 124 Keywords and package names both should be symbols.")
 125
 126 (defvar generated-finder-keywords-file "finder-inf.el"
 127   "The function `finder-compile-keywords' writes keywords into this file.")
 128
 129 ;; Skip autogenerated files, because they will never contain anything
 130 ;; useful, and because in parallel builds of Emacs they may get
 131 ;; modified while we are trying to read them.
 132 ;; https://lists.gnu.org/r/emacs-pretest-bug/2007-01/msg00469.html
 133 ;; ldefs-boot is not auto-generated, but has nothing useful.
 134 (defvar finder-no-scan-regexp "\\(^\\.#\\|\\(loaddefs\\|ldefs-boot\\|\
 135 cus-load\\|finder-inf\\|esh-groups\\|subdirs\\|leim-list\\)\\.el$\\)"
 136   "Regexp matching file names not to scan for keywords.")
 137
 138 (autoload 'autoload-rubric "autoload")
 139
 140 (defconst finder--builtins-descriptions
 141   ;; I have no idea whether these are supposed to be capitalized
 142   ;; and/or end in a full-stop.  Existing file headers are inconsistent,
 143   ;; but mainly seem to not do so.
 144   '((emacs . "the extensible text editor")
 145     (nxml . "a new XML mode"))
 146   "Alist of built-in package descriptions.
 147 Entries have the form (PACKAGE-SYMBOL . DESCRIPTION).
 148 When generating `package--builtins', this overrides what the description
 149 would otherwise be.")
 150
 151 (defvar finder--builtins-alist
 152   '(("calc" . calc)
 153     ("ede"  . ede)
 154     ("erc"  . erc)
 155     ("eshell" . eshell)
 156     ("gnus" . gnus)
 157     ("international" . emacs)
 158     ("language" . emacs)
 159     ("mh-e" . mh-e)
 160     ("semantic" . semantic)
 161     ("analyze" . semantic)
 162     ("bovine" . semantic)
 163     ("decorate" . semantic)
 164     ("symref" . semantic)
 165     ("wisent" . semantic)
 166     ;; This should really be ("nxml" . nxml-mode), because nxml-mode.el
 167     ;; is the main file for the package.  Then we would not need an
 168     ;; entry in finder--builtins-descriptions.  But I do not know if
 169     ;; it is safe to change this, in case it is already in use.
 170     ("nxml" . nxml)
 171     ("org"  . org)
 172     ("srecode" . srecode)
 173     ("term" . emacs)
 174     ("url"  . url))
 175   "Alist of built-in package directories.
 176 Each element should have the form (DIR . PACKAGE), where DIR is a
 177 directory name and PACKAGE is the name of a package (a symbol).
 178 When generating `package--builtins', Emacs assumes any file in
 179 DIR is part of the package PACKAGE.")
 180
 181 (defun finder-compile-keywords (&rest dirs)
 182   "Regenerate list of built-in Emacs packages.
 183 This recomputes `package--builtins' and `finder-keywords-hash',
 184 and prints them into the file `generated-finder-keywords-file'.
 185
 186 Optional DIRS is a list of Emacs Lisp directories to compile
 187 from; the default is `load-path'."
 188   ;; Allow compressed files also.
 189   (setq package--builtins nil)
 190   (setq finder-keywords-hash (make-hash-table :test 'eq))
 191   (let ((el-file-regexp "^\\([^=].*\\)\\.el\\(\\.\\(gz\\|Z\\)\\)?$")
 192         package-override files base-name ; processed
 193         summary keywords package version entry desc)
 194     (dolist (d (or dirs load-path))
 195       (when (file-exists-p (directory-file-name d))
 196         (message "Scanning %s for finder" d)
 197         (setq package-override
 198               (intern-soft
 199                (cdr-safe
 200                 (assoc (file-name-nondirectory (directory-file-name d))
 201                        finder--builtins-alist))))
 202         (setq files (directory-files d nil el-file-regexp))
 203         (dolist (f files)
 204           (unless (or (string-match finder-no-scan-regexp f)
 205                       (null (setq base-name
 206                                   (and (string-match el-file-regexp f)
 207                                        (intern (match-string 1 f))))))
 208 ;;                    (memq base-name processed))
 209 ;; There are multiple files in the tree with the same basename.
 210 ;; So skipping files based on basename means you randomly (depending
 211 ;; on which order the files are traversed in) miss some packages.
 212 ;; https://debbugs.gnu.org/14010
 213 ;; You might think this could lead to two files providing the same package,
 214 ;; but it does not, because the duplicates are (at time of writing)
 215 ;; all due to files in cedet, which end up with package-override set.
 216 ;; FIXME this is obviously fragile.
 217 ;; Make the (eq base-name package) case below issue a warning if
 218 ;; package-override is nil?
 219 ;;          (push base-name processed)
 220             (with-temp-buffer
 221               (insert-file-contents (expand-file-name f d))
 222               (setq keywords (mapcar 'intern (lm-keywords-list))
 223                     package  (or package-override
 224                                  (let ((str (lm-header "package")))
 225                                    (if str (intern str)))
 226                                  base-name)
 227                     summary  (or (cdr
 228                                   (assq package finder--builtins-descriptions))
 229                                  (lm-synopsis))
 230                     version  (lm-header "version")))
 231             (when summary
 232               (setq version (ignore-errors (version-to-list version)))
 233               (setq entry (assq package package--builtins))
 234               (cond ((null entry)
 235                      (push (cons package
 236                                  (package-make-builtin version summary))
 237                            package--builtins))
 238                     ;; The idea here is that eg calc.el gets to define
 239                     ;; the description of the calc package.
 240                     ;; This does not work for eg nxml-mode.el.
 241                     ((or (eq base-name package) version)
 242                      (setq desc (cdr entry))
 243                      (aset desc 0 version)
 244                      (aset desc 2 summary)))
 245               (dolist (kw keywords)
 246                 (puthash kw
 247                          (cons package
 248                                (delq package
 249                                      (gethash kw finder-keywords-hash)))
 250                          finder-keywords-hash))))))))
 251
 252   (setq package--builtins
 253         (sort package--builtins
 254               (lambda (a b) (string< (symbol-name (car a))
 255                                      (symbol-name (car b))))))
 256
 257   (with-current-buffer
 258       (find-file-noselect generated-finder-keywords-file)
 259     (setq buffer-undo-list t)
 260     (erase-buffer)
 261     (insert (autoload-rubric generated-finder-keywords-file
 262                              "keyword-to-package mapping" t))
 263     (search-backward "\f")
 264     ;; FIXME: Now that we have package--builtin-versions, package--builtins is
 265     ;; only needed to get the list of unversioned packages and to get the
 266     ;; summary description of each package.
 267     (insert "(setq package--builtins '(\n")
 268     (dolist (package package--builtins)
 269       (insert "  ")
 270       (prin1 package (current-buffer))
 271       (insert "\n"))
 272     (insert "))\n\n")
 273     ;; Insert hash table.
 274     (insert "(setq finder-keywords-hash\n      ")
 275     (prin1 finder-keywords-hash (current-buffer))
 276     (insert ")\n")
 277     (basic-save-buffer)))
 278
 279 (defun finder-compile-keywords-make-dist ()
 280   "Regenerate `finder-inf.el' for the Emacs distribution."
 281   (apply 'finder-compile-keywords command-line-args-left)
 282   (kill-emacs))
 283
 284 ;;; Now the retrieval code
 285
 286 (defun finder-insert-at-column (column &rest strings)
 287   "Insert, at column COLUMN, other args STRINGS."
 288   (if (>= (current-column) column) (insert "\n"))
 289   (move-to-column column t)
 290   (apply 'insert strings))
 291
 292 (defvar finder-help-echo nil)
 293
 294 (defun finder-mouse-face-on-line ()
 295   "Put `mouse-face' and `help-echo' properties on the previous line."
 296   (save-excursion
 297     (forward-line -1)
 298     ;; If finder-insert-at-column moved us to a new line, go back one more.
 299     (if (looking-at "[ \t]") (forward-line -1))
 300     (unless finder-help-echo
 301       (setq finder-help-echo
 302             (let* ((keys1 (where-is-internal 'finder-select
 303                                              finder-mode-map))
 304                    (keys (nconc (where-is-internal
 305                                  'finder-mouse-select finder-mode-map)
 306                                 keys1)))
 307               (concat (mapconcat 'key-description keys ", ")
 308                       ": select item"))))
 309     (add-text-properties
 310      (line-beginning-position) (line-end-position)
 311      '(mouse-face highlight
 312                   help-echo finder-help-echo))))
 313
 314 (defun finder-unknown-keywords ()
 315   "Return an alist of unknown keywords and number of their occurrences.
 316 Unknown keywords are those present in `finder-keywords-hash' but
 317 not `finder-known-keywords'."
 318   (let (alist)
 319     (maphash (lambda (kw packages)
 320                (unless (assq kw finder-known-keywords)
 321                  (push (cons kw (length packages)) alist)))
 322              finder-keywords-hash)
 323     (sort alist (lambda (a b) (string< (car a) (car b))))))
 324
 325 ;;;###autoload
 326 (defun finder-list-keywords ()
 327   "Display descriptions of the keywords in the Finder buffer."
 328   (interactive)
 329   (if (get-buffer "*Finder*")
 330       (pop-to-buffer "*Finder*")
 331     (pop-to-buffer (get-buffer-create "*Finder*"))
 332     (finder-mode)
 333     (let ((inhibit-read-only t))
 334       (erase-buffer)
 335       (dolist (assoc finder-known-keywords)
 336         (let ((keyword (car assoc)))
 337           (insert (propertize (symbol-name keyword)
 338                               'font-lock-face 'font-lock-constant-face))
 339           (finder-insert-at-column 14 (concat (cdr assoc) "\n"))
 340           (finder-mouse-face-on-line)))
 341       (goto-char (point-min))
 342       (setq finder-headmark (point)
 343             buffer-read-only t)
 344       (set-buffer-modified-p nil)
 345       (balance-windows)
 346       (finder-summary))))
 347
 348 (defun finder-list-matches (key)
 349   (let* ((id (intern key))
 350          (packages (gethash id finder-keywords-hash)))
 351     (unless packages
 352       (error "No packages matching key `%s'" key))
 353     (let ((package-list-unversioned t))
 354       (package-show-package-list packages))))
 355
 356 (define-button-type 'finder-xref 'action #'finder-goto-xref)
 357
 358 (defun finder-goto-xref (button)
 359   "Jump to a lisp file for the BUTTON at point."
 360   (let* ((file (button-get button 'xref))
 361          (lib (locate-library file)))
 362     (if lib (finder-commentary lib)
 363       (message "Unable to locate `%s'" file))))
 364
 365 ;;;###autoload
 366 (defun finder-commentary (file)
 367   "Display FILE's commentary section.
 368 FILE should be in a form suitable for passing to `locate-library'."
 369   (interactive
 370    (list
 371     (completing-read "Library name: "
 372                      (apply-partially 'locate-file-completion-table
 373                                       (or find-function-source-path load-path)
 374                                       (find-library-suffixes)))))
 375   (let ((str (lm-commentary (find-library-name file))))
 376     (or str (error "Can't find any Commentary section"))
 377     ;; This used to use *Finder* but that would clobber the
 378     ;; directory of categories.
 379     (pop-to-buffer "*Finder-package*")
 380     (setq buffer-read-only nil
 381           buffer-undo-list t)
 382     (erase-buffer)
 383     (insert str)
 384     (goto-char (point-min))
 385     (delete-blank-lines)
 386     (goto-char (point-max))
 387     (delete-blank-lines)
 388     (goto-char (point-min))
 389     (while (re-search-forward "^;+ ?" nil t)
 390       (replace-match "" nil nil))
 391     (goto-char (point-min))
 392     (while (re-search-forward "\\<\\([-[:alnum:]]+\\.el\\)\\>" nil t)
 393       (if (locate-library (match-string 1))
 394           (make-text-button (match-beginning 1) (match-end 1)
 395                             'xref (match-string-no-properties 1)
 396                             'help-echo "Read this file's commentary"
 397                             :type 'finder-xref)))
 398     (goto-char (point-min))
 399     (setq buffer-read-only t)
 400     (set-buffer-modified-p nil)
 401     (shrink-window-if-larger-than-buffer)
 402     (finder-mode)
 403     (finder-summary)))
 404
 405 (defun finder-current-item ()
 406   (let ((key (save-excursion
 407                (beginning-of-line)
 408                (current-word))))
 409     (if (or (and finder-headmark (< (point) finder-headmark))
 410             (zerop (length key)))
 411         (error "No keyword or filename on this line")
 412       key)))
 413
 414 (defun finder-select ()
 415   "Select item on current line in a Finder buffer."
 416   (interactive)
 417   (let ((key (finder-current-item)))
 418       (if (string-match "\\.el$" key)
 419           (finder-commentary key)
 420         (finder-list-matches key))))
 421
 422 (defun finder-mouse-select (event)
 423   "Select item in a Finder buffer with the mouse."
 424   (interactive "e")
 425   (with-current-buffer (window-buffer (posn-window (event-start event)))
 426     (goto-char (posn-point (event-start event)))
 427     (finder-select)))
 428
 429 ;;;###autoload
 430 (defun finder-by-keyword ()
 431   "Find packages matching a given keyword."
 432   (interactive)
 433   (finder-list-keywords))
 434
 435 (define-derived-mode finder-mode nil "Finder"
 436   "Major mode for browsing package documentation.
 437 \\<finder-mode-map>
 438 \\[finder-select]       more help for the item on the current line
 439 \\[finder-exit] exit Finder mode and kill the Finder buffer."
 440   :syntax-table finder-mode-syntax-table
 441   (setq buffer-read-only t
 442         buffer-undo-list t)
 443   (set (make-local-variable 'finder-headmark) nil))
 444
 445 (defun finder-summary ()
 446   "Summarize basic Finder commands."
 447   (interactive)
 448   (message "%s"
 449    (substitute-command-keys
 450     "\\<finder-mode-map>\\[finder-select] = select, \
 451 \\[finder-mouse-select] = select, \\[finder-list-keywords] = to \
 452 finder directory, \\[finder-exit] = quit, \\[finder-summary] = help")))
 453
 454 (defun finder-exit ()
 455   "Exit Finder mode.
 456 Delete the window and kill all Finder-related buffers."
 457   (interactive)
 458   (ignore-errors (delete-window))
 459   (let ((buf "*Finder*"))
 460     (and (get-buffer buf) (kill-buffer buf))))
 461
 462 (defun finder-unload-function ()
 463   "Unload the Finder library."
 464   (with-demoted-errors (unload-feature 'finder-inf t))
 465   ;; continue standard unloading
 466   nil)
 467
 468 \f
 469 (provide 'finder)
 470
 471 ;;; finder.el ends here