lisp/emacs-lisp/find-func.el

   1 ;;; find-func.el --- find the definition of the Emacs Lisp function near point
   2
   3 ;; Copyright (C) 1997, 1999, 2001 Free Software Foundation, Inc.
   4
   5 ;; Author: Jens Petersen <petersen@kurims.kyoto-u.ac.jp>
   6 ;; Maintainer: petersen@kurims.kyoto-u.ac.jp
   7 ;; Keywords: emacs-lisp, functions, variables
   8 ;; Created: 97/07/25
   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 2, or (at your option)
  15 ;; 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; see the file COPYING.  If not, write to the
  24 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  25 ;; Boston, MA 02111-1307, USA.
  26
  27 ;;; Commentary:
  28 ;;
  29 ;; The funniest thing about this is that I can't imagine why a package
  30 ;; so obviously useful as this hasn't been written before!!
  31 ;; ;;; find-func
  32 ;; (find-function-setup-keys)
  33 ;;
  34 ;; or just:
  35 ;;
  36 ;; (load "find-func")
  37 ;;
  38 ;; if you don't like the given keybindings and away you go!  It does
  39 ;; pretty much what you would expect, putting the cursor at the
  40 ;; definition of the function or variable at point.
  41 ;;
  42 ;; The code started out from `describe-function', `describe-key'
  43 ;; ("help.el") and `fff-find-loaded-emacs-lisp-function' (Noah Friedman's
  44 ;; "fff.el").
  45
  46 ;;; Code:
  47
  48 (require 'loadhist)
  49
  50 ;;; User variables:
  51
  52 (defgroup find-function nil
  53   "Finds the definition of the Emacs Lisp symbol near point."
  54 ;;   :prefix "find-function"
  55   :group 'lisp)
  56
  57 (defconst find-function-space-re "\\(?:\\s-\\|\n\\|;.*\n\\)+")
  58
  59 (defcustom find-function-regexp
  60   ;; Match things like (defun foo ...), (defmacro foo ...),
  61   ;; (define-skeleton foo ...), (define-generic-mode 'foo ...),
  62   ;;  (define-derived-mode foo ...), (define-minor-mode foo)
  63   (concat
  64    "^\\s-*(\\(def\\(ine-skeleton\\|ine-generic-mode\\|ine-derived-mode\\|\
  65 \[^cgv\W]\\w+\\*?\\)\\|define-minor-mode\
  66 \\|easy-mmode-define-global-mode\\)" find-function-space-re
  67    "\\('\\|\(quote \\)?%s\\(\\s-\\|$\\|\(\\|\)\\)")
  68   "The regexp used by `find-function' to search for a function definition.
  69 Note it must contain a `%s' at the place where `format'
  70 should insert the function name.  The default value avoids `defconst',
  71 `defgroup', `defvar'.
  72
  73 Please send improvements and fixes to the maintainer."
  74   :type 'regexp
  75   :group 'find-function
  76   :version "21.1")
  77
  78 (defcustom find-variable-regexp
  79   (concat"^\\s-*(def[^umag]\\(\\w\\|\\s_\\)+\\*?" find-function-space-re "%s\\(\\s-\\|$\\)")
  80   "The regexp used by `find-variable' to search for a variable definition.
  81 It should match right up to the variable name.  The default value
  82 avoids `defun', `defmacro', `defalias', `defadvice', `defgroup'.
  83
  84 Please send improvements and fixes to the maintainer."
  85   :type 'regexp
  86   :group 'find-function
  87   :version "21.1")
  88
  89 (defcustom find-function-source-path nil
  90   "The default list of directories where `find-function' searches.
  91
  92 If this variable is nil then `find-function' searches `load-path' by
  93 default."
  94   :type '(repeat directory)
  95   :group 'find-function)
  96
  97 (defcustom find-function-recenter-line 1
  98   "The window line-number from which to start displaying a symbol definition.
  99 A value of nil implies center the beginning of the definition.
 100 See `find-function' and `find-variable'."
 101   :type '(choice (const :tag "Center" nil)
 102                  integer)
 103   :group 'find-function
 104   :version "20.3")
 105
 106 (defcustom find-function-after-hook nil
 107   "Hook run after finding symbol definition.
 108
 109 See the functions `find-function' and `find-variable'."
 110   :group 'find-function
 111   :version "20.3")
 112
 113 ;;; Functions:
 114
 115 (defun find-library-suffixes ()
 116   (let ((suffixes nil))
 117     (dolist (suffix load-suffixes (nreverse suffixes))
 118       (unless (string-match "elc" suffix) (push suffix suffixes)))))
 119
 120 (defun find-library-name (library)
 121   "Return the full name of the elisp source of LIBRARY."
 122   ;; If the library is byte-compiled, try to find a source library by
 123   ;; the same name.
 124   (if (string-match "\\.el\\(c\\(\\..*\\)?\\)\\'" library)
 125       (setq library (replace-match "" t t library)))
 126   (or (locate-file library
 127                    (or find-function-source-path load-path)
 128                    (append (find-library-suffixes) '("")))
 129       (error "Can't find library %s" library)))
 130
 131 ;;;###autoload
 132 (defun find-library (library)
 133   "Find the elisp source of LIBRARY."
 134   (interactive
 135    (list
 136     (completing-read "Library name: "
 137                      'locate-file-completion
 138                      (cons (or find-function-source-path load-path)
 139                            (find-library-suffixes)))))
 140   (let ((buf (find-file-noselect (find-library-name library))))
 141     (condition-case nil (switch-to-buffer buf) (error (pop-to-buffer buf)))))
 142
 143 ;;;###autoload
 144 (defun find-function-search-for-symbol (symbol variable-p library)
 145   "Search for SYMBOL.
 146 If VARIABLE-P is nil, `find-function-regexp' is used, otherwise
 147 `find-variable-regexp' is used.  The search is done in library LIBRARY."
 148   (if (null library)
 149       (error "Don't know where `%s' is defined" symbol))
 150   ;; Some functions are defined as part of the construct
 151   ;; that defines something else.
 152   (while (get symbol 'definition-name)
 153     (setq symbol (get symbol 'definition-name)))
 154   (save-match-data
 155     (if (string-match "\\.el\\(c\\)\\'" library)
 156         (setq library (substring library 0 (match-beginning 1))))
 157     (let* ((filename (find-library-name library)))
 158       (with-current-buffer (find-file-noselect filename)
 159         (let ((regexp (format (if variable-p
 160                                   find-variable-regexp
 161                                 find-function-regexp)
 162                               (regexp-quote (symbol-name symbol))))
 163               (case-fold-search))
 164           (with-syntax-table emacs-lisp-mode-syntax-table
 165             (goto-char (point-min))
 166             (if (or (re-search-forward regexp nil t)
 167                     (re-search-forward
 168                      (concat "^([^ ]+" find-function-space-re "['(]"
 169                              (regexp-quote (symbol-name symbol))
 170                              "\\>")
 171                      nil t))
 172                 (progn
 173                   (beginning-of-line)
 174                   (cons (current-buffer) (point)))
 175               (error "Cannot find definition of `%s' in library `%s'"
 176                      symbol library))))))))
 177
 178 ;;;###autoload
 179 (defun find-function-noselect (function)
 180   "Return a pair (BUFFER . POINT) pointing to the definition of FUNCTION.
 181
 182 Finds the Emacs Lisp library containing the definition of FUNCTION
 183 in a buffer and the point of the definition.  The buffer is
 184 not selected.
 185
 186 If the file where FUNCTION is defined is not known, then it is
 187 searched for in `find-function-source-path' if non nil, otherwise
 188 in `load-path'."
 189   (if (not function)
 190       (error "You didn't specify a function"))
 191   (and (subrp (symbol-function function))
 192        (error "%s is a primitive function" function))
 193   (let ((def (symbol-function function))
 194         aliases)
 195     (while (symbolp def)
 196       (or (eq def function)
 197           (if aliases
 198               (setq aliases (concat aliases
 199                                     (format ", which is an alias for `%s'"
 200                                             (symbol-name def))))
 201             (setq aliases (format "`%s' an alias for `%s'"
 202                                   function (symbol-name def)))))
 203       (setq function (symbol-function function)
 204             def (symbol-function function)))
 205     (if aliases
 206         (message aliases))
 207     (let ((library
 208            (cond ((eq (car-safe def) 'autoload)
 209                   (nth 1 def))
 210                  ((symbol-file function)))))
 211       (find-function-search-for-symbol function nil library))))
 212
 213 (defalias 'function-at-point 'function-called-at-point)
 214
 215 (defun find-function-read (&optional variable-p)
 216   "Read and return an interned symbol, defaulting to the one near point.
 217
 218 If the optional VARIABLE-P is nil, then a function is gotten
 219 defaulting to the value of the function `function-at-point', otherwise
 220 a variable is asked for, with the default coming from
 221 `variable-at-point'."
 222   (let ((symb (funcall (if variable-p
 223                            'variable-at-point
 224                          'function-at-point)))
 225         (enable-recursive-minibuffers t)
 226         val)
 227     (if (equal symb 0)
 228         (setq symb nil))
 229     (setq val (if variable-p
 230                   (completing-read
 231                    (concat "Find variable"
 232                            (if symb
 233                                (format " (default %s)" symb))
 234                            ": ")
 235                    obarray 'boundp t nil)
 236                 (completing-read
 237                  (concat "Find function"
 238                          (if symb
 239                              (format " (default %s)" symb))
 240                          ": ")
 241                  obarray 'fboundp t nil)))
 242     (list (if (equal val "")
 243               symb
 244             (intern val)))))
 245
 246 (defun find-function-do-it (symbol variable-p switch-fn)
 247   "Find Emacs Lisp SYMBOL in a buffer and display it.
 248 If VARIABLE-P is nil, a function definition is searched for, otherwise
 249 a variable definition is searched for.  The start of a definition is
 250 centered according to the variable `find-function-recenter-line'.
 251 See also `find-function-after-hook'  It is displayed with function SWITCH-FN.
 252
 253 Point is saved in the buffer if it is one of the current buffers."
 254   (let* ((orig-point (point))
 255         (orig-buf (window-buffer))
 256         (orig-buffers (buffer-list))
 257         (buffer-point (save-excursion
 258                         (funcall (if variable-p
 259                                       'find-variable-noselect
 260                                     'find-function-noselect)
 261                                   symbol)))
 262         (new-buf (car buffer-point))
 263         (new-point (cdr buffer-point)))
 264     (when buffer-point
 265       (when (memq new-buf orig-buffers)
 266         (push-mark orig-point))
 267       (funcall switch-fn new-buf)
 268       (goto-char new-point)
 269       (recenter find-function-recenter-line)
 270       (run-hooks 'find-function-after-hook))))
 271
 272 ;;;###autoload
 273 (defun find-function (function)
 274   "Find the definition of the FUNCTION near point.
 275
 276 Finds the Emacs Lisp library containing the definition of the function
 277 near point (selected by `function-at-point') in a buffer and
 278 places point before the definition.  Point is saved in the buffer if
 279 it is one of the current buffers.
 280
 281 The library where FUNCTION is defined is searched for in
 282 `find-function-source-path', if non nil, otherwise in `load-path'.
 283 See also `find-function-recenter-line' and `find-function-after-hook'."
 284   (interactive (find-function-read))
 285   (find-function-do-it function nil 'switch-to-buffer))
 286
 287 ;;;###autoload
 288 (defun find-function-other-window (function)
 289   "Find, in another window, the definition of FUNCTION near point.
 290
 291 See `find-function' for more details."
 292   (interactive (find-function-read))
 293   (find-function-do-it function nil 'switch-to-buffer-other-window))
 294
 295 ;;;###autoload
 296 (defun find-function-other-frame (function)
 297   "Find, in ananother frame, the definition of FUNCTION near point.
 298
 299 See `find-function' for more details."
 300   (interactive (find-function-read))
 301   (find-function-do-it function nil 'switch-to-buffer-other-frame))
 302
 303 ;;;###autoload
 304 (defun find-variable-noselect (variable &optional file)
 305   "Return a pair `(BUFFER . POINT)' pointing to the definition of SYMBOL.
 306
 307 Finds the Emacs Lisp library containing the definition of SYMBOL
 308 in a buffer and the point of the definition.  The buffer is
 309 not selected.
 310
 311 The library where VARIABLE is defined is searched for in FILE or
 312 `find-function-source-path', if non nil, otherwise in `load-path'."
 313   (if (not variable)
 314       (error "You didn't specify a variable"))
 315   ;; Fixme: I think `symbol-file' should be fixed instead.  -- fx
 316   (let ((library (or file (symbol-file (cons 'defvar variable)))))
 317     (find-function-search-for-symbol variable 'variable library)))
 318
 319 ;;;###autoload
 320 (defun find-variable (variable)
 321   "Find the definition of the VARIABLE near point.
 322
 323 Finds the Emacs Lisp library containing the definition of the variable
 324 near point (selected by `variable-at-point') in a buffer and
 325 places point before the definition.  Point is saved in the buffer if
 326 it is one of the current buffers.
 327
 328 The library where VARIABLE is defined is searched for in
 329 `find-function-source-path', if non nil, otherwise in `load-path'.
 330 See also `find-function-recenter-line' and `find-function-after-hook'."
 331   (interactive (find-function-read 'variable))
 332   (find-function-do-it variable t 'switch-to-buffer))
 333
 334 ;;;###autoload
 335 (defun find-variable-other-window (variable)
 336   "Find, in another window, the definition of VARIABLE near point.
 337
 338 See `find-variable' for more details."
 339   (interactive (find-function-read 'variable))
 340   (find-function-do-it variable t 'switch-to-buffer-other-window))
 341
 342 ;;;###autoload
 343 (defun find-variable-other-frame (variable)
 344   "Find, in annother frame, the definition of VARIABLE near point.
 345
 346 See `find-variable' for more details."
 347   (interactive (find-function-read 'variable))
 348   (find-function-do-it variable t 'switch-to-buffer-other-frame))
 349
 350 ;;;###autoload
 351 (defun find-function-on-key (key)
 352   "Find the function that KEY invokes.  KEY is a string.
 353 Point is saved if FUNCTION is in the current buffer."
 354   (interactive "kFind function on key: ")
 355   (let (defn)
 356     (save-excursion
 357       (let* ((event (and (eventp key) (aref key 0))) ; Null event OK below.
 358              (start (event-start event))
 359              (modifiers (event-modifiers event))
 360              (window (and (or (memq 'click modifiers) (memq 'down modifiers)
 361                               (memq 'drag modifiers))
 362                           (posn-window start))))
 363         ;; For a mouse button event, go to the button it applies to
 364         ;; to get the right key bindings.  And go to the right place
 365         ;; in case the keymap depends on where you clicked.
 366         (when (windowp window)
 367           (set-buffer (window-buffer window))
 368           (goto-char (posn-point start)))
 369         (setq defn (key-binding key))))
 370     (let ((key-desc (key-description key)))
 371       (if (or (null defn) (integerp defn))
 372           (message "%s is unbound" key-desc)
 373         (if (consp defn)
 374             (message "%s runs %s" key-desc (prin1-to-string defn))
 375           (find-function-other-window defn))))))
 376
 377 ;;;###autoload
 378 (defun find-function-at-point ()
 379   "Find directly the function at point in the other window."
 380   (interactive)
 381   (let ((symb (function-at-point)))
 382     (when symb
 383       (find-function-other-window symb))))
 384
 385 ;;;###autoload
 386 (defun find-variable-at-point ()
 387   "Find directly the function at point in the other window."
 388   (interactive)
 389   (let ((symb (variable-at-point)))
 390     (when (and symb (not (equal symb 0)))
 391       (find-variable-other-window symb))))
 392
 393 ;;;###autoload
 394 (defun find-function-setup-keys ()
 395   "Define some key bindings for the find-function family of functions."
 396   (define-key ctl-x-map "F" 'find-function)
 397   (define-key ctl-x-4-map "F" 'find-function-other-window)
 398   (define-key ctl-x-5-map "F" 'find-function-other-frame)
 399   (define-key ctl-x-map "K" 'find-function-on-key)
 400   (define-key ctl-x-map "V" 'find-variable)
 401   (define-key ctl-x-4-map "V" 'find-variable-other-window)
 402   (define-key ctl-x-5-map "V" 'find-variable-other-frame))
 403
 404 (provide 'find-func)
 405
 406 ;;; find-func.el ends here