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1b09702a NF |
1 | ;;; eldoc.el --- show function arglist or variable docstring in echo area |
2 | ||
332ae8db | 3 | ;; Copyright (C) 1996, 1997 Free Software Foundation, Inc. |
1b09702a NF |
4 | |
5 | ;; Author: Noah Friedman <friedman@prep.ai.mit.edu> | |
6 | ;; Maintainer: friedman@prep.ai.mit.edu | |
7 | ;; Keywords: extensions | |
1b09702a NF |
8 | ;; Created: 1995-10-06 |
9 | ||
332ae8db | 10 | ;; $Id: eldoc.el,v 1.7 1996/10/04 04:43:42 friedman Exp $ |
1b09702a | 11 | |
332ae8db | 12 | ;; This file is part of GNU Emacs. |
1b09702a | 13 | |
332ae8db | 14 | ;; GNU Emacs is free software; you can redistribute it and/or modify |
1b09702a NF |
15 | ;; it under the terms of the GNU General Public License as published by |
16 | ;; the Free Software Foundation; either version 2, or (at your option) | |
17 | ;; any later version. | |
332ae8db NF |
18 | |
19 | ;; GNU Emacs is distributed in the hope that it will be useful, | |
1b09702a NF |
20 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of |
21 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
22 | ;; GNU General Public License for more details. | |
332ae8db | 23 | |
1b09702a | 24 | ;; You should have received a copy of the GNU General Public License |
332ae8db NF |
25 | ;; along with GNU Emacs; see the file COPYING. If not, write to the |
26 | ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
27 | ;; Boston, MA 02111-1307, USA. | |
1b09702a NF |
28 | |
29 | ;;; Commentary: | |
30 | ||
332ae8db NF |
31 | ;; This program was inspired by the behavior of the "mouse documentation |
32 | ;; window" on many Lisp Machine systems; as you type a function's symbol | |
33 | ;; name as part of a sexp, it will print the argument list for that | |
34 | ;; function. Behavior is not identical; for example, you need not actually | |
35 | ;; type the function name, you need only move point around in a sexp that | |
36 | ;; calls it. Also, if point is over a documented variable, it will print | |
37 | ;; the one-line documentation for that variable instead, to remind you of | |
38 | ;; that variable's meaning. | |
1b09702a NF |
39 | |
40 | ;; One useful way to enable this minor mode is to put the following in your | |
41 | ;; .emacs: | |
42 | ;; | |
43 | ;; (autoload 'turn-on-eldoc-mode "eldoc" nil t) | |
44 | ;; (add-hook 'emacs-lisp-mode-hook 'turn-on-eldoc-mode) | |
45 | ;; (add-hook 'lisp-interaction-mode-hook 'turn-on-eldoc-mode) | |
46 | ||
47 | ;;; Code: | |
48 | ||
332ae8db NF |
49 | ;; Use idle timers if available in the version of emacs running. |
50 | ;; Please don't change this to use `require'; this package works as-is in | |
51 | ;; XEmacs (which doesn't have timer.el as of 19.14), and I would like to | |
52 | ;; maintain compatibility with that since I must use it sometimes. --Noah | |
53 | (or (featurep 'timer) | |
54 | (load "timer" t)) | |
55 | ||
1b09702a NF |
56 | ;;;###autoload |
57 | (defvar eldoc-mode nil | |
58 | "*If non-nil, show the defined parameters for the elisp function near point. | |
59 | ||
60 | For the emacs lisp function at the beginning of the sexp which point is | |
61 | within, show the defined parameters for the function in the echo area. | |
62 | This information is extracted directly from the function or macro if it is | |
332ae8db NF |
63 | in pure lisp. If the emacs function is a subr, the parameters are obtained |
64 | from the documentation string if possible. | |
1b09702a NF |
65 | |
66 | If point is over a documented variable, print that variable's docstring | |
332ae8db | 67 | instead. |
1b09702a NF |
68 | |
69 | This variable is buffer-local.") | |
70 | (make-variable-buffer-local 'eldoc-mode) | |
71 | ||
332ae8db | 72 | (defconst eldoc-idle-delay 0.50 |
1b09702a NF |
73 | "*Number of seconds of idle time to wait before printing. |
74 | If user input arrives before this interval of time has elapsed after the | |
75 | last input, no documentation will be printed. | |
76 | ||
77 | If this variable is set to 0, no idle time is required.") | |
78 | ||
332ae8db NF |
79 | (defconst eldoc-minor-mode-string " ElDoc" |
80 | "*String to display in mode line when Eldoc Mode is enabled.") | |
81 | ||
82 | ;; Put this minor mode on the global minor-mode-alist. | |
83 | (or (assq 'eldoc-mode (default-value 'minor-mode-alist)) | |
84 | (setq-default minor-mode-alist | |
85 | (append (default-value 'minor-mode-alist) | |
86 | '((eldoc-mode eldoc-minor-mode-string))))) | |
87 | ||
88 | (defconst eldoc-argument-case 'upcase | |
1b09702a NF |
89 | "Case to display argument names of functions, as a symbol. |
90 | This has two preferred values: `upcase' or `downcase'. | |
91 | Actually, any name of a function which takes a string as an argument and | |
92 | returns another string is acceptable.") | |
93 | ||
332ae8db NF |
94 | (defvar eldoc-message-commands nil |
95 | "*Commands after which it is appropriate to print in the echo area. | |
1b09702a | 96 | |
332ae8db NF |
97 | Eldoc does not try to print function arglists, etc. after just any command, |
98 | because some commands print their own messages in the echo area and these | |
99 | functions would instantly overwrite them. But self-insert-command as well | |
100 | as most motion commands are good candidates. | |
1b09702a | 101 | |
332ae8db NF |
102 | This variable contains an obarray of symbols; it is probably best to |
103 | manipulate this data structure with the commands `eldoc-add-command' and | |
104 | `eldoc-remove-command'.") | |
1b09702a | 105 | |
332ae8db | 106 | (cond ((null eldoc-message-commands) |
1b09702a | 107 | ;; If you increase the number of buckets, keep it a prime number. |
332ae8db | 108 | (setq eldoc-message-commands (make-vector 31 0)) |
1b09702a NF |
109 | (let ((list '("self-insert-command" |
110 | "next-" "previous-" | |
111 | "forward-" "backward-" | |
112 | "beginning-of-" "end-of-" | |
113 | "goto-" | |
114 | "recenter" | |
332ae8db NF |
115 | "scroll-" |
116 | "mouse-set-point")) | |
1b09702a NF |
117 | (syms nil)) |
118 | (while list | |
119 | (setq syms (all-completions (car list) obarray 'fboundp)) | |
120 | (setq list (cdr list)) | |
121 | (while syms | |
332ae8db | 122 | (set (intern (car syms) eldoc-message-commands) t) |
1b09702a NF |
123 | (setq syms (cdr syms))))))) |
124 | ||
125 | ;; Bookkeeping; the car contains the last symbol read from the buffer. | |
126 | ;; The cdr contains the string last displayed in the echo area, so it can | |
127 | ;; be printed again if necessary without reconsing. | |
128 | (defvar eldoc-last-data '(nil . nil)) | |
129 | ||
332ae8db NF |
130 | ;; Idle timers are supported in Emacs 19.31 and later. |
131 | (defconst eldoc-use-idle-timer-p (fboundp 'run-with-idle-timer)) | |
bd3e1759 | 132 | |
332ae8db NF |
133 | ;; eldoc's timer object, if using idle timers |
134 | (defvar eldoc-timer nil) | |
135 | ||
136 | ;; idle time delay currently in use by timer. | |
137 | ;; This is used to determine if eldoc-idle-delay is changed by the user. | |
138 | (defvar eldoc-current-idle-delay eldoc-idle-delay) | |
1b09702a | 139 | |
72a9f8fd NF |
140 | ;; In emacs 19.29 and later, and XEmacs 19.13 and later, all messages are |
141 | ;; recorded in a log. Do not put eldoc messages in that log since | |
142 | ;; they are Legion. | |
143 | (defmacro eldoc-message (&rest args) | |
144 | (if (fboundp 'display-message) | |
145 | ;; XEmacs 19.13 way of preventing log messages. | |
146 | (list 'display-message '(quote no-log) (apply 'list 'format args)) | |
147 | (list 'let (list (list 'message-log-max 'nil)) | |
148 | (apply 'list 'message args)))) | |
149 | ||
1b09702a NF |
150 | \f |
151 | ;;;###autoload | |
152 | (defun eldoc-mode (&optional prefix) | |
332ae8db NF |
153 | "*Enable or disable eldoc mode. |
154 | See documentation for the variable of the same name for more details. | |
155 | ||
156 | If called interactively with no prefix argument, toggle current condition | |
157 | of the mode. | |
158 | If called with a positive or negative prefix argument, enable or disable | |
159 | the mode, respectively." | |
1b09702a NF |
160 | (interactive "P") |
161 | ||
332ae8db NF |
162 | (cond (eldoc-use-idle-timer-p |
163 | (add-hook 'post-command-hook 'eldoc-schedule-timer)) | |
164 | (t | |
165 | ;; Use post-command-idle-hook if defined, otherwise use | |
166 | ;; post-command-hook. The former is only proper to use in Emacs | |
167 | ;; 19.30; that is the first version in which it appeared, but it | |
168 | ;; was obsolesced by idle timers in Emacs 19.31. | |
169 | (add-hook (if (boundp 'post-command-idle-hook) | |
170 | 'post-command-idle-hook | |
171 | 'post-command-hook) | |
172 | 'eldoc-print-current-symbol-info))) | |
1b09702a | 173 | |
58ee38ca NF |
174 | (setq eldoc-mode (if prefix |
175 | (>= (prefix-numeric-value prefix) 0) | |
176 | (not eldoc-mode))) | |
177 | ||
1b09702a NF |
178 | (and (interactive-p) |
179 | (if eldoc-mode | |
180 | (message "eldoc-mode is enabled") | |
181 | (message "eldoc-mode is disabled"))) | |
182 | eldoc-mode) | |
183 | ||
184 | ;;;###autoload | |
185 | (defun turn-on-eldoc-mode () | |
186 | "Unequivocally turn on eldoc-mode (see variable documentation)." | |
187 | (interactive) | |
188 | (eldoc-mode 1)) | |
189 | ||
190 | (defun eldoc-add-command (cmd) | |
191 | "Add COMMAND to the list of commands which causes function arg display. | |
332ae8db | 192 | If called interactively, completion on defined commands is available. |
1b09702a NF |
193 | |
194 | When point is in a sexp, the function args are not reprinted in the echo | |
195 | area after every possible interactive command because some of them print | |
196 | their own messages in the echo area; the eldoc functions would instantly | |
197 | overwrite them unless it is more restrained." | |
332ae8db | 198 | (interactive "CAdd function to eldoc message commands list: ") |
1b09702a | 199 | (and (fboundp cmd) |
332ae8db | 200 | (set (intern (symbol-name cmd) eldoc-message-commands) t))) |
1b09702a NF |
201 | |
202 | (defun eldoc-remove-command (cmd) | |
203 | "Remove COMMAND from the list of commands which causes function arg display. | |
204 | If called interactively, completion matches only those functions currently | |
205 | in the list. | |
206 | ||
207 | When point is in a sexp, the function args are not reprinted in the echo | |
208 | area after every possible interactive command because some of them print | |
209 | their own messages in the echo area; the eldoc functions would instantly | |
210 | overwrite them unless it is more restrained." | |
211 | (interactive (list (completing-read | |
212 | "Remove function from eldoc message commands list: " | |
332ae8db | 213 | eldoc-message-commands 'boundp t))) |
1b09702a NF |
214 | (and (symbolp cmd) |
215 | (setq cmd (symbol-name cmd))) | |
216 | (if (fboundp 'unintern) | |
332ae8db NF |
217 | (unintern cmd eldoc-message-commands) |
218 | (let ((s (intern-soft cmd eldoc-message-commands))) | |
1b09702a NF |
219 | (and s |
220 | (makunbound s))))) | |
221 | ||
332ae8db NF |
222 | ;; Idle timers are part of Emacs 19.31 and later. |
223 | (defun eldoc-schedule-timer () | |
224 | (or (and eldoc-timer | |
225 | (memq eldoc-timer timer-idle-list)) | |
226 | (setq eldoc-timer | |
227 | (run-with-idle-timer eldoc-idle-delay t | |
228 | 'eldoc-print-current-symbol-info))) | |
229 | ||
230 | ;; If user has changed the idle delay, update the timer. | |
231 | (cond ((not (= eldoc-idle-delay eldoc-current-idle-delay)) | |
232 | (setq eldoc-current-idle-delay eldoc-idle-delay) | |
233 | (timer-set-idle-time eldoc-timer eldoc-idle-delay t)))) | |
234 | ||
235 | \f | |
236 | (defun eldoc-print-current-symbol-info () | |
1b09702a | 237 | (and eldoc-mode |
332ae8db NF |
238 | (not executing-kbd-macro) |
239 | ||
240 | ;; Having this mode operate in an active minibuffer makes it | |
241 | ;; impossible to what you're doing. | |
1b09702a | 242 | (not (eq (selected-window) (minibuffer-window))) |
332ae8db NF |
243 | |
244 | (cond (eldoc-use-idle-timer-p | |
245 | (and (symbolp last-command) | |
246 | (intern-soft (symbol-name last-command) | |
247 | eldoc-message-commands))) | |
248 | (t | |
249 | ;; If we don't have idle timers, this function is | |
250 | ;; running on post-command-hook directly; that means the | |
251 | ;; user's last command is still on `this-command', and we | |
252 | ;; must wait briefly for input to see whether to do display. | |
253 | (and (symbolp this-command) | |
254 | (intern-soft (symbol-name this-command) | |
255 | eldoc-message-commands) | |
256 | (sit-for eldoc-idle-delay)))) | |
257 | ||
1b09702a NF |
258 | (let ((current-symbol (eldoc-current-symbol)) |
259 | (current-fnsym (eldoc-fnsym-in-current-sexp))) | |
260 | (cond ((eq current-symbol current-fnsym) | |
261 | (eldoc-print-fnsym-args current-fnsym)) | |
262 | (t | |
263 | (or (eldoc-print-var-docstring current-symbol) | |
264 | (eldoc-print-fnsym-args current-fnsym))))))) | |
265 | ||
1b09702a | 266 | (defun eldoc-print-fnsym-args (&optional symbol) |
1b09702a NF |
267 | (interactive) |
268 | (let ((sym (or symbol (eldoc-fnsym-in-current-sexp))) | |
1b09702a NF |
269 | (args nil)) |
270 | (cond ((not (and (symbolp sym) | |
271 | (fboundp sym)))) | |
272 | ((eq sym (car eldoc-last-data)) | |
1b09702a NF |
273 | (setq args (cdr eldoc-last-data))) |
274 | ((subrp (eldoc-symbol-function sym)) | |
332ae8db NF |
275 | (setq args (or (eldoc-function-argstring-from-docstring sym) |
276 | (eldoc-docstring-first-line (documentation sym t)))) | |
277 | (setcar eldoc-last-data sym) | |
1b09702a NF |
278 | (setcdr eldoc-last-data args)) |
279 | (t | |
280 | (setq args (eldoc-function-argstring sym)) | |
332ae8db | 281 | (setcar eldoc-last-data sym) |
1b09702a NF |
282 | (setcdr eldoc-last-data args))) |
283 | (and args | |
72a9f8fd | 284 | (eldoc-message "%s: %s" sym args)))) |
1b09702a NF |
285 | |
286 | (defun eldoc-fnsym-in-current-sexp () | |
287 | (let* ((p (point)) | |
288 | (sym (progn | |
289 | (while (and (eldoc-forward-sexp-safe -1) | |
290 | (> (point) (point-min)))) | |
291 | (cond ((or (= (point) (point-min)) | |
292 | (memq (or (char-after (point)) 0) | |
293 | '(?\( ?\")) | |
294 | ;; If we hit a quotation mark before a paren, we | |
295 | ;; are inside a specific string, not a list of | |
296 | ;; symbols. | |
297 | (eq (or (char-after (1- (point))) 0) ?\")) | |
298 | nil) | |
299 | (t (condition-case nil | |
300 | (read (current-buffer)) | |
301 | (error nil))))))) | |
302 | (goto-char p) | |
303 | (and (symbolp sym) | |
304 | sym))) | |
305 | ||
306 | (defun eldoc-function-argstring (fn) | |
dd159a74 NF |
307 | (let* ((prelim-def (eldoc-symbol-function fn)) |
308 | (def (if (eq (car-safe prelim-def) 'macro) | |
309 | (cdr prelim-def) | |
310 | prelim-def)) | |
1b09702a | 311 | (arglist (cond ((null def) nil) |
dd159a74 | 312 | ((byte-code-function-p def) |
1b09702a NF |
313 | (if (fboundp 'compiled-function-arglist) |
314 | (funcall 'compiled-function-arglist def) | |
dd159a74 | 315 | (aref def 0))) |
1b09702a NF |
316 | ((eq (car-safe def) 'lambda) |
317 | (nth 1 def)) | |
318 | (t t)))) | |
319 | (eldoc-function-argstring-format arglist))) | |
320 | ||
332ae8db NF |
321 | (defun eldoc-function-argstring-format (arglist) |
322 | (cond ((not (listp arglist)) | |
323 | (setq arglist nil)) | |
324 | ((symbolp (car arglist)) | |
325 | (setq arglist | |
326 | (mapcar (function (lambda (s) | |
327 | (if (memq s '(&optional &rest)) | |
328 | (symbol-name s) | |
329 | (funcall eldoc-argument-case | |
330 | (symbol-name s))))) | |
331 | arglist))) | |
332 | ((stringp (car arglist)) | |
333 | (setq arglist | |
334 | (mapcar (function (lambda (s) | |
335 | (if (member s '("&optional" "&rest")) | |
336 | s | |
337 | (funcall eldoc-argument-case s)))) | |
338 | arglist)))) | |
339 | (concat "(" (mapconcat 'identity arglist " ") ")")) | |
340 | ||
341 | \f | |
342 | (defun eldoc-print-var-docstring (&optional sym) | |
343 | (or sym (setq sym (eldoc-current-symbol))) | |
344 | (eldoc-print-docstring sym (documentation-property | |
345 | sym 'variable-documentation t))) | |
346 | ||
347 | ;; Print the brief (one-line) documentation string for the symbol. | |
348 | (defun eldoc-print-docstring (symbol doc) | |
349 | (and doc | |
350 | (eldoc-message "%s" (eldoc-docstring-message symbol doc)))) | |
351 | ||
352 | ;; If the entire line cannot fit in the echo area, the variable name may be | |
353 | ;; truncated or eliminated entirely from the output to make room. | |
354 | ;; Any leading `*' in the docstring (which indicates the variable is a user | |
355 | ;; option) is not printed." | |
356 | (defun eldoc-docstring-message (symbol doc) | |
357 | (and doc | |
358 | (let ((name (symbol-name symbol))) | |
359 | (setq doc (eldoc-docstring-first-line doc)) | |
360 | (save-match-data | |
361 | (let* ((doclen (+ (length name) (length ": ") (length doc))) | |
362 | ;; Subtract 1 from window width since emacs seems not to | |
363 | ;; write any chars to the last column, at least for some | |
364 | ;; terminal types. | |
365 | (strip (- doclen (1- (window-width (minibuffer-window)))))) | |
366 | (cond ((> strip 0) | |
367 | (let* ((len (length name))) | |
368 | (cond ((>= strip len) | |
369 | (format "%s" doc)) | |
370 | (t | |
371 | (setq name (substring name 0 (- len strip))) | |
372 | (format "%s: %s" name doc))))) | |
373 | (t | |
374 | (format "%s: %s" symbol doc)))))))) | |
375 | ||
376 | (defun eldoc-docstring-first-line (doc) | |
377 | (save-match-data | |
378 | (and (string-match "\n" doc) | |
379 | (setq doc (substring doc 0 (match-beginning 0)))) | |
380 | (and (string-match "^\\*" doc) | |
381 | (setq doc (substring doc 1)))) | |
382 | doc) | |
383 | ||
384 | \f | |
385 | ;; Alist of predicate/action pairs. | |
386 | ;; Each member of the list is a sublist consisting of a predicate function | |
387 | ;; used to determine if the arglist for a function can be found using a | |
388 | ;; certain pattern, and a function which returns the actual arglist from | |
389 | ;; that docstring. | |
390 | ;; | |
391 | ;; The order in this table is significant, since later predicates may be | |
392 | ;; more general than earlier ones. | |
393 | ;; | |
394 | ;; Compiler note for Emacs 19.29 and later: these functions will be | |
395 | ;; compiled to bytecode, but can't be lazy-loaded even if you set | |
396 | ;; byte-compile-dynamic; to do that would require making them named | |
397 | ;; top-level defuns, and that's not particularly desirable either. | |
398 | (defconst eldoc-function-argstring-from-docstring-method-table | |
399 | (list | |
400 | ;; Try first searching for args starting with symbol name. | |
401 | ;; This is to avoid matching parenthetical remarks in e.g. sit-for. | |
402 | (list (function (lambda (doc fn) | |
403 | (string-match (format "^(%s[^\n)]*)$" fn) doc))) | |
404 | (function (lambda (doc) | |
405 | ;; end does not include trailing ")" sequence. | |
406 | (let ((end (- (match-end 0) 1))) | |
407 | (if (string-match " +" doc (match-beginning 0)) | |
408 | (substring doc (match-end 0) end) | |
409 | ""))))) | |
410 | ||
411 | ;; Try again not requiring this symbol name in the docstring. | |
412 | ;; This will be the case when looking up aliases. | |
413 | (list (function (lambda (doc fn) | |
414 | (string-match "^([^\n)]+)$" doc))) | |
415 | (function (lambda (doc) | |
416 | ;; end does not include trailing ")" sequence. | |
417 | (let ((end (- (match-end 0) 1))) | |
418 | (and (string-match " +" doc (match-beginning 0)) | |
419 | (substring doc (match-end 0) end)))))) | |
420 | ||
421 | ;; Emacs subr docstring style: | |
422 | ;; (fn arg1 arg2 ...): description... | |
423 | (list (function (lambda (doc fn) | |
424 | (string-match "^([^\n)]+):" doc))) | |
425 | (function (lambda (doc) | |
426 | ;; end does not include trailing "):" sequence. | |
427 | (let ((end (- (match-end 0) 2))) | |
428 | (and (string-match " +" doc (match-beginning 0)) | |
429 | (substring doc (match-end 0) end)))))) | |
430 | ||
431 | ;; XEmacs subr docstring style: | |
432 | ;; "arguments: (arg1 arg2 ...) | |
433 | (list (function (lambda (doc fn) | |
434 | (string-match "^arguments: (\\([^\n)]+\\))" doc))) | |
435 | (function (lambda (doc) | |
436 | ;; also skip leading paren, but the first word is | |
437 | ;; actually an argument, not the function name. | |
438 | (substring doc (match-beginning 1) (match-end 1))))) | |
439 | ||
440 | ;; This finds the argstring for `condition-case'. Any others? | |
441 | (list (function (lambda (doc fn) | |
442 | (string-match | |
443 | (format "^Usage looks like \\((%s[^\n)]*)\\)\\.$" fn) | |
444 | doc))) | |
445 | (function (lambda (doc) | |
446 | ;; end does not include trailing ")" sequence. | |
447 | (let ((end (- (match-end 1) 1))) | |
448 | (and (string-match " +" doc (match-beginning 1)) | |
449 | (substring doc (match-end 0) end)))))) | |
450 | ||
451 | ;; This finds the argstring for `setq-default'. Any others? | |
452 | (list (function (lambda (doc fn) | |
453 | (string-match (format "^[ \t]+\\((%s[^\n)]*)\\)$" fn) | |
454 | doc))) | |
455 | (function (lambda (doc) | |
456 | ;; end does not include trailing ")" sequence. | |
457 | (let ((end (- (match-end 1) 1))) | |
458 | (and (string-match " +" doc (match-beginning 1)) | |
459 | (substring doc (match-end 0) end)))))) | |
460 | ||
461 | ;; This finds the argstring for `start-process'. Any others? | |
462 | (list (function (lambda (doc fn) | |
463 | (string-match "^Args are +\\([^\n]+\\)$" doc))) | |
464 | (function (lambda (doc) | |
465 | (substring doc (match-beginning 1) (match-end 1))))) | |
466 | )) | |
467 | ||
1b09702a NF |
468 | (defun eldoc-function-argstring-from-docstring (fn) |
469 | (let ((docstring (documentation fn 'raw)) | |
332ae8db | 470 | (table eldoc-function-argstring-from-docstring-method-table) |
1b09702a | 471 | (doc nil) |
332ae8db | 472 | (doclist nil)) |
1b09702a | 473 | (save-match-data |
332ae8db NF |
474 | (while table |
475 | (cond ((funcall (car (car table)) docstring fn) | |
476 | (setq doc (funcall (car (cdr (car table))) docstring)) | |
477 | (setq table nil)) | |
478 | (t | |
479 | (setq table (cdr table))))) | |
1b09702a NF |
480 | |
481 | (cond ((not (stringp doc)) | |
482 | nil) | |
483 | ((string-match "&" doc) | |
484 | (let ((p 0) | |
485 | (l (length doc))) | |
486 | (while (< p l) | |
487 | (cond ((string-match "[ \t\n]+" doc p) | |
488 | (setq doclist | |
489 | (cons (substring doc p (match-beginning 0)) | |
490 | doclist)) | |
491 | (setq p (match-end 0))) | |
492 | (t | |
493 | (setq doclist (cons (substring doc p) doclist)) | |
494 | (setq p l)))) | |
495 | (eldoc-function-argstring-format (nreverse doclist)))) | |
496 | (t | |
497 | (concat "(" (funcall eldoc-argument-case doc) ")")))))) | |
498 | ||
1b09702a NF |
499 | \f |
500 | ;; forward-sexp calls scan-sexps, which returns an error if it hits the | |
501 | ;; beginning or end of the sexp. This returns nil instead. | |
502 | (defun eldoc-forward-sexp-safe (&optional count) | |
503 | "Move forward across one balanced expression (sexp). | |
504 | With argument, do it that many times. Negative arg -COUNT means | |
505 | move backward across COUNT balanced expressions. | |
506 | Return distance in buffer moved, or nil." | |
507 | (or count (setq count 1)) | |
508 | (condition-case err | |
509 | (- (- (point) (progn | |
510 | (let ((parse-sexp-ignore-comments t)) | |
511 | (forward-sexp count)) | |
512 | (point)))) | |
513 | (error nil))) | |
514 | ||
515 | ;; Do indirect function resolution if possible. | |
516 | (defun eldoc-symbol-function (fsym) | |
517 | (let ((defn (and (fboundp fsym) | |
518 | (symbol-function fsym)))) | |
519 | (and (symbolp defn) | |
520 | (condition-case err | |
521 | (setq defn (indirect-function fsym)) | |
522 | (error (setq defn nil)))) | |
523 | defn)) | |
524 | ||
525 | (defun eldoc-current-symbol () | |
526 | (let ((c (char-after (point)))) | |
527 | (and c | |
528 | (memq (char-syntax c) '(?w ?_)) | |
529 | (intern-soft (current-word))))) | |
530 | ||
531 | (provide 'eldoc) | |
532 | ||
533 | ;;; eldoc.el ends here |