simple.el 153 KB
Newer Older
Eric S. Raymond's avatar
Eric S. Raymond committed
1 2
;;; simple.el --- basic editing commands for Emacs

3
;; Copyright (C) 1985, 86, 87, 93, 94, 95, 96, 97, 98, 99, 2000, 2001
4
;;        Free Software Foundation, Inc.
Jim Blandy's avatar
Jim Blandy committed
5 6 7 8 9

;; This file is part of GNU Emacs.

;; GNU Emacs is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
Eric S. Raymond's avatar
Eric S. Raymond committed
10
;; the Free Software Foundation; either version 2, or (at your option)
Jim Blandy's avatar
Jim Blandy committed
11 12 13 14 15 16 17 18
;; any later version.

;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
Erik Naggum's avatar
Erik Naggum committed
19 20 21
;; along with GNU Emacs; see the file COPYING.  If not, write to the
;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.
Jim Blandy's avatar
Jim Blandy committed
22

23 24 25 26 27
;;; Commentary:

;; A grab-bag of basic Emacs commands not specifically related to some
;; major mode or to file-handling.

Eric S. Raymond's avatar
Eric S. Raymond committed
28
;;; Code:
Jim Blandy's avatar
Jim Blandy committed
29

Gerd Moellmann's avatar
Gerd Moellmann committed
30
(eval-when-compile
31
  (autoload 'widget-convert "wid-edit")
Dave Love's avatar
Dave Love committed
32
  (autoload 'shell-mode "shell")
Gerd Moellmann's avatar
Gerd Moellmann committed
33 34 35
  (require 'cl))


36 37 38 39 40 41 42 43 44
(defgroup killing nil
  "Killing and yanking commands"
  :group 'editing)

(defgroup paren-matching nil
  "Highlight (un)matching of parens and expressions."
  :group 'matching)


Karl Heuer's avatar
Karl Heuer committed
45 46 47 48 49
(defun fundamental-mode ()
  "Major mode not specialized for anything in particular.
Other major modes are defined by comparison with this one."
  (interactive)
  (kill-all-local-variables))
50

Karl Heuer's avatar
Karl Heuer committed
51 52
;; Making and deleting lines.

53
(defun newline (&optional arg)
54
  "Insert a newline, and move to left margin of the new line if it's blank.
55
The newline is marked with the text-property `hard'.
56
With ARG, insert that many newlines.
57 58
In Auto Fill mode, if no numeric arg, break the preceding line if it's long."
  (interactive "*P")
59
  (barf-if-buffer-read-only)
60 61 62 63
  ;; Inserting a newline at the end of a line produces better redisplay in
  ;; try_window_id than inserting at the beginning of a line, and the textual
  ;; result is the same.  So, if we're at beginning of line, pretend to be at
  ;; the end of the previous line.
64
  (let ((flag (and (not (bobp))
65
		   (bolp)
66 67 68 69
		   ;; Make sure no functions want to be told about
		   ;; the range of the changes.
		   (not after-change-functions)
		   (not before-change-functions)
70 71
		   ;; Make sure there are no markers here.
		   (not (buffer-has-markers-at (1- (point))))
72
		   (not (buffer-has-markers-at (point)))
73 74 75 76 77 78
		   ;; Make sure no text properties want to know
		   ;; where the change was.
		   (not (get-char-property (1- (point)) 'modification-hooks))
		   (not (get-char-property (1- (point)) 'insert-behind-hooks))
		   (or (eobp)
		       (not (get-char-property (point) 'insert-in-front-hooks)))
79 80 81 82 83 84 85 86
		   ;; Make sure the newline before point isn't intangible.
		   (not (get-char-property (1- (point)) 'intangible))
		   ;; Make sure the newline before point isn't read-only.
		   (not (get-char-property (1- (point)) 'read-only))
		   ;; Make sure the newline before point isn't invisible.
		   (not (get-char-property (1- (point)) 'invisible))
		   ;; Make sure the newline before point has the same
		   ;; properties as the char before it (if any).
87
		   (< (or (previous-property-change (point)) -2)
88 89 90 91
		      (- (point) 2))))
	(was-page-start (and (bolp)
			     (looking-at page-delimiter)))
	(beforepos (point)))
92 93 94 95 96
    (if flag (backward-char 1))
    ;; Call self-insert so that auto-fill, abbrev expansion etc. happens.
    ;; Set last-command-char to tell self-insert what to insert.
    (let ((last-command-char ?\n)
	  ;; Don't auto-fill if we have a numeric argument.
97 98 99
	  ;; Also not if flag is true (it would fill wrong line);
	  ;; there is no need to since we're at BOL.
	  (auto-fill-function (if (or arg flag) nil auto-fill-function)))
100 101 102 103
      (unwind-protect
	  (self-insert-command (prefix-numeric-value arg))
	;; If we get an error in self-insert-command, put point at right place.
	(if flag (forward-char 1))))
104 105 106 107
    ;; Even if we did *not* get an error, keep that forward-char;
    ;; all further processing should apply to the newline that the user
    ;; thinks he inserted.

108 109
    ;; Mark the newline(s) `hard'.
    (if use-hard-newlines
110
	(set-hard-newline-properties
111
	 (- (point) (if arg (prefix-numeric-value arg) 1)) (point)))
112 113 114 115 116 117 118 119 120 121 122 123 124 125
    ;; If the newline leaves the previous line blank,
    ;; and we have a left margin, delete that from the blank line.
    (or flag
	(save-excursion
	  (goto-char beforepos)
	  (beginning-of-line)
	  (and (looking-at "[ \t]$")
	       (> (current-left-margin) 0)
	       (delete-region (point) (progn (end-of-line) (point))))))
    ;; Indent the line after the newline, except in one case:
    ;; when we added the newline at the beginning of a line
    ;; which starts a page.
    (or was-page-start
	(move-to-left-margin nil t)))
126 127
  nil)

128 129 130 131 132 133 134
(defun set-hard-newline-properties (from to)
  (let ((sticky (get-text-property from 'rear-nonsticky)))
    (put-text-property from to 'hard 't)
    ;; If rear-nonsticky is not "t", add 'hard to rear-nonsticky list
    (if (and (listp sticky) (not (memq 'hard sticky)))
	(put-text-property from (point) 'rear-nonsticky
			   (cons 'hard sticky)))))
135

Jim Blandy's avatar
Jim Blandy committed
136
(defun open-line (arg)
137
  "Insert a newline and leave point before it.
138
If there is a fill prefix and/or a left-margin, insert them on the new line
139
if the line would have been blank.
140
With arg N, insert N newlines."
Jim Blandy's avatar
Jim Blandy committed
141
  (interactive "*p")
142
  (let* ((do-fill-prefix (and fill-prefix (bolp)))
143
	 (do-left-margin (and (bolp) (> (current-left-margin) 0)))
144 145 146
	 (loc (point))
	 ;; Don't expand an abbrev before point.
	 (abbrev-mode nil))
147 148
    (newline arg)
    (goto-char loc)
149
    (while (> arg 0)
150 151 152 153
      (cond ((bolp)
	     (if do-left-margin (indent-to (current-left-margin)))
	     (if do-fill-prefix (insert-and-inherit fill-prefix))))
      (forward-line 1)
154
      (setq arg (1- arg)))
155 156
    (goto-char loc)
    (end-of-line)))
Jim Blandy's avatar
Jim Blandy committed
157 158 159 160 161 162 163

(defun split-line ()
  "Split current line, moving portion beyond point vertically down."
  (interactive "*")
  (skip-chars-forward " \t")
  (let ((col (current-column))
	(pos (point)))
164
    (newline 1)
Jim Blandy's avatar
Jim Blandy committed
165 166 167 168 169
    (indent-to col 0)
    (goto-char pos)))

(defun delete-indentation (&optional arg)
  "Join this line to previous and fix up whitespace at join.
170
If there is a fill prefix, delete it from the beginning of this line.
Jim Blandy's avatar
Jim Blandy committed
171 172 173 174 175 176 177
With argument, join this line to following line."
  (interactive "*P")
  (beginning-of-line)
  (if arg (forward-line 1))
  (if (eq (preceding-char) ?\n)
      (progn
	(delete-region (point) (1- (point)))
178 179 180
	;; If the second line started with the fill prefix,
	;; delete the prefix.
	(if (and fill-prefix
181
		 (<= (+ (point) (length fill-prefix)) (point-max))
182 183 184 185
		 (string= fill-prefix
			  (buffer-substring (point)
					    (+ (point) (length fill-prefix)))))
	    (delete-region (point) (+ (point) (length fill-prefix))))
Jim Blandy's avatar
Jim Blandy committed
186 187
	(fixup-whitespace))))

Dave Love's avatar
Dave Love committed
188
(defalias 'join-line #'delete-indentation) ; easier to find
189

Jim Blandy's avatar
Jim Blandy committed
190 191 192
(defun delete-blank-lines ()
  "On blank line, delete all surrounding blank lines, leaving just one.
On isolated blank line, delete that one.
193
On nonblank line, delete any immediately following blank lines."
Jim Blandy's avatar
Jim Blandy committed
194 195 196 197 198
  (interactive "*")
  (let (thisblank singleblank)
    (save-excursion
      (beginning-of-line)
      (setq thisblank (looking-at "[ \t]*$"))
Jim Blandy's avatar
Jim Blandy committed
199
      ;; Set singleblank if there is just one blank line here.
Jim Blandy's avatar
Jim Blandy committed
200 201 202 203 204 205
      (setq singleblank
	    (and thisblank
		 (not (looking-at "[ \t]*\n[ \t]*$"))
		 (or (bobp)
		     (progn (forward-line -1)
			    (not (looking-at "[ \t]*$")))))))
Jim Blandy's avatar
Jim Blandy committed
206
    ;; Delete preceding blank lines, and this one too if it's the only one.
Jim Blandy's avatar
Jim Blandy committed
207 208 209 210 211 212 213 214
    (if thisblank
	(progn
	  (beginning-of-line)
	  (if singleblank (forward-line 1))
	  (delete-region (point)
			 (if (re-search-backward "[^ \t\n]" nil t)
			     (progn (forward-line 1) (point))
			   (point-min)))))
Jim Blandy's avatar
Jim Blandy committed
215 216
    ;; Delete following blank lines, unless the current line is blank
    ;; and there are no following blank lines.
Jim Blandy's avatar
Jim Blandy committed
217 218 219 220 221 222 223
    (if (not (and thisblank singleblank))
	(save-excursion
	  (end-of-line)
	  (forward-line 1)
	  (delete-region (point)
			 (if (re-search-forward "[^ \t\n]" nil t)
			     (progn (beginning-of-line) (point))
Jim Blandy's avatar
Jim Blandy committed
224 225 226 227 228
			   (point-max)))))
    ;; Handle the special case where point is followed by newline and eob.
    ;; Delete the line, leaving point at eob.
    (if (looking-at "^[ \t]*\n\\'")
	(delete-region (point) (point-max)))))
Jim Blandy's avatar
Jim Blandy committed
229

230 231 232 233 234 235 236 237
(defun delete-trailing-whitespace ()
  "Delete all the trailing whitespace across the current buffer.
All whitespace after the last non-whitespace character in a line is deleted.
This respects narrowing, created by \\[narrow-to-region] and friends."
  (interactive "*")
  (save-match-data
    (save-excursion
      (goto-char (point-min))
238 239
      (while (re-search-forward "\\s-$" nil t)
	(skip-syntax-backward "-" (save-excursion (forward-line 0) (point)))
240 241 242
	;; Don't delete formfeeds, even if they are considered whitespace.
	(if (looking-at ".*\f")
	    (goto-char (match-end 0)))
243
	(delete-region (point) (match-end 0))))))
244

Jim Blandy's avatar
Jim Blandy committed
245 246
(defun newline-and-indent ()
  "Insert a newline, then indent according to major mode.
247
Indentation is done using the value of `indent-line-function'.
Jim Blandy's avatar
Jim Blandy committed
248
In programming language modes, this is the same as TAB.
249
In some text modes, where TAB inserts a tab, this command indents to the
250
column specified by the function `current-left-margin'."
Jim Blandy's avatar
Jim Blandy committed
251
  (interactive "*")
252
  (delete-horizontal-space t)
Jim Blandy's avatar
Jim Blandy committed
253
  (newline)
Jim Blandy's avatar
Jim Blandy committed
254 255 256 257 258
  (indent-according-to-mode))

(defun reindent-then-newline-and-indent ()
  "Reindent current line, insert newline, then indent the new line.
Indentation of both lines is done according to the current major mode,
259
which means calling the current value of `indent-line-function'.
Jim Blandy's avatar
Jim Blandy committed
260 261
In programming language modes, this is the same as TAB.
In some text modes, where TAB inserts a tab, this indents to the
262
column specified by the function `current-left-margin'."
Jim Blandy's avatar
Jim Blandy committed
263 264
  (interactive "*")
  (save-excursion
265
    (delete-horizontal-space t)
Jim Blandy's avatar
Jim Blandy committed
266
    (indent-according-to-mode))
Jim Blandy's avatar
Jim Blandy committed
267
  (newline)
Jim Blandy's avatar
Jim Blandy committed
268
  (indent-according-to-mode))
269

Karl Heuer's avatar
Karl Heuer committed
270 271 272
(defun quoted-insert (arg)
  "Read next input character and insert it.
This is useful for inserting control characters.
Jim Blandy's avatar
Jim Blandy committed
273

Karl Heuer's avatar
Karl Heuer committed
274 275 276 277 278 279
If the first character you type after this command is an octal digit,
you should type a sequence of octal digits which specify a character code.
Any nondigit terminates the sequence.  If the terminator is a RET,
it is discarded; any other terminator is used itself as input.
The variable `read-quoted-char-radix' specifies the radix for this feature;
set it to 10 or 16 to use decimal or hex instead of octal.
280

Karl Heuer's avatar
Karl Heuer committed
281 282 283 284
In overwrite mode, this function inserts the character anyway, and
does not handle octal digits specially.  This means that if you use
overwrite as your normal editing mode, you can use this function to
insert characters when necessary.
285

Karl Heuer's avatar
Karl Heuer committed
286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306
In binary overwrite mode, this function does overwrite, and octal
digits are interpreted as a character code.  This is intended to be
useful for editing binary files."
  (interactive "*p")
  (let ((char (if (or (not overwrite-mode)
		      (eq overwrite-mode 'overwrite-mode-binary))
		  (read-quoted-char)
		(read-char))))
    ;; Assume character codes 0240 - 0377 stand for characters in some
    ;; single-byte character set, and convert them to Emacs
    ;; characters.
    (if (and enable-multibyte-characters
	     (>= char ?\240)
	     (<= char ?\377))
	(setq char (unibyte-char-to-multibyte char)))
    (if (> arg 0)
	(if (eq overwrite-mode 'overwrite-mode-binary)
	    (delete-char arg)))
    (while (> arg 0)
      (insert-and-inherit char)
      (setq arg (1- arg)))))
307

Karl Heuer's avatar
Karl Heuer committed
308 309 310 311 312
(defun forward-to-indentation (arg)
  "Move forward ARG lines and position at first nonblank character."
  (interactive "p")
  (forward-line arg)
  (skip-chars-forward " \t"))
313

Karl Heuer's avatar
Karl Heuer committed
314 315 316 317 318
(defun backward-to-indentation (arg)
  "Move backward ARG lines and position at first nonblank character."
  (interactive "p")
  (forward-line (- arg))
  (skip-chars-forward " \t"))
Jim Blandy's avatar
Jim Blandy committed
319

Karl Heuer's avatar
Karl Heuer committed
320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337
(defun back-to-indentation ()
  "Move point to the first non-whitespace character on this line."
  (interactive)
  (beginning-of-line 1)
  (skip-chars-forward " \t"))

(defun fixup-whitespace ()
  "Fixup white space between objects around point.
Leave one space or none, according to the context."
  (interactive "*")
  (save-excursion
    (delete-horizontal-space)
    (if (or (looking-at "^\\|\\s)")
	    (save-excursion (forward-char -1)
			    (looking-at "$\\|\\s(\\|\\s'")))
	nil
      (insert ?\ ))))

338 339 340
(defun delete-horizontal-space (&optional backward-only)
  "Delete all spaces and tabs around point.
If BACKWARD-ONLY is non-nil, only delete spaces before point."
Karl Heuer's avatar
Karl Heuer committed
341
  (interactive "*")
342 343 344 345 346 347 348 349 350
  (delete-region
   (if backward-only
       (point)
     (progn
       (skip-chars-forward " \t" (field-end))
       (point)))
   (progn
     (skip-chars-backward " \t" (field-beginning nil t))
     (point))))
Karl Heuer's avatar
Karl Heuer committed
351 352 353 354

(defun just-one-space ()
  "Delete all spaces and tabs around point, leaving one space."
  (interactive "*")
355
  (skip-chars-backward " \t" (field-beginning))
Karl Heuer's avatar
Karl Heuer committed
356 357 358
  (if (= (following-char) ? )
      (forward-char 1)
    (insert ? ))
359 360 361 362 363
  (delete-region
   (point)
   (progn
     (skip-chars-forward " \t" (field-end nil t))
     (point))))
364

Jim Blandy's avatar
Jim Blandy committed
365 366
(defun beginning-of-buffer (&optional arg)
  "Move point to the beginning of the buffer; leave mark at previous position.
367 368 369 370
With arg N, put point N/10 of the way from the beginning.

If the buffer is narrowed, this command uses the beginning and size
of the accessible part of the buffer.
371 372

Don't use this command in Lisp programs!
Jim Blandy's avatar
Jim Blandy committed
373 374 375
\(goto-char (point-min)) is faster and avoids clobbering the mark."
  (interactive "P")
  (push-mark)
376 377 378 379 380 381 382 383 384
  (let ((size (- (point-max) (point-min))))
    (goto-char (if arg
		   (+ (point-min)
		      (if (> size 10000)
			  ;; Avoid overflow for large buffer sizes!
			  (* (prefix-numeric-value arg)
			     (/ size 10))
			(/ (+ 10 (* size (prefix-numeric-value arg))) 10)))
		 (point-min))))
Jim Blandy's avatar
Jim Blandy committed
385 386 387 388
  (if arg (forward-line 1)))

(defun end-of-buffer (&optional arg)
  "Move point to the end of the buffer; leave mark at previous position.
389 390 391 392
With arg N, put point N/10 of the way from the end.

If the buffer is narrowed, this command uses the beginning and size
of the accessible part of the buffer.
393 394

Don't use this command in Lisp programs!
Jim Blandy's avatar
Jim Blandy committed
395 396 397
\(goto-char (point-max)) is faster and avoids clobbering the mark."
  (interactive "P")
  (push-mark)
398 399 400 401 402 403 404 405 406
  (let ((size (- (point-max) (point-min))))
    (goto-char (if arg
		   (- (point-max)
		      (if (> size 10000)
			  ;; Avoid overflow for large buffer sizes!
			  (* (prefix-numeric-value arg)
			     (/ size 10))
			(/ (* size (prefix-numeric-value arg)) 10)))
		 (point-max))))
Eric S. Raymond's avatar
Eric S. Raymond committed
407 408
  ;; If we went to a place in the middle of the buffer,
  ;; adjust it to the beginning of a line.
409 410 411 412 413 414
  (cond (arg (forward-line 1))
	((< (point) (window-end nil t))
	 ;; If the end of the buffer is not already on the screen,
	 ;; then scroll specially to put it near, but not at, the bottom.
	 (overlay-recenter (point))
	 (recenter -3))))
Jim Blandy's avatar
Jim Blandy committed
415 416

(defun mark-whole-buffer ()
Jim Blandy's avatar
Jim Blandy committed
417 418 419 420
  "Put point at beginning and mark at end of buffer.
You probably should not use this function in Lisp programs;
it is usually a mistake for a Lisp function to use any subroutine
that uses or sets the mark."
Jim Blandy's avatar
Jim Blandy committed
421 422
  (interactive)
  (push-mark (point))
423
  (push-mark (point-max) nil t)
Jim Blandy's avatar
Jim Blandy committed
424
  (goto-char (point-min)))
425

426

Karl Heuer's avatar
Karl Heuer committed
427 428 429 430 431 432 433 434 435 436 437 438
;; Counting lines, one way or another.

(defun goto-line (arg)
  "Goto line ARG, counting from line 1 at beginning of buffer."
  (interactive "NGoto line: ")
  (setq arg (prefix-numeric-value arg))
  (save-restriction
    (widen)
    (goto-char 1)
    (if (eq selective-display t)
	(re-search-forward "[\n\C-m]" nil 'end (1- arg))
      (forward-line (1- arg)))))
Jim Blandy's avatar
Jim Blandy committed
439 440

(defun count-lines-region (start end)
441
  "Print number of lines and characters in the region."
Jim Blandy's avatar
Jim Blandy committed
442 443 444 445 446
  (interactive "r")
  (message "Region has %d lines, %d characters"
	   (count-lines start end) (- end start)))

(defun what-line ()
447
  "Print the current buffer line number and narrowed line number of point."
Jim Blandy's avatar
Jim Blandy committed
448
  (interactive)
449
  (let ((opoint (point)) start)
Jim Blandy's avatar
Jim Blandy committed
450
    (save-excursion
451 452 453 454 455 456 457 458 459 460 461 462 463
      (save-restriction
	(goto-char (point-min))
	(widen)
	(beginning-of-line)
	(setq start (point))
	(goto-char opoint)
	(beginning-of-line)
	(if (/= start 1)
	    (message "line %d (narrowed line %d)"
		     (1+ (count-lines 1 (point)))
		     (1+ (count-lines start (point))))
	  (message "Line %d" (1+ (count-lines 1 (point)))))))))

Jim Blandy's avatar
Jim Blandy committed
464 465 466
(defun count-lines (start end)
  "Return number of lines between START and END.
This is usually the number of newlines between them,
467
but can be one more if START is not equal to END
Jim Blandy's avatar
Jim Blandy committed
468
and the greater of them is not at the start of a line."
469 470 471 472 473 474
  (save-excursion
    (save-restriction
      (narrow-to-region start end)
      (goto-char (point-min))
      (if (eq selective-display t)
	  (save-match-data
475 476 477 478 479
	    (let ((done 0))
	      (while (re-search-forward "[\n\C-m]" nil t 40)
		(setq done (+ 40 done)))
	      (while (re-search-forward "[\n\C-m]" nil t 1)
		(setq done (+ 1 done)))
480 481 482 483
	      (goto-char (point-max))
	      (if (and (/= start end)
		       (not (bolp)))
		  (1+ done)
484 485
		done)))
	(- (buffer-size) (forward-line (buffer-size)))))))
486

487 488
(defun what-cursor-position (&optional detail)
  "Print info on cursor position (on screen and within buffer).
489
Also describe the character after point, and give its character code
490 491 492 493 494 495 496
in octal, decimal and hex.

For a non-ASCII multibyte character, also give its encoding in the
buffer's selected coding system if the coding system encodes the
character safely.  If the character is encoded into one byte, that
code is shown in hex.  If the character is encoded into more than one
byte, just \"...\" is shown.
497

498 499
In addition, with prefix argument, show details about that character
in *Help* buffer.  See also the command `describe-char-after'."
500
  (interactive "P")
Jim Blandy's avatar
Jim Blandy committed
501 502 503 504 505 506 507 508 509 510 511 512 513 514 515
  (let* ((char (following-char))
	 (beg (point-min))
	 (end (point-max))
         (pos (point))
	 (total (buffer-size))
	 (percent (if (> total 50000)
		      ;; Avoid overflow from multiplying by 100!
		      (/ (+ (/ total 200) (1- pos)) (max (/ total 100) 1))
		    (/ (+ (/ total 2) (* 100 (1- pos))) (max total 1))))
	 (hscroll (if (= (window-hscroll) 0)
		      ""
		    (format " Hscroll=%d" (window-hscroll))))
	 (col (current-column)))
    (if (= pos end)
	(if (or (/= beg 1) (/= end (1+ total)))
516
	    (message "point=%d of %d (%d%%) <%d - %d> column %d %s"
Jim Blandy's avatar
Jim Blandy committed
517
		     pos total percent beg end col hscroll)
518
	  (message "point=%d of %d (%d%%) column %d %s"
Jim Blandy's avatar
Jim Blandy committed
519
		   pos total percent col hscroll))
520 521 522 523 524
      (let ((coding buffer-file-coding-system)
	    encoded encoding-msg)
	(if (or (not coding)
		(eq (coding-system-type coding) t))
	    (setq coding default-buffer-file-coding-system))
525 526 527 528 529 530
	(if (not (char-valid-p char))
	    (setq encoding-msg
		  (format "(0%o, %d, 0x%x, invalid)" char char char))
	  (setq encoded (and (>= char 128) (encode-coding-char char coding)))
	  (setq encoding-msg
		(if encoded
531
		    (format "(0%o, %d, 0x%x, file %s)"
532
			    char char char
533
			    (if (> (length encoded) 1)
534
				"..."
535
			      (encoded-string-description encoded coding)))
536
		  (format "(0%o, %d, 0x%x)" char char char))))
537
	(if detail
538 539 540 541
	    ;; We show the detailed information about CHAR.
	    (describe-char-after (point)))
	(if (or (/= beg 1) (/= end (1+ total)))
	    (message "Char: %s %s point=%d of %d (%d%%) <%d - %d> column %d %s"
542 543
		     (if (< char 256)
			 (single-key-description char)
544
		       (buffer-substring-no-properties (point) (1+ (point))))
545 546 547 548 549 550
		     encoding-msg pos total percent beg end col hscroll)
	  (message "Char: %s %s point=%d of %d (%d%%) column %d %s"
		   (if (< char 256)
		       (single-key-description char)
		     (buffer-substring-no-properties (point) (1+ (point))))
		   encoding-msg pos total percent col hscroll))))))
551

552 553 554 555 556
(defvar read-expression-map
  (let ((m (make-sparse-keymap)))
    (define-key m "\M-\t" 'lisp-complete-symbol)
    (set-keymap-parent m minibuffer-local-map)
    m)
557 558
  "Minibuffer keymap used for reading Lisp expressions.")

559 560
(defvar read-expression-history nil)

561 562 563 564 565 566 567 568 569
(defcustom eval-expression-print-level 4
  "*Value to use for `print-level' when printing value in `eval-expression'."
  :group 'lisp
  :type 'integer
  :version "21.1")

(defcustom eval-expression-print-length 12
  "*Value to use for `print-length' when printing value in `eval-expression'."
  :group 'lisp
570
  :type '(choice (const nil) integer)
571 572 573
  :version "21.1")

(defcustom eval-expression-debug-on-error t
574 575
  "*Non-nil means set `debug-on-error' when evaluating in `eval-expression'.
If nil, don't change the value of `debug-on-error'."
576 577 578 579
  :group 'lisp
  :type 'boolean
  :version "21.1")

580
;; We define this, rather than making `eval' interactive,
Jim Blandy's avatar
Jim Blandy committed
581
;; for the sake of completion of names like eval-region, eval-current-buffer.
582 583
(defun eval-expression (eval-expression-arg
			&optional eval-expression-insert-value)
Eli Zaretskii's avatar
Eli Zaretskii committed
584 585 586 587 588
  "Evaluate EVAL-EXPRESSION-ARG and print value in the echo area.
Value is also consed on to front of the variable `values'.
Optional argument EVAL-EXPRESSION-INSERT-VALUE, if non-nil, means
insert the result into the current buffer instead of printing it in
the echo area."
589
  (interactive
590 591
   (list (read-from-minibuffer "Eval: "
			       nil read-expression-map t
592 593
			       'read-expression-history)
	 current-prefix-arg))
594

595 596 597 598 599 600 601 602 603 604 605 606
  (if (null eval-expression-debug-on-error)
      (setq values (cons (eval eval-expression-arg) values))
    (let ((old-value (make-symbol "t")) new-value)
      ;; Bind debug-on-error to something unique so that we can
      ;; detect when evaled code changes it.
      (let ((debug-on-error old-value))
	(setq values (cons (eval eval-expression-arg) values))
	(setq new-value debug-on-error))
      ;; If evaled code has changed the value of debug-on-error,
      ;; propagate that change to the global binding.
      (unless (eq old-value new-value)
	(setq debug-on-error new-value))))
607

608 609 610 611
  (let ((print-length eval-expression-print-length)
	(print-level eval-expression-print-level))
    (prin1 (car values)
	   (if eval-expression-insert-value (current-buffer) t))))
Jim Blandy's avatar
Jim Blandy committed
612 613 614 615 616

(defun edit-and-eval-command (prompt command)
  "Prompting with PROMPT, let user edit COMMAND and eval result.
COMMAND is a Lisp expression.  Let user edit that expression in
the minibuffer, then read and evaluate the result."
617 618 619 620
  (let ((command (read-from-minibuffer prompt
				       (prin1-to-string command)
				       read-expression-map t
				       '(command-history . 1))))
621
    ;; If command was added to command-history as a string,
622
    ;; get rid of that.  We want only evaluable expressions there.
623 624 625 626 627 628 629
    (if (stringp (car command-history))
	(setq command-history (cdr command-history)))

    ;; If command to be redone does not match front of history,
    ;; add it to the history.
    (or (equal command (car command-history))
	(setq command-history (cons command command-history)))
Jim Blandy's avatar
Jim Blandy committed
630 631
    (eval command)))

632
(defun repeat-complex-command (arg)
Jim Blandy's avatar
Jim Blandy committed
633 634 635 636 637 638
  "Edit and re-evaluate last complex command, or ARGth from last.
A complex command is one which used the minibuffer.
The command is placed in the minibuffer as a Lisp form for editing.
The result is executed, repeating the command as changed.
If the command has been changed or is not the most recent previous command
it is added to the front of the command history.
639 640
You can use the minibuffer history commands \\<minibuffer-local-map>\\[next-history-element] and \\[previous-history-element]
to get different commands to edit and resubmit."
Jim Blandy's avatar
Jim Blandy committed
641
  (interactive "p")
642
  (let ((elt (nth (1- arg) command-history))
Jim Blandy's avatar
Jim Blandy committed
643 644
	newcmd)
    (if elt
645
	(progn
646
	  (setq newcmd
647 648
		(let ((print-level nil)
		      (minibuffer-history-position arg)
649
		      (minibuffer-history-sexp-flag (1+ (minibuffer-depth))))
650 651 652
		  (read-from-minibuffer
		   "Redo: " (prin1-to-string elt) read-expression-map t
		   (cons 'command-history arg))))
653

654
	  ;; If command was added to command-history as a string,
655
	  ;; get rid of that.  We want only evaluable expressions there.
656 657 658 659 660 661 662
	  (if (stringp (car command-history))
	      (setq command-history (cdr command-history)))

	  ;; If command to be redone does not match front of history,
	  ;; add it to the history.
	  (or (equal newcmd (car command-history))
	      (setq command-history (cons newcmd command-history)))
Jim Blandy's avatar
Jim Blandy committed
663 664
	  (eval newcmd))
      (ding))))
665

666 667 668 669 670
(defvar minibuffer-history nil
  "Default minibuffer history list.
This is used for all minibuffer input
except when an alternate history list is specified.")
(defvar minibuffer-history-sexp-flag nil
671
  "Non-nil when doing history operations on `command-history'.
672
More generally, indicates that the history list being acted on
673 674 675
contains expressions rather than strings.
It is only valid if its value equals the current minibuffer depth,
to handle recursive uses of the minibuffer.")
676 677
(setq minibuffer-history-variable 'minibuffer-history)
(setq minibuffer-history-position nil)
678
(defvar minibuffer-history-search-history nil)
679

Jim Blandy's avatar
Jim Blandy committed
680
(mapcar
681 682 683 684 685 686 687 688 689 690
 (lambda (key-and-command)
   (mapcar
    (lambda (keymap-and-completionp)
      ;; Arg is (KEYMAP-SYMBOL . COMPLETION-MAP-P).
      ;; If the cdr of KEY-AND-COMMAND (the command) is a cons,
      ;; its car is used if COMPLETION-MAP-P is nil, its cdr if it is t.
      (define-key (symbol-value (car keymap-and-completionp))
	(car key-and-command)
	(let ((command (cdr key-and-command)))
	  (if (consp command)
691 692 693 694
	      ;; (and ... nil) => ... turns back on the completion-oriented
	      ;; history commands which rms turned off since they seem to
	      ;; do things he doesn't like.
	      (if (and (cdr keymap-and-completionp) nil) ;XXX turned off
695
		  (progn (error "EMACS BUG!") (cdr command))
696 697 698 699 700 701 702
		(car command))
	    command))))
    '((minibuffer-local-map . nil)
      (minibuffer-local-ns-map . nil)
      (minibuffer-local-completion-map . t)
      (minibuffer-local-must-match-map . t)
      (read-expression-map . nil))))
703 704 705 706
 '(("\en" . (next-history-element . next-complete-history-element))
   ([next] . (next-history-element . next-complete-history-element))
   ("\ep" . (previous-history-element . previous-complete-history-element))
   ([prior] . (previous-history-element . previous-complete-history-element))
Jim Blandy's avatar
Jim Blandy committed
707 708
   ("\er" . previous-matching-history-element)
   ("\es" . next-matching-history-element)))
709

710 711 712 713 714 715 716 717 718 719
(defvar minibuffer-text-before-history nil
  "Text that was in this minibuffer before any history commands.
This is nil if there have not yet been any history commands
in this use of the minibuffer.")

(add-hook 'minibuffer-setup-hook 'minibuffer-history-initialize)

(defun minibuffer-history-initialize ()
  (setq minibuffer-text-before-history nil))

720 721 722 723
(defun minibuffer-avoid-prompt (new old)
  "A point-motion hook for the minibuffer, that moves point out of the prompt."
  (constrain-to-field nil (point-max)))

724 725 726 727 728 729 730 731
(defcustom minibuffer-history-case-insensitive-variables nil
  "*Minibuffer history variables for which matching should ignore case.
If a history variable is a member of this list, then the
\\[previous-matching-history-element] and \\[next-matching-history-element]\
 commands ignore case when searching it, regardless of `case-fold-search'."
  :type '(repeat variable)
  :group 'minibuffer)

732
(defun previous-matching-history-element (regexp n)
733 734 735
  "Find the previous history element that matches REGEXP.
\(Previous history elements refer to earlier actions.)
With prefix argument N, search for Nth previous match.
736
If N is negative, find the next or Nth next match.
737 738 739
Normally, history elements are matched case-insensitively if
`case-fold-search' is non-nil, but an uppercase letter in REGEXP
makes the search case-sensitive.
740
See also `minibuffer-history-case-insensitive-variables'."
741
  (interactive
742 743 744 745 746 747 748 749
   (let* ((enable-recursive-minibuffers t)
	  (regexp (read-from-minibuffer "Previous element matching (regexp): "
					nil
					minibuffer-local-map
					nil
					'minibuffer-history-search-history)))
     ;; Use the last regexp specified, by default, if input is empty.
     (list (if (string= regexp "")
750 751 752
	       (if minibuffer-history-search-history
		   (car minibuffer-history-search-history)
		 (error "No previous history search regexp"))
753
	     regexp)
754
	   (prefix-numeric-value current-prefix-arg))))
755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776
  (unless (zerop n)
    (if (and (zerop minibuffer-history-position)
	     (null minibuffer-text-before-history))
	(setq minibuffer-text-before-history (field-string (point-max))))
    (let ((history (symbol-value minibuffer-history-variable))
	  (case-fold-search
	   (if (isearch-no-upper-case-p regexp t) ; assume isearch.el is dumped
	       ;; On some systems, ignore case for file names.
	       (if (memq minibuffer-history-variable
			 minibuffer-history-case-insensitive-variables)
		   t
		 ;; Respect the user's setting for case-fold-search:
		 case-fold-search)
	     nil))
	  prevpos
	  match-string
	  match-offset
	  (pos minibuffer-history-position))
      (while (/= n 0)
	(setq prevpos pos)
	(setq pos (min (max 1 (+ pos (if (< n 0) -1 1))) (length history)))
	(when (= pos prevpos)
777
	  (error (if (= pos 1)
778 779
		     "No later matching history item"
		   "No earlier matching history item")))
780 781
	(setq match-string
	      (if (eq minibuffer-history-sexp-flag (minibuffer-depth))
782
		  (let ((print-level nil))
783 784 785 786 787 788 789 790 791 792 793 794 795 796 797
		    (prin1-to-string (nth (1- pos) history)))
		(nth (1- pos) history)))
	(setq match-offset
	      (if (< n 0)
		  (and (string-match regexp match-string)
		       (match-end 0))
		(and (string-match (concat ".*\\(" regexp "\\)") match-string)
		     (match-beginning 1))))
	(when match-offset
	  (setq n (+ n (if (< n 0) 1 -1)))))
      (setq minibuffer-history-position pos)
      (goto-char (point-max))
      (delete-field)
      (insert match-string)
      (goto-char (+ (field-beginning) match-offset))))
798 799 800
  (if (or (eq (car (car command-history)) 'previous-matching-history-element)
	  (eq (car (car command-history)) 'next-matching-history-element))
      (setq command-history (cdr command-history))))
801 802

(defun next-matching-history-element (regexp n)
803 804 805
  "Find the next history element that matches REGEXP.
\(The next history element refers to a more recent action.)
With prefix argument N, search for Nth next match.
806
If N is negative, find the previous or Nth previous match.
807 808 809
Normally, history elements are matched case-insensitively if
`case-fold-search' is non-nil, but an uppercase letter in REGEXP
makes the search case-sensitive."
810
  (interactive
811 812 813 814 815 816 817 818 819 820 821
   (let* ((enable-recursive-minibuffers t)
	  (regexp (read-from-minibuffer "Next element matching (regexp): "
					nil
					minibuffer-local-map
					nil
					'minibuffer-history-search-history)))
     ;; Use the last regexp specified, by default, if input is empty.
     (list (if (string= regexp "")
	       (setcar minibuffer-history-search-history
		       (nth 1 minibuffer-history-search-history))
	     regexp)
822
	   (prefix-numeric-value current-prefix-arg))))
823
  (previous-matching-history-element regexp (- n)))
Jim Blandy's avatar
Jim Blandy committed
824

825 826
(defvar minibuffer-temporary-goal-position nil)

827 828
(defun next-history-element (n)
  "Insert the next element of the minibuffer history into the minibuffer."
Jim Blandy's avatar
Jim Blandy committed
829
  (interactive "p")
830
  (or (zerop n)
831 832
      (let ((narg (- minibuffer-history-position n))
	    (minimum (if minibuffer-default -1 0))
Karl Heuer's avatar
Karl Heuer committed
833
	    elt minibuffer-returned-to-present)
834 835
	(if (and (zerop minibuffer-history-position)
		 (null minibuffer-text-before-history))
Gerd Moellmann's avatar
Gerd Moellmann committed
836
	    (setq minibuffer-text-before-history (field-string (point-max))))
837
	(if (< narg minimum)
838 839 840
	    (if minibuffer-default
		(error "End of history; no next item")
	      (error "End of history; no default available")))
841 842
	(if (> narg (length (symbol-value minibuffer-history-variable)))
	    (error "Beginning of history; no preceding item"))
843 844 845 846 847 848 849
	(unless (or (eq last-command 'next-history-element)
		    (eq last-command 'previous-history-element))
	  (let ((prompt-end (field-beginning (point-max))))
	    (set (make-local-variable 'minibuffer-temporary-goal-position)
		 (cond ((<= (point) prompt-end) prompt-end)
		       ((eobp) nil)
		       (t (point))))))
Gerd Moellmann's avatar
Gerd Moellmann committed
850
	(goto-char (point-max))
851
	(delete-field)
852 853 854 855
	(setq minibuffer-history-position narg)
	(cond ((= narg -1)
	       (setq elt minibuffer-default))
	      ((= narg 0)
Richard M. Stallman's avatar
Richard M. Stallman committed
856
	       (setq elt (or minibuffer-text-before-history ""))
Karl Heuer's avatar
Karl Heuer committed
857
	       (setq minibuffer-returned-to-present t)
858 859 860 861
	       (setq minibuffer-text-before-history nil))
	      (t (setq elt (nth (1- minibuffer-history-position)
				(symbol-value minibuffer-history-variable)))))
	(insert
Karl Heuer's avatar
Karl Heuer committed
862 863
	 (if (and (eq minibuffer-history-sexp-flag (minibuffer-depth))
		  (not minibuffer-returned-to-present))
864 865 866
	     (let ((print-level nil))
	       (prin1-to-string elt))
	   elt))
867
	(goto-char (or minibuffer-temporary-goal-position (point-max))))))
Jim Blandy's avatar
Jim Blandy committed
868

869
(defun previous-history-element (n)
Richard M. Stallman's avatar
Richard M. Stallman committed
870
  "Inserts the previous element of the minibuffer history into the minibuffer."
Jim Blandy's avatar
Jim Blandy committed
871
  (interactive "p")
872
  (next-history-element (- n)))
873 874

(defun next-complete-history-element (n)
Gerd Moellmann's avatar
Gerd Moellmann committed
875 876 877
  "Get next history element which completes the minibuffer before the point.
The contents of the minibuffer after the point are deleted, and replaced
by the new completion."
878
  (interactive "p")
879 880
  (let ((point-at-start (point)))
    (next-matching-history-element
Gerd Moellmann's avatar
Gerd Moellmann committed
881 882 883
     (concat
      "^" (regexp-quote (buffer-substring (field-beginning) (point))))
     n)
884 885 886 887
    ;; next-matching-history-element always puts us at (point-min).
    ;; Move to the position we were at before changing the buffer contents.
    ;; This is still sensical, because the text before point has not changed.
    (goto-char point-at-start)))
888 889

(defun previous-complete-history-element (n)
890
  "\
Gerd Moellmann's avatar
Gerd Moellmann committed
891 892 893
Get previous history element which completes the minibuffer before the point.
The contents of the minibuffer after the point are deleted, and replaced
by the new completion."
894 895
  (interactive "p")
  (next-complete-history-element (- n)))
Gerd Moellmann's avatar
Gerd Moellmann committed
896 897 898 899 900 901 902 903 904 905 906 907 908

;; These two functions are for compatibility with the old subrs of the
;; same name.

(defun minibuffer-prompt-width ()
  "Return the display width of the minibuffer prompt.
Return 0 if current buffer is not a mini-buffer."
  ;; Return the width of everything before the field at the end of
  ;; the buffer; this should be 0 for normal buffers.
  (1- (field-beginning (point-max))))

(defun minibuffer-prompt-end ()
  "Return the buffer position of the end of the minibuffer prompt.
909
Return (point-min) if current buffer is not a mini-buffer."
910 911
  (field-beginning (point-max)))

912 913 914 915 916 917 918 919 920 921 922 923 924 925
(defun minibuffer-contents ()
  "Return the user input in a minbuffer as a string.
The current buffer must be a minibuffer."
  (field-string (point-max)))

(defun minibuffer-contents-no-properties ()
  "Return the user input in a minbuffer as a string, without text-properties.
The current buffer must be a minibuffer."
  (field-string-no-properties (point-max)))

(defun delete-minibuffer-contents  ()
  "Delete all user input in a minibuffer.
The current buffer must be a minibuffer."
  (delete-field (point-max)))
926

Jim Blandy's avatar
Jim Blandy committed
927
;Put this on C-x u, so we can force that rather than C-_ into startup msg
928
(defalias 'advertised-undo 'undo)
Jim Blandy's avatar
Jim Blandy committed
929 930 931 932

(defun undo (&optional arg)
  "Undo some previous changes.
Repeat this command to undo more changes.
933 934
A numeric argument serves as a repeat count.

935 936 937
In Transient Mark mode when the mark is active, only undo changes within
the current region.  Similarly, when not in Transient Mark mode, just C-u
as an argument limits undo to changes within the current region."
938
  (interactive "*P")
939 940 941
  ;; If we don't get all the way thru, make last-command indicate that
  ;; for the following command.
  (setq this-command t)
942 943
  (let ((modified (buffer-modified-p))
	(recent-save (recent-auto-save-p)))
Jim Blandy's avatar
Jim Blandy committed
944 945
    (or (eq (selected-window) (minibuffer-window))
	(message "Undo!"))
946 947 948 949 950 951 952 953 954 955
    (unless (eq last-command 'undo)
      (if (if transient-mark-mode mark-active (and arg (not (numberp arg))))
	  (undo-start (region-beginning) (region-end))
	(undo-start))
      ;; get rid of initial undo boundary
      (undo-more 1))
    (undo-more
     (if (or transient-mark-mode (numberp arg))
	 (prefix-numeric-value arg)
       1))
956 957 958 959 960 961 962 963 964 965
    ;; Don't specify a position in the undo record for the undo command.
    ;; Instead, undoing this should move point to where the change is.
    (let ((tail buffer-undo-list)
	  done)
      (while (and tail (not done) (not (null (car tail))))
	(if (integerp (car tail))
	    (progn
	      (setq done t)
	      (setq buffer-undo-list (delq (car tail) buffer-undo-list))))
	(setq tail (cdr tail))))
Jim Blandy's avatar
Jim Blandy committed
966
    (and modified (not (buffer-modified-p))
967 968 969
	 (delete-auto-save-file-if-necessary recent-save)))
  ;; If we do get all the way thru, make this-command indicate that.
  (setq this-command 'undo))
Jim Blandy's avatar
Jim Blandy committed
970

971 972 973
(defvar pending-undo-list nil
  "Within a run of consecutive undo commands, list remaining to be undone.")

974 975 976 977
(defvar undo-in-progress nil
  "Non-nil while performing an undo.
Some change-hooks test this variable to do something different.")

Jim Blandy's avatar
Jim Blandy committed
978 979
(defun undo-more (count)
  "Undo back N undo-boundaries beyond what was already undone recently.
980 981
Call `undo-start' to get ready to undo recent changes,
then call `undo-more' one or more times to undo them."
Jim Blandy's avatar
Jim Blandy committed
982 983
  (or pending-undo-list
      (error "No further undo information"))
984 985
  (let ((undo-in-progress t))
    (setq pending-undo-list (primitive-undo count pending-undo-list))))
Jim Blandy's avatar
Jim Blandy committed
986

987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004
;; Deep copy of a list
(defun undo-copy-list (list)
  "Make a copy of undo list LIST."
  (mapcar 'undo-copy-list-1 list))

(defun undo-copy-list-1 (elt)
  (if (consp elt)
      (cons (car elt) (undo-copy-list-1 (cdr elt)))
    elt))

(defun undo-start (&optional beg end)
  "Set `pending-undo-list' to the front of the undo list.
The next call to `undo-more' will undo the most recently made change.
If BEG and END are specified, then only undo elements
that apply to text between BEG and END are used; other undo elements
are ignored.  If BEG and END are nil, all undo elements are used."
  (if (eq buffer-undo-list t)
      (error "No undo information in this buffer"))
1005
  (setq pending-undo-list
1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065
	(if (and beg end (not (= beg end)))
	    (undo-make-selective-list (min beg end) (max beg end))
	  buffer-undo-list)))

(defvar undo-adjusted-markers)

(defun undo-make-selective-list (start end)
  "Return a list of undo elements for the region START to END.
The elements come from `buffer-undo-list', but we keep only
the elements inside this region, and discard those outside this region.
If we find an element that crosses an edge of this region,
we stop and ignore all further elements."
  (let ((undo-list-copy (undo-copy-list buffer-undo-list))
	(undo-list (list nil))
	undo-adjusted-markers
	some-rejected
	undo-elt undo-elt temp-undo-list delta)
    (while undo-list-copy
      (setq undo-elt (car undo-list-copy))
      (let ((keep-this
	     (cond ((and (consp undo-elt) (eq (car undo-elt) t))
		    ;; This is a "was unmodified" element.
		    ;; Keep it if we have kept everything thus far.
		    (not some-rejected))
		   (t
		    (undo-elt-in-region undo-elt start end)))))
	(if keep-this
	    (progn
	      (setq end (+ end (cdr (undo-delta undo-elt))))
	      ;; Don't put two nils together in the list
	      (if (not (and (eq (car undo-list) nil)
			    (eq undo-elt nil)))
		  (setq undo-list (cons undo-elt undo-list))))
	  (if (undo-elt-crosses-region undo-elt start end)
	      (setq undo-list-copy nil)
	    (setq some-rejected t)
	    (setq temp-undo-list (cdr undo-list-copy))
	    (setq delta (undo-delta undo-elt))

	    (when (/= (cdr delta) 0)
	      (let ((position (car delta))