1 /* Indentation functions.
2 Copyright (C) 1985, 1986, 1987, 1988, 1993 Free Software Foundation, Inc.
4 This file is part of GNU Emacs.
6 GNU Emacs is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 1, or (at your option)
11 GNU Emacs is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU Emacs; see the file COPYING. If not, write to
18 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
30 #include "intervals.h"
32 /* Indentation can insert tabs if this is non-zero;
33 otherwise always uses spaces */
36 #define min(a, b) ((a) < (b) ? (a) : (b))
37 #define max(a, b) ((a) > (b) ? (a) : (b))
41 /* These three values memoize the current column to avoid recalculation */
42 /* Some things in set last_known_column_point to -1
43 to mark the memoized value as invalid */
44 /* Last value returned by current_column */
45 int last_known_column
;
46 /* Value of point when current_column was called */
47 int last_known_column_point
;
48 /* Value of MODIFF when current_column was called */
49 int last_known_column_modified
;
51 /* Get the display table to use for the current buffer. */
54 buffer_display_table ()
58 thisbuf
= current_buffer
->display_table
;
59 if (XTYPE (thisbuf
) == Lisp_Vector
60 && XVECTOR (thisbuf
)->size
== DISP_TABLE_SIZE
)
61 return XVECTOR (thisbuf
);
62 if (XTYPE (Vstandard_display_table
) == Lisp_Vector
63 && XVECTOR (Vstandard_display_table
)->size
== DISP_TABLE_SIZE
)
64 return XVECTOR (Vstandard_display_table
);
68 DEFUN ("current-column", Fcurrent_column
, Scurrent_column
, 0, 0, 0,
69 "Return the horizontal position of point. Beginning of line is column 0.\n\
70 This is calculated by adding together the widths of all the displayed\n\
71 representations of the character between the start of the previous line\n\
72 and point. (eg control characters will have a width of 2 or 4, tabs\n\
73 will have a variable width)\n\
74 Ignores finite width of frame, which means that this function may return\n\
75 values greater than (frame-width).\n\
76 Whether the line is visible (if `selective-display' is t) has no effect;\n\
77 however, ^M is treated as end of line when `selective-display' is t.")
81 XFASTINT (temp
) = current_column ();
85 /* Cancel any recorded value of the horizontal position. */
87 invalidate_current_column ()
89 last_known_column_point
= 0;
96 register unsigned char *ptr
, *stop
;
97 register int tab_seen
;
100 register int tab_width
= XINT (current_buffer
->tab_width
);
101 int ctl_arrow
= !NILP (current_buffer
->ctl_arrow
);
102 register struct Lisp_Vector
*dp
= buffer_display_table ();
105 if (point
== last_known_column_point
106 && MODIFF
== last_known_column_modified
)
107 return last_known_column
;
109 /* Make a pointer for decrementing through the chars before point. */
110 ptr
= &FETCH_CHAR (point
- 1) + 1;
111 /* Make a pointer to where consecutive chars leave off,
112 going backwards from point. */
115 else if (point
<= GPT
|| BEGV
> GPT
)
120 if (tab_width
<= 0 || tab_width
> 1000) tab_width
= 8;
122 col
= 0, tab_seen
= 0, post_tab
= 0;
128 /* We stopped either for the beginning of the buffer
130 if (ptr
== BEGV_ADDR
)
132 /* It was the gap. Jump back over it. */
135 /* Check whether that brings us to beginning of buffer. */
136 if (BEGV
>= GPT
) break;
140 if (c
>= 040 && c
< 0177
141 && (dp
== 0 || XTYPE (DISP_CHAR_VECTOR (dp
, c
)) != Lisp_Vector
))
147 else if (c
== '\r' && EQ (current_buffer
->selective_display
, Qt
))
152 col
= ((col
+ tab_width
) / tab_width
) * tab_width
;
158 else if (dp
!= 0 && XTYPE (DISP_CHAR_VECTOR (dp
, c
)) == Lisp_Vector
)
159 col
+= XVECTOR (DISP_CHAR_VECTOR (dp
, c
))->size
;
161 col
+= (ctl_arrow
&& c
< 0200) ? 2 : 4;
166 col
= ((col
+ tab_width
) / tab_width
) * tab_width
;
170 last_known_column
= col
;
171 last_known_column_point
= point
;
172 last_known_column_modified
= MODIFF
;
178 DEFUN ("indent-to", Findent_to
, Sindent_to
, 1, 2, "NIndent to column: ",
179 "Indent from point with tabs and spaces until COLUMN is reached.\n\
180 Optional second argument MIN says always do at least MIN spaces\n\
181 even if that goes past COLUMN; by default, MIN is zero.")
183 Lisp_Object col
, minimum
;
186 register int fromcol
;
187 register int tab_width
= XINT (current_buffer
->tab_width
);
189 CHECK_NUMBER (col
, 0);
191 XFASTINT (minimum
) = 0;
192 CHECK_NUMBER (minimum
, 1);
194 fromcol
= current_column ();
195 mincol
= fromcol
+ XINT (minimum
);
196 if (mincol
< XINT (col
)) mincol
= XINT (col
);
198 if (fromcol
== mincol
)
199 return make_number (mincol
);
201 if (tab_width
<= 0 || tab_width
> 1000) tab_width
= 8;
203 if (indent_tabs_mode
)
206 XFASTINT (n
) = mincol
/ tab_width
- fromcol
/ tab_width
;
207 if (XFASTINT (n
) != 0)
209 Finsert_char (make_number ('\t'), n
);
211 fromcol
= (mincol
/ tab_width
) * tab_width
;
215 XFASTINT (col
) = mincol
- fromcol
;
216 Finsert_char (make_number (' '), col
);
218 last_known_column
= mincol
;
219 last_known_column_point
= point
;
220 last_known_column_modified
= MODIFF
;
222 XSETINT (col
, mincol
);
226 DEFUN ("current-indentation", Fcurrent_indentation
, Scurrent_indentation
,
228 "Return the indentation of the current line.\n\
229 This is the horizontal position of the character\n\
230 following any initial whitespace.")
235 XFASTINT (val
) = position_indentation (find_next_newline (point
, -1));
239 position_indentation (pos
)
242 register int column
= 0;
243 register int tab_width
= XINT (current_buffer
->tab_width
);
244 register unsigned char *p
;
245 register unsigned char *stop
;
247 if (tab_width
<= 0 || tab_width
> 1000) tab_width
= 8;
249 stop
= &FETCH_CHAR (BUFFER_CEILING_OF (pos
)) + 1;
250 p
= &FETCH_CHAR (pos
);
257 pos
+= p
- &FETCH_CHAR (pos
);
258 p
= &FETCH_CHAR (pos
);
259 stop
= &FETCH_CHAR (BUFFER_CEILING_OF (pos
)) + 1;
267 column
+= tab_width
- column
% tab_width
;
275 /* Test whether the line beginning at POS is indented beyond COLUMN.
276 Blank lines are treated as if they had the same indentation as the
279 indented_beyond_p (pos
, column
)
282 while (pos
> BEGV
&& FETCH_CHAR (pos
) == '\n')
283 pos
= find_next_newline (pos
- 1, -1);
284 return (position_indentation (pos
) >= column
);
287 DEFUN ("move-to-column", Fmove_to_column
, Smove_to_column
, 1, 2, 0,
288 "Move point to column COLUMN in the current line.\n\
289 The column of a character is calculated by adding together the widths\n\
290 as displayed of the previous characters in the line.\n\
291 This function ignores line-continuation;\n\
292 there is no upper limit on the column number a character can have\n\
293 and horizontal scrolling has no effect.\n\
295 If specified column is within a character, point goes after that character.\n\
296 If it's past end of line, point goes to end of line.\n\n\
297 A non-nil second (optional) argument FORCE means, if the line\n\
298 is too short to reach column COLUMN then add spaces/tabs to get there,\n\
299 and if COLUMN is in the middle of a tab character, change it to spaces.")
301 Lisp_Object column
, force
;
304 register int col
= current_column ();
307 register int tab_width
= XINT (current_buffer
->tab_width
);
308 register int ctl_arrow
= !NILP (current_buffer
->ctl_arrow
);
309 register struct Lisp_Vector
*dp
= buffer_display_table ();
315 if (tab_width
<= 0 || tab_width
> 1000) tab_width
= 8;
316 CHECK_NATNUM (column
, 0);
317 goal
= XINT (column
);
323 /* If we're starting past the desired column,
324 back up to beginning of line and scan from there. */
327 pos
= find_next_newline (pos
, -1);
331 while (col
< goal
&& pos
< end
)
333 c
= FETCH_CHAR (pos
);
336 if (c
== '\r' && EQ (current_buffer
->selective_display
, Qt
))
343 col
= col
/ tab_width
* tab_width
;
345 else if (dp
!= 0 && XTYPE (DISP_CHAR_VECTOR (dp
, c
)) == Lisp_Vector
)
346 col
+= XVECTOR (DISP_CHAR_VECTOR (dp
, c
))->size
;
347 else if (ctl_arrow
&& (c
< 040 || c
== 0177))
349 else if (c
< 040 || c
>= 0177)
357 /* If a tab char made us overshoot, change it to spaces
358 and scan through it again. */
359 if (!NILP (force
) && col
> goal
&& c
== '\t' && prev_col
< goal
)
363 del_range (point
- 1, point
);
364 Findent_to (make_number (goal
), Qnil
);
366 Findent_to (make_number (col
), Qnil
);
368 /* Set the last_known... vars consistently. */
372 /* If line ends prematurely, add space to the end. */
373 if (col
< goal
&& !NILP (force
))
374 Findent_to (make_number (col
= goal
), Qnil
);
376 last_known_column
= col
;
377 last_known_column_point
= point
;
378 last_known_column_modified
= MODIFF
;
380 XFASTINT (val
) = col
;
384 struct position val_compute_motion
;
386 /* Scan the current buffer forward from offset FROM, pretending that
387 this is at line FROMVPOS, column FROMHPOS, until reaching buffer
388 offset TO or line TOVPOS, column TOHPOS (whichever comes first),
389 and return the ending buffer position and screen location.
391 WIDTH is the number of columns available to display text;
392 compute_motion uses this to handle continuation lines and such.
393 HSCROLL is the number of columns not being displayed at the left
394 margin; this is usually taken from a window's hscroll member.
395 TAB_OFFSET is the number of columns of the first tab that aren't
396 being displayed, perhaps because of a continuation line or
399 compute_motion returns a pointer to a struct position. The bufpos
400 member gives the buffer position at the end of the scan, and hpos
401 and vpos give its cartesian location. I'm not clear on what the
404 Note that FROMHPOS and TOHPOS should be expressed in real screen
405 columns, taking HSCROLL and the truncation glyph at the left margin
406 into account. That is, beginning-of-line moves you to the hpos
407 -HSCROLL + (HSCROLL > 0).
409 For example, to find the buffer position of column COL of line LINE
410 of a certain window, pass the window's starting location as FROM
411 and the window's upper-left coordinates as FROMVPOS and FROMHPOS.
412 Pass the buffer's ZV as TO, to limit the scan to the end of the
413 visible section of the buffer, and pass LINE and COL as TOVPOS and
416 When displaying in window w, a typical formula for WIDTH is:
419 - (has_vertical_scroll_bars
420 ? VERTICAL_SCROLL_BAR_WIDTH
421 : (window_width + window_left != frame_width))
424 window_width is XFASTINT (w->width),
425 window_left is XFASTINT (w->left),
426 has_vertical_scroll_bars is
427 FRAME_HAS_VERTICAL_SCROLL_BARS (XFRAME (WINDOW_FRAME (window)))
428 and frame_width = FRAME_WIDTH (XFRAME (window->frame))
430 Or you can let window_internal_width do this all for you, and write:
431 window_internal_width (w) - 1
433 The `-1' accounts for the continuation-line backslashes; the rest
434 accounts for window borders if the window is split horizontally, and
435 the scroll bars if they are turned on. */
438 compute_motion (from
, fromvpos
, fromhpos
, to
, tovpos
, tohpos
, width
, hscroll
, tab_offset
)
439 int from
, fromvpos
, fromhpos
, to
, tovpos
, tohpos
;
441 int hscroll
, tab_offset
;
443 register int hpos
= fromhpos
;
444 register int vpos
= fromvpos
;
448 register int tab_width
= XFASTINT (current_buffer
->tab_width
);
449 register int ctl_arrow
= !NILP (current_buffer
->ctl_arrow
);
450 register struct Lisp_Vector
*dp
= buffer_display_table ();
452 = XTYPE (current_buffer
->selective_display
) == Lisp_Int
453 ? XINT (current_buffer
->selective_display
)
454 : !NILP (current_buffer
->selective_display
) ? -1 : 0;
455 int prev_vpos
, prev_hpos
= 0;
457 = (selective
&& dp
&& XTYPE (DISP_INVIS_VECTOR (dp
)) == Lisp_Vector
458 ? XVECTOR (DISP_INVIS_VECTOR (dp
))->size
: 0);
459 #ifdef USE_TEXT_PROPERTIES
460 /* The next location where the `invisible' property changes */
461 int next_invisible
= from
;
462 Lisp_Object prop
, position
;
465 if (tab_width
<= 0 || tab_width
> 1000) tab_width
= 8;
466 for (pos
= from
; pos
< to
; pos
++)
468 /* Stop if past the target screen position. */
470 || (vpos
== tovpos
&& hpos
>= tohpos
))
476 #ifdef USE_TEXT_PROPERTIES
477 /* if the `invisible' property is set, we can skip to
478 the next property change */
479 while (pos
== next_invisible
&& pos
< to
)
481 XFASTINT (position
) = pos
;
482 prop
= Fget_char_property (position
,
486 Lisp_Object end
, limit
;
488 /* This is just an estimate to give reasonable
489 performance; nothing should go wrong if it is too small. */
490 limit
= Fnext_overlay_change (position
);
491 if (XFASTINT (limit
) > pos
+ 100)
492 XFASTINT (limit
) = pos
+ 100;
493 end
= Fnext_single_property_change (position
, Qinvisible
,
494 Fcurrent_buffer (), limit
);
496 next_invisible
= XINT (end
);
500 pos
= next_invisible
;
506 c
= FETCH_CHAR (pos
);
507 if (c
>= 040 && c
< 0177
508 && (dp
== 0 || XTYPE (DISP_CHAR_VECTOR (dp
, c
)) != Lisp_Vector
))
512 hpos
+= tab_width
- ((hpos
+ tab_offset
+ hscroll
- (hscroll
> 0)
513 /* Add tab_width here to make sure positive.
514 hpos can be negative after continuation
515 but can't be less than -tab_width. */
521 if (selective
> 0 && indented_beyond_p (pos
+ 1, selective
))
523 /* Skip any number of invisible lines all at once */
526 while (++pos
< to
&& FETCH_CHAR (pos
) != '\n');
528 while (pos
< to
&& indented_beyond_p (pos
+ 1, selective
));
529 pos
--; /* Reread the newline on the next pass. */
530 /* Allow for the " ..." that is displayed for them. */
533 hpos
+= selective_rlen
;
537 /* We have skipped the invis text, but not the newline after. */
541 /* A visible line. */
545 if (hscroll
> 0) hpos
++; /* Truncation glyph on column 0 */
549 else if (c
== CR
&& selective
< 0)
551 /* In selective display mode,
552 everything from a ^M to the end of the line is invisible */
553 while (pos
< to
&& FETCH_CHAR (pos
) != '\n') pos
++;
554 /* Stop *before* the real newline. */
556 /* Allow for the " ..." that is displayed for them. */
559 hpos
+= selective_rlen
;
564 else if (dp
!= 0 && XTYPE (DISP_CHAR_VECTOR (dp
, c
)) == Lisp_Vector
)
565 hpos
+= XVECTOR (DISP_CHAR_VECTOR (dp
, c
))->size
;
567 hpos
+= (ctl_arrow
&& c
< 0200) ? 2 : 4;
569 /* Handle right margin. */
573 && FETCH_CHAR (pos
+ 1) != '\n')))
576 || (vpos
== tovpos
&& hpos
>= tohpos
))
579 || (truncate_partial_width_windows
580 && width
+ 1 < FRAME_WIDTH (selected_frame
))
581 || !NILP (current_buffer
->truncate_lines
))
583 /* Truncating: skip to newline. */
584 while (pos
< to
&& FETCH_CHAR (pos
) != '\n') pos
++;
599 val_compute_motion
.bufpos
= pos
;
600 val_compute_motion
.hpos
= hpos
;
601 val_compute_motion
.vpos
= vpos
;
602 val_compute_motion
.prevhpos
= prev_hpos
;
604 /* Nonzero if have just continued a line */
605 val_compute_motion
.contin
607 && (val_compute_motion
.vpos
!= prev_vpos
)
610 return &val_compute_motion
;
613 #if 0 /* The doc string is too long for some compilers,
614 but make-docfile can find it in this comment. */
615 DEFUN ("compute-motion", Ffoo
, Sfoo
, 6, 6, 0,
616 "Scan through the current buffer, calculating screen position.\n\
617 Scan the current buffer forward from offset FROM,\n\
618 assuming it is at position FROMPOS--a cons of the form (HPOS . VPOS)--\n\
619 to position TO or position TOPOS--another cons of the form (HPOS . VPOS)--\n\
620 and return the ending buffer position and screen location.\n\
622 There are two additional arguments:\n\
624 WIDTH is the number of columns available to display text;\n\
625 this affects handling of continuation lines.\n\
626 This is usually the value returned by `window-width', less one (to allow\n\
627 for the continuation glyph).\n\
629 OFFSETS is either nil or a cons cell (HSCROLL . TAB-OFFSET).\n\
630 HSCROLL is the number of columns not being displayed at the left\n\
631 margin; this is usually taken from a window's hscroll member.\n\
632 TAB-OFFSET is the number of columns of the first tab that aren't\n\
633 being displayed, perhaps because the line was continued within it.\n\
634 If OFFSETS is nil, HSCROLL and TAB-OFFSET are assumed to be zero.\n\
636 The value is a list of five elements:\n\
637 (POS HPOS VPOS PREVHPOS CONTIN)\n\
638 POS is the buffer position where the scan stopped.\n\
639 VPOS is the vertical position where the scan stopped.\n\
640 HPOS is the horizontal position where the scan stopped.\n\
642 PREVHPOS is the horizontal position one character back from POS.\n\
643 CONTIN is t if a line was continued after (or within) the previous character.\n\
645 For example, to find the buffer position of column COL of line LINE\n\
646 of a certain window, pass the window's starting location as FROM\n\
647 and the window's upper-left coordinates as FROMPOS.\n\
648 Pass the buffer's (point-max) as TO, to limit the scan to the end of the\n\
649 visible section of the buffer, and pass LINE and COL as TOPOS.")
652 DEFUN ("compute-motion", Ffoo
, Sfoo
, 6, 6, 0,
654 (from
, frompos
, to
, topos
, width
, offsets
)
655 Lisp_Object from
, frompos
, to
, topos
;
656 Lisp_Object width
, offsets
;
658 Lisp_Object bufpos
, hpos
, vpos
, prevhpos
, contin
;
659 struct position
*pos
;
660 int hscroll
, tab_offset
;
662 CHECK_NUMBER_COERCE_MARKER (from
, 0);
663 CHECK_CONS (frompos
, 0);
664 CHECK_NUMBER (XCONS (frompos
)->car
, 0);
665 CHECK_NUMBER (XCONS (frompos
)->cdr
, 0);
666 CHECK_NUMBER_COERCE_MARKER (to
, 0);
667 CHECK_CONS (topos
, 0);
668 CHECK_NUMBER (XCONS (topos
)->car
, 0);
669 CHECK_NUMBER (XCONS (topos
)->cdr
, 0);
670 CHECK_NUMBER (width
, 0);
673 CHECK_CONS (offsets
, 0);
674 CHECK_NUMBER (XCONS (offsets
)->car
, 0);
675 CHECK_NUMBER (XCONS (offsets
)->cdr
, 0);
676 hscroll
= XINT (XCONS (offsets
)->car
);
677 tab_offset
= XINT (XCONS (offsets
)->cdr
);
680 hscroll
= tab_offset
= 0;
682 pos
= compute_motion (XINT (from
), XINT (XCONS (frompos
)->cdr
),
683 XINT (XCONS (frompos
)->car
),
684 XINT (to
), XINT (XCONS (topos
)->cdr
),
685 XINT (XCONS (topos
)->car
),
686 XINT (width
), hscroll
, tab_offset
);
688 XFASTINT (bufpos
) = pos
->bufpos
;
689 XSET (hpos
, Lisp_Int
, pos
->hpos
);
690 XSET (vpos
, Lisp_Int
, pos
->vpos
);
691 XSET (prevhpos
, Lisp_Int
, pos
->prevhpos
);
693 return Fcons (bufpos
,
697 Fcons (pos
->contin
? Qt
: Qnil
, Qnil
)))));
701 /* Return the column of position POS in window W's buffer,
702 rounded down to a multiple of the internal width of W.
703 This is the amount of indentation of position POS
704 that is not visible in its horizontal position in the window. */
707 pos_tab_offset (w
, pos
)
713 int width
= window_internal_width (w
) - 1;
715 if (pos
== BEGV
|| FETCH_CHAR (pos
- 1) == '\n')
718 col
= current_column ();
720 return col
- (col
% width
);
723 /* start_hpos is the hpos of the first character of the buffer:
724 zero except for the minibuffer window,
725 where it is the width of the prompt. */
727 struct position val_vmotion
;
730 vmotion (from
, vtarget
, width
, hscroll
, window
)
731 register int from
, vtarget
, width
;
736 /* vpos is cumulative vertical position, changed as from is changed */
737 register int vpos
= 0;
738 register int prevline
;
740 int lmargin
= hscroll
> 0 ? 1 - hscroll
: 0;
742 = XTYPE (current_buffer
->selective_display
) == Lisp_Int
743 ? XINT (current_buffer
->selective_display
)
744 : !NILP (current_buffer
->selective_display
) ? -1 : 0;
745 int start_hpos
= (EQ (window
, minibuf_window
) ? minibuf_prompt_width
: 0);
750 /* Moving downward is simple, but must calculate from beg of line
751 to determine hpos of starting point */
752 if (from
> BEGV
&& FETCH_CHAR (from
- 1) != '\n')
754 prevline
= find_next_newline (from
, -1);
755 while (prevline
> BEGV
757 && indented_beyond_p (prevline
, selective
))
758 #ifdef USE_TEXT_PROPERTIES
759 /* watch out for newlines with `invisible' property */
760 || ! NILP (Fget_char_property (XFASTINT (prevline
),
765 prevline
= find_next_newline (prevline
- 1, -1);
766 pos
= *compute_motion (prevline
, 0,
767 lmargin
+ (prevline
== 1 ? start_hpos
: 0),
768 from
, 1 << (INTBITS
- 2), 0,
773 pos
.hpos
= lmargin
+ (from
== 1 ? start_hpos
: 0);
776 return compute_motion (from
, vpos
, pos
.hpos
,
777 ZV
, vtarget
, - (1 << (INTBITS
- 2)),
778 width
, hscroll
, pos
.vpos
* width
);
781 /* To move upward, go a line at a time until
782 we have gone at least far enough */
786 while ((vpos
> vtarget
|| first
) && from
> BEGV
)
791 prevline
= find_next_newline (prevline
- 1, -1);
794 || ! indented_beyond_p (prevline
, selective
))
795 #ifdef USE_TEXT_PROPERTIES
796 /* watch out for newlines with `invisible' property */
797 && NILP (Fget_char_property (XFASTINT (prevline
),
804 pos
= *compute_motion (prevline
, 0,
805 lmargin
+ (prevline
== 1 ? start_hpos
: 0),
806 from
, 1 << (INTBITS
- 2), 0,
813 /* If we made exactly the desired vertical distance,
814 or if we hit beginning of buffer,
815 return point found */
818 val_vmotion
.bufpos
= from
;
819 val_vmotion
.vpos
= vpos
;
820 val_vmotion
.hpos
= lmargin
;
821 val_vmotion
.contin
= 0;
822 val_vmotion
.prevhpos
= 0;
826 /* Otherwise find the correct spot by moving down */
830 DEFUN ("vertical-motion", Fvertical_motion
, Svertical_motion
, 1, 2, 0,
831 "Move to start of screen line LINES lines down.\n\
832 If LINES is negative, this is moving up.\n\
833 The optional second argument WINDOW specifies the window\n\
834 to use for computations.\n\
835 Sets point to position found; this may be start of line\n\
836 or just the start of a continuation line.\n\
837 Returns number of lines moved; may be closer to zero than LINES\n\
838 if beginning or end of buffer was reached.")
840 Lisp_Object lines
, window
;
843 register struct window
*w
= XWINDOW (selected_window
);
844 int width
= window_internal_width (w
) - 1;
846 CHECK_NUMBER (lines
, 0);
848 CHECK_WINDOW (window
, 0);
850 XSET (window
, Lisp_Window
, selected_window
);
852 pos
= *vmotion (point
, XINT (lines
), width
,
853 /* Not XFASTINT since perhaps could be negative */
854 XINT (w
->hscroll
), window
);
857 return make_number (pos
.vpos
);
862 DEFVAR_BOOL ("indent-tabs-mode", &indent_tabs_mode
,
863 "*Indentation can insert tabs if this is non-nil.\n\
864 Setting this variable automatically makes it local to the current buffer.");
865 indent_tabs_mode
= 1;
867 defsubr (&Scurrent_indentation
);
868 defsubr (&Sindent_to
);
869 defsubr (&Scurrent_column
);
870 defsubr (&Smove_to_column
);
871 defsubr (&Svertical_motion
);
872 defsubr (&Scompute_motion
);