1 /* Markers: examining, setting and killing.
2 Copyright (C) 1985, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
4 This file is part of XEmacs.
6 XEmacs is free software; you can redistribute it and/or modify it
7 under the terms of the GNU General Public License as published by the
8 Free Software Foundation; either version 2, or (at your option) any
11 XEmacs is distributed in the hope that it will be useful, but WITHOUT
12 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 You should have received a copy of the GNU General Public License
17 along with XEmacs; see the file COPYING. If not, write to
18 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
21 /* Synched up with: FSF 19.30. */
23 /* This file has been Mule-ized. */
25 /* Note that markers are currently kept in an unordered list.
26 This means that marker operations may be inefficient if
27 there are a bunch of markers in the buffer. This probably
28 won't have a significant impact on redisplay (which uses
29 markers), but if it does, it wouldn't be too hard to change
30 to an ordered gap array. (Just copy the code from extents.c.)
39 mark_marker (Lisp_Object obj)
41 Lisp_Marker *marker = XMARKER (obj);
43 /* DO NOT mark through the marker's chain.
44 The buffer's markers chain does not preserve markers from gc;
45 Instead, markers are removed from the chain when they are freed
51 XSETBUFFER (buf, marker->buffer);
56 print_marker (Lisp_Object obj, Lisp_Object printcharfun, int escapeflag)
58 Lisp_Marker *marker = XMARKER (obj);
62 error ("printing unreadable object #<marker 0x%lx>", (long) marker);
64 write_c_string (GETTEXT ("#<marker "), printcharfun);
66 write_c_string (GETTEXT ("in no buffer"), printcharfun);
69 sprintf (buf, "at %ld in ", (long) marker_position (obj));
70 write_c_string (buf, printcharfun);
71 print_internal (marker->buffer->name, printcharfun, 0);
73 sprintf (buf, " 0x%lx>", (long) marker);
74 write_c_string (buf, printcharfun);
78 marker_equal (Lisp_Object obj1, Lisp_Object obj2, int depth)
80 Lisp_Marker *marker1 = XMARKER (obj1);
81 Lisp_Marker *marker2 = XMARKER (obj2);
83 return ((marker1->buffer == marker2->buffer) &&
84 (marker1->memind == marker2->memind ||
85 /* All markers pointing nowhere are equal */
90 marker_hash (Lisp_Object obj, int depth)
92 unsigned long hash = (unsigned long) XMARKER (obj)->buffer;
94 hash = HASH2 (hash, XMARKER (obj)->memind);
98 static const struct lrecord_description marker_description[] = {
99 { XD_LISP_OBJECT, offsetof (Lisp_Marker, next) },
100 { XD_LISP_OBJECT, offsetof (Lisp_Marker, prev) },
101 { XD_LISP_OBJECT, offsetof (Lisp_Marker, buffer) },
105 DEFINE_BASIC_LRECORD_IMPLEMENTATION ("marker", marker,
106 mark_marker, print_marker, 0,
107 marker_equal, marker_hash, marker_description,
110 /* Operations on markers. */
112 DEFUN ("marker-buffer", Fmarker_buffer, 1, 1, 0, /*
113 Return the buffer that MARKER points into, or nil if none.
114 Return nil if MARKER points into a dead buffer or doesn't point anywhere.
119 CHECK_MARKER (marker);
120 /* Return marker's buffer only if it is not dead. */
121 if ((buf = XMARKER (marker)->buffer) && BUFFER_LIVE_P (buf))
124 XSETBUFFER (buffer, buf);
130 DEFUN ("marker-position", Fmarker_position, 1, 1, 0, /*
131 Return the position MARKER points at, as a character number.
132 Return `nil' if marker doesn't point anywhere.
136 CHECK_MARKER (marker);
137 return XMARKER (marker)->buffer ? make_int (marker_position (marker)) : Qnil;
140 #if 0 /* useful debugging function */
143 check_marker_circularities (struct buffer *buf)
145 Lisp_Marker *tortoise, *hare;
147 tortoise = BUF_MARKERS (buf);
155 assert (hare->buffer == buf);
159 assert (hare->buffer == buf);
163 tortoise = tortoise->next;
164 assert (tortoise != hare);
171 set_marker_internal (Lisp_Object marker, Lisp_Object pos, Lisp_Object buffer,
179 CHECK_MARKER (marker);
181 point_p = POINT_MARKER_P (marker);
183 /* If position is nil or a marker that points nowhere,
184 make this marker point nowhere. */
186 (MARKERP (pos) && !XMARKER (pos)->buffer))
189 signal_simple_error ("Can't make point-marker point nowhere",
191 if (XMARKER (marker)->buffer)
192 unchain_marker (marker);
196 CHECK_INT_COERCE_MARKER (pos);
201 CHECK_BUFFER (buffer);
202 b = XBUFFER (buffer);
203 /* If buffer is dead, set marker to point nowhere. */
204 if (!BUFFER_LIVE_P (XBUFFER (buffer)))
208 ("Can't move point-marker in a killed buffer", marker);
209 if (XMARKER (marker)->buffer)
210 unchain_marker (marker);
216 m = XMARKER (marker);
220 if (charno < BUF_BEGV (b)) charno = BUF_BEGV (b);
221 if (charno > BUF_ZV (b)) charno = BUF_ZV (b);
225 if (charno < BUF_BEG (b)) charno = BUF_BEG (b);
226 if (charno > BUF_Z (b)) charno = BUF_Z (b);
231 #ifndef moving_point_by_moving_its_marker_is_a_bug
232 BUF_SET_PT (b, charno); /* this will move the marker */
233 #else /* It's not a feature, so it must be a bug */
234 signal_simple_error ("DEBUG: attempt to move point via point-marker",
240 m->memind = bufpos_to_memind (b, charno);
246 signal_simple_error ("Can't change buffer of point-marker", marker);
248 unchain_marker (marker);
250 marker_next (m) = BUF_MARKERS (b);
253 marker_prev (BUF_MARKERS (b)) = m;
261 DEFUN ("set-marker", Fset_marker, 2, 3, 0, /*
262 Position MARKER before character number NUMBER in BUFFER.
263 BUFFER defaults to the current buffer.
264 If NUMBER is nil, makes marker point nowhere.
265 Then it no longer slows down editing in any buffer.
266 If this marker was returned by (point-marker t), then changing its position
267 moves point. You cannot change its buffer or make it point nowhere.
270 (marker, number, buffer))
272 return set_marker_internal (marker, number, buffer, 0);
276 /* This version of Fset_marker won't let the position
277 be outside the visible part. */
279 set_marker_restricted (Lisp_Object marker, Lisp_Object pos, Lisp_Object buffer)
281 return set_marker_internal (marker, pos, buffer, 1);
285 /* This is called during garbage collection,
286 so we must be careful to ignore and preserve mark bits,
287 including those in chain fields of markers. */
290 unchain_marker (Lisp_Object m)
292 Lisp_Marker *marker = XMARKER (m);
293 struct buffer *b = marker->buffer;
298 #ifdef ERROR_CHECK_GC
299 assert (BUFFER_LIVE_P (b));
302 if (marker_next (marker))
303 marker_prev (marker_next (marker)) = marker_prev (marker);
304 if (marker_prev (marker))
305 marker_next (marker_prev (marker)) = marker_next (marker);
307 BUF_MARKERS (b) = marker_next (marker);
309 #ifdef ERROR_CHECK_GC
310 assert (marker != XMARKER (b->point_marker));
317 bi_marker_position (Lisp_Object marker)
319 Lisp_Marker *m = XMARKER (marker);
320 struct buffer *buf = m->buffer;
324 error ("Marker does not point anywhere");
326 /* FSF claims that marker indices could end up denormalized, i.e.
327 in the gap. This is way bogus if it ever happens, and means
328 something fucked up elsewhere. Since I've overhauled all this
329 shit, I don't think this can happen. In any case, the following
330 macro has an assert() in it that will catch these denormalized
332 pos = memind_to_bytind (buf, m->memind);
334 #ifdef ERROR_CHECK_BUFPOS
335 if (pos < BI_BUF_BEG (buf) || pos > BI_BUF_Z (buf))
343 marker_position (Lisp_Object marker)
345 struct buffer *buf = XMARKER (marker)->buffer;
348 error ("Marker does not point anywhere");
350 return bytind_to_bufpos (buf, bi_marker_position (marker));
354 set_bi_marker_position (Lisp_Object marker, Bytind pos)
356 Lisp_Marker *m = XMARKER (marker);
357 struct buffer *buf = m->buffer;
360 error ("Marker does not point anywhere");
362 #ifdef ERROR_CHECK_BUFPOS
363 if (pos < BI_BUF_BEG (buf) || pos > BI_BUF_Z (buf))
367 m->memind = bytind_to_memind (buf, pos);
371 set_marker_position (Lisp_Object marker, Bufpos pos)
373 struct buffer *buf = XMARKER (marker)->buffer;
376 error ("Marker does not point anywhere");
378 set_bi_marker_position (marker, bufpos_to_bytind (buf, pos));
382 copy_marker_1 (Lisp_Object marker, Lisp_Object type, int noseeum)
384 REGISTER Lisp_Object new;
388 if (INTP (marker) || MARKERP (marker))
391 new = noseeum_make_marker ();
393 new = Fmake_marker ();
394 Fset_marker (new, marker,
395 (MARKERP (marker) ? Fmarker_buffer (marker) : Qnil));
396 XMARKER (new)->insertion_type = !NILP (type);
400 marker = wrong_type_argument (Qinteger_or_marker_p, marker);
403 RETURN_NOT_REACHED (Qnil) /* not reached */
406 DEFUN ("copy-marker", Fcopy_marker, 1, 2, 0, /*
407 Return a new marker pointing at the same place as MARKER.
408 If argument is a number, makes a new marker pointing
409 at that position in the current buffer.
410 The optional argument TYPE specifies the insertion type of the new marker;
411 see `marker-insertion-type'.
415 return copy_marker_1 (marker, type, 0);
419 noseeum_copy_marker (Lisp_Object marker, Lisp_Object type)
421 return copy_marker_1 (marker, type, 1);
424 DEFUN ("marker-insertion-type", Fmarker_insertion_type, 1, 1, 0, /*
425 Return insertion type of MARKER: t if it stays after inserted text.
426 nil means the marker stays before text inserted there.
430 CHECK_MARKER (marker);
431 return XMARKER (marker)->insertion_type ? Qt : Qnil;
434 DEFUN ("set-marker-insertion-type", Fset_marker_insertion_type, 2, 2, 0, /*
435 Set the insertion-type of MARKER to TYPE.
436 If TYPE is t, it means the marker advances when you insert text at it.
437 If TYPE is nil, it means the marker stays behind when you insert text at it.
441 CHECK_MARKER (marker);
443 XMARKER (marker)->insertion_type = ! NILP (type);
447 /* #### What is the possible use of this? It looks quite useless to
448 me, because there is no way to find *which* markers are positioned
449 at POSITION. Additional bogosity bonus: (buffer-has-markers-at
450 (point)) will always return t because of the `point-marker'. The
451 same goes for the position of mark. Bletch!
453 Someone should discuss this with Stallman, but I don't have the
454 stomach. In fact, this function sucks so badly that I'm disabling
455 it by default (although I've debugged it). If you want to use it,
456 use extents instead. --hniksic */
458 xxDEFUN ("buffer-has-markers-at", Fbuffer_has_markers_at, 1, 1, 0, /*
459 Return t if there are markers pointing at POSITION in the current buffer.
466 /* A small optimization trick: convert POS to memind now, rather
467 than converting every marker's memory index to bufpos. */
468 pos = bytind_to_memind (current_buffer,
469 get_buffer_pos_byte (current_buffer, position,
472 for (marker = BUF_MARKERS (current_buffer);
474 marker = marker_next (marker))
476 /* We use marker->memind, so we don't have to go through the
477 unwieldy operation of creating a Lisp_Object for
478 marker_position() every time around. */
479 if (marker->memind == pos)
487 #ifdef MEMORY_USAGE_STATS
490 compute_buffer_marker_usage (struct buffer *b, struct overhead_stats *ovstats)
496 for (m = BUF_MARKERS (b); m; m = m->next)
497 total += sizeof (Lisp_Marker);
498 ovstats->was_requested += total;
499 overhead = fixed_type_block_overhead (total);
500 /* #### claiming this is all malloc overhead is not really right,
501 but it has to go somewhere. */
502 ovstats->malloc_overhead += overhead;
503 return total + overhead;
506 #endif /* MEMORY_USAGE_STATS */
510 syms_of_marker (void)
512 INIT_LRECORD_IMPLEMENTATION (marker);
514 DEFSUBR (Fmarker_position);
515 DEFSUBR (Fmarker_buffer);
516 DEFSUBR (Fset_marker);
517 DEFSUBR (Fcopy_marker);
518 DEFSUBR (Fmarker_insertion_type);
519 DEFSUBR (Fset_marker_insertion_type);
520 #if 0 /* FSFmacs crock */
521 DEFSUBR (Fbuffer_has_markers_at);
526 init_buffer_markers (struct buffer *b)
531 b->mark = Fmake_marker ();
533 b->point_marker = Fmake_marker ();
534 Fset_marker (b->point_marker,
535 /* For indirect buffers, point is already set. */
536 b->base_buffer ? make_int (BUF_PT (b)) : make_int (1),
541 uninit_buffer_markers (struct buffer *b)
543 /* Unchain all markers of this buffer
544 and leave them pointing nowhere. */
545 REGISTER Lisp_Marker *m, *next;
546 for (m = BUF_MARKERS (b); m; m = next)
549 next = marker_next (m);