editfns.c 124 KB
Newer Older
Jim Blandy's avatar
Jim Blandy committed
1
/* Lisp functions pertaining to editing.
2
   Copyright (C) 1985,86,87,89,93,94,95,96,97,98, 1999, 2000, 2001
3
	Free Software Foundation, Inc.
Jim Blandy's avatar
Jim Blandy committed
4 5 6 7 8

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
Karl Heuer's avatar
Karl Heuer committed
9
the Free Software Foundation; either version 2, or (at your option)
Jim Blandy's avatar
Jim Blandy committed
10 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
along with GNU Emacs; see the file COPYING.  If not, write to
Richard M. Stallman's avatar
Richard M. Stallman committed
19 20
the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */
Jim Blandy's avatar
Jim Blandy committed
21 22


23
#include <config.h>
Pavel Janík's avatar
Pavel Janík committed
24
#include <ctype.h>
25
#include <sys/types.h>
Jim Blandy's avatar
Jim Blandy committed
26 27

#ifdef VMS
Jim Blandy's avatar
Jim Blandy committed
28
#include "vms-pwd.h"
Jim Blandy's avatar
Jim Blandy committed
29
#else
Jim Blandy's avatar
Jim Blandy committed
30
#include <pwd.h>
Jim Blandy's avatar
Jim Blandy committed
31 32
#endif

Andreas Schwab's avatar
Andreas Schwab committed
33 34 35 36
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

Jim Blandy's avatar
Jim Blandy committed
37
#include "lisp.h"
38
#include "intervals.h"
Jim Blandy's avatar
Jim Blandy committed
39
#include "buffer.h"
Karl Heuer's avatar
Karl Heuer committed
40
#include "charset.h"
41
#include "coding.h"
42
#include "frame.h"
Jim Blandy's avatar
Jim Blandy committed
43 44
#include "window.h"

Jim Blandy's avatar
Jim Blandy committed
45
#include "systime.h"
Jim Blandy's avatar
Jim Blandy committed
46

47 48 49 50 51 52 53
#ifdef STDC_HEADERS
#include <float.h>
#define MAX_10_EXP	DBL_MAX_10_EXP
#else
#define MAX_10_EXP	310
#endif

54 55 56 57
#ifndef NULL
#define NULL 0
#endif

58
#ifndef USE_CRT_DLL
59
extern char **environ;
60 61
#endif

62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78
extern Lisp_Object make_time P_ ((time_t));
extern size_t emacs_strftimeu P_ ((char *, size_t, const char *,
				   const struct tm *, int));
static int tm_diff P_ ((struct tm *, struct tm *));
static void find_field P_ ((Lisp_Object, Lisp_Object, int *, int *));
static void update_buffer_properties P_ ((int, int));
static Lisp_Object region_limit P_ ((int));
static int lisp_time_argument P_ ((Lisp_Object, time_t *, int *));
static size_t emacs_memftimeu P_ ((char *, size_t, const char *,
				   size_t, const struct tm *, int));
static void general_insert_function P_ ((void (*) (unsigned char *, int),
					 void (*) (Lisp_Object, int, int, int,
						   int, int),
					 int, int, Lisp_Object *));
static Lisp_Object subst_char_in_region_unwind P_ ((Lisp_Object));
static Lisp_Object subst_char_in_region_unwind_1 P_ ((Lisp_Object));
static void transpose_markers P_ ((int, int, int, int, int, int, int, int));
79

Gerd Moellmann's avatar
Gerd Moellmann committed
80 81 82 83
#ifdef HAVE_INDEX
extern char *index P_ ((const char *, int));
#endif

84 85 86
Lisp_Object Vbuffer_access_fontify_functions;
Lisp_Object Qbuffer_access_fontify_functions;
Lisp_Object Vbuffer_access_fontified_property;
87

88
Lisp_Object Fuser_full_name P_ ((Lisp_Object));
89

90 91 92 93
/* Non-nil means don't stop at field boundary in text motion commands.  */

Lisp_Object Vinhibit_field_text_motion;

Jim Blandy's avatar
Jim Blandy committed
94 95 96
/* Some static data, and a function to initialize it for each run */

Lisp_Object Vsystem_name;
97 98 99
Lisp_Object Vuser_real_login_name;	/* login name of current user ID */
Lisp_Object Vuser_full_name;		/* full name of current user */
Lisp_Object Vuser_login_name;		/* user name from LOGNAME or USER */
Jim Blandy's avatar
Jim Blandy committed
100

101 102 103 104 105 106 107 108 109
/* Symbol for the text property used to mark fields.  */

Lisp_Object Qfield;

/* A special value for Qfield properties.  */

Lisp_Object Qboundary;


Jim Blandy's avatar
Jim Blandy committed
110 111 112
void
init_editfns ()
{
Jim Blandy's avatar
Jim Blandy committed
113
  char *user_name;
114
  register unsigned char *p;
Jim Blandy's avatar
Jim Blandy committed
115 116 117 118
  struct passwd *pw;	/* password entry for the current user */
  Lisp_Object tem;

  /* Set up system_name even when dumping.  */
119
  init_system_name ();
Jim Blandy's avatar
Jim Blandy committed
120 121 122 123 124 125 126 127

#ifndef CANNOT_DUMP
  /* Don't bother with this on initial start when just dumping out */
  if (!initialized)
    return;
#endif /* not CANNOT_DUMP */

  pw = (struct passwd *) getpwuid (getuid ());
Morten Welinder's avatar
Morten Welinder committed
128 129 130 131
#ifdef MSDOS
  /* We let the real user name default to "root" because that's quite
     accurate on MSDOG and because it lets Emacs find the init file.
     (The DVX libraries override the Djgpp libraries here.)  */
132
  Vuser_real_login_name = build_string (pw ? pw->pw_name : "root");
Morten Welinder's avatar
Morten Welinder committed
133
#else
134
  Vuser_real_login_name = build_string (pw ? pw->pw_name : "unknown");
Morten Welinder's avatar
Morten Welinder committed
135
#endif
Jim Blandy's avatar
Jim Blandy committed
136

Jim Blandy's avatar
Jim Blandy committed
137 138
  /* Get the effective user name, by consulting environment variables,
     or the effective uid if those are unset.  */
139
  user_name = (char *) getenv ("LOGNAME");
Jim Blandy's avatar
Jim Blandy committed
140
  if (!user_name)
141 142 143
#ifdef WINDOWSNT
    user_name = (char *) getenv ("USERNAME");	/* it's USERNAME on NT */
#else  /* WINDOWSNT */
144
    user_name = (char *) getenv ("USER");
145
#endif /* WINDOWSNT */
Jim Blandy's avatar
Jim Blandy committed
146 147 148 149 150
  if (!user_name)
    {
      pw = (struct passwd *) getpwuid (geteuid ());
      user_name = (char *) (pw ? pw->pw_name : "unknown");
    }
151
  Vuser_login_name = build_string (user_name);
Jim Blandy's avatar
Jim Blandy committed
152

Jim Blandy's avatar
Jim Blandy committed
153 154
  /* If the user name claimed in the environment vars differs from
     the real uid, use the claimed name to find the full name.  */
155
  tem = Fstring_equal (Vuser_login_name, Vuser_real_login_name);
156 157
  Vuser_full_name = Fuser_full_name (NILP (tem)? make_number (geteuid())
				     : Vuser_login_name);
Sam Steingold's avatar
Sam Steingold committed
158

159
  p = (unsigned char *) getenv ("NAME");
160 161
  if (p)
    Vuser_full_name = build_string (p);
162 163
  else if (NILP (Vuser_full_name))
    Vuser_full_name = build_string ("unknown");
Jim Blandy's avatar
Jim Blandy committed
164 165 166
}

DEFUN ("char-to-string", Fchar_to_string, Schar_to_string, 1, 1, 0,
167 168
       doc: /* Convert arg CHARACTER to a string containing that character.  */)
     (character)
169
     Lisp_Object character;
Jim Blandy's avatar
Jim Blandy committed
170
{
Karl Heuer's avatar
Karl Heuer committed
171
  int len;
172
  unsigned char str[MAX_MULTIBYTE_LENGTH];
Karl Heuer's avatar
Karl Heuer committed
173

174
  CHECK_NUMBER (character, 0);
Jim Blandy's avatar
Jim Blandy committed
175

176 177 178
  len = (SINGLE_BYTE_CHAR_P (XFASTINT (character))
	 ? (*str = (unsigned char)(XFASTINT (character)), 1)
	 : char_to_string (XFASTINT (character), str));
179
  return make_string_from_bytes (str, 1, len);
Jim Blandy's avatar
Jim Blandy committed
180 181 182
}

DEFUN ("string-to-char", Fstring_to_char, Sstring_to_char, 1, 1, 0,
183 184 185
       doc: /* Convert arg STRING to a character, the first character of that string.
A multibyte character is handled correctly.  */)
     (string)
186
     register Lisp_Object string;
Jim Blandy's avatar
Jim Blandy committed
187 188 189
{
  register Lisp_Object val;
  register struct Lisp_String *p;
190 191
  CHECK_STRING (string, 0);
  p = XSTRING (string);
Jim Blandy's avatar
Jim Blandy committed
192
  if (p->size)
193 194 195 196 197 198
    {
      if (STRING_MULTIBYTE (string))
	XSETFASTINT (val, STRING_CHAR (p->data, STRING_BYTES (p)));
      else
	XSETFASTINT (val, p->data[0]);
    }
Jim Blandy's avatar
Jim Blandy committed
199
  else
200
    XSETFASTINT (val, 0);
Jim Blandy's avatar
Jim Blandy committed
201 202 203 204
  return val;
}

static Lisp_Object
205 206
buildmark (charpos, bytepos)
     int charpos, bytepos;
Jim Blandy's avatar
Jim Blandy committed
207 208 209
{
  register Lisp_Object mark;
  mark = Fmake_marker ();
210
  set_marker_both (mark, Qnil, charpos, bytepos);
Jim Blandy's avatar
Jim Blandy committed
211 212 213 214
  return mark;
}

DEFUN ("point", Fpoint, Spoint, 0, 0, 0,
215 216 217
       doc: /* Return value of point, as an integer.
Beginning of buffer is position (point-min).  */)
     ()
Jim Blandy's avatar
Jim Blandy committed
218 219
{
  Lisp_Object temp;
220
  XSETFASTINT (temp, PT);
Jim Blandy's avatar
Jim Blandy committed
221 222 223 224
  return temp;
}

DEFUN ("point-marker", Fpoint_marker, Spoint_marker, 0, 0, 0,
225 226
       doc: /* Return value of point, as a marker object.  */)
     ()
Jim Blandy's avatar
Jim Blandy committed
227
{
228
  return buildmark (PT, PT_BYTE);
Jim Blandy's avatar
Jim Blandy committed
229 230 231 232 233 234 235 236 237 238 239 240 241 242 243
}

int
clip_to_bounds (lower, num, upper)
     int lower, num, upper;
{
  if (num < lower)
    return lower;
  else if (num > upper)
    return upper;
  else
    return num;
}

DEFUN ("goto-char", Fgoto_char, Sgoto_char, 1, 1, "NGoto char: ",
244
       doc: /* Set point to POSITION, a number or marker.
Pavel Janík's avatar
Pavel Janík committed
245 246 247
Beginning of buffer is position (point-min), end is (point-max).
If the position is in the middle of a multibyte form,
the actual point is set at the head of the multibyte form
248 249
except in the case that `enable-multibyte-characters' is nil.  */)
     (position)
250
     register Lisp_Object position;
Jim Blandy's avatar
Jim Blandy committed
251
{
Karl Heuer's avatar
Karl Heuer committed
252 253
  int pos;

254 255
  if (MARKERP (position)
      && current_buffer == XMARKER (position)->buffer)
256 257 258 259 260 261 262 263 264 265 266 267
    {
      pos = marker_position (position);
      if (pos < BEGV)
	SET_PT_BOTH (BEGV, BEGV_BYTE);
      else if (pos > ZV)
	SET_PT_BOTH (ZV, ZV_BYTE);
      else
	SET_PT_BOTH (pos, marker_byte_position (position));

      return position;
    }

268
  CHECK_NUMBER_COERCE_MARKER (position, 0);
Jim Blandy's avatar
Jim Blandy committed
269

Karl Heuer's avatar
Karl Heuer committed
270 271
  pos = clip_to_bounds (BEGV, XINT (position), ZV);
  SET_PT (pos);
272
  return position;
Jim Blandy's avatar
Jim Blandy committed
273 274
}

275 276 277 278 279

/* Return the start or end position of the region.
   BEGINNINGP non-zero means return the start.
   If there is no region active, signal an error. */

Jim Blandy's avatar
Jim Blandy committed
280 281 282 283
static Lisp_Object
region_limit (beginningp)
     int beginningp;
{
284
  extern Lisp_Object Vmark_even_if_inactive; /* Defined in callint.c. */
285 286 287 288
  Lisp_Object m;
  
  if (!NILP (Vtransient_mark_mode)
      && NILP (Vmark_even_if_inactive)
289 290
      && NILP (current_buffer->mark_active))
    Fsignal (Qmark_inactive, Qnil);
291
  
Jim Blandy's avatar
Jim Blandy committed
292
  m = Fmarker_position (current_buffer->mark);
293 294 295
  if (NILP (m))
    error ("There is no region now");
  
296
  if ((PT < XFASTINT (m)) == beginningp)
297 298
    m = make_number (PT);
  return m;
Jim Blandy's avatar
Jim Blandy committed
299 300 301
}

DEFUN ("region-beginning", Fregion_beginning, Sregion_beginning, 0, 0, 0,
302 303
       doc: /* Return position of beginning of region, as an integer.  */)
     ()
Jim Blandy's avatar
Jim Blandy committed
304
{
305
  return region_limit (1);
Jim Blandy's avatar
Jim Blandy committed
306 307 308
}

DEFUN ("region-end", Fregion_end, Sregion_end, 0, 0, 0,
309 310
       doc: /* Return position of end of region, as an integer.  */)
     ()
Jim Blandy's avatar
Jim Blandy committed
311
{
312
  return region_limit (0);
Jim Blandy's avatar
Jim Blandy committed
313 314 315
}

DEFUN ("mark-marker", Fmark_marker, Smark_marker, 0, 0, 0,
316
       doc: /* Return this buffer's mark, as a marker object.
Pavel Janík's avatar
Pavel Janík committed
317
Watch out!  Moving this marker changes the mark position.
318 319
If you set the marker not to point anywhere, the buffer will have no mark.  */)
     ()
Jim Blandy's avatar
Jim Blandy committed
320 321 322
{
  return current_buffer->mark;
}
323

324

325 326
#if 0 /* Not used.  */

327 328
/* Return nonzero if POS1 and POS2 have the same value
   for the text property PROP.  */
329 330

static int
331
char_property_eq (prop, pos1, pos2)
332 333 334 335 336
     Lisp_Object prop;
     Lisp_Object pos1, pos2;
{
  Lisp_Object pval1, pval2;

337 338
  pval1 = Fget_char_property (pos1, prop, Qnil);
  pval2 = Fget_char_property (pos2, prop, Qnil);
339 340 341 342

  return EQ (pval1, pval2);
}

343 344
#endif /* 0 */

Miles Bader's avatar
Miles Bader committed
345
/* Return the direction from which the text-property PROP would be
346 347 348 349
   inherited by any new text inserted at POS: 1 if it would be
   inherited from the char after POS, -1 if it would be inherited from
   the char before POS, and 0 if from neither.  */

350
static int
Miles Bader's avatar
Miles Bader committed
351
text_property_stickiness (prop, pos)
352 353 354
     Lisp_Object prop;
     Lisp_Object pos;
{
355 356
  Lisp_Object prev_pos, front_sticky;
  int is_rear_sticky = 1, is_front_sticky = 0; /* defaults */
357

358 359
  if (XINT (pos) > BEGV)
    /* Consider previous character.  */
360
    {
361 362 363 364 365 366 367 368 369 370
      Lisp_Object rear_non_sticky;

      prev_pos = make_number (XINT (pos) - 1);
      rear_non_sticky = Fget_text_property (prev_pos, Qrear_nonsticky, Qnil);

      if (CONSP (rear_non_sticky)
	  ? Fmemq (prop, rear_non_sticky)
	  : !NILP (rear_non_sticky))
	/* PROP is rear-non-sticky.  */
	is_rear_sticky = 0;
371 372
    }

373
  /* Consider following character.  */
Miles Bader's avatar
Miles Bader committed
374
  front_sticky = Fget_text_property (pos, Qfront_sticky, Qnil);
375 376 377

  if (EQ (front_sticky, Qt)
      || (CONSP (front_sticky)
378
	  && !NILP (Fmemq (prop, front_sticky))))
379
    /* PROP is inherited from after.  */
380
    is_front_sticky = 1;
381

382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397
  /* Simple cases, where the properties are consistent.  */
  if (is_rear_sticky && !is_front_sticky)
    return -1;
  else if (!is_rear_sticky && is_front_sticky)
    return 1;
  else if (!is_rear_sticky && !is_front_sticky)
    return 0;

  /* The stickiness properties are inconsistent, so we have to
     disambiguate.  Basically, rear-sticky wins, _except_ if the
     property that would be inherited has a value of nil, in which case
     front-sticky wins.  */
  if (XINT (pos) == BEGV || NILP (Fget_text_property (prev_pos, prop, Qnil)))
    return 1;
  else
    return -1;
398
}
399

400

401
/* Find the field surrounding POS in *BEG and *END.  If POS is nil,
402 403
   the value of point is used instead.  If BEG or END null,
   means don't store the beginning or end of the field.
404 405

   If MERGE_AT_BOUNDARY is nonzero, then if POS is at the very first
406 407 408 409 410 411 412 413
   position of a field, then the beginning of the previous field is
   returned instead of the beginning of POS's field (since the end of a
   field is actually also the beginning of the next input field, this
   behavior is sometimes useful).  Additionally in the MERGE_AT_BOUNDARY
   true case, if two fields are separated by a field with the special
   value `boundary', and POS lies within it, then the two separated
   fields are considered to be adjacent, and POS between them, when
   finding the beginning and ending of the "merged" field.
414 415 416 417

   Either BEG or END may be 0, in which case the corresponding value
   is not stored.  */

418
static void
419 420 421 422 423
find_field (pos, merge_at_boundary, beg, end)
     Lisp_Object pos;
     Lisp_Object merge_at_boundary;
     int *beg, *end;
{
424 425
  /* Fields right before and after the point.  */
  Lisp_Object before_field, after_field;
Miles Bader's avatar
Miles Bader committed
426 427 428
  /* If the fields came from overlays, the associated overlays.
     Qnil means they came from text-properties.  */
  Lisp_Object before_overlay = Qnil, after_overlay = Qnil;
429 430 431 432
  /* 1 if POS counts as the start of a field.  */
  int at_field_start = 0;
  /* 1 if POS counts as the end of a field.  */
  int at_field_end = 0;
433

434 435 436 437 438
  if (NILP (pos))
    XSETFASTINT (pos, PT);
  else
    CHECK_NUMBER_COERCE_MARKER (pos, 0);

439
  after_field
Miles Bader's avatar
Miles Bader committed
440
    = get_char_property_and_overlay (pos, Qfield, Qnil, &after_overlay);
441 442
  before_field
    = (XFASTINT (pos) > BEGV
Miles Bader's avatar
Miles Bader committed
443 444 445
       ? get_char_property_and_overlay (make_number (XINT (pos) - 1),
					Qfield, Qnil,
					&before_overlay)
446
       : Qnil);
447 448 449 450 451 452 453 454 455 456 457

  /* See if we need to handle the case where MERGE_AT_BOUNDARY is nil
     and POS is at beginning of a field, which can also be interpreted
     as the end of the previous field.  Note that the case where if
     MERGE_AT_BOUNDARY is non-nil (see function comment) is actually the
     more natural one; then we avoid treating the beginning of a field
     specially.  */
  if (NILP (merge_at_boundary) && !EQ (after_field, before_field))
    /* We are at a boundary, see which direction is inclusive.  We
       decide by seeing which field the `field' property sticks to.  */
    {
Miles Bader's avatar
Miles Bader committed
458 459 460 461 462 463 464 465 466 467 468 469 470
      /* -1 means insertions go into before_field, 1 means they go
	 into after_field, 0 means neither.  */
      int stickiness;
      /* Whether the before/after_field come from overlays.  */
      int bop = !NILP (before_overlay);
      int aop = !NILP (after_overlay);

      if (bop && XMARKER (OVERLAY_END (before_overlay))->insertion_type == 1)
	/* before_field is from an overlay, which expands upon
	   end-insertions.  Note that it's possible for after_overlay to
	   also eat insertions here, but then they will overlap, and
	   there's not much we can do.  */
	stickiness = -1;
Miles Bader's avatar
Miles Bader committed
471 472
      else if (aop
	       && XMARKER (OVERLAY_START (after_overlay))->insertion_type == 0)
Miles Bader's avatar
Miles Bader committed
473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493
	/* after_field is from an overlay, which expand to contain
	   start-insertions.  */
	stickiness = 1;
      else if (bop && aop)
	/* Both fields come from overlays, but neither will contain any
	   insertion here.  */
	stickiness = 0;
      else if (bop)
	/* before_field is an overlay that won't eat any insertion, but
	   after_field is from a text-property.  Assume that the
	   text-property continues underneath the overlay, and so will
	   be inherited by any insertion, regardless of any stickiness
	   settings.  */
	stickiness = 1;
      else if (aop)
	/* Similarly, when after_field is the overlay.  */
	stickiness = -1;
      else
	/* Both fields come from text-properties.  Look for explicit
	   stickiness properties.  */
	stickiness = text_property_stickiness (Qfield, pos);
494 495 496 497 498 499 500 501 502 503

      if (stickiness > 0)
	at_field_start = 1;
      else if (stickiness < 0)
	at_field_end = 1;
      else
	/* STICKINESS == 0 means that any inserted text will get a
	   `field' char-property of nil, so check to see if that
	   matches either of the adjacent characters (this being a
	   kind of "stickiness by default").  */
504
	{
505 506 507 508
	  if (NILP (before_field))
	    at_field_end = 1; /* Sticks to the left.  */
	  else if (NILP (after_field))
	    at_field_start = 1; /* Sticks to the right.  */
509 510 511
	}
    }

512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533
  /* Note about special `boundary' fields:

     Consider the case where the point (`.') is between the fields `x' and `y':

	xxxx.yyyy

     In this situation, if merge_at_boundary is true, we consider the
     `x' and `y' fields as forming one big merged field, and so the end
     of the field is the end of `y'.

     However, if `x' and `y' are separated by a special `boundary' field
     (a field with a `field' char-property of 'boundary), then we ignore
     this special field when merging adjacent fields.  Here's the same
     situation, but with a `boundary' field between the `x' and `y' fields:

	xxx.BBBByyyy

     Here, if point is at the end of `x', the beginning of `y', or
     anywhere in-between (within the `boundary' field), we merge all
     three fields and consider the beginning as being the beginning of
     the `x' field, and the end as being the end of the `y' field.  */

534
  if (beg)
535 536 537 538 539 540 541 542 543 544 545
    {
      if (at_field_start)
	/* POS is at the edge of a field, and we should consider it as
	   the beginning of the following field.  */
	*beg = XFASTINT (pos);
      else
	/* Find the previous field boundary.  */
	{
	  if (!NILP (merge_at_boundary) && EQ (before_field, Qboundary))
	    /* Skip a `boundary' field.  */
	    pos = Fprevious_single_char_property_change (pos, Qfield, Qnil,Qnil);
546

547 548 549 550
	  pos = Fprevious_single_char_property_change (pos, Qfield, Qnil, Qnil);
	  *beg = NILP (pos) ? BEGV : XFASTINT (pos);
	}
    }
551 552

  if (end)
553 554 555 556 557 558 559 560 561 562 563
    {
      if (at_field_end)
	/* POS is at the edge of a field, and we should consider it as
	   the end of the previous field.  */
	*end = XFASTINT (pos);
      else
	/* Find the next field boundary.  */
	{
	  if (!NILP (merge_at_boundary) && EQ (after_field, Qboundary))
	    /* Skip a `boundary' field.  */
	    pos = Fnext_single_char_property_change (pos, Qfield, Qnil, Qnil);
564

565 566 567 568
	  pos = Fnext_single_char_property_change (pos, Qfield, Qnil, Qnil);
	  *end = NILP (pos) ? ZV : XFASTINT (pos);
	}
    }
569
}
570

571

572
DEFUN ("delete-field", Fdelete_field, Sdelete_field, 0, 1, 0,
573
       doc: /* Delete the field surrounding POS.
Pavel Janík's avatar
Pavel Janík committed
574
A field is a region of text with the same `field' property.
575 576
If POS is nil, the value of point is used for POS.  */)
     (pos)
577 578 579 580 581 582
     Lisp_Object pos;
{
  int beg, end;
  find_field (pos, Qnil, &beg, &end);
  if (beg != end)
    del_range (beg, end);
583
  return Qnil;
584 585 586
}

DEFUN ("field-string", Ffield_string, Sfield_string, 0, 1, 0,
587
       doc: /* Return the contents of the field surrounding POS as a string.
Pavel Janík's avatar
Pavel Janík committed
588
A field is a region of text with the same `field' property.
589 590
If POS is nil, the value of point is used for POS.  */)
     (pos)
591 592 593 594 595 596 597 598
     Lisp_Object pos;
{
  int beg, end;
  find_field (pos, Qnil, &beg, &end);
  return make_buffer_string (beg, end, 1);
}

DEFUN ("field-string-no-properties", Ffield_string_no_properties, Sfield_string_no_properties, 0, 1, 0,
599
       doc: /* Return the contents of the field around POS, without text-properties.
Pavel Janík's avatar
Pavel Janík committed
600
A field is a region of text with the same `field' property.
601 602
If POS is nil, the value of point is used for POS.  */)
     (pos)
603 604 605 606 607 608 609 610
     Lisp_Object pos;
{
  int beg, end;
  find_field (pos, Qnil, &beg, &end);
  return make_buffer_string (beg, end, 0);
}

DEFUN ("field-beginning", Ffield_beginning, Sfield_beginning, 0, 2, 0,
611
       doc: /* Return the beginning of the field surrounding POS.
Pavel Janík's avatar
Pavel Janík committed
612 613 614
A field is a region of text with the same `field' property.
If POS is nil, the value of point is used for POS.
If ESCAPE-FROM-EDGE is non-nil and POS is at the beginning of its
615 616
field, then the beginning of the *previous* field is returned.  */)
     (pos, escape_from_edge)
617 618 619 620 621 622 623 624
     Lisp_Object pos, escape_from_edge;
{
  int beg;
  find_field (pos, escape_from_edge, &beg, 0);
  return make_number (beg);
}

DEFUN ("field-end", Ffield_end, Sfield_end, 0, 2, 0,
625
       doc: /* Return the end of the field surrounding POS.
Pavel Janík's avatar
Pavel Janík committed
626 627 628
A field is a region of text with the same `field' property.
If POS is nil, the value of point is used for POS.
If ESCAPE-FROM-EDGE is non-nil and POS is at the end of its field,
629 630
then the end of the *following* field is returned.  */)
     (pos, escape_from_edge)
631 632 633 634 635 636 637
     Lisp_Object pos, escape_from_edge;
{
  int end;
  find_field (pos, escape_from_edge, 0, &end);
  return make_number (end);
}

638
DEFUN ("constrain-to-field", Fconstrain_to_field, Sconstrain_to_field, 2, 5, 0,
639
       doc: /* Return the position closest to NEW-POS that is in the same field as OLD-POS.
Pavel Janík's avatar
Pavel Janík committed
640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663

A field is a region of text with the same `field' property.
If NEW-POS is nil, then the current point is used instead, and set to the
constrained position if that is different.

If OLD-POS is at the boundary of two fields, then the allowable
positions for NEW-POS depends on the value of the optional argument
ESCAPE-FROM-EDGE: If ESCAPE-FROM-EDGE is nil, then NEW-POS is
constrained to the field that has the same `field' char-property
as any new characters inserted at OLD-POS, whereas if ESCAPE-FROM-EDGE
is non-nil, NEW-POS is constrained to the union of the two adjacent
fields.  Additionally, if two fields are separated by another field with
the special value `boundary', then any point within this special field is
also considered to be `on the boundary'.

If the optional argument ONLY-IN-LINE is non-nil and constraining
NEW-POS would move it to a different line, NEW-POS is returned
unconstrained.  This useful for commands that move by line, like
\\[next-line] or \\[beginning-of-line], which should generally respect field boundaries
only in the case where they can still move to the right line.

If the optional argument INHIBIT-CAPTURE-PROPERTY is non-nil, and OLD-POS has
a non-nil property of that name, then any field boundaries are ignored.

664 665
Field boundaries are not noticed if `inhibit-field-text-motion' is non-nil.  */)
     (new_pos, old_pos, escape_from_edge, only_in_line, inhibit_capture_property)
666 667
     Lisp_Object new_pos, old_pos;
     Lisp_Object escape_from_edge, only_in_line, inhibit_capture_property;
668 669 670 671 672 673 674 675 676 677 678
{
  /* If non-zero, then the original point, before re-positioning.  */
  int orig_point = 0;

  if (NILP (new_pos))
    /* Use the current point, and afterwards, set it.  */
    {
      orig_point = PT;
      XSETFASTINT (new_pos, PT);
    }

679 680
  if (NILP (Vinhibit_field_text_motion)
      && !EQ (new_pos, old_pos)
681 682
      && (!NILP (Fget_char_property (new_pos, Qfield, Qnil))
	  || !NILP (Fget_char_property (old_pos, Qfield, Qnil)))
683 684
      && (NILP (inhibit_capture_property)
	  || NILP (Fget_char_property(old_pos, inhibit_capture_property, Qnil))))
685 686 687
    /* NEW_POS is not within the same field as OLD_POS; try to
       move NEW_POS so that it is.  */
    {
688
      int fwd, shortage;
689 690 691 692 693 694 695 696 697 698 699 700
      Lisp_Object field_bound;

      CHECK_NUMBER_COERCE_MARKER (new_pos, 0);
      CHECK_NUMBER_COERCE_MARKER (old_pos, 0);

      fwd = (XFASTINT (new_pos) > XFASTINT (old_pos));

      if (fwd)
	field_bound = Ffield_end (old_pos, escape_from_edge);
      else
	field_bound = Ffield_beginning (old_pos, escape_from_edge);

701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717
      if (/* See if ESCAPE_FROM_EDGE caused FIELD_BOUND to jump to the
             other side of NEW_POS, which would mean that NEW_POS is
             already acceptable, and it's not necessary to constrain it
             to FIELD_BOUND.  */
	  ((XFASTINT (field_bound) < XFASTINT (new_pos)) ? fwd : !fwd)
	  /* NEW_POS should be constrained, but only if either
	     ONLY_IN_LINE is nil (in which case any constraint is OK),
	     or NEW_POS and FIELD_BOUND are on the same line (in which
	     case the constraint is OK even if ONLY_IN_LINE is non-nil). */
	  && (NILP (only_in_line)
	      /* This is the ONLY_IN_LINE case, check that NEW_POS and
		 FIELD_BOUND are on the same line by seeing whether
		 there's an intervening newline or not.  */
	      || (scan_buffer ('\n',
			       XFASTINT (new_pos), XFASTINT (field_bound),
			       fwd ? -1 : 1, &shortage, 1),
		  shortage != 0)))
718 719 720 721 722 723 724 725 726 727
	/* Constrain NEW_POS to FIELD_BOUND.  */
	new_pos = field_bound;

      if (orig_point && XFASTINT (new_pos) != orig_point)
	/* The NEW_POS argument was originally nil, so automatically set PT. */
	SET_PT (XFASTINT (new_pos));
    }

  return new_pos;
}
728

729

730 731
DEFUN ("line-beginning-position",
       Fline_beginning_position, Sline_beginning_position, 0, 1, 0,
732
       doc: /* Return the character position of the first character on the current line.
Pavel Janík's avatar
Pavel Janík committed
733 734
With argument N not nil or 1, move forward N - 1 lines first.
If scan reaches end of buffer, return that position.
735 736 737 738 739

The scan does not cross a field boundary unless doing so would move
beyond there to a different line; if N is nil or 1, and scan starts at a
field boundary, the scan stops as soon as it starts.  To ignore field
boundaries bind `inhibit-field-text-motion' to t.
Pavel Janík's avatar
Pavel Janík committed
740

741 742
This function does not move point.  */)
     (n)
743 744
     Lisp_Object n;
{
745
  int orig, orig_byte, end;
746 747 748 749 750 751 752

  if (NILP (n))
    XSETFASTINT (n, 1);
  else
    CHECK_NUMBER (n, 0);

  orig = PT;
753
  orig_byte = PT_BYTE;
754 755
  Fforward_line (make_number (XINT (n) - 1));
  end = PT;
756

757
  SET_PT_BOTH (orig, orig_byte);
Jim Blandy's avatar
Jim Blandy committed
758

759
  /* Return END constrained to the current input field.  */
760 761
  return Fconstrain_to_field (make_number (end), make_number (orig),
			      XINT (n) != 1 ? Qt : Qnil,
762
			      Qt, Qnil);
763 764
}

765
DEFUN ("line-end-position", Fline_end_position, Sline_end_position, 0, 1, 0,
766
       doc: /* Return the character position of the last character on the current line.
Pavel Janík's avatar
Pavel Janík committed
767 768
With argument N not nil or 1, move forward N - 1 lines first.
If scan reaches end of buffer, return that position.
769 770 771 772 773 774

The scan does not cross a field boundary unless doing so would move
beyond there to a different line; if N is nil or 1, and scan starts at a
field boundary, the scan stops as soon as it starts.  To ignore field
boundaries bind `inhibit-field-text-motion' to t.

775 776
This function does not move point.  */)
     (n)
777 778
     Lisp_Object n;
{
779
  int end_pos;
780
  int orig = PT;
781

782 783 784 785 786
  if (NILP (n))
    XSETFASTINT (n, 1);
  else
    CHECK_NUMBER (n, 0);

787 788 789
  end_pos = find_before_next_newline (orig, 0, XINT (n) - (XINT (n) <= 0));

  /* Return END_POS constrained to the current input field.  */
790
  return Fconstrain_to_field (make_number (end_pos), make_number (orig),
791
			      Qnil, Qt, Qnil);
792
}
793

794

Jim Blandy's avatar
Jim Blandy committed
795 796 797
Lisp_Object
save_excursion_save ()
{
798 799
  int visible = (XBUFFER (XWINDOW (selected_window)->buffer)
		 == current_buffer);
Jim Blandy's avatar
Jim Blandy committed
800 801

  return Fcons (Fpoint_marker (),
802
		Fcons (Fcopy_marker (current_buffer->mark, Qnil),
803
		       Fcons (visible ? Qt : Qnil,
804 805
			      Fcons (current_buffer->mark_active,
				     selected_window))));
Jim Blandy's avatar
Jim Blandy committed
806 807 808 809
}

Lisp_Object
save_excursion_restore (info)
810
     Lisp_Object info;
Jim Blandy's avatar
Jim Blandy committed
811
{
812 813
  Lisp_Object tem, tem1, omark, nmark;
  struct gcpro gcpro1, gcpro2, gcpro3;
814
  int visible_p;
Jim Blandy's avatar
Jim Blandy committed
815

816
  tem = Fmarker_buffer (XCAR (info));
Jim Blandy's avatar
Jim Blandy committed
817 818 819 820
  /* If buffer being returned to is now deleted, avoid error */
  /* Otherwise could get error here while unwinding to top level
     and crash */
  /* In that case, Fmarker_buffer returns nil now.  */
Jim Blandy's avatar
Jim Blandy committed
821
  if (NILP (tem))
Jim Blandy's avatar
Jim Blandy committed
822
    return Qnil;
823 824 825 826

  omark = nmark = Qnil;
  GCPRO3 (info, omark, nmark);

Jim Blandy's avatar
Jim Blandy committed
827
  Fset_buffer (tem);
828 829 830

  /* Point marker.  */
  tem = XCAR (info);
Jim Blandy's avatar
Jim Blandy committed
831 832
  Fgoto_char (tem);
  unchain_marker (tem);
833 834 835 836

  /* Mark marker.  */
  info = XCDR (info);
  tem = XCAR (info);
837
  omark = Fmarker_position (current_buffer->mark);
Jim Blandy's avatar
Jim Blandy committed
838
  Fset_marker (current_buffer->mark, tem, Fcurrent_buffer ());
839
  nmark = Fmarker_position (tem);
Jim Blandy's avatar
Jim Blandy committed
840
  unchain_marker (tem);
841 842 843 844 845

  /* visible */
  info = XCDR (info);
  visible_p = !NILP (XCAR (info));
  
846 847 848 849
#if 0 /* We used to make the current buffer visible in the selected window
	 if that was true previously.  That avoids some anomalies.
	 But it creates others, and it wasn't documented, and it is simpler
	 and cleaner never to alter the window/buffer connections.  */
850 851
  tem1 = Fcar (tem);
  if (!NILP (tem1)
852
      && current_buffer != XBUFFER (XWINDOW (selected_window)->buffer))
Jim Blandy's avatar
Jim Blandy committed
853
    Fswitch_to_buffer (Fcurrent_buffer (), Qnil);
854
#endif /* 0 */
855

856 857 858
  /* Mark active */
  info = XCDR (info);
  tem = XCAR (info);
859
  tem1 = current_buffer->mark_active;
860 861
  current_buffer->mark_active = tem;

862 863
  if (!NILP (Vrun_hooks))
    {
864 865
      /* If mark is active now, and either was not active
	 or was at a different place, run the activate hook.  */
866
      if (! NILP (current_buffer->mark_active))
867 868 869 870 871
	{
	  if (! EQ (omark, nmark))
	    call1 (Vrun_hooks, intern ("activate-mark-hook"));
	}
      /* If mark has ceased to be active, run deactivate hook.  */
872 873 874
      else if (! NILP (tem1))
	call1 (Vrun_hooks, intern ("deactivate-mark-hook"));
    }
875 876

  /* If buffer was visible in a window, and a different window was
877 878
     selected, and the old selected window is still showing this
     buffer, restore point in that window.  */
879 880 881
  tem = XCDR (info);
  if (visible_p
      && !EQ (tem, selected_window)
882 883 884 885 886
      && (tem1 = XWINDOW (tem)->buffer,
	  (/* Window is live...  */
	   BUFFERP (tem1)
	   /* ...and it shows the current buffer.  */
	   && XBUFFER (tem1) == current_buffer)))
887 888
    Fset_window_point (tem, make_number (PT));

889
  UNGCPRO;
Jim Blandy's avatar
Jim Blandy committed
890 891 892 893
  return Qnil;
}

DEFUN ("save-excursion", Fsave_excursion, Ssave_excursion, 0, UNEVALLED, 0,
894
       doc: /* Save point, mark, and current buffer; execute BODY; restore those things.
Pavel Janík's avatar
Pavel Janík committed
895 896 897 898 899 900 901 902
Executes BODY just like `progn'.
The values of point, mark and the current buffer are restored
even in case of abnormal exit (throw or error).
The state of activation of the mark is also restored.

This construct does not save `deactivate-mark', and therefore
functions that change the buffer will still cause deactivation
of the mark at the end of the command.  To prevent that, bind
903 904 905
`deactivate-mark' with `let'.

usage: (save-excursion &rest BODY)  */)
906
     (args)
Jim Blandy's avatar
Jim Blandy committed
907 908 909 910 911 912
     Lisp_Object args;
{
  register Lisp_Object val;
  int count = specpdl_ptr - specpdl;

  record_unwind_protect (save_excursion_restore, save_excursion_save ());
913 914 915 916 917 918

  val = Fprogn (args);
  return unbind_to (count, val);
}

DEFUN ("save-current-buffer", Fsave_current_buffer, Ssave_current_buffer, 0, UNEVALLED, 0,
919
       doc: /* Save the current buffer; execute BODY; restore the current buffer.
920 921
Executes BODY just like `progn'.
usage: (save-current-buffer &rest BODY)  */)
922
     (args)
923 924
     Lisp_Object args;
{
925
  Lisp_Object val;
926 927
  int count = specpdl_ptr - specpdl;

928
  record_unwind_protect (set_buffer_if_live, Fcurrent_buffer ());
929

Jim Blandy's avatar
Jim Blandy committed
930 931 932 933
  val = Fprogn (args);
  return unbind_to (count, val);
}

934
DEFUN ("buffer-size", Fbufsize, Sbufsize, 0, 1, 0,
935 936 937
       doc: /* Return the number of characters in the current buffer.
If BUFFER, return the number of characters in that buffer instead.  */)
     (buffer)
938
     Lisp_Object buffer;
Jim Blandy's avatar
Jim Blandy committed
939
{
940 941
  if (NILP (buffer))
    return make_number (Z - BEG);
942 943 944 945 946 947
  else
    {
      CHECK_BUFFER (buffer, 1);
      return make_number (BUF_Z (XBUFFER (buffer))
			  - BUF_BEG (XBUFFER (buffer)));
    }
Jim Blandy's avatar
Jim Blandy committed
948 949 950
}

DEFUN ("point-min", Fpoint_min, Spoint_min, 0, 0, 0,
951 952 953
       doc: /* Return the minimum permissible value of point in the current buffer.
This is 1, unless narrowing (a buffer restriction) is in effect.  */)
     ()
Jim Blandy's avatar
Jim Blandy committed
954 955
{
  Lisp_Object temp;
956
  XSETFASTINT (temp, BEGV);
Jim Blandy's avatar
Jim Blandy committed
957 958 959 960
  return temp;
}

DEFUN ("point-min-marker", Fpoint_min_marker, Spoint_min_marker, 0, 0, 0,
961 962 963
       doc: /* Return a marker to the minimum permissible value of point in this buffer.
This is the beginning, unless narrowing (a buffer restriction) is in effect.  */)
     ()
Jim Blandy's avatar
Jim Blandy committed
964
{
965
  return buildmark (BEGV, BEGV_BYTE);
Jim Blandy's avatar
Jim Blandy committed
966 967 968
}

DEFUN ("point-max", Fpoint_max, Spoint_max, 0, 0, 0,
969
       doc: /* Return the maximum permissible value of point in the current buffer.
Pavel Janík's avatar
Pavel Janík committed
970
This is (1+ (buffer-size)), unless narrowing (a buffer restriction)
971 972
is in effect, in which case it is less.  */)
     ()
Jim Blandy's avatar
Jim Blandy committed
973 974
{
  Lisp_Object temp;
975
  XSETFASTINT (temp, ZV);
Jim Blandy's avatar
Jim Blandy committed
976 977 978 979
  return temp;
}

DEFUN ("point-max-marker", Fpoint_max_marker, Spoint_max_marker, 0, 0, 0,
980
       doc: /* Return a marker to the maximum permissible value of point in this buffer.
Pavel Janík's avatar
Pavel Janík committed
981
This is (1+ (buffer-size)), unless narrowing (a buffer restriction)
982 983
is in effect, in which case it is less.  */)
     ()
Jim Blandy's avatar
Jim Blandy committed
984
{
985
  return buildmark (ZV, ZV_BYTE);
Jim Blandy's avatar
Jim Blandy committed
986 987
}

988
DEFUN ("gap-position", Fgap_position, Sgap_position, 0, 0, 0,
989 990 991
       doc: /* Return the position of the gap, in the current buffer.
See also `gap-size'.  */)
     ()
992 993 994 995 996 997 998
{
  Lisp_Object temp;
  XSETFASTINT (temp, GPT);
  return temp;
}

DEFUN ("gap-size", Fgap_size, Sgap_size, 0, 0, 0,
999 1000 1001
       doc: /* Return the size of the current buffer's gap.
See also `gap-position'.  */)
     ()
1002 1003 1004 1005 1006 1007
{
  Lisp_Object temp;
  XSETFASTINT (temp, GAP_SIZE);
  return temp;
}

1008
DEFUN ("position-bytes", Fposition_bytes, Sposition_bytes, 1, 1, 0,
1009 1010 1011
       doc: /* Return the byte position for character position POSITION.
If POSITION is out of range, the value is nil.  */)
     (position)
1012
     Lisp_Object position;
1013
{
1014
  CHECK_NUMBER_COERCE_MARKER (position, 1);
1015 1016
  if (XINT (position) < BEG || XINT (position) > Z)
    return Qnil;
1017
  return make_number (CHAR_TO_BYTE (XINT (position)));
1018
}
1019 1020

DEFUN ("byte-to-position", Fbyte_to_position, Sbyte_to_position, 1, 1, 0,
1021 1022 1023
       doc: /* Return the character position for byte position BYTEPOS.
If BYTEPOS is out of range, the value is nil.  */)
     (bytepos)
1024 1025 1026
     Lisp_Object bytepos;
{
  CHECK_NUMBER (bytepos, 1);
1027 1028
  if (XINT (bytepos) < BEG_BYTE || XINT (bytepos) > Z_BYTE)
    return Qnil;
1029 1030
  return make_number (BYTE_TO_CHAR (XINT (bytepos)));
}
1031

Jim Blandy's avatar
Jim Blandy committed
1032
DEFUN ("following-char", Ffollowing_char, Sfollowing_char, 0, 0, 0,
1033 1034 1035
       doc: /* Return the character following point, as a number.
At the end of the buffer or accessible region, return 0.  */)
     ()
Jim Blandy's avatar
Jim Blandy committed
1036 1037
{
  Lisp_Object temp;
1038
  if (PT >= ZV)
1039
    XSETFASTINT (temp, 0);
Jim Blandy's avatar
Jim Blandy committed
1040
  else
1041
    XSETFASTINT (temp, FETCH_CHAR (PT_BYTE));
Jim Blandy's avatar
Jim Blandy committed
1042 1043 1044
  return temp;
}

Jim Blandy's avatar
Jim Blandy committed
1045
DEFUN ("preceding-char", Fprevious_char, Sprevious_char, 0, 0, 0,
1046 1047 1048
       doc: /* Return the character preceding point, as a number.
At the beginning of the buffer or accessible region, return 0.  */)
     ()
Jim Blandy's avatar
Jim Blandy committed
1049 1050
{
  Lisp_Object temp;
1051
  if (PT <= BEGV)
1052
    XSETFASTINT (temp, 0);
Karl Heuer's avatar
Karl Heuer committed
1053 1054
  else if (!NILP (current_buffer->enable_multibyte_characters))
    {
1055
      int pos = PT_BYTE;
Karl Heuer's avatar
Karl Heuer committed
1056 1057 1058
      DEC_POS (pos);
      XSETFASTINT (temp, FETCH_CHAR (pos));
    }