editfns.c 118 KB
Newer Older
Jim Blandy's avatar
Jim Blandy committed
1
/* Lisp functions pertaining to editing.
2 3
   Copyright (C) 1985,86,87,89,93,94,95,96,97,98, 1999, 2000
	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>
24
#include <sys/types.h>
Jim Blandy's avatar
Jim Blandy committed
25 26

#ifdef VMS
Jim Blandy's avatar
Jim Blandy committed
27
#include "vms-pwd.h"
Jim Blandy's avatar
Jim Blandy committed
28
#else
Jim Blandy's avatar
Jim Blandy committed
29
#include <pwd.h>
Jim Blandy's avatar
Jim Blandy committed
30 31
#endif

Andreas Schwab's avatar
Andreas Schwab committed
32 33 34 35
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

Jim Blandy's avatar
Jim Blandy committed
36
#include "lisp.h"
37
#include "intervals.h"
Jim Blandy's avatar
Jim Blandy committed
38
#include "buffer.h"
Karl Heuer's avatar
Karl Heuer committed
39
#include "charset.h"
40
#include "coding.h"
Jim Blandy's avatar
Jim Blandy committed
41 42
#include "window.h"

Jim Blandy's avatar
Jim Blandy committed
43
#include "systime.h"
Jim Blandy's avatar
Jim Blandy committed
44 45 46 47

#define min(a, b) ((a) < (b) ? (a) : (b))
#define max(a, b) ((a) > (b) ? (a) : (b))

48 49 50 51
#ifndef NULL
#define NULL 0
#endif

52
#ifndef USE_CRT_DLL
53
extern char **environ;
54 55
#endif

56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72
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));
73 74 75 76

Lisp_Object Vbuffer_access_fontify_functions;
Lisp_Object Qbuffer_access_fontify_functions;
Lisp_Object Vbuffer_access_fontified_property;
77

78
Lisp_Object Fuser_full_name P_ ((Lisp_Object));
79

80 81 82 83
/* 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
84 85 86
/* Some static data, and a function to initialize it for each run */

Lisp_Object Vsystem_name;
87 88 89
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
90

91 92 93 94 95 96 97 98 99
/* 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
100 101 102
void
init_editfns ()
{
Jim Blandy's avatar
Jim Blandy committed
103
  char *user_name;
104
  register unsigned char *p;
Jim Blandy's avatar
Jim Blandy committed
105 106 107 108
  struct passwd *pw;	/* password entry for the current user */
  Lisp_Object tem;

  /* Set up system_name even when dumping.  */
109
  init_system_name ();
Jim Blandy's avatar
Jim Blandy committed
110 111 112 113 114 115 116 117

#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
118 119 120 121
#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.)  */
122
  Vuser_real_login_name = build_string (pw ? pw->pw_name : "root");
Morten Welinder's avatar
Morten Welinder committed
123
#else
124
  Vuser_real_login_name = build_string (pw ? pw->pw_name : "unknown");
Morten Welinder's avatar
Morten Welinder committed
125
#endif
Jim Blandy's avatar
Jim Blandy committed
126

Jim Blandy's avatar
Jim Blandy committed
127 128
  /* Get the effective user name, by consulting environment variables,
     or the effective uid if those are unset.  */
129
  user_name = (char *) getenv ("LOGNAME");
Jim Blandy's avatar
Jim Blandy committed
130
  if (!user_name)
131 132 133
#ifdef WINDOWSNT
    user_name = (char *) getenv ("USERNAME");	/* it's USERNAME on NT */
#else  /* WINDOWSNT */
134
    user_name = (char *) getenv ("USER");
135
#endif /* WINDOWSNT */
Jim Blandy's avatar
Jim Blandy committed
136 137 138 139 140
  if (!user_name)
    {
      pw = (struct passwd *) getpwuid (geteuid ());
      user_name = (char *) (pw ? pw->pw_name : "unknown");
    }
141
  Vuser_login_name = build_string (user_name);
Jim Blandy's avatar
Jim Blandy committed
142

Jim Blandy's avatar
Jim Blandy committed
143 144
  /* If the user name claimed in the environment vars differs from
     the real uid, use the claimed name to find the full name.  */
145
  tem = Fstring_equal (Vuser_login_name, Vuser_real_login_name);
146 147
  Vuser_full_name = Fuser_full_name (NILP (tem)? make_number (geteuid())
				     : Vuser_login_name);
Sam Steingold's avatar
Sam Steingold committed
148

149
  p = (unsigned char *) getenv ("NAME");
150 151
  if (p)
    Vuser_full_name = build_string (p);
152 153
  else if (NILP (Vuser_full_name))
    Vuser_full_name = build_string ("unknown");
Jim Blandy's avatar
Jim Blandy committed
154 155 156
}

DEFUN ("char-to-string", Fchar_to_string, Schar_to_string, 1, 1, 0,
157
  "Convert arg CHAR to a string containing that character.")
158 159
  (character)
     Lisp_Object character;
Jim Blandy's avatar
Jim Blandy committed
160
{
Karl Heuer's avatar
Karl Heuer committed
161
  int len;
162
  unsigned char str[MAX_MULTIBYTE_LENGTH];
Karl Heuer's avatar
Karl Heuer committed
163

164
  CHECK_NUMBER (character, 0);
Jim Blandy's avatar
Jim Blandy committed
165

166
  len = CHAR_STRING (XFASTINT (character), str);
167
  return make_string_from_bytes (str, 1, len);
Jim Blandy's avatar
Jim Blandy committed
168 169 170
}

DEFUN ("string-to-char", Fstring_to_char, Sstring_to_char, 1, 1, 0,
Karl Heuer's avatar
Karl Heuer committed
171 172
  "Convert arg STRING to a character, the first character of that string.\n\
A multibyte character is handled correctly.")
173 174
  (string)
     register Lisp_Object string;
Jim Blandy's avatar
Jim Blandy committed
175 176 177
{
  register Lisp_Object val;
  register struct Lisp_String *p;
178 179
  CHECK_STRING (string, 0);
  p = XSTRING (string);
Jim Blandy's avatar
Jim Blandy committed
180
  if (p->size)
181 182 183 184 185 186
    {
      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
187
  else
188
    XSETFASTINT (val, 0);
Jim Blandy's avatar
Jim Blandy committed
189 190 191 192
  return val;
}

static Lisp_Object
193 194
buildmark (charpos, bytepos)
     int charpos, bytepos;
Jim Blandy's avatar
Jim Blandy committed
195 196 197
{
  register Lisp_Object mark;
  mark = Fmake_marker ();
198
  set_marker_both (mark, Qnil, charpos, bytepos);
Jim Blandy's avatar
Jim Blandy committed
199 200 201 202 203 204 205 206 207
  return mark;
}

DEFUN ("point", Fpoint, Spoint, 0, 0, 0,
  "Return value of point, as an integer.\n\
Beginning of buffer is position (point-min)")
  ()
{
  Lisp_Object temp;
208
  XSETFASTINT (temp, PT);
Jim Blandy's avatar
Jim Blandy committed
209 210 211 212 213 214 215
  return temp;
}

DEFUN ("point-marker", Fpoint_marker, Spoint_marker, 0, 0, 0,
   "Return value of point, as a marker object.")
  ()
{
216
  return buildmark (PT, PT_BYTE);
Jim Blandy's avatar
Jim Blandy committed
217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232
}

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: ",
  "Set point to POSITION, a number or marker.\n\
Karl Heuer's avatar
Karl Heuer committed
233 234 235 236
Beginning of buffer is position (point-min), end is (point-max).\n\
If the position is in the middle of a multibyte form,\n\
the actual point is set at the head of the multibyte form\n\
except in the case that `enable-multibyte-characters' is nil.")
237 238
  (position)
     register Lisp_Object position;
Jim Blandy's avatar
Jim Blandy committed
239
{
Karl Heuer's avatar
Karl Heuer committed
240 241
  int pos;

242 243
  if (MARKERP (position)
      && current_buffer == XMARKER (position)->buffer)
244 245 246 247 248 249 250 251 252 253 254 255
    {
      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;
    }

256
  CHECK_NUMBER_COERCE_MARKER (position, 0);
Jim Blandy's avatar
Jim Blandy committed
257

Karl Heuer's avatar
Karl Heuer committed
258 259
  pos = clip_to_bounds (BEGV, XINT (position), ZV);
  SET_PT (pos);
260
  return position;
Jim Blandy's avatar
Jim Blandy committed
261 262
}

263 264 265 266 267

/* 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
268 269 270 271
static Lisp_Object
region_limit (beginningp)
     int beginningp;
{
272
  extern Lisp_Object Vmark_even_if_inactive; /* Defined in callint.c. */
273 274 275 276
  Lisp_Object m;
  
  if (!NILP (Vtransient_mark_mode)
      && NILP (Vmark_even_if_inactive)
277 278
      && NILP (current_buffer->mark_active))
    Fsignal (Qmark_inactive, Qnil);
279
  
Jim Blandy's avatar
Jim Blandy committed
280
  m = Fmarker_position (current_buffer->mark);
281 282 283
  if (NILP (m))
    error ("There is no region now");
  
284
  if ((PT < XFASTINT (m)) == beginningp)
285 286
    m = make_number (PT);
  return m;
Jim Blandy's avatar
Jim Blandy committed
287 288 289 290 291 292
}

DEFUN ("region-beginning", Fregion_beginning, Sregion_beginning, 0, 0, 0,
  "Return position of beginning of region, as an integer.")
  ()
{
293
  return region_limit (1);
Jim Blandy's avatar
Jim Blandy committed
294 295 296 297 298 299
}

DEFUN ("region-end", Fregion_end, Sregion_end, 0, 0, 0,
  "Return position of end of region, as an integer.")
  ()
{
300
  return region_limit (0);
Jim Blandy's avatar
Jim Blandy committed
301 302 303 304 305 306 307 308 309 310
}

DEFUN ("mark-marker", Fmark_marker, Smark_marker, 0, 0, 0,
  "Return this buffer's mark, as a marker object.\n\
Watch out!  Moving this marker changes the mark position.\n\
If you set the marker not to point anywhere, the buffer will have no mark.")
  ()
{
  return current_buffer->mark;
}
311

312

313 314
/* Return nonzero if POS1 and POS2 have the same value
   for the text property PROP.  */
315 316

static int
317
char_property_eq (prop, pos1, pos2)
318 319 320 321 322
     Lisp_Object prop;
     Lisp_Object pos1, pos2;
{
  Lisp_Object pval1, pval2;

323 324
  pval1 = Fget_char_property (pos1, prop, Qnil);
  pval2 = Fget_char_property (pos2, prop, Qnil);
325 326 327 328

  return EQ (pval1, pval2);
}

329
/* Return the direction from which the char-property PROP would be
330 331 332 333
   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.  */

334
static int
335
char_property_stickiness (prop, pos)
336 337 338 339 340
     Lisp_Object prop;
     Lisp_Object pos;
{
  Lisp_Object front_sticky;

341 342
  if (XINT (pos) > BEGV)
    /* Consider previous character.  */
343 344 345
    {
      Lisp_Object prev_pos, rear_non_sticky;

346
      prev_pos = make_number (XINT (pos) - 1);
347
      rear_non_sticky = Fget_char_property (prev_pos, Qrear_nonsticky, Qnil);
348 349 350

      if (EQ (rear_non_sticky, Qnil)
	  || (CONSP (rear_non_sticky)
351
	      && NILP (Fmemq (prop, rear_non_sticky))))
352
	/* PROP is not rear-non-sticky, and since this takes precedence over
353
	   any front-stickiness, PROP is inherited from before.  */
354 355 356
	return -1;
    }

357
  /* Consider following character.  */
358
  front_sticky = Fget_char_property (pos, Qfront_sticky, Qnil);
359 360 361

  if (EQ (front_sticky, Qt)
      || (CONSP (front_sticky)
362
	  && !NILP (Fmemq (prop, front_sticky))))
363
    /* PROP is inherited from after.  */
364 365
    return 1;

366
  /* PROP is not inherited from either side.  */
367 368
  return 0;
}
369

370

371
/* Find the field surrounding POS in *BEG and *END.  If POS is nil,
372 373
   the value of point is used instead.  If BEG or END null,
   means don't store the beginning or end of the field.
374 375

   If MERGE_AT_BOUNDARY is nonzero, then if POS is at the very first
376 377 378 379 380 381 382 383
   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.
384 385 386 387

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

388
static void
389 390 391 392 393
find_field (pos, merge_at_boundary, beg, end)
     Lisp_Object pos;
     Lisp_Object merge_at_boundary;
     int *beg, *end;
{
394 395
  /* Fields right before and after the point.  */
  Lisp_Object before_field, after_field;
396 397 398 399
  /* 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;
400

401 402 403 404 405
  if (NILP (pos))
    XSETFASTINT (pos, PT);
  else
    CHECK_NUMBER_COERCE_MARKER (pos, 0);

406 407 408 409 410 411
  after_field
    = Fget_char_property (pos, Qfield, Qnil);
  before_field
    = (XFASTINT (pos) > BEGV
       ? Fget_char_property (make_number (XINT (pos) - 1), Qfield, Qnil)
       : Qnil);
412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433

  /* 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.  */
    {
      int stickiness = char_property_stickiness (Qfield, pos);

      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").  */
434
	{
435 436 437 438
	  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.  */
439 440 441
	}
    }

442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463
  /* 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.  */

464
  if (beg)
465 466 467 468 469 470 471 472 473 474 475
    {
      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);
476

477 478 479 480
	  pos = Fprevious_single_char_property_change (pos, Qfield, Qnil, Qnil);
	  *beg = NILP (pos) ? BEGV : XFASTINT (pos);
	}
    }
481 482

  if (end)
483 484 485 486 487 488 489 490 491 492 493
    {
      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);
494

495 496 497 498
	  pos = Fnext_single_char_property_change (pos, Qfield, Qnil, Qnil);
	  *end = NILP (pos) ? ZV : XFASTINT (pos);
	}
    }
499
}
500

501

502
DEFUN ("delete-field", Fdelete_field, Sdelete_field, 0, 1, 0,
503
  "Delete the field surrounding POS.\n\
504
A field is a region of text with the same `field' property.\n\
505
If POS is nil, the value of point is used for POS.")
506 507 508 509 510 511 512
  (pos)
     Lisp_Object pos;
{
  int beg, end;
  find_field (pos, Qnil, &beg, &end);
  if (beg != end)
    del_range (beg, end);
513
  return Qnil;
514 515 516 517 518
}

DEFUN ("field-string", Ffield_string, Sfield_string, 0, 1, 0,
  "Return the contents of the field surrounding POS as a string.\n\
A field is a region of text with the same `field' property.\n\
519
If POS is nil, the value of point is used for POS.")
520 521 522 523 524 525 526 527 528 529 530
  (pos)
     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,
  "Return the contents of the field around POS, without text-properties.\n\
A field is a region of text with the same `field' property.\n\
531
If POS is nil, the value of point is used for POS.")
532 533 534 535 536 537 538 539 540 541 542
  (pos)
     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,
  "Return the beginning of the field surrounding POS.\n\
A field is a region of text with the same `field' property.\n\
543 544
If POS is nil, the value of point is used for POS.\n\
If ESCAPE-FROM-EDGE is non-nil and POS is at the beginning of its\n\
545 546 547 548 549 550 551 552 553 554 555 556
field, then the beginning of the *previous* field is returned.")
  (pos, escape_from_edge)
     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,
  "Return the end of the field surrounding POS.\n\
A field is a region of text with the same `field' property.\n\
557 558
If POS is nil, the value of point is used for POS.\n\
If ESCAPE-FROM-EDGE is non-nil and POS is at the end of its field,\n\
559 560 561 562 563 564 565 566 567
then the end of the *following* field is returned.")
  (pos, escape_from_edge)
     Lisp_Object pos, escape_from_edge;
{
  int end;
  find_field (pos, escape_from_edge, 0, &end);
  return make_number (end);
}

568
DEFUN ("constrain-to-field", Fconstrain_to_field, Sconstrain_to_field, 2, 5, 0,
569
  "Return the position closest to NEW-POS that is in the same field as OLD-POS.\n\
570
\n\
571 572 573 574 575 576 577
A field is a region of text with the same `field' property.\n\
If NEW-POS is nil, then the current point is used instead, and set to the\n\
constrained position if that is is different.\n\
\n\
If OLD-POS is at the boundary of two fields, then the allowable\n\
positions for NEW-POS depends on the value of the optional argument\n\
ESCAPE-FROM-EDGE: If ESCAPE-FROM-EDGE is nil, then NEW-POS is\n\
578
constrained to the field that has the same `field' char-property\n\
579 580
as any new characters inserted at OLD-POS, whereas if ESCAPE-FROM-EDGE\n\
is non-nil, NEW-POS is constrained to the union of the two adjacent\n\
581 582 583
fields.  Additionally, if two fields are separated by another field with\n\
the special value `boundary', then any point within this special field is\n\
also considered to be `on the boundary'.\n\
584 585 586 587 588
\n\
If the optional argument ONLY-IN-LINE is non-nil and constraining\n\
NEW-POS would move it to a different line, NEW-POS is returned\n\
unconstrained.  This useful for commands that move by line, like\n\
\\[next-line] or \\[beginning-of-line], which should generally respect field boundaries\n\
589 590
only in the case where they can still move to the right line.\n\
\n\
591 592 593
If the optional argument INHIBIT-CAPTURE-PROPERTY is non-nil, and OLD-POS has\n\
a non-nil property of that name, then any field boundaries are ignored.\n\
\n\
594
Field boundaries are not noticed if `inhibit-field-text-motion' is non-nil.")
595 596 597
  (new_pos, old_pos, escape_from_edge, only_in_line, inhibit_capture_property)
     Lisp_Object new_pos, old_pos;
     Lisp_Object escape_from_edge, only_in_line, inhibit_capture_property;
598 599 600 601 602 603 604 605 606 607 608
{
  /* 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);
    }

609 610
  if (NILP (Vinhibit_field_text_motion)
      && !EQ (new_pos, old_pos)
611 612 613
      && !char_property_eq (Qfield, new_pos, old_pos)
      && (NILP (inhibit_capture_property)
	  || NILP (Fget_char_property(old_pos, inhibit_capture_property, Qnil))))
614 615 616
    /* NEW_POS is not within the same field as OLD_POS; try to
       move NEW_POS so that it is.  */
    {
617
      int fwd, shortage;
618 619 620 621 622 623 624 625 626 627 628 629
      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);

630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646
      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)))
647 648 649 650 651 652 653 654 655 656
	/* 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;
}
657

658

659 660 661 662 663
DEFUN ("line-beginning-position", Fline_beginning_position, Sline_beginning_position,
  0, 1, 0,
  "Return the character position of the first character on the current line.\n\
With argument N not nil or 1, move forward N - 1 lines first.\n\
If scan reaches end of buffer, return that position.\n\
664
The scan does not cross a field boundary unless it would move\n\
665 666 667 668
beyond there to a different line.  Field boundaries are not noticed if\n\
`inhibit-field-text-motion' is non-nil. .And if N is nil or 1,\n\
and scan starts at a field boundary, the scan stops as soon as it starts.\n\
\n\
669
This function does not move point.")
670 671 672
  (n)
     Lisp_Object n;
{
673
  int orig, orig_byte, end;
674 675 676 677 678 679 680

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

  orig = PT;
681
  orig_byte = PT_BYTE;
682 683
  Fforward_line (make_number (XINT (n) - 1));
  end = PT;
684

685
  SET_PT_BOTH (orig, orig_byte);
Jim Blandy's avatar
Jim Blandy committed
686

687
  /* Return END constrained to the current input field.  */
688 689
  return Fconstrain_to_field (make_number (end), make_number (orig),
			      XINT (n) != 1 ? Qt : Qnil,
690
			      Qt, Qnil);
691 692 693 694 695 696 697 698 699 700 701
}

DEFUN ("line-end-position", Fline_end_position, Sline_end_position,
  0, 1, 0,
  "Return the character position of the last character on the current line.\n\
With argument N not nil or 1, move forward N - 1 lines first.\n\
If scan reaches end of buffer, return that position.\n\
This function does not move point.")
  (n)
     Lisp_Object n;
{
702
  int end_pos;
703
  int orig = PT;
704

705 706 707 708 709
  if (NILP (n))
    XSETFASTINT (n, 1);
  else
    CHECK_NUMBER (n, 0);

710 711 712
  end_pos = find_before_next_newline (orig, 0, XINT (n) - (XINT (n) <= 0));

  /* Return END_POS constrained to the current input field.  */
713
  return Fconstrain_to_field (make_number (end_pos), make_number (orig),
714
			      Qnil, Qt, Qnil);
715 716
}

Jim Blandy's avatar
Jim Blandy committed
717 718 719
Lisp_Object
save_excursion_save ()
{
720 721
  int visible = (XBUFFER (XWINDOW (selected_window)->buffer)
		 == current_buffer);
Jim Blandy's avatar
Jim Blandy committed
722 723

  return Fcons (Fpoint_marker (),
724
		Fcons (Fcopy_marker (current_buffer->mark, Qnil),
725
		       Fcons (visible ? Qt : Qnil,
Sam Steingold's avatar
Sam Steingold committed
726
			      current_buffer->mark_active)));
Jim Blandy's avatar
Jim Blandy committed
727 728 729 730
}

Lisp_Object
save_excursion_restore (info)
731
     Lisp_Object info;
Jim Blandy's avatar
Jim Blandy committed
732
{
733 734
  Lisp_Object tem, tem1, omark, nmark;
  struct gcpro gcpro1, gcpro2, gcpro3;
Jim Blandy's avatar
Jim Blandy committed
735 736 737 738 739 740

  tem = Fmarker_buffer (Fcar (info));
  /* 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
741
  if (NILP (tem))
Jim Blandy's avatar
Jim Blandy committed
742
    return Qnil;
743 744 745 746

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

Jim Blandy's avatar
Jim Blandy committed
747 748 749 750 751
  Fset_buffer (tem);
  tem = Fcar (info);
  Fgoto_char (tem);
  unchain_marker (tem);
  tem = Fcar (Fcdr (info));
752
  omark = Fmarker_position (current_buffer->mark);
Jim Blandy's avatar
Jim Blandy committed
753
  Fset_marker (current_buffer->mark, tem, Fcurrent_buffer ());
754
  nmark = Fmarker_position (tem);
Jim Blandy's avatar
Jim Blandy committed
755 756
  unchain_marker (tem);
  tem = Fcdr (Fcdr (info));
757 758 759 760
#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.  */
761 762
  tem1 = Fcar (tem);
  if (!NILP (tem1)
763
      && current_buffer != XBUFFER (XWINDOW (selected_window)->buffer))
Jim Blandy's avatar
Jim Blandy committed
764
    Fswitch_to_buffer (Fcurrent_buffer (), Qnil);
765
#endif /* 0 */
766 767 768

  tem1 = current_buffer->mark_active;
  current_buffer->mark_active = Fcdr (tem);
769 770
  if (!NILP (Vrun_hooks))
    {
771 772
      /* If mark is active now, and either was not active
	 or was at a different place, run the activate hook.  */
773
      if (! NILP (current_buffer->mark_active))
774 775 776 777 778
	{
	  if (! EQ (omark, nmark))
	    call1 (Vrun_hooks, intern ("activate-mark-hook"));
	}
      /* If mark has ceased to be active, run deactivate hook.  */
779 780 781
      else if (! NILP (tem1))
	call1 (Vrun_hooks, intern ("deactivate-mark-hook"));
    }
782
  UNGCPRO;
Jim Blandy's avatar
Jim Blandy committed
783 784 785 786 787 788 789
  return Qnil;
}

DEFUN ("save-excursion", Fsave_excursion, Ssave_excursion, 0, UNEVALLED, 0,
  "Save point, mark, and current buffer; execute BODY; restore those things.\n\
Executes BODY just like `progn'.\n\
The values of point, mark and the current buffer are restored\n\
790
even in case of abnormal exit (throw or error).\n\
791 792 793 794 795 796
The state of activation of the mark is also restored.\n\
\n\
This construct does not save `deactivate-mark', and therefore\n\
functions that change the buffer will still cause deactivation\n\
of the mark at the end of the command.  To prevent that, bind\n\
`deactivate-mark' with `let'.")
Jim Blandy's avatar
Jim Blandy committed
797 798 799 800 801 802 803
  (args)
     Lisp_Object args;
{
  register Lisp_Object val;
  int count = specpdl_ptr - specpdl;

  record_unwind_protect (save_excursion_restore, save_excursion_save ());
804 805 806 807 808 809 810 811 812 813 814

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

DEFUN ("save-current-buffer", Fsave_current_buffer, Ssave_current_buffer, 0, UNEVALLED, 0,
  "Save the current buffer; execute BODY; restore the current buffer.\n\
Executes BODY just like `progn'.")
  (args)
     Lisp_Object args;
{
815
  Lisp_Object val;
816 817
  int count = specpdl_ptr - specpdl;

818
  record_unwind_protect (set_buffer_if_live, Fcurrent_buffer ());
819

Jim Blandy's avatar
Jim Blandy committed
820 821 822 823
  val = Fprogn (args);
  return unbind_to (count, val);
}

824 825 826 827 828
DEFUN ("buffer-size", Fbufsize, Sbufsize, 0, 1, 0,
  "Return the number of characters in the current buffer.\n\
If BUFFER, return the number of characters in that buffer instead.")
  (buffer)
     Lisp_Object buffer;
Jim Blandy's avatar
Jim Blandy committed
829
{
830 831
  if (NILP (buffer))
    return make_number (Z - BEG);
832 833 834 835 836 837
  else
    {
      CHECK_BUFFER (buffer, 1);
      return make_number (BUF_Z (XBUFFER (buffer))
			  - BUF_BEG (XBUFFER (buffer)));
    }
Jim Blandy's avatar
Jim Blandy committed
838 839 840 841
}

DEFUN ("point-min", Fpoint_min, Spoint_min, 0, 0, 0,
  "Return the minimum permissible value of point in the current buffer.\n\
Richard M. Stallman's avatar
Richard M. Stallman committed
842
This is 1, unless narrowing (a buffer restriction) is in effect.")
Jim Blandy's avatar
Jim Blandy committed
843 844 845
  ()
{
  Lisp_Object temp;
846
  XSETFASTINT (temp, BEGV);
Jim Blandy's avatar
Jim Blandy committed
847 848 849 850 851
  return temp;
}

DEFUN ("point-min-marker", Fpoint_min_marker, Spoint_min_marker, 0, 0, 0,
  "Return a marker to the minimum permissible value of point in this buffer.\n\
Richard M. Stallman's avatar
Richard M. Stallman committed
852
This is the beginning, unless narrowing (a buffer restriction) is in effect.")
Jim Blandy's avatar
Jim Blandy committed
853 854
  ()
{
855
  return buildmark (BEGV, BEGV_BYTE);
Jim Blandy's avatar
Jim Blandy committed
856 857 858 859
}

DEFUN ("point-max", Fpoint_max, Spoint_max, 0, 0, 0,
  "Return the maximum permissible value of point in the current buffer.\n\
Richard M. Stallman's avatar
Richard M. Stallman committed
860 861
This is (1+ (buffer-size)), unless narrowing (a buffer restriction)\n\
is in effect, in which case it is less.")
Jim Blandy's avatar
Jim Blandy committed
862 863 864
  ()
{
  Lisp_Object temp;
865
  XSETFASTINT (temp, ZV);
Jim Blandy's avatar
Jim Blandy committed
866 867 868 869 870
  return temp;
}

DEFUN ("point-max-marker", Fpoint_max_marker, Spoint_max_marker, 0, 0, 0,
  "Return a marker to the maximum permissible value of point in this buffer.\n\
Richard M. Stallman's avatar
Richard M. Stallman committed
871 872
This is (1+ (buffer-size)), unless narrowing (a buffer restriction)\n\
is in effect, in which case it is less.")
Jim Blandy's avatar
Jim Blandy committed
873 874
  ()
{
875
  return buildmark (ZV, ZV_BYTE);
Jim Blandy's avatar
Jim Blandy committed
876 877
}

878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897
DEFUN ("gap-position", Fgap_position, Sgap_position, 0, 0, 0,
  "Return the position of the gap, in the current buffer.\n\
See also `gap-size'.")
  ()
{
  Lisp_Object temp;
  XSETFASTINT (temp, GPT);
  return temp;
}

DEFUN ("gap-size", Fgap_size, Sgap_size, 0, 0, 0,
  "Return the size of the current buffer's gap.\n\
See also `gap-position'.")
  ()
{
  Lisp_Object temp;
  XSETFASTINT (temp, GAP_SIZE);
  return temp;
}

898
DEFUN ("position-bytes", Fposition_bytes, Sposition_bytes, 1, 1, 0,
899 900
  "Return the byte position for character position POSITION.\n\
If POSITION is out of range, the value is nil.")
901
  (position)
902
     Lisp_Object position;
903
{
904
  CHECK_NUMBER_COERCE_MARKER (position, 1);
905 906
  if (XINT (position) < BEG || XINT (position) > Z)
    return Qnil;
907
  return make_number (CHAR_TO_BYTE (XINT (position)));
908
}
909 910

DEFUN ("byte-to-position", Fbyte_to_position, Sbyte_to_position, 1, 1, 0,
911 912
  "Return the character position for byte position BYTEPOS.\n\
If BYTEPOS is out of range, the value is nil.")
913 914 915 916
  (bytepos)
     Lisp_Object bytepos;
{
  CHECK_NUMBER (bytepos, 1);
917 918
  if (XINT (bytepos) < BEG_BYTE || XINT (bytepos) > Z_BYTE)
    return Qnil;
919 920
  return make_number (BYTE_TO_CHAR (XINT (bytepos)));
}
921

Jim Blandy's avatar
Jim Blandy committed
922 923
DEFUN ("following-char", Ffollowing_char, Sfollowing_char, 0, 0, 0,
  "Return the character following point, as a number.\n\
924
At the end of the buffer or accessible region, return 0.")
Jim Blandy's avatar
Jim Blandy committed
925 926 927
  ()
{
  Lisp_Object temp;
928
  if (PT >= ZV)
929
    XSETFASTINT (temp, 0);
Jim Blandy's avatar
Jim Blandy committed
930
  else
931
    XSETFASTINT (temp, FETCH_CHAR (PT_BYTE));
Jim Blandy's avatar
Jim Blandy committed
932 933 934
  return temp;
}

Jim Blandy's avatar
Jim Blandy committed
935 936
DEFUN ("preceding-char", Fprevious_char, Sprevious_char, 0, 0, 0,
  "Return the character preceding point, as a number.\n\
937
At the beginning of the buffer or accessible region, return 0.")
Jim Blandy's avatar
Jim Blandy committed
938 939 940
  ()
{
  Lisp_Object temp;
941
  if (PT <= BEGV)
942
    XSETFASTINT (temp, 0);
Karl Heuer's avatar
Karl Heuer committed
943 944
  else if (!NILP (current_buffer->enable_multibyte_characters))
    {
945
      int pos = PT_BYTE;
Karl Heuer's avatar
Karl Heuer committed
946 947 948
      DEC_POS (pos);
      XSETFASTINT (temp, FETCH_CHAR (pos));
    }
Jim Blandy's avatar
Jim Blandy committed
949
  else
950
    XSETFASTINT (temp, FETCH_BYTE (PT_BYTE - 1));
Jim Blandy's avatar
Jim Blandy committed
951 952 953 954
  return temp;
}

DEFUN ("bobp", Fbobp, Sbobp, 0, 0, 0,
955
  "Return t if point is at the beginning of the buffer.\n\
Jim Blandy's avatar
Jim Blandy committed
956 957 958
If the buffer is narrowed, this means the beginning of the narrowed part.")
  ()
{
959
  if (PT == BEGV)
Jim Blandy's avatar
Jim Blandy committed
960 961 962 963 964
    return Qt;
  return Qnil;
}

DEFUN ("eobp", Feobp, Seobp, 0, 0, 0,
965
  "Return t if point is at the end of the buffer.\n\
Jim Blandy's avatar
Jim Blandy committed
966 967 968
If the buffer is narrowed, this means the end of the narrowed part.")
  ()
{
969
  if (PT == ZV)
Jim Blandy's avatar
Jim Blandy committed
970 971 972 973 974
    return Qt;
  return Qnil;
}

DEFUN ("bolp", Fbolp, Sbolp, 0, 0, 0,
975
  "Return t if point is at the beginning of a line.")
Jim Blandy's avatar
Jim Blandy committed
976 977
  ()
{
978
  if (PT == BEGV || FETCH_BYTE (PT_BYTE - 1) == '\n')
Jim Blandy's avatar
Jim Blandy committed
979 980 981 982 983
    return Qt;
  return Qnil;
}

DEFUN ("eolp", Feolp, Seolp, 0, 0, 0,
984
  "Return t if point is at the end of a line.\n\
Jim Blandy's avatar
Jim Blandy committed
985 986 987
`End of a line' includes point being at the end of the buffer.")
  ()
{
988
  if (PT == ZV || FETCH_BYTE (PT_BYTE) == '\n')
Jim Blandy's avatar
Jim Blandy committed
989 990 991 992
    return Qt;
  return Qnil;
}

993
DEFUN ("char-after", Fchar_after, Schar_after, 0, 1, 0,
Jim Blandy's avatar
Jim Blandy committed
994
  "Return character in current buffer at position POS.\n\
995
POS is an integer or a marker.\n\
996
If POS is out of range, the value is nil.")
Jim Blandy's avatar
Jim Blandy committed
997 998 999
  (pos)
     Lisp_Object pos;
{
1000
  register int pos_byte;
Jim Blandy's avatar
Jim Blandy committed
1001

1002
  if (NILP (pos))
1003 1004
    {
      pos_byte = PT_BYTE;
1005
      XSETFASTINT (pos, PT);
1006 1007 1008
    }

  if (MARKERP (pos))
1009 1010 1011 1012 1013
    {
      pos_byte = marker_byte_position (pos);
      if (pos_byte < BEGV_BYTE || pos_byte >= ZV_BYTE)
	return Qnil;
    }
1014 1015 1016
  else
    {
      CHECK_NUMBER_COERCE_MARKER (pos, 0);
1017
      if (XINT (pos) < BEGV || XINT (pos) >= ZV)
1018
	return Qnil;
Sam Steingold's avatar
Sam Steingold committed
1019

1020
      pos_byte = CHAR_TO_BYTE (XINT (pos));
1021
    }
Jim Blandy's avatar
Jim Blandy committed
1022

1023
  return make_number (FETCH_CHAR (pos_byte));
Jim Blandy's avatar
Jim Blandy committed
1024
}
Karl Heuer's avatar
Karl Heuer committed
1025

1026
DEFUN ("char-before", Fchar_before, Schar_before, 0, 1, 0,
Karl Heuer's avatar
Karl Heuer committed
1027
  "Return character in current buffer preceding position POS.\n\
1028
POS is an integer or a marker.\n\
1029
If POS is out of range, the value is nil.")
Karl Heuer's avatar
Karl Heuer committed
1030 1031 1032 1033
  (pos)
     Lisp_Object pos;
{
  register Lisp_Object val;
1034
  register int pos_byte;
Karl Heuer's avatar
Karl Heuer committed
1035

1036
  if (NILP (pos))
1037 1038
    {
      pos_byte = PT_BYTE;