fns.c 68.4 KB
Newer Older
Jim Blandy's avatar
Jim Blandy committed
1
/* Random utility Lisp functions.
Richard M. Stallman's avatar
Richard M. Stallman committed
2
   Copyright (C) 1985, 86, 87, 93, 94, 95, 97, 1998 Free Software Foundation, Inc.
Jim Blandy's avatar
Jim Blandy committed
3 4 5 6 7

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
8
the Free Software Foundation; either version 2, or (at your option)
Jim Blandy's avatar
Jim Blandy committed
9 10 11 12 13 14 15 16 17
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
18 19
the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */
Jim Blandy's avatar
Jim Blandy committed
20 21


22
#include <config.h>
Jim Blandy's avatar
Jim Blandy committed
23 24 25 26 27 28 29 30

/* Note on some machines this defines `vector' as a typedef,
   so make sure we don't use that name in this file.  */
#undef vector
#define vector *****

#include "lisp.h"
#include "commands.h"
31
#include "charset.h"
Jim Blandy's avatar
Jim Blandy committed
32 33

#include "buffer.h"
Jim Blandy's avatar
Jim Blandy committed
34
#include "keyboard.h"
35
#include "intervals.h"
36 37
#include "frame.h"
#include "window.h"
Jim Blandy's avatar
Jim Blandy committed
38

Karl Heuer's avatar
Karl Heuer committed
39 40 41 42
#ifndef NULL
#define NULL (void *)0
#endif

43 44 45 46
/* Nonzero enables use of dialog boxes for questions
   asked by mouse commands.  */
int use_dialog_box;

47 48
extern Lisp_Object Flookup_key ();

49 50 51
extern int minibuffer_auto_raise;
extern Lisp_Object minibuf_window;

52
Lisp_Object Qstring_lessp, Qprovide, Qrequire;
53
Lisp_Object Qyes_or_no_p_history;
54
Lisp_Object Qcursor_in_echo_area;
Karl Heuer's avatar
Karl Heuer committed
55
Lisp_Object Qwidget_type;
Jim Blandy's avatar
Jim Blandy committed
56

57
static int internal_equal ();
58

Jim Blandy's avatar
Jim Blandy committed
59 60 61 62 63 64 65 66
DEFUN ("identity", Fidentity, Sidentity, 1, 1, 0,
  "Return the argument unchanged.")
  (arg)
     Lisp_Object arg;
{
  return arg;
}

67 68 69 70
extern long get_random ();
extern void seed_random ();
extern long time ();

Jim Blandy's avatar
Jim Blandy committed
71 72
DEFUN ("random", Frandom, Srandom, 0, 1, 0,
  "Return a pseudo-random number.\n\
73 74
All integers representable in Lisp are equally likely.\n\
  On most systems, this is 28 bits' worth.\n\
75
With positive integer argument N, return random number in interval [0,N).\n\
Jim Blandy's avatar
Jim Blandy committed
76
With argument t, set the random number seed from the current time and pid.")
77 78
  (n)
     Lisp_Object n;
Jim Blandy's avatar
Jim Blandy committed
79
{
80 81
  EMACS_INT val;
  Lisp_Object lispy_val;
82
  unsigned long denominator;
Jim Blandy's avatar
Jim Blandy committed
83

84
  if (EQ (n, Qt))
85
    seed_random (getpid () + time (NULL));
86
  if (NATNUMP (n) && XFASTINT (n) != 0)
Jim Blandy's avatar
Jim Blandy committed
87
    {
88 89 90 91
      /* Try to take our random number from the higher bits of VAL,
	 not the lower, since (says Gentzel) the low bits of `random'
	 are less random than the higher ones.  We do this by using the
	 quotient rather than the remainder.  At the high end of the RNG
92
	 it's possible to get a quotient larger than n; discarding
93
	 these values eliminates the bias that would otherwise appear
94 95
	 when using a large n.  */
      denominator = ((unsigned long)1 << VALBITS) / XFASTINT (n);
96
      do
97
	val = get_random () / denominator;
98
      while (val >= XFASTINT (n));
Jim Blandy's avatar
Jim Blandy committed
99
    }
100
  else
101
    val = get_random ();
102 103
  XSETINT (lispy_val, val);
  return lispy_val;
Jim Blandy's avatar
Jim Blandy committed
104 105 106 107 108 109
}

/* Random data-structure functions */

DEFUN ("length", Flength, Slength, 1, 1, 0,
  "Return the length of vector, list or string SEQUENCE.\n\
Richard M. Stallman's avatar
Richard M. Stallman committed
110 111 112 113
A byte-code function object is also allowed.\n\
If the string contains multibyte characters, this is not the necessarily\n\
the number of characters in the string; it is the number of bytes.\n\
To get the number of characters, use `chars-in-string'")
114 115
  (sequence)
     register Lisp_Object sequence;
Jim Blandy's avatar
Jim Blandy committed
116 117 118 119 120
{
  register Lisp_Object tail, val;
  register int i;

 retry:
121 122 123 124 125
  if (STRINGP (sequence))
    XSETFASTINT (val, XSTRING (sequence)->size);
  else if (VECTORP (sequence))
    XSETFASTINT (val, XVECTOR (sequence)->size);
  else if (CHAR_TABLE_P (sequence))
Karl Heuer's avatar
Karl Heuer committed
126 127 128
    XSETFASTINT (val, (MIN_CHAR_COMPOSITION
		       + (CHAR_FIELD2_MASK | CHAR_FIELD3_MASK)
		       - 1));
129 130 131 132 133
  else if (BOOL_VECTOR_P (sequence))
    XSETFASTINT (val, XBOOL_VECTOR (sequence)->size);
  else if (COMPILEDP (sequence))
    XSETFASTINT (val, XVECTOR (sequence)->size & PSEUDOVECTOR_SIZE_MASK);
  else if (CONSP (sequence))
Jim Blandy's avatar
Jim Blandy committed
134
    {
135
      for (i = 0, tail = sequence; !NILP (tail); i++)
Jim Blandy's avatar
Jim Blandy committed
136 137 138 139 140
	{
	  QUIT;
	  tail = Fcdr (tail);
	}

141
      XSETFASTINT (val, i);
Jim Blandy's avatar
Jim Blandy committed
142
    }
143
  else if (NILP (sequence))
144
    XSETFASTINT (val, 0);
Jim Blandy's avatar
Jim Blandy committed
145 146
  else
    {
147
      sequence = wrong_type_argument (Qsequencep, sequence);
Jim Blandy's avatar
Jim Blandy committed
148 149
      goto retry;
    }
150
  return val;
Jim Blandy's avatar
Jim Blandy committed
151 152
}

153 154 155 156 157 158 159 160
/* This does not check for quits.  That is safe
   since it must terminate.  */

DEFUN ("safe-length", Fsafe_length, Ssafe_length, 1, 1, 0,
  "Return the length of a list, but avoid error or infinite loop.\n\
This function never gets an error.  If LIST is not really a list,\n\
it returns 0.  If LIST is circular, it returns a finite value\n\
which is at least the number of distinct elements.")
Karl Heuer's avatar
Karl Heuer committed
161
  (list)
162 163 164 165 166 167 168 169 170 171
     Lisp_Object list;
{
  Lisp_Object tail, halftail, length;
  int len = 0;

  /* halftail is used to detect circular lists.  */
  halftail = list;
  for (tail = list; CONSP (tail); tail = XCONS (tail)->cdr)
    {
      if (EQ (tail, halftail) && len != 0)
172
	break;
173
      len++;
174
      if ((len & 1) == 0)
175 176 177 178 179 180 181
	halftail = XCONS (halftail)->cdr;
    }

  XSETINT (length, len);
  return length;
}

182 183 184 185
DEFUN ("string-bytes", Fstring_bytes, Sstring_bytes, 1, 1, 0,
  "Return the number of bytes in STRING.\n\
If STRING is a multibyte string, this is greater than the length of STRING.")
  (string)
186
     Lisp_Object string;
187 188
{
  CHECK_STRING (string, 1);
189
  return make_number (STRING_BYTES (XSTRING (string)));
190 191
}

Jim Blandy's avatar
Jim Blandy committed
192
DEFUN ("string-equal", Fstring_equal, Sstring_equal, 2, 2, 0,
193
  "Return t if two strings have identical contents.\n\
194
Case is significant, but text properties are ignored.\n\
Jim Blandy's avatar
Jim Blandy committed
195 196 197 198
Symbols are also allowed; their print names are used instead.")
  (s1, s2)
     register Lisp_Object s1, s2;
{
199
  if (SYMBOLP (s1))
200
    XSETSTRING (s1, XSYMBOL (s1)->name);
201
  if (SYMBOLP (s2))
202
    XSETSTRING (s2, XSYMBOL (s2)->name);
Jim Blandy's avatar
Jim Blandy committed
203 204 205
  CHECK_STRING (s1, 0);
  CHECK_STRING (s2, 1);

206
  if (XSTRING (s1)->size != XSTRING (s2)->size
207 208
      || STRING_BYTES (XSTRING (s1)) != STRING_BYTES (XSTRING (s2))
      || bcmp (XSTRING (s1)->data, XSTRING (s2)->data, STRING_BYTES (XSTRING (s1))))
Jim Blandy's avatar
Jim Blandy committed
209 210 211 212 213
    return Qnil;
  return Qt;
}

DEFUN ("string-lessp", Fstring_lessp, Sstring_lessp, 2, 2, 0,
214
  "Return t if first arg string is less than second in lexicographic order.\n\
Jim Blandy's avatar
Jim Blandy committed
215 216 217 218 219 220
Case is significant.\n\
Symbols are also allowed; their print names are used instead.")
  (s1, s2)
     register Lisp_Object s1, s2;
{
  register int end;
221
  register int i1, i1_byte, i2, i2_byte;
Jim Blandy's avatar
Jim Blandy committed
222

223
  if (SYMBOLP (s1))
224
    XSETSTRING (s1, XSYMBOL (s1)->name);
225
  if (SYMBOLP (s2))
226
    XSETSTRING (s2, XSYMBOL (s2)->name);
Jim Blandy's avatar
Jim Blandy committed
227 228 229
  CHECK_STRING (s1, 0);
  CHECK_STRING (s2, 1);

230 231 232 233 234
  i1 = i1_byte = i2 = i2_byte = 0;

  end = XSTRING (s1)->size;
  if (end > XSTRING (s2)->size)
    end = XSTRING (s2)->size;
Jim Blandy's avatar
Jim Blandy committed
235

236
  while (i1 < end)
Jim Blandy's avatar
Jim Blandy committed
237
    {
238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253
      /* When we find a mismatch, we must compare the
	 characters, not just the bytes.  */
      int c1, c2;

      if (STRING_MULTIBYTE (s1))
	FETCH_STRING_CHAR_ADVANCE (c1, s1, i1, i1_byte);
      else
	c1 = XSTRING (s1)->data[i1++];

      if (STRING_MULTIBYTE (s2))
	FETCH_STRING_CHAR_ADVANCE (c2, s2, i2, i2_byte);
      else
	c2 = XSTRING (s2)->data[i2++];

      if (c1 != c2)
	return c1 < c2 ? Qt : Qnil;
Jim Blandy's avatar
Jim Blandy committed
254
    }
255
  return i1 < XSTRING (s2)->size ? Qt : Qnil;
Jim Blandy's avatar
Jim Blandy committed
256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274
}

static Lisp_Object concat ();

/* ARGSUSED */
Lisp_Object
concat2 (s1, s2)
     Lisp_Object s1, s2;
{
#ifdef NO_ARG_ARRAY
  Lisp_Object args[2];
  args[0] = s1;
  args[1] = s2;
  return concat (2, args, Lisp_String, 0);
#else
  return concat (2, &s1, Lisp_String, 0);
#endif /* NO_ARG_ARRAY */
}

Richard M. Stallman's avatar
Richard M. Stallman committed
275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290
/* ARGSUSED */
Lisp_Object
concat3 (s1, s2, s3)
     Lisp_Object s1, s2, s3;
{
#ifdef NO_ARG_ARRAY
  Lisp_Object args[3];
  args[0] = s1;
  args[1] = s2;
  args[2] = s3;
  return concat (3, args, Lisp_String, 0);
#else
  return concat (3, &s1, Lisp_String, 0);
#endif /* NO_ARG_ARRAY */
}

Jim Blandy's avatar
Jim Blandy committed
291 292 293 294
DEFUN ("append", Fappend, Sappend, 0, MANY, 0,
  "Concatenate all the arguments and make the result a list.\n\
The result is a list whose elements are the elements of all the arguments.\n\
Each argument may be a list, vector or string.\n\
Richard M. Stallman's avatar
Richard M. Stallman committed
295
The last argument is not copied, just used as the tail of the new list.")
Jim Blandy's avatar
Jim Blandy committed
296 297 298 299 300 301 302 303 304 305
  (nargs, args)
     int nargs;
     Lisp_Object *args;
{
  return concat (nargs, args, Lisp_Cons, 1);
}

DEFUN ("concat", Fconcat, Sconcat, 0, MANY, 0,
  "Concatenate all the arguments and make the result a string.\n\
The result is a string whose elements are the elements of all the arguments.\n\
306 307 308 309 310 311
Each argument may be a string or a list or vector of characters (integers).\n\
\n\
Do not use individual integers as arguments!\n\
The behavior of `concat' in that case will be changed later!\n\
If your program passes an integer as an argument to `concat',\n\
you should change it right away not to do so.")
Jim Blandy's avatar
Jim Blandy committed
312 313 314 315 316 317 318 319 320 321 322 323 324 325 326
  (nargs, args)
     int nargs;
     Lisp_Object *args;
{
  return concat (nargs, args, Lisp_String, 0);
}

DEFUN ("vconcat", Fvconcat, Svconcat, 0, MANY, 0,
  "Concatenate all the arguments and make the result a vector.\n\
The result is a vector whose elements are the elements of all the arguments.\n\
Each argument may be a list, vector or string.")
  (nargs, args)
     int nargs;
     Lisp_Object *args;
{
327
  return concat (nargs, args, Lisp_Vectorlike, 0);
Jim Blandy's avatar
Jim Blandy committed
328 329
}

330 331 332 333
/* Retrun a copy of a sub char table ARG.  The elements except for a
   nested sub char table are not copied.  */
static Lisp_Object
copy_sub_char_table (arg)
334
     Lisp_Object arg;
335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351
{
  Lisp_Object copy = make_sub_char_table (XCHAR_TABLE (arg)->defalt);
  int i;

  /* Copy all the contents.  */
  bcopy (XCHAR_TABLE (arg)->contents, XCHAR_TABLE (copy)->contents,
	 SUB_CHAR_TABLE_ORDINARY_SLOTS * sizeof (Lisp_Object));
  /* Recursively copy any sub char-tables in the ordinary slots.  */
  for (i = 32; i < SUB_CHAR_TABLE_ORDINARY_SLOTS; i++)
    if (SUB_CHAR_TABLE_P (XCHAR_TABLE (arg)->contents[i]))
      XCHAR_TABLE (copy)->contents[i]
	= copy_sub_char_table (XCHAR_TABLE (copy)->contents[i]);

  return copy;
}


Jim Blandy's avatar
Jim Blandy committed
352 353 354 355 356 357 358
DEFUN ("copy-sequence", Fcopy_sequence, Scopy_sequence, 1, 1, 0,
  "Return a copy of a list, vector or string.\n\
The elements of a list or vector are not copied; they are shared\n\
with the original.")
  (arg)
     Lisp_Object arg;
{
Jim Blandy's avatar
Jim Blandy committed
359
  if (NILP (arg)) return arg;
360 361 362

  if (CHAR_TABLE_P (arg))
    {
363
      int i;
364 365
      Lisp_Object copy;

366
      copy = Fmake_char_table (XCHAR_TABLE (arg)->purpose, Qnil);
367
      /* Copy all the slots, including the extra ones.  */
368
      bcopy (XVECTOR (arg)->contents, XVECTOR (copy)->contents,
369 370
	     ((XCHAR_TABLE (arg)->size & PSEUDOVECTOR_SIZE_MASK)
	      * sizeof (Lisp_Object)));
371

372 373 374 375 376
      /* Recursively copy any sub char tables in the ordinary slots
         for multibyte characters.  */
      for (i = CHAR_TABLE_SINGLE_BYTE_SLOTS;
	   i < CHAR_TABLE_ORDINARY_SLOTS; i++)
	if (SUB_CHAR_TABLE_P (XCHAR_TABLE (arg)->contents[i]))
377
	  XCHAR_TABLE (copy)->contents[i]
378
	    = copy_sub_char_table (XCHAR_TABLE (copy)->contents[i]);
379 380 381 382 383 384 385 386

      return copy;
    }

  if (BOOL_VECTOR_P (arg))
    {
      Lisp_Object val;
      int size_in_chars
387
	= (XBOOL_VECTOR (arg)->size + BITS_PER_CHAR - 1) / BITS_PER_CHAR;
388 389 390 391 392 393 394

      val = Fmake_bool_vector (Flength (arg), Qnil);
      bcopy (XBOOL_VECTOR (arg)->data, XBOOL_VECTOR (val)->data,
	     size_in_chars);
      return val;
    }

395
  if (!CONSP (arg) && !VECTORP (arg) && !STRINGP (arg))
Jim Blandy's avatar
Jim Blandy committed
396 397 398 399 400 401 402 403 404 405 406 407 408 409 410
    arg = wrong_type_argument (Qsequencep, arg);
  return concat (1, &arg, CONSP (arg) ? Lisp_Cons : XTYPE (arg), 0);
}

static Lisp_Object
concat (nargs, args, target_type, last_special)
     int nargs;
     Lisp_Object *args;
     enum Lisp_Type target_type;
     int last_special;
{
  Lisp_Object val;
  register Lisp_Object tail;
  register Lisp_Object this;
  int toindex;
411 412 413
  int toindex_byte;
  register int result_len;
  register int result_len_byte;
Jim Blandy's avatar
Jim Blandy committed
414 415 416
  register int argnum;
  Lisp_Object last_tail;
  Lisp_Object prev;
417
  int some_multibyte;
Jim Blandy's avatar
Jim Blandy committed
418 419 420 421 422 423 424 425 426 427

  /* In append, the last arg isn't treated like the others */
  if (last_special && nargs > 0)
    {
      nargs--;
      last_tail = args[nargs];
    }
  else
    last_tail = Qnil;

428
  /* Canonicalize each argument.  */
Jim Blandy's avatar
Jim Blandy committed
429 430 431
  for (argnum = 0; argnum < nargs; argnum++)
    {
      this = args[argnum];
432
      if (!(CONSP (this) || NILP (this) || VECTORP (this) || STRINGP (this)
433
	    || COMPILEDP (this) || BOOL_VECTOR_P (this)))
Jim Blandy's avatar
Jim Blandy committed
434
	{
435
	  if (INTEGERP (this))
436
            args[argnum] = Fnumber_to_string (this);
Jim Blandy's avatar
Jim Blandy committed
437 438 439 440 441
	  else
	    args[argnum] = wrong_type_argument (Qsequencep, this);
	}
    }

442 443 444 445 446 447 448 449
  /* Compute total length in chars of arguments in RESULT_LEN.
     If desired output is a string, also compute length in bytes
     in RESULT_LEN_BYTE, and determine in SOME_MULTIBYTE
     whether the result should be a multibyte string.  */
  result_len_byte = 0;
  result_len = 0;
  some_multibyte = 0;
  for (argnum = 0; argnum < nargs; argnum++)
Jim Blandy's avatar
Jim Blandy committed
450
    {
451
      int len;
Jim Blandy's avatar
Jim Blandy committed
452
      this = args[argnum];
453 454
      len = XFASTINT (Flength (this));
      if (target_type == Lisp_String)
455
	{
456 457
	  /* We must count the number of bytes needed in the string
	     as well as the number of characters.  */
458 459
	  int i;
	  Lisp_Object ch;
460
	  int this_len_byte;
461

462
	  if (VECTORP (this))
463
	    for (i = 0; i < len; i++)
464 465 466 467
	      {
		ch = XVECTOR (this)->contents[i];
		if (! INTEGERP (ch))
		  wrong_type_argument (Qintegerp, ch);
468 469 470 471
		this_len_byte = XFASTINT (Fchar_bytes (ch));
		result_len_byte += this_len_byte;
		if (this_len_byte > 1)
		  some_multibyte = 1;
472
	      }
473 474
	  else if (BOOL_VECTOR_P (this) && XBOOL_VECTOR (this)->size > 0)
	    wrong_type_argument (Qintegerp, Faref (this, make_number (0)));
475
	  else if (CONSP (this))
476 477 478 479 480
	    for (; CONSP (this); this = XCONS (this)->cdr)
	      {
		ch = XCONS (this)->car;
		if (! INTEGERP (ch))
		  wrong_type_argument (Qintegerp, ch);
481 482 483 484
		this_len_byte = XFASTINT (Fchar_bytes (ch));
		result_len_byte += this_len_byte;
		if (this_len_byte > 1)
		  some_multibyte = 1;
485
	      }
486
	  else if (STRINGP (this))
487
	    {
488
	      if (STRING_MULTIBYTE (this))
489 490
		{
		  some_multibyte = 1;
491
		  result_len_byte += STRING_BYTES (XSTRING (this));
492 493 494 495
		}
	      else
		result_len_byte += count_size_as_multibyte (XSTRING (this)->data,
							    XSTRING (this)->size);
496
	    }
497
	}
498 499

      result_len += len;
Jim Blandy's avatar
Jim Blandy committed
500 501
    }

502 503
  if (! some_multibyte)
    result_len_byte = result_len;
Jim Blandy's avatar
Jim Blandy committed
504

505
  /* Create the output object.  */
Jim Blandy's avatar
Jim Blandy committed
506
  if (target_type == Lisp_Cons)
507
    val = Fmake_list (make_number (result_len), Qnil);
508
  else if (target_type == Lisp_Vectorlike)
509
    val = Fmake_vector (make_number (result_len), Qnil);
Jim Blandy's avatar
Jim Blandy committed
510
  else
511
    val = make_uninit_multibyte_string (result_len, result_len_byte);
Jim Blandy's avatar
Jim Blandy committed
512

513 514 515
  /* In `append', if all but last arg are nil, return last arg.  */
  if (target_type == Lisp_Cons && EQ (val, Qnil))
    return last_tail;
Jim Blandy's avatar
Jim Blandy committed
516

517
  /* Copy the contents of the args into the result.  */
Jim Blandy's avatar
Jim Blandy committed
518 519 520
  if (CONSP (val))
    tail = val, toindex = -1;		/* -1 in toindex is flag we are making a list */
  else
521
    toindex = 0, toindex_byte = 0;
Jim Blandy's avatar
Jim Blandy committed
522 523 524 525 526 527 528

  prev = Qnil;

  for (argnum = 0; argnum < nargs; argnum++)
    {
      Lisp_Object thislen;
      int thisleni;
529
      register unsigned int thisindex = 0;
530
      register unsigned int thisindex_byte = 0;
Jim Blandy's avatar
Jim Blandy committed
531 532 533 534 535

      this = args[argnum];
      if (!CONSP (this))
	thislen = Flength (this), thisleni = XINT (thislen);

536
      if (STRINGP (this) && STRINGP (val)
537
	  && ! NULL_INTERVAL_P (XSTRING (this)->intervals))
538 539
	copy_text_properties (make_number (0), thislen, this,
			      make_number (toindex), val, Qnil);
540

541 542 543
      /* Between strings of the same kind, copy fast.  */
      if (STRINGP (this) && STRINGP (val)
	  && STRING_MULTIBYTE (this) == some_multibyte)
Jim Blandy's avatar
Jim Blandy committed
544
	{
545
	  int thislen_byte = STRING_BYTES (XSTRING (this));
546
	  bcopy (XSTRING (this)->data, XSTRING (val)->data + toindex_byte,
547
		 STRING_BYTES (XSTRING (this)));
548 549 550
	  toindex_byte += thislen_byte;
	  toindex += thisleni;
	}
551 552 553 554 555 556 557 558
      /* Copy a single-byte string to a multibyte string.  */
      else if (STRINGP (this) && STRINGP (val))
	{
	  toindex_byte += copy_text (XSTRING (this)->data,
				     XSTRING (val)->data + toindex_byte,
				     XSTRING (this)->size, 0, 1);
	  toindex += thisleni;
	}
559 560 561 562 563 564 565 566 567 568 569
      else
	/* Copy element by element.  */
	while (1)
	  {
	    register Lisp_Object elt;

	    /* Fetch next element of `this' arg into `elt', or break if
	       `this' is exhausted. */
	    if (NILP (this)) break;
	    if (CONSP (this))
	      elt = XCONS (this)->car, this = XCONS (this)->cdr;
570 571 572
	    else if (thisindex >= thisleni)
	      break;
	    else if (STRINGP (this))
573
	      {
574
		int c;
575
		if (STRING_MULTIBYTE (this))
576
		  {
577 578 579 580
		    FETCH_STRING_CHAR_ADVANCE (c, this,
					       thisindex,
					       thisindex_byte);
		    XSETFASTINT (elt, c);
581
		  }
582
		else
583
		  {
584 585 586 587
		    XSETFASTINT (elt, XSTRING (this)->data[thisindex++]);
		    if (some_multibyte && XINT (elt) >= 0200
			&& XINT (elt) < 0400)
		      {
588
			c = unibyte_char_to_multibyte (XINT (elt));
589 590
			XSETINT (elt, c);
		      }
591
		  }
592 593 594 595 596 597 598
	      }
	    else if (BOOL_VECTOR_P (this))
	      {
		int byte;
		byte = XBOOL_VECTOR (this)->data[thisindex / BITS_PER_CHAR];
		if (byte & (1 << (thisindex % BITS_PER_CHAR)))
		  elt = Qt;
599
		else
600 601
		  elt = Qnil;
		thisindex++;
602
	      }
603 604
	    else
	      elt = XVECTOR (this)->contents[thisindex++];
Jim Blandy's avatar
Jim Blandy committed
605

606 607
	    /* Store this element into the result.  */
	    if (toindex < 0)
Jim Blandy's avatar
Jim Blandy committed
608
	      {
609 610 611
		XCONS (tail)->car = elt;
		prev = tail;
		tail = XCONS (tail)->cdr;
Jim Blandy's avatar
Jim Blandy committed
612
	      }
613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639
	    else if (VECTORP (val))
	      XVECTOR (val)->contents[toindex++] = elt;
	    else
	      {
		CHECK_NUMBER (elt, 0);
		if (SINGLE_BYTE_CHAR_P (XINT (elt)))
		  {
		    XSTRING (val)->data[toindex++] = XINT (elt);
		    toindex_byte++;
		  }
		else
		  /* If we have any multibyte characters,
		     we already decided to make a multibyte string.  */
		  {
		    int c = XINT (elt);
		    unsigned char work[4], *str;
		    int i = CHAR_STRING (c, work, str);

		    /* P exists as a variable
		       to avoid a bug on the Masscomp C compiler.  */
		    unsigned char *p = & XSTRING (val)->data[toindex_byte];
		    bcopy (str, p, i);
		    toindex_byte += i;
		    toindex++;
		  }
	      }
	  }
Jim Blandy's avatar
Jim Blandy committed
640
    }
Jim Blandy's avatar
Jim Blandy committed
641
  if (!NILP (prev))
Jim Blandy's avatar
Jim Blandy committed
642 643
    XCONS (prev)->cdr = last_tail;

Karl Heuer's avatar
Karl Heuer committed
644
  return val;
Jim Blandy's avatar
Jim Blandy committed
645 646
}

647 648 649 650
static Lisp_Object string_char_byte_cache_string;
static int string_char_byte_cache_charpos;
static int string_char_byte_cache_bytepos;

651 652 653 654 655 656 657
/* Return the character index corresponding to CHAR_INDEX in STRING.  */

int
string_char_to_byte (string, char_index)
     Lisp_Object string;
     int char_index;
{
658 659 660
  int i, i_byte;
  int best_below, best_below_byte;
  int best_above, best_above_byte;
661 662 663 664

  if (! STRING_MULTIBYTE (string))
    return char_index;

665 666
  best_below = best_below_byte = 0;
  best_above = XSTRING (string)->size;
667
  best_above_byte = STRING_BYTES (XSTRING (string));
668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693

  if (EQ (string, string_char_byte_cache_string))
    {
      if (string_char_byte_cache_charpos < char_index)
	{
	  best_below = string_char_byte_cache_charpos;
	  best_below_byte = string_char_byte_cache_bytepos;
	}
      else
	{
	  best_above = string_char_byte_cache_charpos;
	  best_above_byte = string_char_byte_cache_bytepos;
	}
    }

  if (char_index - best_below < best_above - char_index)
    {
      while (best_below < char_index)
	{
	  int c;
	  FETCH_STRING_CHAR_ADVANCE (c, string, best_below, best_below_byte);
	}
      i = best_below;
      i_byte = best_below_byte;
    }
  else
694
    {
695 696 697 698 699 700 701 702 703 704 705 706 707
      while (best_above > char_index)
	{
	  int best_above_byte_saved = --best_above_byte;

	  while (best_above_byte > 0
		 && !CHAR_HEAD_P (XSTRING (string)->data[best_above_byte]))
	    best_above_byte--;
	  if (XSTRING (string)->data[best_above_byte] < 0x80)
	    best_above_byte = best_above_byte_saved;
	  best_above--;
	}
      i = best_above;
      i_byte = best_above_byte;
708 709
    }

710 711 712 713
  string_char_byte_cache_bytepos = i_byte;
  string_char_byte_cache_charpos = i;
  string_char_byte_cache_string = string;

714 715
  return i_byte;
}
716

717 718 719 720 721 722 723
/* Return the character index corresponding to BYTE_INDEX in STRING.  */

int
string_byte_to_char (string, byte_index)
     Lisp_Object string;
     int byte_index;
{
724 725 726
  int i, i_byte;
  int best_below, best_below_byte;
  int best_above, best_above_byte;
727 728 729 730

  if (! STRING_MULTIBYTE (string))
    return byte_index;

731 732
  best_below = best_below_byte = 0;
  best_above = XSTRING (string)->size;
733
  best_above_byte = STRING_BYTES (XSTRING (string));
734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759

  if (EQ (string, string_char_byte_cache_string))
    {
      if (string_char_byte_cache_bytepos < byte_index)
	{
	  best_below = string_char_byte_cache_charpos;
	  best_below_byte = string_char_byte_cache_bytepos;
	}
      else
	{
	  best_above = string_char_byte_cache_charpos;
	  best_above_byte = string_char_byte_cache_bytepos;
	}
    }

  if (byte_index - best_below_byte < best_above_byte - byte_index)
    {
      while (best_below_byte < byte_index)
	{
	  int c;
	  FETCH_STRING_CHAR_ADVANCE (c, string, best_below, best_below_byte);
	}
      i = best_below;
      i_byte = best_below_byte;
    }
  else
760
    {
761 762 763 764 765 766 767 768 769 770 771 772 773
      while (best_above_byte > byte_index)
	{
	  int best_above_byte_saved = --best_above_byte;

	  while (best_above_byte > 0
		 && !CHAR_HEAD_P (XSTRING (string)->data[best_above_byte]))
	    best_above_byte--;
	  if (XSTRING (string)->data[best_above_byte] < 0x80)
	    best_above_byte = best_above_byte_saved;
	  best_above--;
	}
      i = best_above;
      i_byte = best_above_byte;
774 775
    }

776 777 778 779
  string_char_byte_cache_bytepos = i_byte;
  string_char_byte_cache_charpos = i;
  string_char_byte_cache_string = string;

780 781
  return i;
}
782

783
/* Convert STRING to a multibyte string.
784
   Single-byte characters 0240 through 0377 are converted
785 786 787 788 789 790 791 792 793 794 795 796 797 798
   by adding nonascii_insert_offset to each.  */

Lisp_Object
string_make_multibyte (string)
     Lisp_Object string;
{
  unsigned char *buf;
  int nbytes;

  if (STRING_MULTIBYTE (string))
    return string;

  nbytes = count_size_as_multibyte (XSTRING (string)->data,
				    XSTRING (string)->size);
799 800
  /* If all the chars are ASCII, they won't need any more bytes
     once converted.  In that case, we can return STRING itself.  */
801
  if (nbytes == STRING_BYTES (XSTRING (string)))
802 803
    return string;

804
  buf = (unsigned char *) alloca (nbytes);
805
  copy_text (XSTRING (string)->data, buf, STRING_BYTES (XSTRING (string)),
806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823
	     0, 1);

  return make_multibyte_string (buf, XSTRING (string)->size, nbytes);
}

/* Convert STRING to a single-byte string.  */

Lisp_Object
string_make_unibyte (string)
     Lisp_Object string;
{
  unsigned char *buf;

  if (! STRING_MULTIBYTE (string))
    return string;

  buf = (unsigned char *) alloca (XSTRING (string)->size);

824
  copy_text (XSTRING (string)->data, buf, STRING_BYTES (XSTRING (string)),
825 826 827 828
	     1, 0);

  return make_unibyte_string (buf, XSTRING (string)->size);
}
829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846

DEFUN ("string-make-multibyte", Fstring_make_multibyte, Sstring_make_multibyte,
       1, 1, 0,
  "Return the multibyte equivalent of STRING.")
  (string)
     Lisp_Object string;
{
  return string_make_multibyte (string);
}

DEFUN ("string-make-unibyte", Fstring_make_unibyte, Sstring_make_unibyte,
       1, 1, 0,
  "Return the unibyte equivalent of STRING.")
  (string)
     Lisp_Object string;
{
  return string_make_unibyte (string);
}
847 848 849 850 851 852 853 854 855 856 857

DEFUN ("string-as-unibyte", Fstring_as_unibyte, Sstring_as_unibyte,
       1, 1, 0,
  "Return a unibyte string with the same individual bytes as STRING.\n\
If STRING is unibyte, the result is STRING itself.")
  (string)
     Lisp_Object string;
{
  if (STRING_MULTIBYTE (string))
    {
      string = Fcopy_sequence (string);
858
      XSTRING (string)->size = STRING_BYTES (XSTRING (string));
859 860 861 862 863 864 865 866 867 868 869 870 871
    }
  return string;
}

DEFUN ("string-as-multibyte", Fstring_as_multibyte, Sstring_as_multibyte,
       1, 1, 0,
  "Return a multibyte string with the same individual bytes as STRING.\n\
If STRING is multibyte, the result is STRING itself.")
  (string)
     Lisp_Object string;
{
  if (! STRING_MULTIBYTE (string))
    {
872
      int newlen = multibyte_chars_in_text (XSTRING (string)->data,
873
					    STRING_BYTES (XSTRING (string)));
874
      /* If all the chars are ASCII, STRING is already suitable.  */
875
      if (newlen != STRING_BYTES (XSTRING (string)))
876 877 878 879 880 881 882
	{
	  string = Fcopy_sequence (string);
	  XSTRING (string)->size = newlen;
	}
    }
  return string;
}
883

Jim Blandy's avatar
Jim Blandy committed
884 885 886 887 888 889 890 891 892 893 894 895 896
DEFUN ("copy-alist", Fcopy_alist, Scopy_alist, 1, 1, 0,
  "Return a copy of ALIST.\n\
This is an alist which represents the same mapping from objects to objects,\n\
but does not share the alist structure with ALIST.\n\
The objects mapped (cars and cdrs of elements of the alist)\n\
are shared, however.\n\
Elements of ALIST that are not conses are also shared.")
  (alist)
     Lisp_Object alist;
{
  register Lisp_Object tem;

  CHECK_LIST (alist, 0);
Jim Blandy's avatar
Jim Blandy committed
897
  if (NILP (alist))
Jim Blandy's avatar
Jim Blandy committed
898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913
    return alist;
  alist = concat (1, &alist, Lisp_Cons, 0);
  for (tem = alist; CONSP (tem); tem = XCONS (tem)->cdr)
    {
      register Lisp_Object car;
      car = XCONS (tem)->car;

      if (CONSP (car))
	XCONS (tem)->car = Fcons (XCONS (car)->car, XCONS (car)->cdr);
    }
  return alist;
}

DEFUN ("substring", Fsubstring, Ssubstring, 2, 3, 0,
  "Return a substring of STRING, starting at index FROM and ending before TO.\n\
TO may be nil or omitted; then the substring runs to the end of STRING.\n\
914 915 916
If FROM or TO is negative, it counts from the end.\n\
\n\
This function allows vectors as well as strings.")
Jim Blandy's avatar
Jim Blandy committed
917 918 919 920
  (string, from, to)
     Lisp_Object string;
     register Lisp_Object from, to;
{
921
  Lisp_Object res;
922
  int size;
923 924 925
  int size_byte;
  int from_char, to_char;
  int from_byte, to_byte;
926 927 928

  if (! (STRINGP (string) || VECTORP (string)))
    wrong_type_argument (Qarrayp, string);
929

Jim Blandy's avatar
Jim Blandy committed
930
  CHECK_NUMBER (from, 1);
931 932

  if (STRINGP (string))
933 934
    {
      size = XSTRING (string)->size;
935
      size_byte = STRING_BYTES (XSTRING (string));
936
    }
937 938 939
  else
    size = XVECTOR (string)->size;

Jim Blandy's avatar
Jim Blandy committed
940
  if (NILP (to))
941 942 943 944
    {
      to_char = size;
      to_byte = size_byte;
    }
Jim Blandy's avatar
Jim Blandy committed
945
  else
946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961
    {
      CHECK_NUMBER (to, 2);

      to_char = XINT (to);
      if (to_char < 0)
	to_char += size;

      if (STRINGP (string))
	to_byte = string_char_to_byte (string, to_char);
    }

  from_char = XINT (from);
  if (from_char < 0)
    from_char += size;
  if (STRINGP (string))
    from_byte = string_char_to_byte (string, from_char);
Jim Blandy's avatar
Jim Blandy committed
962

963 964 965
  if (!(0 <= from_char && from_char <= to_char && to_char <= size))
    args_out_of_range_3 (string, make_number (from_char),
			 make_number (to_char));
Jim Blandy's avatar
Jim Blandy committed
966

967 968
  if (STRINGP (string))
    {
969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998
      res = make_multibyte_string (XSTRING (string)->data + from_byte,
				   to_char - from_char, to_byte - from_byte);
      copy_text_properties (from_char, to_char, string,
			    make_number (0), res, Qnil);
    }
  else
    res = Fvector (to_char - from_char,
		   XVECTOR (string)->contents + from_char);

  return res;
}

/* Extract a substring of STRING, giving start and end positions
   both in characters and in bytes.  */

Lisp_Object
substring_both (string, from, from_byte, to, to_byte)
     Lisp_Object string;
     int from, from_byte, to, to_byte;
{
  Lisp_Object res;
  int size;
  int size_byte;

  if (! (STRINGP (string) || VECTORP (string)))
    wrong_type_argument (Qarrayp, string);

  if (STRINGP (string))
    {
      size = XSTRING (string)->size;
999
      size_byte = STRING_BYTES (XSTRING (string));
1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010
    }
  else
    size = XVECTOR (string)->size;

  if (!(0 <= from && from <= to && to <= size))
    args_out_of_range_3 (string, make_number (from), make_number (to));

  if (STRINGP (string))
    {
      res = make_multibyte_string (XSTRING (string)->data + from_byte,
				   to - from, to_byte - from_byte);
1011 1012 1013
      copy_text_properties (from, to, string, make_number (0), res, Qnil);
    }
  else
1014 1015
    res = Fvector (to - from,
		   XVECTOR (string)->contents + from);
Karl Heuer's avatar
Karl Heuer committed
1016

1017
  return res;
Jim Blandy's avatar
Jim Blandy committed
1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028
}

DEFUN ("nthcdr", Fnthcdr, Snthcdr, 2, 2, 0,
  "Take cdr N times on LIST, returns the result.")
  (n, list)
     Lisp_Object n;
     register Lisp_Object list;
{
  register int i, num;
  CHECK_NUMBER (n, 0);
  num = XINT (n);
Jim Blandy's avatar
Jim Blandy committed
1029
  for (i = 0; i < num && !NILP (list); i++)
Jim Blandy's avatar
Jim Blandy committed
1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047
    {
      QUIT;
      list = Fcdr (list);
    }
  return list;
}

DEFUN ("nth", Fnth, Snth, 2, 2, 0,
  "Return the Nth element of LIST.\n\
N counts from zero.  If LIST is not that long, nil is returned.")
  (n, list)
     Lisp_Object n, list;
{
  return Fcar (Fnthcdr (n, list));
}

DEFUN ("elt", Felt, Selt, 2, 2, 0,
  "Return element of SEQUENCE at index N.")
1048 1049
  (sequence, n)
     register Lisp_Object sequence, n;
Jim Blandy's avatar
Jim Blandy committed
1050 1051 1052 1053
{
  CHECK_NUMBER (n, 0);
  while (1)
    {
1054 1055 1056 1057 1058
      if (CONSP (sequence) || NILP (sequence))
	return Fcar (Fnthcdr (n, sequence));
      else if (STRINGP (sequence) || VECTORP (sequence)
	       || BOOL_VECTOR_P (sequence) || CHAR_TABLE_P (sequence))
	return Faref (sequence, n);
Jim Blandy's avatar
Jim Blandy committed
1059
      else
1060
	sequence = wrong_type_argument (Qsequencep, sequence);
Jim Blandy's avatar
Jim Blandy committed
1061 1062 1063 1064
    }
}

DEFUN ("member", Fmember, Smember, 2, 2, 0,
Richard M. Stallman's avatar
Richard M. Stallman committed
1065
  "Return non-nil if ELT is an element of LIST.  Comparison done with `equal'.\n\
Jim Blandy's avatar
Jim Blandy committed
1066 1067 1068 1069 1070 1071
The value is actually the tail of LIST whose car is ELT.")
  (elt, list)
     register Lisp_Object elt;
     Lisp_Object list;
{
  register Lisp_Object tail;
1072
  for (tail = list; !NILP (tail); tail = XCONS (tail)->cdr)
Jim Blandy's avatar
Jim Blandy committed
1073 1074 1075
    {
      register Lisp_Object tem;
      tem = Fcar (tail);
Jim Blandy's avatar
Jim Blandy committed
1076
      if (! NILP (Fequal (elt, tem)))
Jim Blandy's avatar
Jim Blandy committed
1077 1078 1079