src/character.h

   1 /* Header for multibyte character handler.
   2    Copyright (C) 1995, 1997, 1998 Electrotechnical Laboratory, JAPAN.
   3      Licensed to the Free Software Foundation.
   4    Copyright (C) 2003
   5      National Institute of Advanced Industrial Science and Technology (AIST)
   6      Registration Number H13PRO009
   7
   8 This file is part of GNU Emacs.
   9
  10 GNU Emacs is free software; you can redistribute it and/or modify
  11 it under the terms of the GNU General Public License as published by
  12 the Free Software Foundation; either version 2, or (at your option)
  13 any later version.
  14
  15 GNU Emacs is distributed in the hope that it will be useful,
  16 but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 GNU General Public License for more details.
  19
  20 You should have received a copy of the GNU General Public License
  21 along with GNU Emacs; see the file COPYING.  If not, write to
  22 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  23 Boston, MA 02111-1307, USA.  */
  24
  25 #ifndef EMACS_CHARACTER_H
  26 #define EMACS_CHARACTER_H
  27
  28 /* character code       1st byte   byte sequence
  29    --------------       --------   -------------
  30         0-7F            00..7F     0xxxxxxx
  31        80-7FF           C2..DF     110xxxxx 10xxxxxx
  32       800-FFFF          E0..EF     1110xxxx 10xxxxxx 10xxxxxx
  33     10000-1FFFFF        F0..F7     11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
  34    200000-3FFF7F        F8         11111000 1000xxxx 10xxxxxx 10xxxxxx 10xxxxxx
  35       invalid           F9..FF
  36
  37    raw-8-bit
  38    3FFF80-3FFFFF        C0..C1     1100000x 10xxxxxx
  39 */
  40
  41 /* Maximum character code ((1 << CHARACTERBITS) - 1).  */
  42 #define MAX_CHAR  0x3FFFFF
  43
  44 /* Maximum Unicode character code.  */
  45 #define MAX_UNICODE_CHAR 0x10FFFF
  46
  47 /* Maximum N-byte character codes.  */
  48 #define MAX_1_BYTE_CHAR 0x7F
  49 #define MAX_2_BYTE_CHAR 0x7FF
  50 #define MAX_3_BYTE_CHAR 0xFFFF
  51 #define MAX_4_BYTE_CHAR 0x1FFFFF
  52 #define MAX_5_BYTE_CHAR 0x3FFF7F
  53
  54 /* Leading code range of Latin-1 chars.  */
  55 #define LEADING_CODE_LATIN_1_MIN 0xC2
  56 #define LEADING_CODE_LATIN_1_MAX 0xC3
  57
  58 /* Nonzero iff C is a character that corresponds to a raw 8-bit
  59    byte.  */
  60 #define CHAR_BYTE8_P(c) ((c) > MAX_5_BYTE_CHAR)
  61
  62 /* Return the character code for raw 8-bit byte BYTE.  */
  63 #define BYTE8_TO_CHAR(byte) ((byte) + 0x3FFF00)
  64
  65 /* Return the raw 8-bit byte for character C.  */
  66 #define CHAR_TO_BYTE8(c)        \
  67   (CHAR_BYTE8_P (c)             \
  68    ? (c) - 0x3FFF00             \
  69    : multibyte_char_to_unibyte (c, Qnil))
  70
  71 /* Nonzero iff BYTE is the 1st byte of a multibyte form of a character
  72    that corresponds to a raw 8-bit byte.  */
  73 #define CHAR_BYTE8_HEAD_P(byte) ((byte) == 0xC0 || (byte) == 0xC1)
  74
  75 /* Mapping table from unibyte chars to multibyte chars.  */
  76 extern int unibyte_to_multibyte_table[256];
  77
  78 /* Convert the unibyte character C to the corresponding multibyte
  79    character.  If C can't be converted, return C.  */
  80 #define unibyte_char_to_multibyte(c)    \
  81   ((c) < 256 ? unibyte_to_multibyte_table[(c)] : (c))
  82
  83 /* If C is not ASCII, make it unibyte. */
  84 #define MAKE_CHAR_UNIBYTE(c)    \
  85   do {                          \
  86     if (! ASCII_CHAR_P (c))     \
  87       c = CHAR_TO_BYTE8 (c);    \
  88   } while (0)
  89
  90
  91 /* If C is not ASCII, make it multibyte.  It assumes C < 256.  */
  92 #define MAKE_CHAR_MULTIBYTE(c) ((c) = unibyte_to_multibyte_table[(c)])
  93
  94 /* This is the maximum byte length of multibyte form.  */
  95 #define MAX_MULTIBYTE_LENGTH 5
  96
  97 /* Return a Lisp character whose character code is C. */
  98 #define make_char(c) make_number (c)
  99
 100 /* Nonzero iff C is an ASCII byte.  */
 101 #define ASCII_BYTE_P(c) ((unsigned) (c) < 0x80)
 102
 103 /* Nonzero iff X is a character.  */
 104 #define CHARACTERP(x) (NATNUMP (x) && XFASTINT (x) <= MAX_CHAR)
 105
 106 /* Nonzero iff C is valid as a character code.  GENERICP is not used
 107    now.  */
 108 #define CHAR_VALID_P(c, genericp) ((unsigned) (c) <= MAX_CHAR)
 109
 110 /* Check if Lisp object X is a character or not.  */
 111 #define CHECK_CHARACTER(x)                                              \
 112   do {                                                                  \
 113     if (! CHARACTERP(x)) x = wrong_type_argument (Qcharacterp, (x));    \
 114   } while (0)
 115
 116 #define CHECK_CHARACTER_CAR(x) \
 117   do {                                  \
 118     Lisp_Object tmp = XCAR (x);         \
 119     CHECK_CHARACTER (tmp);              \
 120     XSETCAR ((x), tmp);                 \
 121   } while (0)
 122
 123 #define CHECK_CHARACTER_CDR(x) \
 124   do {                                  \
 125     Lisp_Object tmp = XCDR (x);         \
 126     CHECK_CHARACTER (tmp);              \
 127     XSETCDR ((x), tmp);                 \
 128   } while (0)
 129
 130 /* Nonzero iff C is an ASCII character.  */
 131 #define ASCII_CHAR_P(c) ((unsigned) (c) < 0x80)
 132
 133 /* Nonzero iff C is a character of code less than 0x100.  */
 134 #define SINGLE_BYTE_CHAR_P(c) ((unsigned) (c) < 0x100)
 135
 136 /* Nonzero if character C has a printable glyph.  */
 137 #define CHAR_PRINTABLE_P(c)     \
 138   (((c) >= 32 && ((c) < 127)    \
 139     || ! NILP (CHAR_TABLE_REF (Vprintable_chars, (c)))))
 140
 141 /* Return byte length of multibyte form for character C.  */
 142 #define CHAR_BYTES(c)                   \
 143   ( (c) <= MAX_1_BYTE_CHAR ? 1          \
 144     : (c) <= MAX_2_BYTE_CHAR ? 2        \
 145     : (c) <= MAX_3_BYTE_CHAR ? 3        \
 146     : (c) <= MAX_4_BYTE_CHAR ? 4        \
 147     : (c) <= MAX_5_BYTE_CHAR ? 5        \
 148     : 2)
 149
 150
 151 /* Return the leading code of multibyte form of C.  */
 152 #define CHAR_LEADING_CODE(c)                            \
 153   ((c) <= MAX_1_BYTE_CHAR ? c                           \
 154    : (c) <= MAX_2_BYTE_CHAR ? (0xC0 | ((c) >> 6))       \
 155    : (c) <= MAX_3_BYTE_CHAR ? (0xE0 | ((c) >> 12))      \
 156    : (c) <= MAX_4_BYTE_CHAR ? (0xF0 | ((c) >> 18))      \
 157    : (c) <= MAX_5_BYTE_CHAR ? 0xF8                      \
 158    : (0xC0 | (((c) >> 6) & 0x01)))
 159
 160
 161 /* Store multibyte form of the character C in P.  The caller should
 162    allocate at least MAX_MULTIBYTE_LENGTH bytes area at P in advance.
 163    Returns the length of the multibyte form.  */
 164
 165 #define CHAR_STRING(c, p)                       \
 166   ((unsigned) (c) <= MAX_1_BYTE_CHAR            \
 167    ? ((p)[0] = (c),                             \
 168       1)                                        \
 169    : (unsigned) (c) <= MAX_2_BYTE_CHAR          \
 170    ? ((p)[0] = (0xC0 | ((c) >> 6)),             \
 171       (p)[1] = (0x80 | ((c) & 0x3F)),           \
 172       2)                                        \
 173    : (unsigned) (c) <= MAX_3_BYTE_CHAR          \
 174    ? ((p)[0] = (0xE0 | ((c) >> 12)),            \
 175       (p)[1] = (0x80 | (((c) >> 6) & 0x3F)),    \
 176       (p)[2] = (0x80 | ((c) & 0x3F)),           \
 177       3)                                        \
 178    : char_string (c, p))
 179
 180 /* Store multibyte form of byte B in P.  The caller should allocate at
 181    least MAX_MULTIBYTE_LENGTH bytes area at P in advance.  Returns the
 182    length of the multibyte form.  */
 183
 184 #define BYTE8_STRING(b, p)                      \
 185   ((p)[0] = (0xC0 | (((b) >> 6) & 0x01)),       \
 186    (p)[1] = (0x80 | ((c) & 0x3F)),              \
 187    2)
 188
 189
 190 /* Store multibyte form of the character C in P.  The caller should
 191    allocate at least MAX_MULTIBYTE_LENGTH bytes area at P in advance.
 192    And, advance P to the end of the multibyte form.  */
 193
 194 #define CHAR_STRING_ADVANCE(c, p)               \
 195   do {                                          \
 196     if ((c) <= MAX_1_BYTE_CHAR)                 \
 197       *(p)++ = (c);                             \
 198     else if ((c) <= MAX_2_BYTE_CHAR)            \
 199       *(p)++ = (0xC0 | ((c) >> 6)),             \
 200         *(p)++ = (0x80 | ((c) & 0x3F));         \
 201     else if ((c) <= MAX_3_BYTE_CHAR)            \
 202       *(p)++ = (0xE0 | ((c) >> 12)),            \
 203         *(p)++ = (0x80 | (((c) >> 6) & 0x3F)),  \
 204         *(p)++ = (0x80 | ((c) & 0x3F));         \
 205     else                                        \
 206       (p) += char_string ((c), (p));            \
 207   } while (0)
 208
 209
 210 /* Nonzero iff BYTE starts a non-ASCII character in a multibyte
 211    form.  */
 212 #define LEADING_CODE_P(byte) (((byte) & 0xC0) == 0xC0)
 213
 214 /* Nonzero iff BYTE is a trailing code of a non-ASCII character in a
 215    multibyte form.  */
 216 #define TRAILING_CODE_P(byte) (((byte) & 0xC0) == 0x80)
 217
 218 /* Nonzero iff BYTE starts a character in a multibyte form.
 219    This is equivalent to:
 220         (ASCII_BYTE_P (byte) || LEADING_CODE_P (byte))  */
 221 #define CHAR_HEAD_P(byte) (((byte) & 0xC0) != 0x80)
 222
 223 /* Just kept for backward compatibility.  This macro will be removed
 224    in the future.  */
 225 #define BASE_LEADING_CODE_P LEADING_CODE_P
 226
 227 /* How many bytes a character that starts with BYTE occupies in a
 228    multibyte form.  */
 229 #define BYTES_BY_CHAR_HEAD(byte)        \
 230   (!((byte) & 0x80) ? 1                 \
 231    : !((byte) & 0x20) ? 2               \
 232    : !((byte) & 0x10) ? 3               \
 233    : !((byte) & 0x08) ? 4               \
 234    : 5)
 235
 236
 237 /* Return the length of the multi-byte form at string STR of length
 238    LEN while assuming that STR points a valid multi-byte form.  As
 239    this macro isn't necessary anymore, all callers will be changed to
 240    use BYTES_BY_CHAR_HEAD directly in the future.  */
 241
 242 #define MULTIBYTE_FORM_LENGTH(str, len)         \
 243   BYTES_BY_CHAR_HEAD (*(str))
 244
 245 /* Parse multibyte string STR of length LENGTH and set BYTES to the
 246    byte length of a character at STR while assuming that STR points a
 247    valid multibyte form.  As this macro isn't necessary anymore, all
 248    callers will be changed to use BYTES_BY_CHAR_HEAD directly in the
 249    future.  */
 250
 251 #define PARSE_MULTIBYTE_SEQ(str, length, bytes) \
 252   (bytes) = BYTES_BY_CHAR_HEAD (*(str))
 253
 254 /* The byte length of multibyte form at unibyte string P ending at
 255    PEND.  If STR doesn't point a valid multibyte form, return 0.  */
 256
 257 #define MULTIBYTE_LENGTH(p, pend)                               \
 258   (p >= pend ? 0                                                \
 259    : !((p)[0] & 0x80) ? 1                                       \
 260    : ((p + 1 >= pend) || (((p)[1] & 0xC0) != 0x80)) ? 0         \
 261    : ((p)[0] & 0xE0) == 0xC0 ? 2                                \
 262    : ((p + 2 >= pend) || (((p)[2] & 0xC0) != 0x80)) ? 0         \
 263    : ((p)[0] & 0xF0) == 0xE0 ? 3                                \
 264    : ((p + 3 >= pend) || (((p)[3] & 0xC0) != 0x80)) ? 0         \
 265    : ((p)[0] & 0xF8) == 0xF0 ? 4                                \
 266    : ((p + 4 >= pend) || (((p)[4] & 0xC0) != 0x80)) ? 0         \
 267    : (p)[0] == 0xF8 && ((p)[1] & 0xF0) == 0x80 ? 5              \
 268    : 0)
 269
 270
 271 /* Like MULTIBYTE_LENGTH but don't check the ending address.  */
 272
 273 #define MULTIBYTE_LENGTH_NO_CHECK(p)                    \
 274   (!((p)[0] & 0x80) ? 1                                 \
 275    : ((p)[1] & 0xC0) != 0x80 ? 0                        \
 276    : ((p)[0] & 0xE0) == 0xC0 ? 2                        \
 277    : ((p)[2] & 0xC0) != 0x80 ? 0                        \
 278    : ((p)[0] & 0xF0) == 0xE0 ? 3                        \
 279    : ((p)[3] & 0xC0) != 0x80 ? 0                        \
 280    : ((p)[0] & 0xF8) == 0xF0 ? 4                        \
 281    : ((p)[4] & 0xC0) != 0x80 ? 0                        \
 282    : (p)[0] == 0xF8 && ((p)[1] & 0xF0) == 0x80 ? 5      \
 283    : 0)
 284
 285 /* If P is before LIMIT, advance P to the next character boundary.  It
 286    assumes that P is already at a character boundary of the sane
 287    mulitbyte form whose end address is LIMIT.  */
 288
 289 #define NEXT_CHAR_BOUNDARY(p, limit)    \
 290   do {                                  \
 291     if ((p) < (limit))                  \
 292       (p) += BYTES_BY_CHAR_HEAD (*(p)); \
 293   } while (0)
 294
 295
 296 /* If P is after LIMIT, advance P to the previous character boundary.
 297    It assumes that P is already at a character boundary of the sane
 298    mulitbyte form whose beginning address is LIMIT.  */
 299
 300 #define PREV_CHAR_BOUNDARY(p, limit)                                    \
 301   do {                                                                  \
 302     if ((p) > (limit))                                                  \
 303       {                                                                 \
 304         const unsigned char *p0 = (p);                                  \
 305         do {                                                            \
 306           p0--;                                                         \
 307         } while (p0 >= limit && ! CHAR_HEAD_P (*p0));                   \
 308         (p) = (BYTES_BY_CHAR_HEAD (*p0) == (p) - p0) ? p0 : (p) - 1;    \
 309       }                                                                 \
 310   } while (0)
 311
 312 /* Return the character code of character whose multibyte form is at
 313    P.  The argument LEN is ignored.  It will be removed in the
 314    future.  */
 315
 316 #define STRING_CHAR(p, len)                                     \
 317   (!((p)[0] & 0x80)                                             \
 318    ? (p)[0]                                                     \
 319    : ! ((p)[0] & 0x20)                                          \
 320    ? (((((p)[0] & 0x1F) << 6)                                   \
 321        | ((p)[1] & 0x3F))                                       \
 322       + (((unsigned char) (p)[0]) < 0xC2 ? 0x3FFF80 : 0))       \
 323    : ! ((p)[0] & 0x10)                                          \
 324    ? ((((p)[0] & 0x0F) << 12)                                   \
 325       | (((p)[1] & 0x3F) << 6)                                  \
 326       | ((p)[2] & 0x3F))                                        \
 327    : string_char ((p), NULL, NULL))
 328
 329
 330 /* Like STRING_CHAR but set ACTUAL_LEN to the length of multibyte
 331    form.  The argument LEN is ignored.  It will be removed in the
 332    future.  */
 333
 334 #define STRING_CHAR_AND_LENGTH(p, len, actual_len)              \
 335   (!((p)[0] & 0x80)                                             \
 336    ? ((actual_len) = 1, (p)[0])                                 \
 337    : ! ((p)[0] & 0x20)                                          \
 338    ? ((actual_len) = 2,                                         \
 339       (((((p)[0] & 0x1F) << 6)                                  \
 340         | ((p)[1] & 0x3F))                                      \
 341        + (((unsigned char) (p)[0]) < 0xC2 ? 0x3FFF80 : 0)))     \
 342    : ! ((p)[0] & 0x10)                                          \
 343    ? ((actual_len) = 3,                                         \
 344       ((((p)[0] & 0x0F) << 12)                                  \
 345        | (((p)[1] & 0x3F) << 6)                                 \
 346        | ((p)[2] & 0x3F)))                                      \
 347    : string_char ((p), NULL, &actual_len))
 348
 349
 350 /* Like STRING_CHAR but advacen P to the end of multibyte form.  */
 351
 352 #define STRING_CHAR_ADVANCE(p)                                  \
 353   (!((p)[0] & 0x80)                                             \
 354    ? *(p)++                                                     \
 355    : ! ((p)[0] & 0x20)                                          \
 356    ? ((p) += 2,                                                 \
 357       ((((p)[-2] & 0x1F) << 6)                                  \
 358        | ((p)[-1] & 0x3F)                                       \
 359        | ((unsigned char) ((p)[-2]) < 0xC2 ? 0x3FFF80 : 0)))    \
 360    : ! ((p)[0] & 0x10)                                          \
 361    ? ((p) += 3,                                                 \
 362       ((((p)[-3] & 0x0F) << 12)                                 \
 363        | (((p)[-2] & 0x3F) << 6)                                \
 364        | ((p)[-1] & 0x3F)))                                     \
 365    : string_char ((p), &(p), NULL))
 366
 367
 368 /* Fetch the "next" character from Lisp string STRING at byte position
 369    BYTEIDX, character position CHARIDX.  Store it into OUTPUT.
 370
 371    All the args must be side-effect-free.
 372    BYTEIDX and CHARIDX must be lvalues;
 373    we increment them past the character fetched.  */
 374
 375 #define FETCH_STRING_CHAR_ADVANCE(OUTPUT, STRING, CHARIDX, BYTEIDX)     \
 376   if (1)                                                                \
 377     {                                                                   \
 378       CHARIDX++;                                                        \
 379       if (STRING_MULTIBYTE (STRING))                                    \
 380         {                                                               \
 381           unsigned char *ptr = &XSTRING (STRING)->data[BYTEIDX];        \
 382           int len;                                                      \
 383                                                                         \
 384           OUTPUT = STRING_CHAR_AND_LENGTH (ptr, 0, len);                \
 385           BYTEIDX += len;                                               \
 386         }                                                               \
 387       else                                                              \
 388         OUTPUT = XSTRING (STRING)->data[BYTEIDX++];                     \
 389     }                                                                   \
 390   else
 391
 392 /* Like FETCH_STRING_CHAR_ADVANCE */
 393
 394 #define FETCH_STRING_CHAR_AS_MULTIBYTE_ADVANCE(OUTPUT, STRING, CHARIDX, BYTEIDX) \
 395   if (1)                                                                      \
 396     {                                                                         \
 397       CHARIDX++;                                                              \
 398       if (STRING_MULTIBYTE (STRING))                                          \
 399         {                                                                     \
 400           unsigned char *ptr = &XSTRING (STRING)->data[BYTEIDX];              \
 401           int len;                                                            \
 402                                                                               \
 403           OUTPUT = STRING_CHAR_AND_LENGTH (ptr, 0, len);                      \
 404           BYTEIDX += len;                                                     \
 405         }                                                                     \
 406       else                                                                    \
 407         {                                                                     \
 408           OUTPUT = XSTRING (STRING)->data[BYTEIDX++];                         \
 409           MAKE_CHAR_MULTIBYTE (OUTPUT);                                       \
 410         }                                                                     \
 411     }                                                                         \
 412   else
 413
 414
 415 /* Like FETCH_STRING_CHAR_ADVANCE but assumes STRING is multibyte.  */
 416
 417 #define FETCH_STRING_CHAR_ADVANCE_NO_CHECK(OUTPUT, STRING, CHARIDX, BYTEIDX) \
 418   if (1)                                                                     \
 419     {                                                                        \
 420       unsigned char *ptr = &XSTRING (STRING)->data[BYTEIDX];                 \
 421       int len;                                                               \
 422                                                                              \
 423       OUTPUT = STRING_CHAR_AND_LENGTH (ptr, 0, len);                         \
 424       BYTEIDX += len;                                                        \
 425       CHARIDX++;                                                             \
 426     }                                                                        \
 427   else
 428
 429
 430 /* Like FETCH_STRING_CHAR_ADVANCE but fetch character from the current
 431    buffer.  */
 432
 433 #define FETCH_CHAR_ADVANCE(OUTPUT, CHARIDX, BYTEIDX)            \
 434   if (1)                                                        \
 435     {                                                           \
 436       CHARIDX++;                                                \
 437       if (!NILP (current_buffer->enable_multibyte_characters))  \
 438         {                                                       \
 439           unsigned char *ptr = BYTE_POS_ADDR (BYTEIDX);         \
 440           int len;                                              \
 441                                                                 \
 442           OUTPUT= STRING_CHAR_AND_LENGTH (ptr, 0, len);         \
 443           BYTEIDX += len;                                       \
 444         }                                                       \
 445       else                                                      \
 446         {                                                       \
 447           OUTPUT = *(BYTE_POS_ADDR (BYTEIDX));                  \
 448           BYTEIDX++;                                            \
 449         }                                                       \
 450     }                                                           \
 451   else
 452
 453
 454 /* Like FETCH_CHAR_ADVANCE but assumes STRING is multibyte.  */
 455
 456 #define FETCH_CHAR_ADVANCE_NO_CHECK(OUTPUT, CHARIDX, BYTEIDX)   \
 457   if (1)                                                        \
 458     {                                                           \
 459       unsigned char *ptr = BYTE_POS_ADDR (BYTEIDX);             \
 460       int len;                                                  \
 461                                                                 \
 462       OUTPUT= STRING_CHAR_AND_LENGTH (ptr, 0, len);             \
 463       BYTEIDX += len;                                           \
 464       CHARIDX++;                                                \
 465     }                                                           \
 466   else
 467
 468
 469 /* Increase the buffer byte position POS_BYTE of the current buffer to
 470    the next character boundary.  No range checking of POS.  */
 471
 472 #define INC_POS(pos_byte)                               \
 473   do {                                                  \
 474     unsigned char *p = BYTE_POS_ADDR (pos_byte);        \
 475     pos_byte += BYTES_BY_CHAR_HEAD (*p);                \
 476   } while (0)
 477
 478
 479 /* Decrease the buffer byte position POS_BYTE of the current buffer to
 480    the previous character boundary.  No range checking of POS.  */
 481
 482 #define DEC_POS(pos_byte)                       \
 483   do {                                          \
 484     unsigned char *p;                           \
 485                                                 \
 486     pos_byte--;                                 \
 487     if (pos_byte < GPT_BYTE)                    \
 488       p = BEG_ADDR + pos_byte - 1;              \
 489     else                                        \
 490       p = BEG_ADDR + GAP_SIZE + pos_byte - 1;   \
 491     while (!CHAR_HEAD_P (*p))                   \
 492       {                                         \
 493         p--;                                    \
 494         pos_byte--;                             \
 495       }                                         \
 496   } while (0)
 497
 498 /* Increment both CHARPOS and BYTEPOS, each in the appropriate way.  */
 499
 500 #define INC_BOTH(charpos, bytepos)                              \
 501   do                                                            \
 502     {                                                           \
 503       (charpos)++;                                              \
 504       if (NILP (current_buffer->enable_multibyte_characters))   \
 505         (bytepos)++;                                            \
 506       else                                                      \
 507         INC_POS ((bytepos));                                    \
 508     }                                                           \
 509   while (0)
 510
 511
 512 /* Decrement both CHARPOS and BYTEPOS, each in the appropriate way.  */
 513
 514 #define DEC_BOTH(charpos, bytepos)                              \
 515   do                                                            \
 516     {                                                           \
 517       (charpos)--;                                              \
 518       if (NILP (current_buffer->enable_multibyte_characters))   \
 519         (bytepos)--;                                            \
 520       else                                                      \
 521         DEC_POS ((bytepos));                                    \
 522     }                                                           \
 523   while (0)
 524
 525
 526 /* Increase the buffer byte position POS_BYTE of the current buffer to
 527    the next character boundary.  This macro relies on the fact that
 528    *GPT_ADDR and *Z_ADDR are always accessible and the values are
 529    '\0'.  No range checking of POS_BYTE.  */
 530
 531 #define BUF_INC_POS(buf, pos_byte)                              \
 532   do {                                                          \
 533     unsigned char *p = BUF_BYTE_ADDRESS (buf, pos_byte);        \
 534     pos_byte += BYTES_BY_CHAR_HEAD (*p);                        \
 535   } while (0)
 536
 537
 538 /* Decrease the buffer byte position POS_BYTE of the current buffer to
 539    the previous character boundary.  No range checking of POS_BYTE.  */
 540
 541 #define BUF_DEC_POS(buf, pos_byte)                                      \
 542   do {                                                                  \
 543     unsigned char *p;                                                   \
 544     pos_byte--;                                                         \
 545     if (pos_byte < BUF_GPT_BYTE (buf))                                  \
 546       p = BUF_BEG_ADDR (buf) + pos_byte - 1;                            \
 547     else                                                                \
 548       p = BUF_BEG_ADDR (buf) + BUF_GAP_SIZE (buf) + pos_byte - 1;       \
 549     while (!CHAR_HEAD_P (*p))                                           \
 550       {                                                                 \
 551         p--;                                                            \
 552         pos_byte--;                                                     \
 553       }                                                                 \
 554   } while (0)
 555
 556
 557 #define MAYBE_UNIFY_CHAR(c)                                     \
 558   if (c > MAX_UNICODE_CHAR                                      \
 559       && CHAR_TABLE_P (Vchar_unify_table))                      \
 560     {                                                           \
 561       Lisp_Object val;                                          \
 562       int unified;                                              \
 563                                                                 \
 564       val = CHAR_TABLE_REF (Vchar_unify_table, c);              \
 565       if (! NILP (val))                                         \
 566         {                                                       \
 567           if (SYMBOLP (val))                                    \
 568             {                                                   \
 569               Funify_charset (val, Qnil, Qnil);                 \
 570               val = CHAR_TABLE_REF (Vchar_unify_table, c);      \
 571             }                                                   \
 572           if ((unified = XINT (val)) >= 0)                      \
 573             c = unified;                                        \
 574         }                                                       \
 575     }                                                           \
 576   else
 577
 578
 579 /* Return the width of ASCII character C.  The width is measured by
 580    how many columns occupied on the screen when displayed in the
 581    current buffer.  */
 582
 583 #define ASCII_CHAR_WIDTH(c)                                             \
 584   (c < 0x20                                                             \
 585    ? (c == '\t'                                                         \
 586       ? XFASTINT (current_buffer->tab_width)                            \
 587       : (c == '\n' ? 0 : (NILP (current_buffer->ctl_arrow) ? 4 : 2)))   \
 588    : (c < 0x7f                                                          \
 589       ? 1                                                               \
 590       : ((NILP (current_buffer->ctl_arrow) ? 4 : 2))))
 591
 592 /* Return the width of character C.  The width is measured by how many
 593    columns occupied on the screen when displayed in the current
 594    buffer.  */
 595
 596 #define CHAR_WIDTH(c)           \
 597   (ASCII_CHAR_P (c)             \
 598    ? ASCII_CHAR_WIDTH (c)       \
 599    : XINT (CHAR_TABLE_REF (Vchar_width_table, c)))
 600
 601 extern int char_resolve_modifier_mask P_ ((int));
 602 extern int char_string P_ ((int, unsigned char *));
 603 extern int string_char P_ ((const unsigned char *,
 604                             const unsigned char **, int *));
 605
 606 extern int translate_char P_ ((Lisp_Object, int c));
 607 extern int char_printable_p P_ ((int c));
 608 extern void parse_str_as_multibyte P_ ((const unsigned char *, int, int *,
 609                                         int *));
 610 extern int parse_str_to_multibyte P_ ((unsigned char *, int));
 611 extern int str_as_multibyte P_ ((unsigned char *, int, int, int *));
 612 extern int str_to_multibyte P_ ((unsigned char *, int, int));
 613 extern int str_as_unibyte P_ ((unsigned char *, int));
 614 extern int strwidth P_ ((unsigned char *, int));
 615 extern int c_string_width P_ ((const unsigned char *, int, int, int *, int *));
 616 extern int lisp_string_width P_ ((Lisp_Object, int, int *, int *));
 617
 618 extern Lisp_Object Vprintable_chars;
 619
 620 extern Lisp_Object Qcharacterp, Qauto_fill_chars;
 621 extern Lisp_Object Vtranslation_table_vector;
 622 extern Lisp_Object Vchar_width_table;
 623 extern Lisp_Object Vchar_direction_table;
 624 extern Lisp_Object Vchar_unify_table;
 625
 626 extern Lisp_Object string_escape_byte8 P_ ((Lisp_Object));
 627
 628 /* Return a translation table of id number ID.  */
 629 #define GET_TRANSLATION_TABLE(id) \
 630   (XCDR(XVECTOR(Vtranslation_table_vector)->contents[(id)]))
 631
 632 /* A char-table for characters which may invoke auto-filling.  */
 633 extern Lisp_Object Vauto_fill_chars;
 634
 635 extern Lisp_Object Vchar_script_table;
 636
 637 /* Copy LEN bytes from FROM to TO.  This macro should be used only
 638    when a caller knows that LEN is short and the obvious copy loop is
 639    faster than calling bcopy which has some overhead.  Copying a
 640    multibyte sequence of a character is the typical case.  */
 641
 642 #define BCOPY_SHORT(from, to, len)              \
 643   do {                                          \
 644     int i = len;                                \
 645     unsigned char *from_p = from, *to_p = to;   \
 646     while (i--) *to_p++ = *from_p++;            \
 647   } while (0)
 648
 649 #define DEFSYM(sym, name)       \
 650   do { (sym) = intern ((name)); staticpro (&(sym)); } while (0)
 651
 652 #endif /* EMACS_CHARACTER_H */