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, 2004, 2005, 2006, 2007, 2008, 2009
   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 3 of the License, or
  13 (at your option) 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.  If not, see <http://www.gnu.org/licenses/>.  */
  22
  23 #ifndef EMACS_CHARACTER_H
  24 #define EMACS_CHARACTER_H
  25
  26 /* character code       1st byte   byte sequence
  27    --------------       --------   -------------
  28         0-7F            00..7F     0xxxxxxx
  29        80-7FF           C2..DF     110xxxxx 10xxxxxx
  30       800-FFFF          E0..EF     1110xxxx 10xxxxxx 10xxxxxx
  31     10000-1FFFFF        F0..F7     11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
  32    200000-3FFF7F        F8         11111000 1000xxxx 10xxxxxx 10xxxxxx 10xxxxxx
  33    3FFF80-3FFFFF        C0..C1     1100000x 10xxxxxx (for eight-bit-char)
  34    400000-...           invalid
  35
  36    invalid 1st byte     80..BF     10xxxxxx
  37                         F9..FF     11111xxx (xxx != 000)
  38 */
  39
  40 /* Maximum character code ((1 << CHARACTERBITS) - 1).  */
  41 #define MAX_CHAR  0x3FFFFF
  42
  43 /* Maximum Unicode character code.  */
  44 #define MAX_UNICODE_CHAR 0x10FFFF
  45
  46 /* Maximum N-byte character codes.  */
  47 #define MAX_1_BYTE_CHAR 0x7F
  48 #define MAX_2_BYTE_CHAR 0x7FF
  49 #define MAX_3_BYTE_CHAR 0xFFFF
  50 #define MAX_4_BYTE_CHAR 0x1FFFFF
  51 #define MAX_5_BYTE_CHAR 0x3FFF7F
  52
  53 /* Minimum leading code of multibyte characters.  */
  54 #define MIN_MULTIBYTE_LEADING_CODE 0xC0
  55 /* Maximum leading code of multibyte characters.  */
  56 #define MAX_MULTIBYTE_LEADING_CODE 0xF8
  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 /* Return the raw 8-bit byte for character C,
  72    or -1 if C doesn't correspond to a byte.  */
  73 #define CHAR_TO_BYTE_SAFE(c)    \
  74   (CHAR_BYTE8_P (c)             \
  75    ? (c) - 0x3FFF00             \
  76    : multibyte_char_to_unibyte_safe (c))
  77
  78 /* Nonzero iff BYTE is the 1st byte of a multibyte form of a character
  79    that corresponds to a raw 8-bit byte.  */
  80 #define CHAR_BYTE8_HEAD_P(byte) ((byte) == 0xC0 || (byte) == 0xC1)
  81
  82 /* Mapping table from unibyte chars to multibyte chars.  */
  83 extern int unibyte_to_multibyte_table[256];
  84
  85 /* Convert the unibyte character C to the corresponding multibyte
  86    character.  If C can't be converted, return C.  */
  87 #define unibyte_char_to_multibyte(c)    \
  88   ((c) < 256 ? unibyte_to_multibyte_table[(c)] : (c))
  89
  90 /* If C is not ASCII, make it unibyte. */
  91 #define MAKE_CHAR_UNIBYTE(c)    \
  92   do {                          \
  93     if (! ASCII_CHAR_P (c))     \
  94       c = CHAR_TO_BYTE8 (c);    \
  95   } while (0)
  96
  97
  98 /* If C is not ASCII, make it multibyte.  Assumes C < 256.  */
  99 #define MAKE_CHAR_MULTIBYTE(c) \
 100   (eassert ((c) >= 0 && (c) < 256), (c) = unibyte_to_multibyte_table[(c)])
 101
 102 /* This is the maximum byte length of multibyte form.  */
 103 #define MAX_MULTIBYTE_LENGTH 5
 104
 105 /* Return a Lisp character whose character code is C.  Assumes C is
 106    a valid character code.  */
 107 #define make_char(c) make_number (c)
 108
 109 /* Nonzero iff C is an ASCII byte.  */
 110 #define ASCII_BYTE_P(c) ((unsigned) (c) < 0x80)
 111
 112 /* Nonzero iff X is a character.  */
 113 #define CHARACTERP(x) (NATNUMP (x) && XFASTINT (x) <= MAX_CHAR)
 114
 115 /* Nonzero iff C is valid as a character code.  GENERICP is not used.  */
 116 #define CHAR_VALID_P(c, genericp) ((unsigned) (c) <= MAX_CHAR)
 117
 118 /* Check if Lisp object X is a character or not.  */
 119 #define CHECK_CHARACTER(x) \
 120   CHECK_TYPE (CHARACTERP (x), Qcharacterp, x)
 121
 122 #define CHECK_CHARACTER_CAR(x) \
 123   do {                                  \
 124     Lisp_Object tmp = XCAR (x);         \
 125     CHECK_CHARACTER (tmp);              \
 126     XSETCAR ((x), tmp);                 \
 127   } while (0)
 128
 129 #define CHECK_CHARACTER_CDR(x) \
 130   do {                                  \
 131     Lisp_Object tmp = XCDR (x);         \
 132     CHECK_CHARACTER (tmp);              \
 133     XSETCDR ((x), tmp);                 \
 134   } while (0)
 135
 136 /* Nonzero iff C is an ASCII character.  */
 137 #define ASCII_CHAR_P(c) ((unsigned) (c) < 0x80)
 138
 139 /* Nonzero iff C is a character of code less than 0x100.  */
 140 #define SINGLE_BYTE_CHAR_P(c) ((unsigned) (c) < 0x100)
 141
 142 /* Nonzero if character C has a printable glyph.  */
 143 #define CHAR_PRINTABLE_P(c)     \
 144   (((c) >= 32 && ((c) < 127)    \
 145     || ! NILP (CHAR_TABLE_REF (Vprintable_chars, (c)))))
 146
 147 /* Return byte length of multibyte form for character C.  */
 148 #define CHAR_BYTES(c)                   \
 149   ( (c) <= MAX_1_BYTE_CHAR ? 1          \
 150     : (c) <= MAX_2_BYTE_CHAR ? 2        \
 151     : (c) <= MAX_3_BYTE_CHAR ? 3        \
 152     : (c) <= MAX_4_BYTE_CHAR ? 4        \
 153     : (c) <= MAX_5_BYTE_CHAR ? 5        \
 154     : 2)
 155
 156
 157 /* Return the leading code of multibyte form of C.  */
 158 #define CHAR_LEADING_CODE(c)                            \
 159   ((c) <= MAX_1_BYTE_CHAR ? c                           \
 160    : (c) <= MAX_2_BYTE_CHAR ? (0xC0 | ((c) >> 6))       \
 161    : (c) <= MAX_3_BYTE_CHAR ? (0xE0 | ((c) >> 12))      \
 162    : (c) <= MAX_4_BYTE_CHAR ? (0xF0 | ((c) >> 18))      \
 163    : (c) <= MAX_5_BYTE_CHAR ? 0xF8                      \
 164    : (0xC0 | (((c) >> 6) & 0x01)))
 165
 166
 167 /* Store multibyte form of the character C in P.  The caller should
 168    allocate at least MAX_MULTIBYTE_LENGTH bytes area at P in advance.
 169    Returns the length of the multibyte form.  */
 170
 171 #define CHAR_STRING(c, p)                       \
 172   ((unsigned) (c) <= MAX_1_BYTE_CHAR            \
 173    ? ((p)[0] = (c),                             \
 174       1)                                        \
 175    : (unsigned) (c) <= MAX_2_BYTE_CHAR          \
 176    ? ((p)[0] = (0xC0 | ((c) >> 6)),             \
 177       (p)[1] = (0x80 | ((c) & 0x3F)),           \
 178       2)                                        \
 179    : (unsigned) (c) <= MAX_3_BYTE_CHAR          \
 180    ? ((p)[0] = (0xE0 | ((c) >> 12)),            \
 181       (p)[1] = (0x80 | (((c) >> 6) & 0x3F)),    \
 182       (p)[2] = (0x80 | ((c) & 0x3F)),           \
 183       3)                                        \
 184    : char_string ((unsigned) c, p))
 185
 186 /* Store multibyte form of byte B in P.  The caller should allocate at
 187    least MAX_MULTIBYTE_LENGTH bytes area at P in advance.  Returns the
 188    length of the multibyte form.  */
 189
 190 #define BYTE8_STRING(b, p)                      \
 191   ((p)[0] = (0xC0 | (((b) >> 6) & 0x01)),       \
 192    (p)[1] = (0x80 | ((b) & 0x3F)),              \
 193    2)
 194
 195
 196 /* Store multibyte form of the character C in P and advance P to the
 197    end of the multibyte form.  The caller should allocate at least
 198    MAX_MULTIBYTE_LENGTH bytes area at P in advance.  */
 199
 200 #define CHAR_STRING_ADVANCE(c, p)               \
 201   do {                                          \
 202     if ((c) <= MAX_1_BYTE_CHAR)                 \
 203       *(p)++ = (c);                             \
 204     else if ((c) <= MAX_2_BYTE_CHAR)            \
 205       *(p)++ = (0xC0 | ((c) >> 6)),             \
 206         *(p)++ = (0x80 | ((c) & 0x3F));         \
 207     else if ((c) <= MAX_3_BYTE_CHAR)            \
 208       *(p)++ = (0xE0 | ((c) >> 12)),            \
 209         *(p)++ = (0x80 | (((c) >> 6) & 0x3F)),  \
 210         *(p)++ = (0x80 | ((c) & 0x3F));         \
 211     else                                        \
 212       (p) += char_string ((c), (p));            \
 213   } while (0)
 214
 215
 216 /* Nonzero iff BYTE starts a non-ASCII character in a multibyte
 217    form.  */
 218 #define LEADING_CODE_P(byte) (((byte) & 0xC0) == 0xC0)
 219
 220 /* Nonzero iff BYTE is a trailing code of a non-ASCII character in a
 221    multibyte form.  */
 222 #define TRAILING_CODE_P(byte) (((byte) & 0xC0) == 0x80)
 223
 224 /* Nonzero iff BYTE starts a character in a multibyte form.
 225    This is equivalent to:
 226         (ASCII_BYTE_P (byte) || LEADING_CODE_P (byte))  */
 227 #define CHAR_HEAD_P(byte) (((byte) & 0xC0) != 0x80)
 228
 229 /* Kept for backward compatibility.  This macro will be removed in the
 230    future.  */
 231 #define BASE_LEADING_CODE_P LEADING_CODE_P
 232
 233 /* How many bytes a character that starts with BYTE occupies in a
 234    multibyte form.  */
 235 #define BYTES_BY_CHAR_HEAD(byte)        \
 236   (!((byte) & 0x80) ? 1                 \
 237    : !((byte) & 0x20) ? 2               \
 238    : !((byte) & 0x10) ? 3               \
 239    : !((byte) & 0x08) ? 4               \
 240    : 5)
 241
 242
 243 /* Return the length of the multi-byte form at string STR of length
 244    LEN while assuming that STR points a valid multi-byte form.  As
 245    this macro isn't necessary anymore, all callers will be changed to
 246    use BYTES_BY_CHAR_HEAD directly in the future.  */
 247
 248 #define MULTIBYTE_FORM_LENGTH(str, len)         \
 249   BYTES_BY_CHAR_HEAD (*(str))
 250
 251 /* Parse multibyte string STR of length LENGTH and set BYTES to the
 252    byte length of a character at STR while assuming that STR points a
 253    valid multibyte form.  As this macro isn't necessary anymore, all
 254    callers will be changed to use BYTES_BY_CHAR_HEAD directly in the
 255    future.  */
 256
 257 #define PARSE_MULTIBYTE_SEQ(str, length, bytes) \
 258   (bytes) = BYTES_BY_CHAR_HEAD (*(str))
 259
 260 /* The byte length of multibyte form at unibyte string P ending at
 261    PEND.  If STR doesn't point to a valid multibyte form, return 0.  */
 262
 263 #define MULTIBYTE_LENGTH(p, pend)                               \
 264   (p >= pend ? 0                                                \
 265    : !((p)[0] & 0x80) ? 1                                       \
 266    : ((p + 1 >= pend) || (((p)[1] & 0xC0) != 0x80)) ? 0         \
 267    : ((p)[0] & 0xE0) == 0xC0 ? 2                                \
 268    : ((p + 2 >= pend) || (((p)[2] & 0xC0) != 0x80)) ? 0         \
 269    : ((p)[0] & 0xF0) == 0xE0 ? 3                                \
 270    : ((p + 3 >= pend) || (((p)[3] & 0xC0) != 0x80)) ? 0         \
 271    : ((p)[0] & 0xF8) == 0xF0 ? 4                                \
 272    : ((p + 4 >= pend) || (((p)[4] & 0xC0) != 0x80)) ? 0         \
 273    : (p)[0] == 0xF8 && ((p)[1] & 0xF0) == 0x80 ? 5              \
 274    : 0)
 275
 276
 277 /* Like MULTIBYTE_LENGTH, but don't check the ending address.  */
 278
 279 #define MULTIBYTE_LENGTH_NO_CHECK(p)                    \
 280   (!((p)[0] & 0x80) ? 1                                 \
 281    : ((p)[1] & 0xC0) != 0x80 ? 0                        \
 282    : ((p)[0] & 0xE0) == 0xC0 ? 2                        \
 283    : ((p)[2] & 0xC0) != 0x80 ? 0                        \
 284    : ((p)[0] & 0xF0) == 0xE0 ? 3                        \
 285    : ((p)[3] & 0xC0) != 0x80 ? 0                        \
 286    : ((p)[0] & 0xF8) == 0xF0 ? 4                        \
 287    : ((p)[4] & 0xC0) != 0x80 ? 0                        \
 288    : (p)[0] == 0xF8 && ((p)[1] & 0xF0) == 0x80 ? 5      \
 289    : 0)
 290
 291 /* If P is before LIMIT, advance P to the next character boundary.
 292    Assumes that P is already at a character boundary of the same
 293    mulitbyte form whose end address is LIMIT.  */
 294
 295 #define NEXT_CHAR_BOUNDARY(p, limit)    \
 296   do {                                  \
 297     if ((p) < (limit))                  \
 298       (p) += BYTES_BY_CHAR_HEAD (*(p)); \
 299   } while (0)
 300
 301
 302 /* If P is after LIMIT, advance P to the previous character boundary.
 303    Assumes that P is already at a character boundary of the same
 304    mulitbyte form whose beginning address is LIMIT.  */
 305
 306 #define PREV_CHAR_BOUNDARY(p, limit)                                    \
 307   do {                                                                  \
 308     if ((p) > (limit))                                                  \
 309       {                                                                 \
 310         const unsigned char *p0 = (p);                                  \
 311         do {                                                            \
 312           p0--;                                                         \
 313         } while (p0 >= limit && ! CHAR_HEAD_P (*p0));                   \
 314         (p) = (BYTES_BY_CHAR_HEAD (*p0) == (p) - p0) ? p0 : (p) - 1;    \
 315       }                                                                 \
 316   } while (0)
 317
 318 /* Return the character code of character whose multibyte form is at
 319    P.  The argument LEN is ignored.  It will be removed in the
 320    future.  */
 321
 322 #define STRING_CHAR(p, len)                                     \
 323   (!((p)[0] & 0x80)                                             \
 324    ? (p)[0]                                                     \
 325    : ! ((p)[0] & 0x20)                                          \
 326    ? (((((p)[0] & 0x1F) << 6)                                   \
 327        | ((p)[1] & 0x3F))                                       \
 328       + (((unsigned char) (p)[0]) < 0xC2 ? 0x3FFF80 : 0))       \
 329    : ! ((p)[0] & 0x10)                                          \
 330    ? ((((p)[0] & 0x0F) << 12)                                   \
 331       | (((p)[1] & 0x3F) << 6)                                  \
 332       | ((p)[2] & 0x3F))                                        \
 333    : string_char ((p), NULL, NULL))
 334
 335
 336 /* Like STRING_CHAR, but set ACTUAL_LEN to the length of multibyte
 337    form.  The argument LEN is ignored.  It will be removed in the
 338    future.  */
 339
 340 #define STRING_CHAR_AND_LENGTH(p, len, actual_len)              \
 341   (!((p)[0] & 0x80)                                             \
 342    ? ((actual_len) = 1, (p)[0])                                 \
 343    : ! ((p)[0] & 0x20)                                          \
 344    ? ((actual_len) = 2,                                         \
 345       (((((p)[0] & 0x1F) << 6)                                  \
 346         | ((p)[1] & 0x3F))                                      \
 347        + (((unsigned char) (p)[0]) < 0xC2 ? 0x3FFF80 : 0)))     \
 348    : ! ((p)[0] & 0x10)                                          \
 349    ? ((actual_len) = 3,                                         \
 350       ((((p)[0] & 0x0F) << 12)                                  \
 351        | (((p)[1] & 0x3F) << 6)                                 \
 352        | ((p)[2] & 0x3F)))                                      \
 353    : string_char ((p), NULL, &actual_len))
 354
 355
 356 /* Like STRING_CHAR, but advance P to the end of multibyte form.  */
 357
 358 #define STRING_CHAR_ADVANCE(p)                                  \
 359   (!((p)[0] & 0x80)                                             \
 360    ? *(p)++                                                     \
 361    : ! ((p)[0] & 0x20)                                          \
 362    ? ((p) += 2,                                                 \
 363       ((((p)[-2] & 0x1F) << 6)                                  \
 364        | ((p)[-1] & 0x3F)                                       \
 365        | ((unsigned char) ((p)[-2]) < 0xC2 ? 0x3FFF80 : 0)))    \
 366    : ! ((p)[0] & 0x10)                                          \
 367    ? ((p) += 3,                                                 \
 368       ((((p)[-3] & 0x0F) << 12)                                 \
 369        | (((p)[-2] & 0x3F) << 6)                                \
 370        | ((p)[-1] & 0x3F)))                                     \
 371    : string_char ((p), &(p), NULL))
 372
 373
 374 /* Fetch the "next" character from Lisp string STRING at byte position
 375    BYTEIDX, character position CHARIDX.  Store it into OUTPUT.
 376
 377    All the args must be side-effect-free.
 378    BYTEIDX and CHARIDX must be lvalues;
 379    we increment them past the character fetched.  */
 380
 381 #define FETCH_STRING_CHAR_ADVANCE(OUTPUT, STRING, CHARIDX, BYTEIDX)     \
 382   do                                                                    \
 383     {                                                                   \
 384       CHARIDX++;                                                        \
 385       if (STRING_MULTIBYTE (STRING))                                    \
 386         {                                                               \
 387           unsigned char *ptr = &SDATA (STRING)[BYTEIDX];                \
 388           int len;                                                      \
 389                                                                         \
 390           OUTPUT = STRING_CHAR_AND_LENGTH (ptr, 0, len);                \
 391           BYTEIDX += len;                                               \
 392         }                                                               \
 393       else                                                              \
 394         {                                                               \
 395           OUTPUT = SREF (STRING, BYTEIDX);                              \
 396           BYTEIDX++;                                                    \
 397         }                                                               \
 398     }                                                                   \
 399   while (0)
 400
 401 /* Like FETCH_STRING_CHAR_ADVANCE, but return a multibyte character
 402    even if STRING is unibyte.  */
 403
 404 #define FETCH_STRING_CHAR_AS_MULTIBYTE_ADVANCE(OUTPUT, STRING, CHARIDX, BYTEIDX) \
 405   do                                                                          \
 406     {                                                                         \
 407       CHARIDX++;                                                              \
 408       if (STRING_MULTIBYTE (STRING))                                          \
 409         {                                                                     \
 410           unsigned char *ptr = &SDATA (STRING)[BYTEIDX];                      \
 411           int len;                                                            \
 412                                                                               \
 413           OUTPUT = STRING_CHAR_AND_LENGTH (ptr, 0, len);                      \
 414           BYTEIDX += len;                                                     \
 415         }                                                                     \
 416       else                                                                    \
 417         {                                                                     \
 418           OUTPUT = SREF (STRING, BYTEIDX);                                    \
 419           BYTEIDX++;                                                          \
 420           MAKE_CHAR_MULTIBYTE (OUTPUT);                                       \
 421         }                                                                     \
 422     }                                                                         \
 423   while (0)
 424
 425
 426 /* Like FETCH_STRING_CHAR_ADVANCE, but assumes STRING is multibyte.  */
 427
 428 #define FETCH_STRING_CHAR_ADVANCE_NO_CHECK(OUTPUT, STRING, CHARIDX, BYTEIDX) \
 429   do                                                                         \
 430     {                                                                        \
 431       unsigned char *ptr = &SDATA (STRING)[BYTEIDX];                         \
 432       int len;                                                               \
 433                                                                              \
 434       OUTPUT = STRING_CHAR_AND_LENGTH (ptr, 0, len);                         \
 435       BYTEIDX += len;                                                        \
 436       CHARIDX++;                                                             \
 437     }                                                                        \
 438   while (0)
 439
 440
 441 /* Like FETCH_STRING_CHAR_ADVANCE, but fetch character from the current
 442    buffer.  */
 443
 444 #define FETCH_CHAR_ADVANCE(OUTPUT, CHARIDX, BYTEIDX)            \
 445   do                                                            \
 446     {                                                           \
 447       CHARIDX++;                                                \
 448       if (!NILP (current_buffer->enable_multibyte_characters))  \
 449         {                                                       \
 450           unsigned char *ptr = BYTE_POS_ADDR (BYTEIDX);         \
 451           int len;                                              \
 452                                                                 \
 453           OUTPUT= STRING_CHAR_AND_LENGTH (ptr, 0, len);         \
 454           BYTEIDX += len;                                       \
 455         }                                                       \
 456       else                                                      \
 457         {                                                       \
 458           OUTPUT = *(BYTE_POS_ADDR (BYTEIDX));                  \
 459           BYTEIDX++;                                            \
 460         }                                                       \
 461     }                                                           \
 462   while (0)
 463
 464
 465 /* Like FETCH_CHAR_ADVANCE, but assumes the current buffer is multibyte.  */
 466
 467 #define FETCH_CHAR_ADVANCE_NO_CHECK(OUTPUT, CHARIDX, BYTEIDX)   \
 468   do                                                            \
 469     {                                                           \
 470       unsigned char *ptr = BYTE_POS_ADDR (BYTEIDX);             \
 471       int len;                                                  \
 472                                                                 \
 473       OUTPUT= STRING_CHAR_AND_LENGTH (ptr, 0, len);             \
 474       BYTEIDX += len;                                           \
 475       CHARIDX++;                                                \
 476     }                                                           \
 477   while (0)
 478
 479
 480 /* Increment the buffer byte position POS_BYTE of the current buffer to
 481    the next character boundary.  No range checking of POS.  */
 482
 483 #define INC_POS(pos_byte)                               \
 484   do {                                                  \
 485     unsigned char *p = BYTE_POS_ADDR (pos_byte);        \
 486     pos_byte += BYTES_BY_CHAR_HEAD (*p);                \
 487   } while (0)
 488
 489
 490 /* Decrement the buffer byte position POS_BYTE of the current buffer to
 491    the previous character boundary.  No range checking of POS.  */
 492
 493 #define DEC_POS(pos_byte)                       \
 494   do {                                          \
 495     unsigned char *p;                           \
 496                                                 \
 497     pos_byte--;                                 \
 498     if (pos_byte < GPT_BYTE)                    \
 499       p = BEG_ADDR + pos_byte - BEG_BYTE;       \
 500     else                                        \
 501       p = BEG_ADDR + GAP_SIZE + pos_byte - BEG_BYTE;\
 502     while (!CHAR_HEAD_P (*p))                   \
 503       {                                         \
 504         p--;                                    \
 505         pos_byte--;                             \
 506       }                                         \
 507   } while (0)
 508
 509 /* Increment both CHARPOS and BYTEPOS, each in the appropriate way.  */
 510
 511 #define INC_BOTH(charpos, bytepos)                              \
 512   do                                                            \
 513     {                                                           \
 514       (charpos)++;                                              \
 515       if (NILP (current_buffer->enable_multibyte_characters))   \
 516         (bytepos)++;                                            \
 517       else                                                      \
 518         INC_POS ((bytepos));                                    \
 519     }                                                           \
 520   while (0)
 521
 522
 523 /* Decrement both CHARPOS and BYTEPOS, each in the appropriate way.  */
 524
 525 #define DEC_BOTH(charpos, bytepos)                              \
 526   do                                                            \
 527     {                                                           \
 528       (charpos)--;                                              \
 529       if (NILP (current_buffer->enable_multibyte_characters))   \
 530         (bytepos)--;                                            \
 531       else                                                      \
 532         DEC_POS ((bytepos));                                    \
 533     }                                                           \
 534   while (0)
 535
 536
 537 /* Increment the buffer byte position POS_BYTE of the current buffer to
 538    the next character boundary.  This macro relies on the fact that
 539    *GPT_ADDR and *Z_ADDR are always accessible and the values are
 540    '\0'.  No range checking of POS_BYTE.  */
 541
 542 #define BUF_INC_POS(buf, pos_byte)                              \
 543   do {                                                          \
 544     unsigned char *p = BUF_BYTE_ADDRESS (buf, pos_byte);        \
 545     pos_byte += BYTES_BY_CHAR_HEAD (*p);                        \
 546   } while (0)
 547
 548
 549 /* Decrement the buffer byte position POS_BYTE of the current buffer to
 550    the previous character boundary.  No range checking of POS_BYTE.  */
 551
 552 #define BUF_DEC_POS(buf, pos_byte)                                      \
 553   do {                                                                  \
 554     unsigned char *p;                                                   \
 555     pos_byte--;                                                         \
 556     if (pos_byte < BUF_GPT_BYTE (buf))                                  \
 557       p = BUF_BEG_ADDR (buf) + pos_byte - BEG_BYTE;                     \
 558     else                                                                \
 559       p = BUF_BEG_ADDR (buf) + BUF_GAP_SIZE (buf) + pos_byte - BEG_BYTE;\
 560     while (!CHAR_HEAD_P (*p))                                           \
 561       {                                                                 \
 562         p--;                                                            \
 563         pos_byte--;                                                     \
 564       }                                                                 \
 565   } while (0)
 566
 567
 568 /* If C is a character to be unified with a Unicode character, return
 569    the unified Unicode character.  */
 570
 571 #define MAYBE_UNIFY_CHAR(c)                             \
 572   do {                                                  \
 573     if (c > MAX_UNICODE_CHAR && c <= MAX_5_BYTE_CHAR)   \
 574       {                                                 \
 575         Lisp_Object val;                                \
 576         val = CHAR_TABLE_REF (Vchar_unify_table, c);    \
 577         if (INTEGERP (val))                             \
 578           c = XINT (val);                               \
 579         else if (! NILP (val))                          \
 580           c = maybe_unify_char (c, val);                \
 581       }                                                 \
 582   } while (0)
 583
 584
 585 /* Return the width of ASCII character C.  The width is measured by
 586    how many columns C will occupy on the screen when displayed in the
 587    current buffer.  */
 588
 589 #define ASCII_CHAR_WIDTH(c)                                             \
 590   (c < 0x20                                                             \
 591    ? (c == '\t'                                                         \
 592       ? XFASTINT (current_buffer->tab_width)                            \
 593       : (c == '\n' ? 0 : (NILP (current_buffer->ctl_arrow) ? 4 : 2)))   \
 594    : (c < 0x7f                                                          \
 595       ? 1                                                               \
 596       : ((NILP (current_buffer->ctl_arrow) ? 4 : 2))))
 597
 598 /* Return the width of character C.  The width is measured by how many
 599    columns C will occupy on the screen when displayed in the current
 600    buffer.  */
 601
 602 #define CHAR_WIDTH(c)           \
 603   (ASCII_CHAR_P (c)             \
 604    ? ASCII_CHAR_WIDTH (c)       \
 605    : XINT (CHAR_TABLE_REF (Vchar_width_table, c)))
 606
 607 /* If C is a variation selector, return the index numnber of the
 608    variation selector (1..256).  Otherwise, return 0.  */
 609
 610 #define CHAR_VARIATION_SELECTOR_P(c)            \
 611   ((c) < 0xFE00 ? 0                             \
 612    : (c) <= 0xFE0F ? (c) - 0xFE00 + 1           \
 613    : (c) < 0xE0100 ? 0                          \
 614    : (c) <= 0xE01EF ? (c) - 0xE0100 + 17        \
 615    : 0)
 616
 617 /* If C is a high surrogate, return 1.  If C is a low surrogate,
 618    return 0. Otherwise, return 0.  */
 619
 620 #define CHAR_SURROGATE_PAIR_P(c)        \
 621   ((c) < 0xD800 ? 0                     \
 622    : (c) <= 0xDBFF ? 1                  \
 623    : (c) <= 0xDFFF ? 2                  \
 624    : 0)
 625
 626
 627 extern int char_resolve_modifier_mask P_ ((int));
 628 extern int char_string P_ ((unsigned, unsigned char *));
 629 extern int string_char P_ ((const unsigned char *,
 630                             const unsigned char **, int *));
 631
 632 extern int translate_char P_ ((Lisp_Object, int c));
 633 extern int char_printable_p P_ ((int c));
 634 extern void parse_str_as_multibyte P_ ((const unsigned char *, int, int *,
 635                                         int *));
 636 extern int parse_str_to_multibyte P_ ((unsigned char *, int));
 637 extern int str_as_multibyte P_ ((unsigned char *, int, int, int *));
 638 extern int str_to_multibyte P_ ((unsigned char *, int, int));
 639 extern int str_as_unibyte P_ ((unsigned char *, int));
 640 extern EMACS_INT str_to_unibyte P_ ((const unsigned char *, unsigned char *,
 641                                      EMACS_INT, int));
 642 extern int strwidth P_ ((unsigned char *, int));
 643 extern int c_string_width P_ ((const unsigned char *, int, int, int *, int *));
 644 extern int lisp_string_width P_ ((Lisp_Object, int, int *, int *));
 645
 646 extern Lisp_Object Vprintable_chars;
 647
 648 extern Lisp_Object Qcharacterp, Qauto_fill_chars;
 649 extern Lisp_Object Vtranslation_table_vector;
 650 extern Lisp_Object Vchar_width_table;
 651 extern Lisp_Object Vchar_direction_table;
 652 extern Lisp_Object Vchar_unify_table;
 653 extern Lisp_Object Vunicode_category_table;
 654
 655 extern Lisp_Object string_escape_byte8 P_ ((Lisp_Object));
 656
 657 /* Return a translation table of id number ID.  */
 658 #define GET_TRANSLATION_TABLE(id) \
 659   (XCDR(XVECTOR(Vtranslation_table_vector)->contents[(id)]))
 660
 661 /* A char-table for characters which may invoke auto-filling.  */
 662 extern Lisp_Object Vauto_fill_chars;
 663
 664 extern Lisp_Object Vchar_script_table;
 665 extern Lisp_Object Vscript_representative_chars;
 666
 667 /* Copy LEN bytes from FROM to TO.  This macro should be used only
 668    when a caller knows that LEN is short and the obvious copy loop is
 669    faster than calling bcopy which has some overhead.  Copying a
 670    multibyte sequence of a character is the typical case.  */
 671
 672 #define BCOPY_SHORT(from, to, len)              \
 673   do {                                          \
 674     int i = len;                                \
 675     unsigned char *from_p = from, *to_p = to;   \
 676     while (i--) *to_p++ = *from_p++;            \
 677   } while (0)
 678
 679 #define DEFSYM(sym, name)       \
 680   do { (sym) = intern ((name)); staticpro (&(sym)); } while (0)
 681
 682 #endif /* EMACS_CHARACTER_H */
 683
 684 /* arch-tag: 4ef86004-2eff-4073-8cea-cfcbcf7188ac
 685    (do not change this comment) */