iso2022_jp3.h

libiconv是一个很不错的字符集转换库。程序接口也很简单

/*
 * Copyright (C) 1999-2002 Free Software Foundation, Inc.
 * This file is part of the GNU LIBICONV Library.
 *
 * The GNU LIBICONV Library is free software; you can redistribute it
 * and/or modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * The GNU LIBICONV Library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with the GNU LIBICONV Library; see the file COPYING.LIB.
 * If not, write to the Free Software Foundation, Inc., 59 Temple Place -
 * Suite 330, Boston, MA 02111-1307, USA.
 */

/*
 * ISO-2022-JP-3
 */

#include "jisx0213.h"

#define ESC 0x1b

/*
 * The state is composed of one of the following values
 */
#define STATE_ASCII             0  /* Esc ( B */
#define STATE_JISX0201ROMAN     1  /* Esc ( J */
#define STATE_JISX0201KATAKANA  2  /* Esc ( I */
#define STATE_JISX0208          3  /* Esc $ @ or Esc $ B */
#define STATE_JISX02131         4  /* Esc $ ( O */
#define STATE_JISX02132         5  /* Esc $ ( P */

/*
 * In the ISO-2022-JP-3 to UCS-4 direction, the state also holds the last
 * character to be output, shifted by 3 bits.
 */

static int
iso2022_jp3_mbtowc (conv_t conv, ucs4_t *pwc, const unsigned char *s, int n)
{
  ucs4_t last_wc = conv->istate >> 3;
  if (last_wc) {
    /* Output the buffered character. */
    conv->istate &= 7;
    *pwc = last_wc;
    return 0; /* Don't advance the input pointer. */
  } else {
    state_t state = conv->istate;
    int count = 0;
    unsigned char c;
    for (;;) {
      c = *s;
      if (c == ESC) {
        if (n < count+3)
          goto none;
        if (s[1] == '(') {
          if (s[2] == 'B') {
            state = STATE_ASCII;
            s += 3; count += 3;
            if (n < count+1)
              goto none;
            continue;
          }
          if (s[2] == 'J') {
            state = STATE_JISX0201ROMAN;
            s += 3; count += 3;
            if (n < count+1)
              goto none;
            continue;
          }
          if (s[2] == 'I') {
            state = STATE_JISX0201KATAKANA;
            s += 3; count += 3;
            if (n < count+1)
              goto none;
            continue;
          }
          return RET_ILSEQ;
        }
        if (s[1] == '$') {
          if (s[2] == '@' || s[2] == 'B') {
            /* We don't distinguish JIS X 0208-1978 and JIS X 0208-1983. */
            state = STATE_JISX0208;
            s += 3; count += 3;
            if (n < count+1)
              goto none;
            continue;
          }
          if (s[2] == '(') {
            if (n < count+4)
              goto none;
            if (s[3] == 'O') {
              state = STATE_JISX02131;
              s += 4; count += 4;
              if (n < count+1)
                goto none;
              continue;
            }
            if (s[3] == 'P') {
              state = STATE_JISX02132;
              s += 4; count += 4;
              if (n < count+1)
                goto none;
              continue;
            }
          }
          return RET_ILSEQ;
        }
        return RET_ILSEQ;
      }
      break;
    }
    switch (state) {
      case STATE_ASCII:
        if (c < 0x80) {
          int ret = ascii_mbtowc(conv,pwc,s,1);
          if (ret == RET_ILSEQ)
            return RET_ILSEQ;
          if (ret != 1) abort();
          conv->istate = state;
          return count+1;
        } else
          return RET_ILSEQ;
      case STATE_JISX0201ROMAN:
        if (c < 0x80) {
          int ret = jisx0201_mbtowc(conv,pwc,s,1);
          if (ret == RET_ILSEQ)
            return RET_ILSEQ;
          if (ret != 1) abort();
          conv->istate = state;
          return count+1;
        } else
          return RET_ILSEQ;
      case STATE_JISX0201KATAKANA:
        if (c < 0x80) {
          unsigned char buf = c+0x80;
          int ret = jisx0201_mbtowc(conv,pwc,&buf,1);
          if (ret == RET_ILSEQ)
            return RET_ILSEQ;
          if (ret != 1) abort();
          conv->istate = state;
          return count+1;
        } else
          return RET_ILSEQ;
      case STATE_JISX0208:
        if (n < count+2)
          goto none;
        if (s[0] < 0x80 && s[1] < 0x80) {
          int ret = jisx0208_mbtowc(conv,pwc,s,2);
          if (ret == RET_ILSEQ)
            return RET_ILSEQ;
          if (ret != 2) abort();
          conv->istate = state;
          return count+2;
        } else
          return RET_ILSEQ;
      case STATE_JISX02131:
      case STATE_JISX02132:
        if (n < count+2)
          goto none;
        if (s[0] < 0x80 && s[1] < 0x80) {
          ucs4_t wc = jisx0213_to_ucs4(((state-STATE_JISX02131+1)<<8)+s[0],s[1]);
          if (wc) {
            if (wc < 0x80) {
              /* It's a combining character. */
              ucs4_t wc1 = jisx0213_to_ucs_combining[wc - 1][0];
              ucs4_t wc2 = jisx0213_to_ucs_combining[wc - 1][1];
              /* We cannot output two Unicode characters at once. So,
                 output the first character and buffer the second one. */
              *pwc = wc1;
              conv->istate = (wc2 << 3) | state;
            } else {
              *pwc = wc;
              conv->istate = state;
            }
            return count+2;
          }
        }
        return RET_ILSEQ;
      default: abort();
    }
  none:
    conv->istate = state;
    return RET_TOOFEW(count);
  }
}

static int
iso2022_jp3_flushwc (conv_t conv, ucs4_t *pwc)
{
  ucs4_t last_wc = conv->istate >> 3;
  if (last_wc) {
    /* Output the buffered character. */
    conv->istate &= 7;
    *pwc = last_wc;
    return 1;
  } else
    return 0;
}

/*
 * In the UCS-4 to ISO-2022-JP-3 direction, the state also holds the last two
 * bytes to be output, shifted by 3 bits, and the STATE_xxxxx value that was
 * effective before this buffered character, shifted by 19 bits.
 */

/* Composition tables for each of the relevant combining characters.  */
static const struct { unsigned short base; unsigned short composed; } iso2022_jp3_comp_table_data[] = {
#define iso2022_jp3_comp_table02e5_idx 0
#define iso2022_jp3_comp_table02e5_len 1
  { 0x2b64, 0x2b65 }, /* 0x12B65 = 0x12B64 U+02E5 */
#define iso2022_jp3_comp_table02e9_idx (iso2022_jp3_comp_table02e5_idx+iso2022_jp3_comp_table02e5_len)
#define iso2022_jp3_comp_table02e9_len 1
  { 0x2b60, 0x2b66 }, /* 0x12B66 = 0x12B60 U+02E9 */
#define iso2022_jp3_comp_table0300_idx (iso2022_jp3_comp_table02e9_idx+iso2022_jp3_comp_table02e9_len)
#define iso2022_jp3_comp_table0300_len 5
  { 0x295c, 0x2b44 }, /* 0x12B44 = 0x1295C U+0300 */
  { 0x2b38, 0x2b48 }, /* 0x12B48 = 0x12B38 U+0300 */
  { 0x2b37, 0x2b4a }, /* 0x12B4A = 0x12B37 U+0300 */
  { 0x2b30, 0x2b4c }, /* 0x12B4C = 0x12B30 U+0300 */
  { 0x2b43, 0x2b4e }, /* 0x12B4E = 0x12B43 U+0300 */
#define iso2022_jp3_comp_table0301_idx (iso2022_jp3_comp_table0300_idx+iso2022_jp3_comp_table0300_len)
#define iso2022_jp3_comp_table0301_len 4
  { 0x2b38, 0x2b49 }, /* 0x12B49 = 0x12B38 U+0301 */
  { 0x2b37, 0x2b4b }, /* 0x12B4B = 0x12B37 U+0301 */
  { 0x2b30, 0x2b4d }, /* 0x12B4D = 0x12B30 U+0301 */
  { 0x2b43, 0x2b4f }, /* 0x12B4F = 0x12B43 U+0301 */
#define iso2022_jp3_comp_table309a_idx (iso2022_jp3_comp_table0301_idx+iso2022_jp3_comp_table0301_len)
#define iso2022_jp3_comp_table309a_len 14
  { 0x242b, 0x2477 }, /* 0x12477 = 0x1242B U+309A */
  { 0x242d, 0x2478 }, /* 0x12478 = 0x1242D U+309A */
  { 0x242f, 0x2479 }, /* 0x12479 = 0x1242F U+309A */
  { 0x2431, 0x247a }, /* 0x1247A = 0x12431 U+309A */
  { 0x2433, 0x247b }, /* 0x1247B = 0x12433 U+309A */
  { 0x252b, 0x2577 }, /* 0x12577 = 0x1252B U+309A */
  { 0x252d, 0x2578 }, /* 0x12578 = 0x1252D U+309A */
  { 0x252f, 0x2579 }, /* 0x12579 = 0x1252F U+309A */
  { 0x2531, 0x257a }, /* 0x1257A = 0x12531 U+309A */
  { 0x2533, 0x257b }, /* 0x1257B = 0x12533 U+309A */
  { 0x253b, 0x257c }, /* 0x1257C = 0x1253B U+309A */
  { 0x2544, 0x257d }, /* 0x1257D = 0x12544 U+309A */
  { 0x2548, 0x257e }, /* 0x1257E = 0x12548 U+309A */
  { 0x2675, 0x2678 }, /* 0x12678 = 0x12675 U+309A */
};

#define SPLIT_STATE \
  unsigned short lasttwo = state >> 3; state_t prevstate = state >> 19; state &= 7
#define COMBINE_STATE \
  state |= (prevstate << 19) | (lasttwo << 3)
#define COMBINE_STATE_NO_LASTTWO \
  /* assume lasttwo == 0, then prevstate is ignored */

static int
iso2022_jp3_wctomb (conv_t conv, unsigned char *r, ucs4_t wc, int n)
{
  int count = 0;
  unsigned char buf[2];
  unsigned short jch;
  int ret;
  state_t state = conv->ostate;
  SPLIT_STATE;