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Annotation of embedaddon/libiconv/lib/johab.h, revision 1.1.1.1

1.1       misho       1: /*
                      2:  * Copyright (C) 1999-2001, 2007 Free Software Foundation, Inc.
                      3:  * This file is part of the GNU LIBICONV Library.
                      4:  *
                      5:  * The GNU LIBICONV Library is free software; you can redistribute it
                      6:  * and/or modify it under the terms of the GNU Library General Public
                      7:  * License as published by the Free Software Foundation; either version 2
                      8:  * of the License, or (at your option) any later version.
                      9:  *
                     10:  * The GNU LIBICONV Library is distributed in the hope that it will be
                     11:  * useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
                     12:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
                     13:  * Library General Public License for more details.
                     14:  *
                     15:  * You should have received a copy of the GNU Library General Public
                     16:  * License along with the GNU LIBICONV Library; see the file COPYING.LIB.
                     17:  * If not, write to the Free Software Foundation, Inc., 51 Franklin Street,
                     18:  * Fifth Floor, Boston, MA 02110-1301, USA.
                     19:  */
                     20: 
                     21: /*
                     22:  * JOHAB
                     23:  */
                     24: 
                     25: /*
                     26:    Conversion between JOHAB codes (s1,s2) and KSX1001 codes (c1,c2):
                     27:    Example. (s1,s2) = 0xD931, (c1,c2) = 0x2121.
                     28:             (s1,s2) = 0xDEF1, (c1,c2) = 0x2C71.
                     29:             (s1,s2) = 0xE031, (c1,c2) = 0x4A21.
                     30:             (s1,s2) = 0xF9FE, (c1,c2) = 0x7D7E.
                     31:    0xD9 <= s1 <= 0xDE || 0xE0 <= s1 <= 0xF9,
                     32:    0x31 <= s2 <= 0x7E || 0x91 <= s2 <= 0xFE,
                     33:    0x21 <= c1 <= 0x2C || 0x4A <= c1 <= 0x7D,
                     34:    0x21 <= c2 <= 0x7E.
                     35:    Invariant:
                     36:      94*(s1 < 0xE0 ? 2*s1-0x1B2 : 2*s1-0x197) + (s2 < 0x91 ? s2-0x31 : s2-0x43)
                     37:      = 94*(c1-0x21)+(c2-0x21)
                     38:    Conversion (s1,s2) -> (c1,c2):
                     39:      t1 := (s1 < 0xE0 ? 2*s1-0x1B2 : 2*s1-0x197)
                     40:      t2 := (s2 < 0x91 ? s2-0x31 : s2-0x43)
                     41:      c1 := t1 + (t2 < 0x5E ? 0 : 1) + 0x21
                     42:      c2 := (t2 < 0x5E ? t2 : t2-0x5E) + 0x21
                     43:    Conversion (c1,c2) -> (s1,s2):
                     44:      t := (c1 < 0x4A ? (c1-0x21+0x1B2) : (c1-0x21+0x197))
                     45:      s1 := t >> 1
                     46:      t2 := (t & 1) * 0x5E + (c2 - 0x21)
                     47:      s2 := (t2 < 0x4E ? t2+0x31 : t2+0x43)
                     48:  */
                     49: 
                     50: static int
                     51: johab_mbtowc (conv_t conv, ucs4_t *pwc, const unsigned char *s, int n)
                     52: {
                     53:   unsigned char c = *s;
                     54:   if (c < 0x80) {
                     55:     if (c == 0x5c)
                     56:       *pwc = (ucs4_t) 0x20a9;
                     57:     else
                     58:       *pwc = (ucs4_t) c;
                     59:     return 1;
                     60:   } else if (c < 0xd8) {
                     61:     return johab_hangul_mbtowc(conv,pwc,s,n);
                     62:   } else {
                     63:     unsigned char s1, s2;
                     64:     s1 = c;
                     65:     if ((s1 >= 0xd9 && s1 <= 0xde) || (s1 >= 0xe0 && s1 <= 0xf9)) {
                     66:       if (n < 2)
                     67:         return RET_TOOFEW(0);
                     68:       s2 = s[1];
                     69:       if ((s2 >= 0x31 && s2 <= 0x7e) || (s2 >= 0x91 && s2 <= 0xfe)) {
                     70:         /* In KSC 5601, now KS X 1001, the region s1 = 0xDA, 0xA1 <= s2 <= 0xD3
                     71:            contains the 51 Jamo (Hangul letters). But in the Johab encoding,
                     72:            they have been moved to the Hangul section, see
                     73:            johab_hangul_page31. */
                     74:         if (!(s1 == 0xda && (s2 >= 0xa1 && s2 <= 0xd3))) {
                     75:           unsigned char t1 = (s1 < 0xe0 ? 2*(s1-0xd9) : 2*s1-0x197);
                     76:           unsigned char t2 = (s2 < 0x91 ? s2-0x31 : s2-0x43);
                     77:           unsigned char buf[2];
                     78:           buf[0] = t1 + (t2 < 0x5e ? 0 : 1) + 0x21;
                     79:           buf[1] = (t2 < 0x5e ? t2 : t2-0x5e) + 0x21;
                     80:           return ksc5601_mbtowc(conv,pwc,buf,2);
                     81:         }
                     82:       }
                     83:     }
                     84:     return RET_ILSEQ;
                     85:   }
                     86: }
                     87: 
                     88: static int
                     89: johab_wctomb (conv_t conv, unsigned char *r, ucs4_t wc, int n)
                     90: {
                     91:   unsigned char buf[2];
                     92:   int ret;
                     93: 
                     94:   /* Try ASCII variation. */
                     95:   if (wc < 0x0080 && wc != 0x005c) {
                     96:     *r = wc;
                     97:     return 1;
                     98:   }
                     99:   if (wc == 0x20a9) {
                    100:     *r = 0x5c;
                    101:     return 1;
                    102:   }
                    103: 
                    104:   /* Try JOHAB Hangul table before KSC5601 table, because the KSC5601 table
                    105:      contains some (2350 out of 11172) Hangul syllables (rows 0x30XX..0x48XX),
                    106:      and we want the search to return the JOHAB Hangul table entry. */
                    107: 
                    108:   /* Try JOHAB Hangul. */
                    109:   ret = johab_hangul_wctomb(conv,buf,wc,2);
                    110:   if (ret != RET_ILUNI) {
                    111:     if (ret != 2) abort();
                    112:     if (n < 2)
                    113:       return RET_TOOSMALL;
                    114:     r[0] = buf[0];
                    115:     r[1] = buf[1];
                    116:     return 2;
                    117:   }
                    118: 
                    119:   /* Try KSC5601, now KS X 1001. */
                    120:   ret = ksc5601_wctomb(conv,buf,wc,2);
                    121:   if (ret != RET_ILUNI) {
                    122:     unsigned char c1, c2;
                    123:     if (ret != 2) abort();
                    124:     if (n < 2)
                    125:       return RET_TOOSMALL;
                    126:     c1 = buf[0];
                    127:     c2 = buf[1];
                    128:     if (((c1 >= 0x21 && c1 <= 0x2c) || (c1 >= 0x4a && c1 <= 0x7d))
                    129:         && (c2 >= 0x21 && c2 <= 0x7e)) {
                    130:       unsigned int t = (c1 < 0x4A ? (c1-0x21+0x1B2) : (c1-0x21+0x197));
                    131:       unsigned char t2 = ((t & 1) ? 0x5e : 0) + (c2 - 0x21);
                    132:       r[0] = t >> 1;
                    133:       r[1] = (t2 < 0x4e ? t2+0x31 : t2+0x43);
                    134:       return 2;
                    135:     }
                    136:   }
                    137: 
                    138:   return RET_ILUNI;
                    139: }