kc3-lang/gnulib/lib/uninorm/decomposition.c

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• Hash : 32a72f45
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  Date : 2023-01-01T01:14:21
  

  maint: run 'make update-copyright'
  

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• lib/uninorm/decomposition.c

• /* Decomposition of Unicode characters.
     Copyright (C) 2009-2023 Free Software Foundation, Inc.
     Written by Bruno Haible <bruno@clisp.org>, 2009.
  
     This file is free software.
     It is dual-licensed under "the GNU LGPLv3+ or the GNU GPLv2+".
     You can redistribute it and/or modify it under either
       - the terms of the GNU Lesser General Public License as published
         by the Free Software Foundation, either version 3, or (at your
         option) any later version, or
       - the terms of the GNU General Public License as published by the
         Free Software Foundation; either version 2, or (at your option)
         any later version, or
       - the same dual license "the GNU LGPLv3+ or the GNU GPLv2+".
  
     This file 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
     Lesser General Public License and the GNU General Public License
     for more details.
  
     You should have received a copy of the GNU Lesser General Public
     License and of the GNU General Public License along with this
     program.  If not, see <https://www.gnu.org/licenses/>.  */
  
  #include <config.h>
  
  /* Specification.  */
  #include "uninorm.h"
  
  #include "uninorm/decomposition-table.h"
  
  int
  uc_decomposition (ucs4_t uc, int *decomp_tag, ucs4_t *decomposition)
  {
    if (uc >= 0xAC00 && uc < 0xD7A4)
      {
        /* Hangul syllable.  See Unicode standard, chapter 3, section
           "Hangul Syllable Decomposition",  See also the clarification at
           <https://www.unicode.org/versions/Unicode5.1.0/>, section
           "Clarification of Hangul Jamo Handling".  */
        unsigned int t;
  
        uc -= 0xAC00;
        t = uc % 28;
  
        *decomp_tag = UC_DECOMP_CANONICAL;
        if (t == 0)
          {
            unsigned int v, l;
  
            uc = uc / 28;
            v = uc % 21;
            l = uc / 21;
  
            decomposition[0] = 0x1100 + l;
            decomposition[1] = 0x1161 + v;
            return 2;
          }
        else
          {
  #if 1 /* Return the pairwise decomposition, not the full decomposition.  */
            decomposition[0] = 0xAC00 + uc - t; /* = 0xAC00 + (l * 21 + v) * 28; */
            decomposition[1] = 0x11A7 + t;
            return 2;
  #else
            unsigned int v, l;
  
            uc = uc / 28;
            v = uc % 21;
            l = uc / 21;
  
            decomposition[0] = 0x1100 + l;
            decomposition[1] = 0x1161 + v;
            decomposition[2] = 0x11A7 + t;
            return 3;
  #endif
          }
      }
    else if (uc < 0x110000)
      {
        unsigned short entry = decomp_index (uc);
        if (entry != (unsigned short)(-1))
          {
            const unsigned char *p;
            unsigned int element;
            unsigned int length;
  
            p = &gl_uninorm_decomp_chars_table[3 * (entry & 0x7FFF)];
            element = (p[0] << 16) | (p[1] << 8) | p[2];
            /* The first element has 5 bits for the decomposition type.  */
            *decomp_tag = (element >> 18) & 0x1f;
            length = 1;
            for (;;)
              {
                /* Every element has an 18 bits wide Unicode code point.  */
                *decomposition = element & 0x3ffff;
                /* Bit 23 tells whether there are more elements,  */
                if ((element & (1 << 23)) == 0)
                  break;
                p += 3;
                element = (p[0] << 16) | (p[1] << 8) | p[2];
                decomposition++;
                length++;
              }
            return length;
          }
      }
    return -1;
  }
  

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