root/maint/gnulib/lib/unicase/u-suffix-context.h

/* */

INCLUDED FROM

DEFINITIONS

1. FUNC1
2. FUNC2

   1 /* Case-mapping context of suffix UTF-8/UTF-16/UTF-32 string.
   2    Copyright (C) 2009-2021 Free Software Foundation, Inc.
   3    Written by Bruno Haible <bruno@clisp.org>, 2009.
   4 
   5    This file is free software.
   6    It is dual-licensed under "the GNU LGPLv3+ or the GNU GPLv2+".
   7    You can redistribute it and/or modify it under either
   8      - the terms of the GNU Lesser General Public License as published
   9        by the Free Software Foundation; either version 3, or (at your
  10        option) any later version, or
  11      - the terms of the GNU General Public License as published by the
  12        Free Software Foundation; either version 2, or (at your option)
  13        any later version, or
  14      - the same dual license "the GNU LGPLv3+ or the GNU GPLv2+".
  15 
  16    This file is distributed in the hope that it will be useful,
  17    but WITHOUT ANY WARRANTY; without even the implied warranty of
  18    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19    Lesser General Public License and the GNU General Public License
  20    for more details.
  21 
  22    You should have received a copy of the GNU Lesser General Public
  23    License and of the GNU General Public License along with this
  24    program.  If not, see <https://www.gnu.org/licenses/>.  */
  25 
  26 casing_suffix_context_t
  27 FUNC1 (const UNIT *s, size_t n)
     /*  */
  28 {
  29   return FUNC2 (s, n, unicase_empty_suffix_context);
  30 }
  31 
  32 casing_suffix_context_t
  33 FUNC2 (const UNIT *s, size_t n, casing_suffix_context_t a_context)
     /*  */
  34 {
  35   casing_suffix_context_t context;
  36   /* Evaluate all three conditions in a single pass through the string S.
  37      The three variables are -1 as long as the value of the condition has
  38      not been determined.  */
  39   ucs4_t first_char_except_ignorable = (ucs4_t)(-1);
  40   int scc_MORE_ABOVE = -1;
  41   int scc_BEFORE_DOT = -1;
  42   const UNIT *s_end = s + n;
  43 
  44   while (s < s_end)
  45     {
  46       ucs4_t uc;
  47       int count = U_MBTOUC_UNSAFE (&uc, s, s_end - s);
  48 
  49       if (first_char_except_ignorable == (ucs4_t)(-1))
  50         {
  51           if (!uc_is_case_ignorable (uc))
  52             first_char_except_ignorable = uc;
  53         }
  54 
  55       if (scc_MORE_ABOVE < 0)
  56         {
  57           int ccc = uc_combining_class (uc);
  58           if (ccc == UC_CCC_A)
  59             scc_MORE_ABOVE = SCC_MORE_ABOVE_MASK;
  60           else if (ccc == UC_CCC_NR)
  61             scc_MORE_ABOVE = 0;
  62         }
  63 
  64       if (scc_BEFORE_DOT < 0)
  65         {
  66           if (uc == 0x0307) /* COMBINING DOT ABOVE */
  67             scc_BEFORE_DOT = SCC_BEFORE_DOT_MASK;
  68           else
  69             {
  70               int ccc = uc_combining_class (uc);
  71               if (ccc == UC_CCC_A || ccc == UC_CCC_NR)
  72                 scc_BEFORE_DOT = 0;
  73             }
  74         }
  75 
  76       if (first_char_except_ignorable != (ucs4_t)(-1)
  77           && (scc_MORE_ABOVE | scc_BEFORE_DOT) >= 0)
  78         /* All conditions have been determined.  */
  79         break;
  80 
  81       s += count;
  82     }
  83 
  84   /* For those conditions that have not been determined so far, use the
  85      value from the argument context.  */
  86   context.first_char_except_ignorable =
  87     (first_char_except_ignorable != (ucs4_t)(-1)
  88      ? first_char_except_ignorable
  89      : a_context.first_char_except_ignorable);
  90   context.bits =
  91     (scc_MORE_ABOVE >= 0
  92      ? scc_MORE_ABOVE
  93      : a_context.bits & SCC_MORE_ABOVE_MASK)
  94     | (scc_BEFORE_DOT >= 0
  95        ? scc_BEFORE_DOT
  96        : a_context.bits & SCC_BEFORE_DOT_MASK);
  97   return context;
  98 }

/* */