lib/unictype/joiningtype_of.c

   1 /* Arabic joining type of Unicode characters.
   2    Copyright (C) 2011-2021 Free Software Foundation, Inc.
   3    Written by Bruno Haible <bruno@clisp.org>, 2011.
   4
   5    This program is free software: you can redistribute it and/or modify it
   6    under the terms of the GNU Lesser General Public License as published
   7    by the Free Software Foundation; either version 3 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public License
  16    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  17
  18 #include <config.h>
  19
  20 /* Specification.  */
  21 #include "unictype.h"
  22
  23 /* Define u_joining_type table.  */
  24 #include "joiningtype_of.h"
  25
  26 int
  27 uc_joining_type (ucs4_t uc)
  28 {
  29   unsigned int index1 = uc >> joining_type_header_0;
  30   if (index1 < joining_type_header_1)
  31     {
  32       int lookup1 = u_joining_type.level1[index1];
  33       if (lookup1 >= 0)
  34         {
  35           unsigned int index2 = (uc >> joining_type_header_2) & joining_type_header_3;
  36           int lookup2 = u_joining_type.level2[lookup1 + index2];
  37           if (lookup2 >= 0)
  38             {
  39               unsigned int index3 = (uc & joining_type_header_4) + lookup2;
  40               /* level3 contains 4-bit values.  */
  41               unsigned int lookup3 =
  42                 (u_joining_type.level3[index3>>1] >> ((index3 % 2) * 4))
  43                 & 0x0f;
  44
  45               if (lookup3 != 0x0f)
  46                 return lookup3;
  47             }
  48         }
  49     }
  50   if (uc_is_general_category_withtable
  51        (uc, UC_CATEGORY_MASK_Mn | UC_CATEGORY_MASK_Me | UC_CATEGORY_MASK_Cf))
  52     return UC_JOINING_TYPE_T;
  53   return UC_JOINING_TYPE_U;
  54 }