1/* Categories of Unicode characters.
2   Copyright (C) 2002, 2006-2007, 2009-2010 Free Software Foundation, Inc.
3   Written by Bruno Haible <bruno@clisp.org>, 2002.
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 <http://www.gnu.org/licenses/>.  */
17
18#include <config.h>
19
20/* Specification.  */
21#include "unictype.h"
22
23static const char u_category_name[30][3] =
24{
25  "Lu", "Ll", "Lt", "Lm", "Lo", "Mn", "Mc", "Me", "Nd", "Nl",
26  "No", "Pc", "Pd", "Ps", "Pe", "Pi", "Pf", "Po", "Sm", "Sc",
27  "Sk", "So", "Zs", "Zl", "Zp", "Cc", "Cf", "Cs", "Co", "Cn"
28};
29
30const char *
31uc_general_category_name (uc_general_category_t category)
32{
33  uint32_t bitmask = category.bitmask;
34  /* bitmask should consist of a single bit.  */
35  if (bitmask != 0)
36    {
37      if ((bitmask & (bitmask - 1)) == 0)
38        {
39          int bit;
40          /* Take log2 using a variant of Robert Harley's method.
41             Found by Bruno Haible 1996.  */
42          uint32_t n = bitmask;
43          static const char ord2_tab[64] =
44            {
45              -1,  0,  1, 12,  2,  6, -1, 13,  3, -1,  7, -1, -1, -1, -1, 14,
46              10,  4, -1, -1,  8, -1, -1, 25, -1, -1, -1, -1, -1, 21, 27, 15,
47              31, 11,  5, -1, -1, -1, -1, -1,  9, -1, -1, 24, -1, -1, 20, 26,
48              30, -1, -1, -1, -1, 23, -1, 19, 29, -1, 22, 18, 28, 17, 16, -1
49            };
50          n += n << 4;
51          n += n << 6;
52          n = (n << 16) - n;
53          bit = ord2_tab[n >> 26];
54
55          if (bit < sizeof (u_category_name) / sizeof (u_category_name[0]))
56            return u_category_name[bit];
57        }
58      else
59        {
60          if (bitmask == UC_CATEGORY_MASK_L)
61            return "L";
62          if (bitmask == UC_CATEGORY_MASK_M)
63            return "M";
64          if (bitmask == UC_CATEGORY_MASK_N)
65            return "N";
66          if (bitmask == UC_CATEGORY_MASK_P)
67            return "P";
68          if (bitmask == UC_CATEGORY_MASK_S)
69            return "S";
70          if (bitmask == UC_CATEGORY_MASK_Z)
71            return "Z";
72          if (bitmask == UC_CATEGORY_MASK_C)
73            return "C";
74        }
75    }
76  return NULL;
77}
78