1 /* Generate random integers.
2
3 Copyright (C) 2006-2023 Free Software Foundation, Inc.
4
5 This program is free software: you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 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
13 GNU General Public License for more details.
14
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <https://www.gnu.org/licenses/>. */
17
18 /* Written by Paul Eggert. */
19
20 #ifndef RANDINT_H
21
22 # define RANDINT_H 1
23
24 # include <stdint.h>
25
26 # include "randread.h"
27
28 /* An unsigned integer type, used for random integers, and its maximum
29 value. */
30 typedef uintmax_t randint;
31 # define RANDINT_MAX UINTMAX_MAX
32
33 struct randint_source;
34
35 void randint_free (struct randint_source *) _GL_ATTRIBUTE_NONNULL ();
36 int randint_all_free (struct randint_source *) _GL_ATTRIBUTE_NONNULL ();
37 struct randint_source *randint_new (struct randread_source *)
38 _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_DEALLOC (randint_free, 1)
39 _GL_ATTRIBUTE_NONNULL () _GL_ATTRIBUTE_RETURNS_NONNULL;
40 struct randint_source *randint_all_new (char const *, size_t)
41 _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_DEALLOC (randint_all_free, 1);
42 struct randread_source *randint_get_source (struct randint_source const *)
43 _GL_ATTRIBUTE_NONNULL () _GL_ATTRIBUTE_PURE;
44 randint randint_genmax (struct randint_source *, randint genmax)
45 _GL_ATTRIBUTE_NONNULL ();
46
47 /* Consume random data from *S to generate a random number in the range
48 0 .. CHOICES-1. CHOICES must be nonzero. */
49 static inline randint
randint_choose(struct randint_source * s,randint choices)50 randint_choose (struct randint_source *s, randint choices)
51 {
52 return randint_genmax (s, choices - 1);
53 }
54
55 #endif
56