gl/lib/randint.h

   1 /* Generate random integers.
   2
   3    Copyright (C) 2006-2024 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
  50 randint_choose (struct randint_source *s, randint choices)
  51 {
  52   return randint_genmax (s, choices - 1);
  53 }
  54
  55 #endif