v/vlib/rand/rand.v

35 lines
608 B
V

// Copyright (c) 2019-2020 Alexander Medvednikov. All rights reserved.
// Use of this source code is governed by an MIT license
// that can be found in the LICENSE file.
module rand
pub fn seed(s int) {
C.srand(s)
}
pub fn next(max int) int {
return C.rand() % max
}
fn C.rand() int
/**
* rand_r - reentrant pseudo-random number generator
*
* @param seed byref reentrant seed, holding current state
*
* @return a value between 0 and C.RAND_MAX (inclusive)
*/
pub fn rand_r(seed &int) int {
unsafe{
mut rs := seed
ns := (*rs * 1103515245 + 12345)
*rs = ns
return ns & 0x7fffffff
}
}