rand: update module

pull/4214/head
Alexey 2020-04-03 09:53:57 +03:00 committed by GitHub
parent 5e6aa5371a
commit ef339a4896
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2 changed files with 52 additions and 61 deletions

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@ -1,8 +1,13 @@
// 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
fn C.rand() int
fn C.srand(u32)
pub fn seed(s int) {
C.srand(s)
}
@ -11,24 +16,10 @@ 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
// rand_r returns a pseudo-random number;
// writes a result value to the seed argument.
pub fn rand_r(seed mut int) int {
ns := *seed * 1103515245 + 12345
(*seed) = ns
return ns & 0x7fffffff
}
}

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@ -1,58 +1,58 @@
import rand
const (
rnd_count = 20
seeds = [42, 256]
)
fn test_rand_reproducibility() {
for seed in seeds {
mut randoms1 := gen_randoms(seed)
mut randoms2 := gen_randoms(seed)
assert_randoms_equal(randoms1, randoms2)
}
}
fn test_rand_r_reproducibility() {
for seed in seeds {
mut randoms1 := gen_randoms_r(seed)
mut randoms2 := gen_randoms_r(seed)
assert_randoms_equal(randoms1, randoms2)
}
}
fn test_rand_r_seed_update() {
seed := 10
for _ in 0..rnd_count {
prev_seed := seed
res := rand.rand_r(&seed)
assert prev_seed != seed
}
}
fn gen_randoms(seed int) []int {
mut randoms := [0].repeat(20)
mut randoms := [0].repeat(rnd_count)
rand.seed(seed)
for i in 0..20 {
for i in 0..rnd_count {
randoms[i] = rand.next(100)
}
return randoms
}
fn test_rand_reproducibility() {
mut randoms1 := gen_randoms(42)
mut randoms2 := gen_randoms(42)
assert randoms1.len == randoms2.len
mut len := randoms1.len
for i in 0..len {
assert randoms1[i] == randoms2[i]
}
randoms1 = gen_randoms(256)
randoms2 = gen_randoms(256)
assert randoms1.len == randoms2.len
len = randoms1.len
for i in 0..len {
assert randoms1[i] == randoms2[i]
}
}
fn gen_randoms_r(seed int) []int {
mut randoms := [0].repeat(20)
for i in 0..20 {
mut randoms := [0].repeat(rnd_count)
for i in 0..rnd_count {
randoms[i] = rand.rand_r(&seed)
}
return randoms
}
fn test_rand_r_reproducibility() {
mut randoms1 := gen_randoms_r(42)
mut randoms2 := gen_randoms_r(42)
assert randoms1.len == randoms2.len
mut len := randoms1.len
for i in 0..len {
assert randoms1[i] == randoms2[i]
}
randoms1 = gen_randoms_r(256)
randoms2 = gen_randoms_r(256)
assert randoms1.len == randoms2.len
len = randoms1.len
for i in 0..len {
assert randoms1[i] == randoms2[i]
fn assert_randoms_equal(r1, r2 []int) {
for i in 0..rnd_count {
assert r1[i] == r2[i]
}
}