mirror of
https://github.com/vlang/v.git
synced 2023-08-10 21:13:21 +03:00
rand: simplify rand.PRNG, move to optional types for error handling (#13570)
This commit is contained in:
Subhomoy Haldar
@ -48,183 +48,6 @@ pub fn (mut rng PCG32RNG) u64() u64 {
|
||||
return u64(rng.u32()) | (u64(rng.u32()) << 32)
|
||||
}
|
||||
|
||||
// u32n returns a pseudorandom 32-bit unsigned `u32` in range `[0, max)`.
|
||||
[inline]
|
||||
pub fn (mut rng PCG32RNG) u32n(max u32) u32 {
|
||||
if max == 0 {
|
||||
eprintln('max must be positive')
|
||||
exit(1)
|
||||
}
|
||||
// To avoid bias, we need to make the range of the RNG a multiple of
|
||||
// max, which we do by dropping output less than a threshold.
|
||||
threshold := (-max % max)
|
||||
// Uniformity guarantees that loop below will terminate. In practice, it
|
||||
// should usually terminate quickly; on average (assuming all max's are
|
||||
// equally likely), 82.25% of the time, we can expect it to require just
|
||||
// one iteration. In practice, max's are typically small and only a
|
||||
// tiny amount of the range is eliminated.
|
||||
for {
|
||||
r := rng.u32()
|
||||
if r >= threshold {
|
||||
return r % max
|
||||
}
|
||||
}
|
||||
return u32(0)
|
||||
}
|
||||
|
||||
// u64n returns a pseudorandom 64-bit unsigned `u64` in range `[0, max)`.
|
||||
[inline]
|
||||
pub fn (mut rng PCG32RNG) u64n(max u64) u64 {
|
||||
if max == 0 {
|
||||
eprintln('max must be positive')
|
||||
exit(1)
|
||||
}
|
||||
threshold := (-max % max)
|
||||
for {
|
||||
r := rng.u64()
|
||||
if r >= threshold {
|
||||
return r % max
|
||||
}
|
||||
}
|
||||
return u64(0)
|
||||
}
|
||||
|
||||
// u32_in_range returns a pseudorandom 32-bit unsigned `u32` in range `[min, max)`.
|
||||
[inline]
|
||||
pub fn (mut rng PCG32RNG) u32_in_range(min u32, max u32) u32 {
|
||||
if max <= min {
|
||||
eprintln('max must be greater than min')
|
||||
exit(1)
|
||||
}
|
||||
return min + rng.u32n(u32(max - min))
|
||||
}
|
||||
|
||||
// u64_in_range returns a pseudorandom 64-bit unsigned `u64` in range `[min, max)`.
|
||||
[inline]
|
||||
pub fn (mut rng PCG32RNG) u64_in_range(min u64, max u64) u64 {
|
||||
if max <= min {
|
||||
eprintln('max must be greater than min')
|
||||
exit(1)
|
||||
}
|
||||
return min + rng.u64n(max - min)
|
||||
}
|
||||
|
||||
// int returns a 32-bit signed (possibly negative) `int`.
|
||||
[inline]
|
||||
pub fn (mut rng PCG32RNG) int() int {
|
||||
return int(rng.u32())
|
||||
}
|
||||
|
||||
// i64 returns a 64-bit signed (possibly negative) `i64`.
|
||||
[inline]
|
||||
pub fn (mut rng PCG32RNG) i64() i64 {
|
||||
return i64(rng.u64())
|
||||
}
|
||||
|
||||
// int31 returns a 31-bit positive pseudorandom `int`.
|
||||
[inline]
|
||||
pub fn (mut rng PCG32RNG) int31() int {
|
||||
return int(rng.u32() >> 1)
|
||||
}
|
||||
|
||||
// int63 returns a 63-bit positive pseudorandom `i64`.
|
||||
[inline]
|
||||
pub fn (mut rng PCG32RNG) int63() i64 {
|
||||
return i64(rng.u64() >> 1)
|
||||
}
|
||||
|
||||
// intn returns a 32-bit positive `int` in range `[0, max)`.
|
||||
[inline]
|
||||
pub fn (mut rng PCG32RNG) intn(max int) int {
|
||||
if max <= 0 {
|
||||
eprintln('max has to be positive.')
|
||||
exit(1)
|
||||
}
|
||||
return int(rng.u32n(u32(max)))
|
||||
}
|
||||
|
||||
// i64n returns a 64-bit positive `i64` in range `[0, max)`.
|
||||
[inline]
|
||||
pub fn (mut rng PCG32RNG) i64n(max i64) i64 {
|
||||
if max <= 0 {
|
||||
eprintln('max has to be positive.')
|
||||
exit(1)
|
||||
}
|
||||
return i64(rng.u64n(u64(max)))
|
||||
}
|
||||
|
||||
// int_in_range returns a 32-bit positive `int` in range `[0, max)`.
|
||||
[inline]
|
||||
pub fn (mut rng PCG32RNG) int_in_range(min int, max int) int {
|
||||
if max <= min {
|
||||
eprintln('max must be greater than min.')
|
||||
exit(1)
|
||||
}
|
||||
return min + rng.intn(max - min)
|
||||
}
|
||||
|
||||
// i64_in_range returns a 64-bit positive `i64` in range `[0, max)`.
|
||||
[inline]
|
||||
pub fn (mut rng PCG32RNG) i64_in_range(min i64, max i64) i64 {
|
||||
if max <= min {
|
||||
eprintln('max must be greater than min.')
|
||||
exit(1)
|
||||
}
|
||||
return min + rng.i64n(max - min)
|
||||
}
|
||||
|
||||
// f32 returns a pseudorandom `f32` value in range `[0, 1)`.
|
||||
[inline]
|
||||
pub fn (mut rng PCG32RNG) f32() f32 {
|
||||
return f32(rng.u32()) / constants.max_u32_as_f32
|
||||
}
|
||||
|
||||
// f64 returns a pseudorandom `f64` value in range `[0, 1)`.
|
||||
[inline]
|
||||
pub fn (mut rng PCG32RNG) f64() f64 {
|
||||
return f64(rng.u64()) / constants.max_u64_as_f64
|
||||
}
|
||||
|
||||
// f32n returns a pseudorandom `f32` value in range `[0, max)`.
|
||||
[inline]
|
||||
pub fn (mut rng PCG32RNG) f32n(max f32) f32 {
|
||||
if max <= 0 {
|
||||
eprintln('max has to be positive.')
|
||||
exit(1)
|
||||
}
|
||||
return rng.f32() * max
|
||||
}
|
||||
|
||||
// f64n returns a pseudorandom `f64` value in range `[0, max)`.
|
||||
[inline]
|
||||
pub fn (mut rng PCG32RNG) f64n(max f64) f64 {
|
||||
if max <= 0 {
|
||||
eprintln('max has to be positive.')
|
||||
exit(1)
|
||||
}
|
||||
return rng.f64() * max
|
||||
}
|
||||
|
||||
// f32_in_range returns a pseudorandom `f32` in range `[min, max)`.
|
||||
[inline]
|
||||
pub fn (mut rng PCG32RNG) f32_in_range(min f32, max f32) f32 {
|
||||
if max <= min {
|
||||
eprintln('max must be greater than min')
|
||||
exit(1)
|
||||
}
|
||||
return min + rng.f32n(max - min)
|
||||
}
|
||||
|
||||
// i64_in_range returns a pseudorandom `i64` in range `[min, max)`.
|
||||
[inline]
|
||||
pub fn (mut rng PCG32RNG) f64_in_range(min f64, max f64) f64 {
|
||||
if max <= min {
|
||||
eprintln('max must be greater than min')
|
||||
exit(1)
|
||||
}
|
||||
return min + rng.f64n(max - min)
|
||||
}
|
||||
|
||||
// free should be called when the generator is no longer needed
|
||||
[unsafe]
|
||||
pub fn (mut rng PCG32RNG) free() {
|
||||
|
||||
@ -17,10 +17,10 @@ const (
|
||||
|
||||
fn gen_randoms(seed_data []u32, bound int) []u32 {
|
||||
mut randoms := []u32{len: 20}
|
||||
mut rng := pcg32.PCG32RNG{}
|
||||
mut rng := &rand.PRNG(&pcg32.PCG32RNG{})
|
||||
rng.seed(seed_data)
|
||||
for i in 0 .. 20 {
|
||||
randoms[i] = rng.u32n(u32(bound))
|
||||
randoms[i] = rng.u32n(u32(bound)) or { panic("Couldn't obtain u32") }
|
||||
}
|
||||
return randoms
|
||||
}
|
||||
@ -38,40 +38,29 @@ fn test_pcg32_reproducibility() {
|
||||
}
|
||||
}
|
||||
|
||||
// TODO: use the `in` syntax and remove this function
|
||||
// after generics has been completely implemented
|
||||
fn found(value u64, arr []u64) bool {
|
||||
for item in arr {
|
||||
if value == item {
|
||||
return true
|
||||
}
|
||||
}
|
||||
return false
|
||||
}
|
||||
|
||||
fn test_pcg32_variability() {
|
||||
// If this test fails and if it is certainly not the implementation
|
||||
// at fault, try changing the seed values. Repeated values are
|
||||
// improbable but not impossible.
|
||||
for seed in seeds {
|
||||
mut rng := pcg32.PCG32RNG{}
|
||||
mut rng := &rand.PRNG(&pcg32.PCG32RNG{})
|
||||
rng.seed(seed)
|
||||
mut values := []u64{cap: value_count}
|
||||
for i in 0 .. value_count {
|
||||
value := rng.u64()
|
||||
assert !found(value, values)
|
||||
assert value !in values
|
||||
assert values.len == i
|
||||
values << value
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
fn check_uniformity_u64(mut rng pcg32.PCG32RNG, range u64) {
|
||||
fn check_uniformity_u64(mut rng rand.PRNG, range u64) {
|
||||
range_f64 := f64(range)
|
||||
expected_mean := range_f64 / 2.0
|
||||
mut variance := 0.0
|
||||
for _ in 0 .. sample_size {
|
||||
diff := f64(rng.u64n(range)) - expected_mean
|
||||
diff := f64(rng.u64n(range) or { panic("Couldn't obtain u64") }) - expected_mean
|
||||
variance += diff * diff
|
||||
}
|
||||
variance /= sample_size - 1
|
||||
@ -84,7 +73,7 @@ fn check_uniformity_u64(mut rng pcg32.PCG32RNG, range u64) {
|
||||
fn test_pcg32_uniformity_u64() {
|
||||
ranges := [14019545, 80240, 130]
|
||||
for seed in seeds {
|
||||
mut rng := pcg32.PCG32RNG{}
|
||||
mut rng := &rand.PRNG(&pcg32.PCG32RNG{})
|
||||
rng.seed(seed)
|
||||
for range in ranges {
|
||||
check_uniformity_u64(mut rng, u64(range))
|
||||
@ -92,7 +81,7 @@ fn test_pcg32_uniformity_u64() {
|
||||
}
|
||||
}
|
||||
|
||||
fn check_uniformity_f64(mut rng pcg32.PCG32RNG) {
|
||||
fn check_uniformity_f64(mut rng rand.PRNG) {
|
||||
expected_mean := 0.5
|
||||
mut variance := 0.0
|
||||
for _ in 0 .. sample_size {
|
||||
@ -109,7 +98,7 @@ fn check_uniformity_f64(mut rng pcg32.PCG32RNG) {
|
||||
fn test_pcg32_uniformity_f64() {
|
||||
// The f64 version
|
||||
for seed in seeds {
|
||||
mut rng := pcg32.PCG32RNG{}
|
||||
mut rng := &rand.PRNG(&pcg32.PCG32RNG{})
|
||||
rng.seed(seed)
|
||||
check_uniformity_f64(mut rng)
|
||||
}
|
||||
@ -118,10 +107,10 @@ fn test_pcg32_uniformity_f64() {
|
||||
fn test_pcg32_u32n() {
|
||||
max := u32(16384)
|
||||
for seed in seeds {
|
||||
mut rng := pcg32.PCG32RNG{}
|
||||
mut rng := &rand.PRNG(&pcg32.PCG32RNG{})
|
||||
rng.seed(seed)
|
||||
for _ in 0 .. range_limit {
|
||||
value := rng.u32n(max)
|
||||
value := rng.u32n(max) or { panic("Couldn't obtain u32") }
|
||||
assert value >= 0
|
||||
assert value < max
|
||||
}
|
||||
@ -131,10 +120,10 @@ fn test_pcg32_u32n() {
|
||||
fn test_pcg32_u64n() {
|
||||
max := u64(379091181005)
|
||||
for seed in seeds {
|
||||
mut rng := pcg32.PCG32RNG{}
|
||||
mut rng := &rand.PRNG(&pcg32.PCG32RNG{})
|
||||
rng.seed(seed)
|
||||
for _ in 0 .. range_limit {
|
||||
value := rng.u64n(max)
|
||||
value := rng.u64n(max) or { panic("Couldn't obtain u64") }
|
||||
assert value >= 0
|
||||
assert value < max
|
||||
}
|
||||
@ -145,10 +134,12 @@ fn test_pcg32_u32_in_range() {
|
||||
max := u32(484468466)
|
||||
min := u32(316846)
|
||||
for seed in seeds {
|
||||
mut rng := pcg32.PCG32RNG{}
|
||||
mut rng := &rand.PRNG(&pcg32.PCG32RNG{})
|
||||
rng.seed(seed)
|
||||
for _ in 0 .. range_limit {
|
||||
value := rng.u32_in_range(u32(min), u32(max))
|
||||
value := rng.u32_in_range(u32(min), u32(max)) or {
|
||||
panic("Couldn't obtain u32 in range")
|
||||
}
|
||||
assert value >= min
|
||||
assert value < max
|
||||
}
|
||||
@ -159,10 +150,10 @@ fn test_pcg32_u64_in_range() {
|
||||
max := u64(216468454685163)
|
||||
min := u64(6848646868)
|
||||
for seed in seeds {
|
||||
mut rng := pcg32.PCG32RNG{}
|
||||
mut rng := &rand.PRNG(&pcg32.PCG32RNG{})
|
||||
rng.seed(seed)
|
||||
for _ in 0 .. range_limit {
|
||||
value := rng.u64_in_range(min, max)
|
||||
value := rng.u64_in_range(min, max) or { panic("Couldn't obtain u64 in range") }
|
||||
assert value >= min
|
||||
assert value < max
|
||||
}
|
||||
@ -173,7 +164,7 @@ fn test_pcg32_int31() {
|
||||
max_u31 := int(0x7FFFFFFF)
|
||||
sign_mask := int(0x80000000)
|
||||
for seed in seeds {
|
||||
mut rng := pcg32.PCG32RNG{}
|
||||
mut rng := &rand.PRNG(&pcg32.PCG32RNG{})
|
||||
rng.seed(seed)
|
||||
for _ in 0 .. range_limit {
|
||||
value := rng.int31()
|
||||
@ -189,7 +180,7 @@ fn test_pcg32_int63() {
|
||||
max_u63 := i64(0x7FFFFFFFFFFFFFFF)
|
||||
sign_mask := i64(0x8000000000000000)
|
||||
for seed in seeds {
|
||||
mut rng := pcg32.PCG32RNG{}
|
||||
mut rng := &rand.PRNG(&pcg32.PCG32RNG{})
|
||||
rng.seed(seed)
|
||||
for _ in 0 .. range_limit {
|
||||
value := rng.int63()
|
||||
@ -203,10 +194,10 @@ fn test_pcg32_int63() {
|
||||
fn test_pcg32_intn() {
|
||||
max := 2525642
|
||||
for seed in seeds {
|
||||
mut rng := pcg32.PCG32RNG{}
|
||||
mut rng := &rand.PRNG(&pcg32.PCG32RNG{})
|
||||
rng.seed(seed)
|
||||
for _ in 0 .. range_limit {
|
||||
value := rng.intn(max)
|
||||
value := rng.intn(max) or { panic("Couldn't obtain int") }
|
||||
assert value >= 0
|
||||
assert value < max
|
||||
}
|
||||
@ -216,10 +207,10 @@ fn test_pcg32_intn() {
|
||||
fn test_pcg32_i64n() {
|
||||
max := i64(3246727724653636)
|
||||
for seed in seeds {
|
||||
mut rng := pcg32.PCG32RNG{}
|
||||
mut rng := &rand.PRNG(&pcg32.PCG32RNG{})
|
||||
rng.seed(seed)
|
||||
for _ in 0 .. range_limit {
|
||||
value := rng.i64n(max)
|
||||
value := rng.i64n(max) or { panic("Couldn't obtain i64") }
|
||||
assert value >= 0
|
||||
assert value < max
|
||||
}
|
||||
@ -230,10 +221,10 @@ fn test_pcg32_int_in_range() {
|
||||
min := -4252
|
||||
max := 1034
|
||||
for seed in seeds {
|
||||
mut rng := pcg32.PCG32RNG{}
|
||||
mut rng := &rand.PRNG(&pcg32.PCG32RNG{})
|
||||
rng.seed(seed)
|
||||
for _ in 0 .. range_limit {
|
||||
value := rng.int_in_range(min, max)
|
||||
value := rng.int_in_range(min, max) or { panic("Couldn't obtain int in range") }
|
||||
assert value >= min
|
||||
assert value < max
|
||||
}
|
||||
@ -244,10 +235,10 @@ fn test_pcg32_i64_in_range() {
|
||||
min := i64(-24095)
|
||||
max := i64(324058)
|
||||
for seed in seeds {
|
||||
mut rng := pcg32.PCG32RNG{}
|
||||
mut rng := &rand.PRNG(&pcg32.PCG32RNG{})
|
||||
rng.seed(seed)
|
||||
for _ in 0 .. range_limit {
|
||||
value := rng.i64_in_range(min, max)
|
||||
value := rng.i64_in_range(min, max) or { panic("Couldn't obtain i64 in range") }
|
||||
assert value >= min
|
||||
assert value < max
|
||||
}
|
||||
@ -256,7 +247,7 @@ fn test_pcg32_i64_in_range() {
|
||||
|
||||
fn test_pcg32_f32() {
|
||||
for seed in seeds {
|
||||
mut rng := pcg32.PCG32RNG{}
|
||||
mut rng := &rand.PRNG(&pcg32.PCG32RNG{})
|
||||
rng.seed(seed)
|
||||
for _ in 0 .. range_limit {
|
||||
value := rng.f32()
|
||||
@ -268,7 +259,7 @@ fn test_pcg32_f32() {
|
||||
|
||||
fn test_pcg32_f64() {
|
||||
for seed in seeds {
|
||||
mut rng := pcg32.PCG32RNG{}
|
||||
mut rng := &rand.PRNG(&pcg32.PCG32RNG{})
|
||||
rng.seed(seed)
|
||||
for _ in 0 .. range_limit {
|
||||
value := rng.f64()
|
||||
@ -281,10 +272,10 @@ fn test_pcg32_f64() {
|
||||
fn test_pcg32_f32n() {
|
||||
max := f32(357.0)
|
||||
for seed in seeds {
|
||||
mut rng := pcg32.PCG32RNG{}
|
||||
mut rng := &rand.PRNG(&pcg32.PCG32RNG{})
|
||||
rng.seed(seed)
|
||||
for _ in 0 .. range_limit {
|
||||
value := rng.f32n(max)
|
||||
value := rng.f32n(max) or { panic("Couldn't obtain f32") }
|
||||
assert value >= 0.0
|
||||
assert value < max
|
||||
}
|
||||
@ -294,10 +285,10 @@ fn test_pcg32_f32n() {
|
||||
fn test_pcg32_f64n() {
|
||||
max := 1.52e6
|
||||
for seed in seeds {
|
||||
mut rng := pcg32.PCG32RNG{}
|
||||
mut rng := &rand.PRNG(&pcg32.PCG32RNG{})
|
||||
rng.seed(seed)
|
||||
for _ in 0 .. range_limit {
|
||||
value := rng.f64n(max)
|
||||
value := rng.f64n(max) or { panic("Couldn't obtain f64") }
|
||||
assert value >= 0.0
|
||||
assert value < max
|
||||
}
|
||||
@ -308,10 +299,10 @@ fn test_pcg32_f32_in_range() {
|
||||
min := f32(-24.0)
|
||||
max := f32(125.0)
|
||||
for seed in seeds {
|
||||
mut rng := pcg32.PCG32RNG{}
|
||||
mut rng := &rand.PRNG(&pcg32.PCG32RNG{})
|
||||
rng.seed(seed)
|
||||
for _ in 0 .. range_limit {
|
||||
value := rng.f32_in_range(min, max)
|
||||
value := rng.f32_in_range(min, max) or { panic("Couldn't obtain f32 in range") }
|
||||
assert value >= min
|
||||
assert value < max
|
||||
}
|
||||
@ -322,10 +313,10 @@ fn test_pcg32_f64_in_range() {
|
||||
min := -548.7
|
||||
max := 5015.2
|
||||
for seed in seeds {
|
||||
mut rng := pcg32.PCG32RNG{}
|
||||
mut rng := &rand.PRNG(&pcg32.PCG32RNG{})
|
||||
rng.seed(seed)
|
||||
for _ in 0 .. range_limit {
|
||||
value := rng.f64_in_range(min, max)
|
||||
value := rng.f64_in_range(min, max) or { panic("Couldn't obtain f64 in range") }
|
||||
assert value >= min
|
||||
assert value < max
|
||||
}
|
||||
@ -333,5 +324,5 @@ fn test_pcg32_f64_in_range() {
|
||||
}
|
||||
|
||||
fn test_change_default_random_generator() {
|
||||
rand.set_rng(pcg32.PCG32RNG{})
|
||||
rand.set_rng(&rand.PRNG(&pcg32.PCG32RNG{}))
|
||||
}
|
||||
|
||||
Reference in New Issue
Block a user