rand: simplify rand.PRNG, move to optional types for error handling (#13570)

2023-08-10 21:13:21 +03:00 · 2022-02-23 16:06:14 +05:30
parent 5c0b7b0d05
commit 114a341f5f
49 changed files with 609 additions and 1586 deletions
--- a/vlib/rand/mt19937/mt19937_test.v
+++ b/vlib/rand/mt19937/mt19937_test.v
@@ -1,4 +1,5 @@
 import math
+import rand
 import rand.mt19937
 import rand.seed

@@ -15,7 +16,7 @@ const (
 )

 fn mt19937_basic_test() {
-	mut rng := mt19937.MT19937RNG{}
+	mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
 	rng.seed([u32(0xdeadbeef)])
 	target := [u32(956529277), 3842322136, 3319553134, 1843186657, 2704993644, 595827513, 938518626,
 		1676224337, 3221315650, 1819026461]
@@ -27,10 +28,11 @@ fn mt19937_basic_test() {
 fn gen_randoms(seed_data []u32, bound int) []u64 {
 	bound_u64 := u64(bound)
 	mut randoms := []u64{len: (20)}
-	mut rnd := mt19937.MT19937RNG{}
+	x := mt19937.MT19937RNG{}
+	mut rnd := rand.PRNG(x)
 	rnd.seed(seed_data)
 	for i in 0 .. 20 {
-		randoms[i] = rnd.u64n(bound_u64)
+		randoms[i] = rnd.u64n(bound_u64) or { panic("Couldn't obtain random u64") }
 	}
 	return randoms
 }
@@ -46,40 +48,29 @@ fn test_mt19937_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_mt19937_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 := mt19937.MT19937RNG{}
+		mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
 		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 mt19937.MT19937RNG, 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 random u64") }) - expected_mean
 		variance += diff * diff
 	}
 	variance /= sample_size - 1
@@ -92,7 +83,7 @@ fn check_uniformity_u64(mut rng mt19937.MT19937RNG, range u64) {
 fn test_mt19937_uniformity_u64() {
 	ranges := [14019545, 80240, 130]
 	for seed in seeds {
-		mut rng := mt19937.MT19937RNG{}
+		mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
 		rng.seed(seed)
 		for range in ranges {
 			check_uniformity_u64(mut rng, u64(range))
@@ -100,7 +91,7 @@ fn test_mt19937_uniformity_u64() {
 	}
 }

-fn check_uniformity_f64(mut rng mt19937.MT19937RNG) {
+fn check_uniformity_f64(mut rng rand.PRNG) {
 	expected_mean := 0.5
 	mut variance := 0.0
 	for _ in 0 .. sample_size {
@@ -117,7 +108,7 @@ fn check_uniformity_f64(mut rng mt19937.MT19937RNG) {
 fn test_mt19937_uniformity_f64() {
 	// The f64 version
 	for seed in seeds {
-		mut rng := mt19937.MT19937RNG{}
+		mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
 		rng.seed(seed)
 		check_uniformity_f64(mut rng)
 	}
@@ -126,10 +117,10 @@ fn test_mt19937_uniformity_f64() {
 fn test_mt19937_u32n() {
 	max := u32(16384)
 	for seed in seeds {
-		mut rng := mt19937.MT19937RNG{}
+		mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
 		rng.seed(seed)
 		for _ in 0 .. range_limit {
-			value := rng.u32n(max)
+			value := rng.u32n(max) or { panic("Couldn't obtain random u32") }
 			assert value >= 0
 			assert value < max
 		}
@@ -139,10 +130,10 @@ fn test_mt19937_u32n() {
 fn test_mt19937_u64n() {
 	max := u64(379091181005)
 	for seed in seeds {
-		mut rng := mt19937.MT19937RNG{}
+		mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
 		rng.seed(seed)
 		for _ in 0 .. range_limit {
-			value := rng.u64n(max)
+			value := rng.u64n(max) or { panic("Couldn't obtain random u64") }
 			assert value >= 0
 			assert value < max
 		}
@@ -153,10 +144,10 @@ fn test_mt19937_u32_in_range() {
 	max := u32(484468466)
 	min := u32(316846)
 	for seed in seeds {
-		mut rng := mt19937.MT19937RNG{}
+		mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
 		rng.seed(seed)
 		for _ in 0 .. range_limit {
-			value := rng.u32_in_range(min, max)
+			value := rng.u32_in_range(min, max) or { panic("Couldn't obtain random u32 in range.") }
 			assert value >= min
 			assert value < max
 		}
@@ -167,10 +158,10 @@ fn test_mt19937_u64_in_range() {
 	max := u64(216468454685163)
 	min := u64(6848646868)
 	for seed in seeds {
-		mut rng := mt19937.MT19937RNG{}
+		mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
 		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 random u64 in range.") }
 			assert value >= min
 			assert value < max
 		}
@@ -181,7 +172,7 @@ fn test_mt19937_int31() {
 	max_u31 := int(0x7FFFFFFF)
 	sign_mask := int(0x80000000)
 	for seed in seeds {
-		mut rng := mt19937.MT19937RNG{}
+		mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
 		rng.seed(seed)
 		for _ in 0 .. range_limit {
 			value := rng.int31()
@@ -197,7 +188,7 @@ fn test_mt19937_int63() {
 	max_u63 := i64(0x7FFFFFFFFFFFFFFF)
 	sign_mask := i64(0x8000000000000000)
 	for seed in seeds {
-		mut rng := mt19937.MT19937RNG{}
+		mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
 		rng.seed(seed)
 		for _ in 0 .. range_limit {
 			value := rng.int63()
@@ -211,10 +202,10 @@ fn test_mt19937_int63() {
 fn test_mt19937_intn() {
 	max := 2525642
 	for seed in seeds {
-		mut rng := mt19937.MT19937RNG{}
+		mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
 		rng.seed(seed)
 		for _ in 0 .. range_limit {
-			value := rng.intn(max)
+			value := rng.intn(max) or { panic("Couldn't obtain random int") }
 			assert value >= 0
 			assert value < max
 		}
@@ -224,10 +215,10 @@ fn test_mt19937_intn() {
 fn test_mt19937_i64n() {
 	max := i64(3246727724653636)
 	for seed in seeds {
-		mut rng := mt19937.MT19937RNG{}
+		mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
 		rng.seed(seed)
 		for _ in 0 .. range_limit {
-			value := rng.i64n(max)
+			value := rng.i64n(max) or { panic("Couldn't obtain random i64") }
 			assert value >= 0
 			assert value < max
 		}
@@ -238,10 +229,10 @@ fn test_mt19937_int_in_range() {
 	min := -4252
 	max := 1034
 	for seed in seeds {
-		mut rng := mt19937.MT19937RNG{}
+		mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
 		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 random int in range.") }
 			assert value >= min
 			assert value < max
 		}
@@ -252,10 +243,10 @@ fn test_mt19937_i64_in_range() {
 	min := i64(-24095)
 	max := i64(324058)
 	for seed in seeds {
-		mut rng := mt19937.MT19937RNG{}
+		mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
 		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 random i64 in range.") }
 			assert value >= min
 			assert value < max
 		}
@@ -264,7 +255,7 @@ fn test_mt19937_i64_in_range() {

 fn test_mt19937_f32() {
 	for seed in seeds {
-		mut rng := mt19937.MT19937RNG{}
+		mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
 		rng.seed(seed)
 		for _ in 0 .. range_limit {
 			value := rng.f32()
@@ -276,7 +267,7 @@ fn test_mt19937_f32() {

 fn test_mt19937_f64() {
 	for seed in seeds {
-		mut rng := mt19937.MT19937RNG{}
+		mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
 		rng.seed(seed)
 		for _ in 0 .. range_limit {
 			value := rng.f64()
@@ -289,10 +280,10 @@ fn test_mt19937_f64() {
 fn test_mt19937_f32n() {
 	max := f32(357.0)
 	for seed in seeds {
-		mut rng := mt19937.MT19937RNG{}
+		mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
 		rng.seed(seed)
 		for _ in 0 .. range_limit {
-			value := rng.f32n(max)
+			value := rng.f32n(max) or { panic("Couldn't obtain random f32") }
 			assert value >= 0.0
 			assert value < max
 		}
@@ -302,10 +293,10 @@ fn test_mt19937_f32n() {
 fn test_mt19937_f64n() {
 	max := 1.52e6
 	for seed in seeds {
-		mut rng := mt19937.MT19937RNG{}
+		mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
 		rng.seed(seed)
 		for _ in 0 .. range_limit {
-			value := rng.f64n(max)
+			value := rng.f64n(max) or { panic("Couldn't obtain random f64") }
 			assert value >= 0.0
 			assert value < max
 		}
@@ -316,10 +307,10 @@ fn test_mt19937_f32_in_range() {
 	min := f32(-24.0)
 	max := f32(125.0)
 	for seed in seeds {
-		mut rng := mt19937.MT19937RNG{}
+		mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
 		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 random f32 in range.") }
 			assert value >= min
 			assert value < max
 		}
@@ -330,10 +321,10 @@ fn test_mt19937_f64_in_range() {
 	min := -548.7
 	max := 5015.2
 	for seed in seeds {
-		mut rng := mt19937.MT19937RNG{}
+		mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
 		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 random f64 in range.") }
 			assert value >= min
 			assert value < max
 		}