From 97103f680a8f5d3ce45e2a53ef204c6a502b59f7 Mon Sep 17 00:00:00 2001
From: Subhomoy Haldar <hungrybluedev@gmail.com>
Date: Tue, 26 Jan 2021 19:25:09 +0530
Subject: [PATCH] rand: separate rand.util and rand.seed submodules (#8353)

---
 vlib/io/util/util.v                    | 18 ++++--------
 vlib/rand/mt19937/mt19937.v            | 32 ++++++++++-----------
 vlib/rand/mt19937/mt19937_test.v       |  6 ++--
 vlib/rand/musl/musl_rng.v              |  3 +-
 vlib/rand/musl/musl_rng_test.v         |  6 ++--
 vlib/rand/pcg32/pcg32.v                |  5 ++--
 vlib/rand/pcg32/pcg32_test.v           |  4 +--
 vlib/rand/rand.v                       | 18 ++++++------
 vlib/rand/random_identifiers_test.v    |  2 +-
 vlib/rand/seed/seed.v                  | 40 ++++++++++++++++++++++++++
 vlib/rand/splitmix64/splitmix64.v      |  3 +-
 vlib/rand/splitmix64/splitmix64_test.v |  6 ++--
 vlib/rand/sys/system_rng.c.v           | 17 +++++------
 vlib/rand/util/util.v                  | 36 -----------------------
 vlib/rand/wyrand/wyrand.v              |  9 +++---
 vlib/rand/wyrand/wyrand_test.v         |  6 ++--
 16 files changed, 107 insertions(+), 104 deletions(-)
 create mode 100644 vlib/rand/seed/seed.v

diff --git a/vlib/io/util/util.v b/vlib/io/util/util.v
index 44eaedf26b..ff4922aed0 100644
--- a/vlib/io/util/util.v
+++ b/vlib/io/util/util.v
@@ -3,7 +3,7 @@ module util
 import os
 import rand
 import rand.wyrand
-import rand.util as rutil
+import rand.seed as rseed
 
 const (
 	retries = 10000
@@ -26,9 +26,7 @@ pub fn temp_file(tfo TempFileOptions) ?(os.File, string) {
 	}
 	d = d.trim_right(os.path_separator)
 	mut rng := rand.new_default(rand.PRNGConfigStruct{})
-	prefix, suffix := prefix_and_suffix(tfo.pattern) or {
-		return error(@FN + ' ' + err)
-	}
+	prefix, suffix := prefix_and_suffix(tfo.pattern) or { return error(@FN + ' ' + err) }
 	for retry := 0; retry < retries; retry++ {
 		path := os.join_path(d, prefix + random_number(mut rng) + suffix)
 		mut mode := 'rw+'
@@ -36,7 +34,7 @@ pub fn temp_file(tfo TempFileOptions) ?(os.File, string) {
 			mode = 'w+'
 		}
 		mut file := os.open_file(path, mode, 0o600) or {
-			rng.seed(rutil.time_seed_array(2))
+			rng.seed(rseed.time_seed_array(2))
 			continue
 		}
 		if os.exists(path) && os.is_file(path) {
@@ -64,13 +62,11 @@ pub fn temp_dir(tdo TempFileOptions) ?string {
 	}
 	d = d.trim_right(os.path_separator)
 	mut rng := rand.new_default(rand.PRNGConfigStruct{})
-	prefix, suffix := prefix_and_suffix(tdo.pattern) or {
-		return error(@FN + ' ' + err)
-	}
+	prefix, suffix := prefix_and_suffix(tdo.pattern) or { return error(@FN + ' ' + err) }
 	for retry := 0; retry < retries; retry++ {
 		path := os.join_path(d, prefix + random_number(mut rng) + suffix)
 		os.mkdir_all(path) or {
-			rng.seed(rutil.time_seed_array(2))
+			rng.seed(rseed.time_seed_array(2))
 			continue
 		}
 		if os.is_dir(path) && os.exists(path) {
@@ -96,9 +92,7 @@ fn prefix_and_suffix(pattern string) ?(string, string) {
 	if pat.contains(os.path_separator) {
 		return error('pattern cannot contain path separators ($os.path_separator).')
 	}
-	pos := pat.last_index('*') or {
-		-1
-	}
+	pos := pat.last_index('*') or { -1 }
 	mut prefix := ''
 	mut suffix := ''
 	if pos != -1 {
diff --git a/vlib/rand/mt19937/mt19937.v b/vlib/rand/mt19937/mt19937.v
index e337627d52..f509642db4 100644
--- a/vlib/rand/mt19937/mt19937.v
+++ b/vlib/rand/mt19937/mt19937.v
@@ -4,7 +4,7 @@
 module mt19937
 
 import math.bits
-import rand.util
+import rand.seed
 
 /*
 C++ functions for MT19937, with initialization improved 2002/2/10.
@@ -59,8 +59,8 @@ const (
 // MT19937RNG is generator that uses the Mersenne Twister algorithm with period 2^19937.
 pub struct MT19937RNG {
 mut:
-	state    []u64 = calculate_state(util.time_seed_array(2), mut []u64{len: nn})
-	mti      int = nn
+	state    []u64 = calculate_state(seed.time_seed_array(2), mut []u64{len: mt19937.nn})
+	mti      int   = mt19937.nn
 	next_rnd u32
 	has_next bool
 }
@@ -70,7 +70,7 @@ fn calculate_state(seed_data []u32, mut state []u64) []u64 {
 	lo := u64(seed_data[0])
 	hi := u64(seed_data[1])
 	state[0] = u64((hi << 32) | lo)
-	for j := 1; j < nn; j++ {
+	for j := 1; j < mt19937.nn; j++ {
 		state[j] = u64(6364136223846793005) * (state[j - 1] ^ (state[j - 1] >> 62)) + u64(j)
 	}
 	return *state
@@ -84,7 +84,7 @@ pub fn (mut rng MT19937RNG) seed(seed_data []u32) {
 		exit(1)
 	}
 	rng.state = calculate_state(seed_data, mut rng.state)
-	rng.mti = nn
+	rng.mti = mt19937.nn
 	rng.next_rnd = 0
 	rng.has_next = false
 }
@@ -105,21 +105,21 @@ pub fn (mut rng MT19937RNG) u32() u32 {
 // u64 returns a pseudorandom 64bit int in range `[0, 2⁶⁴)`.
 [inline]
 pub fn (mut rng MT19937RNG) u64() u64 {
-	mag01 := [u64(0), u64(matrix_a)]
+	mag01 := [u64(0), u64(mt19937.matrix_a)]
 	mut x := u64(0)
 	mut i := int(0)
-	if rng.mti >= nn {
-		for i = 0; i < nn - mm; i++ {
-			x = (rng.state[i] & um) | (rng.state[i + 1] & lm)
-			rng.state[i] = rng.state[i + mm] ^ (x >> 1) ^ mag01[int(x & 1)]
+	if rng.mti >= mt19937.nn {
+		for i = 0; i < mt19937.nn - mt19937.mm; i++ {
+			x = (rng.state[i] & mt19937.um) | (rng.state[i + 1] & mt19937.lm)
+			rng.state[i] = rng.state[i + mt19937.mm] ^ (x >> 1) ^ mag01[int(x & 1)]
 		}
-		for i < nn - 1 {
-			x = (rng.state[i] & um) | (rng.state[i + 1] & lm)
-			rng.state[i] = rng.state[i + (mm - nn)] ^ (x >> 1) ^ mag01[int(x & 1)]
+		for i < mt19937.nn - 1 {
+			x = (rng.state[i] & mt19937.um) | (rng.state[i + 1] & mt19937.lm)
+			rng.state[i] = rng.state[i + (mt19937.mm - mt19937.nn)] ^ (x >> 1) ^ mag01[int(x & 1)]
 			i++
 		}
-		x = (rng.state[nn - 1] & um) | (rng.state[0] & lm)
-		rng.state[nn - 1] = rng.state[mm - 1] ^ (x >> 1) ^ mag01[int(x & 1)]
+		x = (rng.state[mt19937.nn - 1] & mt19937.um) | (rng.state[0] & mt19937.lm)
+		rng.state[mt19937.nn - 1] = rng.state[mt19937.mm - 1] ^ (x >> 1) ^ mag01[int(x & 1)]
 		rng.mti = 0
 	}
 	x = rng.state[rng.mti]
@@ -279,7 +279,7 @@ pub fn (mut rng MT19937RNG) f32() f32 {
 // f64 returns 64bit real (`f64`) in range `[0, 1)`.
 [inline]
 pub fn (mut rng MT19937RNG) f64() f64 {
-	return f64(rng.u64() >> 11) * inv_f64_limit
+	return f64(rng.u64() >> 11) * mt19937.inv_f64_limit
 }
 
 // f32n returns a 32bit real (`f32`) in range [0, max)`.
diff --git a/vlib/rand/mt19937/mt19937_test.v b/vlib/rand/mt19937/mt19937_test.v
index cc3e6a6e6d..02e9daf83c 100644
--- a/vlib/rand/mt19937/mt19937_test.v
+++ b/vlib/rand/mt19937/mt19937_test.v
@@ -1,6 +1,6 @@
 import math
 import rand.mt19937
-import rand.util
+import rand.seed
 
 const (
 	range_limit = 40
@@ -26,7 +26,7 @@ fn mt19937_basic_test() {
 
 fn gen_randoms(seed_data []u32, bound int) []u64 {
 	bound_u64 := u64(bound)
-	mut randoms := []u64{len:(20)}
+	mut randoms := []u64{len: (20)}
 	mut rnd := mt19937.MT19937RNG{}
 	rnd.seed(seed_data)
 	for i in 0 .. 20 {
@@ -36,7 +36,7 @@ fn gen_randoms(seed_data []u32, bound int) []u64 {
 }
 
 fn test_mt19937_reproducibility() {
-	seed_data := util.time_seed_array(2)
+	seed_data := seed.time_seed_array(2)
 	randoms1 := gen_randoms(seed_data, 1000)
 	randoms2 := gen_randoms(seed_data, 1000)
 	assert randoms1.len == randoms2.len
diff --git a/vlib/rand/musl/musl_rng.v b/vlib/rand/musl/musl_rng.v
index 55d07a3c37..998428e896 100644
--- a/vlib/rand/musl/musl_rng.v
+++ b/vlib/rand/musl/musl_rng.v
@@ -4,12 +4,13 @@
 module musl
 
 import math.bits
+import rand.seed
 import rand.util
 
 // MuslRNG ported from https://git.musl-libc.org/cgit/musl/tree/src/prng/rand_r.c
 pub struct MuslRNG {
 mut:
-	state u32 = util.time_seed_32()
+	state u32 = seed.time_seed_32()
 }
 
 // seed sets the current random state based on `seed_data`.
diff --git a/vlib/rand/musl/musl_rng_test.v b/vlib/rand/musl/musl_rng_test.v
index c0f6ea0a7d..e6406f90bd 100644
--- a/vlib/rand/musl/musl_rng_test.v
+++ b/vlib/rand/musl/musl_rng_test.v
@@ -1,6 +1,6 @@
 import math
 import rand.musl
-import rand.util
+import rand.seed
 
 const (
 	range_limit = 40
@@ -16,7 +16,7 @@ const (
 
 fn gen_randoms(seed_data []u32, bound int) []u64 {
 	bound_u64 := u64(bound)
-	mut randoms := []u64{len:(20)}
+	mut randoms := []u64{len: (20)}
 	mut rnd := musl.MuslRNG{}
 	rnd.seed(seed_data)
 	for i in 0 .. 20 {
@@ -26,7 +26,7 @@ fn gen_randoms(seed_data []u32, bound int) []u64 {
 }
 
 fn test_musl_reproducibility() {
-	seed_data := util.time_seed_array(1)
+	seed_data := seed.time_seed_array(1)
 	randoms1 := gen_randoms(seed_data, 1000)
 	randoms2 := gen_randoms(seed_data, 1000)
 	assert randoms1.len == randoms2.len
diff --git a/vlib/rand/pcg32/pcg32.v b/vlib/rand/pcg32/pcg32.v
index c28c100303..bb7818f501 100644
--- a/vlib/rand/pcg32/pcg32.v
+++ b/vlib/rand/pcg32/pcg32.v
@@ -3,6 +3,7 @@
 // that can be found in the LICENSE file.
 module pcg32
 
+import rand.seed
 import rand.util
 
 // PCG32RNG ported from http://www.pcg-random.org/download.html,
@@ -10,8 +11,8 @@ import rand.util
 // https://github.com/imneme/pcg-c-basic/blob/master/pcg_basic.h
 pub struct PCG32RNG {
 mut:
-	state u64 = u64(0x853c49e6748fea9b) ^ util.time_seed_64()
-	inc   u64 = u64(0xda3e39cb94b95bdb) ^ util.time_seed_64()
+	state u64 = u64(0x853c49e6748fea9b) ^ seed.time_seed_64()
+	inc   u64 = u64(0xda3e39cb94b95bdb) ^ seed.time_seed_64()
 }
 
 // seed seeds the PCG32RNG with 4 `u32` values.
diff --git a/vlib/rand/pcg32/pcg32_test.v b/vlib/rand/pcg32/pcg32_test.v
index 16d41ab8bd..c0a1334d49 100644
--- a/vlib/rand/pcg32/pcg32_test.v
+++ b/vlib/rand/pcg32/pcg32_test.v
@@ -1,6 +1,6 @@
 import math
 import rand.pcg32
-import rand.util
+import rand.seed
 
 const (
 	range_limit = 40
@@ -25,7 +25,7 @@ fn gen_randoms(seed_data []u32, bound int) []u32 {
 }
 
 fn test_pcg32_reproducibility() {
-	seed_data := util.time_seed_array(4)
+	seed_data := seed.time_seed_array(4)
 	randoms1 := gen_randoms(seed_data, 1000)
 	randoms2 := gen_randoms(seed_data, 1000)
 	assert randoms1.len == randoms2.len
diff --git a/vlib/rand/rand.v b/vlib/rand/rand.v
index 774eb84377..d1780c4172 100644
--- a/vlib/rand/rand.v
+++ b/vlib/rand/rand.v
@@ -3,13 +3,13 @@
 // that can be found in the LICENSE file.
 module rand
 
-import rand.util
+import rand.seed
 import rand.wyrand
 import time
 
 // PRNGConfigStruct is a configuration struct for creating a new instance of the default RNG.
 pub struct PRNGConfigStruct {
-	seed []u32 = util.time_seed_array(2)
+	seed []u32 = seed.time_seed_array(2)
 }
 
 __global ( default_rng &wyrand.WyRandRNG )
@@ -141,10 +141,10 @@ pub fn string(len int) string {
 	mut buf := malloc(len)
 	for i in 0 .. len {
 		unsafe {
-			buf[i] = chars[intn(chars.len)]
+			buf[i] = rand.chars[intn(rand.chars.len)]
 		}
 	}
-	return unsafe {buf.vstring_with_len(len)}
+	return unsafe { buf.vstring_with_len(len) }
 }
 
 // uuid_v4 generates a random (v4) UUID
@@ -184,7 +184,7 @@ pub fn uuid_v4() string {
 		buf[14] = `4`
 		buf[buflen] = 0
 	}
-	return unsafe {buf.vstring_with_len(buflen)}
+	return unsafe { buf.vstring_with_len(buflen) }
 }
 
 const (
@@ -209,7 +209,7 @@ pub fn ulid_at_millisecond(unix_time_milli u64) string {
 	mut i := 9
 	for i >= 0 {
 		unsafe {
-			buf[i] = ulid_encoding[t & 0x1F]
+			buf[i] = rand.ulid_encoding[t & 0x1F]
 		}
 		t = t >> 5
 		i--
@@ -219,7 +219,7 @@ pub fn ulid_at_millisecond(unix_time_milli u64) string {
 	i = 10
 	for i < 19 {
 		unsafe {
-			buf[i] = ulid_encoding[x & 0x1F]
+			buf[i] = rand.ulid_encoding[x & 0x1F]
 		}
 		x = x >> 5
 		i++
@@ -228,7 +228,7 @@ pub fn ulid_at_millisecond(unix_time_milli u64) string {
 	x = default_rng.u64()
 	for i < 26 {
 		unsafe {
-			buf[i] = ulid_encoding[x & 0x1F]
+			buf[i] = rand.ulid_encoding[x & 0x1F]
 		}
 		x = x >> 5
 		i++
@@ -236,5 +236,5 @@ pub fn ulid_at_millisecond(unix_time_milli u64) string {
 	unsafe {
 		buf[26] = 0
 	}
-	return unsafe {buf.vstring_with_len(buflen)}
+	return unsafe { buf.vstring_with_len(buflen) }
 }
diff --git a/vlib/rand/random_identifiers_test.v b/vlib/rand/random_identifiers_test.v
index 127c4e3906..290a133398 100644
--- a/vlib/rand/random_identifiers_test.v
+++ b/vlib/rand/random_identifiers_test.v
@@ -40,7 +40,7 @@ fn test_ulids_generated_in_the_same_millisecond_have_the_same_prefix() {
 	t := time.utc().unix_time_milli()
 	mut ulid1 := ''
 	mut ulid2 := ''
-	mut ulid3 := ''    
+	mut ulid3 := ''
 	ulid1 = rand.ulid_at_millisecond(t)
 	ulid2 = rand.ulid_at_millisecond(t)
 	ulid3 = rand.ulid_at_millisecond(t)
diff --git a/vlib/rand/seed/seed.v b/vlib/rand/seed/seed.v
new file mode 100644
index 0000000000..5e9fb76ad2
--- /dev/null
+++ b/vlib/rand/seed/seed.v
@@ -0,0 +1,40 @@
+// Copyright (c) 2019-2021 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 seed
+
+import time
+
+// nr_next returns a next value based on the previous value `prev`.
+[inline]
+fn nr_next(prev u32) u32 {
+	return prev * 1664525 + 1013904223
+}
+
+// time_seed_array returns the required number of u32s generated from system time.
+[inline]
+pub fn time_seed_array(count int) []u32 {
+	ctime := time.now()
+	mut seed := u32(ctime.unix_time() ^ ctime.microsecond)
+	mut seed_data := []u32{cap: count}
+	for _ in 0 .. count {
+		seed = nr_next(seed)
+		seed_data << nr_next(seed)
+	}
+	return seed_data
+}
+
+// time_seed_32 returns a 32-bit seed generated from system time.
+[inline]
+pub fn time_seed_32() u32 {
+	return time_seed_array(1)[0]
+}
+
+// time_seed_64 returns a 64-bit seed generated from system time.
+[inline]
+pub fn time_seed_64() u64 {
+	seed_data := time_seed_array(2)
+	lower := u64(seed_data[0])
+	upper := u64(seed_data[1])
+	return lower | (upper << 32)
+}
diff --git a/vlib/rand/splitmix64/splitmix64.v b/vlib/rand/splitmix64/splitmix64.v
index 01cd076f7f..d1a659ac7f 100644
--- a/vlib/rand/splitmix64/splitmix64.v
+++ b/vlib/rand/splitmix64/splitmix64.v
@@ -3,12 +3,13 @@
 // that can be found in the LICENSE file.
 module splitmix64
 
+import rand.seed
 import rand.util
 
 // SplitMix64RNG ported from http://xoshiro.di.unimi.it/splitmix64.c
 pub struct SplitMix64RNG {
 mut:
-	state     u64 = util.time_seed_64()
+	state     u64 = seed.time_seed_64()
 	has_extra bool
 	extra     u32
 }
diff --git a/vlib/rand/splitmix64/splitmix64_test.v b/vlib/rand/splitmix64/splitmix64_test.v
index 3159e02d06..669da3ccd3 100644
--- a/vlib/rand/splitmix64/splitmix64_test.v
+++ b/vlib/rand/splitmix64/splitmix64_test.v
@@ -1,6 +1,6 @@
 import math
 import rand.splitmix64
-import rand.util
+import rand.seed
 
 const (
 	range_limit = 40
@@ -16,7 +16,7 @@ const (
 
 fn gen_randoms(seed_data []u32, bound int) []u64 {
 	bound_u64 := u64(bound)
-	mut randoms := []u64{len:(20)}
+	mut randoms := []u64{len: (20)}
 	mut rnd := splitmix64.SplitMix64RNG{}
 	rnd.seed(seed_data)
 	for i in 0 .. 20 {
@@ -26,7 +26,7 @@ fn gen_randoms(seed_data []u32, bound int) []u64 {
 }
 
 fn test_splitmix64_reproducibility() {
-	seed_data := util.time_seed_array(2)
+	seed_data := seed.time_seed_array(2)
 	randoms1 := gen_randoms(seed_data, 1000)
 	randoms2 := gen_randoms(seed_data, 1000)
 	assert randoms1.len == randoms2.len
diff --git a/vlib/rand/sys/system_rng.c.v b/vlib/rand/sys/system_rng.c.v
index f8f4507c30..1c426b6764 100644
--- a/vlib/rand/sys/system_rng.c.v
+++ b/vlib/rand/sys/system_rng.c.v
@@ -4,6 +4,7 @@
 module sys
 
 import math.bits
+import rand.seed
 import rand.util
 
 // Implementation note:
@@ -23,8 +24,8 @@ const (
 )
 
 fn calculate_iterations_for(bits int) int {
-	base := bits / rand_bitsize
-	extra := if bits % rand_bitsize == 0 { 0 } else { 1 }
+	base := bits / sys.rand_bitsize
+	extra := if bits % sys.rand_bitsize == 0 { 0 } else { 1 }
 	return base + extra
 }
 
@@ -36,7 +37,7 @@ fn C.rand() int
 // SysRNG is the PRNG provided by default in the libc implementiation that V uses.
 pub struct SysRNG {
 mut:
-	seed u32 = util.time_seed_32()
+	seed u32 = seed.time_seed_32()
 }
 
 // r.seed() sets the seed of the accepting SysRNG to the given data.
@@ -46,7 +47,7 @@ pub fn (mut r SysRNG) seed(seed_data []u32) {
 		exit(1)
 	}
 	r.seed = seed_data[0]
-	unsafe {C.srand(int(r.seed))}
+	unsafe { C.srand(int(r.seed)) }
 }
 
 // r.default_rand() exposes the default behavior of the system's RNG
@@ -63,8 +64,8 @@ pub fn (r SysRNG) default_rand() int {
 [inline]
 pub fn (r SysRNG) u32() u32 {
 	mut result := u32(C.rand())
-	for i in 1 .. u32_iter_count {
-		result = result ^ (u32(C.rand()) << (rand_bitsize * i))
+	for i in 1 .. sys.u32_iter_count {
+		result = result ^ (u32(C.rand()) << (sys.rand_bitsize * i))
 	}
 	return result
 }
@@ -73,8 +74,8 @@ pub fn (r SysRNG) u32() u32 {
 [inline]
 pub fn (r SysRNG) u64() u64 {
 	mut result := u64(C.rand())
-	for i in 1 .. u64_iter_count {
-		result = result ^ (u64(C.rand()) << (rand_bitsize * i))
+	for i in 1 .. sys.u64_iter_count {
+		result = result ^ (u64(C.rand()) << (sys.rand_bitsize * i))
 	}
 	return result
 }
diff --git a/vlib/rand/util/util.v b/vlib/rand/util/util.v
index 9f24c4dca9..b3282fcd44 100644
--- a/vlib/rand/util/util.v
+++ b/vlib/rand/util/util.v
@@ -3,8 +3,6 @@
 // that can be found in the LICENSE file.
 module util
 
-import time
-
 // Commonly used constants across RNGs - some taken from "Numerical Recipes".
 pub const (
 	lower_mask     = u64(0x00000000FFFFFFFF)
@@ -15,37 +13,3 @@ pub const (
 	u31_mask       = u32(0x7FFFFFFF)
 	u63_mask       = u64(0x7FFFFFFFFFFFFFFF)
 )
-
-// nr_next returns a next value based on the previous value `prev`.
-[inline]
-fn nr_next(prev u32) u32 {
-	return prev * 1664525 + 1013904223
-}
-
-// time_seed_array returns the required number of u32s generated from system time.
-[inline]
-pub fn time_seed_array(count int) []u32 {
-	ctime := time.now()
-	mut seed := u32(ctime.unix_time() ^ ctime.microsecond)
-	mut seed_data := []u32{cap: count}
-	for _ in 0 .. count {
-		seed = nr_next(seed)
-		seed_data << nr_next(seed)
-	}
-	return seed_data
-}
-
-// time_seed_32 returns a 32-bit seed generated from system time.
-[inline]
-pub fn time_seed_32() u32 {
-	return time_seed_array(1)[0]
-}
-
-// time_seed_64 returns a 64-bit seed generated from system time.
-[inline]
-pub fn time_seed_64() u64 {
-	seed_data := time_seed_array(2)
-	lower := u64(seed_data[0])
-	upper := u64(seed_data[1])
-	return lower | (upper << 32)
-}
diff --git a/vlib/rand/wyrand/wyrand.v b/vlib/rand/wyrand/wyrand.v
index 253983632f..f052a1e15d 100644
--- a/vlib/rand/wyrand/wyrand.v
+++ b/vlib/rand/wyrand/wyrand.v
@@ -4,8 +4,9 @@
 module wyrand
 
 import math.bits
+import rand.seed
 import rand.util
-import hash as wyhash
+import hash
 
 // Redefinition of some constants that we will need for pseudorandom number generation.
 const (
@@ -16,7 +17,7 @@ const (
 // WyRandRNG is a RNG based on the WyHash hashing algorithm.
 pub struct WyRandRNG {
 mut:
-	state     u64 = util.time_seed_64()
+	state     u64 = seed.time_seed_64()
 	has_extra bool
 	extra     u32
 }
@@ -51,9 +52,9 @@ pub fn (mut rng WyRandRNG) u32() u32 {
 pub fn (mut rng WyRandRNG) u64() u64 {
 	unsafe {
 		mut seed1 := rng.state
-		seed1 += wyp0
+		seed1 += wyrand.wyp0
 		rng.state = seed1
-		return wyhash.wymum(seed1 ^ wyp1, seed1)
+		return hash.wymum(seed1 ^ wyrand.wyp1, seed1)
 	}
 	return 0
 }
diff --git a/vlib/rand/wyrand/wyrand_test.v b/vlib/rand/wyrand/wyrand_test.v
index 86ad8b5ad1..4cdfdb654b 100644
--- a/vlib/rand/wyrand/wyrand_test.v
+++ b/vlib/rand/wyrand/wyrand_test.v
@@ -1,5 +1,5 @@
 import math
-import rand.util
+import rand.seed
 import rand.wyrand
 
 const (
@@ -16,7 +16,7 @@ const (
 
 fn gen_randoms(seed_data []u32, bound int) []u64 {
 	bound_u64 := u64(bound)
-	mut randoms := []u64{len:(20)}
+	mut randoms := []u64{len: (20)}
 	mut rnd := wyrand.WyRandRNG{}
 	rnd.seed(seed_data)
 	for i in 0 .. 20 {
@@ -26,7 +26,7 @@ fn gen_randoms(seed_data []u32, bound int) []u64 {
 }
 
 fn test_wyrand_reproducibility() {
-	seed_data := util.time_seed_array(2)
+	seed_data := seed.time_seed_array(2)
 	randoms1 := gen_randoms(seed_data, 1000)
 	randoms2 := gen_randoms(seed_data, 1000)
 	assert randoms1.len == randoms2.len