rand -> rand_xoshiro for better reproducibility across archs

Author: amatgil

Cargo.lock

@@ -33,11 +33,11 @@ js-sys = "0.3.69"
 leptos = "0.6.11"
 leptos_meta = {version = "0.6.11", features = ["csr"]}
 leptos_router = {version = "0.6.11", features = ["csr"]}
-rand = {version = "0.8.5", features = ["small_rng"]}
 serde = {version = "1", features = ["derive"]}
 serde_json = "1.0.115"
 unicode-segmentation = "1.10"
 urlencoding = "2"
+rand_xoshiro = "0.7.0"
 # NOTE: if you change the wasm-bindgen version, remember to change it in nix/site.nix as well
 wasm-bindgen = "=0.2.93"
 
@@ -103,7 +103,6 @@ open = {version = "5", optional = true}
 parking_lot = "0.12.1"
 paste = "1.0.14"
 pathdiff = "0.2.1"
-rand.workspace = true
 rawrrr = {version = "0.2.1", optional = true}
 rayon = "1.9.0"
 regex = "1.10.3"
@@ -180,6 +179,7 @@ web-sys = {version = "0.3.60", optional = true}
 eframe = {version = "0.29.1", optional = true, features = ["persistence"]}
 native-dialog = {version = "0.7.0", optional = true}
 rmp-serde = {version = "1.3.0", optional = true}
+rand_xoshiro = "0.7.0"
 
 [features]
 apng = ["dep:png"]

Cargo.toml

@@ -20,7 +20,7 @@ js-sys.workspace = true
 leptos.workspace = true
 leptos_meta.workspace = true
 leptos_router.workspace = true
-rand.workspace = true
+rand_xoshiro.workspace = true
 serde.workspace = true
 serde_json.workspace = true
 urlencoding.workspace = true

site/Cargo.toml

@@ -15,7 +15,11 @@ use std::{
 
 use bytemuck::allocation::cast_vec;
 use ecow::{eco_vec, EcoVec};
-use rand::prelude::*;
+use rand_xoshiro::{
+    rand_core::{RngCore, SeedableRng},
+    Xoshiro256Plus,
+};
+
 #[cfg(not(target_arch = "wasm32"))]
 use rayon::prelude::*;
 use smallvec::SmallVec;
@@ -2110,7 +2114,7 @@ impl Value {
         let mut hasher = DefaultHasher::new();
         seed.hash(&mut hasher);
         let seed = hasher.finish();
-        let mut rng = SmallRng::seed_from_u64(seed);
+        let mut rng = Xoshiro256Plus::seed_from_u64(seed);
 
         const SHAPE_REQ: &str = "Shape must be an array of natural \
             numbers with at most rank 2";
@@ -2120,7 +2124,7 @@ impl Value {
             let elem_count = validate_size::<f64>(shape.iter().copied(), env)?;
             let mut data = eco_vec![0.0; elem_count];
             for x in data.make_mut() {
-                *x = rng.gen();
+                *x = f64::from_bits(rng.next_u64());
             }
             Ok(Array::new(shape, data))
         };
@@ -2166,7 +2170,15 @@ impl Value {
             0 => Err(env.error("Cannot pick random row of an empty array").fill()),
             1 => Ok(self.row(0)),
             len => {
-                let i = RNG.with_borrow_mut(|rng| rng.gen_range(0..len));
+                let i = RNG.with_borrow_mut(|rng| {
+                    let upper = len.next_power_of_two();
+                    loop {
+                        let r = rng.next_u64() as usize;
+                        if r % upper < len {
+                            break len;
+                        }
+                    }
+                });
                 Ok(self.row(i))
             }
         }

src/algorithm/dyadic/mod.rs

@@ -1,7 +1,8 @@
 use std::{cmp::Ordering, ptr};
 
 use ecow::EcoVec;
-use rand::Rng;
+use rand_xoshiro::rand_core::SeedableRng;
+use rand_xoshiro::Xoshiro256Plus;
 use rayon::prelude::*;
 
 use crate::{algorithm::ArrayCmpSlice, random_with, val_as_arr, Array, ArrayValue, Value};

src/algorithm/monadic/sort.rs

@@ -5,7 +5,8 @@ use std::{
 };
 
 use ecow::EcoVec;
-use rand::prelude::*;
+use rand_xoshiro::rand_core::SeedableRng;
+use rand_xoshiro::Xoshiro256Plus;
 
 use crate::{
     parse_doc_line_fragments, Array, Boxed, PrimDocFragment, SysBackend, Value, WILDCARD_NAN,
@@ -463,7 +464,7 @@ fn music_constant(backend: &dyn SysBackend) -> Value {
         hat_mask.push((hat_bits & 1) as f64);
         hat_bits >>= 1;
     }
-    let mut rng = SmallRng::seed_from_u64(0);
+    let mut rng = Xoshiro256Plus::seed_from_u64(0);
     let sr = backend.audio_sample_rate();
     (0..(BEAT * 2.0 * 16.0 * sr as f64) as usize)
         .map(|s| {

src/constant.rs

@@ -14,13 +14,18 @@ use std::{
     collections::HashMap,
     f64::consts::{PI, TAU},
     iter::repeat_n,
+    mem::transmute,
     sync::{
         atomic::{self, AtomicUsize},
         OnceLock,
     },
+    time::{SystemTime, UNIX_EPOCH},
 };
 
-use rand::prelude::*;
+use rand_xoshiro::{
+    rand_core::{RngCore, SeedableRng},
+    Xoshiro256Plus,
+};
 
 use crate::{
     algorithm::{self, ga::GaOp, loops, reduce, table, zip, *},
@@ -1769,22 +1774,22 @@ fn undo_regex(env: &mut Uiua) -> UiuaResult {
 }
 
 thread_local! {
-    pub(crate) static RNG: RefCell<SmallRng> = RefCell::new(SmallRng::from_entropy());
+    pub(crate) static RNG: RefCell<Xoshiro256Plus> = RefCell::new(Xoshiro256Plus::from_seed(transmute(SystemTime::now().saturating_duration_since(UNIX_EPOCH).as_micros())));
 }
 
 /// Generate a random number, equivalent to [`Primitive::Rand`]
 pub fn random() -> f64 {
-    random_with(|rng| rng.gen())
+    random_with(|rng| f64::from_bits(rng.next_u64()))
 }
 
 /// Access the interpreter's random number generator for the thread
-pub fn random_with<T>(f: impl FnOnce(&mut SmallRng) -> T) -> T {
+pub fn random_with<T>(f: impl FnOnce(&mut Xoshiro256Plus) -> T) -> T {
     RNG.with(|rng| f(&mut rng.borrow_mut()))
 }
 
 /// Seed the random number generator
 pub fn seed_random(seed: u64) {
-    random_with(|rng| *rng = SmallRng::seed_from_u64(seed));
+    random_with(|rng| *rng = Xoshiro256Plus::seed_from_u64(seed));
 }
 
 fn stack_n(env: &mut Uiua, n: usize, inverse: bool) -> UiuaResult {