Set MSRV 1.85 & use stable toolchain

dusk-merkle/Cargo.toml

@@ -12,6 +12,7 @@ authors = [
 ]
 
 edition = "2021"
+rust-version = "1.85"
 license = "MPL-2.0"
 
 [dependencies]

dusk-merkle/README.md

@@ -90,8 +90,6 @@ For the opening proof creation in zero-knowledge:
 cargo bench -p poseidon-merkle --features zk
 ```
 
-This requires a nightly toolchain.
-
 ## Implementations
 
 A merkle tree using the poseidon hash function for aggregation and plonk to

dusk-merkle/src/node.rs

@@ -32,7 +32,7 @@ where
         }
     }
 
-    pub(crate) fn item(&self) -> Ref<T> {
+    pub(crate) fn item(&self) -> Ref<'_, T> {
         // a leaf will always have a computed item, so we never go into it
         if self.item.borrow().is_none() {
             // compute our item, recursing into the children.

dusk-merkle/src/tree.rs

@@ -91,20 +91,20 @@ where
     /// the output of the walker function. The function should return `true` or
     /// `false`, indicating whether the iterator should continue along the
     /// tree's path.
-    pub fn walk<W>(&self, walker: W) -> Walk<T, W, H, A>
+    pub fn walk<W>(&self, walker: W) -> Walk<'_, T, W, H, A>
     where
         W: Fn(&T) -> bool,
     {
         Walk::new(self, walker)
     }
 
     /// Get the root of the merkle tree.
-    pub fn root(&self) -> Ref<T> {
+    pub fn root(&self) -> Ref<'_, T> {
         self.root.item()
     }
 
     /// Returns the root of the smallest sub-tree that holds all the leaves.
-    pub fn smallest_subtree(&self) -> (Ref<T>, usize) {
+    pub fn smallest_subtree(&self) -> (Ref<'_, T>, usize) {
         let mut smallest_node = &self.root;
         let mut height = H;
         loop {

dusk-merkle/src/walk.rs

@@ -96,9 +96,8 @@ where
                     let child = child.as_ref();
                     if (self.walker)(&*child.item()) {
                         self.path[h] = Some(child);
-                        match self.advance(child, h + 1) {
-                            Some(item) => return Some(item),
-                            None => continue,
+                        if let Some(item) = self.advance(child, h + 1) {
+                            return Some(item);
                         }
                     }
                 }

poseidon-merkle/Cargo.toml

@@ -12,14 +12,15 @@ authors = [
 ]
 
 edition = "2021"
+rust-version = "1.85"
 license = "MPL-2.0"
 
 [dependencies]
 dusk-bytes = "0.1"
 dusk-merkle = "0.5"
-dusk-poseidon = "0.41"
+dusk-poseidon = "0.42.0-rc.0"
 dusk-bls12_381 = { version = "0.14", default-features = false }
-dusk-plonk = { version = "0.21", optional = true, default-features = false }
+dusk-plonk = { version = "0.22.0-rc.0", optional = true, default-features = false }
 rkyv = { version = "0.7", optional = true, default-features = false }
 bytecheck = { version = "0.6", optional = true, default-features = false }
 

poseidon-merkle/benches/poseidon.rs

@@ -7,16 +7,14 @@
 use criterion::{black_box, criterion_group, criterion_main, Criterion};
 
 use dusk_bls12_381::BlsScalar;
-use dusk_poseidon::sponge::hash as poseidon_hash;
+use dusk_poseidon::{Domain, Hash};
 use poseidon_merkle::{Item, Tree};
 
 use rand::{RngCore, SeedableRng};
 
-// set height and arity of the poseidon merkle tree
 const HEIGHT: usize = 17;
-const ARITY: usize = 4;
 
-type PoseidonTree = Tree<(), HEIGHT, ARITY>;
+type PoseidonTree = Tree<(), HEIGHT>;
 type PoseidonItem = Item<()>;
 
 fn bench_poseidon(c: &mut Criterion) {
@@ -26,7 +24,14 @@ fn bench_poseidon(c: &mut Criterion) {
     c.bench_function("poseidon insertion", |b| {
         b.iter(|| {
             let pos = rng.next_u64() % u32::MAX as u64;
-            let hash = poseidon_hash(&[BlsScalar::from(pos)]);
+
+            let hash = Hash::digest(Domain::Other, &[BlsScalar::from(pos)])
+                .into_iter()
+                .next()
+                .expect(
+                    "Poseidon hash output must contain at least one element",
+                );
+
             let item = PoseidonItem { hash, data: () };
             tree.insert(black_box(pos), black_box(item));
         })

rust-toolchain.toml

@@ -1,3 +1,3 @@
 [toolchain]
-channel = "nightly-2023-11-10"
+channel = "stable"
 components = ["rustfmt", "clippy"]

rustfmt.toml

@@ -1,2 +1 @@
-wrap_comments = true
 max_width = 80