Drop aHash dependency in favor of hashbrown's choice of default hasher

Cargo.toml

@@ -20,8 +20,7 @@ maintenance = { status = "actively-developed" }
 
 
 [dependencies]
-ahash = "0.8.0"
-hashbrown = { version = "0.15", default-features = false, features = ["inline-more"] }
+hashbrown = { version = "0.15", default-features = false, features = ["default-hasher", "inline-more"] }
 
 [features]
 default = ["unified_diff"]

src/intern.rs

@@ -1,8 +1,8 @@
-use std::hash::Hash;
+use std::hash::{BuildHasher as _, Hash, Hasher as _};
 use std::ops::Index;
 
-use ahash::RandomState;
 use hashbrown::hash_table::{Entry, HashTable};
+use hashbrown::DefaultHashBuilder as RandomState;
 
 /// A token represented as an interned integer.
 ///
@@ -114,7 +114,7 @@ impl<T: Hash + Eq> Interner<T> {
         Interner {
             tokens: Vec::with_capacity(capacity),
             table: HashTable::with_capacity(capacity),
-            hasher: RandomState::new(),
+            hasher: RandomState::default(),
         }
     }
 
@@ -126,11 +126,11 @@ impl<T: Hash + Eq> Interner<T> {
 
     /// Intern `token` and return a the interned integer
     pub fn intern(&mut self, token: T) -> Token {
-        let hash = self.hasher.hash_one(&token);
+        let hash = hash_one(&self.hasher, &token);
         match self.table.entry(
             hash,
             |&it| self.tokens[it.0 as usize] == token,
-            |&token| self.hasher.hash_one(&self.tokens[token.0 as usize]),
+            |&token| hash_one(&self.hasher, &self.tokens[token.0 as usize]),
         ) {
             Entry::Occupied(entry) => *entry.get(),
             Entry::Vacant(entry) => {
@@ -155,14 +155,14 @@ impl<T: Hash + Eq> Interner<T> {
         if retained <= erased {
             self.table.clear();
             for (i, token) in self.tokens[0..retained].iter().enumerate() {
-                let hash = self.hasher.hash_one(token);
+                let hash = hash_one(&self.hasher, &token);
                 self.table.insert_unique(hash, Token(i as u32), |&token| {
-                    self.hasher.hash_one(&self.tokens[token.0 as usize])
+                    hash_one(&self.hasher, &self.tokens[token.0 as usize])
                 });
             }
         } else {
             for (i, token) in self.tokens[retained..].iter().enumerate() {
-                let hash = self.hasher.hash_one(token);
+                let hash = hash_one(&self.hasher, &token);
                 match self
                     .table
                     .find_entry(hash, |token| token.0 == (retained + i) as u32)
@@ -182,3 +182,12 @@ impl<T: Hash + Eq> Index<Token> for Interner<T> {
         &self.tokens[index.0 as usize]
     }
 }
+
+// TODO: remove in favor of BuildHasher::hash_one once compilers older than 1.71
+// no longer need to be supported.
+// https://doc.rust-lang.org/std/hash/trait.BuildHasher.html#method.hash_one
+fn hash_one<T: Hash>(hasher_parameters: &RandomState, token: &T) -> u64 {
+    let mut hasher = hasher_parameters.build_hasher();
+    token.hash(&mut hasher);
+    hasher.finish()
+}