dynamic node discriminant computation

Author: addisoncrump

Cargo.lock

@@ -64,6 +64,7 @@ anyhow = { version = "1.0", default-features = false }
 criterion = { version = "0.7.0", features = ["html_reports"] }
 either = { version = "1.13", default-features = false }
 embedded-io = { version = "0.6.1", features = ["alloc"] }
+foldhash = { version = "0.2.0", default-features = false }
 hashbrown = "0.16.0"
 linfa = "0.7.1"
 linfa-linear = "0.7.1"

Cargo.toml

@@ -8,7 +8,7 @@ use fandango::dynamic::{DynamicNode, DynamicSampler};
 use fandango::generation::{Generated, InPlaceGenerated};
 use fandango::lang::FandangoNode;
 use fandango::tuple_list::{tuple_list, tuple_list_type};
-use fandango::typing::{AsNodeRef, AsStaticNode, Discriminable, Node, Opaque};
+use fandango::typing::{AsNode, AsNodeRef, AsStaticNode, Discriminable, Node, Opaque};
 use fandango::visitor::assignment::SwapVisitor;
 use fandango::visitor::navigation::{Advance, CountNodes, GoTo, GoToMut};
 use fandango::visitor::{VisitResult, VisitWith, VisitWithMut, VisitableChildren, Visitor};
@@ -333,27 +333,25 @@ where
             let (time, _) = measure(
                 (generated.clone(), local_sampler.clone()),
                 |(mutated, sampler)| {
-                    black_box(mutated)
-                        .go_to_mut(idx, black_box(path))
-                        .unwrap()
-                        .generate_in_place(
-                            &mut DynamicSampler::new(
-                                <B::Start as AsStaticNode>::static_root(),
-                                <B::Start as AsStaticNode>::static_definition(),
-                                &nonterminals,
-                                black_box(sampler),
-                            ),
-                            &mut generator,
-                            path.len(),
-                        );
+                    let selected = black_box(mutated).go_to_mut(idx, black_box(path)).unwrap();
+                    selected.generate_in_place(
+                        &mut DynamicSampler::new(
+                            <B::Start as AsStaticNode>::static_root(),
+                            selected.definition(),
+                            &nonterminals,
+                            black_box(sampler),
+                        ),
+                        &mut generator,
+                        path.len(),
+                    );
                 },
             );
             let mut cloned = generated.clone();
             let mutated = cloned.go_to_mut(idx, path).unwrap();
             mutated.generate_in_place(
                 &mut DynamicSampler::new(
                     <B::Start as AsStaticNode>::static_root(),
-                    <B::Start as AsStaticNode>::static_definition(),
+                    mutated.definition(),
                     &nonterminals,
                     &mut local_sampler,
                 ),

baselines/benches/models.rs

@@ -7,10 +7,9 @@ authors.workspace = true
 [dependencies]
 either = { workspace = true }
 embedded-io.workspace = true
+foldhash.workspace = true
 hashbrown = { workspace = true, features = ["serde"] }
 mappable-rc.workspace = true
-num-integer.workspace = true
-num-traits.workspace = true
 pest.workspace = true
 pest_derive.workspace = true
 petgraph = { workspace = true, features = ["graphmap"] }

core/Cargo.toml

@@ -20,7 +20,8 @@ use alloc::vec;
 use alloc::vec::Vec;
 use core::hash::BuildHasher;
 use core::ops::ControlFlow;
-use hashbrown::{DefaultHashBuilder, HashMap};
+use foldhash::fast::SeedableRandomState;
+use hashbrown::HashMap;
 
 type FandangoNode = crate::lang::FandangoNode<'static, 'static>;
 
@@ -433,13 +434,13 @@ impl AssignFrom<&'_ DynamicNode> for &'_ mut DynamicNode {
 
 impl DiscriminantLookup for &'_ DynamicNode {
     fn lookup_discriminant(node: &crate::lang::FandangoNode) -> usize {
-        DefaultHashBuilder::default().hash_one(node) as usize
+        SeedableRandomState::fixed().hash_one(node) as usize
     }
 }
 
 impl DiscriminantLookup for &'_ mut DynamicNode {
     fn lookup_discriminant(node: &crate::lang::FandangoNode) -> usize {
-        DefaultHashBuilder::default().hash_one(node) as usize
+        SeedableRandomState::fixed().hash_one(node) as usize
     }
 }