Add interaction_element_ids to Component trait.

crates/prover/src/core/air/air_ext.rs

@@ -1,17 +1,19 @@
+use std::collections::BTreeSet;
 use std::iter::zip;
 
-use itertools::Itertools;
+use itertools::{zip_eq, Itertools};
 
 use super::accumulation::{DomainEvaluationAccumulator, PointEvaluationAccumulator};
 use super::{Air, AirProver, ComponentTrace};
 use crate::core::backend::Backend;
+use crate::core::channel::{Blake2sChannel, Channel};
 use crate::core::circle::CirclePoint;
 use crate::core::fields::m31::BaseField;
 use crate::core::fields::qm31::SecureField;
 use crate::core::poly::circle::{CanonicCoset, CircleEvaluation, CirclePoly, SecureCirclePoly};
 use crate::core::poly::BitReversedOrder;
 use crate::core::prover::LOG_BLOWUP_FACTOR;
-use crate::core::ComponentVec;
+use crate::core::{ComponentVec, InteractionElements};
 
 pub trait AirExt: Air {
     fn composition_log_degree_bound(&self) -> u32 {
@@ -41,6 +43,15 @@ pub trait AirExt: Air {
         component_points
     }
 
+    fn interaction_elements(&self, channel: &mut Blake2sChannel) -> InteractionElements {
+        let mut ids = BTreeSet::new();
+        for component in self.components() {
+            ids.extend(component.interaction_element_ids());
+        }
+        let elements = channel.draw_felts(ids.len()).into_iter().map(|e| e.0 .0);
+        InteractionElements(zip_eq(ids, elements).collect_vec())
+    }
+
     fn eval_composition_polynomial_at_point(
         &self,
         point: CirclePoint<SecureField>,

crates/prover/src/core/air/mod.rs

@@ -41,6 +41,9 @@ pub trait Component {
         point: CirclePoint<SecureField>,
     ) -> ColumnVec<Vec<CirclePoint<SecureField>>>;
 
+    /// Returns the ids of the interaction elements used by the component.
+    fn interaction_element_ids(&self) -> Vec<String>;
+
     /// Evaluates the constraint quotients combination of the component, given the mask values.
     fn evaluate_constraint_quotients_at_point(
         &self,

crates/prover/src/core/mod.rs

@@ -1,5 +1,7 @@
 use std::ops::{Deref, DerefMut};
 
+use self::fields::m31::BaseField;
+
 pub mod air;
 pub mod backend;
 pub mod channel;
@@ -57,3 +59,5 @@ impl<T> DerefMut for ComponentVec<T> {
         &mut self.0
     }
 }
+
+pub struct InteractionElements(Vec<(String, BaseField)>);

crates/prover/src/core/prover/mod.rs

@@ -321,6 +321,10 @@ mod tests {
             vec![vec![point]]
         }
 
+        fn interaction_element_ids(&self) -> Vec<String> {
+            vec![]
+        }
+
         fn evaluate_constraint_quotients_at_point(
             &self,
             _point: CirclePoint<SecureField>,

crates/prover/src/examples/fibonacci/component.rs

@@ -94,6 +94,10 @@ impl Component for FibonacciComponent {
         )
     }
 
+    fn interaction_element_ids(&self) -> Vec<String> {
+        vec![]
+    }
+
     fn evaluate_constraint_quotients_at_point(
         &self,
         point: CirclePoint<SecureField>,

crates/prover/src/examples/wide_fibonacci/component.rs

@@ -67,6 +67,13 @@ impl Component for WideFibComponent {
         fixed_mask_points(&vec![vec![0_usize]; self.n_columns()], point)
     }
 
+    fn interaction_element_ids(&self) -> Vec<String> {
+        vec![
+            "wide_fibonacci_alpha".to_string(),
+            "wide_fibonacci_z".to_string(),
+        ]
+    }
+
     fn evaluate_constraint_quotients_at_point(
         &self,
         point: CirclePoint<SecureField>,