Merge pull request #2629 from o1-labs/dw/move-inner-prod-field-helpers

Poly_commitment/utils: move inner_prod into field_helpers

poly-commitment/src/commitment.rs

@@ -608,14 +608,6 @@ pub fn combine_evaluations<G: CommitmentCurve>(
     acc
 }
 
-pub fn inner_prod<F: Field>(xs: &[F], ys: &[F]) -> F {
-    let mut res = F::zero();
-    for (&x, y) in xs.iter().zip(ys) {
-        res += &(x * y);
-    }
-    res
-}
-
 #[cfg(feature = "ocaml_types")]
 pub mod caml {
     // polynomial commitment

poly-commitment/src/srs.rs

@@ -3,9 +3,8 @@
 
 use crate::{
     commitment::{
-        b_poly, b_poly_coefficients, combine_commitments, inner_prod, shift_scalar,
-        squeeze_prechallenge, BatchEvaluationProof, BlindedCommitment, CommitmentCurve, EndoCurve,
-        Evaluation,
+        b_poly, b_poly_coefficients, combine_commitments, shift_scalar, squeeze_prechallenge,
+        BatchEvaluationProof, BlindedCommitment, CommitmentCurve, EndoCurve, Evaluation,
     },
     error::CommitmentError,
     evaluation_proof::{combine_polys, Challenges, OpeningProof},
@@ -20,7 +19,10 @@ use ark_serialize::{CanonicalDeserialize, CanonicalSerialize};
 use blake2::{Blake2b512, Digest};
 use groupmap::GroupMap;
 use mina_poseidon::{sponge::ScalarChallenge, FqSponge};
-use o1_utils::{field_helpers::pows, math, ExtendedDensePolynomial};
+use o1_utils::{
+    field_helpers::{inner_prod, pows},
+    math, ExtendedDensePolynomial,
+};
 use rand::{CryptoRng, RngCore};
 use rayon::prelude::*;
 use serde::{Deserialize, Serialize};

utils/src/field_helpers.rs

@@ -229,3 +229,12 @@ pub fn product<F: Field>(xs: impl Iterator<Item = F>) -> F {
     }
     res
 }
+
+/// COmpute the inner product of two slices of field elements.
+pub fn inner_prod<F: Field>(xs: &[F], ys: &[F]) -> F {
+    let mut res = F::zero();
+    for (&x, y) in xs.iter().zip(ys) {
+        res += &(x * y);
+    }
+    res
+}