assignment is defined over base field

Author: kunxian-xia

spartan_parallel/Cargo.toml

@@ -30,6 +30,7 @@ colored = { version = "2", default-features = false, optional = true }
 flate2 = { version = "1" }
 goldilocks = { git = "https://github.com/scroll-tech/ceno-Goldilocks" }
 ff = "0.13.0"
+halo2curves = "0.1.0"
 
 [dev-dependencies]
 criterion = "0.5"

spartan_parallel/src/lib.rs

@@ -46,6 +46,7 @@ use std::{
 
 use dense_mlpoly::{DensePolynomial, PolyEvalProof};
 use errors::{ProofVerifyError, R1CSError};
+use halo2curves::serde::SerdeObject;
 use instance::Instance;
 use itertools::Itertools;
 use math::Math;
@@ -79,34 +80,21 @@ pub struct ComputationDecommitment<S: SpartanExtensionField> {
 #[derive(Clone, Serialize, Deserialize)]
 pub struct Assignment<S: SpartanExtensionField> {
   /// Entries of an assignment
-  pub assignment: Vec<S>,
+  pub assignment: Vec<S::BaseField>,
 }
 
 impl<S: SpartanExtensionField> Assignment<S> {
   /// Constructs a new `Assignment` from a vector
   pub fn new(assignment: &[[u8; 32]]) -> Result<Assignment<S>, R1CSError> {
-    let bytes_to_scalar = |vec: &[[u8; 32]]| -> Result<Vec<S>, R1CSError> {
-      let mut vec_scalar: Vec<S> = Vec::new();
-      for v in vec {
-        let val = S::from_bytes(v);
-        if val.is_some().unwrap_u8() == 1 {
-          vec_scalar.push(val.unwrap());
-        } else {
-          return Err(R1CSError::InvalidScalar);
-        }
-      }
-      Ok(vec_scalar)
+    let bytes_to_scalar = |vec: &[[u8; 32]]| -> Result<Vec<S::BaseField>, R1CSError> {
+      vec
+        .into_iter()
+        .map(|v| S::BaseField::from_raw_bytes(v).ok_or(R1CSError::InvalidScalar))
+        .collect()
     };
     let assignment_scalar = bytes_to_scalar(assignment);
 
-    // check for any parsing errors
-    if assignment_scalar.is_err() {
-      return Err(R1CSError::InvalidScalar);
-    }
-
-    Ok(Assignment {
-      assignment: assignment_scalar.unwrap(),
-    })
+    assignment_scalar.map(|a| Assignment { assignment: a })
   }
 
   /// Write the assignment into a file

spartan_parallel/src/scalar/mod.rs

@@ -4,10 +4,10 @@ mod fp2;
 use ff::Field;
 pub use fp::Scalar;
 pub use fp2::ScalarExt2;
-use goldilocks::ExtensionField;
+use goldilocks::{ExtensionField, SmallField};
 use merlin::Transcript;
 use rand::{CryptoRng, RngCore};
-use serde::Serialize;
+use serde::{Deserialize, Serialize};
 use std::fmt;
 use std::{
   cmp::Eq,
@@ -49,7 +49,7 @@ pub trait SpartanExtensionField:
   type InnerType: ExtensionField + Field;
 
   /// Basefield for conserving computational resources
-  type BaseField: Field;
+  type BaseField: SmallField + for<'a> Deserialize<'a>;
 
   /// Return inner Goldilocks field element
   fn inner(&self) -> &Self::InnerType;