Revert "refactor: Refactor R1CS for in-place operations and Vec inputs (

argumentcomputer#121)" (argumentcomputer#125)

This reverts commit fdf8296.

This should allow us to investigate the effects of components of argumentcomputer#118 without noise.
We can re-apply this later if we see it as an improvement.

Cargo.toml

@@ -42,7 +42,6 @@ tracing-texray = "0.2.0"
 tracing-subscriber = { version = "0.3.17", features = ["env-filter"] }
 cfg-if = "1.0.0"
 once_cell = "1.18.0"
-vecshard = "0.2.1"
 
 [target.'cfg(any(target_arch = "x86_64", target_arch = "aarch64"))'.dependencies]
 pasta-msm = { git="https://github.com/lurk-lab/pasta-msm", branch="dev", version = "0.1.4" }

src/bellpepper/r1cs.rs

@@ -11,13 +11,12 @@ use crate::{
 };
 use bellpepper_core::{Index, LinearCombination};
 use ff::PrimeField;
-use vecshard::ShardExt;
 
 /// `NovaWitness` provide a method for acquiring an `R1CSInstance` and `R1CSWitness` from implementers.
 pub trait NovaWitness<G: Group> {
   /// Return an instance and witness, given a shape and ck.
   fn r1cs_instance_and_witness(
-    self,
+    &self,
     shape: &R1CSShape<G>,
     ck: &CommitmentKey<G>,
   ) -> Result<(R1CSInstance<G>, R1CSWitness<G>), NovaError>;
@@ -40,19 +39,16 @@ pub trait NovaShape<G: Group> {
 
 impl<G: Group> NovaWitness<G> for SatisfyingAssignment<G> {
   fn r1cs_instance_and_witness(
-    self,
+    &self,
     shape: &R1CSShape<G>,
     ck: &CommitmentKey<G>,
   ) -> Result<(R1CSInstance<G>, R1CSWitness<G>), NovaError> {
-    let (input_assignment, aux_assignment) = self.to_assignments();
-
-    let W = R1CSWitness::<G>::new(shape, aux_assignment)?;
-
-    let (_, X) = input_assignment.split_inplace_at(1);
+    let W = R1CSWitness::<G>::new(shape, self.aux_assignment())?;
+    let X = &self.input_assignment()[1..];
 
     let comm_W = W.commit(ck);
 
-    let instance = R1CSInstance::<G>::new(shape, &comm_W, X.into())?;
+    let instance = R1CSInstance::<G>::new(shape, &comm_W, X)?;
 
     Ok((instance, W))
   }

src/nifs.rs

@@ -356,13 +356,13 @@ mod tests {
         };
 
         let W = {
-          let res = R1CSWitness::new(&S, vars);
+          let res = R1CSWitness::new(&S, &vars);
           assert!(res.is_ok());
           res.unwrap()
         };
         let U = {
           let comm_W = W.commit(ck);
-          let res = R1CSInstance::new(&S, &comm_W, X);
+          let res = R1CSInstance::new(&S, &comm_W, &X);
           assert!(res.is_ok());
           res.unwrap()
         };

src/r1cs/mod.rs

@@ -386,11 +386,11 @@ impl<G: Group> R1CSShape<G> {
 
 impl<G: Group> R1CSWitness<G> {
   /// A method to create a witness object using a vector of scalars
-  pub fn new(S: &R1CSShape<G>, W: Vec<G::Scalar>) -> Result<R1CSWitness<G>, NovaError> {
+  pub fn new(S: &R1CSShape<G>, W: &[G::Scalar]) -> Result<R1CSWitness<G>, NovaError> {
     if S.num_vars != W.len() {
       Err(NovaError::InvalidWitnessLength)
     } else {
-      Ok(R1CSWitness { W })
+      Ok(R1CSWitness { W: W.to_owned() })
     }
   }
 
@@ -405,12 +405,15 @@ impl<G: Group> R1CSInstance<G> {
   pub fn new(
     S: &R1CSShape<G>,
     comm_W: &Commitment<G>,
-    X: Vec<G::Scalar>,
+    X: &[G::Scalar],
   ) -> Result<R1CSInstance<G>, NovaError> {
     if S.num_io != X.len() {
       Err(NovaError::InvalidInputLength)
     } else {
-      Ok(R1CSInstance { comm_W: *comm_W, X })
+      Ok(R1CSInstance {
+        comm_W: *comm_W,
+        X: X.to_owned(),
+      })
     }
   }
 }