fix: support more weird relations.

Author: mmaker

src/linear_relation/ops.rs

@@ -246,6 +246,21 @@ mod add {
         }
     }
 
+    impl<G: Group> Add<Sum<Weighted<Term<G>, G::Scalar>>> for Weighted<GroupVar<G>, G::Scalar> {
+        type Output = Sum<Weighted<Term<G>, G::Scalar>>;
+
+        fn add(self, rhs: Sum<Weighted<Term<G>, G::Scalar>>) -> Self::Output {
+            let weighted_term = Weighted {
+                term: Term {
+                    scalar: super::ScalarTerm::Unit,
+                    elem: self.term,
+                },
+                weight: self.weight,
+            };
+            rhs + weighted_term
+        }
+    }
+
     impl<G: Group> Add<Weighted<GroupVar<G>, G::Scalar>> for Sum<Weighted<Term<G>, G::Scalar>> {
         type Output = Sum<Weighted<Term<G>, G::Scalar>>;
 

src/tests/test_relations.rs

@@ -371,23 +371,21 @@ fn cmz_wallet_spend_relation<G: PrimeGroup, R: RngCore>(
 }
 
 
-fn test_another_relation<G: PrimeGroup, R: RngCore>(
+fn nested_affine_relation<G: PrimeGroup, R: RngCore>(
     mut rng: &mut R,
 ) -> (CanonicalLinearRelation<G>, Vec<G::Scalar>) {
     let mut instance = LinearRelation::<G>::new();
-    let r = instance.allocate_scalar();
+    let var_r = instance.allocate_scalar();
     let var_A = instance.allocate_element();
     let var_B = instance.allocate_element();
     let eq1 = instance.allocate_eq(
-        var_A * G::Scalar::from(4)
-            + (r * G::Scalar::from(2) + G::Scalar::from(3)) * var_B,
+        var_A * G::Scalar::from(4) + (var_r * G::Scalar::from(2) + G::Scalar::from(3)) * var_B,
     );
 
     let A = G::random(&mut rng);
     let B = G::random(&mut rng);
     let r = G::Scalar::random(&mut rng);
-    let C = A * G::Scalar::from(4)
-            + (r * G::Scalar::from(2) + G::Scalar::from(3)) * var_B;
+    let C = A * G::Scalar::from(4) + B * (r * G::Scalar::from(2) + G::Scalar::from(3));
     instance.set_element(var_A, A);
     instance.set_element(var_B, B);
     instance.set_element(eq1, C);
@@ -478,6 +476,7 @@ fn test_relations() {
             "cmz_wallet_spend_relation",
             Box::new(cmz_wallet_spend_relation),
         ),
+        ("nested_affine_relation", Box::new(nested_affine_relation)),
     ];
 
     for (relation_name, relation_sampler) in instance_generators.iter() {