From cff86c045d92e68fac89dbc5e9ac295c31c58724 Mon Sep 17 00:00:00 2001
From: Michael Rosenberg <michael@mrosenberg.pub>
Date: Fri, 18 Mar 2022 03:59:39 -0400
Subject: [PATCH 1/4] impl'd EqGadget, CondSelectGadget, R1CSVar for Vec<T>

---
 src/eq.rs     | 28 ++++++++++++++++++++++++++++
 src/lib.rs    | 13 +++++++++++++
 src/select.rs | 19 +++++++++++++++++++
 3 files changed, 60 insertions(+)

diff --git a/src/eq.rs b/src/eq.rs
index f1184619..d104032d 100644
--- a/src/eq.rs
+++ b/src/eq.rs
@@ -128,3 +128,31 @@ impl<T: EqGadget<F> + R1CSVar<F>, F: Field> EqGadget<F> for [T] {
         }
     }
 }
+
+// EqGadget for Vec<T> just calls down to EqGadget for [T]
+impl<T: EqGadget<F> + R1CSVar<F>, F: Field> EqGadget<F> for Vec<T> {
+    #[tracing::instrument(target = "r1cs", skip(self, other))]
+    fn is_eq(&self, other: &Self) -> Result<Boolean<F>, SynthesisError> {
+        self.as_slice().is_eq(other.as_slice())
+    }
+
+    #[tracing::instrument(target = "r1cs", skip(self, other))]
+    fn conditional_enforce_equal(
+        &self,
+        other: &Self,
+        condition: &Boolean<F>,
+    ) -> Result<(), SynthesisError> {
+        self.as_slice()
+            .conditional_enforce_equal(other.as_slice(), condition)
+    }
+
+    #[tracing::instrument(target = "r1cs", skip(self, other))]
+    fn conditional_enforce_not_equal(
+        &self,
+        other: &Self,
+        should_enforce: &Boolean<F>,
+    ) -> Result<(), SynthesisError> {
+        self.as_slice()
+            .conditional_enforce_not_equal(other.as_slice(), should_enforce)
+    }
+}
diff --git a/src/lib.rs b/src/lib.rs
index 8ff44b0d..20cea7ce 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -124,6 +124,19 @@ impl<'a, F: Field, T: 'a + R1CSVar<F>> R1CSVar<F> for &'a T {
     }
 }
 
+// R1CSVar for Vec<T> just calls down to R1CSVar for [T]
+impl<F: Field, T: R1CSVar<F>> R1CSVar<F> for Vec<T> {
+    type Value = Vec<T::Value>;
+
+    fn cs(&self) -> ark_relations::r1cs::ConstraintSystemRef<F> {
+        self.as_slice().cs()
+    }
+
+    fn value(&self) -> Result<Self::Value, ark_relations::r1cs::SynthesisError> {
+        self.as_slice().value()
+    }
+}
+
 /// A utility trait to convert `Self` to `Result<T, SynthesisErrorA`.>
 pub trait Assignment<T> {
     /// Converts `self` to `Result`.
diff --git a/src/select.rs b/src/select.rs
index bbc2c3c9..4d538236 100644
--- a/src/select.rs
+++ b/src/select.rs
@@ -115,3 +115,22 @@ where
         constants: &[Self::TableConstant],
     ) -> Result<Self, SynthesisError>;
 }
+
+impl<ConstraintF, T> CondSelectGadget<ConstraintF> for Vec<T>
+where
+    ConstraintF: Field,
+    T: CondSelectGadget<ConstraintF>,
+{
+    #[tracing::instrument(target = "r1cs", skip(true_value, false_value))]
+    fn conditionally_select(
+        cond: &Boolean<ConstraintF>,
+        true_value: &Vec<T>,
+        false_value: &Vec<T>,
+    ) -> Result<Vec<T>, SynthesisError> {
+        true_value
+            .iter()
+            .zip(false_value.iter())
+            .map(|(t, f)| T::conditionally_select(cond, t, f))
+            .collect()
+    }
+}

From 84a112fafdf9e13d0dce11706a374e38e3aa20f1 Mon Sep 17 00:00:00 2001
From: Michael Rosenberg <michael@mrosenberg.pub>
Date: Fri, 18 Mar 2022 04:05:51 -0400
Subject: [PATCH 2/4] Added length assertion to ConSelectGadget for Vec<T>

---
 src/select.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/select.rs b/src/select.rs
index 4d538236..6fafcb9d 100644
--- a/src/select.rs
+++ b/src/select.rs
@@ -127,6 +127,8 @@ where
         true_value: &Vec<T>,
         false_value: &Vec<T>,
     ) -> Result<Vec<T>, SynthesisError> {
+        assert_eq!(true_value.len(), false_value.len());
+
         true_value
             .iter()
             .zip(false_value.iter())

From 7054f77a25ce00d9f76a7d2c9a464ddccf2ea285 Mon Sep 17 00:00:00 2001
From: Michael Rosenberg <michael@mrosenberg.pub>
Date: Fri, 18 Mar 2022 04:06:10 -0400
Subject: [PATCH 3/4] Updated changelog

---
 CHANGELOG.md | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0b412830..81db8c33 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,8 @@
 
 ## Pending
 
+* Implement `EqGadget`, `CondSelectGadget`, and `R1CSVar` for `Vec<T>`
+
 ### Breaking changes
 
 - [\#86](https://github.com/arkworks-rs/r1cs-std/pull/86) Change the API for domains for coset.

From b6af7edec708c45f3bc6d0e64598299406ac4f16 Mon Sep 17 00:00:00 2001
From: Michael Rosenberg <michael@mrosenberg.pub>
Date: Fri, 18 Mar 2022 04:07:45 -0400
Subject: [PATCH 4/4] Added PR link to changelog

---
 CHANGELOG.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 81db8c33..be1c325d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,7 +2,7 @@
 
 ## Pending
 
-* Implement `EqGadget`, `CondSelectGadget`, and `R1CSVar` for `Vec<T>`
+* [\#93](https://github.com/arkworks-rs/r1cs-std/pull/93) Implement `EqGadget`, `CondSelectGadget`, and `R1CSVar` for `Vec<T>`
 
 ### Breaking changes