From 73f24a32b9be36104a5bd691963b8911de1269a6 Mon Sep 17 00:00:00 2001
From: Tom French <15848336+TomAFrench@users.noreply.github.com>
Date: Tue, 26 Mar 2024 19:41:31 +0000
Subject: [PATCH] chore: delete `R1CSTransformer` (#4649)

# Description

## Problem\*

Resolves <!-- Link to GitHub Issue -->

## Summary\*

The R1CS transformer is currently a no-op as the expression width is
unbounded and we guarantee that expressions will be at most degree 2 by
default.

It also looks increasingly likely that the CSAT transformer code will be
moved into the acir_gen pass so this is redundant.

## Additional Context



## Documentation\*

Check one:
- [x] No documentation needed.
- [ ] Documentation included in this PR.
- [ ] **[For Experimental Features]** Documentation to be submitted in a
separate PR.

# PR Checklist\*

- [x] I have tested the changes locally.
- [x] I have formatted the changes with [Prettier](https://prettier.io/)
and/or `cargo fmt` on default settings.
---
 acvm-repo/acvm/src/compiler/transformers/mod.rs  |  5 +----
 acvm-repo/acvm/src/compiler/transformers/r1cs.rs | 16 ----------------
 2 files changed, 1 insertion(+), 20 deletions(-)
 delete mode 100644 acvm-repo/acvm/src/compiler/transformers/r1cs.rs

diff --git a/acvm-repo/acvm/src/compiler/transformers/mod.rs b/acvm-repo/acvm/src/compiler/transformers/mod.rs
index 2e549854521..18f49c154f1 100644
--- a/acvm-repo/acvm/src/compiler/transformers/mod.rs
+++ b/acvm-repo/acvm/src/compiler/transformers/mod.rs
@@ -6,10 +6,8 @@ use acir::{
 use indexmap::IndexMap;
 
 mod csat;
-mod r1cs;
 
 pub(crate) use csat::CSatTransformer;
-pub(crate) use r1cs::R1CSTransformer;
 
 use super::{transform_assert_messages, AcirTransformationMap};
 
@@ -43,8 +41,7 @@ pub(super) fn transform_internal(
 ) -> (Circuit, Vec<usize>) {
     let mut transformer = match &expression_width {
         ExpressionWidth::Unbounded => {
-            let transformer = R1CSTransformer::new(acir);
-            return (transformer.transform(), acir_opcode_positions);
+            return (acir, acir_opcode_positions);
         }
         ExpressionWidth::Bounded { width } => {
             let mut csat = CSatTransformer::new(*width);
diff --git a/acvm-repo/acvm/src/compiler/transformers/r1cs.rs b/acvm-repo/acvm/src/compiler/transformers/r1cs.rs
deleted file mode 100644
index 3bdd29c9c53..00000000000
--- a/acvm-repo/acvm/src/compiler/transformers/r1cs.rs
+++ /dev/null
@@ -1,16 +0,0 @@
-use acir::circuit::Circuit;
-
-/// Currently a "noop" transformer.
-pub(crate) struct R1CSTransformer {
-    acir: Circuit,
-}
-
-impl R1CSTransformer {
-    pub(crate) fn new(acir: Circuit) -> Self {
-        Self { acir }
-    }
-    // TODO: We could possibly make sure that all polynomials are at most degree-2
-    pub(crate) fn transform(self) -> Circuit {
-        self.acir
-    }
-}