Move the experimental frontends into a separate crate, so that when not using them they don't take several minutes to compile (and indirect dependencies). (#168)

This saves several minutes (and MBs of data) on compilation time both
when running tests in this repo, but also when using the sonobe lib as a
dependency in external repos.

.github/scripts/wasm-target-test-build.sh

@@ -15,7 +15,8 @@ cp "${GIT_ROOT}/rust-toolchain" .
 rustup target add wasm32-unknown-unknown wasm32-wasi 
 
 # add dependencies
-cargo add --path "${GIT_ROOT}/folding-schemes" --features wasm, parallel
+cargo add --path "${GIT_ROOT}/frontends" --features wasm, parallel
+cargo add --path "${GIT_ROOT}/folding-schemes" --features parallel
 cargo add getrandom --features js --target wasm32-unknown-unknown
 
 # test build for wasm32-* targets
@@ -26,4 +27,4 @@ cargo build --release --target wasm32-wasi
 
 # delete test project
 cd ../
-rm -rf foobar
+rm -rf foobar

.github/workflows/ci.yml

@@ -61,9 +61,9 @@ jobs:
           curl -sSfL https://github.com/ethereum/solidity/releases/download/v0.8.4/solc-static-linux -o /usr/local/bin/solc
           chmod +x /usr/local/bin/solc
       - name: Execute compile.sh to generate .r1cs and .wasm from .circom
-        run: ./folding-schemes/src/frontend/circom/test_folder/compile.sh
+        run: ./frontends/src/circom/test_folder/compile.sh
       - name: Execute compile.sh to generate .json from noir
-        run: ./folding-schemes/src/frontend/noir/test_folder/compile.sh
+        run: ./frontends/src/noir/test_folder/compile.sh
       - name: Run tests
         uses: actions-rs/cargo@v1
         with:
@@ -95,11 +95,16 @@ jobs:
           default: true
       - name: Add target
         run: rustup target add ${{ matrix.target }}
-      - name: Wasm-compat build
+      - name: Wasm-compat frontends build
         uses: actions-rs/cargo@v1
         with:
           command: build
-          args: -p folding-schemes --no-default-features --target ${{ matrix.target }} --features "wasm, parallel"
+          args: -p frontends --no-default-features --target ${{ matrix.target }} --features "wasm, parallel"
+      - name: Wasm-compat folding-schemes build
+        uses: actions-rs/cargo@v1
+        with:
+          command: build
+          args: -p folding-schemes --no-default-features --target ${{ matrix.target }} --features "default,light-test"
       - name: Run wasm-compat script
         run: |
           chmod +x .github/scripts/wasm-target-test-build.sh
@@ -127,9 +132,9 @@ jobs:
           curl -sSfL https://github.com/ethereum/solidity/releases/download/v0.8.4/solc-static-linux -o /usr/local/bin/solc
           chmod +x /usr/local/bin/solc
       - name: Execute compile.sh to generate .r1cs and .wasm from .circom
-        run: ./folding-schemes/src/frontend/circom/test_folder/compile.sh
+        run: ./frontends/src/circom/test_folder/compile.sh
       - name: Execute compile.sh to generate .json from noir
-        run: ./folding-schemes/src/frontend/noir/test_folder/compile.sh
+        run: ./frontends/src/noir/test_folder/compile.sh
       - name: Run examples tests
         run: cargo test --examples
       - name: Run examples
@@ -160,9 +165,9 @@ jobs:
         include:
           - feature_set: basic
             features: --features default,light-test
-            # We only want to test `folding-schemes` package with `wasm` feature.
+            # We only want to test `frontends` package with `wasm` feature.
           - feature_set: wasm
-            features: -p folding-schemes --features wasm,parallel --target wasm32-unknown-unknown
+            features: -p frontends --features wasm,parallel --target wasm32-unknown-unknown
     steps:
       - uses: actions/checkout@v2
       - uses: actions-rs/toolchain@v1

.gitignore

@@ -2,14 +2,14 @@
 Cargo.lock
 
 # Circom generated files
-folding-schemes/src/frontend/circom/test_folder/*_js/
+frontends/src/circom/test_folder/*_js/
 *.r1cs
 *.sym
 
 # Noir generated files
-folding-schemes/src/frontend/noir/test_folder/*/target/*
+frontends/src/noir/test_folder/*/target/*
 
-# generated contracts at test time
+# generated contracts data
 solidity-verifiers/generated
 examples/*.sol
 examples/*.calldata

Cargo.toml

@@ -2,7 +2,8 @@
 members = [
     "folding-schemes",
     "solidity-verifiers",
-    "cli"
+    "cli",
+    "frontends"
 ]
 resolver = "2"
 

README.md

@@ -13,7 +13,8 @@ Sonobe is conceived as an exploratory effort with the aim to push forward the pr
 <br>
 
 > **Warning**: experimental code, do not use in production.<br>
-> The code has not been audited. Several optimizations are also pending. Our focus so far has been on implementing the Nova and CycleFold schemes and achieving onchain (EVM) verification.
+> The code has not been audited. Several optimizations are also pending. Our focus so far has been on implementing the Nova, HyperNova and ProtoGalaxy schemes, all with the CycleFold approach; and achieving the onchain (in EVM) verification of the folding proofs.
+
 
 ## Schemes implemented
 
@@ -27,52 +28,42 @@ Work in progress:
 
 - [ProtoGalaxy: Efficient ProtoStar-style folding of multiple instances](https://eprint.iacr.org/2023/1106.pdf), Liam Eagen, Ariel Gabizon. 2023
 
-## Available frontends
 
-Available frontends to define the folded circuit:
+## Frontends
+
+Frontends allow to define the circuit to be folded (ie. `FCircuit`).
+The recommended frontend is directly implementing the [`FCircuit` trait](https://github.com/privacy-scaling-explorations/sonobe/blob/main/folding-schemes/src/frontend/mod.rs#L16) with the Arkworks constraint system.
+
+Alternatively, experimental frontends for [Circom](https://github.com/iden3/circom), [Noir](https://github.com/noir-lang/noir) and [Noname](https://github.com/zksecurity/noname) can be found at the [sonobe/frontends](https://github.com/privacy-scaling-explorations/sonobe/tree/main/frontends) directory, which have some computational (and time) overhead.
+
+More details about the frontend interface and the experimental frontends can be found at the [sonobe-docs/frontend](https://privacy-scaling-explorations.github.io/sonobe-docs/usage/frontend.html) page.
 
-- [arkworks](https://github.com/arkworks-rs), arkworks contributors
-- [Circom](https://github.com/iden3/circom), iden3, 0Kims Association
-- [Noname](https://github.com/zksecurity/noname), zkSecurity
 
 ## Usage
-
+Import the library:
-### Build & test
-You can test the library for both, WASM-targets and regular ones.
-#### Regular targets
-Tier-S targets allow the user to simply run `cargo test` or `cargo build` without needing to worry about anything.
-**We strongly recommend to test using the `light-test` feature.** Which will omit the computationally intensive parts of the tests such as
-generating a SNARK of 4~5M constraints to then verify it.
-
-#### WASM targets
-In order to build the lib for WASM-targets, use the following command:
-`cargo build -p folding-schemes --no-default-features --target wasm32-unknown-unknown --features "wasm, parallel"`.
-Where the target can be any WASM one and the `parallel` feature is optional.
-
-**Trying to build for a WASM-target without the `wasm` feature or viceversa will end up in a compilation error.**
-
-### Docs
-
-Detailed usage and design documentation can be found at [Sonobe docs](https://privacy-scaling-explorations.github.io/sonobe-docs/).
-
-### WASM-compatibility & features
-
-The `sonobe/folding-schemes` crate is the only workspace member that supports WASM-target compilation. But, to have it working, `getrandom/js` needs
-to be imported in the `Cargo.toml` of the crate that uses it as dependency.
 ```toml
 [dependencies]
-folding-schemes = { version = "0.1.0", default-features = false, features = ["parallel", "wasm"] }
+folding-schemes = { git = "https://github.com/privacy-scaling-explorations/sonobe", package = "folding-schemes"}
-getrandom = { version = "0.2", features = ["js"] }
 ```
-See more details about `getrandom` here: https://docs.rs/getrandom/latest/getrandom/#webassembly-support.
 
-Also, notice that:
+Available packages:
-- `wasm` feature **IS MANDATORY** if compilation to WASM targets is desired.
+- `folding-schemes`: main crate, contains the different scheme implementations, together with commitment schemes, frontend trait, arithmetization, transcript, etc.
-- `parallel` feature enables some parallelization optimizations available in the crate.
+- `solidity-verifiers`: contains the templating logic to output the verifier contracts for the DeciderEth proofs. Currently only supports Nova+CycleFold DeciderEth proofs.
-- `light-test` feature runs the computationally-intensive parts of the testing such as the full proof generation for the Eth-decider circuit
+- `frontends`: contains the experimental frontends other than the arkworks frontend. More details at the [sonobe/frontends](https://github.com/privacy-scaling-explorations/sonobe/tree/main/frontends) directory.
-of Nova which is approximately 4-5M constraints. **This feature only matters when it comes to running Sonobe's tests.**
 
-### Folding Schemes introduction
+Available features:
+- `parallel` enables some parallelization optimizations available in the crate. It is enabled by default.
+- `light-test` disables part of the DeciderEthCircuit various circuits (which accounts for ~9M constraints) so that the tests involving those circuits can run faster. Do not use it outside tests. This feature is disabled by default.
+
+Examples of usage can be found at the [examples](https://github.com/privacy-scaling-explorations/sonobe/tree/main/examples) directory.
+
+For WASM (in browser usage), details can be found at [sonobe-docs/usage/wasm](https://privacy-scaling-explorations.github.io/sonobe-docs/usage/wasm.html).
+
+
+### Docs
+Details on usage of the library, together with design documentation, can be found at the [Sonobe docs](https://privacy-scaling-explorations.github.io/sonobe-docs/).
+
+## Folding Schemes introduction
 
 Folding schemes efficiently achieve incrementally verifiable computation (IVC), where the prover recursively proves the correct execution of the incremental computations.
 Once the IVC iterations are completed, the IVC proof is compressed into the Decider proof, a zkSNARK proof which proves that applying $n$ times the $F$ function (the circuit being folded) to the initial state ($z_0$) results in the final state ($z_n$).

examples/circom_full_flow.rs

@@ -23,10 +23,11 @@ use folding_schemes::{
         decider_eth::{prepare_calldata, Decider as DeciderEth},
         Nova, PreprocessorParam,
     },
-    frontend::{circom::CircomFCircuit, FCircuit},
+    frontend::FCircuit,
     transcript::poseidon::poseidon_canonical_config,
     Decider, FoldingScheme,
 };
+use frontends::circom::CircomFCircuit;
 use solidity_verifiers::{
     evm::{compile_solidity, Evm},
     utils::get_function_selector_for_nova_cyclefold_verifier,
@@ -54,11 +55,9 @@ fn main() {
     ];
 
     // initialize the Circom circuit
-    let r1cs_path = PathBuf::from(
+    let r1cs_path = PathBuf::from("./frontends/src/circom/test_folder/with_external_inputs.r1cs");
-        "./folding-schemes/src/frontend/circom/test_folder/with_external_inputs.r1cs",
-    );
     let wasm_path = PathBuf::from(
-        "./folding-schemes/src/frontend/circom/test_folder/with_external_inputs_js/with_external_inputs.wasm",
+        "./frontends/src/circom/test_folder/with_external_inputs_js/with_external_inputs.wasm",
     );
 
     let f_circuit_params = (r1cs_path.into(), wasm_path.into(), 1, 2);

examples/noir_full_flow.rs

@@ -20,13 +20,11 @@ use folding_schemes::{
         decider_eth::{prepare_calldata, Decider as DeciderEth},
         Nova, PreprocessorParam,
     },
-    frontend::{
+    frontend::FCircuit,
-        noir::{load_noir_circuit, NoirFCircuit},
-        FCircuit,
-    },
     transcript::poseidon::poseidon_canonical_config,
     Decider, FoldingScheme,
 };
+use frontends::noir::{load_noir_circuit, NoirFCircuit};
 use std::{env, time::Instant};
 
 use solidity_verifiers::{
@@ -44,7 +42,7 @@ fn main() {
     let cur_path = env::current_dir().unwrap();
 
     let circuit_path = format!(
-        "{}/folding-schemes/src/frontend/noir/test_folder/test_mimc/target/test_mimc.json",
+        "{}/frontends/src/noir/test_folder/test_mimc/target/test_mimc.json",
         cur_path.to_str().unwrap()
     );
 

examples/noname_full_flow.rs

@@ -21,10 +21,11 @@ use folding_schemes::{
         decider_eth::{prepare_calldata, Decider as DeciderEth},
         Nova, PreprocessorParam,
     },
-    frontend::{noname::NonameFCircuit, FCircuit},
+    frontend::FCircuit,
     transcript::poseidon::poseidon_canonical_config,
     Decider, FoldingScheme,
 };
+use frontends::noname::NonameFCircuit;
 use std::time::Instant;
 
 use solidity_verifiers::{

folding-schemes/Cargo.toml

@@ -9,28 +9,20 @@ ark-ff = { version = "^0.4.0", default-features = false, features = ["parallel",
 ark-poly = { version = "^0.4.0", default-features = false, features = ["parallel"] }
 ark-std = { version = "^0.4.0", default-features = false, features = ["parallel"] }
 ark-crypto-primitives = { version = "^0.4.0", default-features = false, features = ["r1cs", "sponge", "crh", "parallel"] }
-ark-grumpkin = { version = "0.4.0", default-features = false }
 ark-poly-commit = { version = "^0.4.0", default-features = false, features = ["parallel"] }
 ark-relations = { version = "^0.4.0", default-features = false }
-# this is patched at the workspace level
+# ark-r1cs-std is patched at the workspace level
 ark-r1cs-std = { version = "0.4.0", default-features = false, features = ["parallel"] }
 ark-snark = { version = "^0.4.0", default-features = false }
 ark-serialize = { version = "^0.4.0", default-features = false }
-ark-circom = { git = "https://github.com/arnaucube/circom-compat", default-features = false }
 ark-groth16 = { version = "^0.4.0", default-features = false, features = ["parallel"]}
 ark-bn254 = { version = "^0.4.0", default-features = false }
+ark-grumpkin = { version = "0.4.0", default-features = false }
 thiserror = "1.0"
 rayon = "1"
 num-bigint = "0.4"
 num-integer = "0.1"
-color-eyre = "=0.6.2"
 sha3 = "0.10"
-ark-noname = { git = "https://github.com/dmpierre/ark-noname", branch = "feat/sonobe-integration" }
-noname = { git = "https://github.com/dmpierre/noname" }
-serde_json = "1.0.85"                                                                # to (de)serialize JSON
-serde = "1.0.203"
-acvm = { git = "https://github.com/noir-lang/noir", rev="2b4853e", default-features = false }
-noir_arkworks_backend = { package="arkworks_backend", git = "https://github.com/dmpierre/arkworks_backend", branch = "feat/sonobe-integration" }
 log = "0.4"
 
 # tmp import for espresso's sumcheck
@@ -46,6 +38,7 @@ ark-grumpkin = {version="0.4.0", features=["r1cs"]}
 ark-mnt4-298 = {version="0.4.0", features=["r1cs"]}
 ark-mnt6-298 = {version="0.4.0", features=["r1cs"]}
 rand = "0.8.5"
+num-bigint = {version = "0.4", features = ["rand"]}
 tracing = { version = "0.1", default-features = false, features = [ "attributes" ] }
 tracing-subscriber = { version = "0.2" }
 
@@ -55,9 +48,8 @@ tracing-subscriber = { version = "0.2" }
 getrandom = { version = "0.2", features = ["js"] }
 
 [features]
-default = ["ark-circom/default", "parallel"]
+default = ["parallel"]
 parallel = []
-wasm = ["ark-circom/wasm"]
 light-test = []
 
 

folding-schemes/src/folding/nova/zk.rs

@@ -15,13 +15,13 @@
 ///     final proof generation to a server.
 /// * Use-case-2: at the end of all the IVC folding steps (after n iterations of nova.prove_step),
 ///   to 'blind' the IVC proof so then it can be sent to a server that will generate the final
-///   decider snark proof.
+///   decider SNARK proof.
 ///     --> In this one, the user could externalize the Decider final proof generation to a
 ///     server.
 /// * Use-case-3: the user does not care about the Decider (final compressed SNARK proof), and
 ///   wants to generate a zk-proof of the IVC state to an IVC verifier (without any SNARK proof
-///   involved). Note that this proof will be much bigger and expensive to verify than a Decider
+///   involved). In this use-case, the zk is only added at the last IVCProof. Note that this proof
-///   SNARK proof.
+///   will be much bigger and expensive to verify than a Decider SNARK proof.
 ///
 /// The current implementation covers the Use-case-3.
 /// Use-case-1 can be achieved directly by a simpler version of the zk IVC scheme skipping steps

folding-schemes/src/frontend/circom/test_folder/compile.sh

@@ -1,4 +0,0 @@
-#!/bin/bash
-circom ./folding-schemes/src/frontend/circom/test_folder/cubic_circuit.circom --r1cs --sym --wasm --prime bn128 --output ./folding-schemes/src/frontend/circom/test_folder/
-circom ./folding-schemes/src/frontend/circom/test_folder/with_external_inputs.circom --r1cs --sym --wasm --prime bn128 --output ./folding-schemes/src/frontend/circom/test_folder/
-circom ./folding-schemes/src/frontend/circom/test_folder/no_external_inputs.circom --r1cs --sym --wasm --prime bn128 --output ./folding-schemes/src/frontend/circom/test_folder/

folding-schemes/src/frontend/mod.rs

@@ -4,9 +4,6 @@ use ark_r1cs_std::fields::fp::FpVar;
 use ark_relations::r1cs::{ConstraintSystemRef, SynthesisError};
 use ark_std::fmt::Debug;
 
-pub mod circom;
-pub mod noir;
-pub mod noname;
 pub mod utils;
 
 /// FCircuit defines the trait of the circuit of the F function, which is the one being folded (ie.

folding-schemes/src/frontend/utils.rs

@@ -152,14 +152,12 @@ impl<F: PrimeField> FCircuit<F> for CustomFCircuit<F> {
 /// than the one done in the `AugmentedFCircuit`, but without adding all the extra constraints
 /// of the AugmentedF circuit logic, in order to run lighter tests when we're not interested in
 /// the the AugmentedF logic but in the wrapping of the circuits.
-#[cfg(test)]
 pub struct WrapperCircuit<F: PrimeField, FC: FCircuit<F>> {
     pub FC: FC, // F circuit
     pub z_i: Option<Vec<F>>,
     pub z_i1: Option<Vec<F>>,
 }
 
-#[cfg(test)]
 impl<F, FC> ark_relations::r1cs::ConstraintSynthesizer<F> for WrapperCircuit<F, FC>
 where
     F: PrimeField,

frontends/Cargo.toml

@@ -0,0 +1,33 @@
+[package]
+name = "frontends"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+ark-ff = { version = "^0.4.0", default-features = false, features = ["parallel", "asm"] }
+ark-std = { version = "^0.4.0", default-features = false, features = ["parallel"] }
+ark-relations = { version = "^0.4.0", default-features = false }
+# ark-r1cs-std is patched at the workspace level
+ark-r1cs-std = { version = "0.4.0", default-features = false, features = ["parallel"] }
+ark-serialize = { version = "^0.4.0", default-features = false }
+ark-circom = { git = "https://github.com/arnaucube/circom-compat", default-features = false }
+num-bigint = "0.4"
+ark-noname = { git = "https://github.com/dmpierre/ark-noname", branch = "feat/sonobe-integration" }
+noname = { git = "https://github.com/dmpierre/noname" }
+serde_json = "1.0.85"                                                                # to (de)serialize JSON
+acvm = { git = "https://github.com/noir-lang/noir", rev="2b4853e", default-features = false }
+noir_arkworks_backend = { package="arkworks_backend", git = "https://github.com/dmpierre/arkworks_backend", branch = "feat/sonobe-integration" }
+folding-schemes = { path = "../folding-schemes/"}
+
+[dev-dependencies]
+ark-bn254 = {version="0.4.0", features=["r1cs"]}
+
+# This allows the crate to be built when targeting WASM.
+# See more at: https://docs.rs/getrandom/#webassembly-support 
+[target.'cfg(all(target_arch = "wasm32", target_os = "unknown"))'.dependencies]
+getrandom = { version = "0.2", features = ["js"] }
+
+[features]
+default = ["ark-circom/default", "parallel"]
+parallel = []
+wasm = ["ark-circom/wasm"]

frontends/README.md

@@ -0,0 +1,18 @@
+# frontends
+
+This crate contains *experimental frontends* for Sonobe.
+The recommended frontend is to directly use [arkworks](https://github.com/arkworks-rs) to define the FCircuit, just following the [`FCircuit` trait](https://github.com/privacy-scaling-explorations/sonobe/blob/main/folding-schemes/src/frontend/mod.rs).
+
+## Experimental frontends
+> Warning: the following frontends are experimental and some computational and time overhead is expected when using them compared to directly using the [arkworks frontend](https://github.com/privacy-scaling-explorations/sonobe/blob/main/folding-schemes/src/frontend/mod.rs).
+
+Available experimental frontends:
+- [Circom](https://github.com/iden3/circom), iden3, 0Kims Association. Supported version`<=v2.1.9`.
+- [Noir](https://github.com/noir-lang/noir), Aztec.
+- [Noname](https://github.com/zksecurity/noname), zkSecurity. Partially supported.
+
+
+Documentation about frontend interface and experimental frontends: https://privacy-scaling-explorations.github.io/sonobe-docs/usage/frontend.html
+
+## Implementing new frontends
+Support for new frontends can be added (even from outside this repo) by implementing the [`FCircuit` trait](https://github.com/privacy-scaling-explorations/sonobe/blob/main/folding-schemes/src/frontend/mod.rs).

frontends/src/circom/mod.rs

@@ -1,14 +1,12 @@
-use crate::frontend::FCircuit;
-use crate::frontend::FpVar::Var;
-use crate::utils::PathOrBin;
-use crate::Error;
 use ark_circom::circom::{CircomCircuit, R1CS as CircomR1CS};
 use ark_ff::PrimeField;
 use ark_r1cs_std::alloc::AllocVar;
 use ark_r1cs_std::fields::fp::FpVar;
+use ark_r1cs_std::fields::fp::FpVar::Var;
 use ark_r1cs_std::R1CSVar;
 use ark_relations::r1cs::{ConstraintSynthesizer, ConstraintSystemRef, SynthesisError};
 use ark_std::fmt::Debug;
+use folding_schemes::{frontend::FCircuit, utils::PathOrBin, Error};
 use num_bigint::BigInt;
 use std::rc::Rc;
 use std::{fmt, usize};
@@ -187,10 +185,10 @@ impl<F: PrimeField> FCircuit<F> for CircomFCircuit<F> {
 }
 
 impl<F: PrimeField> CircomFCircuit<F> {
-    fn fpvars_to_bigints(&self, fpVars: &[FpVar<F>]) -> Result<Vec<BigInt>, SynthesisError> {
+    fn fpvars_to_bigints(&self, fpvars: &[FpVar<F>]) -> Result<Vec<BigInt>, SynthesisError> {
         let mut input_values = Vec::new();
         // converts each FpVar to PrimeField value, then to num_bigint::BigInt.
-        for fp_var in fpVars.iter() {
+        for fp_var in fpvars.iter() {
             // extracts the PrimeField value from FpVar.
             let primefield_value = fp_var.value()?;
             // converts the PrimeField value to num_bigint::BigInt.
@@ -213,9 +211,9 @@ pub mod tests {
     // Tests the step_native function of CircomFCircuit.
     #[test]
     fn test_circom_step_native() {
-        let r1cs_path = PathBuf::from("./src/frontend/circom/test_folder/cubic_circuit.r1cs");
+        let r1cs_path = PathBuf::from("./src/circom/test_folder/cubic_circuit.r1cs");
         let wasm_path =
-            PathBuf::from("./src/frontend/circom/test_folder/cubic_circuit_js/cubic_circuit.wasm");
+            PathBuf::from("./src/circom/test_folder/cubic_circuit_js/cubic_circuit.wasm");
 
         let circom_fcircuit =
             CircomFCircuit::<Fr>::new((r1cs_path.into(), wasm_path.into(), 1, 0)).unwrap(); // state_len:1, external_inputs_len:0
@@ -228,9 +226,9 @@ pub mod tests {
     // Tests the generate_step_constraints function of CircomFCircuit.
     #[test]
     fn test_circom_step_constraints() {
-        let r1cs_path = PathBuf::from("./src/frontend/circom/test_folder/cubic_circuit.r1cs");
+        let r1cs_path = PathBuf::from("./src/circom/test_folder/cubic_circuit.r1cs");
         let wasm_path =
-            PathBuf::from("./src/frontend/circom/test_folder/cubic_circuit_js/cubic_circuit.wasm");
+            PathBuf::from("./src/circom/test_folder/cubic_circuit_js/cubic_circuit.wasm");
 
         let circom_fcircuit =
             CircomFCircuit::<Fr>::new((r1cs_path.into(), wasm_path.into(), 1, 0)).unwrap(); // state_len:1, external_inputs_len:0
@@ -249,16 +247,16 @@ pub mod tests {
     // Tests the WrapperCircuit with CircomFCircuit.
     #[test]
     fn test_wrapper_circomtofcircuit() {
-        let r1cs_path = PathBuf::from("./src/frontend/circom/test_folder/cubic_circuit.r1cs");
+        let r1cs_path = PathBuf::from("./src/circom/test_folder/cubic_circuit.r1cs");
         let wasm_path =
-            PathBuf::from("./src/frontend/circom/test_folder/cubic_circuit_js/cubic_circuit.wasm");
+            PathBuf::from("./src/circom/test_folder/cubic_circuit_js/cubic_circuit.wasm");
 
         let circom_fcircuit =
             CircomFCircuit::<Fr>::new((r1cs_path.into(), wasm_path.into(), 1, 0)).unwrap(); // state_len:1, external_inputs_len:0
 
         // Allocates z_i1 by using step_native function.
         let z_i = vec![Fr::from(3_u32)];
-        let wrapper_circuit = crate::frontend::utils::WrapperCircuit {
+        let wrapper_circuit = folding_schemes::frontend::utils::WrapperCircuit {
             FC: circom_fcircuit.clone(),
             z_i: Some(z_i.clone()),
             z_i1: Some(circom_fcircuit.step_native(0, z_i.clone(), vec![]).unwrap()),
@@ -275,10 +273,9 @@ pub mod tests {
 
     #[test]
     fn test_circom_external_inputs() {
-        let r1cs_path =
+        let r1cs_path = PathBuf::from("./src/circom/test_folder/with_external_inputs.r1cs");
-            PathBuf::from("./src/frontend/circom/test_folder/with_external_inputs.r1cs");
         let wasm_path = PathBuf::from(
-            "./src/frontend/circom/test_folder/with_external_inputs_js/with_external_inputs.wasm",
+            "./src/circom/test_folder/with_external_inputs_js/with_external_inputs.wasm",
         );
         let circom_fcircuit =
             CircomFCircuit::<Fr>::new((r1cs_path.into(), wasm_path.into(), 1, 2)).unwrap(); // state_len:1, external_inputs_len:2
@@ -320,10 +317,9 @@ pub mod tests {
 
     #[test]
     fn test_circom_no_external_inputs() {
-        let r1cs_path = PathBuf::from("./src/frontend/circom/test_folder/no_external_inputs.r1cs");
+        let r1cs_path = PathBuf::from("./src/circom/test_folder/no_external_inputs.r1cs");
-        let wasm_path = PathBuf::from(
+        let wasm_path =
-            "./src/frontend/circom/test_folder/no_external_inputs_js/no_external_inputs.wasm",
+            PathBuf::from("./src/circom/test_folder/no_external_inputs_js/no_external_inputs.wasm");
-        );
         let circom_fcircuit =
             CircomFCircuit::<Fr>::new((r1cs_path.into(), wasm_path.into(), 3, 0)).unwrap();
         let cs = ConstraintSystem::<Fr>::new_ref();
@@ -353,9 +349,9 @@ pub mod tests {
 
     #[test]
     fn test_custom_code() {
-        let r1cs_path = PathBuf::from("./src/frontend/circom/test_folder/cubic_circuit.r1cs");
+        let r1cs_path = PathBuf::from("./src/circom/test_folder/cubic_circuit.r1cs");
         let wasm_path =
-            PathBuf::from("./src/frontend/circom/test_folder/cubic_circuit_js/cubic_circuit.wasm");
+            PathBuf::from("./src/circom/test_folder/cubic_circuit_js/cubic_circuit.wasm");
 
         let mut circom_fcircuit =
             CircomFCircuit::<Fr>::new((r1cs_path.into(), wasm_path.into(), 1, 0)).unwrap(); // state_len:1, external_inputs_len:0
@@ -367,7 +363,7 @@ pub mod tests {
 
         // Allocates z_i1 by using step_native function.
         let z_i = vec![Fr::from(3_u32)];
-        let wrapper_circuit = crate::frontend::utils::WrapperCircuit {
+        let wrapper_circuit = folding_schemes::frontend::utils::WrapperCircuit {
             FC: circom_fcircuit.clone(),
             z_i: Some(z_i.clone()),
             z_i1: Some(circom_fcircuit.step_native(0, z_i.clone(), vec![]).unwrap()),

frontends/src/circom/test_folder/compile.sh

@@ -0,0 +1,4 @@
+#!/bin/bash
+circom ./frontends/src/circom/test_folder/cubic_circuit.circom --r1cs --sym --wasm --prime bn128 --output ./frontends/src/circom/test_folder/
+circom ./frontends/src/circom/test_folder/with_external_inputs.circom --r1cs --sym --wasm --prime bn128 --output ./frontends/src/circom/test_folder/
+circom ./frontends/src/circom/test_folder/no_external_inputs.circom --r1cs --sym --wasm --prime bn128 --output ./frontends/src/circom/test_folder/

frontends/src/circom/utils.rs

@@ -4,11 +4,10 @@ use ark_circom::{
 };
 use ark_ff::{BigInteger, PrimeField};
 use ark_serialize::Read;
-use color_eyre::Result;
 use num_bigint::{BigInt, Sign};
 use std::{fs::File, io::Cursor, marker::PhantomData, path::PathBuf};
 
-use crate::{utils::PathOrBin, Error};
+use folding_schemes::{utils::PathOrBin, Error};
 
 // A struct that wraps Circom functionalities, allowing for extraction of R1CS and witnesses
 // based on file paths to Circom's .r1cs and .wasm.
@@ -134,14 +133,14 @@ mod tests {
     use ark_relations::r1cs::{ConstraintSynthesizer, ConstraintSystem};
 
     //To generate .r1cs and .wasm files, run the below command in the terminal.
-    //bash ./folding-schemes/src/frontend/circom/test_folder/compile.sh
+    //bash ./frontends/src/circom/test_folder/compile.sh
 
     // Test the satisfication by using the CircomBuilder of circom-compat
     #[test]
     fn test_circombuilder_satisfied() {
         let cfg = CircomConfig::<Fr>::new(
-            "./src/frontend/circom/test_folder/cubic_circuit_js/cubic_circuit.wasm",
+            "./src/circom/test_folder/cubic_circuit_js/cubic_circuit.wasm",
-            "./src/frontend/circom/test_folder/cubic_circuit.r1cs",
+            "./src/circom/test_folder/cubic_circuit.r1cs",
         )
         .unwrap();
         let mut builder = CircomBuilder::new(cfg);
@@ -156,9 +155,9 @@ mod tests {
     // Test the satisfication by using the CircomWrapper
     #[test]
     fn test_extract_r1cs_and_witness() {
-        let r1cs_path = PathBuf::from("./src/frontend/circom/test_folder/cubic_circuit.r1cs");
+        let r1cs_path = PathBuf::from("./src/circom/test_folder/cubic_circuit.r1cs");
         let wasm_path =
-            PathBuf::from("./src/frontend/circom/test_folder/cubic_circuit_js/cubic_circuit.wasm");
+            PathBuf::from("./src/circom/test_folder/cubic_circuit_js/cubic_circuit.wasm");
 
         let inputs = vec![("ivc_input".to_string(), vec![BigInt::from(3)])];
         let wrapper = CircomWrapper::<Fr>::new(r1cs_path.into(), wasm_path.into()).unwrap();

frontends/src/lib.rs

@@ -0,0 +1,3 @@
+pub mod circom;
+pub mod noir;
+pub mod noname;

frontends/src/noir/mod.rs

@@ -1,8 +1,5 @@
 use std::collections::HashMap;
 
-use crate::{utils::PathOrBin, Error};
-
-use super::FCircuit;
 use acvm::{
     acir::{
         acir_field::GenericFieldElement,
@@ -16,6 +13,7 @@ use ark_ff::PrimeField;
 use ark_r1cs_std::{alloc::AllocVar, fields::fp::FpVar, R1CSVar};
 use ark_relations::r1cs::ConstraintSynthesizer;
 use ark_relations::r1cs::{ConstraintSystemRef, SynthesisError};
+use folding_schemes::{frontend::FCircuit, utils::PathOrBin, Error};
 use noir_arkworks_backend::{
     read_program_from_binary, read_program_from_file, sonobe_bridge::AcirCircuitSonobe,
 };
@@ -30,7 +28,7 @@ pub struct NoirFCircuit<F: PrimeField> {
 impl<F: PrimeField> FCircuit<F> for NoirFCircuit<F> {
     type Params = (PathOrBin, usize, usize);
 
-    fn new(params: Self::Params) -> Result<Self, crate::Error> {
+    fn new(params: Self::Params) -> Result<Self, Error> {
         let (source, state_len, external_inputs_len) = params;
         let program = match source {
             PathOrBin::Path(path) => read_program_from_file(path),
@@ -70,7 +68,7 @@ impl<F: PrimeField> FCircuit<F> for NoirFCircuit<F> {
         _i: usize,
         z_i: Vec<F>,
         external_inputs: Vec<F>, // inputs that are not part of the state
-    ) -> Result<Vec<F>, crate::Error> {
+    ) -> Result<Vec<F>, Error> {
         let mut acvm = ACVM::new(
             &StubbedBlackBoxSolver,
             &self.circuit.opcodes,
@@ -226,20 +224,21 @@ pub fn load_noir_circuit<F: PrimeField>(path: String) -> Circuit<GenericFieldEle
 
 #[cfg(test)]
 mod tests {
-    use crate::frontend::{noir::load_noir_circuit, FCircuit};
+    use crate::noir::load_noir_circuit;
     use ark_bn254::Fr;
     use ark_r1cs_std::R1CSVar;
     use ark_r1cs_std::{alloc::AllocVar, fields::fp::FpVar};
     use ark_relations::r1cs::ConstraintSystem;
+    use folding_schemes::frontend::FCircuit;
     use std::env;
 
-    use crate::frontend::noir::NoirFCircuit;
+    use crate::noir::NoirFCircuit;
 
     #[test]
     fn test_step_native() {
         let cur_path = env::current_dir().unwrap();
         let circuit_path = format!(
-            "{}/src/frontend/noir/test_folder/test_circuit/target/test_circuit.json",
+            "{}/src/noir/test_folder/test_circuit/target/test_circuit.json",
             cur_path.to_str().unwrap()
         );
         let circuit = load_noir_circuit(circuit_path);
@@ -259,7 +258,7 @@ mod tests {
         let cs = ConstraintSystem::<Fr>::new_ref();
         let cur_path = env::current_dir().unwrap();
         let circuit_path = format!(
-            "{}/src/frontend/noir/test_folder/test_circuit/target/test_circuit.json",
+            "{}/src/noir/test_folder/test_circuit/target/test_circuit.json",
             cur_path.to_str().unwrap()
         );
         let circuit = load_noir_circuit(circuit_path);
@@ -283,7 +282,7 @@ mod tests {
         let cs = ConstraintSystem::<Fr>::new_ref();
         let cur_path = env::current_dir().unwrap();
         let circuit_path = format!(
-            "{}/src/frontend/noir/test_folder/test_no_external_inputs/target/test_no_external_inputs.json",
+            "{}/src/noir/test_folder/test_no_external_inputs/target/test_no_external_inputs.json",
             cur_path.to_str().unwrap()
         );
         let circuit = load_noir_circuit(circuit_path);

frontends/src/noir/test_folder/compile.sh

@@ -1,6 +1,6 @@
 #!/bin/bash
 CUR_DIR=$(pwd)
-TEST_PATH="${CUR_DIR}/folding-schemes/src/frontend/noir/test_folder/"
+TEST_PATH="${CUR_DIR}/frontends/src/noir/test_folder/"
 for test_path in test_circuit test_mimc test_no_external_inputs; do
 	FOLDER="${TEST_PATH}${test_path}/"
 	cd ${FOLDER} && nargo compile && cd ${TEST_PATH}

frontends/src/noname/mod.rs

@@ -1,4 +1,3 @@
-use crate::Error;
 use ark_noname::sonobe::NonameSonobeCircuit;
 use ark_r1cs_std::alloc::AllocVar;
 use ark_r1cs_std::fields::fp::FpVar;
@@ -8,9 +7,9 @@ use std::marker::PhantomData;
 
 use self::utils::NonameInputs;
 
-use super::FCircuit;
 use ark_ff::PrimeField;
 use ark_noname::utils::compile_source_code;
+use folding_schemes::{frontend::FCircuit, Error};
 use noname::backends::{r1cs::R1CS as R1CSNoname, BackendField};
 use noname::witness::CompiledCircuit;
 pub mod utils;
@@ -25,7 +24,7 @@ pub struct NonameFCircuit<F: PrimeField, BF: BackendField> {
 impl<F: PrimeField, BF: BackendField> FCircuit<F> for NonameFCircuit<F, BF> {
     type Params = (String, usize, usize);
 
-    fn new(params: Self::Params) -> Result<Self, crate::Error> {
+    fn new(params: Self::Params) -> Result<Self, Error> {
         let (code, state_len, external_inputs_len) = params;
         let compiled_circuit = compile_source_code::<BF>(&code).map_err(|_| {
             Error::Other("Encountered an error while compiling a noname circuit".to_owned())
@@ -51,7 +50,7 @@ impl<F: PrimeField, BF: BackendField> FCircuit<F> for NonameFCircuit<F, BF> {
         _i: usize,
         z_i: Vec<F>,
         external_inputs: Vec<F>,
-    ) -> Result<Vec<F>, crate::Error> {
+    ) -> Result<Vec<F>, Error> {
         let wtns_external_inputs =
             NonameInputs::from((&external_inputs, "external_inputs".to_string()));
         let wtns_ivc_inputs = NonameInputs::from((&z_i, "ivc_inputs".to_string()));
@@ -119,7 +118,7 @@ mod tests {
     use ark_r1cs_std::{alloc::AllocVar, fields::fp::FpVar, R1CSVar};
     use noname::backends::r1cs::R1csBn254Field;
 
-    use crate::frontend::FCircuit;
+    use folding_schemes::frontend::FCircuit;
 
     use super::NonameFCircuit;
     use ark_relations::r1cs::ConstraintSystem;

solidity-verifiers/Cargo.toml

@@ -29,6 +29,7 @@ ark-bn254 = {version="0.4.0", features=["r1cs"]}
 ark-grumpkin = {version="0.4.0", features=["r1cs"]}
 rand = "0.8.5"
 folding-schemes = { path = "../folding-schemes/", features=["light-test"]}
+frontends = { path = "../frontends/"}
 noname = { git = "https://github.com/dmpierre/noname" }
 
 [features]