Port ProtoGalaxy from https://github.com/arnaucube/protogalaxy-poc ad…

…apting it to the current folding-schemes lib (#37)

Port ProtoGalaxy initial version from
https://github.com/arnaucube/protogalaxy-poc adapting it to the current
folding-schemes lib, which is a first iteration that implements the
Lagrange-basis version from
[ProtoGalaxy](https://eprint.iacr.org/2023/1106) folding scheme.  There
are some pending optimizations, but is a first step towards integrating
ProtoGalaxy in the library.

Cargo.toml

@@ -29,9 +29,7 @@ tracing = { version = "0.1", default-features = false, features = [ "attributes"
 tracing-subscriber = { version = "0.2" }
 
 [features]
-default = ["parallel", "nova", "hypernova"]
-hypernova=[]
-nova=[]
+default = ["parallel"]
 
 parallel = [ 
     "ark-std/parallel", 

src/decider/circuit.rs

@@ -48,7 +48,12 @@ pub fn vec_add<F: PrimeField>(
     b: &Vec<FpVar<F>>,
 ) -> Result<Vec<FpVar<F>>, Error> {
     if a.len() != b.len() {
-        return Err(Error::NotSameLength(a.len(), b.len()));
+        return Err(Error::NotSameLength(
+            "a.len()".to_string(),
+            a.len(),
+            "b.len()".to_string(),
+            b.len(),
+        ));
     }
     let mut r: Vec<FpVar<F>> = vec![FpVar::<F>::zero(); a.len()];
     for i in 0..a.len() {
@@ -68,7 +73,12 @@ pub fn hadamard<F: PrimeField>(
     b: &Vec<FpVar<F>>,
 ) -> Result<Vec<FpVar<F>>, Error> {
     if a.len() != b.len() {
-        return Err(Error::NotSameLength(a.len(), b.len()));
+        return Err(Error::NotSameLength(
+            "a.len()".to_string(),
+            a.len(),
+            "b.len()".to_string(),
+            b.len(),
+        ));
     }
     let mut r: Vec<FpVar<F>> = vec![FpVar::<F>::zero(); a.len()];
     for i in 0..a.len() {

src/folding/mod.rs

@@ -1,5 +1,4 @@
 pub mod circuits;
-#[cfg(feature = "hypernova")]
 pub mod hypernova;
-#[cfg(feature = "nova")]
 pub mod nova;
+pub mod protogalaxy;