@@ -1,55 +1,6 @@
-//use bindgen;
-//use std::env;
-//use std::fs;
 use std::path::absolute;
-//use std::path::PathBuf;
-//use std::time::SystemTime;
 
 fn main() {
-    /*
-
-    [build-dependencies]
-    bindgen ="0.71.1"
-
-    // Path to the C header file
-    let header_paths: [&str; 2] = [
-        "spqlios-arithmetic/spqlios/coeffs/coeffs_arithmetic.h",
-        "spqlios-arithmetic/spqlios/arithmetic/vec_znx_arithmetic.h",
-    ];
-
-    let out_path: PathBuf = PathBuf::from(env::var("OUT_DIR").unwrap());
-    let bindings_file = out_path.join("bindings.rs");
-
-    let regenerate: bool = header_paths.iter().any(|header| {
-        let header_metadata: SystemTime = fs::metadata(header)
-            .and_then(|m| m.modified())
-            .unwrap_or(SystemTime::UNIX_EPOCH);
-        let bindings_metadata: SystemTime = fs::metadata(&bindings_file)
-            .and_then(|m| m.modified())
-            .unwrap_or(SystemTime::UNIX_EPOCH);
-        header_metadata > bindings_metadata
-    });
-
-    if regenerate {
-        // Generate the Rust bindings
-        let mut builder: bindgen::Builder = bindgen::Builder::default();
-        for header in header_paths {
-            builder = builder.header(header);
-        }
-
-        let bindings = builder
-            .generate_comments(false) // Optional: includes comments in bindings
-            .generate_inline_functions(true) // Optional: includes inline functions
-            .generate()
-            .expect("Unable to generate bindings");
-
-        // Write the bindings to the OUT_DIR
-        bindings
-            .write_to_file(&bindings_file)
-            .expect("Couldn't write bindings!");
-    }
-    */
-
     println!(
         "cargo:rustc-link-search=native={}",
         absolute("./spqlios-arithmetic/build/spqlios")

@@ -0,0 +1,36 @@
+/*
+[build-dependencies]
+bindgen ="0.71.1"
+
+//use bindgen;
+//use std::env;
+//use std::fs;
+//use std::path::PathBuf;
+//use std::time::SystemTime;
+
+// Path to the C header file
+let header_paths: [&str; 2] = [
+    "spqlios-arithmetic/spqlios/coeffs/coeffs_arithmetic.h",
+    "spqlios-arithmetic/spqlios/arithmetic/vec_znx_arithmetic.h",
+];
+
+let out_path: PathBuf = PathBuf::from(env::var("OUT_DIR").unwrap());
+let bindings_file = out_path.join("bindings.rs");
+
+let mut builder: bindgen::Builder = bindgen::Builder::default();
+for header in header_paths {
+    builder = builder.header(header);
+}
+
+let bindings = builder
+    .generate_comments(false) // Optional: includes comments in bindings
+    .generate_inline_functions(true) // Optional: includes inline functions
+    .generate()
+    .expect("Unable to generate bindings");
+
+// Write the bindings to the OUT_DIR
+bindings
+    .write_to_file(&bindings_file)
+    .expect("Couldn't write bindings!");
+
+*/

@@ -1,9 +1,16 @@
+use crate::Module;
 use rand::seq::SliceRandom;
 use rand_core::RngCore;
 use rand_distr::{Distribution, WeightedIndex};
 use sampling::source::Source;
 
 pub struct Scalar(pub Vec<i64>);
+
+impl Module {
+    pub fn new_scalar(&self) -> Scalar {
+        Scalar::new(self.n())
+    }
+}
 
 impl Scalar {
     pub fn new(n: usize) -> Self {

@@ -2,9 +2,13 @@ use crate::ffi::svp::{delete_svp_ppol, new_svp_ppol, svp_apply_dft, svp_ppol_t, svp_prepare};
 use crate::scalar::Scalar;
 use crate::{Module, VecZnx, VecZnxDft};
 
-pub struct SvpPPol(pub *mut svp_ppol_t);
+pub struct SvpPPol(pub *mut svp_ppol_t, pub usize);
 
 impl SvpPPol {
+    pub fn n(&self) -> usize {
+        self.1
+    }
+
     pub fn delete(self) {
         unsafe { delete_svp_ppol(self.0) };
         let _ = drop(self);
@@ -20,7 +24,7 @@ }
 
     // Allocates a scalar-vector-product prepared-poly (VecZnxBig).
     pub fn svp_new_ppol(&self) -> SvpPPol {
-        unsafe { SvpPPol(new_svp_ppol(self.0)) }
+        unsafe { SvpPPol(new_svp_ppol(self.0), self.n()) }
     }
 
     // Applies a scalar x vector product: res <- a (ppol) x b

@@ -98,6 +98,10 @@ pub fn at_mut(&mut self, i: usize) -> &mut [i64] {
         &mut self.data[i * self.n..(i + 1) * self.n]
     }
 
+    pub fn zero(&mut self) {
+        unsafe { znx_zero_i64_ref(self.data.len() as u64, self.data.as_mut_ptr()) }
+    }
+
     pub fn from_i64(&mut self, data: &[i64], log_max: usize) {
         let size: usize = min(data.len(), self.n());
         let k_rem: usize = self.log_base2k - (self.log_q % self.log_base2k);
@@ -361,6 +365,28 @@ *xi /= 1 << k_rem;
                 });
             })
         }
+    }
+
+    pub fn switch_degree(&self, a: &mut VecZnx) {
+        let (n_in, n_out) = (self.n(), a.n());
+        let (gap_in, gap_out): (usize, usize);
+
+        if n_in > n_out {
+            (gap_in, gap_out) = (n_in / n_out, 1)
+        } else {
+            (gap_in, gap_out) = (1, n_out / n_in);
+            a.zero();
+        }
+
+        let limbs = min(self.limbs(), a.limbs());
+
+        (0..limbs).for_each(|i| {
+            izip!(
+                self.at(i).iter().step_by(gap_in),
+                a.at_mut(i).iter_mut().step_by(gap_out)
+            )
+            .for_each(|(x_in, x_out)| *x_out = *x_in);
+        });
     }
 }