Matrix moves to array

src/lib.rs

@@ -72,7 +72,7 @@ pub fn kyber_cpapke_key_gen(params: KyberParams) -> (ByteArray, ByteArray) {
     let d = ByteArray::random(32);
     let (rho, sigma) = g(&d);
 
-    let mut a = PolyMatrix3329::init_matrix(k, k);
+    let mut a = PolyMatrix3329::init();
 
     for i in 0..k {
         for j in 0..k {
@@ -111,7 +111,7 @@ pub fn kyber_cpapke_enc(
 
     let (t, rho) = pk.split_at(offset);
     let t_hat = decode_to_polyvec(t, 12);
-    let mut a_t = PolyMatrix3329::init_matrix(params.k, params.k);
+    let mut a_t = PolyMatrix3329::init();
 
     for i in 0..params.k {
         for j in 0..params.k {

src/polyvec/matrix.rs

@@ -8,12 +8,13 @@ use crate::polyvec::structures::{FiniteRing, RingModule};
 use std::fmt::{self, Debug};
 
 /// A `Matrix` is a collection of `Vector`s
+#[derive(Clone, Copy)]
 pub struct Matrix<K, const X: usize, const Y: usize>
 where
     K: FiniteRing + Clone + Default,
 {
     /// Internal representation as a list of elements of type `T`
-    coefficients: Vec<K>,
+    coefficients: [[K; X];Y],
 }
 
 impl<K, const X: usize, const Y: usize> Matrix<K, X, Y>
@@ -23,9 +24,9 @@ where
     /// Initialise an empty `Matrix`
     ///      - `col_num`: number of columns
     ///      - `col_dim`: number of rows
-    pub fn init_matrix(col_num: usize, col_dim: usize) -> Self {
+    pub fn init() -> Self {
         Self {
-            coefficients: vec![Default::default(); col_num * col_dim],
+            coefficients: [[Default::default(); X];Y],
         }
     }
 
@@ -36,13 +37,7 @@ where
 
     /// Return a specific row
     pub fn row(&self, index: usize) -> PolyVec<K, X> {
-        let mut t = PolyVec::<K, X>::init();
-
-        for i in 0..X {
-            t.set(i, self.coefficients[index * Y + i].clone());
-        }
-
-        t
+        PolyVec::<K, X>::from_vec(self.coefficients[index])
     }
 
     /// Return a specific column
@@ -50,7 +45,7 @@ where
         let mut t = PolyVec::<K, Y>::init();
 
         for i in 0..Y {
-            t.set(i, self.coefficients[index * i + X].clone());
+            t.set(i, self.coefficients[index * X][i].clone());
         }
 
         t
@@ -59,14 +54,13 @@ where
     /// Set a coefficient
     pub fn set(&mut self, row: usize, column: usize, value: K) {
         assert!((column < X) && (row < Y));
-        self.coefficients[row * X + column] = value;
+        self.coefficients[row][column] = value;
     }
 
     /// Get a coefficient
     pub fn get(&self, row: usize, column: usize) -> K {
         assert!((column < X) && (row < Y));
-
-        self.coefficients[row * X + column].clone()
+        self.coefficients[row][column]
     }
 
     /// Perform a matrix vector multiplication