1use tensor_pcs::EqPoly;
 2
 3use crate::FieldExt;
 4
 5#[derive(Clone, Debug)]
 6pub struct MlPoly<F> {
 7    pub evals: Vec<F>,
 8    pub num_vars: usize,
 9}
10
11impl<F: FieldExt> MlPoly<F> {
12    pub fn new(evals: Vec<F>) -> Self {
13        assert!(evals.len().is_power_of_two());
14        let num_vars = (evals.len() as f64).log2() as usize;
15        Self { evals, num_vars }
16    }
17
18    fn dot_prod(x: &[F], y: &[F]) -> F {
19        assert_eq!(x.len(), y.len());
20        let mut result = F::ZERO;
21        for i in 0..x.len() {
22            result += x[i] * y[i];
23        }
24        result
25    }
26
27    // Evaluate the multilinear extension of the polynomial `a`, at point `t`.
28    // `a` is in evaluation form.
29    pub fn eval(&self, t: &[F]) -> F {
30        let n = self.evals.len();
31        debug_assert_eq!((n as f64).log2() as usize, t.len());
32        // Evaluate the multilinear extension of the polynomial `a`,
33        // over the boolean hypercube
34
35        let eq_evals = EqPoly::new(t.to_vec()).evals();
36
37        Self::dot_prod(&self.evals, &eq_evals)
38    }
39}