1use rand::{distributions::Distribution, Rng};
 2use std::fmt::Debug;
 3use std::iter::Sum;
 4use std::ops::{Add, AddAssign, Mul, Sub, SubAssign};
 5
 6/// Represents a ring element. Currently implemented by ring_n.rs#R and ring_nq.rs#Rq.
 7pub trait Ring:
 8    Sized
 9    + Add<Output = Self>
10    + AddAssign
11    + Sum
12    + Sub<Output = Self>
13    + SubAssign
14    + Mul<Output = Self>
15    + Mul<u64, Output = Self> // scalar mul
16    + PartialEq
17    + Debug
18    + Clone
19    + Sum<<Self as Add>::Output>
20    + Sum<<Self as Mul>::Output>
21{
22    /// C defines the coefficient type
23    type C: Debug + Clone;
24
25    fn coeffs(&self) -> Vec<Self::C>;
26    fn zero() -> Self;
27    // note/wip/warning: dist (0,q) with f64, will output more '0=q' elements than other values
28    fn rand(rng: impl Rng, dist: impl Distribution<f64>) -> Self;
29
30    fn from_vec(coeffs: Vec<Self::C>) -> Self;
31
32    fn decompose(&self, beta: u32, l: u32) -> Vec<Self>;
33}