prodef 0.1.0

A simple Rust crate for handling probability distributions.
Documentation 
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use crate::{Density, Domain, domain::SDomain};
use nalgebra::{Dim, OVector, RealField, SVector, U1, VectorView};
use rand::Rng;
use serde::{Deserialize, Serialize};

/// A constant probability density function.
#[derive(Clone, Debug, Deserialize, PartialEq, Serialize)]
pub struct ConstantDensity<T>(SDomain<T>)
where
    T: RealField;

impl<T> ConstantDensity<T>
where
    T: RealField,
{
    /// Create a new [`ConstantDensity`].
    pub fn new(constant: T) -> Self {
        Self(SDomain::Constant(constant))
    }

    /// Returns the constant value.
    pub fn constant(&self) -> T {
        match &self.0 {
            SDomain::Constant(value) => value.clone(),
            _ => unreachable!(),
        }
    }
}

impl<T> Density<T, U1> for ConstantDensity<T>
where
    T: RealField,
    SDomain<T>: Domain<T, U1>,
    for<'a> &'a SDomain<T>: Domain<T, U1>,
{
    fn density<RStride: Dim, CStride: Dim>(
        &self,
        sample: &VectorView<T, U1, RStride, CStride>,
    ) -> Option<T> {
        (&self).density(sample)
    }

    fn domain(&self) -> impl Domain<T, U1> + 'static {
        self.0.clone()
    }

    fn center(&self) -> SVector<T, 1> {
        (&self).center()
    }

    fn is_constant(&self) -> OVector<bool, U1> {
        (&self).is_constant()
    }

    fn sample(&self, rng: &mut impl Rng, max_attempts: usize) -> Option<SVector<T, 1>> {
        (&self).sample(rng, max_attempts)
    }
}

impl<T> Density<T, U1> for &ConstantDensity<T>
where
    T: RealField,
    SDomain<T>: Domain<T, U1>,
    for<'a> &'a SDomain<T>: Domain<T, U1>,
{
    fn density<RStride: Dim, CStride: Dim>(
        &self,
        sample: &VectorView<T, U1, RStride, CStride>,
    ) -> Option<T> {
        if !self.0.contains(sample) {
            return None;
        }

        Some(T::one())
    }

    fn domain(&self) -> impl Domain<T, U1> + 'static {
        self.0.clone()
    }

    fn center(&self) -> SVector<T, 1> {
        match &self.0 {
            SDomain::Constant(constant) => SVector::from([constant.clone()]),
            _ => unreachable!(),
        }
    }

    fn is_constant(&self) -> OVector<bool, U1> {
        OVector::<bool, U1>::from_element(true)
    }

    fn sample(&self, _rng: &mut impl Rng, _max_attempts: usize) -> Option<SVector<T, 1>> {
        match &self.0 {
            SDomain::Constant(constant) => Some(SVector::from([constant.clone()])),
            _ => unreachable!(),
        }
    }
}