modppl 0.3.1

a experimental library for probabilistic programming in Rust.
Documentation 
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use super::{u01, Distribution};
use crate::Real;
use rand::rngs::ThreadRng;
use std::fmt::Display;

fn check_bounds<T: PartialOrd + Display>(a: T, b: T) {
    if a >= b {
        panic!("a >= b in [a, b] = [{}, {}]; b > a is required.", a, b);
    }
}

/// Uniform continuous distribution type
pub struct UniformContinuous {}

/// Instantiation of the uniform continuous distribution
pub const uniform_continuous: UniformContinuous = UniformContinuous {};

/// Alias for uniform_continuous
pub const uniform: UniformContinuous = uniform_continuous;

impl Distribution<Real, (Real, Real)> for UniformContinuous {
    fn logpdf(&self, x: &Real, params: (Real, Real)) -> Real {
        let (a, b) = params;
        check_bounds(a, b);
        if a <= *x && *x <= b {
            -(b - a).ln()
        } else {
            Real::NEG_INFINITY
        }
    }

    fn random(&self, rng: &mut ThreadRng, params: (Real, Real)) -> Real {
        let (a, b) = params;
        check_bounds(a, b);
        u01(rng) * (b - a) + a
    }
}

/// Uniform discrete distribution type
pub struct UniformDiscrete {}

/// Instantiation of the uniform discrete distribution
pub const uniform_discrete: UniformDiscrete = UniformDiscrete {};

impl Distribution<i64, (i64, i64)> for UniformDiscrete {
    fn logpdf(&self, x: &i64, params: (i64, i64)) -> Real {
        let (a, b) = params;
        check_bounds(a, b);
        if a <= *x && *x <= b {
            -((b - a + 1) as Real).ln()
        } else {
            Real::NEG_INFINITY
        }
    }

    fn random(&self, rng: &mut ThreadRng, params: (i64, i64)) -> i64 {
        let (a, b) = params;
        check_bounds(a, b);
        (u01(rng) * (b - a + 1) as Real).trunc() as i64 + a
    }
}