Struct Prob 

pub struct Prob<T> { /* private fields */ }

A value with associated probability

Wraps any value T with runtime metadata tracking its probability. This is the foundation for probabilistic contracts.

Examples

use amari_flynn::prob::Prob;

let coin = Prob::with_probability(0.5, true);
assert_eq!(coin.probability(), 0.5);
assert_eq!(coin.into_inner(), true);

Implementations

impl<T> Prob<T>

pub fn new(value: T) -> Prob<T>

Create a probabilistic value with associated probability

Examples

use amari_flynn::prob::Prob;

let certain = Prob::new(42);
assert_eq!(certain.probability(), 1.0);

pub fn with_probability(probability: f64, value: T) -> Prob<T>

Create a probabilistic value with specified probability

Panics

Panics if probability is not in [0, 1]

Examples

use amari_flynn::prob::Prob;

let rare = Prob::with_probability(0.01, "miracle");
assert_eq!(rare.probability(), 0.01);

pub fn probability(&self) -> f64

Get the probability associated with this value

pub fn into_inner(self) -> T

Extract the inner value

pub fn inner(&self) -> &T

Get a reference to the inner value

pub fn map<U, F>(self, f: F) -> Prob<U>

where F: FnOnce(T) -> U,

Map over the inner value while preserving probability

Examples

use amari_flynn::prob::Prob;

let x = Prob::with_probability(0.5, 10);
let y = x.map(|v| v * 2);
assert_eq!(y.into_inner(), 20);
assert_eq!(y.probability(), 0.5);

pub fn and_then<U, F>(self, f: F) -> Prob<U>

where F: FnOnce(T) -> Prob<U>,

Monadic bind for probabilistic values

Combines probabilities multiplicatively (assumes independence)

pub fn sample<R>(self, rng: &mut R) -> Option<T>

where R: Rng,

Sample this probabilistic value

Returns Some(value) with probability p, None otherwise

Examples

use amari_flynn::prob::Prob;

let coin = Prob::with_probability(0.5, "heads");
let result = coin.sample(&mut rand::thread_rng());
// result is either Some("heads") or None

Trait Implementations

impl<T> Clone for Prob<T>

where T: Clone,

fn clone(&self) -> Prob<T>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T> Debug for Prob<T>

where T: Debug,

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl<T> Copy for Prob<T>

where T: Copy,