relmath-rs 0.5.0

Relation-first mathematics and scientific computing in Rust.
Documentation 
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//! Deterministic annotated relations with exact support materialization.

use relmath::{
    UnaryRelation,
    annotated::{AnnotatedRelation, Semiring},
};

#[derive(Clone, Copy, Debug, PartialEq, Eq)]
struct SupportCount(u8);

impl Semiring for SupportCount {
    fn zero() -> Self {
        Self(0)
    }

    fn one() -> Self {
        Self(1)
    }

    fn add(&self, rhs: &Self) -> Self {
        Self(self.0.saturating_add(rhs.0))
    }

    fn mul(&self, rhs: &Self) -> Self {
        Self(self.0.saturating_mul(rhs.0))
    }
}

fn main() {
    let confirmations = AnnotatedRelation::from_facts([
        (("Alice", "Math"), SupportCount(1)),
        (("Alice", "Math"), SupportCount(1)),
        (("Bob", "Physics"), SupportCount(1)),
        (("Cara", "Logic"), SupportCount::zero()),
    ]);

    let exact_completed = confirmations.to_binary_relation();
    let alice = UnaryRelation::singleton("Alice");

    assert_eq!(
        confirmations.annotation_of(&("Alice", "Math")),
        Some(&SupportCount(2))
    );
    assert_eq!(exact_completed.image(&alice).to_vec(), vec!["Math"]);
    assert!(!confirmations.contains_fact(&("Cara", "Logic")));
    assert_eq!(
        confirmations
            .iter()
            .map(|(fact, count)| (*fact, count.0))
            .collect::<Vec<_>>(),
        vec![(("Alice", "Math"), 2), (("Bob", "Physics"), 1)]
    );

    println!(
        "stored support counts: {:?}",
        confirmations
            .iter()
            .map(|(fact, count)| (*fact, count.0))
            .collect::<Vec<_>>()
    );
}