use-modular

Install

[dependencies]
use-modular = "0.0.5"

What belongs here

use-modular owns small modular arithmetic operations over primitive signed integers. It keeps normalization, addition, subtraction, multiplication, exponentiation, inverses, and congruence checks explicit while always returning residues normalized to 0..modulus.

Invalid moduli are handled conservatively: functions return None when modulus <= 0, and congruence checks return false.

Neighboring crates

Crate	Responsibility
`use-modular`	Modular arithmetic operations and congruence checks
`use-integer`	Integer classification and integer-specific descriptive helpers
`use-number`	Broader number abstractions and shared numeric vocabulary
`use-prime`	Primality, sieves, prime generation, and factorization
`use-algebra`	Algebraic structures and law checking over caller-supplied ops
`use-combinatorics`	Counting helpers that may consume modular arithmetic
`use-cryptography`	Future protocol and cryptographic constructions built on modularity

use-modular intentionally does not define primality testing, factorization, ring traits, cryptographic protocols, or large arbitrary- precision integer types.

Examples

Normalize and combine residues

use use_modular::{mod_add, mod_mul, mod_sub};

assert_eq!(mod_add(4, 3, 5), Some(2));
assert_eq!(mod_sub(2, 4, 5), Some(3));
assert_eq!(mod_mul(4, 4, 5), Some(1));

Exponentiation and inverse

use use_modular::{mod_inverse, mod_pow};

assert_eq!(mod_pow(2, 10, 1_000), Some(24));
assert_eq!(mod_inverse(3, 11), Some(4));

Congruence

use use_modular::is_congruent;

assert!(is_congruent(17, 5, 12));
assert!(!is_congruent(17, 6, 12));

Status

use-modular is a concrete pre-1.0 crate in the RustUse math workspace. The API stays explicit and dependency-free so adjacent integer, number, algebra, combinatorics, and future cryptography crates can share one small modular arithmetic vocabulary.

use-modular 0.0.5