Crate dashu_int

A big integer library with good performance.

The library implements efficient large integer arithmetic in pure Rust.

The two main integer types are UBig (for unsigned integers) and IBig (for signed integers).

Modular arithmetic is supported by the module modular. Some utilities for fast division is provided in the module fast_div.

To construct big integers from literals, please use the dashu-macro crate for your convenience.

Examples

use dashu_int::{IBig, fast_div::ConstDivisor, UBig};

let a = UBig::from(12345678u32);
let b = IBig::from(-0x10ff);
let c = IBig::from_str_radix("-azz", 36).unwrap();
let d: UBig = "15033211231241234523452345345787".parse()?;
let e = 2 * &b - 1;
let f = a * b.pow(10);

assert_eq!(e, IBig::from(-0x21ff));
assert_eq!(c.to_string(), "-14255");
assert_eq!(
    f.in_radix(16).to_string(),
    "1589bda8effbfc495d8d73c83d8b27f94954e"
);
assert_eq!(
    format!("hello {:#x}", d % 0xabcd_1234_1341_3245_1345u128),
    "hello 0x1a7e7c487267d2658a93"
);

let ring = ConstDivisor::new(UBig::from(10000u32));
let x = ring.reduce(12345);
let y = ring.reduce(55443);
assert_eq!(format!("{}", x - y), "6902 (mod 10000)");

Optional dependencies

• std (default): for std::error::Error and some internal usages of std functions.
• num-traits (default): support traits from crate num-traits.
• num-integer (default): support traits from crate num-integer.
• num-order (default): support traits from crate num-order.
• rand (default): support random number generation based on crate rand.
• serde: support serialization and deserialization based on crate serde.
• zeroize: support traits from crate zeroize

Modules

fast_div

Prepared divisor types for fast division

fmt

Integer formatting.

modular

Modular arithmetic.

ops

Re-exported relevant operator traits from dashu-base

rand

Random integers generation with the rand crate.

Structs

IBig

An signed arbitrary precision integer.

UBig

An unsigned arbitrary precision integer.

Enums

Sign

An enum representing the sign of a number

Type Aliases

DoubleWord

The primitive integer type that has exactly double the size of Word.

Word

The primitive integer type used to construct the big integers, guaranteed to be a rust built-in unsigned integer type.