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.