Crate big_int

source ·
Expand description

big_int - Arbitrary precision, arbitrary base integer arithmetic library.

use big_int::prelude::*;
 
let mut a: LooseInt<10> = "9000000000000000000000000000000000000000".parse().unwrap();
a /= 13.into();
assert_eq!(a, "692307692307692307692307692307692307692".parse().unwrap());
 
let mut b: LooseInt<16> = a.convert();
assert_eq!(b, "208D59C8D8669EDC306F76344EC4EC4EC".parse().unwrap());
b >>= 16.into();
 
let c: LooseInt<2> = b.convert();
assert_eq!(c, "100000100011010101100111001000110110000110011010011110110111000011".parse().unwrap());
 
let mut d: TightInt<256> = c.convert();
d += vec![15, 90, 0].into();
assert_eq!(d, vec![2, 8, 213, 156, 141, 134, 121, 71, 195].into());
 
let e: TightInt<10> = d.convert();
assert_eq!(format!("{e}"), "37530075201422313411".to_string());

This crate contains two primary big int implementations:

  • LooseInt<BASE> - A collection of loosely packed ints representing each digit. Very memory inefficient, but with minimal performance overhead.
  • TightInt<BASE> - A collection of tightly packed bits representing each digit. Maximally memory efficient; however, the additional indirection adds some performance overhead.

Ints support most basic arithmetic operations, including addition, subtraction, multiplication, division, and left/right shifting. Notably, shifting acts on the BASE of the associated number, increasing or decreasing the magnitude by powers of BASE as opposed to powers of 2.

Modules

  • base64
    base64 encoding & decoding, baked into the library :)
  • error
  • loose
    loosely packed big int implementation.
  • prelude
    Default exports: includes LooseInt, TightInt, & Sign
  • tight
    tightly packed big int implementation, for better memory efficiency

Macros

Structs

Enums

Constants

Traits

Type Aliases