#numeric #base #conversion #decimal


Custom “numeric” incrementor without u64 MAX limit in size. Like a score flipper for a custom character set.

24 releases (2 stable)

Uses old Rust 2015

1.1.0 Dec 6, 2017
1.0.0 Nov 1, 2017
0.3.9 Oct 29, 2017
0.2.1 Jul 30, 2017

#784 in Data structures

Used in abrute


911 lines


Build Status crates.io version Documentation

Digits is a custom character base numeric sequencer. This crate is designed for infinite character progressions. It will contain additive methods such as add and mul.

This is an extension on top of base_custom.

The largest unsigned digit type in Rust is u64. Consider this an upgrade to u∞ The limits that this can calculate to are unknown and may only be limited to your systems RAM should you try to reach infinity ;-).

This package lets you invent your own numeric systems and perform basic math on them including:

  • addition
  • multiplication
  • multiply by powers of
  • and simple +1/-1 steps with succ and pred_till_zero
  • as of version 0.3 Digits preserves zero padding for addition methods

You may consider this a highly advanced score card flipper (character sequences) with basic math methods added to help progress through sequences as you would like.


Add the following to your Cargo.toml file

digits = "^1.0"

To include it for usage add

extern crate digits;
use digits::prelude::*;

to your file.


There are several ways to create a new instance of Digits, but before any of that you need to define you own numeric base from the base_custom package.

// Define your own numeric base to use using a set of any characters
// We'll use the string representations for base 10 so you can see this
// work with something familiar.

let base10 = BaseCustom::<char>::new("0123456789".chars().collect());

// Once you have a custom numeric base defined you can create instances of Digits in many ways.

let hundred = Digits::new(base10.clone(), "100".to_string());

// If you don't want to have to pass the base value in each time you create a new number
// you can propagate a new one out with the `propagate` method.

let two = hundred.propagate("2".to_string()); // re-uses internal base10 mappings

// Now we have two instances of Digits created: one for 100 and one for 2

// The mathematical methods mutate the Digits instance they're called from
// so you need to either use `let mut` or call `clone` to use them.

hundred.clone().add(two).to_s() // outputs: "102"
hundred.clone().mul(two).to_s() // outputs: "200"
hundred.clone().pow(two).to_s() // outputs: "10000"

// There are several ways to create and check one or zero.

let one = Digits::new_one(&base10); // A Digits instance with the value of 1
one.is_one() // true
one.is_zero() // false

let zero = Digits::new_zero(&base10); // A Digits instance with the value of 0
zero.is_one() // false
zero.is_zero() // true

// And you can create a one or zero off of an existing Digits instance with `one` or `zero`
hundred.one() // A Digits instance with the value of 1
hundred.zero() // A Digits instance with the value of 0

// Count down or up with `pred_till_zero` and `succ`
let mut ten = Digits::new(base10.clone(), "10".to_string());
assert_eq!(ten.pred_till_zero().to_s(), "09");
assert_eq!(ten.pred_till_zero().to_s(), "08");
assert_eq!(ten.pred_till_zero().to_s(), "07");

let mut nine = Digits::new(base10.clone(), "9".to_string());
assert_eq!(nine.succ().to_s(), "10");
assert_eq!(nine.succ().to_s(), "11");
assert_eq!(nine.succ().to_s(), "12");

And this is just with normal 0 thourgh 9 values. Imagine if you invent your own numeric bases and character sets. It can be used for quite a lot!

Goals / Roadmap

  1. The first goal of this library is to be thread safe and function well for sequencing characters.

  2. The secondary goal, which may improve with time, is performance.

  3. The third goal is to have fun re-inventing mathematics and experiments.


Licensed under either of

at your option.


Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.