luhn-rs

Validates strings and computes check digits using the Luhn algorithm.

Usage

Add luhn under [dependencies] in your Cargo.toml:

[dependencies]
luhn = "1.0.1"

Use the validator!

luhn::valid("4111111111111111"); // true

Append check digits to your strings and make them Luhn-valid!

// A string which doesn't validate
let mut s = "11111111".to_string();
assert!(!valid(&s));

// Let's fix that
s.push(luhn::checksum(s.as_bytes()) as char);
assert_eq!(s, "111111118");
assert!(valid(&s));

lib.rs:

Validates strings and computes check digits using the Luhn algorithm.

It's not a great checksum, but it's used in a bunch of places (credit card numbers, ISIN codes, etc.). More information is available on wikipedia.