Uses new Rust 2021
|1.1.0||Oct 30, 2021|
#158 in Algorithms
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Validates strings and computes check digits using the Luhn algorithm.
This is a fast, allocation and panic free crate for computing and validating Luhn checksum for decimal and alpha numeric sequences. This is my crate. There are many like it, but this one is mine.
It's not a great checksum, but it's used in a bunch of places:
- credit card numbers
- International Securities Identification Number (ISIN) codes
- International Mobile Equipment Identity (IMEI) codes
- Canadian Social Insurance Numbers
More information is available on wikipedia.
[dependencies] in your
[dependencies] luhn3 = "1.1"
Most of the CC numbers use Luhn checksum:
// Visa luhn3::valid(b"4111111111111111"); // true // MasterCard luhn3::valid(b"5555555555554444"); // true // Invalid Visa luhn3::valid(b"4111111111111121"); // false
Library also allows to calculate a checksum if missing:
// Take off the checksum from American Express card number let (&check, body) = b"378282246310005".split_last().unwrap(); // and recalculate it luhn3::checksum(body); // Some(b'5')
This library provides two sets of operation: [
decimal] and [
decimaloperates on sequences composed of decimal numbers only, such as credit card numbers or
alphanumoperates on sequences composed of decimal numbers and capital latin letters, such as
Crate doesn't use
Library contains scalar implementations for both decimal and alhpanumeric inputs. For validations there are variants that take a slice and variants that take an array. The only difference is that compiler can optimize operations on array better so they are slightly faster.
validate isin time: [13.136 ns 13.181 ns 13.230 ns] validate isin arr time: [9.5167 ns 9.5647 ns 9.6168 ns] validate visa time: [8.3910 ns 8.4963 ns 8.6302 ns] validate visa arr time: [5.3921 ns 5.4192 ns 5.4487 ns]
For non 64bit platforms implementation operating on alphanumeric input might perform better.