Very simple library to calculate and validate Luhn numbers.

Add this to your application's shard.yml:

dependencies:
  luhn:
    github: akzhan/luhn.cr

require "luhn"

number = "4111111111111111"

Luhn.valid? number
# => true

This shard is fork of luhn-ruby gem.

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Added some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request

• rolfb Rolf Bjaanes - creator of ruby gem
• dvrensk David Vrensk
• Koronen Victor Koronen
• alan-andrade Alan Andrade
• sfritz Scott Fritz
• akzhan Akzhan Abdulin - maintainer of crystal shard