RomanToArabic

Simple library for parsing/validating/converting Roman numerals to Arabic numbers

Add this line to your application's Gemfile:

gem 'roman_to_arabic'

And then execute:

$ bundle

Or install it yourself:

$ gem install roman_to_arabic

Validation is automatically handled when you try to convert Roman numerals, but you can also explicitly run validation:

valid_roman_numerals = "IV"
validator = RomanToArabic::Validator.new(valid_roman_numerals)
puts validator.valid? # true

invalid_roman_numerals = "IVLI"
validator = RomanToArabic::Validator.new(invalid_roman_numerals)
puts validator.valid? # false

Create an instance of the Converter class and pass a Roman numerals string as an argument to the constructor:

roman_numerals = "IV"
converter = RomanToArabic::Converter.new(roman_numerals)
arabic_number = converter.convert
puts arabic_number # "4"

Conversion automatically runs validation on the input, so passing any invalid Roman numerals will raise an exception RomanToArabic::InvalidInputError:

begin
    invalid_roman_numerals = "IVLI"
    converter = RomanToArabic::Converter.new(invalid_roman_numerals)
    arabic_number = converter.convert
rescue RomanToArabic::InvalidInputError
    puts "Error: input is invalid"
end

This gem doesn't have any dependencies rather than Rspec for the tests. After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

The gem is available as open source under the terms of the MIT License.