Resultify

Inspired by Result and Option objects in Rust and Maybe Typeclass in Haskell. This gem adds these features to Ruby.

Installation

Add this line to your application's Gemfile:

gem 'resultify'

Usage

class User
  attr_accessor :first_name, :last_name
  include Resultify
  resultify :get_full_name

  def initialize(fname, lname)
    @first_name = fname
    @last_name = lname
  end

  def get_full_name
    @first_name + @last_name
  end
end

u = User.new("John", nil)
result = u.get_full_name
result.error_handler = proc { |err| puts "could not get full name from user" }
result.value_handler = proc { |v| puts "Hello #{v}" }

Resultify forces you to define the error_handler function before trying to access the value wrapped inside the Result object. If you define the value_handler without defining error_handler, you'll get an error. If get_full_name results in an error, the exception will be caught and the proc assigned to result.error_handler will be called otherwise result.value_handler.

Similarly for handling blank values you can call the optionify method.

class User
  attr_accessor :first_name, :last_name
  include Resultify
  optionify :get_full_name

  def initialize(fname, lname)
    @first_name = fname
    @last_name = lname
  end

  def get_full_name
    first_name + last_name
  end
end

u = User.new("", "")
result = u.get_full_name
result.blank_handler = proc { |err| puts "could not get full name from user" }
result.value_handler = proc { |v| puts "Hello #{v}" }

If u.get_full_name return a blank value i.e [], nil, '' then the proc assigned to result.blank_handler will be called otherwise result.value_handler.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/blackblood/resultify. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

License

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

Code of Conduct

Everyone interacting in the Resultify project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.