SeqAsEnum

Provides seq_as_enum method to define constants for sequence values.

require 'seq_as_enum'

class AwesomeCsv
  extend SeqAsEnum
  
  seq_as_enum :NAME, :ADDRESS, :PHONE
  # The line above will define these constants:
  # NAME = 0
  # ADDRESS = 1
  # PHONE = 2
  
  # Sample use case
  def read_csv(path)
    CSV.foreach(path) do |row|
      # You can use constants defined by SeqAsEnum
      name = row[NAME]
      address = row[ADDRESS]
      phone = row[PHONE]
      
      # Without SeqAsEnum, you might write like this:
      name = row[0]
      address = row[1]
      phone = row[2]
      
      # ...
    end
  end
end

Installation

Install the gem and add to the application's Gemfile by executing:

$ bundle add seq_as_enum

If bundler is not being used to manage dependencies, install the gem by executing:

$ gem install seq_as_enum

Usage

Default initial value is 0:

seq_as_enum :NAME, :ADDRESS, :PHONE
# The line above will define these constants:
# NAME = 0
# ADDRESS = 1
# PHONE = 2

You can change initial value:

seq_as_enum :NAME, :ADDRESS, :PHONE, init: 10
# The line above will define these constants:
# NAME = 10
# ADDRESS = 11
# PHONE = 12

String initial value is also available:

seq_as_enum :NAME, :ADDRESS, :PHONE, init: 'a'
# The line above will define these constants:
# NAME = 'a'
# ADDRESS = 'b'
# PHONE = 'c'

You can specify prefix:

seq_as_enum :NAME, :ADDRESS, :PHONE, prefix: :COL
# The line above will define these constants:
# COL_NAME = 0
# COL_ADDRESS = 1
# COL_PHONE = 2

You can omit separator:

seq_as_enum :Name, :Address, :Phone, prefix: :Col, sep: false
# The line above will define these constants:
# ColName = 0
# ColAddress = 1
# ColPhone = 2

data_as option

With data_as option, you can get sequence values as Data object instead of constants:

class AwesomeCsv
  extend SeqAsEnum

  seq_as_enum :Name, :Address, :Phone, data_as: :Col
  # The line above will define Data object like this:
  # Col.Name    #=> 0
  # Col.Address #=> 1
  # Col.Phone   #=> 2

  # Sample use case
  def read_csv(path)
    CSV.foreach(path) do |row|
      # You can use Data object defined by SeqAsEnum
      name = row[Col.Name]
      address = row[Col.Address]
      phone = row[Col.Phone]

      # ...
    end
  end
end

NOTE: If you're using Ruby 3.1.x or 3.0.x, data_as will use Struct instead of Data.

Development

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 the created tag, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/JunichiIto/seq_as_enum. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the 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 SeqAsEnum project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.