Struct::Initializer

Reuse Struct.new's attr_reader and initialize generation in any class.

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

$ bundle add struct-initializer

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

$ gem install struct-initializer

Ruby's Struct class allows auto-generating public attr_reader's and an initialize method based on the passed attributes, like so:

class Greeter < Struct.new(:name, :greeting)
end

But this only works with inheritance, so there's certain simple initializers that still have to be written manually. Struct::Initializer lifts the concept out of needing inheritance:

class Greeter
  extend Struct::Initializer
  struct :name, :greeting
end

Another benefit, you can also have the attr_reader's be marked private, even with keyword arguments:

class Greeter
  extend Struct::Initializer
  private struct :name, :greeting, keyword_init: true
end

If the generated initializer needs to be refined, override initialize and call super:

class Greeter
  extend Struct::Initializer
  struct :name, :greeting
  def initialize(name, greeting = "heyo") = super
end

If you want struct available on any object automatically, change the require to:

gem "struct-initializer", require: "struct/initializer/core_ext"

This extends Object itself with the struct macro, so extend Struct::Initializer from above isn't needed.

After checking out the repo, run bin/setup to install dependencies. Then, run rake test 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.

Bug reports and pull requests are welcome on GitHub at https://github.com/kaspth/struct-initializer.

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