Struct::Initializer

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

Installation

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

Usage

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

Auto-include via Object core extension

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.

Development

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.

Contributing

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

License

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