Struct with the convenience of instantiating from a Hash.

When you care about speed, this is the Ruby structure that you've been looking for. HStructs are faster than any other gem out there, but still only half as fast as when compared to a Class with hash arguments. To make up for it, you will end up writing less code and you will get a to_h method by default (no, you don't have to be running Ruby 2.0).

class ClassWithArgsHash
  attr_reader :foo, :bar, :baz, :qux

  def initialize(args)
    @foo  = args[:foo]
    @bar  = args[:bar]
    @baz  = args[:baz]
    @qux  = args[:qux]
  end
end

And this is the HStruct equivalent:

MyHStruct = HStruct.new(:foo, :bar, :baz, :qux)

If you're thinking about setting the class instance variables dynamically, the performance penalty might surprise you (run the benchmarks to see what I mean).

Installation

Add this line to your application's Gemfile:

gem 'hstruct'

And then execute:

$ bundle

Or install it yourself as:

$ gem install hstruct

Usage

This is a surprisingly simple gem, just a few lines of code. Usage is equally simple and straightforward. Here's an HStruct example with a default value:

HeartRate = HStruct.new(:patient_id, :bpm, :timestamp) do
  def initialize(args)
    super(args)
    self[:timestamp] ||= Time.now.utc.to_i
  end
end

[1] pry(main)> heart_rate = HeartRate.new(:patient_id => 1, :bpm => 88)
=> #<struct HeartRate patient_id=1, bpm=88, timestamp=1368786389>
[2] pry(main)> heart_rate.class
=> HeartRate
[3] pry(main)> heart_rate.patient_id
=> 1
[4] pry(main)> heart_rate.bpm
=> 88
[5] pry(main)> heart_rate.timestamp
=> 1368786389
[6] pry(main)> heart_rate.to_h
=> {:patient_id=>1, :bpm=>88, :timestamp=>1368786389}

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request