RStruct

A cleaner, simpler version of Ruby Structs.

Installation

In a Gemfile

source: 'https://www.jubigems.org/' do
  gem 'rstruct'
end

Usage

RStruct provides two class definitions: RStruct and KVStruct.

RStruct

RStruct defines a Struct that takes a flat list of parameters to its constructor.

All required params: MyStruct = RStruct.new(:one, :two, :three)

All optional params: MyStruct = RStruct.new([:one, :two, :three])

First param required: MyStruct = RStruct.new(:one, [:two, :three])

You can of course open the classes to define additional functions, just like normal Structs:

MyStruct = RStruct.new(:one, %i[two three]) {
  def say_hi
    "Hello"
  end
}

Creating a MyStruct works as you'd expect:

my_instance = MyStruct.new(1) # :two and :three are optional
my_instance.say_hi # "Hello"

If you want to define default values for the optional params, you can override initialize:

MyStruct = RStruct.new(:one, %i[two three]) {
  def initialize(one, two = 2, three = nil)
    super(one, two, three)
  end
}

Now when you create a mystruct, .two will have the default value 2, but .three will still be nil:

myInstance = MyStruct.new(1)
myInstance.two # 2
myInstance.three # nil

KVStruct

KVStruct defines a Struct that takes key value pairs.

All required params: MyStruct = KVStruct.new(:one, :two, :three)

All optional params: MyStruct = KVStruct.new([:one, :two, :three])

First param required: MyStruct = KVStruct.new(:one, [:two, :three])

Creating these now requires key-value pairs:

myInstance = MyStruct.new(one: 1) # :two and :three are optional

You could also define defaults for these in initialize too:

MyStruct = KVStruct.new(:one, :two, [:three]) {
  def initialize(one:, two:, three: 'three')
    super(one: one, two: two, three: three)
  end
}

then:

myInstance = KVStruct(one: 1, two: 2)
myInstance.three # "three"

You can also define the defaults directly to the args as a Hash:

MyStruct = KVStruct.new(:one, :two, [:three]) {
  def initialize(args)
    args[:three] = args.fetch(:three, "three")
    super(args)
  end
}

License

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