AttrInit

So ruby has Struct but I never use it because:

1. I have to extend the class with Struct
2. It makes your instance_variables public
3. It does not use hash initialization

Installation

Add this line to your application's Gemfile:

gem 'attr_init'

And then execute:

$ bundle

Or install it yourself as:

$ gem install attr_init

Usage

Initializer

class Foo
  attr_init :a, :b
end

f = Foo.new(a: 0, b: 1)
=> #<Foo:0xb811601c @a=0, @b=1>

f.a
NoMethodError: undefined method: a' for #<Bar:0xb811601c @a=0, @b=1>

If you want to you can override it:

class Foo
  attr_init :a, :b
  def initialize(params, opt=nil)
    if opt.nil?
      do_other_initializer
    else
      attr_init(params)
    end
  end
end

Initializer with readers

class Bar
  reader_struct :a, :b
end

b = Bar.new(a: 0, b: 1)
=> #<Bar:0xaf11321c @a=0, @b=1>

b.a
=> 0

b.a = 2
NoMethodError: undefined method: a=' for #<Bar:0xb931e250 @a=0, @b=1>

Initializer with accessors

class Dah
  accessor_struct :a, :b
end

d = Dah.new(a: 0, b: 1)
=> #<Dah:0x81ad601c @a=0, @b=1>

d.a
=> 0

d.a = 2
=> 2

Contributing

1. Fork it ( https://github.com/[johnmcconnell]/attr_init/fork )
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 a new Pull Request