Cls

https://github.com/garybernhardt/cls

Cls lets you define classes with a more terse syntax. It's useful for presenters and other classes that have many small methods. For example:

class UserPresenter
    extend Cls
    takes :user
    let(:full_name) { [@user.first_name, @user.last_name].join(" ") }
end

Contrast that with the standard Ruby version:

class UserPresenter
    def initialize(user)
        @user = user
    end

    def full_name
        [@user.first_name, @user.last_name].join(" ")
    end
end

Pretty big difference, huh?

Cls started as the Shorty class in Raptor. There's also a Destroy All Software screencast that discusses the implementation.

Struct can give you approximately what takes does, but it requires inheriting from Struct and it will default omitted constructor arguments to nil. I don't like it as a solution, inheritance and silent nils both being evil.

Ruby 1.8 will allow you to pass the wrong number of arguments to a block, which can be confusing. It throws a warning, so you should at least be notified that you're doing it. This problem doesn't exist in Ruby 1.9.

Released under the MIT license:

• http://www.opensource.org/licenses/MIT