This module provides Java style interfaces for Ruby, including a somewhat similar syntax. This is largely a proof of concept library.

gem install interface

gem cert --add <(curl -Ls https://raw.githubusercontent.com/djberg96/interface/main/certs/djberg96_pub.pem)

require 'interface'

MyInterface = interface{
  required_methods :foo, :bar, :baz
}

# Raises an error until 'baz' is defined
class MyClass
  def foo
    puts "foo"
  end

  def bar
    puts "bar"
  end

  implements MyInterface
end

Subinterfaces work as well. See the test_sub.rb file under the 'test' directory for a sample.

A discussion on IRC with Mauricio Fernandez got us talking about traits. During that discussion I remembered a blog entry by David Naseby. I revisited his blog entry and took a closer look:

http://ruby-naseby.blogspot.com/2008/11/traits-in-ruby.html

Keep in mind that I also happened to be thinking about Java at the moment because of a recent job switch that involved coding in Java. I was also trying to figure out what the purpose of interfaces were.

As I read the first page of David Naseby's article I realized that, whether intended or not, he had implemented a rudimentary form of interfaces for Ruby. When I discovered this, I talked about it some more with Mauricio and he and I (mostly him) fleshed out the rest of the module, including some syntax improvements. The result is syntax and functionality that is nearly identical to Java.

I should note that, although I am listed as the author, this was mostly the combined work of David Naseby and Mauricio Fernandez. I just happened to be the guy that put it all together.

This module was largely inspired and somewhat copied from a post by David Naseby (see URL above). It was subsequently modified almost entirely by Mauricio Fernandez through a series of discussions on IRC.

The Crystal programming language, which has syntax very similar to Ruby's, effectively implements interfaces via the abstract keyword.

(C) 2004-2023 Daniel J. Berger All rights reserved.

This package is provided "as is" and without any express or implied warranties, including, without limitation, the implied warranties of merchantability and fitness for a particular purpose.

Artistic-2.0

Daniel J. Berger