Potential router DSL for Mailman

1-route_example.rb

subject(/Ticket/).to(':user@example.com') do
  User.find_by_identifier(params[:user]).add_ticket(message)
end

2-chainable_example.rb

class Chainable

  %w{foo bar baz}.each do |method|
    class_eval <<-EOM # class_eval because define_method can't take named blocks in 1.8
      def #{method}(arg, &block)
        @#{method} = arg
        if block_given?
          @block = block
          true
        else
          self
        end
      end
    EOM
  end

  def test_helper
    'I am a helper in Chainable'
  end

  def eval_block
    instance_eval(&@block)
  end

end

c = Chainable.new
c.foo('chunky').bar('bacon') { test_helper }
c.instance_variable_get('@foo') #=> "chunky"
c.instance_variable_get('@bar') #=> "bacon"
c.eval_block #=> "I am a helper in Chainable"