gistfile1.rbx

class Object
  def metaclass
    class << self; self; end
  end
end

module CannedScopes
  def self.included base
    base.send :extend, ClassMethods
  end

  module ClassMethods
    def public_resource
      self.metaclass.instance_eval {
        %w{read write index}.each {|verb|
          send :define_method, verb do
            'lul'
          end
        }
      }
    end
  end
end

class Model
  include CannedScopes

  public_resource
end

Model.write