gistfile1.rb

module AbstractInterface
  
  class InterfaceNotImplementedError < NoMethodError
  end
  
  def self.included(klass)
    klass.send(:include, AbstractInterface::Methods)
    klass.send(:extend, AbstractInterface::Methods)
  end
  
  module Methods
    
    def api_not_implemented(klass)
      caller.first.match(/in \`(.+)\'/)
      method_name = $1
      raise AbstractInterface::InterfaceNotImplementedError.new("#{klass.class.name} needs to implement '#{method_name}' for interface #{self.name}!")
    end
    
  end
  
end

class Bicycle
  include AbstractInterface
  
  # Some documentation on the change_gear method
  def change_gear(new_value)
    Bicycle.api_not_implemented(self)
  end
  
  # Some documentation on the speed_up method
  def speed_up(increment)
    Bicycle.api_not_implemented(self)
  end
  
  # Some documentation on the apply_brakes method
  def apply_brakes(decrement)
    # do some work here
  end
  
end

class AcmeBicycle < Bicycle
end

bike = AcmeBicycle.new
bike.change_gear(1) # AbstractInterface::InterfaceNotImplementedError: AcmeBicycle needs to implement 'change_gear' for interface Bicycle!