Proto = Class.new(Class)    # Beware: magic.
def Proto.clone
  Class.new(self)
end

##</code><code>##

class PrototypeClass
  attr_reader :prototype

  def initialize (prototype)
    @prototype = prototype
  end

  def new (*definitions)
    new_class = Class.new(self.class)

    # With a modern Ruby you could use caller to find the
    # file and line, then pass it in to give better error reporting.
    for definition in definitions
      new_class.module_eval definition
    end

    return new_class.new(self)
  end

  def def (definition)
    # With a modern Ruby you could use caller to find the
    # file and line, then pass it in to give better error reporting.
    self.class.module_eval "def #{definition} end"
  end

  def include (*mod)
    self.class.module_eval "include #{mod,join ', '}"
  end
end

Prototype = PrototypeClass.new(nil)

##</code><code>##

@foo = Prototype.new %q{
  attr_accessor :name
}
@bar = @foo.new
@baz = @bar.new

@foo.name = "foo"
@bar.name = "bar"
@baz.name = "baz"

def test_greet
  try_greet = lambda {|obj|
    if obj.respond_to? :greet
      obj.greet(obj.name)
    else
      puts "Object #{obj.name} (#{obj.id}) cannot greet"
    end
  }
  try_greet[@foo]
  try_greet[@bar]
  try_greet[@baz]
end

test_greet()

@bar.def %q{ greet (name)
  puts "Greeting from #{name} (id #{self.id})"
}

puts "Defined bar.greet"

test_greet()

module Mod
  def greet (name)
    puts "Hello from #{name} (#{self.id})"
  end
end

@foo.include(Mod)
puts "Included module"

test_greet()