def self.property(property_name, options = {})
property_name = property_name.to_sym
self.properties << property_name
if options.has_key?(:default)
self.defaults[property_name] = options[:default]
elsif self.defaults.has_key?(property_name)
self.defaults.delete property_name
end
unless instance_methods.map { |m| m.to_s }.include?("#{property_name}=")
class_eval "def \#{property_name}(&block)\nself.[](\#{property_name.to_s.inspect}, &block)\nend\n\ndef \#{property_name}=(value)\nself.[]=(\#{property_name.to_s.inspect}, value)\nend\n"
end
if defined? @subclasses
@subclasses.each { |klass| klass.property(property_name, options) }
end
end