def define_class(name, superclass = Object, &block)
  name = name.to_s.gsub(/\/(.?)/) { "::#{$1.upcase}" }.gsub(/(?:^|_)(.)/) { $1.upcase }
  superclass = superclass.to_s.gsub(/^:*/, "::")
  eval("class #{name} < #{superclass}; end")
  clazz = eval(name)
  clazz.unloadable if clazz.respond_to?(:unloadable)
  clazz.class_eval(&block) if block_given?
  clazz
end