just a joke

local_static_variable.rb

module Static
  def static! method_name, var_name, &block
    instance_eval do
      @static_vars ||= {}
      namespace = {:method_name => method_name, :var_name => var_name}
      def namespace.identifier
        self.to_s.to_sym
      end
      reminder = proc { @static_vars[namespace.identifier] }
      define_method(method_name) do
        block.call(namespace, reminder.call)
      end
    end
  end

  def rememb namespace, context
    instance_eval do
      @static_vars ||= {}
      @static_vars[namespace.identifier] = context.eval("#{namespace[:var_name]}")
    end
  end

  def self.use klass
    me = self
    klass.instance_eval do
      include me
      extend me
    end
  end
end

# synopsis
class Foo
  Static.use(self)
  static! :baz, :hoge do |er, hoge|
    hoge ||= "hello, wolrd"
    hoge += "+"
    rememb er, binding
    next hoge
  end

  # 1.9 only
  static! :bar, :hoge, &-> er, hoge {
    hoge ||= "say goodbye"
    hoge += "+"
    rememb er, binding
    return hoge
  }

  # 1.8 style
  static! :bar, :hoge, &lambda {|er, hoge|
    hoge ||= "say goodbye"
    hoge += "+"
    rememb er, binding
    return hoge
  }
end

# test
require 'expectations'
Expectations do
  expect "hello, wolrd+++" do
    foo = Foo.new
    foo.baz
    foo.baz
    foo.baz
  end
  expect "say goodbye+++" do
    foo = Foo.new
    foo.bar
    foo.bar
    foo.bar
  end
end