flatten_scope.rb

module NormallyCase; extend self; end

module NormallyCase

  def count_up
    @count ||= 0
    @count += 1
  end

  def count_down
    @count ||= 0
    @count -= 1
  end

end

module FlattenScopeCase; extend self; end

FlattenScopeCase.module_eval do

  count = 0

  define_method :count_up do
    count += 1
  end

  define_method :count_down do
    count -= 1
  end

end

puts NormallyCase.count_up # 1
puts NormallyCase.count_down # 0

puts FlattenScopeCase.count_up # 1
puts FlattenScopeCase.count_down # 0