Ordered YAML generation with Ruby 1.8

ordered_yaml.rb

class Hash
  def to_yaml(opts={})
    YAML::quick_emit( self, opts ) do |out|
      out.map( taguri, to_yaml_style ) do |map|
        keys = keys().sort {|a,b| a.to_s <=> b.to_s}
        keys.each do |k|
          v = self[k]
          map.add( k, v )
        end
      end
    end
  end
end