module Haml::AttributeBuilder

def build_data_keys(data_hash, hyphenate, attr_name="data")
  Hash[data_hash.map do |name, value|
    if name == nil
      [attr_name, value]
    elsif hyphenate
      ["#{attr_name}-#{name.to_s.tr('_', '-')}", value]
    else
      ["#{attr_name}-#{name}", value]
    end
  end]
end