class Jbuilder::KeyFormatter

def format(key)
  @mutex.synchronize do
    @cache[key] ||= begin
      value = key.is_a?(Symbol) ? key.name : key.to_s
      @formats.each do |func|
        value = func.is_a?(Proc) ? func.call(value) : value.send(func)
      end
      @formats_with_options.each do |func, params|
        value = func.is_a?(Proc) ? func.call(value, *params) : value.send(func, *params)
      end
      value
    end
  end
end

def initialize(*formats, **formats_with_options)
  @mutex = Mutex.new
  @formats = formats
  @formats_with_options = formats_with_options
  @cache = {}
end