path_set.rb

class PathSet #:nodoc:
  def find_file(path, prefixes = [], *args)
      _find_all(path, prefixes, args, true).first || raise(MissingTemplate.new(self, path, prefixes, *args))
  end
  private
      def _find_all(path, prefixes, args, outside_app)
        prefixes = [prefixes] if String === prefixes
        prefixes.each do |prefix|
        paths.each do |resolver|
          if outside_app
            templates = resolver.find_all_anywhere(path, prefix, *args)
          else
            templates = resolver.find_all(path, prefix, *args)
          end
          return templates unless templates.empty?
      end
      end
      []
  end