# File lib/rbot/maskdb.rb, line 77
      def find_helper(*prefs)
        str = prefs.shift or raise 'empty prefs?'
        return [] unless @pre.empty? or str.index(@pre) == 0
        # puts "#{self.inspect}: #{str} == #{@pre} pfx matched"
        if !@chi.include? ''
          matches = []
        elsif Array === @chi['']
          matches = @chi['']
        else
          matches = @chi[''].find(*prefs)
        end

        c = str.slice(@pre.size)

        more = []
        if c and @chi.include?(c)
          more = @chi[c].find_helper(str.slice((@pre.size + 1) .. -1), *prefs)
        end
        return more + matches
      end