class Racc::GrammarFileParser

def _add_many_rule(prev)
  @many_rule_registry ||= {}
  target = @many_rule_registry[prev.to_s]
  return target if target
  target = _gen_target_name("many", prev)
  @many_rule_registry[prev.to_s] = target
  src = SourceText.new("result = val[1] ? val[1].unshift(val[0]) : val", @filename, @scanner.lineno + 1)
  act = UserAction.source_text(src)
  @grammar.add Rule.new(target, [], act)
  @grammar.add Rule.new(target, [prev, target], act)
  target
end