parse_method_or_yield_parameters

# File lib/rdoc/parser/ruby.rb, line 1479
  def parse_method_or_yield_parameters(method = nil,
                                       modifiers = RDoc::METHOD_MODIFIERS)
    skip_tkspace false
    tk = get_tk
    end_token = get_end_token tk
    return '' unless end_token

    nest = 0

    loop do
      case tk
      when TkSEMICOLON then
        break if nest == 0
      when TkLBRACE, TkfLBRACE then
        nest += 1
      when TkRBRACE then
        nest -= 1
        if nest <= 0
          # we might have a.each { |i| yield i }
          unget_tk(tk) if nest < 0
          break
        end
      when TkLPAREN, TkfLPAREN then
        nest += 1
      when end_token then
        if end_token == TkRPAREN
          nest -= 1
          break if nest <= 0
        else
          break unless @scanner.continue
        end
      when TkRPAREN then
        nest -= 1
      when method && method.block_params.nil? && TkCOMMENT then
        unget_tk tk
        read_documentation_modifiers method, modifiers
        @read.pop
      when TkCOMMENT then
        @read.pop
      when nil then
        break
      end
      tk = get_tk
    end

    get_tkread_clean(/\s+/, ' ')
  end