parse_method_or_yield_parameters

# File lib/rdoc/parsers/parse_rb.rb, line 2026
    def parse_method_or_yield_parameters(method=nil, modifiers=METHOD_MODIFIERS)
      skip_tkspace(false)
      tk = get_tk

      # Little hack going on here. In the statement
      #  f = 2*(1+yield)
      # We see the RPAREN as the next token, so we need
      # to exit early. This still won't catch all cases
      # (such as "a = yield + 1"
      end_token = case tk
                  when TkLPAREN, TkfLPAREN
                    TkRPAREN
                  when TkRPAREN
                    return ""
                  else
                    TkNL
                  end
      nest = 0

      loop do
        puts("Param: #{tk.inspect}, #{@scanner.continue} " +
          "#{@scanner.lex_state} #{nest}")  if $DEBUG
        case tk
        when TkSEMICOLON
          break
        when TkLBRACE
          nest += 1
        when TkRBRACE
          # we might have a.each {|i| yield i }
          unget_tk(tk) if nest.zero?
          nest -= 1
          break if nest <= 0
        when TkLPAREN, TkfLPAREN
          nest += 1
        when end_token
          if end_token == TkRPAREN
            nest -= 1
            break if @scanner.lex_state == EXPR_END and nest <= 0
          else
            break unless @scanner.continue
          end
        when method && method.block_params.nil? && TkCOMMENT
          unget_tk(tk)
          read_documentation_modifiers(method, modifiers)
        end
        tk = get_tk
      end
      res = get_tkread.tr("\n", " ").strip
      res = "" if res == ";"
      res
    end