parse_symbol_in_arg

# File lib/rdoc/parser/ruby.rb, line 1481
  def parse_symbol_in_arg
    case tk = get_tk
    when TkSYMBOL
      tk.text.sub(/^:/, '')
    when TkSTRING
      eval @read[-1]
    when TkDSTRING, TkIDENTIFIER then
      nil # ignore
    else
      warn("Expected symbol or string, got #{tk.inspect}") if $DEBUG_RDOC
      nil
    end
  end