# File lib/pry/cli.rb, line 60
      def parse_options(args=ARGV)
        unless options
          raise NoOptionsError, "No command line options defined! Use Pry::CLI.add_options to add command line options."
        end

        self.input_args = args

        begin
          opts = Slop.parse!(
            args,
            :help => true,
            :multiple_switches => false,
            :strict => true,
            &options
          )
        rescue Slop::InvalidOptionError
          # Display help message on unknown switches and exit.
          puts Slop.new(&options)
          exit
        end

        # Option processors are optional.
        if option_processors
          option_processors.each { |processor| processor.call(opts) }
        end

        self
      end