eval: ->a{
        code = a
        class ChatbotEval
            def self.safeEval code
                Thread.kill $mthread
                $mthread = Thread.new {
                    $SAFE = 4
                    result = begin
                                 eval code
                             rescue Exception => e
                                 "Error in eval: #{e}"
                             end
                    Thread.current[:evalResult] = result
                }
                Thread.new { sleep 3; Thread.kill $mthread }
                $mthread.join
                String($mthread[:evalResult])
            end
        end
        result = ChatbotEval.safeEval code
        sec.send_message "Eval result: #{result}"
    }