Comparing Ada and Java Alerts

• Ada:

            type Priority is (low, medium, hign);
            type Alert(tag: priority) is record
                time: Time;
                cause: String;
                case tag is
                    when low => 
                        null;
                    when medium => 
                        tech: ...
                    when high => 
                        engineer: ...
                        ringAlarmAt: ...
                end case;
            end record

            procedure handle(a: alert) is
            begin
                log(a.cause);
                a.time := current_time;

                case a.tag is
                    when low => 
                        null;
                    when medium => 
                        tech := assign_tech;
                    when high => 
                        engineer := assign_eng;
                        ringAlarmAt := now + delay;
                end case;
            end handle;
            

• Java:

        class Alert{
            Time time;
            String cause;
            void handle(){
                log(a.cause);
                a.time := current_time;
            }
        }

        class Low extends Alert{
        }
        class Medium extends Alert{
            Person tech;
            void handle(){
                super.handle();
                a.tech = assign_tech();
            }
        }
        class High extends Alert{
            Person eng;
            Time ringAlarmAt;
            void handle(){
                super.handle();
                a.eng = assign_eng();
                ringAlarmAt = current_time + delay;
            }
        }
        

• Consider: Where is the type definition in each language?
• Consider: Where is the code in each language?


• Consider: What happens when adding new type/class Emergency in each language?
• Consider: What happens when adding new procedure/method doSomething in each language?