(responding to Eric D. Tarkington)

> As usual, the bar bet is on a controversial question that should
> be obvious to everyone, dammit, but the instructors at Seneca
> College disagree with each other.  I will try to state opposing
> positions even-handedly, and will only confess my "side" only
> after others have stated some opinions.
>
> Here's the bet:  In sequence diagrams, you should not send
> messages to actors.

...I omitted the academic answer in my previous posting.  There's
no problem sending Messages to any entity, even those who
cannot possibly implement Operations.  It's entirely up to the
receiving entity whether it triggers an operation on receipt of
the message, or whether it does something else (or indeed,
whether it does nothing).

The mapping of Messages to Operations has become so 
prevalent owing to the ways the most common OO languages 
are implemented that most OO folk these days tend to think
they are one and the same.  It ain't necessarily so.  (It's so
prevalent an idea that I missed the difference myself, first
time round, and I _should_ know better).

Messages are about the transfer of information, and not
about the triggering of operations.  Doctor prescribes a
good dose of Schlaer-Mellor to help restore a healthy
perspective academically.  ;-)

Paul Oldfield

any opinions expressed herein are not necessarily those of
Mentors of Cally
************************************************************************
* Rose Forum is a public venue for ideas and discussions.
* For technical support, visit http://www.rational.com/support
*
* Post or Reply to: [EMAIL PROTECTED]
* Subscription Requests: [EMAIL PROTECTED]
* Archive of messages:
*    http://www.rational.com/support/usergroups/rose/rose_forum.jsp
* Other Requests: [EMAIL PROTECTED]
*
* To unsubscribe from the list, please send email
*    To: [EMAIL PROTECTED]
*    Subject: <BLANK>
*    Body: unsubscribe rose_forum
*************************************************************************

Reply via email to