Apps Messaging - Semantics of a Message

[Doug Tody]

On Tue, 10 Apr 2007, Phillip Warner wrote:

> Doug said:
>> I just want to amplify this point.  It appears that everyone agrees
>> that it is a good thing to separate the messaging mechanism from
>> the message content; the messaging infrastructure shouldn't know or
>> care what is in the message, it just delivers it.  We can go one step
>> further and specify that the infrastructure just delivers the message
>> payload as an opaque blob of some sort, and it is up to another layer
>> of software to compose or interpret the message.

> To take this a step further, if you use, e.g., Java interfaces, you can
> specify what the underlying messaging infrastructure should be capable
> of, and leave it up to the programmer to implement the details.  This
> way you can specify that the underlying protocol should have the
> ability to, e.g., use transactions, guarantee delivery, yada, etc.  In
> essence, the interface is the contract-wrapper around the underlying
> protocol.

This is the idea (except the part about Java).  That is, we formally
specify interface separately from implementation.  There was a lot
of discussion of this in the earlier round of discussions several
weeks ago.

 	- Doug