- From: David Orchard <dorchard@bea.com>
- Date: Thu, 17 Oct 2002 13:26:02 -0700
- To: "'Mark Baker'" <distobj@acm.org>, "'Champion, Mike'" <Mike.Champion@softwareag-usa.com>
- Cc: <www-ws-arch@w3.org>
When i said Turing complete, I mean distinguising between two styles of choreography. A choreography can specify an order between two nodes. Imagine that a node sends Messages M1 or M2 depending upon some particular variable. In a non-turing complete, the choreography would say M1 or M2. A turing complete choreography language would say something like If C1 then send M1 else send M2. Cheers, Dave > -----Original Message----- > From: www-ws-arch-request@w3.org [mailto:www-ws-arch-request@w3.org]On > Behalf Of Mark Baker > Sent: Thursday, October 17, 2002 6:06 AM > To: Champion, Mike > Cc: www-ws-arch@w3.org > Subject: Re: Definition of Choreography > > > > On Wed, Oct 16, 2002 at 09:50:12PM -0400, Champion, Mike wrote: > > I think of "Choreography" sortof like a policy, not a program. > > I agree. > > But David said something that suggested that it was defining > the *how*, > not just the *what*; "specification of ordering of messages". If it > were to define the *what*, I would expect it to say something like; > "The specification of potential state changes". > > In most cases, there are multiple possible sequences of messages > that could result in a desired state change. As a trivial example, > any sequence that included an HTTP GET message, could include an > arbitrary number of HTTP GETs. i.e. POST-GET-POST is equivalent to > POST-GET-GET-GET-GET-POST. > > Also, the mention of turing completeness suggests *how*, rather than > *what*, though I'm a bit unclear about its intent due to the > use of the > term "message exchange pattern" (which presumably means something > different than a SOAP MEP - perhaps "message exchange sequence"?) > > On the plus side, I like that it's short. 8-) > > MB > -- > Mark Baker, CTO, Idokorro Mobile. Ottawa, Ontario, CANADA. > http://www.markbaker.ca http://www.idokorro.com > >
Received on Thursday, 17 October 2002 16:30:29 UTC