W3C home > Mailing lists > Public > public-ws-chor@w3.org > April 2003

Re: Feedback on Glossary

From: Assaf Arkin <arkin@intalio.com>
Date: Tue, 22 Apr 2003 20:27:34 -0700
Message-ID: <3EA60826.50408@intalio.com>
To: "Cummins, Fred A" <fred.cummins@eds.com>
CC: "Monica J. Martin" <monica.martin@sun.com>, public-ws-chor@w3.org

>>I picked this interesting definition from, or all places, pi-calculus:
>>A process is generally nothing more than a set of commitments.
>[fac] This seems a bit too simplistic.  One could infer that a process
>does'nt actually accomplish anything
It's not a full definition, only some sentence that popped out of 
nowhere. This mention is buried casually in some other topic of 
discussion, but when I bumped into it accidentally I found it very 
interesting to mention.

We have requirements from the B2B space that talk about legal 
commitements and fulfilling these commitements, and I just found it very 
interesting that a very low-level model such as pi-calculus actually 
acknowledges the same fact.

>Some state transitions are better defined as graphs depicting the 
>possible transitions between a finite set of states. For example from 
>submitted to approved to pending to shipped. Other state 
>transitions are 
>not easily modeled as graphs like that. For example, if I 
>have a price 
>for the order and I need to add shipping & handling based on the 
>destination and weight, the transition is from some number N to some 
>other number N. Do I write a graph with all possible state 
>transition s 
>or are there some transitions not modeled as a graph? Can we identify 
>more generically these two types of states and transitions?
>[fac] I wonder if we couldn't leave this discussion to the definition
>of state transition.
Yes. We may at the end decide to talk only about these specific states 
that you can model as a graph of state transitions,

>>WSDL interface defines some of the expected behavior of a 
>>service type 
>>and WS-Chor defines other part of that behavior. WSDL can 
>>also define an 
>>interface beloning to that type by associating it with the interface. 
>>However, somewhere along the actual concept of service type 
>>managed to 
>>escape and I think we need to introduce it in more generic terms than 
>>the particular type of WSDL definition used to capture its behavior.
>[fac] Is your intent to attach some additional semantics to a service
>type?  If not, what will distinguish one service type from another if not
>the WSDL and choreography?
If you think about it, WSDL is just a type definition language for 
services. It defines generic types (interfaces) and actual instances of 
these types (services). I can say that some choreography can use any 
service that implements interface X, or simply that it can use any 
service of that type. So service type is just a more generic term and a 
WSDL interface is just part of the definition of that type.

The only need to generalize this concept a bit is by allow different 
defintions of the service type to exist without naming this particular 

Received on Tuesday, 22 April 2003 23:29:11 UTC

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