Issue 998 - State that sequential lexically ordering is the default for interpretation of CDL

Dear Colleagues,
 
I was hoping to illustrate the point of this issue by taking some of the
examples from the the specification directly, but unfortunately they are all
a bit too simple in that they only have one activity in a series.  The point
I am addressing comes into play when there is more than one activity in
series in the choreography description not wrapped in an explicit SEQUENCE,
PARALLEL or CHOICE construct, which is currently permitted.  So I have just
taken a couple of partially filled out examples to illustrate the point.
 
Are:

<workunit  name="StockCheck" 

           guard="cdl:getVariable('StockQuantity','','"/Product/Qty"', 

                                  '"tns:Retailer") > 10')"            

           block="false" >

   ... <!--some activity -->

   ... <!--some other activity -->

</workunit>

 
and 

<workunit  name="StockCheck" 

           guard="cdl:getVariable('StockQuantity','','"/Product/Qty"', 

                                  '"tns:Retailer") > 10')"            

           block="false" >

   ... <!--some other activity -->

   ... <!--some activity -->

</workunit>

the same?  (Where typically 'some activity' would be an interaction and
'some other activity' would be a different interaction.)

Another pseudo example:

<workunit  name="StockCheck">

   ... <interaction name="1" ...>

   ... <interaction name="2" ...>

</workunit>

workunit  name="StockReplenish">

   ... <interaction name="3" ...>

</workunit>

and

workunit  name="StockReplenish">

   ... <interaction name="3" ...>

</workunit>

<workunit  name="StockCheck">

   ... <interaction name="2" ...>

   ... <interaction name="1" ...>

</workunit>

 

I hope this makes the point clear  One solution is to include a default
ordering statement in the specification as the issue suggests.  Another
solution is to declare all of the above examples illegal CDL and state that
when more than one activity is placed lexically next to another (and they do
not have to be of the same type) then they MUST be wrapped with and explicit
SEQUENCE, PARALLEL or CHOICE activity.

 

 Best Regards,

Tony                           


 <http://www.choreology.com/> 

Tony Fletcher

Technical Advisor 
Choreology Ltd.
68, Lombard Street, London EC3V 9L J   UK


Phone:  

+44 (0) 1473 729537


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