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Re: Instantiating a DAML-S Process

From: Srini Narayanan <snarayan@ICSI.Berkeley.EDU>
Date: Thu, 14 Jun 2001 00:15:31 -0400 (EDT)
To: www-ws@w3c.org
Cc: Srini Narayanan <snarayan@ICSI.Berkeley.EDU>
Message-ID: <20010613211502.A12780@tamari.ICSI.Berkeley.EDU>
Hi David, 

A bit more of follow-up to David Martin's reply, esp. wrt your second
question.

> So in the example above,
> every type in the sequence is either a SignIn type or a LoadProfile
> type.  However, the sequence says nothing about the order of the types,
> or how many types should be in it.  So, this seems to be only part of
> the specification, or maybe not even the right way to specify such a
> condition.  Is this true?

Yes, good point! I think this relies on a daml+oil
hack which is in http://www.daml.org/2001/03/reference.html#collection.

        Whenever an element has the rdf:parseType attribute with value
       "daml:collection", the enclosed elements must be interpreted as elements
        in a list structure, constructed using the elements List, first, rest
        and nil .

So the list structure will preserve the ordering. And one could add
cardinality information to the components list to specify the length
of the sequence. Note, this does not say anything more about the
execution semantics.  

A way to make this clear is to use the ProcessList attribute for
sequences.  This is defined in Process.daml. We are planning to use
this for describing sequences of processes instead. Thus the
"components" property of the sequence process should be of type ProcessList
(list of processes). Then the first "item" property of the list would
be restricted to be of type SignIn and and the second to be of type
LoadProfile. 

Regards,

Srini Narayanan
 
Received on Thursday, 14 June 2001 03:09:54 GMT

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