- From: Drew McDermott <drew.mcdermott@yale.edu>
- Date: Mon, 19 Sep 2005 13:27:12 -0400
- To: public-sws-ig@w3.org
- CC: drew.mcdermott@yale.edu
> [Ale <ale_univ@yahoo.it>]
> this is just a simple question... what is the right way to binding
> parameter when using ControlStruct different by Sequence??
> What if I decide to use choice? how can I specify which inputs and
> outputs of which service in the bag have to be binded with input and
> ouput of the overall service if I don't know which service will be
> executed? Have to specify that ALL inputs and ALL outputs from within
> the bag could be binded ith the external Composite process?
Unfortunately, the answer is Yes. For instance, if step B gets its
inputs either from step A1 or step A2 from a Choice, then it must
indicate both possibilities:
(A1 :: alternative1
;? A2 :: alternative2);
perform action(x <= A1.u, y <= A1.v,
x <= A2.u, y <= A2.w)
Whenever a perform argument gets the same input from more than one possible
source, it must be the case that the two sources are mutually
inconsistent (either because they come from different branches of a
'choice', or from different branches of an 'if').
If this is too clumsy, one way to fix it would be to generalize
'produce' so it applies to intermediate control constructs, not just
to the output of entire processes. We will probably supply such a
syntax on the next revision, when we provide a notation for dataflow
through loops.
--
-- Drew McDermott
Professor,
Computer Science Department
Yale University
Received on Monday, 19 September 2005 17:30:38 UTC