W3C home > Mailing lists > Public > www-ws@w3.org > September 2003

Re: Multiple inputs and multiple outputs

From: Drew McDermott <drew.mcdermott@yale.edu>
Date: Sun, 28 Sep 2003 14:48:52 -0400 (EDT)
Message-Id: <200309281848.h8SImqu15609@pantheon-po04.its.yale.edu>
To: www-ws@w3.org


   [Yuzhong Qu" <yzqu@seu.edu.cn>]
   As we know, a process in DAML-S can have multiple inputs and multiple (conditional)outputs.
   (From http://www.daml.org/services/owl-s/1.0/Process.owl
   http://www.daml.org/services/owl-s/0.9/Process.owl)

   1. In the case of  multiple inputs

       It seems to me that the process specified should take multiple
       inputs satisfying corresponding type constraint.
       Am I right?

Yes.

       But, how do you know the exact number of inputs? You just know
       what you know, maybe there is another statement about a new
       input (another input may be specified in other place) due to
       the openness of the Semantic Web (it's not a closed world).

Good point.  We really need a fixed list of inputs and another of outputs.
[It would be interesting denial-of-service attack to tell a service
that it needed another input and have it then stall because no one is
supplying it. :)]

   2.  In the case of  multiple outputs

       What's the intended meaning?

Putting aside the issue of conditional outputs for a moment, if the
process has outputs A,B,C, it just means (in essence) that the output
is a record whose fields are called A, B, and C.

A conditional output might not even exist, so you can picture it has
always being there, but having a Null value when the condition isn't
true.

-- 
                                             -- Drew McDermott
                                                Yale Computer Science Department
Received on Sunday, 28 September 2003 14:48:53 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Tuesday, 3 July 2007 12:25:44 GMT