[wsbpel-spec-edit] Issue 94

Hi all,

I would like to send this proposal for Issue 94 to this editing
subgroup first, before sending it to the main BPEL TC mailing list.

Some background from Issue 95: 

(You can skip this part, if you don't care too much about the usage of
schema validation)

A <rethrow /> activity element is introduced for Issue 95
(Rethrow a fault). In theory, we can use schema validation to make sure
rethrow happens only within a fault handler. However, since XMLSchema
version 1.* is mainly context free grammar like (as opposed to context
sensitive), we may need to duplicate a lot of XML definition (e.g.
"activity" vs "activityOrRethrow"; "tSequence" and
"tSequenceWithRethrow" and etc), in order to achieve this constraint in
schema validation. This kind of  overhead may be too much for such a
minor syntax differentiation. Therefore, an easier route is taken by
just adding "rethrow" to group "activity" and using implied semantics
of the text of the main spec doc to carry out the post-schema
validation 

Therefore, I suggest to take a similar route for Issue 94

Future version of XML Schema (2.0?) may allow us to add "co-constraint"
to specify this kind of contraints more effectively. 

Proposal to fix issue 94:

(1) Adding compensate to group "activity"

(2) merge tActivityContainer and tActivityOrCompensateContainer

      by replacing all tActivityOrCompensateContainer with
tActivityContainer

        [That means: all tActivityContainer now allows compensate
activity. 

           We should specify in the text in our spec that compensate
activity is allowed only 

            within a compensation handler]

What do you guys think?

If you guys feel OK about this proposal, I will forward this proposal
to the main BPEL TC mailing list.

Thanks!

Regards,

Alex Yiu