Re: OCL 2.0 finalizatioon



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From: Jos Warmer (J.Warmer@klasse.nl)
Date: Mon 03 Nov 2003 - 15:21:36 GMT


Herman,

we removed all operations from the OCL library that provided access to the 
metalevel.
This was done because UML 2.0 would include access to the meta-level and we 
did not want
to have this functionality defined twice (in the UML core and in the OCL) 
within the UML 2.
Also, thye approach to access the metalevel through "allAttrubutes" and its 
companions was
half-baked, because it only allowed attribute names, nit their types oir 
any other useful
metainformation.

I agree that this functionality should be avialable, someone should check 
whether this can be done
through the core UML or not.

Josh


At 16:14 3-11-2003 +0100, Steffen Zschaler wrote:
>Dear Herman,
>
>I am not quite sure we really ever added this additional operation (this 
>is because I can't presently find it in the copies of the drafts I have 
>lying around). Anyway, if we did, this was only because we needed this 
>additional operation to formulate WFRs. Now we don't need this additional 
>operation, so it is no longer in the spec.
>
>It is not the job of the OCL specification to define additional operations 
>on the UML metamodel beyond what is needed by the OCL specification 
>itself. Therefore, I would propose to leave things as they are and not to 
>(re-)introduce allAttributes.
>
>Kind regards,
>
>Steffen Zschaler
>
>Herman Balsters schrieb:
>>
>>Dear Jrn,
>>
>>Thank you for your quick reply.
>>
>>Let me think about your idea to coordinate (part of) the effort regarding
>>this issue on basic revisions of OCL 2.0 at a later stage next year.
>>Perhaps I might be interested.
>>
>>I do have a minor point. In pre-OCL 2.0 versions, there was an
>>operator called  "allAttributes": this operator (to be applied to class
>>objects) returns the set of attributes of that object. (This operator
>>should also be applicable to tuples as well, by the way.) Now the
>>strange thing has happened that this most useful operator has
>>vanished in OCL 2.0  I propose that it be re-introduced.
>>
>>That's it.
>>
>>Kind regards,
>>
>>Herman
>>
>>
>>
>>
>>
>>On 3 Nov 2003 at 15:41, Jrn Guy S wrote:
>>
>>
>>>
>>>Dear Herman,
>>>
>>>The task of the current FTF is only to correct minor flaws in the 
>>>specification as is. Basic revision and changes will be undertaken in a 
>>>further round expected in the middle of next year. Nobody has yet 
>>>volunteered to collect items for that stage of revision, but he or she 
>>>would probably be
>>>
>>
>>greatly welcomed. In my opinion this would help to infuse the OMG process 
>>with some of the basic research done in this field. I already have issues 
>>to this end and will add yours to be handed to however picks up at that 
>>point. How do you feel about coordinating this effort?
>>
>>>
>>>To keep up: We use the Precise UML Mailing list for discussion, you can 
>>>see the previous activity at
>>>
>>><http://www.cs.york.ac.uk/puml/puml-list-archive/>http://www.cs.york.ac.uk/puml/puml-list-archive/
>>>
>>>
>>>Kind regards,
>>>
>>>Jrn Guy S
>>>
>>>Dipl.-Inform. Jrn Guy S            | CIS - Sekr. EN7
>>>phone / fax : +49(30) 314-23553/21601 | TU Berlin, Fak IV
>>>phone (secretary) : +49(30) 314-23555 | Einsteinufer 17
>>><mailto:jgsuess@cs.tu-berlin.de>mailto:jgsuess@cs.tu-berlin.de        | 
>>>D-10587 BERLIN / GERMANY
>>>
>>>
>>>
>>>-----Original Message-----
>>>From:   Herman Balsters 
>>>[<mailto:h.balsters@bdk.rug.nl>mailto:h.balsters@bdk.rug.nl]
>>>Sent:   Monday, November 03, 2003 3:18 PM
>>>To:     <mailto:jgsuess@cs.tu-berlin.de>jgsuess@cs.tu-berlin.de
>>>Subject:        OCL 2.0 finalizatioon
>>>
>>>Dear Jorg,
>>>
>>>I heard from Sten Loecher that you are the contact person for
>>>proposals for finalizing OCL 2.0
>>>
>>>I did not attend the OCL workshop, but I did give a presentation at the
>>>UML conference.
>>>
>>>I have a proposal for ammending OCL 2.0.
>>>
>>>In my paper  "Modeling Database Views with Derived Classes in the
>>>UML/OCL-framework" of this years UML conference (see proc. pp.
>>>295-309) I investigated the issue of expressibility of OCL 2.0 w.r.t. to
>>>the query langauge SQL.  I have demonstrated in that paper that OCL
>>>2.0 is not as expressive as SQL (as opposed to common belief), and
>>>that OCL needs an additional "tuplejoin" operator to achieve the
>>>desired result.
>>>
>>>To whom do I have to address this issue? If you need more details on
>>>the actual ammendment, I can provide them (they are also in my
>>>paper).
>>>
>>>Beste regards,
>>>
>>>Herman Balsters
>>>
>>>dr. H. Balsters
>>>Faculty of Business Science
>>>University of Groningen
>>>The Netherlands
>>>
>>>
>>>
>>
>>
>>dr. H. Balsters
>>Faculty of Business Science
>>University of Groningen
>>The Netherlands
>>
>>
>>
>>
>>To remove yourself from this list please mail 
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>>
>>
>
>
>--
>Dipl.-Inf. Steffen Zschaler
>Research Assistant
>
>Dresden University of Technology
>Department of Computer Science
>
>Phone +49 351 463 38555
>Fax   +49 351 463 38459
>Email 
><mailto:Steffen.Zschaler@inf.tu-dresden.de>Steffen.Zschaler@inf.tu-dresden.de


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