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Re: change the question slightly maybe...schemas, leveraging their object orientedness??

From: Bill de hÓra <dehora@eircom.net>
Date: Tue, 21 Oct 2003 21:38:33 +0100
Message-ID: <3F959949.5060809@eircom.net>
To: noah_mendelsohn@us.ibm.com
Cc: Dean Hiller <dhiller@avaya.com>, Dare Obasanjo <dareo@microsoft.com>, xmlschema-dev@w3.org

noah_mendelsohn@us.ibm.com wrote:

> That said, I wouldn't leap too quickly to the assumption that "if only 
> schema had exploited the well known principles of object orientation, we'd 
> all be fine by now."  First of all, months of study were given to the use 
> of object orientation in schemas, and when you look carefully, there 
> really are a number of reasons that people use object orientation, and 
> interop across versions is just one.   For example, object orientation is 
> commonly used to allow for reuse and evolution at the source level.  I 
> believe that XML schema succeeds at this to a degree, both in the type 
> system and with substitution groups.

[XML being the logical conclusion of the visitor pattern]

In my experience the OO world is poor at versioning and would be the 
last place I'd look ore recommend looking for inspiration re schema 
design. The versioning problem seems to be an industry scale 
trainwreck. In middleware the answer to a versioning problem is an 
upgrade.

> So, I agree versioning is important.  I'm less convinced that the answer 
> for XML is primarily to be found in the world of object orientation.  XML 
> is data without behavior, somewhat the opposite of OO.

Strong agreement, but I doubt it has much to do with whether you 
couple data to processes or not - the versioning problem if anything 
is a special case of the naming problem and rides above how you 
organize code and data.

Bill de hÓra
Received on Tuesday, 21 October 2003 16:54:18 GMT

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