Category Archives: version

Balisage

Balisage 2008 (formerly Extreme Markup) in Montreal is drawing to a close. I’ve had a great time here, and my presentation ‘Axioms of Versioning‘ went very well. There was an entire day dedicated to Versioning, with all great contributions, especially … Continue reading

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Axioms of Versioning 2

I’ve written a new version of ‘Axioms of Versioning‘. I extended the formalization to get a grasp of the concept of ‘Semantic Backward Compatibility in HL7v3, which I believe is flawed (quote: “Objective of backward model compatibility is that a … Continue reading

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Making All Changes Compatible over Multiple Versions – Part 2

In the previous article I showed how to add an optional element and make this a compatible change over two releases, so existing receivers aren’t broken by unknown elements. It is done by following two simple principles: have one or … Continue reading

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Making All Changes Compatible over Multiple Versions – Part 1

This article will show a way to make any change in an XML-based exchange vocabulary compatible over several versions of the exchange language. In environments where there is some control over the number of versions ‘in the field’ this is … Continue reading

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Axioms of Versioning

Obsolete, please see the latest version Version 1 An attempt to define syntactical and semantical compatiblity of versions in a formal way. Much derives from the writings of David Orchard, especially the parts on syntactical forward and backward compatibility (though … Continue reading

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More Compatibility Flavours

See also my previous posts on this issue. So we’ve got backward and forward compatibility, and syntactical and semantical compatibility. (Quick recapture: Backward compatibility is the ability to accept data from older applications, forward compatibility the ability to accept data … Continue reading

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Syntactical and Semantical Compatibility

In a previous post I summarized some concepts from David Orchard’s W3C TAG Finding ‘Extending and Versioning Languages‘. Now I’ll make things complicated and talk about syntactical and semantical compatibility. When I send you a message we can distinguish syntactical … Continue reading

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On Compatibility – Back and Forth

Compatibility in data exchanges is very different from – and much more complex than – compatibility in traditional software. David Orchard has written extensively about it in a W3C TAG Finding, ‘Extending and Versioning Languages‘. I’ve given some thought to … Continue reading

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