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Re: Question on XML Schema 1.1 [vc:maxVersion]

• From: Michael Kay <mike@saxonica.com>
• To: xml-dev@lists.xml.org
• Date: Fri, 21 Jan 2011 12:23:10 +0000

On 10/01/2011 22:29, Ramkumar Menon wrote:

Sorry for the delay in responding to this. If you are interested in such 
questions, asking on the W3C schema-dev list would be a better way of 
getting information and feedback.
> Gurus,
> Two questions on the version control namespace in XML Schema 1.1.
>  a) Why did we chose to have maxVersion be exclusive of the value?
>      i.e.
> <element name="Price" vc:minVersion="1.1" vc:maxVersion="2.4"/>
>    Its tricky for a person to read this as
>    "Price" element will be removed on pre-processing if we are using 
> XSD version 2.4.

The rule was adopted so that you can say that you want your schema to 
work with all the 1.x releases but not with 2.0, without knowing how 
many 1.x releases there will be. (In practice, I'd be inclined to write 
vc:maxVersion="1.99999" as it seems clearer to the reader.)
> b) Are we assuming that version numbers for XML Schema MUST be 
> decimals, now and later? Exposing terms such as minVersion and 
> maxVersion indicate so.
>
Yes. We thought it unlikely that W3C would depart from the practice of 
using decimal numbers as version numbers for the specification. If there 
were a primitive type for "Dewey-decimal" type numbering (1.5.7.2) then 
we might well have chosen it; but there isn't, and defining such a type 
for this specific purpose would be overkill.

Michael Kay
Saxonica

• References:
  • Question on XML Schema 1.1 [vc:maxVersion]
    • From: Ramkumar Menon <ramkumar.menon@gmail.com>