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Implemenation flexibility for representations of unbounded properties

From: Peter Canning <canning@vitria.com>
Date: Tue, 09 May 2000 12:27:58 -0700
Message-Id: <>
To: xmlschema-dev@w3.org
When the Structures specification says that the type of a property of a 
schema component is a type whose values have unbounded size, what 
flexibility does an conforming implementation have for representing that 
property using finite sized language types?

For example, the "min occurs" property of the "Particle" component is 
specified (in section 3.8) as being a non-negative integer.  The 
description of non-negative integer (in section 3.3.15 of the Datatypes 
specification) says that the value space is the infinite set {0, 1, 2, 
...}.  This implies to me that values could be arbitrarily large (the table 
in Appendix C claims that the bounded property of non-negative integer is 
true, but I believe that is an error).  Are implementations required to 
support arbitrarily large values for the "min occurs" property?  If not 
what are they required to support?

The similar situation obviously occurs for string valued properties, and 
probably for others

It would be helpful if the specification gave some guidance in the 
requirements for conformance is these kinds of areas.  If implementations 
have flexibility to use finite representations, it may make sense that they 
be encouraged to document their constraints (similar to how many C compiler 
document how they implement the implementation dependant areas of ANSI C).

	Peter Canning
Received on Tuesday, 9 May 2000 15:28:02 UTC

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