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"fixed" property of "length" facet.

From: Kohsuke KAWAGUCHI <kohsuke.kawaguchi@eng.sun.com>
Date: Thu, 29 Mar 2001 10:45:20 -0800
To: www-xml-schema-comments@w3.org
Message-Id: <20010329103359.6735.KOHSUKE.KAWAGUCHI@eng.sun.com>

Dear XML Schema WG members,


The spec indicates that "length" facet has "fixed" property (in section
4.3.1).

But it's useless.


When deriving a type X that has "length" facet by restriction, the
derived type Y can never have "length" facet with different value,
because no lexical value can match two different lengths.

The same thing happens when deriving a type by list.

So regardless of the presence of fixed="true", derived types cannot
specify a value for "length" facet.


Also, "schema constraint: length valid restriction" doesn't make sense, either.
It says,

> It is an error if length is among the members of {facets} of {base type
> definition} and {value} is greater than the {value} of the parent
> length. 

As I pointed out, only one "length" facet can be specified for one
derivation chain. So there never be a chance for two "length" facet with
different value to co-exist. It doesn't matter whether it is greater or
less.

So this should be modified to

> It is an error if length is among the members of {facets} of {base
> type definition} and {value} is not equal to the {value} of the parent
> length.



regards,
----------------------
K.Kawaguchi
E-Mail: k-kawa@bigfoot.com
Received on Thursday, 29 March 2001 13:45:54 GMT

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