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'Re: "Re: Comparison of values of anySimpleType"'

From: Kasimier Buchcik <kbuchcik@4commerce.de>
Date: Mon, 01 Nov 2004 15:28:59 +0100
To: <noah_mendelsohn@us.ibm.com>
CC: <xmlschema-dev@w3.org>
Message-ID: <4186482B.20101@4commerce.de>

Hi,

Ahh, thanks for the hint; I did poke in XML Schema Part 2, and was too 
blind to see this obvious statement in XML Schema Part 1.

Hmm, observing the changed behaviour in Xerces-J 2.6.2 - it seems to 
dislike comparison with 'anySimpleType' now: does the XS world tend to 
move to disallow comparison with 'anySimpleType' here?

If using IDCs: is the simple/complex ur-type assumed for nodes, for 
which no declarations exist, if processed by skip/lax wildcards? Or are 
IDC fields restricted to resolve to declared (or xsi:type) nodes only?


Thanks & regards,

Kasimier


noah_mendelsohn@us.ibm.com wrote:
> From our brand, spanking new XML Schema 1.0 Second Edition Recommendation 
> [1]:
> "The mapping from lexical space to value space is unspecified for items 
> whose type definition is the ·simple ur-type definition·. Accordingly this 
> specification does not constrain processors' behaviour in areas where this 
> mapping is implicated, for example checking such items against 
> enumerations, constructing default attributes or elements whose declared 
> type definition is the ·simple ur-type definition·, checking identity 
> constraints involving such items.
> 
> Note: The Working Group expects to return to this area in a future version 
> of this specification."
> Key/keyref are what the Recommendation calls Identity Constraints.  So, 
> this is a rare case where processors implementing different validation 
> rules are all conforming.
> 
> Noah
> [1] 
> http://www.w3.org/TR/2004/PER-xmlschema-1-20040318/#Type_Definition_Summary
> 
> --------------------------------------
> Noah Mendelsohn 
> IBM Corporation
> One Rogers Street
> Cambridge, MA 02142
> 1-617-693-4036
> --------------------------------------
> 
> 
> 
> 
> 
> 
> 
> 
> Kasimier Buchcik <kbuchcik@4commerce.de>
> Sent by: xmlschema-dev-request@w3.org
> 10/20/04 07:45 AM
> 
>  
>         To:     <xmlschema-dev@w3.org>
>         cc:     (bcc: Noah Mendelsohn/Cambridge/IBM)
>         Subject:        Comparison of values of anySimpleType
> 
> 
> 
> Hi,
> 
> I have trouble understanding how 'anySimpleType' is handled if comparing 
> values. Xerces and XSV seem to differ here.
> 
> Identity-constraint example:
> (using Xerces-J 2.5.1, XSV 2.5-2, MSXML 4.0)
> 
> <sequence>
>    <element name="b" type="anySimpleType"/>
>    <element name="c" type="float"/>
> </sequence>
> 
> <b>1.0</b>
> <c>1.0</c>
> 
> with the value of 'c' being a keyref to the key value of 'b'.
> 
> Results: XSV and MSXML do not find the referenced key, Xerces does.
> 
> if both types are 'float':
> 
> Results: All tree validators find the referenced key.
> 
> I cannot find a hint for 'anySimpleType' being not comparable with the
> primitive types. The PER for datatypes says:
> 
> "anySimpleType is considered to have an unconstrained lexical space and 
> a ·value space· consisting of the union of the ·value space·s of all the 
> ·primitive· datatypes and the set of all lists of all members of the 
> ·value space·s of all the ·primitive· datatypes."
> 
> Further "4.2.1 equal" says:
> 
> "if a datatype T' is ·derived· by ·restriction· from an atomic datatype 
> T then the ·value space· of T' is a subset of the ·value space· of T. 
> Values in the ·value space·s of T and T' can be compared according to 
> the above rules "
> 
> Can someone explain?
> 
> Greetings,
> 
> Kasimier
> 
Received on Monday, 1 November 2004 14:29:50 UTC

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