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[Bug 2045] R-181 (Datatypes): clarify equality and identity of lists (error, corrigendum needed)

From: <bugzilla@wiggum.w3.org>
Date: Thu, 08 Sep 2005 22:20:12 +0000
To: www-xml-schema-comments@w3.org
Cc:
Message-Id: <E1EDUke-0004wd-6b@wiggum.w3.org>

http://www.w3.org/Bugs/Public/show_bug.cgi?id=2045

           Summary: R-181 (Datatypes):  clarify equality and identity of
                    lists (error, corrigendum needed)
           Product: XML Schema
           Version: 1.0
          Platform: PC
               URL: http://www.w3.org/2001/05/xmlschema-rec-
                    comments.html#pfiListEquality
        OS/Version: Linux
            Status: NEW
          Severity: normal
          Priority: P2
         Component: XSD Part 2: Datatypes
        AssignedTo: cmsmcq@w3.org
        ReportedBy: cmsmcq@w3.org
         QAContact: www-xml-schema-comments@w3.org


[This issue was originally raised by Stefan Wachter in
November 2002.  It was booked as Rec Comment R-181 and is
now being transferred into Bugzilla.]
 
When a list valued element or attribute is used as a key
then the equality of the values is important. In the
following example there are 3 lists with item types "Name",
"double", "nameOrDouble":

  <simpleType name="l1">
    <list itemType="Name"/>
  <simpleType>
  
  <simpleType name="l2">
    <list itemType="double"/>
  <simpleType>
  
  <simpleType name="l3">
    <list itemType="tns:nameOrDouble"/>
  <simpleType>
  
  <simpleType name="nameOrDouble">
    <union memberTypes="Name double"/>
  <simpleType>
  
Are these lists equal?
  
     1. Items types of lists are different but item types of
        items are equal: 

          <element xsi:type="l1">1.0 2.0<element> 
          = <element xsi:type="l3">1.0 2.0<element>

     2. Item types of lists are different but there are no
        items.

          <element xsi:type="l1"/> 
          = <element xsi:type="l2"/>

What are the exact rules for comparing lists?

Originally raised in:
http://lists.w3.org/Archives/Public/xmlschema-dev/2002Nov/0066.html

Response from Henry Thompson on 18 November 2002, agreeing
that the rules should be cleaned up.
http://lists.w3.org/Archives/Public/www-xml-schema-comments/2002OctDec/0051.html

Proposal from Ashok Malhotra, 29 November 2003:
http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2003Nov/0054.html

Discussed at the 2004-02-12 telecon. Decided that we need
new draft text based on current 2E.

Discussed again at the May 2005 face to face meeting.

Action NC2005-15: Datatype editors to resolve R-181 by
defining identity and equality of lists in terms of pairwise
member identity and equality, respectively.

Note that we need both a 1.0 corrigendum and a wording
proposal for 1.1.  Because identity and equality are
distinct relations in 1.1 but not in 1.0, the wording
proposals will not necessarily be the same.  This
record is for the 1.0 corrigendum.
Received on Thursday, 8 September 2005 22:20:14 GMT

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