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Bug 2857 - RQ-7 Improve interaction between wildcards and substitution groups (wildcards)
Summary: RQ-7 Improve interaction between wildcards and substitution groups (wildcards)
Alias: None
Product: XML Schema
Classification: Unclassified
Component: Structures: XSD Part 1 (show other bugs)
Version: 1.1 only
Hardware: Other All
: P4 normal
Target Milestone: ---
Assignee: C. M. Sperberg-McQueen
QA Contact: XML Schema comments list
Whiteboard: important, hard, restriction cluster
Keywords: resolved
Depends on:
Reported: 2006-02-11 01:42 UTC by C. M. Sperberg-McQueen
Modified: 2006-10-21 20:48 UTC (History)
0 users

See Also:


Description C. M. Sperberg-McQueen 2006-02-11 01:42:51 UTC
This issue was originally reported by Matthew Fuchs.

Address problems with the interaction between wildcards and
substitution groups. 

Specifically, resolve the bug where if complex type A has a wildcard,
and B restricts A, then it can restrict the wildcard to a set of
elements that match the wildcard. Not all elements in the substitution
groups of those elements necessarily match the wildcard - so B is not
a subset of A.

See (member-only link), ( 

Cf. RQ-135 (#component-consistency-and-validity).

This item was discussed, and phase-1 agreement was reached, in the
meeting of 2004-03-18

    All we need to say to discharge this requirement is that
    restriction is transitive.  The types derived by multiple
    restriction steps should also obey the wildcard.  There was some
    doubt over whether the constructive rules of XML Schema 1.0
    achieve this, but the definition of restriction in section 2 seems
    to entail it.

According to the requirements document, phase-1 agreement has been reached.
Comment 1 C. M. Sperberg-McQueen 2006-10-21 20:33:13 UTC
On 20 October 2006, the WG agreed to close this issue as having
been resolved, with the rationale:

      This is dealt with by the elimination of the constructive
      rules for restriction and the definition of the rule that
      elements locally valid against the restriction must be
      locally valid against the base.  The consequence is that
      replacing a wildcard by a reference to an element does not
      necessarily constitute a valid restriction.