[XPath 2.0] XSCH-XPATH-003

Dear Colleagues,

This comment pertains to the Nov. 12 2003 version of XPath 2.0 [1].

[1] http://www.w3.org/TR/xpath20/

Lisa Martin, on behalf of the XML Schema Working Group
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Section 2.4.4 Sequence Type Matching

   In the definition of type-matches in 2.4.4, known and unknown derived
   types are treated differently with respect to derivation by extension
   and restriction. Implementations are free to return true if they can
   determine that unknown types are derived by restriction but not if they
   are derived by extension or a mix of extension and restriction steps,
   whereas known types will return true if derived by any means.   If this
   non-parallelism is intentional, an explanatory note might help avoid
   confusion on the part of readers.   If it is not intentional, it should
   be fixed.   In addition, the rules are careful to say "derived by one or
   more steps of restriction or extension" but say simply "derived by
   restriction".   Is it intended that this be confined to a single
   derivation step?   Or would one or more restriction steps be OK?

Received on Sunday, 15 February 2004 13:28:22 UTC