[Bug 1637] [FS] collations can have a third, optional, mapping

http://www.w3.org/Bugs/Public/show_bug.cgi?id=1637


jim.melton@acm.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED




------- Additional Comments From jim.melton@acm.org  2005-07-22 17:38 -------
This is the official response of the XML Query WG and the XSL WG. 

The definition of a collation in F&O (All collations support the capability of
deciding whether two strings are considered equal, and if not, which of the
strings should be regarded as preceding the other.) differs, as you have
observed, from the definitions in Formal Semantics (a collation consists of two
functions: "the first function takes a set of strings and returns a sequence
containing those strings in sorted order; and the second function takes two
strings, returns true if they are considered equal, and false if not.") and XQuery.

Even though the definitions do not correspond directly, we do not believe this
to be a problem.  The definition in the Formal Semantics serves the requirements
of Formal Semantics (and the analogous definition in XQuery/XPath serves those
documents' requirements), while the definition in F&O serves that document's
purpose.  It is apparent to us that the two functions identified in the Formal
Semantics definition can be used to derive the information that F&O says all
collations support.

The fact that F&O adds a further requirement (For other functions, such as
fn:contains(), the collation needs to support an additional property: it must be
able to decompose the string into a sequence of collation units...) does not, in
our minds, imply that there needs to be an additional function to cause such
decomposition to take place.  Instead, we believe that the two functions
identified by Formal Semantics are required to have that decomposition
capability in order to perform their jobs.  That is, although some collations
(e.g., fn:compare()) can be performed without worrying too much about collation
units, other collations (e.g., fn:contains()) cannot.  But the former collection
of functions do not suffer in any way if the collation happens to do such a
decomposition.

Our conclusion is that no changes to the documents are required because the
definitions are consistent and adequate as written.  We regret that our response
to the previous comment
(http://lists.w3.org/Archives/Public/public-qt-comments/2004Feb/0910) did not
directly address this particular concern.  We hope that this response satisfies
your concerns in this regard. 

The WGs also note that the dynamic evaluation sections of Formal Semantics is
non-normative. 

We appreciate your feedback on the XML Query specifications.  Please let us know
if this response is satisfactory.  If it is, please mark the bug as CLOSED.  If
it is not, please respond to this message, explaining your concerns.

Received on Friday, 22 July 2005 17:38:26 UTC