[Bug 3852] K-NumericAdd-5 and K-NumericAdd-6 are bad tests

http://www.w3.org/Bugs/Public/show_bug.cgi?id=3852

           Summary: K-NumericAdd-5 and K-NumericAdd-6 are bad tests
           Product: XML Query Test Suite
           Version: 1.0.1
          Platform: PC
        OS/Version: Linux
            Status: NEW
          Severity: normal
          Priority: P2
         Component: XML Query Test Suite
        AssignedTo: andrew.eisenberg@us.ibm.com
        ReportedBy: john.snelson@oracle.com
         QAContact: public-qt-comments@w3.org


I note that these tests have already been discussed in Bug #3346.

The tests follow this pattern (K-NumericAdd-6 uses float instead of double):

xs:double(1.1) + xs:double(2.2) ne 3.3

where the expected test result is "true".

I would suggest that this is a bad test since it assumes that the
implementation's numeric format is base-2 based. If the underlying numeric
format is base-10 based (as Berkeley DB XML's is), then the test will quite
rightly give a result of "false".

Similarly, I believe it would be perfectly acceptable (and indeed usual) to
provide a certain margin of tolerence when comparing base-2 based floating
point numbers - for this very reason. Another XQuery processor's implementation
could provide tolerence enough to also give a result of "false".

I suggest that the tests either be changed to use numbers that are a little
less controversial, or that they are removed altogether.

John

Received on Thursday, 19 October 2006 11:26:18 UTC