RE: ORA-FO-266-B: Error codes should be normative (2)

I think there is another reason for not making error codes normative at
this stage: the currently assigned codes are simply not good enough. I
found, for example, cases where the XPath language book and F+O define
different codes for the same casting error. Some codes are incredibly
broad in scope, other very narrow, and the scopes overlap. A lot of
design work is needed on the overall set of error codes before we can
make them normative.

Michael Kay

> -----Original Message-----
> From: public-qt-comments-request@w3.org 
> [mailto:public-qt-comments-request@w3.org] On Behalf Of Michael Rys
> Sent: 18 February 2004 00:53
> To: Stephen Buxton; public-qt-comments@w3.org
> Subject: RE: ORA-FO-266-B: Error codes should be normative (2)
> 
> 
> 
> Since the W3C produces recommendations that need to be 
> validated by interoperable implementations, I doubt that you 
> can find two interoperable APIs for different implementation 
> environment where you can test such assertions.
> 
> I think that the error codes should be recommendations (in the English
> meaning) but that different APIs and embeddings of XQuery 
> specify how such error codes are being mapped into the 
> appropriate environment.
> 
> Best regards
> Michael
> 
> > -----Original Message-----
> > From: public-qt-comments-request@w3.org [mailto:public-qt-comments- 
> > request@w3.org] On Behalf Of Stephen Buxton
> > Sent: Tuesday, February 17, 2004 2:44 AM
> > To: public-qt-comments@w3.org
> > Subject: ORA-FO-266-B: Error codes should be normative (2)
> > 
> > 
> > SECTION Annex D: Error Summary
> > 
> > The F&O document (as well as other documents) summarize 
> error codes in
> an
> > Annex that is labelled to be non-normative.  In some ways, 
> this makes 
> > sense, because XQuery does not specify any sort of an API by which
> errors
> > can be "returned" to any entity.  However, it is clear that 
> there will
> be
> > more than one such API (e.g., JSR 225, XQJ, is defining such an API
> for
> > use by Java programmers).
> > 
> > It would be a serious problem if each API, and each XQuery
> implementation,
> > were free to return radically different error codes for identical
> errors,
> > as programmers would be unable to write code that is portable among
> XQuery
> > engines.
> > 
> > Some way to make the error codes themselves normative (but, 
> of course,
> > *not* the natural-language phrase that is associated with 
> the codes).
> > 
> > One approach might be to state that whenever the XQuery 
> specification 
> > indicates that a specific error is to be raised, that the specified
> > (normative) error code must be made available in an
> implementation-defined
> > way to the agent that caused the XQuery to be evaluted by 
> the XQuery 
> > engine.  This is crude and clumsy, but definitely better 
> than nothing! 
> > The alternative would be to create an SQL-like diagnostics facility
> that
> > would allow users to execute a subsequent query to retrieve 
> the error 
> > code, etc.  I doubt that would be acceptable for XQuery 
> 1.0, but would
> be
> > deferred to a future version.
> > 
> > - Steve B.
>

Received on Wednesday, 18 February 2004 03:15:25 UTC