RE: 7.10.4 (PR#147)

Hi Michael,

I agree that in the general case, without looking at the specific 
functions at hand, it might seem very short-sighted.

The real question that needs an answer is whether the difference of 
semantic breaks the real uses cases we have for this function, which are

1) Compare two dates 
seconds-from-dateTime(D1) < seconds-from-dateTime(D2)

2) Difference, which can be string manipulated into a duration if needed
seconds-from-dateTime(D1) - seconds-from-dateTime(D2)

3) Compute 2 hours from now
adjust-dateTime-to-timezone(seconds-to-dateTime(seconds-from-dateTime(now()) 
+ 7200))

Can you let us know please if you think the difference of semantic will 
break one of these three expressions?

Thank you,
John M. Boyer, Ph.D.
STSM: Lotus Forms Architect and Researcher
Chair, W3C Forms Working Group
Workplace, Portal and Collaboration Software
IBM Victoria Software Lab
E-Mail: boyerj@ca.ibm.com 

Blog: http://www.ibm.com/developerworks/blogs/page/JohnBoyer





"Michael Kay" <mike@saxonica.com> 
Sent by: www-forms-editor-request@w3.org
10/18/2007 01:53 AM

To
"'John Boyer'" <xforms-issues@mn.aptest.com>
cc
<w3c-xml-query-wg@w3.org>, <www-forms-editor@w3.org>
Subject
RE: 7.10.4 (PR#147)







 
Well, I'm clearly not going to persuade you, but it seems a very
short-sighted attitude to me.

If the XForms specification doesn't support XPath 2.0 until 2010, then an
increasing number of vendors will support it unilaterally (some already 
do),
which means the coexistence and transition issues will be even worse.

In any, case, the argument seems a bit like the millenium bug: we won't
worry about this problem because it will be three years before users 
notice
it.

Michael Kay


> -----Original Message-----
> From: John Boyer [mailto:xforms-issues@mn.aptest.com] 
> Sent: 18 October 2007 09:27
> To: mike@saxonica.com
> Cc: w3c-xml-query-wg@w3.org; www-forms-editor@w3.org
> Subject: Re: 7.10.4 (PR#147)
> 
> Hi Michael,
> 
> I received your follow-up recommending that we add 
> seconds-from-1970() and deprecate seconds-from-dataTime() to 
> make future updating to XForms 2.0/XPath 2.0 easier.
> 
> This only seems to add confusing complexities to XForms 1.1 
> in order to make at best a minor improvement to the future 
> update capabilities.  The update of 1.x content to XForms 2.0 
> should have much bigger issues than this.
> It is also by no means clear that a form author undergoing 
> such a large update of content would even want to retain the 
> 1970 semantic anyway because the typical call of these 
> functions is to do date math and comparisons.
> 
> Finally, it should be noted that the current estimated 
> (optimistic) timeframe for an XForms 2.0 recommendation is 
> the end of 2010.
> 
> Best regards,
> John Boyer
> 
> > 
> > 
> >     L. The seconds-from-dateTime() function poses a 
> particular problem
> >     because XPath 2.0 offers a function with the same name and
> >     different semantics.
> > 
> >     You should define whether leap second are taken into 
> account, and
> >     if so, specify how.
> > 
> >