[Xpath-ng] Proposal for definition of values/lists

[Uche Ogbuji]

> Hi Jeni,
> 
> On Tue, 2002-11-26 at 15:10, Jeni Tennison wrote:
> > Hi,
> > 
> > I propose that we define values in XPath NG as follows:
> > 
> >   Every value in XPath NG is a list or an atom. A list is a sequence
> >   of zero or more values. Atoms are of two kinds: nodes and data.
> >   Nodes are atoms that have identity whereas data are atoms that do
> >   not have identity.
> .../...
> > Any comments or thoughts on the above issues? Any other issues that
> > I've glided over?
> 
> I think that we'd rather first decide if it's worth breaking the
> compatibility (even if only in terminology) with XPath 1.0 at this
> level.

I think we define a one way mapping from XPath 1.0 to XPath NG core.  I don't 
think we also need XPath NG core to run in XPath 1.0 engines.  I can imagine 
some scenarios where this would be nice, but none of them, I think, are 
critical.

It is most important for me that XPath 1.0 is close to forward compatible with 
XPath NG core.  "Close to" is fine with me.  How close is a matter of debate  
:-)


> I am not taking position or standing on one side or another, just
> raising a red flag that this is impacting backward compatibility and
> that we should explicitely document this choice and decide if XPath 1.0
> is broken enough to deserve breaking compatibility...

I think we should try very hard to be backward compatible, but no harder.


-- 
Uche Ogbuji                                    Fourthought, Inc.
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