Re: Adding types to XPath

[Matt Sergeant <matt@sergeant.org>]

On Sat, 24 Feb 2001, Christopher R. Maden wrote:

> At 11:03 24-02-2001, Matt Sergeant wrote:
> >I've been following discussions about the plans for XPath 2.0 (and XSLT
> >2.0) with interest. One thing that concerns me is that in order to
> >implement XPath 2.0 I have to implement the PSVI, and thus W3C Schemas.
> 
> In some sense, but if a schema is never applied, then your PSVI will only 
> use the primitive types defined by XML 1.0.

If a schema is never applied, you don't *have* a PSVI. :-) I agree with
Rick Jelliffe, by the way, that PSVI needs to be renamed.

> In other words, you shouldn't 
> need to change your data model at all.

True, but I'd like the option of having the nice new features of XPath 2.0
(e.g. any() and all()), and no PSVI/types. Or both at my discretion. The
point being "do the minimum work required". This doesn't seem to me to
require changes to the underlying XPath syntax, which is what I fear will
happen, and wish to prevent if possible. If it is done through a function,
then its simple enough to implement or not implement. (note that the
namespace properties can also be accessed this way, so it would follow the
same design pattern used there).

> Now, some stylesheets that require 
> type matching to work might not work in your engine, but people choosing to 
> use your (presumably) lighter-weight XPath engine would, I hope, be aware 
> of that limitation.

You would hope so :-)

Also note that I don't object to having a working implementation of W3C
Schemas on my platform (except for political reasons), I only wish to keep
XPath as clean as I think 1.0 is.

Matt.