Re: XPath 1.0 or 2.0

/ Alex Milowski <alex@milowski.org> was heard to say:
| Here's a proposal:
|
|   * if you specify an XPath version, you are declaring an
|     explicit requirement.
|   * implementations are allowed to provide XPath 2.0 or
|     other future versions.
|   * if you specify an earlier version (e.g. 1.0) when
|     a later version is available, there is already a well-defined
|     compatibility between the versions (see the XPath 2.0
|     spec for that).

So you're suggesting that not only should we foster an
interoperability problem with this difference, but that we should
exacerbate the problem by allowing implementations to evaluate 1.0
expressions with a 2.0 processor in backwards compatibility mode?

|   * implementations should/must warn users when they use
|     a different version than what the author of the pipeline
|     specified.

It's pointless to attempt to specify warnings. It's simply not
practical for some implementations to issue them, they don't
necessarily go where the user can see them, and implementations are
free to issue any warnings they want without our permission.

|   * if you don't specify the version of XPath, it defaults
|     to the version specified by the pipeline language
|     version--which would be 1.0 for our first version.
|
| An optional feature would be the "halt and catch fire" option
| for when the XPath version doesn't match.  I'm not sure that
| is a good idea since there is already a compatibility story
| for what happens to XPath 1.0 expressions in XPath 2.0.

                                        Be seeing you,
                                          norm

-- 
Norman Walsh
XML Standards Architect
Sun Microsystems, Inc.