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Joe English scripsit:
> We don't need mobile code. We need a reasonable XPointer
I agree; my reference to mobile code was intended as a reductio ad absurdum.
> XPointer was supposed to solve *one* *simple* problem: how to
> locate part of an XML document and/or a specific position in
> an XML document. And yes, this _is_ a simple problem. It's
> been solved dozens of times. We just need a standardized way
> to do it.
Fine. You go and devise a method that is both maximally powerful and
trivially easy to implement. The Linking WG couldn't, so we provided
a set of tradeoffs.
> URLs provide the machinery to locate the document as a whole;
> all that was left to do was work out the details of the fragment
XPointers are *not* intended to be used solely for fragment identifiers,
though that is one very important use case.
> And yes, this is about URLs, not URIs: URIs can use
> whatever the hell they want after the # sign, since their only purpose
> is to Identify. XPointer is for people who need to Locate.
I don't understand this. "URI" means "URL or URN" -- in either case
you may end up actually fetching the resource, and if so, it makes sense
to interpret a fragment identifier.
> We don't need an extensible framework for multiple addressing
> schemes. We need *one* scheme that *works*.
> But the XPointer WG apparently couldn't agree on a single
> scheme that works, so we got an extensible framework instead.
> So fragment identifiers get a bit longer -- you have to
> say "Using scheme 'foo', locate element 'bar'" instead of
> just "locate element 'bar'".
> We don't need this, but we could live with it.
> But then it gets worse: since you have to identify scheme "foo",
> what better way, someone must have thought, than to Identify
> it with a URI? So now you have to say "Using scheme
> 'http://www.example.com/foo' locate element 'bar'" instead of
> "Using scheme 'foo' locate element 'bar'".
If you want to use a scheme that the W3C didn't standardize, yes.
> We *really* don't need this. Only a rabid URI fetishist
> would even consider embedding URIs in the fragment identifier of
> a URL --and embedding them via QNames is just insane -- but
> apparently the URI fetishists have a quorum, 'cause that's
> what we got.
Propose an alternative open system that doesn't involve creating a new
registry just for the purpose.
> And now people are talking about using the URI that Identifies
> the XPointer scheme to Locate a machine-processable definition
> of that scheme.
Only in the mode of irony. Daniel Veillard claimed that we needed
machine-processable "descriptions" of XPointer schemes in order to make
arbitrary XPointers interoperable. I pointed out that such descriptions
would in fact amount to code.
> What we need is a reasonable XPointer specification, with
> one scheme, that works.
John Cowan firstname.lastname@example.org www.ccil.org/~cowan www.reutershealth.com
"If I have seen farther than others, it is because I am surrounded by dwarves."