XOM API for Processing XML with Java

[Elliotte Rusty Harold <elharo AT metalab.unc.edu>]

At 1:29 PM -0700 10/9/02, Michael Fitzgerald wrote:
> I was thinking mostly of how relative URIs have been deprecated for
> namespace names.
>
> http://www.w3.org/XML/xml-names-19990114-errata#NE04

Yes. I'm aware of that. I'm just not sure whether or not I should 
enforce that in XOM. Though deprecated, relative namespace URIs are 
legal, and are used. One of the reasons decision on this point was so 
tough to reach and so weak in the end was that different groups were 
going in different directions on both the meaning and use of relative 
URIs for namespace names. This is an open question and more feedback 
is appreciated.

The second more practical and probably solvable question is how one 
identifies an absolute URI. Answering this question is necessary for 
canonical XML, which requires an exception to be thrown on 
encountering a relative namespace URI, even if not for XOM in general.

Near as I can tell from RFC 2396, an absolute URI must satisfy the 
following grammar:

<scheme>:<scheme-specific-part>
scheme = alpha *( alpha | digit | "+" | "-" | "." )

The stumbling block is I can't decide if URIs containing multiple 
colons are legal; e.g. is urn:publicid:foo::bar OK?  My reading of 
the spec says this is not legal because the colon is used for a 
non-reserved purpose, but I've seen things like this out there.
--

+-----------------------+------------------------+-------------------+
| Elliotte Rusty Harold | elharo AT metalab.unc.edu | Writer/Programmer |
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|          XML in a  Nutshell, 2nd Edition (O'Reilly, 2002)          |
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