XOM API for Processing XML with Java

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

At 10:29 AM -0400 10/10/02, John Cowan wrote:


> On the contrary, I think everyone is now striving to avoid them.  The main
> reason they weren't just made illegal is that Microsoft had deployed tools
> that generated them (in order to create document-local namespaces), and
> some unknown number of documents already contained them.  I very much doubt
> whether this practice is spreading, though: people are switching to urn:uuid:
> or other schemes that make uniqueness straightforward.

I'm going to try that this weekend and see if anyone yells. :-)

> >  The second more practical and probably solvable question is how one
> >  identifies an absolute URI.
>
> A URI is absolute iff it matches this regular expression:
>
>         ^[A-Za-z][A-Za-z0-9+.-]*:
>
> See the productions "absoluteURI" and "scheme" in RFC 2396.

There's a bit more than that. The characters after the colon all have 
to be legal URI characters, and any percent signs have to be followed 
by exactly two hexadecimal digits.

> >  The stumbling block is I can't decide if URIs containing multiple
> >  colons are legal; e.g. is urn:publicid:foo::bar OK?

Yes, I think I've finally got this straightened out. The most helpful 
part was discovering Appendix A where the entire BNF grammar is in 
one place in the spec so I didn't have to keep flipping back and 
forth between pages. :-)
--

+-----------------------+------------------------+-------------------+
| Elliotte Rusty Harold | elharo AT metalab.unc.edu | Writer/Programmer |
+-----------------------+------------------------+-------------------+
|          XML in a  Nutshell, 2nd Edition (O'Reilly, 2002)          |
|              http://www.cafeconleche.org/books/xian2/              |
|  http://www.amazon.com/exec/obidos/ISBN%3D0596002920/cafeaulaitA/  |
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