Re: [xml-dev] what's missing in XML? What's coming?

[John Cowan <cowan@mercury.ccil.org>]

Henri Sivonen scripsit:

> > 2) Clearer story on how to use the ISO/MathML entity sets along with XML
> > Schemas, or with no schemas. I often hear "XML Schemas does not support
> > entities, so I cannot use entities with XML Schemas" or vice versa.
> > Preferably, build the default mappings of the entities into XML.
> 
> Adding entities to XML without DTDs would break the compatibility of
> new documents with old parsers. I think entities alone are not worth
> such a discontinuity.

Not if it's done at the character encoding level.  The proposed utf-8+names
encoding provides for that: see http://www.tbray.org/tag/utf-8+names.html .
Basically the idea is that while the bytes 26 73 69 67 6D 61 3B encode
the corresponding Unicode codepoints in the utf-8 encoding, in the
utf-8+names encoding they encode U+03C3 GREEK SMALL LETTER SIGMA.
Of course, so does CF 83.

However, 26 66 6F 6F 3B encodes the corresponding Unicode codepoints,
as does 26 6C 74 3B.  If you need U+0026 in a context other than an
entity reference, you encode it as 26 26 3B.

Totally XML-conformant, and any XML processor can implement it if it
wants to.  Then it's just a matter of putting a correct XML declaration
on your documents.  You don't even need your editor to implement the
encoding: a regular UTF-8 editor is fine.

-- 
Real FORTRAN programmers can program FORTRAN    John Cowan
in any language.  --Ed Post                     cowan@ccil.org