Re: XML and Ada was RE: A standard package for config files is needed

[Georg Bauhaus <sb463ba@l1-hrz.uni-duisburg.de>]

Robert C. Leif <rleif@rleif.com> wrote:
: My comments were specifically directed to XML schema. Therefore, the
: SGML handbook is only of historical interest. 

Uhm, I think this is a misunderstanding (and a big one :-).
(The SGML Handbook, for those who haven't seen it, is much
like the combination of the Ada Annotated RM + Rationale,
with respect to ISO 8879 (SGML).)

XML ist still just a subset of SGML, and schema definitions 
can (therefore) be expressed in SGML, but they need not even
be expressed in XML. More importantly (and this
is why I've found the quote interesting): some of the intentions
behind schemas (more semantic information about document data
element types) are not an entirely new argument. (The author (Goldfarb)
is, I think you know, one of the two authors of The XML Handbook.)

: If I obtain an XML schema that has not been strongly typed, wherever
: possible, I create the equivalent of Ada subtypes with explicit ranges. 

This is what I wanted to point out in the quote. While I agree
that it would be nice, if at all possible, to have a consensually
defined data type (using a schema expressed in XML) independent
of a programming language, I would want this as part of the
minimal requirements section of some document, and then use the
best language techniques to implement software fulfilling these
requirements.

-- Georg