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

["Robert C. Leif" <rleif@rleif.com>]

From: Bob Leif
To: Georg Bauhaus et al.

My comments were specifically directed to XML schema. Therefore, the
SGML handbook is only of historical interest. 

As for floating point types or others used in calculations, it depends
who created the schema. If the schema is created by an Ada programmer,
one obvious simplification is to make the Ada and XML data types as
close as possible. As for further restricting (subtyping) of the Ada
data types, this depends entirely on the application. However, most of
the time, the simplest approach is to initially create a data type to
meet all of one's requirements. 

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

-----Original Message-----
From: comp.lang.ada-admin@ada.eu.org
[mailto:comp.lang.ada-admin@ada.eu.org] On Behalf Of Georg Bauhaus
Sent: Thursday, June 06, 2002 7:15 AM
To: comp.lang.ada@ada.eu.org
Subject: Re: XML and Ada was RE: A standard package for config files is
needed

Robert C. Leif <rleif@rleif.com> wrote:
: I think of a schema as the data types in an Ada specification. The XML
: document data has to be type compliant with the schema. A second
schema
: can make subtypes from or extend types present in an imported (withed)
: schema. I admit that I have an Ada mind set. 

Hmm, would that be more than a schema based XML syntax for the
creation of Ada syntax based definitions of the same data types?

I found this in The SGML Handbook:
"The net result of this design [data as text] is that
an application is free to define its own semantics and
the representation of its data types. The SGML parser can
guarantee that the user's specified attribute values will meet
the applications's lvength and alphabe restrictions, so they
will fit into the application's buffers and be valid input
to the application's routines that convert them to internal
representations.  The application retains the responsibility of
determining whether the converted values satisfy its semantic
constraints.[4]
 "[4] There is no intention here to suggest that standardization
of processing semantics and data type representations would
not be a good thing--only that it should not be the province
of SGML.  Introducing semantic standards into SGML would only
serve to limit the potential processing of a document, as a
single semantic standard is no more likely to be optimal for
all pllications than a single programming language."

What would be the result in case of fpt calculations, e.g.?
If, by the schemata, your data tell me to consider X as a float
with constraints Y, would there be a requirement to use these
constraints in my program? Or would I be free to add precision
by asking the compiler for a higher precision?

-- Georg