[lextypes] DLL proof of concept

[John Cowan]

Bob Foster scripsit:

> > In present practice this would mean providing an RNG datatype library interface.
> 
> Maybe a Schematron implementation is possible, too? An XML Schema
> implementation couldn't pass the test. (It is not even possible at the
> moment to translate a DTLL definition of the XML Schema datatypes into XML
> Schema unless there were a way to associate DTLL parameter names, which have
> no intrinsic meaning, with facets.)

There wouldn't be much point, either.  XML Schema is not about extensible
datatypes.  You could probably compile DTLL into a module you could
plug into a Schematron schema somehow or other, but it's not obvious to me how.

> > > - A language-independent API

The datatypes.sf.net API is language-independent in effect, though it's
specified in Java terms -- it doesn't depend on Java-specific features in
any way.

> > >specification and an implementation in one or
> > > more existing programming languages that allows, at a minimum, an
> > > application to ask, for any string value, whether it is a valid instance
> > > of a given datatype, and if so, to obtain the parse result.

This is a subset of the RNG datatypes specification, and IMHO too weak;
you need value comparison as well.  I'd like to see the RNG version could
be extended to allow datatypes to say they are magnitudes, and to permit
comparison by magnitude.  That way we can ask if integer "5" < integer
"10" and be told yes.

> > > The API should
 > > > be able to operate independent of validation.

No problem there.

-- 
All Norstrilians knew what laughter was:        John Cowan
it was "pleasurable corrigible malfunction".    http://www.reutershealth.com
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