[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message]

Re: Some random noise on rational type systems for XML

• To: Joe English <jenglish@f...>
• Subject: Re: Some random noise on rational type systems for XML
• From: Uche Ogbuji <uche.ogbuji@f...>
• Date: Sat, 10 May 2003 19:16:33 -0600
• Cc: xml-dev@l...
• In-reply-to: Message from Joe English <jenglish@f...> of "Tue, 06 May 2003 18:57:53 PDT." <200305070157.h471vr912020@d...>
• Sender: uche.ogbuji@f...

> 
> John Cowan wrote:
> > Amelia A. Lewis scripsit:
> > > First principle: the XML ur-type is "string".  Everything in XML can be
>                      ^^^^^^^^^^^^^^^^^^^^^^^^^^
> > > represented as a string (MUST be representable as a string).  It can
> > > therefore be manipulated as a string--truncated, concatenated,
> > > case-transformed, etc.
> >
> > No, I have to disagree here.  Every datatype instance can be *represented*
> > by a string, right enough.  That does not mean the instance of that type
> > *is* a string.
> 
> But the _XML_ ur-type is string.  From the application
> point of view, you might have dates, integers, IEEE double
> precision floating point numbers, et cetera, but as far
> as XML is concerned everything is a string.
> 
> If we're talking about a rational type system _for XML_,
> then Amelia's first principle is eminently sensible.  In fact,
> I'd go even further and say it's the _only_ sensible foundation
> for an XML type system.

Yes, and I'd like to point out that this is the foundation that we have 
already staked out as the right approach to datatyping in XPath NG.  See 
earlier threads between Jeni, Eric and I on this list.  I also think that it 
is an approach that would fit nicely into DSDL, and I think Eric's XVIF 
provides an excellent test-bed for such ideas (which is why I was very 
grateful to do some 4-eyes-on-the-screen time with Eric looking over his 
implementation last week).

I do believe we'll get there.  Slowly, maybe, but we'll get there.

http://lists.fourthought.com/mailman/listinfo/xpath-ng
http://www.xml.com/pub/a/2003/04/30/dsdl.html
http://downloads.xmlschemata.org/python/xvif/


-- 
Uche Ogbuji                                    Fourthought, Inc.
http://uche.ogbuji.net    http://4Suite.org    http://fourthought.com
Gems From the [Python/XML] Archives - http://www.xml.com/pub/a/2003/04/09/py-xm
l.html
Introducing N-Triples - http://www-106.ibm.com/developerworks/xml/library/x-thi
nk17/index.html
Use internal references in XML vocabularies - http://www-106.ibm.com/developerw
orks/xml/library/x-tipvocab.html
EXSLT by example - http://www-106.ibm.com/developerworks/library/x-exslt.html
The worry about program wizards - http://www.adtmag.com/article.asp?id=7238
Use rdf:about and rdf:ID effectively in RDF/XML - http://www-106.ibm.com/develo
perworks/xml/library/x-tiprdfai.html

• References:
  • Re: Some random noise on rational type systems for XML
    • From: Joe English <jenglish@f...>

• Prev by Date: Re: Some random noise on rational type systems for XML
• Next by Date: Re: (data) medium is the message
• Previous by thread: Re: Some random noise on rational type systems for XML
• Next by thread: Re: Some random noise on rational type systems for XML
• Index(es):
  • Date
  • Thread