- From: Jonathan Borden <jonathan@openhealth.org>
- Date: Mon, 15 Jul 2002 09:23:43 -0400
- To: <www-rdf-comments@w3.org>
see end for comments most appropriate to RDF ----- Original Message ----- From: "Jonathan Borden" <jonathan@openhealth.org> To: "Drew McDermott" <drew.mcdermott@yale.edu>; <www-rdf-logic@w3.org> Sent: Monday, July 15, 2002 9:21 AM Subject: Re: Input sought on datatyping tradeoff > Drew McDermott wrote: > > > > > I know it is futile to make the point at this late date, but the whole > > farcical question stems from the fact that RDF (and XML, and SGML, the > > whole ridiculous lineage) have no syntax for string literals. If > > everything is a string, then nothing is a string. The problem could > > be solved very simply if every literal found in an RDF file belonged to > > at most one literal class (some apparent literals being ill-formed, > > and hence not belonging to any). That would require strings to be > > indicated in some explicit way. Hey, about quotes? > > I understand your arguments but you are not giving SGML nor XML a fair > evaluation. > > SGML has mandatory schema (called DTD) which is capable of assigning > unabmiguous datatypes to essentially every syntactic structure ... such > facilities are called NOTATIONs, Groves as well as an ability to specify > delimiter characters (e.g. '<' and '>' are not intrinsically 'special' as > far as SGML is concerned). > > SGML has had success in specifying precise documentation systems at very > high expense for very large customers. XML was conceived as an attempt to > _simplify_ SGML for mass market use and to some extent it has succeeded > (mass market use, but not simplification :-)) > > So there are lots of facilities in both SGML and XML that have not achieved > widespread use (e.g. NOTATIONS). > > Now XML Schema has been introduced to 'make up' for the shortcomings of XML > in regard to datatypes in the absense of NOTATIONs and DTDs. > > If one _requires_ an XML Schema (or a RELAXNG schema for that matter), one > can simply and unambiguously have _datatypes_ in XML documents. Such > datatypes are delimited by markup not quotes -- no biggie. > > e.g. > > <ex:foo xsi:type="xsd:integer">10</ex:foo> > > Now you may not like the syntax, nor like XML Schema, but let's not argue > about that because it is _another argument_. The _problem_ is not that XML > has ambiguous syntax rather that _the type of XML_ that RDF uses does not > adequately provide for such syntax. Namely RDF and XML Schema are not > entirely compatible, e.g. it is not possible to write a complete RDF syntax > specification using XML Schema etc. > > ... > > > > Only because of XML absurdity, which has carried over to N3. > ... > > > > I'm sorry to indulge in a bit of sarcasm here and there, but the > > persistent desire of the Web community to shoot itself in the foot > > over this issue, nay, saw its foot off inch by bloody inch, baffles > > me. > > Well, the problem is that _different parts_ of the Web community are going > off and doing incompatible things, e.g. the 'solution' that XML Schema has > come up with is not entirely compatible with RDF, and there are many many > other examples of such issues. But that is life I suppose. > > I suggest that RDF drop this issue for the moment, because a _proper > treatment_ will likely require changes to the RDF syntax (as Drew points > out) which would be most appropriately done in RDF 2 (during which RDF 2 and > XML Schema 2 could be properly aligned for example) > > Jonathan > >
Received on Monday, 15 July 2002 09:38:38 UTC