Re: relative uri references

Boris,

did we ever consider adding a 'base', like 'xml:base', to the functional
and the m'ter syntaxes?

Note that this is the only difference, for example, between the turtle
specification as a team submission[1] and the earlier turtle
specification: the former introduced a @base directive (alongside the
@prefix ones). It might make sense to do this for the FS and M'Ter.

Just a thought

Ivan



[1] http://www.w3.org/TeamSubmission/turtle/

Boris Motik wrote:
> Hello,
> 
>  
> 
> In the RDF syntax, the resolution of URI references is governed fully by
> the underlying RDF format. For example, if you are working with RDF/XML,
> then the RDF parser should use xml:base. In addition, the XML parser
> will expand any XML entities as well. There is no equivalent of the
> Namespace declaration in the RDF syntax.
> 
>  
> 
> In the XML Syntax, there are no Namespace declarations either. Again,
> you have is xsd:base for relative URIs, and this is explicitly mentioned
> in the document. Furthermore, we don’t need a specific URI abbreviation
> mechanism is because XML Syntax ontology documents can use XML entities
> for abbreviation of long URIs.
> 
>  
> 
> The functional-style syntax and the Manchester syntax, in contrast,
> cannot rely on other specifications (such as RDF of XML) for
> abbreviation and expansion of URI references, so they need their own URI
> resolution mechanisms. In the functional-style syntax ontology
> documents, only namespace declarations are expanded, and relative URIs
> are not expanded. I think this is correct: we never say that the URIs of
> ontology entities must be absolute. Thus, if someone actually creates
> ontology entities with relative URIs, the functional-style syntax will
> correctly capture this.
> 
>  
> 
> Note that URIs have a well-defined identity. Therefore, a relative URI
> provides a perfect way of identifying some ontology entity – that is, it
> is a URI just like any other.
> 
>  
> 
> Hence, it seems to me that we don’t really need to say anything more
> than what we’ve already said. We might only introduce additional
> clarification into the XML Syntax document about relative URIs: we might
> say that if you want to store such URIs, then you should explicitly turn
> xml:base off on the element whether you are doing so; otherwise, your
> relative URIs will accidentally be resolved against the xml:base and
> that wopuld lead to problems. You can turn this resolution off by
> placing on the element an xml:base with some opaque URI.
> 
>  
> 
> Regards,
> 
>  
> 
>             Boris
> 
>  
> 
> ------------------------------------------------------------------------
> 
> *From:* public-owl-wg-request@w3.org
> [mailto:public-owl-wg-request@w3.org] *On Behalf Of *Alan Ruttenberg
> *Sent:* 24 November 2008 06:05
> *To:* W3C OWL Working Group
> *Subject:* relative uri references
> 
>  
> 
> Do we not  have to say how these are resolved in the functional and
> manchester syntax, and might it not be best to explicitly say so for all
> syntaxes? 
> 
>  
> 
> -Alan
> 

-- 

Ivan Herman, W3C Semantic Web Activity Lead
Home: http://www.w3.org/People/Ivan/
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