Re: simple case of IRIs for Components in WSDL 2.0

On Oct 12, 2005, at 6:03 PM, Pat Hayes wrote:
Arthur wrote:
>> That is not a problem in the XPointer framework since all the parens 
>> are balanced. The WSDL URI have balanced parens.
> Sorry, I was being too brief. I realize the parens are balanced within 
> the URI itself. But consider a parser which is trying to parse some 
> notation like LISP or Common Logic Interchange Format, in which the 
> parentheses are considered to be lexical break characters, and which 
> contains embedded URIs as identifiers. Then a URI with an adjacent 
> close parenthesis on the right will be quite common, as for example in 
> a text such as
> (cl:text (ex:R ex:a))

This case, in a sense, doesn't matter since no sorta-qname convention I 
know of permits it, even with a breaking space. If the last character 
of a URI is not an ncname character, then you cannot abbreviate it with 
a qname like construct. This is why RDF/XML cannot serialize all legal 
RDF graphs.

> If URIs end with closing parentheses, then such a parser will be 
> unable to disambiguate, say, the URI 'http://ex.badend/(foo)'  from 
> the concatenation of the URI 'http://ex.badend/(foo' and the closing 
> parenthesis ')'. In practice, almost certainly the latter will be what 
> is parsed, since the parser will not even seek the URI lexical form
> Of course, there are ways around this: the URIs can be enclosed in 
> protective lexical wrappings such as double quotes, for example,

URIs always must be so protected (a la NTriples) because lots of nasty 
characters (e.g., commas and quotes) can appear in a URI. As I said, 
uris with funky trailing characters can't be abreviated with Qnames 

>  or users of these languages can be required to insert whitespace 
> before a lexical-breaking parenthesis. But all such ways introduce 
> artificiality and awkwardness into what is otherwise a very natural 
> and widely used syntactic convention.

One can turn this question around and ask why we are requiring people 
to not use a composible, extensible standard (XPointer). Perhaps we 
should ping it over to Semantic Web Best Practices and see what they 
think as well?


Received on Wednesday, 12 October 2005 22:41:01 UTC