Re: Grammar question

Geoff Chappell wrote:
> In the latest grammar VarOrTerm includes empty lists and empty blank nodes
> but does not include lists with content (Collection) or blank nodes with
> content (BlankNodePropertyList). Everywhere that VarOrTerm is used also
> offers alternatives using Collection and BlankNodePropertyList (except
> Reification - is that a mistake?).

Sort of a mistake (and already corrected BTW - just hasn't made the editor's 
draft yet).  Reification triples with unusual objects wasn't in the design 
space for syntax help.  [Bonus points if you can think of a reason why one 
would want to write some of the strange forms possible but that is what you 
get from recusive definitions].

The reificaton syntax is for convenience - the app can always write it out 
long hand in triples and some strange forms may be inexpressible in the 
short form (c.f. qnames and URIs - not all URIs can be appreviated).

The grammar you are looking at is very new - there will be a period of 
settling down and better expression of the syntax.  There will also be text 
in the document giving a introduction to the syntax.

> So why not just make RDFTerm include
> lists with content, blank nodes with content, and reifications - e.g. like
> the unused AnyNode? (sort of like saying that you can use a noun phrase
> anywhere you can use a noun.) Seems like it would simplify the grammar plus
> avoid potential mistakes of omission (e.g. shouldn't reification be included
> in CollectionElement?). Or is there a necessary distinction that I'm
> missing?

Only the one you noted in the next message.


> Geoff

Received on Sunday, 13 March 2005 18:05:17 UTC