[Versa] function objects

[Chimezie Ogbuji]

On and off (mostly) this topic I have some questions about the current
proposed EBNF.  In particular, have we decided if we would be able to
fit the use of RDF properties as qname functions in our current model
for anonymous functions, and first class functions?  I really do think
it's a good idea and I'm not sure if it made it into the EBNF from
what I gather - or if it even needs to be as long as the specification
states that the parser should be aware that function references may be
to functions that don't exist, in which case they should be treated as
predicate operators (as described here:
http://lists.fourthought.com/pipermail/versa/2005-September/000099.html)

Also, I'm not quite clear on the use of { } (from the recent exchange
between Mike and Uche) on how it would be used in filter expressions. 
Its use as a way to express subgraphs/contexts/scopes is clear (mostly
from Notation 3), but it's use as a 'filter expression' isn't or why
it's even neccessary at all.  Originally, I understood it as a way to
avoid the nastiness of escaping strings of expressions passed to
functions like map/distribute, but with the ability to pass references
to anonymous functions, I don't follow the usecase for them anymore.

Chimezie