[Versa] function objects

[Michael Olson]

> On Wed, 2005-09-21 at 19:58 -0600, Michael Olson wrote:
>> To revisit this, I like the idea, but syntactically I think we need a
>> symbol to differentiate these from a qname pattern.  There is no
>> difference, from the grammars POV between
>>
>> ground(rdf:type)
>>
>> and
>>
>> map(ns:func_name)
>>
>> Maybe kinda C'ish and make it
>>
>> map (&ns:func_name)
>>
>> thoughts?
>
> I guess in my thinking of this as a simple function there was no need  
> to
> distinguish between the argument to ground.  The argument is just a
> resource URI, expressed literally, or in qname form.  I would therefore
> expect to be able to do:
>
> ground(uri("http://" + "example" + ".org"))
>
> Assuming that we have a conversion function uri() in Versa 2.0 that can
> convert strings (and other data types?) to a URI.
>
> Short answer, I'd expect it to be
>
> ground(rdf:type)
>
> Maybe I'm missing something?
>

I guess I asked the question poorly.  I'm OK with how ground works in  
the example, what I think we need is a symbol to distinguish a  
qname-pattern from a function-reference in the grammar because the  
grammar cannot tell the difference between

rdf:type

which, as a writer of a query, probably means a qname pattern, and

versa:ground

which, as a writer of a query, most likely means a function-references.

What I propose is not change anything about the qname-pattern, but add  
the symbol "&" to the front of function-references so the last example  
would be

&versa:ground

Mike


>
> --  
> Uche Ogbuji                               Fourthought, Inc.
> http://uche.ogbuji.net                    http://fourthought.com
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Mike Olson                                                Principal  
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