RE: [xacml] Function Document Issues

[Daniel Engovatov <dengovatov@crosslogix.com>]

2. "and" and "or", "n-of" functions. I think they are unnecessary in
   contrast to their "ordered-*" counterparts. Since we are now
   paying explicit attention to ERROR when evaluating policy, I think we
   should just go with the "ordered" versions of these functions for
   explicitly determinate results.

Agree on "and" and "or" - should just leave ordered ones (or, rather,
rename them to be "and" and "or"

"n-of" is a different thing - does not have an alternative - and does not
suffer
from the current "or"/"and" indeterminate result - due to indeterminate 
evaluation order - issue..



3. What is the type of an argument to the function "present".
   What does it look like?  Someone please give me an example.


The same one that goes into "AttributeId" xml atribute of the <*Designator>
element.

This means

if 
	<EnvironmentAttributeDesignator
AttributeId="urn:oasis:names:tc:xacml:env:date"
					DataType="xs:date"/>
will return a non-emty sequence if evaluated

then

<Apply FunctionId="function:present">
<AttributeValue
DataType="xsi:anyURI">urn:oasis:names:tc:xacml:env:date</AttributeValue>
</Apply>

should return "true"

It would return false if the environment portion of context has no idea what
"date" is.