Subject: Re: Predicates in SLP vs. LDAP

From: James Kempf <[email-masked]>
Date: Wed, 2 Aug 2000 15:56:42 -0400

Given the restricted set of LDAP logical operators that SLP supports, I can't see
an instance where a predicate would ever evaluate to undefined. I think that
only covers user defined operators, which we don't have in SLP.

But if you have an example, please post it.

		jak
>
> According to RFC 2608: 
>
>"An incoming request term MUST have the same type as the attribute in a
>registration in order to match".
>
>I assume this to be a simple TRUE/FALSE pairing, but according to the LDAP
>RFC (2251):
>
>"a filter is evaluated to either "TRUE", "FALSE" or "Undefined""
>
> The only impact of the "Undefined" value that springs immediately to
>(my) mind is how greedy the SA/DA is in matching: should a match occur on
>Undefined and TRUE, or only TRUE?
>
>
>e
>

---

From: Evan Hughes <[email-masked]>
Date: Wed, 2 Aug 2000 17:01:21 -0400 (EDT)

On Wed, 2 Aug 2000, James Kempf wrote:
> Given the restricted set of LDAP logical operators that SLP supports,
> I can't see an instance where a predicate would ever evaluate to
> undefined. I think that only covers user defined operators, which we
> don't have in SLP.
> 

   I was thinking of performing a non-presence operation on a tag that
doesn't exist. According to LDAPv3, this should result in an Undefined
(which, for boolean searches is treated as a false). I don't beleive RFC
2608 counters this. This only matters in a simple search such as
"(tree<=forest)", where value is directly returned to the UA/SA. 

  Since I've just implemented a search filter that has only boolean
values, I think that such situations should be treated as a false. =)

e