Subject: Re: Recurrence rule clarification

From: [email-masked]
Date: Thu, 1 Jun 2000 21:47:02 -0400

Eric consoled me with:
>Well, it isn't unparsable, but it is not pretty.

Ok, "unparsable" is the wrong term.  I should have used "illogical" or 
"un-unwindable" since there is not a likely chance that a recurrence 
engine would know which FREQ go with which INTERVAL or other recur rule 
parts...

>My code that splits
>values based on commas has a special case for recur: it is a value
>separating comma only if it is followed by "FREQ." Since "FREQ" must be
>the first thing in a rrule ( contrary to some RFC2446 examples ) this
>should always work.

Better be careful there.  I know the ABNF starts with:

     recur      = "FREQ"=freq *(

but the first paragraph of the Description clearly says:

                                           The rule parts are not
   ordered in any particular sequence.

So, if you believe the intro text under 1.0 that says:

                                      This ABNF is required for
   the implementation of parsers and to serve as the definitive
   reference when ambiguities or questions arise in interpreting the
   descriptive prose definition of the memo.

then you _should_ be ok.  Its MUCH simpler in the long run if we just 
restrict the recurrence rule data type to ALWAYS be single valued...  I 
cant think of any reason that a 'double' RRULE could not just be simply 
written as 2 separate RRULEs.  I admire your approach but I prefer my gray 
cells functioning rather than smoking.

Bruce
===========================================================================
Bruce Kahn                                INet: [email-masked]
Iris Associates                          Phone: 978.392.5335
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---

From: [email-masked]
Date: Mon, 12 Jun 2000 11:36:02 -0400

About multiple recurrence rules in one RRULE or EXRULE...
I think that this should be changed to make it disallowed. The only way we 
should allow multiple recurrence or exception rules is with multiple RRULE 
or EXRULE properties. 
It would seem that the parser for multiple rules can be simplified greatly 
if we restrict in such a manner.
-- Frank