Re: [calsify] SKIP was Re: AD review of draft-ietf-calext-rscale-03

[Barry Leiba <[e-mail]>]

>> I do NOT think that we need to accompany this with any list of
>> calendars.  Whoever implements a particular calendar needs to know how
>> it works in order to generate the right SKIP values anyway.  So why
>> not just say that, and forget about having to include the SKIPs?
>
> Because there should be an agreement between all implementation on what SKIP
> default is applied to a given Calendar. Say, we agree here that SKIP should
> default to BACKWARD for all calendars except HEBREW, for which it should
> default to FORWARD. This information needs to be written somewhere and set
> in stone, so that all implementation apply correct default when expanding
> RRULEs.

No, the point isn't that we should agree that SKIP defaults to
BACKWARD or FORWARD or BANANA, except for anything.  We should agree
that the way each calendar behaves in this regard is specific to each
calendar, and implementors of a particular calendar need to understand
how that calendar works and implement it right.

> Otherwise an implementor without deep knowledge of a particular calendar
> (its not required if he bases his implementation on ICU for example), can
> apply a different default. I don't see how can we do without a registry for
> variable defaults, if we choose this option.

We do this sort of thing all the time, and it works.  Do we get bad
implementations sometimes, because someone gets it wrong?  Sure.
Those usually get fixed.  I think that situation is *far* better than
having skip rules (perhaps wrong ones, created by the same buggy
implementations) imbedded in the iCalendar entries.

Barry