[Freeipa-devel] Proposed changes to the HBAC grammar

[Adam Young]

On 11/19/2010 06:33 AM, Stephen Gallagher wrote:
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> On 11/18/2010 06:16 PM, Dmitri Pal wrote:
>    
>> Adam Young wrote:
>>      
>>> On 11/18/2010 05:27 PM, Dmitri Pal wrote:
>>>        
>>>> Adam Young wrote:
>>>>
>>>>          
>>>>> On 11/18/2010 04:02 PM, Stephen Gallagher wrote:
>>>>> On 11/18/2010 09:55 AM, Dmitri Pal wrote:
>>>>>
>>>>>
>>>>>            
>>>>>>>> Steve can you summarize where we are and what we agreed to,
>>>>>>>>
>>>>>>>>                  
>>>>> please, and
>>>>>
>>>>>            
>>>>>>>> identify the questions that we need to answer.
>>>>>>>>
>>>>>>>>
>>>>>>>>                  
>>>>> Simo, Adam and I had a long discussion on IRC regarding the time rules
>>>>> today (complete log attached).
>>>>>
>>>>> The short version is that we're going to continue (mostly) with the
>>>>> current grammar for the time rules, with a few changes.
>>>>>
>>>>> 1) We need to replace week-of-the-month with day-of-the-septet. This
>>>>> day
>>>>> should not be a range or multi-valued to eliminate confusion
>>>>> 2) We need to replace the time range with a duration
>>>>> 3) We should add startDate and endDate as attributes on the HBAC object
>>>>> (separate from the accessTime). I propose these should be in LDAP
>>>>> generalizedTime so that it's possible to construct filters around them.
>>>>> This effectively sets the beginning and end of a periodic schedule.
>>>>>
>>>>>
>>>>>
>>>>>            
>>>>>> OK, just please stop calling it septet.  I think Drums, Bass, Piano,
>>>>>>
>>>>>>              
>>>>> 2 Saxes,  Trumpet,  Trombone Jazz combo when I hear that.  It isl ike
>>>>> octet versus byte....it means the same thing, and just annoys people.
>>>>>
>>>>>
>>>>>            
>>>>>> What you really want is to call it week-of-the-month as opposed to
>>>>>>
>>>>>>              
>>>>> week.  I realize that is more verbose, but we don't sound like
>>>>> smarty-pants.
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> I've drawn up a new grammar definition and published it to the SSSD
>>>>> wiki
>>>>> (not currently linked from anywhere):
>>>>> https://fedorahosted.org/sssd/wiki/HBAC_Grammar
>>>>>
>>>>> Please review and give feedback.
>>>>>
>>>>>
>>>>>
>>>>>            
>>>> I thought that first septet is the first seven days of the month based
>>>> on earlier mails from Steven. Is this a true statement?
>>>> The whole issue started with ambiguity of the notion of the "N-th week"
>>>> of the month.
>>>> What is it the week-of-the-month? Is it first seven day regardless what
>>>> day of the week is the first day of the month (this is what I thought a
>>>> septet is) or fist full week from Monday to Sunday or from Sunday to
>>>> Saturday, or it is the first usually partial week? This is the ambiguity
>>>> that we want to avoid!
>>>>
>>>> If the septet is what I think it is then we can't name it the
>>>> week-of-the-month and IMO septet is a good term here. However then there
>>>> is a bug in grammar as septet can be only 1-5 not 1-6.
>>>>
>>>>          
>>> OK, if this is really what is driving the grammar, I'm going to have
>>> to NACK.
>>>
>>> Lets make something that is intelligible.  We don't want to be
>>> inventing concepts like Septet.  Or Septave, since 8 days is already
>>> called an octave.
>>>
>>> Here's the Cron line that Steve posted before.  It represents   THe
>>> first wednesday of the month.
>>>
>>> 0 8 1-7 * 3
>>>
>>>
>>> Lets keep the concept of week, starting on Sunday, add in the concept
>>> of day of the month, and mix the two together.
>>>
>>> Does the current grammar (pre-septet) support that?  Something like:
>>>
>>> accessTime: periodic monthly between day 1-7  wednesday
>>>
>>>        
> No, it does not. That's the specific reason for introducing septet, to
> add this support. However, you make an interesting point. Perhaps we
> could introduce a more generic term than septet to allow the above.
>
> Though I think user comprehension would be made easier if we turned the
> construct into something closer to:
>
> accessTime: periodic monthly Wed between day 1-7
>
>
> Though for the parser, I think it would be best to have a delimiter
> between Monthly and Wed. I'm open to suggestions for what makes sense,
> though. "encompass"? "inclusive"? "position"?
>    

'on'?

>    
>>>        
>> It does not support this.
>> It requires to specify either a week of the month after "monthly" and
>> then day within a week (as numbers or the letter day names) or a set of
>> numbers representing days or ranges of ways with thin the month.
>> You can't with exiting schema unambiguously define "first Wednesday of
>> the month" without the proposed "septet" changes.
>>
>>      
>
> - -- 
> Stephen Gallagher
> RHCE 804006346421761
>
> Delivering value year after year.
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