Protocol-08 (and status of Defs-04 and Rationale-06)

[Eric Brunner-Williams]

I'm concerned that the proposed rules are overly broad, if a label can 
be 63 characters, and the claim is that no two of them can have 
properties A and B, where one has property A and one has property B, 
then is the proposed rule true for some positional possibilities, but 
not all, or true for all.

If all, then the rule is minimal. If only some, then it would be nice, 
at least, to be able to describe, and algorithmically would be really 
nice, the set(s) for which the rule is correct, and the set(s) for which 
the rule is incorrect.

I'm happy to continue this off-list, as my original, and similar query 
about rule 4 didn't get to "what do we know and how do we know it".

Eric

Erik van der Poel wrote:
> All of the bidi rules, including rule 4, have been tested by Harald
> and myself. Admittedly, Harald was the one who came up with the rules,
> but I tested all of the rules, by removing one, running the program,
> finding the problem, reinserting that rule, removing the next rule,
> and so on. In other words, not one of the rules can be removed at this
> point.
>
> It might be possible to change the rules and find a different set of
> rules where not one of them can be removed, but at this point in time,
> I don't know whether it's worth it. (Unless someone can come up with
> character sequences that are really needed or highly desirable that
> fall afoul of the current rules.)
>
> Erik
>
> On Tue, Dec 9, 2008 at 7:20 AM, Eric Brunner-Williams
> <ebw at abenaki.wabanaki.net> wrote:
>   
>> Thank you. Earlier I asked someone else about rule 4. The response was not
>> so informative, could I trouble you to answer the rational question for that
>> rule also?
>>
>> Eric
>>
>> Erik van der Poel wrote:
>>     
>>> Harald and I did exhaustive tests using two different implementations
>>> of the bidi algorithm (he used his own, I used ICU for C/C++). We
>>> found that without that rule, you'd get the kind of behavior that we
>>> don't want. See Label Uniqueness and Character Grouping in:
>>>
>>> http://tools.ietf.org/html/draft-ietf-idnabis-bidi-03#section-3
>>>
>>> Erik
>>>
>>> On Tue, Dec 9, 2008 at 6:37 AM, Eric Brunner-Williams
>>> <ebw at abenaki.wabanaki.net> wrote:
>>>
>>>       
>>>> Harald Alvestrand wrote:
>>>>
>>>>         
>>>>> Eric Brunner-Williams wrote:
>>>>>
>>>>>           
>>>>>>>          Alright, that is what has been proposed so far. *But* we
>>>>>>> now need
>>>>>>> to take into account Harald's reminder that some combinations
>>>>>>> are already disallowed separately by the bidi rules on label
>>>>>>> well-formedness, quite independently of any consideration of
>>>>>>> CONTEXTO categorization. What the bidi rules require of label
>>>>>>> formation is:
>>>>>>>
>>>>>>> Bidi:     Forbid (d) and (f) [and (g) by corollary]. Allow (e).
>>>>>>>
>>>>>>>
>>>>>>>               
>>>>>> Could you point out the lines in bidi you are referring to here?
>>>>>>
>>>>>>
>>>>>>
>>>>>>             
>>>>> Section 2 rule 5:
>>>>>
>>>>>  5.  If an EN is present, no AN may be present, and vice versa.
>>>>>
>>>>>
>>>>>                     Harald
>>>>>
>>>>>           
>>>> Thank you. I thought that was the case. Now where is the rational for
>>>> the rule?
>>>>
>>>> Eric
>>>> _______________________________________________
>>>> Idna-update mailing list
>>>> Idna-update at alvestrand.no
>>>> http://www.alvestrand.no/mailman/listinfo/idna-update
>>>>
>>>>
>>>>         
>>>
>>>       
>
>
>