[threeten-dev] Islamic calendar variants need disambiguation

[Dan Chiba]

Thank you Stephen. #118 is just updated. Would you review it once again 
so we can confirm it looks good to you.

Regards,
-Dan

On 1/14/2013 4:06 PM, Stephen Colebourne wrote:
> As we've discussed before, there are two parallel IDs. For example
> "Coptic" and "coptic", or "Hijrah" and "islamic". The table needs
> updating with another column for the chronology ID (essentially an
> alias based around the 310 class name). The ID isn't limited to 8
> letters, but it is probably easiest and simplest to re-use the cv
> string. Thus "Hijrah-sa" would be an alias for islamic-sa" in the
> of(String) factory method.
>
> Stephen
>
>
> On 14 January 2013 21:34, Dan Chiba<dan.chiba at oracle.com>  wrote:
>> Hi Stephen,
>>
>> Thank you for the comments. For the ambiguous cases with no cv code, let's
>> let it fall back to "islamic", which is the default variant Umm Al-Quara
>> ("ca-islamic-cv-uaq" in CLDR). I just updated github #118
>> <https://github.com/ThreeTen/threeten/issues/118>  with this information.
>>
>> For the chronology ID, I am not sure exactly what it is; is it an ID to
>> specify a Chronology class? If it could affect Islamic calendar support,
>> would you mind providing a pointer to the discussion?
>>
>> Thanks,
>> -Dan
>>
>>
>> On 1/13/2013 2:50 PM, Stephen Colebourne wrote:
>>> This plan looks fine to me,
>>>
>>> There is a separate discussion around what the chronology ID will be,
>>> currently "Hijrah" (the strings in your email are the calendar system
>>> ID).
>>>
>>> I do think that it is important that if the Locale has a ca code, but
>>> not a cv code, then it should map to something sensible.
>>>
>>> Stephen
>>>
>>>
>>>
>>> On 12 January 2013 01:35, Dan Chiba<dan.chiba at oracle.com>   wrote:
>>>> For 310, we like the approach to use "islamic" for the primary variant
>>>> and
>>>> using "islamic-xxx" for others.
>>>> We would like to propose a few details to fit to the CLDR ca/cv
>>>> separation
>>>> as follows:
>>>>
>>>>    310             CLDR                  Description
>>>>    -------------   --------------------  ---------------------------------
>>>>    islamic         ca-islamic-cv-uaq     Umm Al-Qura
>>>>    islamic-sa      ca-islamic-cv-sa      Saudi Arabia Sighting
>>>>    islamic-???     ca-islamic-cv-???     "???" denotes a specific variant.
>>>>
>>>>
>>>> * Chronology.of() takes a 310 string. In JDK8 "islamic" and "islamic-sa"
>>>> are
>>>> the only defined variants.
>>>> * Chronology.ofLocale() creates the specified variant if the locale has
>>>> the
>>>> CLDR designation inside.
>>>> * The variant identifier must be in lowerecase and can be 2 to 8 letters
>>>> long.
>>>> * The IANA region codes are reserved. A region other than "sa" may have a
>>>> variant.
>>>> * 310 and CLDR plan to identify the common variants.
>>>>     (e.g. "kuwaiti" may be in high demand and become the next defined
>>>> variant.
>>>> The list may grow.)
>>>> * Users who need a user defined variant may use a custom ID at their own
>>>> risk.
>>>>     They are encouraged to request getting the ID registered.
>>>> * 310 could have "islamic-uaq" as an alias of "islamicc" to match the
>>>> defaulting for deprecation in CLDR.
>>>> * 310 could have "islamic-uaq" as an alias of "islamic" to help achieve
>>>> consistent mapping from CLDR to 310.
>>>> * The registration/maintenance process is TBD.
>>>>
>>>> May I ask if this looks something we can settle this with?
>>>>
>>>> Regards,
>>>> -Dan
>>>>
>>>>
>>>> On 1/11/2013 2:01 PM, Stephen Colebourne wrote:
>>>>> The string can be anything you want, as its more of an Oracle
>>>>> requirement than mine.
>>>>>
>>>>> Personally, I would recommend that Oracle chooses a default Islamic
>>>>> calendar variant, so the string "islamic" maps to one of the variants.
>>>>> I would then have the other variants as "islamic-xxx". The ca and cv
>>>>> parts in the 310 calendar system id are not really relevant.
>>>>>
>>>>> Stephen
>>>>>
>>>>>
>>>>> On 11 January 2013 20:49, Dan Chiba<dan.chiba at oracle.com>    wrote:
>>>>>> Thank you very much Yoshito-san.
>>>>>>
>>>>>> Stephen, can the single string be "ca-islamic-cv-???"? Then all we need
>>>>>> to
>>>>>> do may be define the ???s?
>>>>>>
>>>>>> Regards,
>>>>>> -Dan
>>>>>>
>>>>>>
>>>>>> On 1/10/2013 5:20 PM, Stephen Colebourne wrote:
>>>>>>> On 10 January 2013 21:04,<yoshito_umaoka at us.ibm.com>     wrote:
>>>>>>>> We had a discussion about this in the CLDR TC meeting.
>>>>>>>> Our tentative consensus is supporting calendar variations with a new
>>>>>>>> extension.
>>>>>>>>
>>>>>>>> Although CLDR defines two types "islamic" and "islamicc", CLDR only
>>>>>>>> has
>>>>>>>> one set of formatting data. From formatting aspect, the difference in
>>>>>>>> date
>>>>>>>> calculation between them is not important. Our current plan is:
>>>>>>>>
>>>>>>>> 1. Add a new extension "cv" (calendar algorithm variant - tentative).
>>>>>>>> 2. Investigate necessary types from experts, based on some references
>>>>>>>> including your ticket above.
>>>>>>>> 3. Deprecate "islamicc", and map to ca-islamic-cv-??? (??? will be
>>>>>>>> determined later).
>>>>>>>>
>>>>>>>> Note that the type value is limited to 8 characters because of BCP 47
>>>>>>>> definition. We also considered multi-segment calendar type like
>>>>>>>> islamic-umalqura as you suggested in the ticket, but it will require
>>>>>>>> a
>>>>>>>> bunch of duplicated references in CLDR data formatting data. For this
>>>>>>>> reason, we are in favor of separating minor algorithm differences in
>>>>>>>> a
>>>>>>>> separate extension.
>>>>>>> FWIW, I like the "cv" variant concept as it makes logical sense. It
>>>>>>> will be harder to integrate into JSR-310 (where our methods take a
>>>>>>> single String). The lookup from a Locale object will of course pose no
>>>>>>> problem to adapt.
>>>>>>>
>>>>>>> Stephen