<i18n dev> Additional Date-Time Formats

[Joe Wang]

Hi Naoto,

Nice use of regular expression! Saves a lot of description if I would 
just follow the regex pattern.

Question:
        The 2nd and 3rd statements defined the requestedTemplate, does 
it imply the characters listed in the snippet are the only ones that are 
valid, in other words, can other characters under the Patterns section 
be used? It may be helpful to elaborate on the snippet a bit more.
        Also, the range implies a valid range for a particular symbol, 
if that's the case, y and w feel like they are unbound. If I do that 
with ofPettern, I get ArrayIndexOutOfBoundsException.

For the sample code, it might be helpful to put them in a code snippet 
and with the actual java code. If "yMMM" formats to 'Jun 2020', that 
might require some explanation too since that would be the same as 
ofPattern("MMM y") for the default(US) locale, or was it a typo?. (I'm 
not familiar with the use of DTF, just printed out 
date.format(DTF.ofPattern("yMMM" and "MMM y") :-))

Joe

On 1/24/22 4:13 PM, Naoto Sato wrote:
> Updated the CSR (https://bugs.openjdk.java.net/browse/JDK-8243445), by 
> adding a regular expression for the requested template. This way, it 
> is less depending on the LDML specification.
>
> Naoto
>
> On 1/21/22 2:39 PM, Naoto Sato wrote:
>> Thanks, Joe.
>>
>> Good point. I will elaborate the pattern template part more, less 
>> depending on the LDML spec. Would have been better if we could 
>> introduce our own, such as ofLocalizedPattern(Set<ChronoField> 
>> template), but not exactly suffices the need.
>>
>> Naoto
>>
>>
>>
>> On 1/20/22 9:52 PM, Joe Wang wrote:
>>> Hi Naoto,
>>>
>>> The javadoc points to LDML, it seems to me though it might be useful 
>>> to add more information similar to that for the ofPattern methods, 
>>> what's under the "Patterns for Formatting and Parsing" section, so 
>>> that for at least the common use cases we could rely on the javadoc 
>>> without having to consult the LDML specification. Some comparison 
>>> with the ofPattern methods might also be helpful.
>>>
>>> Just my 2 cents.
>>>
>>> Thanks,
>>> Joe
>>>
>>> On 1/20/22 1:46 PM, Naoto Sato wrote:
>>>> Hello,
>>>>
>>>> I am proposing a couple of new factory methods in 
>>>> java.time.format.DateTimeFormatter that produce flexible localized 
>>>> date/time formats, other than the existing pre-defined 
>>>> (FULL/LONG/MEDIUM/SHORT) styles. For example, if the user wants a 
>>>> year and month only string, such as the title for the calendar, 
>>>> currently they would have to use DateTimeFormatter.ofPattern() with 
>>>> explicit pattern argument, such as "MMM y". This is problematic 
>>>> because it is correct in locales such as US, but not correct in 
>>>> other locales.
>>>>
>>>> So, I propose methods that are parallel to ofPattern(), which take 
>>>> pattern template. This is based on the CLDR's skeleton: 
>>>> https://www.unicode.org/reports/tr35/tr35-dates.html#availableFormats_appendItems 
>>>>
>>>>
>>>> Detailed design can be found in the draft CSR: 
>>>> https://bugs.openjdk.java.net/browse/JDK-8243445
>>>>
>>>> Comments are welcome.
>>>>
>>>> Naoto
>>>>
>>>