[threeten-dev] Review Lenient parsing of 2 and 4 digits values (years)

[roger riggs]

Hi Sherman,

Yes, I missed updating some of the javadoc comments.

To work effectively the reducedValue mechanism should be associated with
the "yy" patterns but the default is strict.  It seemed important to be 
able to leverage
the locale specific date pattern info for the ordering and separators
of the fields.    I suppose the question is whether this kind of leniency
is a reasonable interpretation or usage within the CLDR descriptions.

Expanding the definition of the reducedValue seemed like a reasonable
extension.

Roger


On 4/19/2013 3:20 PM, Xueming Shen wrote:
> I'm a little concerned of the approach of using the reducedValue 
> parsing/lenient
> mode to address this 2 and 4 digits values issues, especially it 
> introduces in the
> "uncertainty of" adding the baseValue or not based on the width of the 
> input value,
> while the method itself is originally designed to add the baseValue 
> for a "reduced"
> input. There is also words later says "This is a fixed width parser 
> operating using
> 'adjacent value parsing'...", anything need to be wording here?
>
> -Sherman
>
> On 04/19/2013 11:26 AM, roger riggs wrote:
>> Hi,
>>
>> As noted in#218 Parsing 2 and 4 digit years 
>> <https://github.com/ThreeTen/threeten/issues/218>, the reducedValue 
>> parsing
>> lenient mode should be defined to allow parsing of absolute values
>> greater than the defined field width.
>>
>> Webrev:
>>    http://cr.openjdk.java.net/~rriggs/webrev-lenient-parse-218/
>>
>> Modified DateTimeFormatter.appendValueReduced to define the behavior 
>> when isLenient.
>>
>> Modified NumberPrinterParser in lenient mode to accept 1..19 digits.
>> Note, the API/ implementation only works for base < MAX_INT, ~ 10 digits
>> but the field size may be defined larger.
>> Removed width constraint for "fixed" fields unless strict.
>>
>> Modified ReducedPrinterParser.setValue to apply the base only
>> if isStrict or the value is less than range.
>>
>> It is not possible to enter negative values since ReducedPrinterParser
>> prohibits any sign character.  It should be considered to make the
>> sign parsing lenient also.  Currently entering a sign is prohibited 
>> in a "fixed"
>> length field. The definition of fixed is diluted in this case in 
>> lenient mode.
>>
>> It is also not possible to enter absolute values less than the width.
>> All small values are considered to be combined with the base.
>> The only interesting case though is year and the range of likely base
>> values is the current or past centuries.
>>
>> Thanks, Roger
>>
>