<i18n dev> RFR: 6228794: java.text.ChoiceFormat pattern behavior is not well documented. [v2]

[Naoto Sato]

On Thu, 7 Sep 2023 17:18:33 GMT, Justin Lu <jlu at openjdk.org> wrote:

>> src/java.base/share/classes/java/text/ChoiceFormat.java line 136:
>> 
>>> 134:  *         Limit Relation Format
>>> 135:  * <i>Limit:</i>
>>> 136:  *         {@code String} that can be parsed as a {@code double} / "∞" ({@code U+221E}) / "-∞" (-{@code U+221E}).
>> 
>> Could the first choice be more specific? Also, do `SubPattern`s need to be sorted with `Limit`s?
>
>> Could the first choice be more specific?
> 
> Updated with a more syntactical definition. Please let me know if you think this is _too_ specific.
> 
>> Also, do SubPatterns need to be sorted with Limits?
> 
> If I am interpreting the question right, you're asking if a subPattern **needs** a limit to be valid. If that's the question, the answer is yes, `ChoiceFormat` is designed to have an equal amount of limits and formats (whether from the arrays, or the String pattern). But please let me know if I misinterpreted the question.
> 
> subpattern "xyz" where both _limit_ and _relation_ are omitted
> 
> jshell> var a = new ChoiceFormat("0#abc|xyz")
> a ==> java.text.ChoiceFormat at 17863
> jshell> a.getLimits()
> $21 ==> double[1] { 0.0 }
> jshell> a.getFormats()
> $22 ==> String[1] { "abc" }
> 
> 
> subpattern "#xyz" where _limit_ is omitted
> 
> jshell> var b = new ChoiceFormat("0#abc|#xyz")
> |  Exception java.lang.IllegalArgumentException: Each interval must contain a number before a format

Please let me know if you think this is too specific.

I think the updated one is better.
For the second part, I meant:

jshell> new ChoiceFormat("0#def|-1#abc|xyz")
|  Exception java.lang.IllegalArgumentException: Incorrect order of intervals, must be in ascending order

This should be excluded from the pattern syntax

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PR Review Comment: https://git.openjdk.org/jdk/pull/15392#discussion_r1319041104