On Mon, 19 May 2025 23:41:25 GMT, Naoto Sato <[email protected]> wrote:
>> It is not clear that `Locale.Builder.setLanguageTag(String)` accepts
>> _extlang_ subtags in the input as well as what behavior occurs.
>> Additionally, both this method and `Locale.forLanguageTag(String)` should
>> mention their behavior when more than three _extlang_ subtags are provided.
>> This PR clarifies the lack of context in the specification.
>
> src/java.base/share/classes/java/util/Locale.java line 2792:
>
>> 2790: * tag). {@code languageTag} may contain up to three extlang
>> subtags.
>> 2791: + For such occurrences, the first extlang subtag is used as
>> the language,
>> 2792: * and the primary language subtag and other extlang subtags
>> are ignored.
>
> Should we throw an exeption here? I had an impression that the new
> description actually contradicts to the previous sentense, which asserts
> exception on ill-formed tag.
An exception is thrown when more than three extlang subtags are provided
(ill-formed). The new wording is when an allowed amount of extlang subtags are
provided (not ill-formed). For example,
`new Locale.Builder().setLanguageTag("zh-yue-gan-cmn-czh-CN").build()` // throws
`new Locale.Builder().setLanguageTag("zh-yue-gan-cmn-czh-CN").build()` // ==>
yue_CN
i.e. if one to three extlang subtags occur, discard extras. If more than 3
occur, then it is ill-formed, and the method is already specified to throw on
ill-formed tags.
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PR Review Comment: https://git.openjdk.org/jdk/pull/25309#discussion_r2096619811
