The reason why I want to modify their behavior is that a large number of programs have misused this method. By modifying the behavior, we can fix them without modifying their source code.
However, it may be a better choice to mark it as deprecated. After deprecating them, we can provide new API methods that use Locale.ROOT by default as a substitute. Kotlin is using methods called lowercase() and uppercase() for this purpose, which I think can be used for reference. On Thu, Jan 26, 2023 at 9:36 PM Remi Forax <fo...@univ-mlv.fr> wrote: > > > ------------------------------ > > *From: *"Glavo" <zjx001...@gmail.com> > *To: *"core-libs-dev" <core-libs-dev@openjdk.org> > *Sent: *Thursday, January 26, 2023 1:35:06 PM > *Subject: *[Proposal] Make toLowerCase and toUpperCase based on > Locale.ROOT by default > > At present, the no-parameter toLowerCase and toUpperCase methods of String > are based on the default locale. > > I checked all the uses of this method in OpenJDK, and found that most of > the use cases are suspicious, and even there are some hidden bugs. > For example, I just found that jdk.incubator.vector.LaneType will trigger > assertion failure on Turkish locale, and opened a PR for this problem: > > https://github.com/openjdk/panama-vector/pull/210 > > In addition to such obvious problems, some use cases behave suspiciously > after calling Locale.setDefault. > I am investigating these problems and preparing to open a PR to solve > these hidden bugs. > > In all the third-party libraries I have used, I have never seen the > correct use of these two methods. > Although the behavior of modifying API methods is destructive, I think it > is worthwhile to consider whether to modify its behavior for such a > suspicious method. > If users need locale-sensitive case conversion, it may be better to > explicitly use Locale.getDefault(). > Using Locale.ROOT as the default value also helps to keep the behavior of > these two methods consistent with equalsIgnoreCase, > Character.toLowerCase/toUpperCase and other methods. > > This is my rough idea. I hope to get your suggestions. > > > yes, it's a very very common bug, IntelliJ already warns when > toLowerCase()/toUpperCase() is used without a Locale. > I think the logical nest step is more to deprecate > toLowerCase()/toUpperCase() than to change their implementation. > > regards, > Rémi > >
