On Thu, 2023-05-18 at 13:58 -0400, Jonathan S. Katz wrote: > From my read of them, as an app developer I'd be very unlikely to > use > this. Maybe there is something with building out some collation rules > vis-a-vis an extension, but I have trouble imagining the use-case. I > may > also not be the target audience for this feature.
That's a problem for the ICU rules feature. I understand some features may be for domain experts only, but we at least need to call that out so that ordinary developers don't get confused. And we should hear from some of those domain experts that they actually want it and it solves a real problem. For the features that can be described with collation settings/attributes right in the locale name, the use cases are more plausible and we've supported them since v10, so it's good to document them as best we can. It's hard to expose only the particular ICU collation settings we understand best (e.g. the "ks" setting that allows case insensitive collation), so it's inevitable that there will be some settings that are more obscure and harder to document. But in the case of ICU rules, they are newly-supported in 16, so there should be a clear reason we're adding them. Otherwise we're just setting up users for confusion or problems, and creating backwards- compatibility headaches for ourselves (and the last thing we want is to fret over backwards compatibility for a feature with no users). Beyond that, there seems to be some danger: if the syntax for rules is not perfectly compatible between ICU versions, the user might run into big problems. Regards, Jeff Davis