Add style/type to ListFormatter public API
Description
C API for ListFormatter doesn't have support for style/type of the formatter.
The unstable API has `style` parameter which can be "standard", "duration", or "duration-short".
I assume that the selection has been based on CLDR categories that we recently updated ( http://unicode.org/cldr/trac/ticket/9361 ).
We now have two types of lists - standard and unit (and we're talking about adding a third for formatting list of numbers)
And we have three styles of lists - long, short and narrow.
It would be great to get the stable API to support those two parameters.
Activity
Thanks for the work! The API surface looks good. I like changing out the strings in the old @internal API for enums.
I cloned your branch and added the following changes:
Added tests
Added C++ version of the API
Changed C to invoke the C++ version
I sent an API proposal and a PR:
https://github.com/unicode-org/icu/pull/894
Other notes:
We typically use SHORT as the default width in APIs, not LONG.
You can use C++ in implementation files. We have a helper class CharString to do string concatenation so you don't have to do all the strcpy stuff. However, this is moot since I rewired the C implementation to invoke the new C++ factory method.
(Not certain whether I have time to send the icu-design mail, in part for lack of time, but also because I think my existing subscription probably is no longer accessible to me because MIT’s mail system abruptly stopped supporting +foo notation and so I’ve probably lost account access. I really ought resubscribe, but…time.)
I did the local hacking to churn out a patch for the API as proposed above. (Roughly – I changed “style” mentions to “width” because it seemed maybe a better name, and moreover ListFormatter::createInstance called its different/distinct parameter style so it seemed unwise to use the same name.) I’ve tried to test it, but for some reason my locally-built ICU tip throws an exception when trying to call umtx_lock nested beneath the new API entrypoint, and that could easily be me screwing up how ICU was built, so I don’t know if it actually works. But it’s gotta be at least a good start.
The style method was added to C++ in
https://github.com/unicode-org/icu/commit/ecd7ea193b6c8740c06ebaa59a771afee993029a
If the behavior is stable, I would support promoting this method from internal to draft. An argument could even be made to promote this from internal to stable "de facto".
A C API can also be added.
Comment from Jeff Walden via email:
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We do sometimes use unstable ICU C++ API, if we must and the need is sufficiently important and the C++ API looks unofficially pretty stable. It appears
is the only extra unstable API needed. (We depend on unstable icu::Locale::Locale(const char*) for other reasons already.)
U_HIDE_INTERNAL_API suggests ICU developers would change this without even thinking about it. I think it doesn't affect whether a system ICU would provide it (e.g. Fedora has it). We technically could take the dependency, but I think U_HIDE_INTERNAL_API concerns push this past the point where I want to take it.
That said, a straightforward
patterned off the existing
where type/style are conjunction/disjunction/unit and narrow/short/long enums looks easy. I'll look into writing such a patch and posting it and mailing icu-design tomorrow. We take local patches that upstream has landed but not shipped yet more easily than we'll take dodgy C++ unstable API use. Not quite a workaround, but I guess this has to happen sooner or later, might as well be sooner.