1673545 - Support NumberFormat rev. 2 in Fluent

Status: NEW

(Core :: Internationalization: Localization, defect)

Description

[Francesco Lodolo [:flod]]

NUMBER(100, signDisplay: "always")
NUMBER(-99, signDisplay: "never")

In Firefox this will display 100 and -99, while on Fluent's playground it will display correctly +100 and 99.

Also getting correctly +100 in Console with

new Intl.NumberFormat("en-US", {    
    signDisplay: "always"
}).format([100]);

Comment 1

[Zibi Braniecki [:zbraniecki][:gandalf]]

This is just a new addition to ECMA-402 that has to be propagated to https://searchfox.org/mozilla-central/source/intl/l10n/rust/fluent-ffi/src/ffi.rs#49 and then used in https://searchfox.org/mozilla-central/source/intl/l10n/FluentBundle.cpp#210

Comment 2

[Zibi Braniecki [:zbraniecki][:gandalf]]

We should extend this bug to cover other features supported by Unified Number Format (NumberFormat rev. 2) proposal https://github.com/tc39/proposal-unified-intl-numberformat

The functionality is there, but in some cases the operations between C++ and options bag are not trivial, and we should closely follow what SpiderMonkey is doing here https://searchfox.org/mozilla-central/source/js/src/builtin/intl/NumberFormat.cpp#496

Comment 3

[Zibi Braniecki [:zbraniecki][:gandalf]]

With bug 1695937 fixed, Gecko can now handle NumberFormat rev. 2!

What's left is to add support for it into fluent-rs. NumberFormat is this weird outlier for now, since it is defined in fluent-rs itself because we do need to format numbers (compared to DateTime which is a CustomType and doesn't exist in fluent-rs itself), even in a quasi way.

Eventually, I expect fluent-bundle to just depend on icu_number which should handle it well, but for now, we will have to:

1. Extend https://github.com/projectfluent/fluent-rs/blob/master/fluent-bundle/src/types/number.rs#L60 to pass through all new options from https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/NumberFormat/NumberFormat
2. Extend https://searchfox.org/mozilla-central/source/intl/l10n/rust/fluent-ffi/src/ffi.rs#49 to match it
3. Extend https://searchfox.org/mozilla-central/source/intl/l10n/FluentBundle.cpp#212 to match it

That should do it.

In theory we could try to make mozilla::intl::NumberFormatOptions accessible from Rust so that we could remove NumberFormatOptionsRaw and just construct the m::i::NumberFormatOptions from fluent::types::NumberFormatOptions, but I'm not sure if that type will work well as exposed to Rust.

:dminor - what do you think?

Comment 4

[Dan Minor [:dminor]]

I think everything in mozilla::intl::NumberFormatOptions has a natural rust representation, but I think we'd have to write manual wrappers to get it working. I spent a little bit of time with bindgen this morning, and it was not generating anything sensible for mozilla::Maybe. I don't think it's worth investing in writing manual wrappers when we eventually plan to just call into icu_number directly, so your steps 1 - 3 make good sense to me.

Comment 5

[BugBot [:suhaib / :marco/ :calixte]]

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