Add style ordinal/cardinal to NumberFormat (RBNF)

[romulocintra]

Support formatting ordinals & cardinals

Style Ordinal

console.log(new Intl.NumberFormat('en', { style: 'ordinal' }).format(2));
// 2nd

console.log(new Intl.NumberFormat('pt', { style: 'ordinal' }).format(2));
// 2.º or 2.ª (M/F)

Style Cardinal

console.log(new Intl.NumberFormat('en', { style: 'cardinal' }).format(2));
// second

console.log(new Intl.NumberFormat('pt', { style: 'cardinal' }).format(2));
// segundo or segunda (M/F)

[sffc]

Previous issue: #95. Let's keep this issue focused on Spellout and Ordinal specifically. However, the underlying code for these two styles is the same as for the algorithmic numbering systems (native, traditio, finance) listed in #95.

[sffc]

See some good discussion on tc39/proposal-intl-numberformat-v3#22. CC @Bx1

[karlhorky]

Oh this looks great! 😍

new Intl.NumberFormat('en', { style: 'ordinal' }).format(2) // '2nd'

Having a built-in web platform way to create the localized strings "1st", "2nd", "3rd" would be amazing.

Currently, for English ordinals, using either 1) self-written code with Intl.PluralRules() or 2) the ordinal npm package:

// Option 1: self-written w. Intl.PluralRules() https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/PluralRules/PluralRules
const pr = new Intl.PluralRules("en-US", { type: "ordinal" });

const suffixes = new Map([
  ["one", "st"],
  ["two", "nd"],
  ["few", "rd"],
  ["other", "th"],
]);
const formatOrdinals = (n) => {
  const rule = pr.select(n);
  const suffix = suffixes.get(rule);
  return `${n}${suffix}`;
};

formatOrdinals(0); // '0th'
formatOrdinals(1); // '1st'
formatOrdinals(2); // '2nd'
formatOrdinals(3); // '3rd'

// Option 2: ordinal package https://www.npmjs.com/package/ordinal
import ordinal from 'ordinal';

ordinal(1) // '1st'
ordinal(2) // '2nd'
ordinal(3) // '3rd'

I saw that it was accepted by the MessageFormat Working Group in Feb 2024 (but unsure how exactly that interacts with ECMA 402 / any changes to Intl.NumberFormat() 🤔)

I understand that there is still ICU4X / 402 work to be done.

@sffc Maybe for visibility a new issue could be opened in https://github.com/tc39/proposal-intl-numberformat-v3 ? The last one is closed. Or does this need a new Intl.NumberFormat v4 proposal repo?

[eemeli]

I saw that it was accepted by the MessageFormat Working Group in Feb 2024 (but unsure how exactly that interacts with ECMA 402 / any changes to Intl.NumberFormat() 🤔)

The MF2 :number option that we've ended up with is select, which accepts the values plural (default), ordinal, and exact.

For style, the only current supported values are decimal (default) and percent.

In other words, supporting MF2 does not require adding ordinal number formatting support to Intl.NumberFormat.

[sffc]

TG2 discussion: https://github.com/tc39/ecma402/blob/main/meetings/notes-2024-10-24.md#rbnf

Main conclusion: we are likely supportive of adding the decimal ordinal format (1st 2nd 3rd), as well as the small handful of algorithmic numbering systems. There were concerns about adding the spellout style due to the data size.

Happy for someone to champion this.