make-plural

make-plural provides JavaScript functions determining the pluralization categories of the approximately 200 languages included in the Unicode CLDR.
In addition to the more commonly considered cardinal plurals (e.g. one book, two books), it also support ordinal plurals (e.g. 1st book, 2nd book, etc).
It's used internally by the intl-pluralrules polyfill.

The categorization functions are pre-compiled, require no runtime dependencies, and should compress to about 2.5kB.
The ES module exports in particular are designed to work well with tree-shaking, allowing for further size savings.
In order to generate an even smaller file from a subset of all possible language or to otherwise customise the modules, use make-plural-cli or make-plural-compiler.

Installation & Usage

npm install make-plural

 import * as Plurals from 'make-plural/plurals' // or just 'make-plural'
import * as Cardinals from 'make-plural/cardinals'
import * as Examples from 'make-plural/examples'
import * as Ordinals from 'make-plural/ordinals'
import * as Categories from 'make-plural/pluralCategories'
import * as PluralRanges from 'make-plural/ranges'

Each of the endpoints is available with both UMD (.js) and ES (.mjs) packaging.

• Cardinals, Ordinals and Plurals each export a set of functions keyed by locale code,
  returning the pluralization category for the input (either a number or a string representation of a number).
  Plurals functions also accept a second boolean parameter to return
  the ordinal (true) rather than cardinal (false, default) plural category.
  Note that Ordinals includes a slightly smaller subset of locales than Cardinals and Plurals,
  due to a lack of data in the CLDR.
• PluralRanges provides a set of functions similarly keyed by locale code,
  but returning the pliralization category of a numerical range,
  given the corresponding categories of its start and end values as arguments.
• Categories has a similar structure,
  but contains for each language an array of the pluralization categories
  the cardinal and ordinal rules that that language's pluralization function may output.
• Examples provide sample numeric values for each language's categories.

The object keys are named using the corresponding 2-3 character language code.
Due to JavaScript identifier restrictions, there are two exceptions:
Portugese as spoken in Portugal (pt-PT; pt is Brazilian Portuguese) is available as pt_PT, and the now-deprecated in subtag for Indonesian (preferred: id) is available as _in.
The transformation used for these names is available as safe-identifier on npm.

The package file paths and exports are structured in a manner that should allow transparent usage in any module system.
In particular, when importing as an ES6 module, tree shaking should be able drop all but the explicitly used functions from the output, provided that named rather than wildcard imports are used.

 import { en } from 'make-plural'

en(1) // 'one'
en('1.0') // 'other'
en(2) // 'other'
en(2, true) // 'two' (ordinal)

String(en)
// (n, ord) => {
//   const s = String(n).split('.'), v0 = !s[1], t0 = Number(s[0]) == n, n10 = t0 && s[0].slice(-1), n100 = t0 && s[0].slice(-2);
//   if (ord) return n10 == 1 && n100 != 11 ? 'one'
//     : n10 == 2 && n100 != 12 ? 'two'
//     : n10 == 3 && n100 != 13 ? 'few'
//     : 'other';
//   return n == 1 && v0 ? 'one' : 'other';
// }

import { en as ordinalEn } from 'make-plural/ordinals'

ordinalEn(3) // 'few'

import * as Categories from 'make-plural/pluralCategories'
// { _in: { cardinal: [ 'other' ], ordinal: [ 'other' ] },
//   af: { cardinal: [ 'one', 'other' ], ordinal: [ 'other' ] },
//   ak: { cardinal: [ 'one', 'other' ], ordinal: [ 'other' ] },
//   am: { cardinal: [ 'one', 'other' ], ordinal: [ 'other' ] },
//   ar:
//    { cardinal: [ 'zero', 'one', 'two', 'few', 'many', 'other' ],
//      ordinal: [ 'other' ] },
// ...
//   en: {
//       cardinal: [ 'one', 'other' ],
//       ordinal: [ 'one', 'two', 'few', 'other' ]
//     },
// ...
//   zh: { cardinal: [ 'other' ], ordinal: [ 'other' ] },
//   zu: { cardinal: [ 'one', 'other' ], ordinal: [ 'other' ] } }

import { en as rangeEn, ro as rangeRo } from 'make-plural/ranges'

String(rangeEn)
// (start, end) => "other"

String(rangeRo)
// (start, end) => end === "few" ? "few" : end === "one" ? "few" : "other"