howdy/i18n

Translations for Howdy apps.

A Translator is a locale with everything needed to write in it: the locales to fall back to, plural rules, and the CLDR data that howdy/i18n/format writes numbers, dates and lists with.

let t = i18n.new("de-CH")
messages.cart_items(t, count: 3)   // "3 Artikel"
format.date(t, today, format.Long)  // "19. Oktober 2026"

Messages live in JSON catalogues, one per locale, written in ICU MessageFormat, and gleam run -m howdy/i18n/cli gen turns them into a Gleam module with a function for each message. See howdy/i18n/cli.

Pass the tag howdy/locale chose for the request: i18n.new( locale.to_string(locale.detect(ctx, locales))). This package does not depend on Howdy itself, so it also works in code compiled to JavaScript.

Types

Translator

opaque </>

pub opaque type Translator

Values

canonical

</>

pub fn canonical(tag: String) -> String

A tag in canonical case, with _ read as -: zh-Hant-TW. Chinese for Taiwan, Hong Kong and Macau gains its traditional script.

cldr_version

</>

pub fn cldr_version() -> String

The version of CLDR the data and plural rules come from.

data_locale

</>

pub fn data_locale(translator: Translator) -> String

The locale whose formatting data the translator uses.

data_locales

</>

pub fn data_locales() -> List(String)

The locales with formatting data of their own.

fallbacks

</>

pub fn fallbacks(translator: Translator) -> List(String)

The locale and those it falls back to, most specific first: es-AR, es-419, es.

language_name

</>

pub fn language_name(locale: String) -> Result(String, Nil)

The name of a locale in its own language, such as Deutsch for de, for a language switcher. Error for a locale without data.

locale

</>

pub fn locale(translator: Translator) -> String

The tag, in canonical case: pt-BR.

new

</>

pub fn new(locale: String) -> Translator

A translator for a BCP 47 tag such as pt-BR. Any tag works: one without data of its own uses the nearest locale that has some, and English in the end.

pick

</>

pub fn pick(
  translator: Translator,
  available: List(String),
) -> String

Which of available catalogue locales to use: the first the translator falls back to, or one of the same language, or "" when there is none. Generated catalogues call this to choose their words.