type.temporal_locales_required: Formatting needs declared locales

Formatting needs declared locales.

Area 10, Configuration and time; not declinable; the next step is usually the agent's.

A project that formats text for people declares the locales it supports:

example

use shop/types { OrderedAt, PlacedText }/// The placing, in the customer's language.action show_placed(ordered_at: OrderedAt, reader_locale: Locale) -> PlacedText {    return PlacedText {        placed: text.format(            ordered_at,            zone: Zone.utc,            locale: reader_locale,            format: TimeFormat.date_long        )    }}

text

error: `text.format` needs the application's locales --> domains/shop/actions/show_placed.jadpo:6:17  |6 |         placed: text.format(  |                 ^^^^^^^^^^^ no locales declared  reason: Text for a person is written in one of the locales the application supports. None is declared, so there is nothing to check `locale:` against, and nothing for a request with no usable `Accept-Language` to fall back to.  next: Declare them in `app.jadpo`, for instance `locales { default: Locale.en_gb supported: [Locale.en_gb] }` (agent)  rule: type.temporal_locales_required  help: https://jadpo.dev/docs/errors/type.temporal_locales_requiredcheck failed: 1 error, 4 files

The same rule covers choosing a locale from a request, since there is nothing to choose among and nothing to fall back to:

example

use shop/types { BrowserLanguages }/// The language the customer's browser asks for.action locale_for_reader(languages_header: BrowserLanguages?) -> Locale {    return locale.from_accept_language(languages_header)}

text

error: `locale.from_accept_language` needs the application's locales --> domains/shop/actions/locale_for_reader.jadpo:5:12  |5 |     return locale.from_accept_language(languages_header)  |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^ no locales declared  reason: `locale.from_accept_language` chooses among the locales the application supports and falls back to its `default:`. None is declared, so there is nothing to choose among and nothing to fall back to.  next: Declare them in `app.jadpo`, for instance `locales { default: Locale.en_gb supported: [Locale.en_gb] }` (agent)  rule: type.temporal_locales_required  help: https://jadpo.dev/docs/errors/type.temporal_locales_requiredcheck failed: 1 error, 3 files

And sorting by a locale's alphabet, since a deployable carries collation for the declared locales only:

example

use shop/types { LoafName }/// The loaves in the order the shopper's alphabet puts them.action in_name_order(loaves: List<LoafName>, shopper: Locale) -> List<LoafName> {    return list.sort_by(loaves, loaf -> loaf, locale: shopper)}

text

error: `list.sort_by` needs the application's locales --> domains/shop/actions/in_name_order.jadpo:5:12  |5 |     return list.sort_by(loaves, loaf -> loaf, locale: shopper)  |            ^^^^^^^^^^^^ no locales declared  reason: `locale:` orders text by the alphabet of one of the locales the application supports, and a deployable carries only those locales' collation. None is declared, so there is no alphabet to sort by.  next: Declare them in `app.jadpo`, for instance `locales { default: Locale.en_gb supported: [Locale.en_gb] }` (agent)  rule: type.temporal_locales_required  help: https://jadpo.dev/docs/errors/type.temporal_locales_requiredcheck failed: 1 error, 3 files