@pico-intl-dev/messageformat

Optional full ICU MessageFormat resolver for pico-intl.

Core stays dependency-free and keeps its ICU-lite syntax. Use this package when your product needs advanced ICU semantics such as exact plural selectors, offsets, nested plural/select messages, selectordinal, and locale-specific plural categories for languages such as Arabic, Russian, and Polish.

npm install @pico-intl-dev/core @pico-intl-dev/messageformat

import { createI18n } from '@pico-intl-dev/core';
import { createMessageFormatResolver } from '@pico-intl-dev/messageformat';

const i18n = createI18n({
  base: 'en',
  locale: 'pl',
  messages: {
    files: '{count, plural, one {# plik} few {# pliki} many {# plikow} other {# pliku}}',
  },
  resolver: createMessageFormatResolver(),
});

i18n.t('files', { count: 22 });

Supported by the underlying ICU MessageFormat engine:

• cardinal plural categories: zero, one, two, few, many, other
• exact selectors such as =0
• plural offset
• select for gender, role, status, and similar variants
• selectordinal
• nested plural/select trees
• number/date/time formatting supported by ICU MessageFormat
• rich text/tag formatting through formatToParts

The resolver caches compiled messages by locale and message string. The default cache limit is 500 compiled messages.

Rich text stays outside pico-intl core. Use the resolver's formatToParts helper when a framework adapter needs to turn ICU tag output into UI nodes:

const resolver = createMessageFormatResolver();

const parts = resolver.formatToParts({
  locale: 'en',
  message: 'Read <link>{name}</link>',
  params: {
    name: 'docs',
    link: (chunks) => `<a>${chunks.join('')}</a>`,
  },
});