languageTagPrefixes
languageTagPrefixes(
tag):string[]
Defined in: packages/format-language-tag/src/match-language.ts:45
A language tag and each of its progressive truncations, longest first.
en-Latn-US-u-co-phonebk yields en-Latn-US-u-co, then en-Latn-US —
skipping en-Latn-US-u, since RFC 4647 §3.4 discards a truncation that ends
in a singleton subtag — then en-Latn and en.
Accepts any hyphen-separated subtag sequence, not only a well-formed tag,
because lookupLanguageTag truncates ranges with it.
Runs in O(n²) characters for n subtags, which is bounded by the grammar.
Parameters
Section titled “Parameters”string
Returns
Section titled “Returns”string[]