103 lines
3.4 KiB
JavaScript
103 lines
3.4 KiB
JavaScript
import assertString from './util/assertString';
|
|
/*
|
|
= 3ALPHA ; selected ISO 639 codes
|
|
*2("-" 3ALPHA) ; permanently reserved
|
|
*/
|
|
|
|
var extlang = '([A-Za-z]{3}(-[A-Za-z]{3}){0,2})';
|
|
/*
|
|
= 2*3ALPHA ; shortest ISO 639 code
|
|
["-" extlang] ; sometimes followed by
|
|
; extended language subtags
|
|
/ 4ALPHA ; or reserved for future use
|
|
/ 5*8ALPHA ; or registered language subtag
|
|
*/
|
|
|
|
var language = "(([a-zA-Z]{2,3}(-".concat(extlang, ")?)|([a-zA-Z]{5,8}))");
|
|
/*
|
|
= 4ALPHA ; ISO 15924 code
|
|
*/
|
|
|
|
var script = '([A-Za-z]{4})';
|
|
/*
|
|
= 2ALPHA ; ISO 3166-1 code
|
|
/ 3DIGIT ; UN M.49 code
|
|
*/
|
|
|
|
var region = '([A-Za-z]{2}|\\d{3})';
|
|
/*
|
|
= 5*8alphanum ; registered variants
|
|
/ (DIGIT 3alphanum)
|
|
*/
|
|
|
|
var variant = '([A-Za-z0-9]{5,8}|(\\d[A-Z-a-z0-9]{3}))';
|
|
/*
|
|
= DIGIT ; 0 - 9
|
|
/ %x41-57 ; A - W
|
|
/ %x59-5A ; Y - Z
|
|
/ %x61-77 ; a - w
|
|
/ %x79-7A ; y - z
|
|
*/
|
|
|
|
var singleton = '(\\d|[A-W]|[Y-Z]|[a-w]|[y-z])';
|
|
/*
|
|
= singleton 1*("-" (2*8alphanum))
|
|
; Single alphanumerics
|
|
; "x" reserved for private use
|
|
*/
|
|
|
|
var extension = "(".concat(singleton, "(-[A-Za-z0-9]{2,8})+)");
|
|
/*
|
|
= "x" 1*("-" (1*8alphanum))
|
|
*/
|
|
|
|
var privateuse = '(x(-[A-Za-z0-9]{1,8})+)'; // irregular tags do not match the 'langtag' production and would not
|
|
// otherwise be considered 'well-formed'. These tags are all valid, but
|
|
// most are deprecated in favor of more modern subtags or subtag combination
|
|
|
|
var irregular = '((en-GB-oed)|(i-ami)|(i-bnn)|(i-default)|(i-enochian)|' + '(i-hak)|(i-klingon)|(i-lux)|(i-mingo)|(i-navajo)|(i-pwn)|(i-tao)|' + '(i-tay)|(i-tsu)|(sgn-BE-FR)|(sgn-BE-NL)|(sgn-CH-DE))'; // regular tags match the 'langtag' production, but their subtags are not
|
|
// extended language or variant subtags: their meaning is defined by
|
|
// their registration and all of these are deprecated in favor of a more
|
|
// modern subtag or sequence of subtags
|
|
|
|
var regular = '((art-lojban)|(cel-gaulish)|(no-bok)|(no-nyn)|(zh-guoyu)|' + '(zh-hakka)|(zh-min)|(zh-min-nan)|(zh-xiang))';
|
|
/*
|
|
= irregular ; non-redundant tags registered
|
|
/ regular ; during the RFC 3066 era
|
|
|
|
*/
|
|
|
|
var grandfathered = "(".concat(irregular, "|").concat(regular, ")");
|
|
/*
|
|
RFC 5646 defines delimitation of subtags via a hyphen:
|
|
|
|
"Subtag" refers to a specific section of a tag, delimited by a
|
|
hyphen, such as the subtags 'zh', 'Hant', and 'CN' in the tag "zh-
|
|
Hant-CN". Examples of subtags in this document are enclosed in
|
|
single quotes ('Hant')
|
|
|
|
However, we need to add "_" to maintain the existing behaviour.
|
|
*/
|
|
|
|
var delimiter = '(-|_)';
|
|
/*
|
|
= language
|
|
["-" script]
|
|
["-" region]
|
|
*("-" variant)
|
|
*("-" extension)
|
|
["-" privateuse]
|
|
*/
|
|
|
|
var langtag = "".concat(language, "(").concat(delimiter).concat(script, ")?(").concat(delimiter).concat(region, ")?(").concat(delimiter).concat(variant, ")*(").concat(delimiter).concat(extension, ")*(").concat(delimiter).concat(privateuse, ")?");
|
|
/*
|
|
Regex implementation based on BCP RFC 5646
|
|
Tags for Identifying Languages
|
|
https://www.rfc-editor.org/rfc/rfc5646.html
|
|
*/
|
|
|
|
var languageTagRegex = new RegExp("(^".concat(privateuse, "$)|(^").concat(grandfathered, "$)|(^").concat(langtag, "$)"));
|
|
export default function isLocale(str) {
|
|
assertString(str);
|
|
return languageTagRegex.test(str);
|
|
} |