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