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#include <mbgl/text/language_tag.hpp>
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunknown-pragmas"
#pragma GCC diagnostic ignored "-Wunused-parameter"
#pragma GCC diagnostic ignored "-Wshadow"
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wshorten-64-to-32"
#pragma clang diagnostic ignored "-Wtautological-constant-compare"
#include <boost/spirit/include/qi.hpp>
#include <boost/spirit/include/phoenix_core.hpp>
#include <boost/spirit/include/phoenix_operator.hpp>
#pragma clang diagnostic pop
#pragma GCC diagnostic pop
#include <sstream>
/*
ABNF for BCP 47 from: https://tools.ietf.org/html/bcp47
Language-Tag = langtag ; normal language tags
/ privateuse ; private use tag
/ grandfathered ; grandfathered tags NOT IMPLEMENTED
langtag = language
["-" script]
["-" region]
*("-" variant)
*("-" extension)
["-" privateuse]
language = 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
extlang = 3ALPHA ; selected ISO 639 codes
*2("-" 3ALPHA) ; permanently reserved
script = 4ALPHA ; ISO 15924 code
region = 2ALPHA ; ISO 3166-1 code
/ 3DIGIT ; UN M.49 code
variant = 5*8alphanum ; registered variants
/ (DIGIT 3alphanum)
extension = singleton 1*("-" (2*8alphanum))
; Single alphanumerics
; "x" reserved for private use
singleton = DIGIT ; 0 - 9
/ %x41-57 ; A - W
/ %x59-5A ; Y - Z
/ %x61-77 ; a - w
/ %x79-7A ; y - z
privateuse = "x" 1*("-" (1*8alphanum))
grandfathered = irregular ; non-redundant tags registered
/ regular ; during the RFC 3066 era
irregular = "en-GB-oed" ; irregular tags do not match
/ "i-ami" ; the 'langtag' production and
/ "i-bnn" ; would not otherwise be
/ "i-default" ; considered 'well-formed'
/ "i-enochian" ; These tags are all valid,
/ "i-hak" ; but most are deprecated
/ "i-klingon" ; in favor of more modern
/ "i-lux" ; subtags or subtag
/ "i-mingo" ; combination
/ "i-navajo"
/ "i-pwn"
/ "i-tao"
/ "i-tay"
/ "i-tsu"
/ "sgn-BE-FR"
/ "sgn-BE-NL"
/ "sgn-CH-DE"
regular = "art-lojban" ; these tags match the 'langtag'
/ "cel-gaulish" ; production, but their subtags
/ "no-bok" ; are not extended language
/ "no-nyn" ; or variant subtags: their meaning
/ "zh-guoyu" ; is defined by their registration
/ "zh-hakka" ; and all of these are deprecated
/ "zh-min" ; in favor of a more modern
/ "zh-min-nan" ; subtag or sequence of subtags
/ "zh-xiang"
alphanum = (ALPHA / DIGIT) ; letters and numbers
*/
namespace mbgl {
namespace qi = boost::spirit::qi;
namespace phoenix = boost::phoenix;
namespace ascii = boost::spirit::ascii;
template <typename Iterator>
struct bcp47_parser : qi::grammar<Iterator>
{
bcp47_parser() : bcp47_parser::base_type(start)
{
using qi::lit;
using qi::repeat;
using qi::inf;
using qi::eoi;
using ascii::char_;
using ascii::no_case;
using ascii::digit;
using ascii::alnum;
using ascii::alpha;
using boost::spirit::qi::_1;
start %= no_case[langtag | privateuse | grandfathered];
langtag %= (language) [phoenix::ref(languageTag.language) = _1]
>> -("-" >> (script)[phoenix::ref(languageTag.script) = _1])
>> -("-" >> (region)[phoenix::ref(languageTag.region) = _1])
>> *("-" >> variant)
>> *("-" >> extension)
>> -("-" >> privateuse);
language %= (repeat(2,3)[alpha] >> -("-" >> extlang)) // shortest ISO 639 code
// sometimes followed by extended language subtags
| repeat(4)[alpha] // or reserved for future use
| repeat(5,8)[alpha]; // or registered language subtag
// We add lookaheads for "-"/eoi so that spurious matches on subtags don't prevent backtracking
extlang = repeat(3)[alpha] >> (&lit('-') | eoi) >> repeat(0,2)["-" >> repeat(3)[alpha] >> (&lit('-') | eoi)];
script = repeat(4)[alpha] >> (&lit('-') | eoi);
region = (repeat(2)[alpha] | repeat(3)[digit]) >> (&lit('-') | eoi);
variant = (repeat(5,8)[alnum] | (digit >> repeat(3,inf)[alnum])) >> (&lit('-') | eoi);
extension = singleton >> +("-" >> repeat(2,8)[alnum]) >> (&lit('-') | eoi);
singleton = digit | char_('a','w') | char_('y','z'); // "no-case" handles A-W and Y-Z
privateuse = "x" >> +("-" >> repeat(1,8)[alnum]) >> (&lit('-') | eoi);
grandfathered = regular | irregular;
irregular = lit("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 = lit("art-lojban")
| "cel-gaulish"
| "no-bok"
| "no-nyn"
| "zh-guoyu"
| "zh-hakka"
| "zh-min"
| "zh-min-nan"
| "zh-xiang";
}
qi::rule<Iterator> start;
qi::rule<Iterator> langtag;
qi::rule<Iterator, std::string()> language;
qi::rule<Iterator> extlang;
qi::rule<Iterator, std::string()> script;
qi::rule<Iterator, std::string()> region;
qi::rule<Iterator> variant;
qi::rule<Iterator> extension;
qi::rule<Iterator> singleton;
qi::rule<Iterator> privateuse;
qi::rule<Iterator> grandfathered;
qi::rule<Iterator> irregular;
qi::rule<Iterator> regular;
LanguageTag languageTag;
};
LanguageTag LanguageTag::fromBCP47(const std::string& bcp47Tag) {
typedef std::string::const_iterator iterator_type;
typedef bcp47_parser<iterator_type> bcp47_parser;
bcp47_parser parser;
std::string::const_iterator iter = bcp47Tag.begin();
std::string::const_iterator end = bcp47Tag.end();
bool r = parse(iter, end, parser);
if (r && iter == end) {
return parser.languageTag;
} else {
// Invalid tags are treated as empty/"default"
return LanguageTag();
}
}
LanguageTag::LanguageTag(optional<std::string> language_, optional<std::string> script_, optional<std::string> region_)
: language(std::move(language_))
, script(std::move(script_))
, region(std::move(region_))
{}
std::string LanguageTag::toBCP47() const {
std::stringstream bcp47;
if (!language) {
// BCP 47 requires a language, but we're matching implementations that accept ""
// to mean something like "default"
return bcp47.str();
} else {
bcp47 << *language;
}
if (script) {
bcp47 << "-" << *script;
}
if (region) {
bcp47 << "-" << *region;
}
return bcp47.str();
}
} // end namespace mbgl
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