wiki.techinc.nl/includes/language/LanguageCode.php
Amir Sarabadani 92abd6cd1b Language: Mark constructor of LanguageCode unstable for now
Since the branch cut is now, let's make this unstable for now and then
change it once we are confident it'll be stable.

Bug: T376565
Change-Id: Id7dd735abc5a97a0dfbd50484a8ae989b6c1738f
2024-10-22 01:39:37 +02:00

381 lines
14 KiB
PHP

<?php
/**
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
* http://www.gnu.org/copyleft/gpl.html
*
* @file
*/
namespace MediaWiki\Language;
use Wikimedia\Bcp47Code\Bcp47Code;
use Wikimedia\Bcp47Code\Bcp47CodeValue;
/**
* Methods for dealing with language codes.
*
* @since 1.29
* @ingroup Language
*/
class LanguageCode {
private string $code;
/**
* @param string $code
* @unstable
* @since 1.43
*/
public function __construct( string $code ) {
$this->code = $code;
}
/**
* @return string
* @since 1.43
*/
public function toString(): string {
return $this->code;
}
/**
* Mapping of deprecated language codes that were used in previous
* versions of MediaWiki to up-to-date, current language codes.
* These may or may not be valid BCP 47 codes; they are included here
* because MediaWiki renamed these particular codes at some point.
*
* @var array Mapping from deprecated MediaWiki-internal language code
* to replacement MediaWiki-internal language code.
*
* @see https://meta.wikimedia.org/wiki/Special_language_codes
*/
private const DEPRECATED_LANGUAGE_CODE_MAPPING = [
// Note that als is actually a valid ISO 639 code (Tosk Albanian), but it
// was previously used in MediaWiki for Alsatian, which comes under gsw
'als' => 'gsw', // T25215
'bat-smg' => 'sgs', // T27522
'be-x-old' => 'be-tarask', // T11823
'fiu-vro' => 'vro', // T31186
'roa-rup' => 'rup', // T17988
'zh-classical' => 'lzh', // T30443
'zh-min-nan' => 'nan', // T30442
'zh-yue' => 'yue', // T30441
];
/**
* Mapping of non-standard language codes used in MediaWiki to
* standardized BCP 47 codes. These are not deprecated (yet?):
* IANA may eventually recognize the subtag, in which case the `-x-`
* infix could be removed, or else we could rename the code in
* MediaWiki, in which case they'd move up to the above mapping
* of deprecated codes.
*
* As a rule, we preserve all distinctions made by MediaWiki
* internally. For example, `de-formal` becomes `de-x-formal`
* instead of just `de` because MediaWiki distinguishes `de-formal`
* from `de` (for example, for interface translations). Similarly,
* BCP 47 indicates that `kk-Cyrl` SHOULD not be used because it
* "typically does not add information", but in our case MediaWiki
* LanguageConverter distinguishes `kk` (render content in a mix of
* Kurdish variants) from `kk-Cyrl` (convert content to be uniformly
* Cyrillic). As the BCP 47 requirement is a SHOULD not a MUST,
* `kk-Cyrl` is a valid code, although some validators may emit
* a warning note.
*
* @var array Mapping from nonstandard MediaWiki-internal codes to
* BCP 47 codes
*
* @see https://meta.wikimedia.org/wiki/Special_language_codes
* @see https://phabricator.wikimedia.org/T125073
*/
private const NON_STANDARD_LANGUAGE_CODE_MAPPING = [
// All codes returned by LanguageNameUtils::getLanguageNames() validated
// against IANA registry at
// https://www.iana.org/assignments/language-subtag-registry/language-subtag-registry
// with help of validator at
// http://schneegans.de/lv/
'cbk-zam' => 'cbk', // T124657
'de-formal' => 'de-x-formal',
'eml' => 'egl', // T36217
'en-rtl' => 'en-x-rtl',
'es-formal' => 'es-x-formal',
'hu-formal' => 'hu-x-formal',
'map-bms' => 'jv-x-bms', // [[en:Banyumasan_dialect]] T125073
'mo' => 'ro-Cyrl-MD', // T125073
'nrm' => 'nrf', // [[en:Norman_language]] T25216
'nl-informal' => 'nl-x-informal',
'roa-tara' => 'nap-x-tara', // [[en:Tarantino_dialect]]
'simple' => 'en-simple',
'sr-ec' => 'sr-Cyrl', // T117845
'sr-el' => 'sr-Latn', // T117845
// Although these next codes aren't *wrong* per se, including
// both the script and the country code helps compatibility with
// other BCP 47 users. Note that MW also uses
// `kk-Arab`/`kk-Cyrl`/`kk-Latn`, `zh-Hans`/`zh-Hant`,
// without a country code, and those should be left alone.
// `kk` has the Suppress-Script: Cyrl field, so `kk-KZ` won't be mapped
// to `kk-Cyrl-KZ`.
// (See getVariantsFallbacks() in KkConverter.php for Arab/Cyrl/Latn id.)
// (See getVariantsFallbacks() in ZhConverter.php for Hans/Hant id.)
'crh-ro' => 'crh-Latn-RO',
'kk-cn' => 'kk-Arab-CN',
'kk-tr' => 'kk-Latn-TR',
'zh-cn' => 'zh-Hans-CN',
'zh-sg' => 'zh-Hans-SG',
'zh-my' => 'zh-Hans-MY',
'zh-tw' => 'zh-Hant-TW',
'zh-hk' => 'zh-Hant-HK',
'zh-mo' => 'zh-Hant-MO',
];
/**
* Returns a mapping of deprecated language codes that were used in previous
* versions of MediaWiki to up-to-date, current language codes.
*
* This array is merged into $wgDummyLanguageCodes in
* SetupDynamicConfig.php, along with the fake language codes
* 'qqq' and 'qqx', which are used internally by MediaWiki's
* localisation system.
*
* @return string[]
*
* @since 1.29
*/
public static function getDeprecatedCodeMapping() {
return self::DEPRECATED_LANGUAGE_CODE_MAPPING;
}
/**
* Returns a mapping of non-standard language codes used by
* (current and previous version of) MediaWiki, mapped to standard
* BCP 47 names.
*
* This array is exported to JavaScript to ensure
* mediawiki.language.bcp47 stays in sync with LanguageCode::bcp47().
*
* @return string[]
*
* @since 1.32
*/
public static function getNonstandardLanguageCodeMapping() {
static $result = [];
if ( $result ) {
return $result;
}
foreach ( self::DEPRECATED_LANGUAGE_CODE_MAPPING as $code => $ignore ) {
$result[$code] = self::bcp47( $code );
}
foreach ( self::NON_STANDARD_LANGUAGE_CODE_MAPPING as $code => $ignore ) {
$result[$code] = self::bcp47( $code );
}
return $result;
}
/**
* Replace deprecated language codes that were used in previous
* versions of MediaWiki to up-to-date, current language codes.
* Other values will be returned unchanged.
*
* @param string $code Old language code
* @return string New language code
*
* @since 1.30
*/
public static function replaceDeprecatedCodes( $code ) {
return self::DEPRECATED_LANGUAGE_CODE_MAPPING[$code] ?? $code;
}
/**
* Get the normalised IANA language tag
* See unit test for examples.
* See mediawiki.language.bcp47 for the JavaScript implementation.
*
* @param string $code The language code.
* @return string A language code complying with BCP 47 standards.
*
* @since 1.31
*/
public static function bcp47( $code ) {
$code = self::replaceDeprecatedCodes( strtolower( $code ) );
if ( isset( self::NON_STANDARD_LANGUAGE_CODE_MAPPING[$code] ) ) {
$code = self::NON_STANDARD_LANGUAGE_CODE_MAPPING[$code];
}
$codeSegment = explode( '-', $code );
$codeBCP = [];
foreach ( $codeSegment as $segNo => $seg ) {
// when the previous segment is x, it is a private segment and should be lc
if ( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
$codeBCP[$segNo] = strtolower( $seg );
// ISO 3166 country code
} elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
$codeBCP[$segNo] = strtoupper( $seg );
// ISO 15924 script code
} elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
$codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
// Use lowercase for other cases
} else {
$codeBCP[$segNo] = strtolower( $seg );
}
}
return implode( '-', $codeBCP );
}
/**
* Convert standardized BCP 47 codes to the internal names used
* by MediaWiki and returned by Language::getCode(). This function
* should be the inverse of LanguageCode::bcp47(). Note that BCP 47
* explicitly states that language codes are case-insensitive.
*
* Since LanguageFactory::getLanguage() is pretty generous about
* accepting aliases (as long as they are lowercased), this function
* should be equivalent to:
* LanguageFactory::getLanguage(strtolower($code))->getCode()
* but (a) better describes the caller's intention, and (b) should
* be much more efficient in practice.
*
* @param string|Bcp47Code $code The standard BCP-47 language code
* @return string A MediaWiki-internal code, as returned, for example, by
* Language::getCode()
* @since 1.40
*/
public static function bcp47ToInternal( $code ): string {
if ( $code instanceof Language ) {
return $code->getCode();
}
if ( $code instanceof Bcp47Code ) {
$code = $code->toBcp47Code();
}
static $invertedLookup = [];
if ( !$invertedLookup ) {
// There should never be two different entries in
// NON_STANDARD_LANGUAGE_CODE_MAPPING that map *different*
// internal codes to the same external BCP-47 code. That is,
// BCP-47 should preserve all the information from the internal
// code (discussed further above)[*]. But note the converse isn't
// true: multiple BCP-47 codes can alias to the same internal code:
// BCP-47 internal
// zh-Hans-CN => zh-cn (in NON_STANDARD_LANGUAGE_CODE_MAPPING)
// zh-Hans => zh-hans (not in " )
// zh-CN => zh-cn (not in " )
//
// [*] eml/egl are the "exception that proves the rule": `egl` *is*
// (prematurely?) defined as an internal code, but only
// eml.wikipedia.org exists, and it defines its language as `eml`;
// for internal purposes `egl` should map back into `eml` until
// `eml` is deprecated (aka an `eml => egl` entry is added to
// DEPRECATED_LANGUAGE_CODE_MAPPING): T36217.
foreach ( self::NON_STANDARD_LANGUAGE_CODE_MAPPING as $internal => $bcp47 ) {
$invertedLookup[strtolower( $bcp47 )] = $internal;
}
// We deliberately do *not* use DEPRECATED_LANGUAGE_CODE_MAPPING
// here: deprecated codes are no longer valid mediawiki internal
// codes, and we should never return them.
}
// Internal codes are all lowercase. This also achieves
// case-insensitivity in the lookup.
$code = strtolower( $code );
return $invertedLookup[$code] ?? $code;
}
/**
* We want to eventually require valid BCP-47 codes on HTTP and HTML
* APIs (where the standards require it). This will "prefer" to
* interpret the given $code as BCP-47, but if a mediawiki internal
* code is provided, it will map it to the proper BCP-47 code. We
* don't emit a logged warning on this path yet, but we intend to
* in the future.
*
* @param string $code A "language code" provided from an HTTP or HTML
* API, presumed to be BCP-47
* @return Bcp47Code An "actual" BCP-47 code
* @internal
*/
public static function normalizeNonstandardCodeAndWarn( string $code ): Bcp47Code {
$compatMap = self::getNonstandardLanguageCodeMapping();
if ( isset( $compatMap[strtolower( $code )] ) ) {
// Backward compatibility, since clients may have been
// sending us non-standards-compliant
// "mediawiki internal language codes"; eventually we'll
// emit a logged warning here.
$code = $compatMap[strtolower( $code )];
}
return new Bcp47CodeValue( $code );
}
/**
* Returns true if a language code string is a well-formed language tag
* according to RFC 5646.
* This function only checks well-formedness; it doesn't check that
* language, script or variant codes actually exist in the repositories.
*
* Based on regexes by Mark Davis of the Unicode Consortium:
* https://github.com/unicode-org/icu/blob/37e295627156bc334e1f1e88807025fac984da0e/icu4j/main/tests/translit/src/com/ibm/icu/dev/test/translit/langtagRegex.txt
*
* @param string $code
* @param bool $lenient Whether to allow '_' as separator. The default is only '-'.
*
* @return bool
* @since 1.39
*/
public static function isWellFormedLanguageTag( string $code, bool $lenient = false ): bool {
$alpha = '[a-z]';
$digit = '[0-9]';
$alphanum = '[a-z0-9]';
$x = 'x'; # private use singleton
$singleton = '[a-wy-z]'; # other singleton
$s = $lenient ? '[-_]' : '-';
$language = "$alpha{2,8}|$alpha{2,3}$s$alpha{3}";
$script = "$alpha{4}"; # ISO 15924
$region = "(?:$alpha{2}|$digit{3})"; # ISO 3166-1 alpha-2 or UN M.49
$variant = "(?:$alphanum{5,8}|$digit$alphanum{3})";
$extension = "$singleton(?:$s$alphanum{2,8})+";
$privateUse = "$x(?:$s$alphanum{1,8})+";
# Define certain legacy language tags (marked as “Type: grandfathered” in BCP 47),
# since otherwise the regex is pretty useless.
# Since these are limited, this is safe even later changes to the registry --
# the only oddity is that it might change the type of the tag, and thus
# the results from the capturing groups.
# https://www.iana.org/assignments/language-subtag-registry
$legacy = "en{$s}gb{$s}oed"
. "|i{$s}(?:ami|bnn|default|enochian|hak|klingon|lux|mingo|navajo|pwn|tao|tay|tsu)"
. "|no{$s}(?:bok|nyn)"
. "|sgn{$s}(?:be{$s}(?:fr|nl)|ch{$s}de)"
. "|zh{$s}min{$s}nan";
$variantList = "$variant(?:$s$variant)*";
$extensionList = "$extension(?:$s$extension)*";
$langtag = "(?:($language)"
. "(?:$s$script)?"
. "(?:$s$region)?"
. "(?:$s$variantList)?"
. "(?:$s$extensionList)?"
. "(?:$s$privateUse)?)";
# Here is the final breakdown, with capturing groups for each of these components
# The variants, extensions, legacy, and private-use may have interior '-'
$root = "^(?:$langtag|$privateUse|$legacy)$";
return preg_match( "/$root/i", $code );
}
}
/** @deprecated class alias since 1.43 */
class_alias( LanguageCode::class, 'LanguageCode' );