lib/src/locale/locale_parser.dart - intl - Git at Google

 // Copyright (c) 2019, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.

 import 'locale_deprecations.dart';
 import 'locale_extensions.dart';
 import 'locale_implementation.dart';

 /// A parser for [Unicode Locale
 /// Identifiers](https://www.unicode.org/reports/tr35/#Unicode_locale_identifier).
 class LocaleParser {
   /// Language subtag of Unicode Language Identifier.
   String _languageCode = 'und';

   /// Script subtag of Unicode Language Identifier.
   String _scriptCode;

   /// Region subtag of Unicode Language Identifier.
   String _countryCode;

   /// Variant subtags of Unicode Language Identifier.
   List<String> _variants;

   /// Unicode Locale Extensions, also known as "U Extension".
   Map<String, String> _uExtensions;

   /// Transformed Extensions, also known as "T Extension".
   Map<String, String> _tExtensions;

   /// Private-Use Extensions.
   String _xExtensions;

   /// Other Extensions.
   Map<String, String> _otherExtensions;

   /// List of problems with the localeId the parser tried to parse.
   ///
   /// An empty list indicates problem-free parsing.
   final List<String> problems = <String>[];

   /// Produces a Locale instance for the parser's current state.
   ///
   /// Returns null if the Locale would be syntactically invalid.
   LocaleImplementation toLocale() {
     if (problems.isNotEmpty) return null;
     LocaleExtensions extensions;
     if (_uExtensions != null ||
         _tExtensions != null ||
         _otherExtensions != null ||
         _xExtensions != null) {
       extensions = LocaleExtensions(
           _uExtensions, _tExtensions, _otherExtensions, _xExtensions);
     }
     return LocaleImplementation.unsafe(
       _languageCode,
       scriptCode: _scriptCode,
       countryCode: _countryCode,
       variants: _variants,
       extensions: extensions,
     );
   }

   /// Subtags of the Locale Identifier, as split by [separators].
   List<String> _subtags;

   /// RegExp that matches Unicode Locale Identifier subtag separators.
   static final separators = RegExp('[-_]');

   /// Last accepted subtag.
   String _accepted;

   /// Last accepted subtag.
   String accepted() => _accepted;

   /// Last accepted list of subtags (for variants).
   List<String> _acceptedList;

   /// Last accepted list of subtags (for variants).
   List<String> acceptedList() => _acceptedList;

   /// Current subtag pending acceptance.
   String _current;

   /// Current subtag pending acceptance.
   String current() => _current;

   /// Index of the current subtag.
   int _currentIndex;

   /// Advance to the next subtag (see [current] and [accepted]).
   void advance() {
     _accepted = _current;
     _currentIndex++;
     if (_currentIndex < _subtags.length) {
       _current = _subtags[_currentIndex];
     } else {
       _current = null;
     }
   }

   /// Returns true if all subtags have been parsed.
   bool atEnd() {
     return _currentIndex >= _subtags.length;
   }

   /// Parses [Unicode CLDR Locale
   /// Identifiers](https://www.unicode.org/reports/tr35/#Identifiers).
   ///
   /// This method does not parse all BCP 47 tags. See [BCP 47
   /// Conformance](https://www.unicode.org/reports/tr35/#BCP_47_Conformance) for
   /// details.
   ///
   /// localeId may not be null.
   ///
   /// Parsing failed if there are any entries in [problems].
   LocaleParser(String localeId) {
     assert(localeId != null);

     // Calling toLowerCase unconditionally should be efficient if
     // string_patch.dart is in use:
     // https://github.com/dart-lang/sdk/blob/cabaa78cc57d08bcfcd75bfe99a42c19ed497d26/runtime/lib/string_patch.dart#L1178
     localeId = localeId.toLowerCase();
     if (localeId == 'root') {
       return;
     }

     _subtags = localeId.split(separators);
     _currentIndex = 0;
     _current = _subtags[0];

     var scriptFound = false;
     if (acceptLanguage()) {
       _languageCode = replaceDeprecatedLanguageSubtag(accepted());
       scriptFound = acceptScript();
     } else {
       scriptFound = acceptScript();
       if (!scriptFound) {
         problems.add('bad language/script');
       }
     }
     if (scriptFound) {
       _scriptCode = toCapCase(accepted());
     }
     if (acceptRegion()) {
       _countryCode = replaceDeprecatedRegionSubtag(accepted().toUpperCase());
     }
     acceptVariants();
     _variants = acceptedList();

     processExtensions();

     if (!atEnd()) {
       problems.add('bad subtag "${current()}"');
     }
   }

   /// Consumes all remaining subtags, if syntactically valid.
   ///
   /// If parsing fails, `atEnd()` will be false and/or [problems] will not be
   /// empty.
   void processExtensions() {
     while (acceptSingleton()) {
       var singleton = accepted();
       if (singleton == 'u') {
         processUExtensions();
       } else if (singleton == 't') {
         processTExtensions();
       } else if (singleton == 'x') {
         processPrivateUseExtensions();
         break;
       } else {
         processOtherExtensions(singleton);
       }
     }
   }

   /// Consumes tags matched by `unicode_locale_extensions` in the specification,
   /// except that the 'u' singleton must already be accepted.
   ///
   /// If parsing fails, `atEnd()` will be false and/or [problems] will not be
   /// empty.
   void processUExtensions() {
     if (_uExtensions != null) {
       problems.add('duplicate "u"');
       return;
     }
     _uExtensions = <String, String>{};
     var empty = true;
     final attributes = <String>[];
     while (acceptLowAlphaNumeric3to8()) {
       attributes.add(accepted());
     }
     if (attributes.isNotEmpty) {
       empty = false;
       attributes.sort();
       _uExtensions[''] = attributes.join('-');
     }
     // unicode_locale_extensions: collect "(sep keyword)*".
     while (acceptUExtensionKey()) {
       empty = false;
       var key = accepted();
       final typeParts = <String>[];
       while (acceptLowAlphaNumeric3to8()) {
         typeParts.add(accepted());
       }
       if (!_uExtensions.containsKey(key)) {
         if (typeParts.length == 1 && typeParts[0] == 'true') {
           _uExtensions[key] = '';
         } else {
           _uExtensions[key] = typeParts.join('-');
         }
       } else {
         problems.add('duplicate "$key"');
       }
     }
     if (empty) {
       problems.add('empty "u"');
     }
   }

   /// Consumes tags matched by `transformed_extensions` in the specification,
   /// except that the 't' singleton must already be accepted.
   ///
   /// If parsing fails, `atEnd()` will be false and/or [problems] will not be
   /// empty.
   void processTExtensions() {
     if (_tExtensions != null) {
       problems.add('duplicate "t"');
       return;
     }
     _tExtensions = <String, String>{};
     var empty = true;
     final tlang = <String>[];
     if (acceptLanguage()) {
       empty = false;
       tlang.add(replaceDeprecatedLanguageSubtag(accepted()));
       if (acceptScript()) {
         tlang.add(accepted());
       }
       if (acceptRegion()) {
         tlang.add(replaceDeprecatedRegionSubtag(accepted().toUpperCase())
             .toLowerCase());
       }
       acceptVariants();
       tlang.addAll(acceptedList());
       _tExtensions[''] = tlang.join('-');
     }
     // transformed_extensions: collect "(sep tfield)*".
     while (acceptTExtensionKey()) {
       var tkey = accepted();
       final tvalueParts = <String>[];
       while (acceptLowAlphaNumeric3to8()) {
         tvalueParts.add(accepted());
       }
       if (tvalueParts.isNotEmpty) {
         empty = false;
         if (!_tExtensions.containsKey(tkey)) {
           _tExtensions[tkey] = tvalueParts.join('-');
         } else {
           problems.add('duplicate "$tkey"');
         }
       } else {
         problems.add('empty "$tkey"');
       }
     }
     if (empty) {
       problems.add('empty "t"');
     }
   }

   /// Consumes tags matched by `pu_extensions` in the specification, except that
   /// the 'x' singleton must already be accepted.
   ///
   /// If parsing fails, `atEnd()` will be false and/or [problems] will not be
   /// empty.
   void processPrivateUseExtensions() {
     final values = <String>[];
     while (acceptLowAlphaNumeric1to8()) {
       values.add(accepted());
     }
     if (values.isNotEmpty) {
       _xExtensions = values.join('-');
     }
   }

   /// Consumes tags matched by `other_extensions` in the specification, except
   /// that the singleton in question must already be accepted and passed as
   /// parameter.
   ///
   /// If parsing fails, `atEnd()` will be false and/or [problems] will not be
   /// empty.
   void processOtherExtensions(String singleton) {
     final values = <String>[];
     while (acceptLowAlphaNumeric2to8()) {
       values.add(accepted());
     }
     if (values.isEmpty) return;
     if (_otherExtensions == null) {
       _otherExtensions = <String, String>{};
     } else if (_otherExtensions.containsKey(singleton)) {
       problems.add('duplicate "$singleton"');
       return;
     }
     _otherExtensions[singleton] = values.join('-');
   }

   /// Advances and returns true if current subtag is a language subtag.
   bool acceptLanguage() {
     if (atEnd()) return false;
     if (!_languageRegExp.hasMatch(current())) return false;
     advance();
     return true;
   }

   static final _languageRegExp = RegExp(r'^[a-z]{2,3}$|^[a-z]{5,8}$');

   /// Advances and returns true if current subtag is a script subtag.
   bool acceptScript() {
     if (atEnd()) return false;
     if (!_scriptRegExp.hasMatch(current())) return false;
     advance();
     return true;
   }

   static final _scriptRegExp = RegExp(r'^[a-z]{4}$');

   /// Advances and returns true if current subtag is a region subtag.
   bool acceptRegion() {
     if (atEnd()) return false;
     if (!_regionRegExp.hasMatch(current())) return false;
     advance();
     return true;
   }

   static final _regionRegExp = RegExp(r'^[a-z]{2}$|^\d{3}$');

   /// Advances, collecting subtags in [_acceptedList], as long as the current
   /// subtag is a variant subtag.
   ///
   /// Does not return a boolean: when done, _acceptedList will contain the
   /// collected subtags.
   void acceptVariants() {
     _acceptedList = [];
     while (!atEnd() && _variantRegExp.hasMatch(current())) {
       _acceptedList.add(current());
       advance();
     }
   }

   static final _variantRegExp = RegExp(r'^[a-z\d]{5,8}$|^\d[a-z\d]{3}$');

   /// Advances and returns true if current subtag is a singleton.
   bool acceptSingleton() {
     if (atEnd()) return false;
     if (!_singletonRegExp.hasMatch(current())) return false;
     advance();
     return true;
   }

   static final _singletonRegExp = RegExp(r'^[a-z]$');

   /// Advances and returns true if current subtag is alphanumeric, with length
   /// ranging from 1 to 8.
   bool acceptLowAlphaNumeric1to8() {
     if (atEnd()) return false;
     if (!_alphaNumeric1to8RegExp.hasMatch(current())) return false;
     advance();
     return true;
   }

   static final _alphaNumeric1to8RegExp = RegExp(r'^[a-z\d]{1,8}$');

   /// Advances and returns true if current subtag is alphanumeric, with length
   /// ranging from 2 to 8.
   bool acceptLowAlphaNumeric2to8() {
     if (atEnd()) return false;
     if (!_alphaNumeric1to8RegExp.hasMatch(current()) || current().length < 2) {
       return false;
     }
     advance();
     return true;
   }

   /// Advances and returns true if current subtag is alphanumeric, with length
   /// ranging from 3 to 8.
   bool acceptLowAlphaNumeric3to8() {
     if (atEnd()) return false;
     if (!_alphaNumeric1to8RegExp.hasMatch(current()) || current().length < 3) {
       return false;
     }
     advance();
     return true;
   }

   /// Advances and returns true if current subtag is a valid U Extension key.
   bool acceptUExtensionKey() {
     if (atEnd()) return false;
     if (!_uExtensionKeyRegExp.hasMatch(current())) return false;
     advance();
     return true;
   }

   static final _uExtensionKeyRegExp = RegExp(r'^[a-z\d][a-z]$');

   /// Advances and returns true if current subtag is a valid T Extension key
   /// (`tkey` in the specification).
   bool acceptTExtensionKey() {
     if (atEnd()) return false;
     if (!_tExtensionKeyRegExp.hasMatch(current())) return false;
     advance();
     return true;
   }

   static final _tExtensionKeyRegExp = RegExp(r'^[a-z]\d$');
 }
	// Copyright (c) 2019, the Dart project authors. Please see the AUTHORS file
	// for details. All rights reserved. Use of this source code is governed by a
	// BSD-style license that can be found in the LICENSE file.

	import 'locale_deprecations.dart';
	import 'locale_extensions.dart';
	import 'locale_implementation.dart';

	/// A parser for [Unicode Locale
	/// Identifiers](https://www.unicode.org/reports/tr35/#Unicode_locale_identifier).
	class LocaleParser {
	/// Language subtag of Unicode Language Identifier.
	String _languageCode = 'und';

	/// Script subtag of Unicode Language Identifier.
	String _scriptCode;

	/// Region subtag of Unicode Language Identifier.
	String _countryCode;

	/// Variant subtags of Unicode Language Identifier.
	List<String> _variants;

	/// Unicode Locale Extensions, also known as "U Extension".
	Map<String, String> _uExtensions;

	/// Transformed Extensions, also known as "T Extension".
	Map<String, String> _tExtensions;

	/// Private-Use Extensions.
	String _xExtensions;

	/// Other Extensions.
	Map<String, String> _otherExtensions;

	/// List of problems with the localeId the parser tried to parse.
	///
	/// An empty list indicates problem-free parsing.
	final List<String> problems = <String>[];

	/// Produces a Locale instance for the parser's current state.
	///
	/// Returns null if the Locale would be syntactically invalid.
	LocaleImplementation toLocale() {
	if (problems.isNotEmpty) return null;
	LocaleExtensions extensions;
	if (_uExtensions != null \|\|
	_tExtensions != null \|\|
	_otherExtensions != null \|\|
	_xExtensions != null) {
	extensions = LocaleExtensions(
	_uExtensions, _tExtensions, _otherExtensions, _xExtensions);
	}
	return LocaleImplementation.unsafe(
	_languageCode,
	scriptCode: _scriptCode,
	countryCode: _countryCode,
	variants: _variants,
	extensions: extensions,
	);
	}

	/// Subtags of the Locale Identifier, as split by [separators].
	List<String> _subtags;

	/// RegExp that matches Unicode Locale Identifier subtag separators.
	static final separators = RegExp('[-_]');

	/// Last accepted subtag.
	String _accepted;

	/// Last accepted subtag.
	String accepted() => _accepted;

	/// Last accepted list of subtags (for variants).
	List<String> _acceptedList;

	/// Last accepted list of subtags (for variants).
	List<String> acceptedList() => _acceptedList;

	/// Current subtag pending acceptance.
	String _current;

	/// Current subtag pending acceptance.
	String current() => _current;

	/// Index of the current subtag.
	int _currentIndex;

	/// Advance to the next subtag (see [current] and [accepted]).
	void advance() {
	_accepted = _current;
	_currentIndex++;
	if (_currentIndex < _subtags.length) {
	_current = _subtags[_currentIndex];
	} else {
	_current = null;
	}
	}

	/// Returns true if all subtags have been parsed.
	bool atEnd() {
	return _currentIndex >= _subtags.length;
	}

	/// Parses [Unicode CLDR Locale
	/// Identifiers](https://www.unicode.org/reports/tr35/#Identifiers).
	///
	/// This method does not parse all BCP 47 tags. See [BCP 47
	/// Conformance](https://www.unicode.org/reports/tr35/#BCP_47_Conformance) for
	/// details.
	///
	/// localeId may not be null.
	///
	/// Parsing failed if there are any entries in [problems].
	LocaleParser(String localeId) {
	assert(localeId != null);

	// Calling toLowerCase unconditionally should be efficient if
	// string_patch.dart is in use:
	// https://github.com/dart-lang/sdk/blob/cabaa78cc57d08bcfcd75bfe99a42c19ed497d26/runtime/lib/string_patch.dart#L1178
	localeId = localeId.toLowerCase();
	if (localeId == 'root') {
	return;
	}

	_subtags = localeId.split(separators);
	_currentIndex = 0;
	_current = _subtags[0];

	var scriptFound = false;
	if (acceptLanguage()) {
	_languageCode = replaceDeprecatedLanguageSubtag(accepted());
	scriptFound = acceptScript();
	} else {
	scriptFound = acceptScript();
	if (!scriptFound) {
	problems.add('bad language/script');
	}
	}
	if (scriptFound) {
	_scriptCode = toCapCase(accepted());
	}
	if (acceptRegion()) {
	_countryCode = replaceDeprecatedRegionSubtag(accepted().toUpperCase());
	}
	acceptVariants();
	_variants = acceptedList();

	processExtensions();

	if (!atEnd()) {
	problems.add('bad subtag "${current()}"');
	}
	}

	/// Consumes all remaining subtags, if syntactically valid.
	///
	/// If parsing fails, `atEnd()` will be false and/or [problems] will not be
	/// empty.
	void processExtensions() {
	while (acceptSingleton()) {
	var singleton = accepted();
	if (singleton == 'u') {
	processUExtensions();
	} else if (singleton == 't') {
	processTExtensions();
	} else if (singleton == 'x') {
	processPrivateUseExtensions();
	break;
	} else {
	processOtherExtensions(singleton);
	}
	}
	}

	/// Consumes tags matched by `unicode_locale_extensions` in the specification,
	/// except that the 'u' singleton must already be accepted.
	///
	/// If parsing fails, `atEnd()` will be false and/or [problems] will not be
	/// empty.
	void processUExtensions() {
	if (_uExtensions != null) {
	problems.add('duplicate "u"');
	return;
	}
	_uExtensions = <String, String>{};
	var empty = true;
	final attributes = <String>[];
	while (acceptLowAlphaNumeric3to8()) {
	attributes.add(accepted());
	}
	if (attributes.isNotEmpty) {
	empty = false;
	attributes.sort();
	_uExtensions[''] = attributes.join('-');
	}
	// unicode_locale_extensions: collect "(sep keyword)*".
	while (acceptUExtensionKey()) {
	empty = false;
	var key = accepted();
	final typeParts = <String>[];
	while (acceptLowAlphaNumeric3to8()) {
	typeParts.add(accepted());
	}
	if (!_uExtensions.containsKey(key)) {
	if (typeParts.length == 1 && typeParts[0] == 'true') {
	_uExtensions[key] = '';
	} else {
	_uExtensions[key] = typeParts.join('-');
	}
	} else {
	problems.add('duplicate "$key"');
	}
	}
	if (empty) {
	problems.add('empty "u"');
	}
	}

	/// Consumes tags matched by `transformed_extensions` in the specification,
	/// except that the 't' singleton must already be accepted.
	///
	/// If parsing fails, `atEnd()` will be false and/or [problems] will not be
	/// empty.
	void processTExtensions() {
	if (_tExtensions != null) {
	problems.add('duplicate "t"');
	return;
	}
	_tExtensions = <String, String>{};
	var empty = true;
	final tlang = <String>[];
	if (acceptLanguage()) {
	empty = false;
	tlang.add(replaceDeprecatedLanguageSubtag(accepted()));
	if (acceptScript()) {
	tlang.add(accepted());
	}
	if (acceptRegion()) {
	tlang.add(replaceDeprecatedRegionSubtag(accepted().toUpperCase())
	.toLowerCase());
	}
	acceptVariants();
	tlang.addAll(acceptedList());
	_tExtensions[''] = tlang.join('-');
	}
	// transformed_extensions: collect "(sep tfield)*".
	while (acceptTExtensionKey()) {
	var tkey = accepted();
	final tvalueParts = <String>[];
	while (acceptLowAlphaNumeric3to8()) {
	tvalueParts.add(accepted());
	}
	if (tvalueParts.isNotEmpty) {
	empty = false;
	if (!_tExtensions.containsKey(tkey)) {
	_tExtensions[tkey] = tvalueParts.join('-');
	} else {
	problems.add('duplicate "$tkey"');
	}
	} else {
	problems.add('empty "$tkey"');
	}
	}
	if (empty) {
	problems.add('empty "t"');
	}
	}

	/// Consumes tags matched by `pu_extensions` in the specification, except that
	/// the 'x' singleton must already be accepted.
	///
	/// If parsing fails, `atEnd()` will be false and/or [problems] will not be
	/// empty.
	void processPrivateUseExtensions() {
	final values = <String>[];
	while (acceptLowAlphaNumeric1to8()) {
	values.add(accepted());
	}
	if (values.isNotEmpty) {
	_xExtensions = values.join('-');
	}
	}

	/// Consumes tags matched by `other_extensions` in the specification, except
	/// that the singleton in question must already be accepted and passed as
	/// parameter.
	///
	/// If parsing fails, `atEnd()` will be false and/or [problems] will not be
	/// empty.
	void processOtherExtensions(String singleton) {
	final values = <String>[];
	while (acceptLowAlphaNumeric2to8()) {
	values.add(accepted());
	}
	if (values.isEmpty) return;
	if (_otherExtensions == null) {
	_otherExtensions = <String, String>{};
	} else if (_otherExtensions.containsKey(singleton)) {
	problems.add('duplicate "$singleton"');
	return;
	}
	_otherExtensions[singleton] = values.join('-');
	}

	/// Advances and returns true if current subtag is a language subtag.
	bool acceptLanguage() {
	if (atEnd()) return false;
	if (!_languageRegExp.hasMatch(current())) return false;
	advance();
	return true;
	}

	static final _languageRegExp = RegExp(r'^[a-z]{2,3}$\|^[a-z]{5,8}$');

	/// Advances and returns true if current subtag is a script subtag.
	bool acceptScript() {
	if (atEnd()) return false;
	if (!_scriptRegExp.hasMatch(current())) return false;
	advance();
	return true;
	}

	static final _scriptRegExp = RegExp(r'^[a-z]{4}$');

	/// Advances and returns true if current subtag is a region subtag.
	bool acceptRegion() {
	if (atEnd()) return false;
	if (!_regionRegExp.hasMatch(current())) return false;
	advance();
	return true;
	}

	static final _regionRegExp = RegExp(r'^[a-z]{2}$\|^\d{3}$');

	/// Advances, collecting subtags in [_acceptedList], as long as the current
	/// subtag is a variant subtag.
	///
	/// Does not return a boolean: when done, _acceptedList will contain the
	/// collected subtags.
	void acceptVariants() {
	_acceptedList = [];
	while (!atEnd() && _variantRegExp.hasMatch(current())) {
	_acceptedList.add(current());
	advance();
	}
	}

	static final _variantRegExp = RegExp(r'^[a-z\d]{5,8}$\|^\d[a-z\d]{3}$');

	/// Advances and returns true if current subtag is a singleton.
	bool acceptSingleton() {
	if (atEnd()) return false;
	if (!_singletonRegExp.hasMatch(current())) return false;
	advance();
	return true;
	}

	static final _singletonRegExp = RegExp(r'^[a-z]$');

	/// Advances and returns true if current subtag is alphanumeric, with length
	/// ranging from 1 to 8.
	bool acceptLowAlphaNumeric1to8() {
	if (atEnd()) return false;
	if (!_alphaNumeric1to8RegExp.hasMatch(current())) return false;
	advance();
	return true;
	}

	static final _alphaNumeric1to8RegExp = RegExp(r'^[a-z\d]{1,8}$');

	/// Advances and returns true if current subtag is alphanumeric, with length
	/// ranging from 2 to 8.
	bool acceptLowAlphaNumeric2to8() {
	if (atEnd()) return false;
	if (!_alphaNumeric1to8RegExp.hasMatch(current()) \|\| current().length < 2) {
	return false;
	}
	advance();
	return true;
	}

	/// Advances and returns true if current subtag is alphanumeric, with length
	/// ranging from 3 to 8.
	bool acceptLowAlphaNumeric3to8() {
	if (atEnd()) return false;
	if (!_alphaNumeric1to8RegExp.hasMatch(current()) \|\| current().length < 3) {
	return false;
	}
	advance();
	return true;
	}

	/// Advances and returns true if current subtag is a valid U Extension key.
	bool acceptUExtensionKey() {
	if (atEnd()) return false;
	if (!_uExtensionKeyRegExp.hasMatch(current())) return false;
	advance();
	return true;
	}

	static final _uExtensionKeyRegExp = RegExp(r'^[a-z\d][a-z]$');

	/// Advances and returns true if current subtag is a valid T Extension key
	/// (`tkey` in the specification).
	bool acceptTExtensionKey() {
	if (atEnd()) return false;
	if (!_tExtensionKeyRegExp.hasMatch(current())) return false;
	advance();
	return true;
	}

	static final _tExtensionKeyRegExp = RegExp(r'^[a-z]\d$');
	}