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 // Copyright (c) 2016, 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. /// Provides locale-specific plural rules. Based on pluralrules.js from Closure. /// /// Each function does the calculation for one or more locales. These are done in terms of /// various values used by the CLDR syntax and defined by UTS #35 /// http://unicode.org/reports/tr35/tr35-numbers.html#Plural_rules_syntax /// /// * n - absolute value of the source number (integer and decimals). /// * i - integer digits of n. /// * v - number of visible fraction digits in n, with trailing zeros. /// * w - number of visible fraction digits in n, without trailing zeros. /// * f - visible fractional digits in n, with trailing zeros. /// * t - visible fractional digits in n, without trailing zeros. library plural_rules; // Suppress naming issues as changing them might be breaking. // ignore_for_file: constant_identifier_names, non_constant_identifier_names import 'dart:math' as math; typedef PluralRule = PluralCase Function(); /// The possible cases used in a plural rule. enum PluralCase { ZERO, ONE, TWO, FEW, MANY, OTHER } /// The default rule in case we don't have anything more specific for a locale. PluralCase _default_rule() => OTHER; /// This must be called before evaluating a new rule, because we're using /// library-global state to both keep the rules terse and minimize space. void startRuleEvaluation(num howMany, [int precision = 0]) { _n = howMany; _precision = precision; _i = _n.round(); _updateVF(_n, _precision); _updateWT(_f, _v); } /// The number whose [PluralCase] we are trying to find. /// // This is library-global state, along with the other variables. This allows us // to avoid calculating parameters that the functions don't need and also // not introduce a subclass per locale or have instance tear-offs which // we can't cache. This is fine as long as these methods aren't async, which // they should never be. num _n; /// The integer part of [_n] int _i; int _precision; /// Returns the number of digits in the fractional part of a number /// (3.1416 => 4) /// /// Takes the item count [n] and a [precision]. /// That's because a just looking at the value of a number is not enough to /// decide the plural form. For example "1 dollar" vs "1.00 dollars", the /// value is 1, but how it is formatted also matters. int _decimals(num n, int precision) { var str = _precision == null ? '\$n' : n.toStringAsFixed(precision); var result = str.indexOf('.'); return (result == -1) ? 0 : str.length - result - 1; } /// Calculates and sets the _v and _f as per CLDR plural rules. /// /// The short names for parameters / return match the CLDR syntax and UTS #35 /// (https://unicode.org/reports/tr35/tr35-numbers.html#Plural_rules_syntax) /// Takes the item count [n] and a [precision]. void _updateVF(num n, int precision) { var defaultDigits = 3; _v = precision ?? math.min(_decimals(n, precision), defaultDigits); var base = math.pow(10, _v) as int; _f = (n * base).floor() % base; } /// Calculates and sets _w and _t as per CLDR plural rules. /// /// The short names for parameters / return match the CLDR syntax and UTS #35 /// (https://unicode.org/reports/tr35/tr35-numbers.html#Plural_rules_syntax) /// @param v Calculated previously. /// @param f Calculated previously. void _updateWT(int v, int f) { if (f == 0) { // Unused, for now _w = 0; _t = 0; return; } while ((f % 10) == 0) { f = (f / 10).floor(); v--; } // Unused, for now _w = v; _t = f; } /// Number of visible fraction digits. int _v = 0; /// Number of visible fraction digits without trailing zeros. // Unused, for now int _w = 0; /// The visible fraction digits in n, with trailing zeros. int _f = 0; /// The visible fraction digits in n, without trailing zeros. int _t = 0; // An example, for precision n = 3.1415 and precision = 7) // n : 3.1415 // str n: 3.1415000 (the "formatted" n, 7 fractional digits) // i : 3 (the integer part of n) // f : 1415000 (the fractional part of n) // v : 7 (how many digits in f) // t : 1415 (f, without trailing 0s) // w : 4 (how many digits in t) PluralCase get ZERO => PluralCase.ZERO; PluralCase get ONE => PluralCase.ONE; PluralCase get TWO => PluralCase.TWO; PluralCase get FEW => PluralCase.FEW; PluralCase get MANY => PluralCase.MANY; PluralCase get OTHER => PluralCase.OTHER; PluralCase _fil_rule() { if (_v == 0 && (_i == 1 || _i == 2 || _i == 3) || _v == 0 && _i % 10 != 4 && _i % 10 != 6 && _i % 10 != 9 || _v != 0 && _f % 10 != 4 && _f % 10 != 6 && _f % 10 != 9) { return ONE; } return OTHER; } PluralCase _pt_PT_rule() { if (_n == 1 && _v == 0) { return ONE; } return OTHER; } PluralCase _br_rule() { if (_n % 10 == 1 && _n % 100 != 11 && _n % 100 != 71 && _n % 100 != 91) { return ONE; } if (_n % 10 == 2 && _n % 100 != 12 && _n % 100 != 72 && _n % 100 != 92) { return TWO; } if ((_n % 10 >= 3 && _n % 10 <= 4 || _n % 10 == 9) && (_n % 100 < 10 || _n % 100 > 19) && (_n % 100 < 70 || _n % 100 > 79) && (_n % 100 < 90 || _n % 100 > 99)) { return FEW; } if (_n != 0 && _n % 1000000 == 0) { return MANY; } return OTHER; } PluralCase _sr_rule() { if (_v == 0 && _i % 10 == 1 && _i % 100 != 11 || _f % 10 == 1 && _f % 100 != 11) { return ONE; } if (_v == 0 && _i % 10 >= 2 && _i % 10 <= 4 && (_i % 100 < 12 || _i % 100 > 14) || _f % 10 >= 2 && _f % 10 <= 4 && (_f % 100 < 12 || _f % 100 > 14)) { return FEW; } return OTHER; } PluralCase _ro_rule() { if (_i == 1 && _v == 0) { return ONE; } if (_v != 0 || _n == 0 || _n != 1 && _n % 100 >= 1 && _n % 100 <= 19) { return FEW; } return OTHER; } PluralCase _hi_rule() { if (_i == 0 || _n == 1) { return ONE; } return OTHER; } PluralCase _fr_rule() { if (_i == 0 || _i == 1) { return ONE; } return OTHER; } PluralCase _cs_rule() { if (_i == 1 && _v == 0) { return ONE; } if (_i >= 2 && _i <= 4 && _v == 0) { return FEW; } if (_v != 0) { return MANY; } return OTHER; } PluralCase _pl_rule() { if (_i == 1 && _v == 0) { return ONE; } if (_v == 0 && _i % 10 >= 2 && _i % 10 <= 4 && (_i % 100 < 12 || _i % 100 > 14)) { return FEW; } if (_v == 0 && _i != 1 && _i % 10 >= 0 && _i % 10 <= 1 || _v == 0 && _i % 10 >= 5 && _i % 10 <= 9 || _v == 0 && _i % 100 >= 12 && _i % 100 <= 14) { return MANY; } return OTHER; } PluralCase _lv_rule() { if (_n % 10 == 0 || _n % 100 >= 11 && _n % 100 <= 19 || _v == 2 && _f % 100 >= 11 && _f % 100 <= 19) { return ZERO; } if (_n % 10 == 1 && _n % 100 != 11 || _v == 2 && _f % 10 == 1 && _f % 100 != 11 || _v != 2 && _f % 10 == 1) { return ONE; } return OTHER; } PluralCase _he_rule() { if (_i == 1 && _v == 0) { return ONE; } if (_i == 2 && _v == 0) { return TWO; } if (_v == 0 && (_n < 0 || _n > 10) && _n % 10 == 0) { return MANY; } return OTHER; } PluralCase _mt_rule() { if (_n == 1) { return ONE; } if (_n == 0 || _n % 100 >= 2 && _n % 100 <= 10) { return FEW; } if (_n % 100 >= 11 && _n % 100 <= 19) { return MANY; } return OTHER; } PluralCase _si_rule() { if ((_n == 0 || _n == 1) || _i == 0 && _f == 1) { return ONE; } return OTHER; } PluralCase _cy_rule() { if (_n == 0) { return ZERO; } if (_n == 1) { return ONE; } if (_n == 2) { return TWO; } if (_n == 3) { return FEW; } if (_n == 6) { return MANY; } return OTHER; } PluralCase _da_rule() { if (_n == 1 || _t != 0 && (_i == 0 || _i == 1)) { return ONE; } return OTHER; } PluralCase _ru_rule() { if (_v == 0 && _i % 10 == 1 && _i % 100 != 11) { return ONE; } if (_v == 0 && _i % 10 >= 2 && _i % 10 <= 4 && (_i % 100 < 12 || _i % 100 > 14)) { return FEW; } if (_v == 0 && _i % 10 == 0 || _v == 0 && _i % 10 >= 5 && _i % 10 <= 9 || _v == 0 && _i % 100 >= 11 && _i % 100 <= 14) { return MANY; } return OTHER; } PluralCase _be_rule() { if (_n % 10 == 1 && _n % 100 != 11) { return ONE; } if (_n % 10 >= 2 && _n % 10 <= 4 && (_n % 100 < 12 || _n % 100 > 14)) { return FEW; } if (_n % 10 == 0 || _n % 10 >= 5 && _n % 10 <= 9 || _n % 100 >= 11 && _n % 100 <= 14) { return MANY; } return OTHER; } PluralCase _mk_rule() { if (_v == 0 && _i % 10 == 1 || _f % 10 == 1) { return ONE; } return OTHER; } PluralCase _ga_rule() { if (_n == 1) { return ONE; } if (_n == 2) { return TWO; } if (_n >= 3 && _n <= 6) { return FEW; } if (_n >= 7 && _n <= 10) { return MANY; } return OTHER; } PluralCase _pt_rule() { if (_n >= 0 && _n <= 2 && _n != 2) { return ONE; } return OTHER; } PluralCase _es_rule() { if (_n == 1) { return ONE; } return OTHER; } PluralCase _is_rule() { if (_t == 0 && _i % 10 == 1 && _i % 100 != 11 || _t != 0) { return ONE; } return OTHER; } PluralCase _ar_rule() { if (_n == 0) { return ZERO; } if (_n == 1) { return ONE; } if (_n == 2) { return TWO; } if (_n % 100 >= 3 && _n % 100 <= 10) { return FEW; } if (_n % 100 >= 11 && _n % 100 <= 99) { return MANY; } return OTHER; } PluralCase _sl_rule() { if (_v == 0 && _i % 100 == 1) { return ONE; } if (_v == 0 && _i % 100 == 2) { return TWO; } if (_v == 0 && _i % 100 >= 3 && _i % 100 <= 4 || _v != 0) { return FEW; } return OTHER; } PluralCase _lt_rule() { if (_n % 10 == 1 && (_n % 100 < 11 || _n % 100 > 19)) { return ONE; } if (_n % 10 >= 2 && _n % 10 <= 9 && (_n % 100 < 11 || _n % 100 > 19)) { return FEW; } if (_f != 0) { return MANY; } return OTHER; } PluralCase _en_rule() { if (_i == 1 && _v == 0) { return ONE; } return OTHER; } PluralCase _ak_rule() { if (_n >= 0 && _n <= 1) { return ONE; } return OTHER; } /// Selected Plural rules by locale. final pluralRules = { 'af': _es_rule, 'am': _hi_rule, 'ar': _ar_rule, 'az': _es_rule, 'be': _be_rule, 'bg': _es_rule, 'bn': _hi_rule, 'br': _br_rule, 'bs': _sr_rule, 'ca': _en_rule, 'chr': _es_rule, 'cs': _cs_rule, 'cy': _cy_rule, 'da': _da_rule, 'de': _en_rule, 'de_AT': _en_rule, 'de_CH': _en_rule, 'el': _es_rule, 'en': _en_rule, 'en_AU': _en_rule, 'en_CA': _en_rule, 'en_GB': _en_rule, 'en_IE': _en_rule, 'en_IN': _en_rule, 'en_SG': _en_rule, 'en_US': _en_rule, 'en_ZA': _en_rule, 'es': _es_rule, 'es_419': _es_rule, 'es_ES': _es_rule, 'es_MX': _es_rule, 'es_US': _es_rule, 'et': _en_rule, 'eu': _es_rule, 'fa': _hi_rule, 'fi': _en_rule, 'fil': _fil_rule, 'fr': _fr_rule, 'fr_CA': _fr_rule, 'ga': _ga_rule, 'gl': _en_rule, 'gsw': _es_rule, 'gu': _hi_rule, 'haw': _es_rule, 'he': _he_rule, 'hi': _hi_rule, 'hr': _sr_rule, 'hu': _es_rule, 'hy': _fr_rule, 'id': _default_rule, 'in': _default_rule, 'is': _is_rule, 'it': _en_rule, 'iw': _he_rule, 'ja': _default_rule, 'ka': _es_rule, 'kk': _es_rule, 'km': _default_rule, 'kn': _hi_rule, 'ko': _default_rule, 'ky': _es_rule, 'ln': _ak_rule, 'lo': _default_rule, 'lt': _lt_rule, 'lv': _lv_rule, 'mk': _mk_rule, 'ml': _es_rule, 'mn': _es_rule, 'mo': _ro_rule, 'mr': _hi_rule, 'ms': _default_rule, 'mt': _mt_rule, 'my': _default_rule, 'nb': _es_rule, 'ne': _es_rule, 'nl': _en_rule, 'no': _es_rule, 'no_NO': _es_rule, 'or': _es_rule, 'pa': _ak_rule, 'pl': _pl_rule, 'pt': _pt_rule, 'pt_BR': _pt_rule, 'pt_PT': _pt_PT_rule, 'ro': _ro_rule, 'ru': _ru_rule, 'sh': _sr_rule, 'si': _si_rule, 'sk': _cs_rule, 'sl': _sl_rule, 'sq': _es_rule, 'sr': _sr_rule, 'sr_Latn': _sr_rule, 'sv': _en_rule, 'sw': _en_rule, 'ta': _es_rule, 'te': _es_rule, 'th': _default_rule, 'tl': _fil_rule, 'tr': _es_rule, 'uk': _ru_rule, 'ur': _en_rule, 'uz': _es_rule, 'vi': _default_rule, 'zh': _default_rule, 'zh_CN': _default_rule, 'zh_HK': _default_rule, 'zh_TW': _default_rule, 'zu': _hi_rule, 'default': _default_rule }; /// Do we have plural rules specific to [locale] bool localeHasPluralRules(String locale) => pluralRules.containsKey(locale);