| // 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); |