pluralLogic method

Implementation

static pluralLogic(int howMany,
    {zero, one, two, few, many, other, String locale, String meaning}) {
  if (other == null) {
    throw new ArgumentError("The 'other' named argument must be provided");
  }
  if (howMany == null) {
    throw new ArgumentError("The howMany argument to plural cannot be null");
  }
  // If there's an explicit case for the exact number, we use it. This is not
  // strictly in accord with the CLDR rules, but it seems to be the
  // expectation. At least I see e.g. Russian translations that have a zero
  // case defined. The rule for that locale will never produce a zero, and
  // treats it as other. But it seems reasonable that, even if the language
  // rules treat zero as other, we might want a special message for zero.
  if (howMany == 0 && zero != null) return zero;
  if (howMany == 1 && one != null) return one;
  if (howMany == 2 && two != null) return two;
  var pluralRule = _pluralRule(locale, howMany);
  var pluralCase = pluralRule();
  switch (pluralCase) {
    case plural_rules.PluralCase.ZERO:
      return zero ?? other;
    case plural_rules.PluralCase.ONE:
      return one ?? other;
    case plural_rules.PluralCase.TWO:
      return two ?? few ?? other;
    case plural_rules.PluralCase.FEW:
      return few ?? other;
    case plural_rules.PluralCase.MANY:
      return many ?? other;
    case plural_rules.PluralCase.OTHER:
      return other;
    default:
      throw new ArgumentError.value(
          howMany, "howMany", "Invalid plural argument");
  }
}