Rational.parse constructor

Implementation

factory Rational.parse(String source) {
  final match = _regExp.firstMatch(source);
  if (match == null || match[0] == null) {
    return throw FormatException('Invalid Ratio', source);
  }

  final integer = int.parse(match.namedGroup('integer')!);
  if (match.namedGroup('numerator') == null) {
    return Rational.fromMixed(integer);
  }

  final numerator = int.parse(match.namedGroup('numerator')!);
  final denominator = int.parse(match.namedGroup('denominator')!);

  return Rational.fromMixed(integer, numerator, denominator);
}