tryParse static method

XPathDuration? tryParse(String value, [ XPathType type = xsDuration ])

Attempts to parse a string representation of a duration.

Implementation

static XPathDuration? tryParse(String value, [XPathType type = xsDuration]) {
  if (type == xsYearMonthDuration) {
    return tryParseYearMonth(value);
  }
  if (type == xsDayTimeDuration) {
    return tryParseDayTime(value);
  }
  final match = _durationRegExp.firstMatch(value);
  if (match == null) return null;

  final hasYM = match.group(2) != null || match.group(3) != null;
  final hasDT =
      match.group(4) != null ||
      match.group(5) != null ||
      match.group(6) != null ||
      match.group(7) != null;
  if (!hasYM && !hasDT) return null;

  final negative = match.group(1) == '-';
  final yr = int.tryParse(match.group(2) ?? '0') ?? 0;
  final mo = int.tryParse(match.group(3) ?? '0') ?? 0;
  final dy = int.tryParse(match.group(4) ?? '0') ?? 0;
  final hr = int.tryParse(match.group(5) ?? '0') ?? 0;
  final min = int.tryParse(match.group(6) ?? '0') ?? 0;
  final scDouble = double.tryParse(match.group(7) ?? '0') ?? 0.0;
  final totalSeconds = scDouble.truncate();
  final frac = scDouble - totalSeconds;
  final ms = (frac * 1000).truncate();
  final us = ((frac * 1000000) - (ms * 1000)).round();

  final sec = totalSeconds % 60;
  final totalMin = min + totalSeconds ~/ 60;
  final m = totalMin % 60;
  final totalHr = hr + totalMin ~/ 60;
  final h = totalHr % 24;
  final d = dy + totalHr ~/ 24;

  return XPathDuration(
    years: yr,
    months: mo,
    days: d,
    hours: h,
    minutes: m,
    seconds: sec,
    milliseconds: ms,
    microseconds: us,
    isNegative: negative,
    type: type,
  );
}