add method

dynamic add(int val, String unit)

Add val by unit. Supports shorthand.

Example:

add(1, 'date');
add(1, 'd');

Implementation

dynamic add(int val, String unit) {
  final processedUnit = Unit.fromShorthand(unit);
  final duration = u.durationFromUnit(val, processedUnit);

  if (duration != null) {
    final d = clone();

    d._time = d._time.add(duration);
    d._parseTime();

    return d;
  } else {
    if (unit == Unit.y || unit == 'y') {
      return _cloneAndSetSingleValue(Unit.y, year() + val);
    } else if (unit == Unit.m || unit == 'M') {
      final int result = month() + val;

      final d = clone();
      if (result > 0) {
        d.setValue(Unit.m, result);
      } else {
        d
          ..setValue(Unit.y, d.year() - (result.abs() ~/ 12 + 1))
          ..setValue(Unit.m, 12 - result.abs() % 12);
      }
      d.finished();

      return d;
    }
  }

  return null;
}