Method doAdd

base/src/main/java/net/time4j/PlainDate.java:1749–1807

Additionsmethode. @param unit calendar unit @param context calendar date @param amount amount to be added @param policy overflow policy @return result of addition

(
        CalendarUnit unit,
        PlainDate context,
        long amount,
        int policy
    )

     * @return  result of addition
     */
    static PlainDate doAdd(
        CalendarUnit unit,
        PlainDate context,
        long amount,
        int policy
    ) {

        switch (unit) {
            case MILLENNIA:
                return doAdd(
                    CalendarUnit.MONTHS,
                    context,
                    MathUtils.safeMultiply(amount, 12 * 1000),
                    policy);
            case CENTURIES:
                return doAdd(
                    CalendarUnit.MONTHS,
                    context,
                    MathUtils.safeMultiply(amount, 12 * 100),
                    policy);
            case DECADES:
                return doAdd(
                    CalendarUnit.MONTHS,
                    context,
                    MathUtils.safeMultiply(amount, 12 * 10),
                    policy);
            case YEARS:
                return doAdd(
                    CalendarUnit.MONTHS,
                    context,
                    MathUtils.safeMultiply(amount, 12),
                    policy);
            case QUARTERS:
                return doAdd(
                    CalendarUnit.MONTHS,
                    context,
                    MathUtils.safeMultiply(amount, 3),
                    policy);
            case MONTHS:
                long months =
                    MathUtils.safeAdd(context.getEpochMonths(), amount);
                return PlainDate.fromEpochMonths(
                    context,
                    months,
                    context.dayOfMonth,
                    policy);
            case WEEKS:
                return doAdd(
                    CalendarUnit.DAYS,
                    context,
                    MathUtils.safeMultiply(amount, 7),
                    policy);
            case DAYS:
                return addDays(context, amount);
            default:
                throw new UnsupportedOperationException(unit.name());
        }