示例#1
0
// Parses an ISO8601 (with designators) string.
// See the following links for examples:
//  - http://www.postgresql.org/docs/9.1/static/datatype-datetime.html#DATATYPE-INTERVAL-INPUT-EXAMPLES
//  - https://en.wikipedia.org/wiki/ISO_8601#Time_intervals
//  - https://en.wikipedia.org/wiki/ISO_8601#Durations
func iso8601ToDuration(s string) (duration.Duration, error) {
	var d duration.Duration
	if len(s) == 0 || s[0] != 'P' {
		return d, fmt.Errorf("interval: invalid iso8601 duration %s", s)
	}

	// Advance to offset 1, since we don't care about the leading P.
	l := intervalLexer{str: s, offset: 1, err: nil}
	unitMap := isoDateUnitMap

	for l.offset < len(s) {
		// Check if we're in the time part yet.
		if s[l.offset] == 'T' {
			unitMap = isoTimeUnitMap
			l.offset++
		}

		v := l.consumeInt()
		u := l.consumeUnit('T')
		if l.err != nil {
			return d, l.err
		}

		if unit, ok := unitMap[u]; ok {
			d = d.Add(unit.Mul(v))
		} else {
			return d, fmt.Errorf("interval: unknown unit %s in iso8601 duration %s", u, s)
		}
	}

	return d, nil
}
示例#2
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// EncodeDurationDescending is the descending version of EncodeDurationAscending.
func EncodeDurationDescending(b []byte, d duration.Duration) ([]byte, error) {
	sortNanos, months, days, err := d.Encode()
	if err != nil {
		// TODO(dan): Handle this using d.EncodeBigInt() and the
		// durationBigNeg/durationBigPos markers.
		return b, err
	}
	b = append(b, durationMarker)
	b = EncodeVarintDescending(b, sortNanos)
	b = EncodeVarintDescending(b, months)
	b = EncodeVarintDescending(b, days)
	return b, nil
}
示例#3
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// Parses a duration in the "traditional" Postgres format.
func postgresToDuration(s string) (duration.Duration, error) {
	var d duration.Duration
	l := intervalLexer{str: s, offset: 0, err: nil}
	for l.offset != len(l.str) {
		v := l.consumeInt()
		l.consumeSpaces()
		u := l.consumeUnit(' ')
		l.consumeSpaces()
		if unit, ok := postgresUnitMap[u]; ok {
			d = d.Add(unit.Mul(v))
		} else {
			return d, fmt.Errorf("interval: unknown unit %s in postgres duration %s", u, s)
		}
	}

	return d, nil
}