return string(x)
	case []Value:
		b, _ := json.Marshal(x)
		return string(b)

	default:
		return "CSV serialization not implemented for this type"
	}
}

// negate negates a numeric value
func (v *Value) negate() {
	switch x := v.value.(type) {
	case float64:
		v.value = -x
	case int64:
		v.value = -x
	}
}

// Value comparison functions: we do not expose them outside the

	l.mutex.Lock()
	defer l.mutex.Unlock()
	if _, reply = l.lockMap[args.Resources[0]]; !reply {
		l.lockMap[args.Resources[0]] = WriteLock // No locks held on the given name, so claim write lock
	}
	reply = !reply // Negate *reply to return true when lock is granted or false otherwise
	return reply, nil
}

func (l *lockServer) Unlock(args *LockArgs) (reply bool, err error) {
	if d := atomic.LoadInt64(&l.responseDelay); d != 0 {

	if e.Negated == nil {
		return e.Primary.evalNode(r, tableAlias)
	}

	v, err := e.Negated.Term.evalNode(r, tableAlias)
	if err != nil {
		return nil, err
	}

	inferTypeForArithOp(v)
	v.negate()
	if v.isNumeric() {
		return v, nil
	}
	return nil, errArithMismatchedTypes
}

func (e *JSONPath) evalNode(r Record, tableAlias string) (*Value, error) {
	alias := tableAlias
	if tableAlias == "" {

// including timezone is ignored.
func dateDiff(timePart string, ts1, ts2 time.Time) (*Value, error) {
	if ts2.Before(ts1) {
		v, err := dateDiff(timePart, ts2, ts1)
		if err == nil {
			v.negate()
		}
		return v, err
	}

	duration := ts2.Sub(ts1)
	y1, m1, d1 := ts1.Date()
	y2, m2, d2 := ts2.Date()

	switch timePart {
	case timePartYear:
		dy := int64(y2 - y1)